US20020029050A1 - Devices and methods for performing a vascular anastomosis - Google Patents

Abstract

A system for performing an end-to-side vascular anastomosis, including an anastomosis device, an application instrument and methods for performing a vascular anastomosis. The system is applicable for performing an anastomosis between a vascular graft and the ascending aorta in coronary artery bypass surgery, particularly in port-access CABG surgery. A first aspect of the invention includes a vascular anastomosis staple. A first configuration has two parts: an anchor member, forming the attachment with the target vessel wall and a coupling member, forming the attachment with the bypass graft vessel. The anastomosis is completed by inserting the coupling member, with the graft vessel attached, into the anchor member. A second configuration combines the functions of the anchor member and the coupling member into a one-piece anastomosis staple. A second aspect of the invention includes an anastomotic fitting, having an inner flange over which the graft vessel is everted and an outer flange which contacts the exterior surface of the target vessel. A tailored amount of compression applied by the inner and outer flanges grips the target vessel wall and creates a leak-proof seal between the graft vessel and the target vessel. A third aspect of the invention has a flange to which the graft vessel attaches, by everting the graft vessel over the flange, and a plurality of staple-like members which attach the flange and the everted end of the graft vessel to the wall of the target vessel to form the anastomosis.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS
• This application is a continuation of co-pending application Ser. No. 09/166,338, which is a Divisional of Ser. No. 08/789,327, filed Jan. 23, 1997, which is a divisional of application Ser. No. 08/394,333, filed Feb. 24, 1995, now issued as U.S. Pat. No. 5,695,504. The complete disclosures of the forementioned related U.S. patent applications are hereby incorporated herein by reference for all purposes.[0001]
FIELD OF INVENTION
• The present invention relates generally to devices and methods for surgically performing an end-to-side anastomosis of hollow organs. More particularly, it relates to vascular anastomosis devices for joining the end of a graft vessel, such as a coronary bypass graft, to the side wall of a target vessel, such as the aorta or a coronary artery.[0002]
BACKGROUND OF THE INVENTION
• Anastomosis is the surgical joining of biological tissues, especially the joining of tubular organs to create an intercommunication between them. Vascular surgery often involves creating an anastomosis between blood vessels or between a blood vessel and a vascular graft to create or restore a blood flow path to essential tissues. Coronary artery bypass graft surgery (CABG) is a surgical procedure to restore blood flow to ischemic heart muscle whose blood supply has been compromised by occlusion or stenosis of one or more of the coronary arteries. One method for performing CABG surgery involves harvesting a saphenous vein or other venous or arterial conduit from elsewhere in the body, or using an artificial conduit, such as one made of Dacron or Goretex tubing, and connecting this conduit as a bypass graft from a viable artery, such as the aorta, to the coronary artery downstream of the blockage or narrowing. A graft with both the proximal and distal ends of the graft detached is known as a “free graft”. A second method involves rerouting a less essential artery, such as the internal mammary artery, from its native location so that it may be connected to the coronary artery downstream of the blockage. The proximal end of the graft vessel remains attached in its native position. This type of graft is known as a “pedicled graft”. In the first case, the bypass graft must be attached to the native arteries by an end-to-side anastomosis at both the proximal and distal ends of the graft. In the second technique at least one end-to-side anastomosis must be made at the distal end of the artery used for the bypass. In the description below we will refer to the anastomoses on a free graft as the proximal anastomosis and the distal anastomosis. A proximal anastomosis is an anastomosis on the end of the graft vessel connected to a source of blood (e.g. the aorta) and a distal anastomosis is an anastomosis on the end of the graft vessel connected to the destination of the blood flowing through it (e.g. a coronary artery). The anastomoses will also sometimes be called the first anastomosis or second anastomosis, which refers to the order in which the anastomoses are performed regardless of whether the anastomosis is on the proximal or distal end of the graft.[0003]
• At present, essentially all vascular anastomoses are performed by conventional hand suturing. Suturing the anastomoses is a time-consuming and difficult task, requiring much skill and practice on the part of the surgeon. It is important that each anastomosis provide a smooth, open flow path for the blood and that the attachment be completely free of leaks. A completely leak-free seal is not always achieved on the very first try. Consequently, there is a frequent need for resuturing of the anastomosis to close any leaks that are detected.[0004]
• The time consuming nature of hand sutured anastomoses is of special concern in CABG surgery for several reasons. Firstly, the patient is required to be supported on cardiopulmonary bypass (CPB) for most of the surgical procedure, the heart must be isolated from the systemic circulation (i.e. “cross-clamped”), and the heart must usually be stopped, typically by infusion of cold cardioplegia solution, so that the anastomosis site on the heart is still and blood-free during the suturing of the anastomosis. CPB, circulatory isolation and cardiac arrest are inherently very traumatic, and it has been found that the frequency of certain post-surgical complications varies directly with the duration for which the heart is under cardioplegic arrest (frequently referred to as the “crossclamp time”). Secondly, because of the high cost of cardiac operating room time. any prolongation of the surgical procedure can significantly increase the cost of the bypass operation to the hospital and to the patient. Thus, it is desirable to reduce the duration of the crossclamp time and of the entire surgery by expediting the anastomosis procedure without reducing the quality or effectiveness of the anastomoses.[0005]
• The already high degree of manual skill required for conventional manually sutured anastomoses is even more elevated for closed-chest or port-access thoracoscopic bypass surgery, a newly developed surgical procedure designed to reduce the morbidity of CABG surgery as compared to the standard open-chest CABG procedure. This procedure is more fully described in commonly-assigned, U.S. Pat. Nos. 5,452,733, issued Sep. 26, 1995 and 5,735,290, issued Apr. 7, 1998, the complete disclosures of which are hereby incorporated by reference. In the closed-chest procedure, surgical access to the heart is made through narrow access ports made in the intercostal spaces of the patient's chest, and the procedure is performed under thoracoscopic observation. Because the patient's chest is not opened, the suturing of the anastomoses must be performed at some distance, using elongated instruments positioned through the access ports for approximating the tissues and for holding and manipulating the needles and sutures used to make the anastomoses. This requires even greater manual skill than the already difficult procedure of suturing anastomoses during open-chest CABG surgery.[0006]
• In order to reduce the difficulty of creating the vascular anastomoses during either open or closed-chest CABG surgery, it would be desirable to provide a rapid means for making a reliable end-to-side anastomosis between a bypass graft or artery and the aorta or the native vessels of the heart. A first approach to expediting and improving anastomosis procedures has been through stapling technology. Stapling technology has been successfully employed in many different areas of surgery for making tissue attachments faster and more reliably. The greatest progress in stapling technology has been in the area of gastrointestinal surgery. Various surgical stapling instruments have been developed for end-to-end, side-to-side, and end-to-side anastomoses of hollow or tubular organs, such as the bowel. These instruments, unfortunately, are not easily adaptable for use in creating vascular anastomoses. This is partially due to the difficulty in miniaturizing the instruments to make them suitable for smaller organs such as blood vessels. Possibly even more important is the necessity of providing a smooth, open flow path for the blood. Known gastrointestinal stapling instruments for end-to-side or end-to-end anastomosis of tubular organs are designed to create an inverted anastomosis, that is, one where the tissue folds inward into the lumen of the organ that is being attached. This is acceptable in gastrointestinal surgery, where it is most important to approximate the outer layers of the intestinal tract (the serosa). This is the tissue which grows together to form a strong, permanent connection. However, in vascular surgery this geometry is unacceptable for several reasons. Firstly, the inverted vessel walls would cause a disruption in the blood flow. This could cause decreased flow and ischemia downstream of the disruption, or, worse yet, the flow disruption or eddies created could become a locus for thrombosis which could shed emboli or occlude the vessel at the anastomosis site. Secondly, unlike the intestinal tract, the outer surfaces of the blood vessels (the adventitia) will not grow together when approximated. The sutures, staples, or other joining device may therefore be needed permanently to maintain the structural integrity of the vascular anastomosis. Thirdly, to establish a permanent, nonthrombogenic vessel, the innermost layer (the endothelium) should grow together for a continuous, uninterrupted lining of the entire vessel. Thus, it would be preferable to have a stapling instrument that would create vascular anastomoses that are everted, that is folded outward, or which create direct edge-to-edge coaptation without inversion.[0007]
• At least one stapling instrument has been applied to performing vascular anastomoses during CABG surgery. This device, first adapted for use in CABG surgery by Dr. Vasilii I. Kolesov and later refined by Dr. Evgenii V. Kolesov (U.S. Pat. No. 4,350,160), was used to create an end-to-end anastomosis between the internal mammary artery (IMA) or a vein graft and one of the coronary arteries, primarily the left anterior descending coronary artery (LAD). Because the device could only perform end-to-end anastomoses, the coronary artery first had to be severed and dissected from the surrounding myocardium, and the exposed end everted for attachment. This technique limited the indications of the device to cases where the coronary artery was totally occluded, and therefore there was no loss of blood flow by completely severing the coronary artery downstream of the blockage to make the anastomosis. Consequently, this device is not applicable where the coronary artery is only partially occluded and is not at all applicable to making the proximal side-to-end anastomosis between a bypass graft and the aorta.[0008]
• One attempt to provide a vascular stapling device for end-to-side vascular anastomoses is described in U.S. Pat. No. 5,234,447, granted to Kaster et al. for a Side-to-end Vascular Anastomotic Staple Apparatus. Kaster et al. provide a ring-shaped staple with staple legs extending from the proximal and distal ends of the ring to join two blood vessels together in an end-to-side anastomosis. However, this device falls short of fulfilling the desired objectives of the present invention. Specifically, Kaster does not provide a complete system for quickly and automatically performing an anastomosis. The method of applying the anastomosis staple disclosed by Kaster involves a great deal of manual manipulation of the staple, using hand operated tools to individually deform the distal tines of the staple after the graft has been attached and before it is inserted into the opening made in the aortic wall. One of the more difficult maneuvers in applying the Kaster staple involves carefully everting the graft vessel over the sharpened ends of the staple legs, then piercing the everted edge of the vessel with the staple legs. Experimental attempts to apply this technique have proven to be very problematic because of difficulty in manipulating the graft vessel and the potential for damage to the graft vessel wall. For speed, reliability and convenience, it is preferable to avoid the need for complex maneuvers while performing the anastomosis. Further bending operations must then be performed on the staple legs. Once the distal tines of the staple have been deformed, it may be difficult to insert the staple through the aortotomy opening. Another disadvantage of the Kaster device is that the distal tines of the staple pierce the wall of the graft vessel at the point where it is everted over the staple. Piercing the wall of the graft vessel potentially invites leaking of the anastomosis and may compromise the structural integrity of the graft vessel wall, serving as a locus for a dissection or even a tear which could lead to catastrophic failure. Because the Kaster staple legs only apply pressure to the anastomosis at selected points, there is a potential for leaks between the staple legs. The distal tines of the staple are also exposed to the blood flow path at the anastomotic site where it is most critical to avoid the potential for thrombosis. There is also the potential that exposure of the medial layers of the graft vessel where the staple pierces the wall could be a site for the onset of intimal hyperplasia, which would compromise the long-term patency of the graft. Because of these potential drawbacks, it is desirable to make the attachment to the graft vessel as atraumatic to the vessel wall as possible and to eliminate as much as possible the exposure of any foreign materials or any vessel layers other than a smooth uninterrupted intimal layer within the anastomosis site or within the graft vessel lumen.[0009]
• A second approach to expediting and improving anastomosis procedures is through the use of anastomotic fittings for joining blood vessels together. One attempt to provide a vascular anastomotic fitting device for end-to-side vascular anastomoses is described in U.S. Pat. No. 4,366,819, granted to Kaster for an Anastomotic Fitting. This device is a four-part anastomotic fitting having a tubular member over which the graft vessel is everted, a ring flange which engages the aortic wall from within the aortic lumen, and a fixation ring and a locking ring which engage the exterior of the aortic wall. Another similar Anastomotic Fitting is described in U.S. Pat. No. 4,368,736, also granted to Kaster. This device is a tubular fitting with a flanged distal end that fastens to the aortic wall with an attachment ring, and a proximal end with a graft fixation collar for attaching to the graft vessel. These devices have a number of drawbacks that the present invention seeks to overcome. Firstly, the anastomotic fittings described expose the foreign material of the anastomotic device to the blood flow path within the arteries. This is undesirable because foreign materials within the blood flow path can have a tendency to cause hemolysis, platelet deposition and thrombosis. Immune responses to foreign material, such as rejection of the foreign material or auto-immune responses triggered by the presence of foreign material, tend to be stronger when the material is exposed to the bloodstream. As such, it is preferable that as much as possible of the interior surfaces of an anastomotic fitting that will be exposed to the blood flow path be covered with vascular tissue, either from the target vessel or from the graft vessel, so that a smooth, continuous, hemocompatible endothelial layer will be presented to the bloodstream. The anastomotic fitting described by Kaster in the '819 patent also has the potential drawback that the spikes that hold the graft vessel onto the anastomotic fitting are very close to the blood flow path, potentially causing trauma to the blood vessel that could lead to leaks in the anastomosis or compromise of the mechanical integrity of the vessels. Consequently, it is desirable to provide an anastomosis fitting that is as atraumatic to the graft vessel as possible. Any sharp features such as attachment spikes should be placed as far away from the blood flow path and the anastomosis site as possible so that there is no compromise of the anastomosis seal or the structural integrity of the vessels.[0010]
• Another device, the 3M-Unilink device for end-to-end anastomosis (U.S. Pat. Nos. 4,624,257; 4,917,090; 4,917,091) is designed for use in microsurgery, such as for reattaching vessels severed in accidents. This device provides an anastomosis clamp that has two eversion rings which are locked together by a series of impaling spikes on their opposing faces. However, this device is awkward for use in end-to-side anastomosis and tends to deform the target vessel; therefore it is not currently used in CABG surgery. Due to the delicate process needed to insert the vessels into the device, it would also be unsuitable for port-access surgery.[0011]
• In order to solve these and other problems, it is desirable to provide an anastomosis device which performs an end-to-side anastomosis between blood vessels or other hollow organs and vessels. It is also desirable to provide an anastomosis device which minimizes the trauma to the blood vessels while performing the anastomosis, which minimizes the amount of foreign materials exposed to the blood flow path within the blood vessels and which avoids leakage problems, and which promotes rapid endothelialization and healing. Further, it would be desirable to provide such a device which could be used in port-access CABG surgery. Whether it is used with open-chest or closed-chest surgical techniques, it is also desirable that the invention provide a complete system for quickly and automatically performing an anastomosis with a minimal amount of manual manipulation.[0012]
SUMMARY OF THE INVENTION
• n keeping with the foregoing discussion, the present invention provides an anastomosis system for quickly and reliably performing an end-to-side vascular anastomosis. The anastomosis system includes an anastomosis device, an application instrument and methods for their use in performing an end-to-side vascular anastomosis. The system is especially useful for performing an anastomosis between a vascular graft and the wall of the ascending aorta in CABG surgery particularly in port-access CABG surgery. One desirable attribute of the anastomosis system is that the system should be as atraumatic as possible to the graft vessel in creating the anastomosis. Another desirable attribute of the anastomosis system is that the anastomosis device should minimize the amount of foreign material exposed to the blood flow path in the completed anastomosis. The anastomosis device of the system has a generally tubular or ring-shaped body having a proximal end and a distal end. An orifice or internal lumen in the body allows the graft vessel to pass through the device from the proximal end to the distal end. The body of the device has an attachment means at the distal end for attachment to the graft vessel, generally by everting the graft vessel over the attachment means. Means are provided for attaching the device and the graft vessel to the wall of the target vessel. Different embodiments of the anastomosis device are presented which vary in the form of the means used for attaching to the graft vessel and the target vessel.[0013]
• A first aspect of the present invention takes the form of a vascular anastomosis staple device which may be used as part of an overall anastomosis stapling system and method designed to efficiently and reliably perform an end-to-side anastomosis between a graft vessel and the wall of a target vessel. The anastomosis staple device forms an atraumatic attachment to the end of the graft vessel so that only a smooth uninterrupted layer of intimal cells is exposed at the anastomosis site or within the graft vessel lumen. The anastomosis staple device creates a firm, reliable attachment between the graft vessel and the target vessel wall, with a tailored amount of tissue compression applied at the anastomosis site to form a leak-proof joint between the graft vessel and the target vessel wall. The anastomosis stapling system is designed to combine the various functions of graft vessel preparation, target vessel preparation, vessel approximation and anastomosis stapling into an integrated system of instruments so that the anastomosis can be performed efficiently with a minimum of manual manipulation of the vessels or the instruments involved. Different embodiments of the anastomosis stapling system are provided to meet the needs of performing either a first anastomosis or a second anastomosis of a bypass procedure. The anastomosis stapling system is configured to be adaptable for closed-chest or port-access CABG surgery or for more conventional open-chest CABG surgery.[0014]
• In one preferred configuration of the invention, the anastomosis staple device consists of two parts: an anchor member and a coupling member. The anchor member forms the attachment with the target vessel wall. The coupling member separately forms the attachment with the bypass graft vessel. The complete anastomosis is created when the coupling member, with the graft vessel attached, is inserted into the anchor member. In a second preferred configuration of the invention, the anastomosis staple device combines the functions of the anchor member and the coupling member into a simple member. A one-piece anastomosis staple device attaches to both the target vessel wall and the graft vessel to form a complete end-to-side anastomosis. In all embodiments of the anastomosis staple device, certain desirable aspects are maintained, specifically the atraumatic attachment of the device to the graft vessel and the rapid, reliable formation of the anastomosis, as well as the adaptability of the staple device to port-access CABG surgery.[0015]
• A second aspect of the present invention takes the form of an anastomotic fitting for attaching the end of a graft vessel to an opening formed in the side wall of a target vessel. The anastomotic fitting has an inner flange which provides an atraumatic attachment for the everted end of a graft vessel. The inner flange is configured so that, wherever possible, a smooth, continuous, uninterrupted layer of intimal tissue lines the graft vessel, the target vessel and the anastomotic site, with as little foreign material as possible exposed to the blood flow path. The outer flange contacts the exterior surface of the target vessel. A locking means, which may be part of the outer flange, locks the outer flange in a fixed position relative to the inner flange. The inner flange, in combination with the outer flange, provides a firm attachment to the target vessel wall. A tailored amount of compression applied by the inner and outer flanges grips the target vessel wall and creates a leak-proof seal between the graft vessel and the target vessel. Optionally, attachment spikes on the surfaces of either the inner or the outer flange provide additional grip on the graft vessel and/or the target vessel. The attachment spikes are isolated from the blood flow lumens of the graft vessel and the target vessel so that they do not compromise the anastomotic seal or the structural integrity of the anastomotic attachment.[0016]
• In a first representative embodiment, the anastomotic fitting is made up of two coacting parts: a) a tubular inner sleeve, which has an internal lumen of sufficient size to accommodate the external diameter of the graft vessel and an inner flange which is attached at the distal end of the inner sleeve, and b) an outer flange which has a central orifice that is sized to fit over the exterior of the inner sleeve. An adjustable locking mechanism holds the outer flange on the inner sleeve at a selected position to create a tailored degree of tissue compression at the anastomotic site.[0017]
• The anastomosis procedure is performed by passing the end of the graft vessel through the inner lumen of the inner sleeve until the end of the vessel extends a short distance from the distal end of the sleeve. The end of the graft vessel is then everted over the inner flange of the fitting to form an atraumatic attachment. A loop of suture or spikes on the outside of the inner sleeve or flange may be added to help retain the graft vessel in its everted position. The inner flange and the everted end of the graft vessel are then passed through an opening that has previously been made in the wall of the target vessel with an instrument such as an aortic punch. The opening must stretch slightly to allow the inner flange to pass through. The elastic recovery of the target vessel wall around the opening helps to create an anastomotic seal by contracting around the inner sleeve and the everted graft vessel wall. The outer flange is then slid onto the proximal end of the inner sleeve. If the anastomosis being performed is the first anastomosis on a free graft, such as a saphenous vein graft, then the outer flange can be slid over the graft vessel from the free end. If the other end of the graft vessel is not free, such as when performing the second anastomosis of a free graft or a distal anastomosis on a pedicled graft like the IMA, then the outer flange should be back loaded onto the graft vessel or preloaded onto the proximal end of the inner sleeve before the end of the graft vessel is attached to the inner flange of the fitting. The outer flange is slid down the inner sleeve until it contacts the exterior wall of the target vessel. A tailored amount of compression is applied to the anastomosis and the locking mechanism is engaged to complete the anastomosis.[0018]
• A second representative embodiment of the anastomotic fitting has an expanding inner flange which facilitates the atraumatic attachment of the graft vessel to the fitting and makes it easier to pass the inner flange and the everted graft vessel through the opening in the target vessel wall. The graft vessel is passed through an internal lumen of an inner sleeve which has the expandable inner flange attached at its distal end. The end of the graft vessel is everted over the unexpanded inner flange. The inner flange and the everted end of the graft vessel are passed through the opening in the target vessel wall. Once the inner flange of the fitting is in the lumen of the target vessel, it is expanded to a diameter which is significantly larger than the opening in the target vessel wall. Then an outer flange is applied and locked into a selected position on the inner sleeve as described above to complete the anastomosis.[0019]
• Different mechanisms are disclosed to accomplish the expansion of the inner flange. In a first variant of the expanding inner flange, the flange and a portion of the inner sleeve are slotted to create multiple fingers which are initially collapsed inward toward the center of the sleeve. A second inner sleeve is slidably received within the slotted inner sleeve. The graft vessel is inserted through the internal lumen of both sleeves and everted over the collapsed fingers of the flange. The collapsed flange is inserted through the opening in the target vessel. Then, the second inner sleeve is slid distally within the slotted inner sleeve. The second inner sleeve forces the fingers outward, expanding the flange within the target vessel. The anastomosis is completed by applying the outer flange to the fitting as described above.[0020]
• A second variant of the expanding inner flange has a slotted inner sleeve with multiple fingers that are oriented essentially longitudinally to the inner sleeve. Each of the fingers has a bend in it to predispose it to bend outward at the middle when under longitudinal compression. A tubular forming tool slidably received within the slotted sleeve is crenellated with multiple radially extending tabs. The radially extending tabs engage the distal ends of the fingers of the slotted inner sleeve. The anastomosis is performed by passing the graft vessel through the internal lumen of the fitting and everting it over the fingers. If desired, a loop of suture can be used to hold the everted vessel in place. The fingers of the fitting, and the everted end of the graft vessel are inserted through an opening in the target vessel wall. When the tubular forming tool is slid proximally with respect to the slotted inner sleeve, the radially extending tabs bear against the distal ends of the fingers, compressing them longitudinally. The fingers bow outward, folding at the bend to expand and create an inner flange which engages the inner surface of the target vessel wall. In a preferred embodiment of this variation, the slotted inner sleeve has a proximal collar which captures the outer flange of the fitting so that the outer flange is applied simultaneously with the expansion of the inner flange. After the inner flange has been expanded, the tubular forming tool can be removed by rotating it with respect to the slotted inner sleeve so that the tabs align with the slots allowing it to be withdrawn from the fitting. This reduces the mass of foreign material that is left as an implant at the anastomotic site.[0021]
• A third representative embodiment is a one-piece anastomotic fitting with an inner sleeve that is integrally attached to a fixed inner flange and to a deformable outer flange. The anastomosis is performed by passing the graft vessel through the internal lumen of the inner sleeve and everting it over the inner flange. The inner flange and the everted end of the graft vessel are inserted through an opening in the wall of the target vessel. Then, the outer flange is deformed against the exterior surface of the target vessel wall with a tailored degree of tissue compression to complete the anastomosis. Two variants of the deformable outer flange are disclosed. The first variant has an outer flange that is divided into flange segments. The flange segments are attached to the inner sleeve by deformable hinges. The second variant has an outer flange in the form of a deformable hollow body. The hollow body is deformed against the exterior surface of the target vessel to complete the anastomosis.[0022]
• The vascular anastomotic fitting is also part of a complete anastomosis system which includes instruments for applying the anastomosis fitting in a rapid, efficient and reliable manner to expedite the anastomosis process and to reduce the amount of manual manipulation necessary to perform the anastomosis. The application instrument has an elongated body with means at the distal end for grasping the anastomosis fitting and inserting the fitting into the chest cavity of a patient through an access port. The instrument includes an actuating means for deploying the inner and/or outer flange of the fitting to create the anastomosis. Variants of the instrument are specially adapted for each different embodiment and subvariation of the anastomosis fitting.[0023]
• A third approach to expediting and improving anastomosis procedures used by the present invention combines the advantages of surgical stapling technology with other advantages of anastomotic fittings. Surgical stapling technology has the potential to improve anastomosis procedures over hand suturing techniques by decreasing the difficulty and complexity of the manipulations necessary and by increasing the speed and reliability of creating the anastomosis. The Kaster vascular staple in U.S. Pat. No. 5,234,447 overcomes one of the major limitations of the previous Kolesov stapling device by allowing a stapled end-to-side anastomosis. This device, however, requires many delicate manual manipulations of the graft vessel and the staple while performing the anastomosis. This device therefore does not take full advantage of the time saving potential usually associated with stapling techniques.[0024]
• The present invention attempts to marry the advantages of stapling approaches and anastomotic fitting approaches while carefully avoiding their potential drawbacks. As such, the present invention takes full advantage of the speed and reliability of stapling techniques, avoiding inasmuch as possible the need for complex manual manipulations. The invention also profits from the advantages of anastomotic fittings by providing a ring or flange that exerts even pressure around the anastomotic interface to eliminate potential leaks between the stapled attachments. The ring or flange also serves as a stent or support for the anastomosis site to prevent acute or long-term closure of the anastomosis. Inasmuch as possible the bulk of the fitting is kept on the exterior of the anastomosis so as to eliminate exposed foreign material in the bloodstream of the graft vessel or the target vessel. In most cases, only the narrow staple legs penetrate the anastomosis site, so that an absolute minimum of foreign material is exposed to the blood flow path, on the same order as the mass of suture exposed in a standard sutured anastomosis. The attachment technique for the anastomosis device eliminates the need to evert the graft vessel over a complex, irregular or sharp object such as the sharpened ends of the staple legs. Instead, a smooth ring or flange surface is provided for everting the graft vessel without damage or undue complication. The staple legs are separate or recessed within the flange to avoid potential damage to the graft vessel while attaching it to the device.[0025]
• In a third aspect, the present invention takes the form of an anastomosis device which has a ring or flange to which the graft vessel attaches, typically by everting the graft vessel over the distal end of the ring. The ring or flange resides on the exterior of the graft vessel so that it does not contact the blood flow path. A plurality of staple-like members attach the ring and the everted end of the graft vessel to the wall of the target vessel, which may be the aorta, a coronary artery or other vessel. An opening is created in the target vessel wall with an aortic punch or similar instrument to allow the target vessel lumen to communicate with the graft vessel lumen. The opening in the target vessel wall can be made before or after the device has been attached, depending on the application technique employed. In most of the examples disclosed, the staple members pierce the everted wall of the graft vessel and the wall of the target vessel to hold the two vessels together. Alternatively, the staple members may enter the lumen of the target vessel through the opening in the wall and then pierce the wall of the target vessel in the reverse direction. This variation pins together the vascular layers in the target vessel at the cut edge, potentially reducing the incidence of hemodynamically generated dissections in the wall of the target vessel.[0026]
• Various configurations of the invention are disclosed which all exhibit the unifying characteristics of a cooperating ring or flange and a plurality of staple members. A first exemplary embodiment includes a ring-like fastening flange with deformable staple members for attaching the flange. A specially adapted staple applying device which operates through the lumen of the graft vessel is used to deform the staples to complete the anastomosis. A second embodiment includes a ring-like fastening flange with preformed, spring-like staple members. The elastic memory of the spring-like staple members holds the anastomosis tightly together. A family of embodiments includes a tubular fastening flange with U-shaped staple members and a locking means for fastening the staple members to complete the anastomosis. Another family of embodiments includes one or more ring-shaped fastening flanges with integrally formed staple members. Another family of embodiments includes a ring-like fastening flange with self-deploying staple members made of a superelastic metal alloy or a thermally activated shape-memory alloy. A specially adapted staple applying device deploys the superelastic staple members. The specially adapted staple applying device together with the anastomosis device itself forms a total anastomosis system that is adaptable or either conventional open-chest CABG surgery or port-access CABG surgery.[0027]
• Catheter devices are described which can be used as part of the total anastomosis system for isolating a portion of the target artery to facilitate performing the anastomosis procedure. One catheter device is configured to isolate a portion of the ascending aorta wall without occluding blood flow through the lumen of the aorta. A second catheter device is configured to be delivered by a transluminal approach for isolating a portion of a coronary artery during the anastomosis procedure. A third catheter device is configured to be delivered through the lumen of the graft vessel for isolating a portion of a coronary artery during the anastomosis procedure.[0028]
BRIEF DESCRIPTION OF THE DRAWINGS
• FIG. 1 is a perspective view of the anchor member and the coupling member of a two-piece embodiment of the anastomosis staple device of the present invention.[0029]
• FIG. 2 is a perspective view of a staple applier system for applying the anastomosis staple device of FIG. 1.[0030]
• FIG. 3 is a perspective view of the distal end of the staple applier system of FIG. 2 showing the stapling mechanism and the vessel punch mechanism along with the anchor member of the two-piece anastomosis staple device of FIG. 1.[0031]
• FIG. 4 is a cross sectional view of the distal ends of the stapling mechanism and the vessel punch mechanism of the staple applier system of FIG. 2 along with the anchor member of the two-piece anastomosis staple device of FIG. 1.[0032]
• FIGS.[0033]5A-5G are side cross section view showing the sequence of operations for creating an end-to-side anastomosis with the two-piece anastomosis staple device of FIG. 1.
• FIGS. 6A is a perspective view of the graft insertion tool of the anastomosis staple applier system of FIG. 2 prepared for insertion of the bypass graft with the coupling member of the two-piece anastomosis staple device.[0034]
• FIGS.[0035]6B-6C are side cross section and perspective views, respectively, of the distal end of the graft insertion tool of FIG. 6A.
• FIGS.[0036]7A-7C are perspective, bottom end, and side cross section views, respectively showing a variation of the graft insertion tool prepared for creating a second anastomosis of the bypass graft using the two-piece anastomosis staple device of FIG. 1
• FIGS.[0037]8A-8G are side views of various configurations of the attachment legs of the anchor member of FIG. 1 which allow for tailored amounts of tissue compression at the anastomosis site.
• FIG. 9 is a perspective view of a one-piece embodiment of the anastomosis staple device of the present invention.[0038]
• FIG. 10 is a cross sectional view of the one-piece anastomosis staple device of FIG. 9 being actuated to form an end-to-side anastomosis.[0039]
• FIG. 11 is a cross sectional view of a one-piece anastomosis staple device with extended first segments on the staple legs.[0040]
• FIG. 12 is a cross sectional view of a one-piece anastomosis staple device with secondary pivot points on the staple legs to create radial tissue compression.[0041]
• FIG. 13 is a side cross sectional view of a staple applying tool for creating an end-to-side anastomosis using the one-piece anastomosis staple device of FIG. 9.[0042]
• FIG. 14 is a cross sectional view of the distal end of the staple applying tool of FIG. 13 holding the one-piece anastomosis staple device of FIG. 9 with a graft vessel attached thereto.[0043]
• FIGS. 15A is a detail drawing of the female bayonet connector on the distal end of the anastomosis staple applying tool of FIG. 13.[0044]
• FIG. 15B is an end view of the male bayonet connector on the proximal end of the one-piece anastomosis staple device of FIG. 9.[0045]
• FIG. 16 is a cross sectional schematic of another alternate embodiment of the one-piece anastomosis staple device being actuated to form an end-to-side anastomosis.[0046]
• FIG. 17A-[0047]17B are a perspective views of a first alternate construction of the two-piece anastomosis staple device of FIG. 1.
• FIG. 17C is a cross section view of the anchor member of the anastomosis staple device of FIG. 17A attached to the wall of a target vessel.[0048]
• FIG. 17D is a cross section view of a completed anastomosis using the device of FIG. 17A-[0049]17B.
• FIGS.[0050]18A-18F show a second alternate construction of the two-piece anastomosis staple device of FIG. 1.
• FIG. 19A-[0051]19B shows a third alternate construction of the two-piece anastomosis staple device of FIG. 1.
• FIG. 20 is a side cross section view of a fourth alternate construction of the two-piece anastomosis staple device of FIG. 1.[0052]
• FIGS.[0053]21A-21C are side partial cross section views of a first embodiment of an anastomotic fitting according to the invention.
• FIGS.[0054]22A-22C are side cross section views of an anastomosis fitting which is a variation of the embodiment of FIGS.21A-21C.
• FIG. 22D is a proximal end view of the anastomosis fitting of FIG. 22C.[0055]
• FIGS.[0056]23A-23D are side cross section views of another variant of the embodiment of the anastomosis fitting of FIGS.21A-21C and FIGS.22A-22C.
• FIGS.[0057]24A-24B are side cross section views of a second embodiment of the anastomotic fitting of the invention having an expanding inner flange.
• FIGS. 24C and 24D are distal end views of the expanding inner flange in the collapsed position and the expanded position, respectively.[0058]
• FIGS.[0059]25A-25H show a second variant of the anastomotic fitting with an expanding inner flange is shown in FIGS.24A-24D.
• FIGS.[0060]26A-261 show a third embodiment which is a one-piece anastomotic fitting with a deformable outer flange.
• FIGS.[0061]27A-27D show a second variant of the anastomotic fitting with a deformable outer flange.
• FIGS.[0062]28A-28I show a third variant of the anastomotic fitting with a deformable outer flange.
• FIGS.[0063]29A-29C show an embodiment of the anastomotic fitting having a secondary flange washer which attaches to the inner flange.
• FIGS.[0064]30A-30K show an embodiment of the anastomotic fitting combining deformable inner staple members and an outer flange.
• FIGS.[0065]31A-31F show a first embodiment of an anastomotic device combining a fastening flange with a plurality of staple members.
• FIGS.[0066]32A-32F show an anastomosis device using preformed spring-like fastening staple members.
• FIGS.[0067]33A-33D show an anastomosis device using S-shaped staple members that pierce the interior wall of the target vessel.
• FIGS.[0068]34A-34D show an anastomosis device using S-shaped staple members that do not pierce the interior wall of the target vessel.
• FIGS.[0069]35A-35F show an anastomosis device using U-shaped staple members with barbed points.
• FIGS.[0070]36A-36C show an anastomosis device using U-shaped staple members and a locking collar.
• FIGS.[0071]37A-37C show a second anastomosis device using U-shaped staple members and a locking collar.
• FIGS.[0072]38A-38C show a one-piece anastomosis device with integral staple members.
• FIGS.[0073]39A-39C show a second one-piece anastomosis device with integral staple members.
• FIGS.[0074]40A-40D show a two-piece anastomosis device having two concentric ring flanges with integral staple members.
• FIGS.[0075]41A-41E show an anastomosis device having a fastening flange and a plurality of individual staple members.
• FIGS.[0076]42A-42D illustrate a one-piece embodiment of the anastomosis device with a fastening flange and attached staple members.
• FIGS.[0077]43A-43B show the fastening flange of an anastomosis device using preformed superelastic alloy staple members in a top view and a side view, respectively.
• FIGS.[0078]44A-44B show the superelastic alloy staple members of the anastomosis device in a front view and a side view, respectively.
• FIGS.[0079]45A-45E show the sequence of operations of an application instrument for the anastomosis device of FIGS.43A-43B and FIGS.44A-44B.
• FIGS.[0080]46A-46D illustrate a second embodiment of the anastomosis system using an anastomosis device with an inner fastening flange, an outer flange and staple members made of a superelastic alloy.
• FIGS.[0081]47A-47B show an anastomosis staple device combining a fastening flange with precurved inner staple members of a highly resilient material and deformable outer attachment legs in an undeployed state.
• FIGS.[0082]48A-48B show the anastomosis staple device of FIGS.47A-47B in a deployed state.
• FIGS.[0083]49A-49C show the sequence of operations for deploying the anastomosis staple device of FIGS.47A-47B.
• FIGS.[0084]50A-50B show a staple application instrument for applying the anastomosis staple devices of FIGS.47A-47B.
• FIG. 51 shows a combination strain relief and compliance mismatch transition sleeve for use with any of the anastomosis devices of the present invention.[0085]
• FIG. 52 shows a dual-balloon perfusion endoaortic clamp catheter for isolating a portion of the aortic wall while performing a proximal anastomosis in CABG surgery.[0086]
• FIG. 53 shows a dual-balloon coronary isolation and perfusion catheter for use in performing a distal anastomosis in CABG surgery.[0087]
• FIG. 54 shows a T-shaped dual-balloon coronary isolation and perfusion catheter for use in performing a distal anastomosis in CABG surgery.[0088]
• FIGS. 55, 56,[0089]57 show the sequence of operations for creating an end-to-side anastomosis during port-access CABG surgery using the anastomosis stapling system of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
• The invention will be now be described in detail with reference to the accompanying drawings. The detailed description describes the invention in relation to a proximal anastomosis during CABG surgery for joining the proximal end of the bypass graft to the aortic wall. This example is given by way of illustration only and is in no way meant to be limiting. Those skilled in the art will recognize that the anastomosis staple device and anastomosis stapling system of the present invention are readily adaptable for end-to-side connections of distal anastomoses (i.e. graft to coronary artery anastomoses) during CABG surgervy as well as for use on other blood vessels and other tubular organs within the body. For consistency and convenience, throughout the description the two ends of the anastomosis staple are referred to as the proximal and distal ends of the staple, the distal end of the staple being the end which is closest to the inner lumen of the target vessel and the proximal end being the free end which is farthest from the inner lumen of the target vessel.[0090]
• FIG. 1 is a perspective drawing of a first embodiment of the anastomosis staple device of a first aspect of the present invention. The anastomosis[0091]staple device100 consists of two parts: ananchor member101, and acoupling member102. Theanchor member101 forms the attachment to the exterior surface of the wall of a target vessel such as the aorta. Thecoupling member102 forms the attachment to the bypass graft vessel. When the coupling member is joined to the anchor member, as shown by the dottedlines103, it forms a complete anastomosis.
• The[0092]anchor member101 has a ring-shapedframe104 which is configured to encircle an opening in the wall of a target vessel, such as the aorta. The ring-shapedframe104 has a plurality ofattachment legs105, preferably six to twelve, circumferentially spaced around theframe104 and projecting from thedistal end106 of the ring. Theanchor member101 is preferably made of stainless steel or a titanium alloy for strength, biocompatibility and absence of MRI interference. The ring-shapedframe104 and theattachment legs105 preferably have a wall thickness of approximately 0.2 to 0.6 mm. The width of each of theattachment legs105 is preferably between 0.5 and 2.0 mm. Theattachment legs105 could also be made with a round cross section to eliminate sharp edges which might propagate tears. The precise dimensions of theattachment legs105 would be a compromise between making the legs rigid enough to pierce the wall of the target vessel without undue deformation, yet flexible enough to permit the stapling mechanism to deform the attachment legs after they have pierced the target vessel wall to hold the anchor member in place. These dimensions may vary depending on which vessel is chosen as the target vessel for the anastomosis.
• The[0093]attachment legs105 extend first radially outward from thering104, then there is atransition curve107, after which thelegs105 extend axially away from thering104 in the distal direction. Thetransition curve107 in eachattachment leg105 is shaped so that theanchor member101 can be placed precisely on the target vessel wall, then affixed firmly in place with minimal displacement of theanchor member101 or distortion of the target vessel wall. This attachment process will be described more fully in the operational description below.
• The points of attachment between the[0094]attachment legs105 and the ring-shapedframe104 in this illustrative embodiment are all shown as being coplanar with one another. In other preferred embodiments, thedistal extremity106 of theanchor member101 may be contoured to match the curvature of the exterior surface of the target vessel. Thus, the points of attachment between theattachment legs105 and the ring shapedframe104 will be arranged on a cylindrically curved surface which intersects thering104 of theanchor member101 rather than a plane. This would be especially important when there is closer parity between the diameter of the graft vessel and the diameter of the target vessel, such as when performing a distal anastomosis between a venous or arterial graft and a coronary artery, because a planar arrangement of theattachment legs105 would not approximate the curvature of the target vessel wall as well as for a larger target vessel such as the aorta. In other alternate embodiments, the distal end of theanchor member106 and theattachment legs105 may be angled with respect to the ring-shapedframe104 to permit an angled takeoff of the graft vessel from the target vessel.
• One preferred configuration for the[0095]transition curve107 in theattachment legs105 is illustrated in FIG. 1. Thefirst segment108 of each attachment leg extends radially from the ring-shaped frame for a short distance. Thesecond segment109 of each leg angles proximally from the first segment at approximately 60° for a short distance. Then, thethird segment110 angles approximately 60° in the distal direction from thesecond segment109. The fourth segment111 extends in the distal direction from thethird segment110 so that the fourth segment111 extends axially away from the ring-shapedframe104 parallel to the central axis of thering104. The second109 and the third110 segments should be approximately equal in length to one another. The actual length of the second109 and third110 segments will be determined by the wall thickness of the target vessel. A typical length of 1.5-5 mm would be used for attachment to the wall of the aorta. The distal ends112 of theattachment legs105 are sharpened to easily penetrate the aortic wall.
• This illustrates just one[0096]preferred transition curve107 for theattachment legs105. Alternate transition curves107 for theattachment legs105 may include arc-shaped segments in place of some of the straight segments or may include a greater number of straight segments to approximate a smoother curve. When choosing alternate curves, it is important to preserve the axially extending final segment111 of the attachment legs in order to penetrate the target vessel wall. In addition, it is important to control the amount of distortion of the target vessel wall when theanchor member101 is attached. This is in contrast to many standard wound closure staples which deliberately bunch up the tissue when they are applied to create a closer approximation of the tissues being joined. This type of distortion may be counterproductive in attaching a graft vessel to the aortic wall because the wall may be too stiff to distort in this manner and the distortion might cause problems in creating a leak proof seal at the anastomosis. The anvil geometry of the stapling mechanism will also be important in determining the optimum geometry of the attachment legs.
• The amount of radial compression of the target vessel wall around the anastomosis can be tailored by the choice of the[0097]transition curve107 in theattachment legs105 of theanchor member101. Radial compression of the target vessel wall around the anastomosis helps to create and maintain an anastomotic seal between the target vessel and the graft vessel in the completed anastomosis. This is especially important when blood pressure is restored in the target vessel which will tend to stretch the target vessel wall and pull it away from the anastomosis. The radial compression by the attachment legs counteracts this expansion and maintains the anastomotic seal under pressure. FIG. 8A-8G show various other possible geometries for theattachment legs105 of theanchor member101 arranged according to the degree of tissue compression applied to the target vessel wall. FIG. 5A shows astaple attachment leg105 where thetransition curve107 consists of a straight second segment which extends upward at ninety degrees from the first radially extending segment. Thethird segment110 describes a 90° arc with a center of rotation at the transition point between the first108 and second109 segments. The fourth segment111 extends straight in an axial direction from thethird segment110. This embodiment of theattachment legs105 creates very little tissue compression when applied. The amount of tissue compression is indicated by the shaded region between the straight insertion path of the fourth segment111 and the final position of the actuated staple shown in phantom lines105. FIG. 8B shows atransition curve107 with an elliptically shapedsecond segment109 which smoothly evolves into an arc-shapedthird segment110 with a center of rotation at the transition point between the first108 and second109 segments. This embodiment creates a slightly greater degree of tissue compression. FIG. 8C shows an attachment leg geometry which is formed entirely of smooth curves so as to avoid any sharp bends in theattachment legs105, but which produces approximately the same tissue compression as the attachment leg of FIG. 8B. FIG. 8D shows atransition curve107 with a 30° arc-shapedsecond segment109 connecting to a 30° arc-shapedthird segment110 with a center of rotation at the transition point between the first108 and second109 segments. FIG. 8E shows a side view of the embodiment illustrated and described above in FIG. 1. Thesecond segment109 angles 60° upward from thefirst segment108. and thethird segment110 angles downward at 60° from thesecond segment109. This produces a selected degree of tissue compression when theattachment legs105 are actuated. FIG. 8F shows an attachment leg geometry which produces slightly greater tissue compression in the target vessel. The second109 and third110 segments of thetransition107 are smoothly blended together in a continuous semicircular arc. FIG. 8G shows an attachment leg geometry which produces even more tissue compression. Thesecond segment109 angles upward at 45° from thefirst segment108 and thethird segment110 angles downward from the second109 at a 90° angle. Many other attachment leg geometries may be tailored to produce the desired degree of tissue compression in the target vessel.
• The[0098]coupling member102, as seen in FIG. 1, has atubular body113 with apassage114 through it. The distal end of thecoupling102 has anatraumatic edge115 over which the graft vessel will be everted in forming the anastomosis. Theatraumatic edge115 is important to avoid piercing or damaging the vessel wall in the vicinity of the anastomosis which occurs with some prior art devices. Atraumatic attachment of the graft vessel to the coupling member helps to assure a reliable anastomotic seal between the graft vessel and the target vessel and reduces the likelihood of mechanical failure of the graft vessel wall due to punctures or tears in the wall. The exterior of thecoupling member102 is sized to fit into the interior of the ring-shapedframe104 of the anchor member with enough space between them to accommodate one wall thickness of the bypass graft. Thecoupling member102 is preferably made of stainless steel, a titanium alloy or plastic with a wall thickness of approximately 0.1 to 0.6 mm. The exterior of thecoupling member102 has exterior surface features116 which serve a dual purpose. The exterior surface features116 serve to hold the everted end of the bypass graft onto thecoupling member102, as well as to interlock thecoupling member102 with theanchor member101 to complete the anastomosis. Likewise, the interior of theanchor member101 is made with interior surface features117 which interact with the exterior surface features116 to create the interlock. The exterior surface features116 of thecoupling member102 could be in the form of bumps, pins, points, barbs, ridges, threads, holes or a combination of these features. The interior surface features117 of theanchor member101 would then be in the form of corresponding bumps, pins, points, barbs, ridges, threads or holes to lock the two parts together. It should be noted that, if pins, points, barbs or other piercing members are used as the interior117 orexterior116 surface features of the anastomosisstaple device100, these potentially traumatic features are located away from the everted edge of the graft vessel and outside of the lumens of the graft vessel and target vessel that will serve as the conduit of the bypass so as not to compromise the integrity of the anastomosis.
• In the embodiment illustrated, the[0099]coupling member102 is shown with bump-shaped exterior surface features117 that hold the everted graft vessel onto thecoupling member102 and interlock with a series ofcircumferential ridges116 within theanchor member101. Theinterior ridges116 of theanchor member101 permit a variable degree of engagement between thecoupling member102 and theanchor member101 to allow for different wall thicknesses of the target vessel and the graft vessel used in the anastomosis. The axial position of thecoupling member102 with respect to theanchor member101 can be varied to create the desired degree of axial tissue compression to assure an anastomotic seal despite variations in the vessel wall thicknesses.
• The complete anastomosis stapling system includes the anastomosis[0100]staple device100 and aninstrument118 for applying theanastomosis staple100. Theinstrument118 for applying the two-part anastomosis staple100 consists of three separate, but interacting, mechanisms: astapling mechanism119, avessel punch mechanism120, and agraft insertion tool121,122. Together with theanchor member101 and thecoupling member102, they comprise a complete system for performing an anastomosis. In FIG. 2, we can see two of these mechanisms, thestapling mechanism119 and thevessel punch mechanism120, assembled together with theanchor member101 of theanastomosis staple100, prepared for the first stage of the anastomosis procedure. The third mechanism, the graft insertion tool, is shown in twodifferent embodiments121,122 in FIGS.6A-6C and FIGS.7A-7C, respectively.
• The[0101]stapling mechanism119 and thevessel punch120 are shown assembled together in a perspective view in FIG. 2. Theanchor member101 of theanastomosis staple100 is held by thestaple retainer123 on the distal end of the stapling mechanism. This same assembly can be seen in cross section in the operational drawings5A-5C. The distal end of this assembly is shown in greater detail in cross section in FIG. 4. Thestapling mechanism119 has aninner tube124 and anouter tube125 which are threaded together at their distal ends. Theouter tube125 has ahandle126 at the proximal end and anannular staple driver127 at the distal end of the tube. Theinner tube124 has astaple retainer123 for holding theanchor member101 of theanastomosis staple100 on the distal end of the tube. Theinner tube124 has aninternal lumen128 of sufficient size to accommodate thevessel punch mechanism120 and thegraft insertion tool121, alternately. The proximal end of theinner tube124 has a pair of opposingslots129 on the inner surface that act as splines for engagement with a corresponding pair oflugs130,134 on the exterior of thevessel punch mechanism120 and on thegraft insertion tool121.
• The[0102]vessel punch mechanism120 is sized to fit through theinternal lumen128 of theinner tube124 of thestapling mechanism119. Thevessel punch mechanism120 has anouter tube131 and aninner drive member132 slidably received within the outer tube. The proximal end of theouter tube131 is attached to a T-shapedhandle133. Theouter tube131 has a pair oflugs130 near the proximal end which extend radially from the exterior of thetube131 to engage the opposingslots129 in theinner tube124 of thestapling mechanism119. The distal end of theouter tube131 tapers to form aneck135 which attaches to acutter anvil136. Thevessel punch cutter137 is a tubular member which slides telescopically on the distal end of theouter tube131 of thevessel punch120. Thedistal edge138 of thetubular cutter137 is sharpened with an approximatelyconical bevel138. Theouter tube131 of thevessel punch mechanism120 may include astep139 against which the cutter is located in the retracted position as in FIGS. 5A and 5B. Thetubular cutter137 is attached to the drive member by atransverse pin140 which extends through a pair of opposingslots141 in the distal end of theouter tube131. The proximal end of thedrive member132 is attached to anactuating plunger142 which extends proximally of the T-shapedhandle133.
• The[0103]vessel punch mechanism120 is actuated by pressing on theactuating plunger142 to move it with respect to the T-shapedhandle133. This linear motion is transferred to theinner drive member132 and then, in turn, to thetubular cutter137 by way of thetransverse pin140. Thetubular cutter137 slides forward until the inner lumen of thecutter137 slides over theanvil136 in a shearing action. There is a very tight clearance between the inner lumen of thecutter137 and the outer diameter of theanvil136. This tight clearance assures a cleanly cut hole through the vessel wall without ragged or torn edges. In FIG. 5C, thevessel punch mechanism120 is shown actuated to cut a hole through the aortic wall tissue.
• FIG. 3 is a large scale perspective detail drawing of the distal end of the[0104]vessel punch mechanism120 assembled with thestapling mechanism119. Theanchor member101 of theanastomosis staple100 is held by thestaple retainer123 on the distal end of theinner tube124 of thestapling mechanism119. The ring-shapedframe104 of theanchor member101 fits inside of acounterbore143 on the distal end of the inner tube, as can be seen in FIGS. 4 and 5A-5E. Theattachment legs105 of theanchor member101 are captured and held by the L-shapedgripping fingers144 which extend from the distal end of theinner tube124. There are an equal number ofgripping fingers144 on theinner tube124 as there areattachment legs105 on theanchor member101. Eachgripping finger144 has anaxial slot145 alongside of it which is at least as wide as theattachment legs105. Theaxial slot145 connects with atransverse slot146 in the side of eachgripping finger144. Theanchor member101 of theanastomosis staple100 is loaded onto thestaple retainer123 by aligning theattachment legs105 with the ends of theaxial slots145, pushing theattachment legs105 to the bottom of theaxial slots145, then turning theanchor member101 counterclockwise until theattachment legs105 enter thetransverse slots146 in the side of the grippingfingers144. Theanchor member101 can be secured in this position by rotating theouter tube124 of the stapling mechanism to advance it distally until thestaple driver127 contacts theattachment legs105 with enough force to hold theanchor member101 in place without deforming the legs. Alternatively, theinner tube124 of thestapling mechanism119 could be adapted to grip the ring-shapedelement104 of theanchor member101 directly.
• The T-shaped[0105]handle133 of thevessel punch mechanism120 also serves as the handle for theinner tube124 of thestapling mechanism119 at this stage of the procedure because thelugs130 on the exterior of the vessel punchouter tube131 engage theslots129 in the interior of the staplerinner tube124. Likewise, in the latter stages of the procedure, the T-shapedhandle133 of thegraft insertion tool121 can also serve as a handle for theinner tube124 of thestapling mechanism119 because thelugs134 of thegraft insertion tool121 engage theinner slots129 of the staplerinner tube124 in a similar fashion. Alternatively, theinner tube124 of the stapling mechanism may be supplied with a separate handle or knob of its own so the inner124 and outer125 tubes of the stapling mechanism can be rotated with respect to one another to operate the stapling mechanism when neither theaortic punch mechanism120 nor thegraft insertion tool121 is inserted into thestapling mechanism119.
• A first embodiment of the[0106]graft insertion tool121 and its relationship to thecoupling member102 of theanastomosis staple100 are shown in detail in FIGS.6A-6C. This embodiment of thegraft insertion tool121 may be used when theanastomosis staple100 is used to form the first anastomosis of the bypass procedure no matter whether the first anastomosis is the proximal or the distal anastomosis of the graft. To prepare the bypass graft for creating the anastomosis, thecoupling member102 is first loaded onto the distal end of thegraft insertion tool121. Ashoulder147 on thegraft insertion tool121 holds thecoupling member102 in the correct position, and a tight interference fit or a spring action prevents it from inadvertently falling off. Thegraft vessel148 is then loaded into theinternal lumen149 of thegraft insertion tool121. This can be done by tying a suture around the graft vessel on the end opposite to the end that will be anastomosed, passing the suture through theinternal lumen149 of thegraft insertion tool121, then drawing thegraft vessel148 into the lumen until theend192 of thegraft vessel148 to be anastomosed extends a short distance from the distal end of thegraft insertion tool121. Alternatively, a special tool, such as a narrow pair of endoscopic forceps or a nerve hook, may be used for grasping thegraft vessel148 and drawing it through thegraft insertion tool121. At this point, theend192 of thegraft vessel148 to be anastomosed is everted over the end of thegraft insertion tool121 and thecoupling member102, as shown in FIGS.6A-6C. The external surface features116 of thecoupling member102 serve to hold the graft vessel onto the exterior of thecoupling member102 in the everted position. The external surface features116 of the coupling member may at least partially penetrate the wall of thegraft vessel148 to provide greater holding force.
• With the[0107]anchor member101 loaded onto thestapling mechanism119 and thegraft vessel148 prepared by everting and attaching it to thecoupling member102 as described above, the device is ready to perform the end-to-side anastomosis, as illustrated in FIGS.5A-5G. Referring now to FIG. 5A, thestapling mechanism119 and thevessel punch mechanism120 are shown assembled together. Aslit150 is made in thetarget vessel wall150 with a scalpel or other sharp instrument, and theanvil136 of thevessel punch120 is inserted through theslit151 into the lumen of thetarget vessel150. Theanvil136 serves to center thestapling mechanism119 and theanchor member101 around the chosen attachment point on thetarget vessel150 where theslit151 is made. Thestapling mechanism119 is advanced over thevessel punch mechanism120 toward the wall of thetarget vessel150, as shown in FIG. 5B. A slight tension is maintained on the T-handle133 of thevessel punch mechanism120 so that theanvil136 supports the wall of thetarget vessel150 as theattachment legs105 of theanchor member101 contact and penetrate thetarget vessel wall150. The fourth segments111 of theattachment legs105 penetrate thetarget vessel wall150 in a linear path. Once the fourth segments111 of theattachment legs105 have traversed thetarget vessel wall150, theattachment legs105 are actuated, as shown in FIG. 5C. Theouter tube125 of thestapling mechanism119 is advanced over theinner tube124 by rotating thehandle126 of theouter tube125 with respect to the T-handle133 of thevessel punch mechanism120. This advances thestaple driver127 against theattachment legs105, deforming them into the position shown in FIG. 5C. After theattachment legs105 have been actuated, thetubular cutter137 of thevessel punch mechanism120 is advanced with respect to theanvil136, as shown in FIG. 5D, by pressing on theactuating plunger142 at the proximal end of thedrive member132. Thepunch mechanism120 creates anopening152 through thetarget vessel wall150. Thevessel punch mechanism120 with thetissue153 that was excised by the punch can now be withdrawn from theinner lumen128 of thestapling mechanism119, as shown in FIG. 5E, leaving theanchor member101 attached to thetarget vessel wall150 in alignment with theopening152 punched therein.
• The graft[0108]vessel insertion tool121 with theprepared graft vessel148 andcoupling member102 in place is inserted into theinner lumen128 of thestapling mechanism119 as shown in FIG. 5F. Thecoupling member102 is pressed into the ring-shapedframe104 of theanchor member101 and the exterior features116 on thecoupling member102 engage the interior features117 of the ring-shapedframe104 to hold thecoupling member102 and theanchor member101 together. Thestaple retainer123 of thestapling mechanism119 still has a firm grasp on theanchor member101 to provide support as thecoupling member102 is pressed into the ring-shapedframe101. Thecoupling member102 should be pressed into the ring-shapedframe104 until the everted end of thegraft vessel148 bears against the exterior surface of thetarget vessel wall150, creating a fluid tight seal at the anastomosis site. Alternatively, thecoupling member102, with the everted end of thegraft vessel148 attached, can be made to extend into theopening152 in thetarget vessel wall150 with thetarget vessel wall150 creating a radial compression around thegraft vessel148 and thecoupling member102. Thestapling mechanism119 can now be disengaged from the from the anchor member by turning thehandle126 of theouter tube125 with respect to the T-handle133 of thecraft insertion tool121 until the staple driver is withdrawn from theattachment legs105. Then theinner tube124 of the stapling device can be turned counterclockwise by turning the T-shapedhandle133 of thegraft insertion tool121 to disengage thegripping fingers144 of thestaple retainer123 from theattachment legs105 of theanchor member101. A complete end-to-side anastomosis, as shown in FIG. 5C, is left at the anastomosis site.
• It should be noted that the order of the steps of the[0109]anastomosis procedure127 could be altered. For instance, the opening could be first punched in the target vessel with an aortic punch or similar instrument, and then the anchor member of the staple could be attached. In this instance, the graft vessel could be attached to the anchor member either before or after the anchor member is attached to the target vessel. Other variations in the order of the steps are also possible.
• FIG. 7A shows a perspective drawing of a second embodiment of the[0110]graft insertion tool122 for use in performing the second anastomosis on a graft vessel, one end of which has already been anastomosed, or for other situations when both ends of the graft vessel are not available, such as when making the distal anastomosis on an internal mammary artery bypass graft. This embodiment of thegraft insertion tool122 is made with a two-part, hingedholder154 for the coupling member of the anastomosis staple device so that theholder154 can be removed from around thegraft vessel148 after both ends of the graft have been anastomosed. Theholder154 is attached to the distal end of atubular member155 which is attached on its proximal end to ahandle grip156. Ashaft157 is slidably received within thetubular member156. The distal end of theshaft157 is attached to aU-shaped yoke158 which is configured to grip aflange159 or a pair of lugs on the proximal end of theanchor member101. Thehandle grip156 has acoacting trigger member160 which is attached to the proximal end of theshaft157 through aslot161 in the side of thetubular member155. Theholder154 is spring biased toward theopen position154′. The force of the spring action helps theholder154 to grip thecoupling member102 so that it does not slip off of theholder154 prematurely. A distal end view of theholder154 is shown in FIG. 7B, with theholder154 shown in both the closed position and the open position (phantom lines154′).
• To prepare the[0111]graft vessel148 for the anastomosis, thecoupling member102 is first placed onto theholder154 and the end of thegraft vessel148 to be anastomosed is passed through thelumen162 of theholder154 and thecoupling member102 from the proximal to the distal end. The end of thegraft vessel148 is then everted back over thecoupling member102, as shown in FIG. 7C. The external surface features116 on thecoupling member102 will hold the everted vessel in place on the coupling member. In FIG. 7C, theanchor member101 of the anastomosisstaple device100 has been fastened to thetarget vessel150, as described above in relation to FIGS.5A-5E, and thestapling mechanism119 has been removed by turning thehandle126 of thestapling mechanism119 counterclockwise relative to thehandle126 on thevessel punch mechanism120 until the anchor member111 is released. Thegraft insertion tool122 with theprepared graft vessel148 is now positioned at the anastomosis site and theU-shaped yoke158 is used to grip theanchor member101, retained by theflange159 on its proximal end. With thegraft vessel148 and thecoupling member102 aligned with theanchor member101 as shown, thehandle grip156 and thetrigger160 are squeezed together to press thecoupling member102 into theanchor member101 until the everted end of thegraft vessel148 is pressed against the outer surface of thetarget vessel150 creating a leak-proof anastomosis. Theholder154 is then retracted from thecoupling member102 by moving thetrigger160 away from thehandle grip154. The hingedholder154 opens when it is withdrawn from thecoupling member102, releasing thegraft vessel148 from thelumen162 of theholder154. TheU-shaped yoke158 can now be slid sideways off of the anchor member and the anastomosis is complete.
• A one-piece version of the anastomosis staple device of the present invention along with a specially adapted staple applying tool will now be described in detail. In the one-piece embodiments which follow, a tubular member, analogous to the coupling member of the previously described embodiment, is permanently attached to a circular staple member, which is analogous to the[0112]anchor member101 of the previously described embodiment.
• FIG. 9 shows a perspective view of a first embodiment of the one-piece anastomosis[0113]staple device163 of the present invention. This same embodiment is shown in cross section in FIGS. 11 and 13. Theanastomosis staple163 has atubular body member164 which has aninner lumen165 sized to accommodate the exterior diameter of thegraft vessel148. Means for attaching thegraft vessel148 are provided at the distal end of thetubular body member164 or on the outside of thetubular member164. In the preferred embodiment, the means for attaching thegraft vessel148 to theanastomosis staple163 is a tubulardistal extension166 of the tubular body over which thegraft vessel148 is everted. Thetubular extension166 may include aflange167 to secure the attachment of the evertedgraft vessel148 to thetubular extension166. Thisflange167 may also engage the inner surface of thetarget vessel150 to help retain thegraft148 in place.
• The anastomosis[0114]staple device163 has a multiplicity ofstaple legs168 extending from thetubular body member164 proximal to the tubulardistal extension166. Optionally, thetubular body member164 may extend proximally169 from thestaple legs168 as shown, or the tubular body member can be truncated at or near the level of the staple legs to decrease the overall profile of the staple. The optionalproximal extension169 of thetubular body member164 may include lugs ortabs170 or a flange or other features that can be used for gripping the staple163 by a staple applying tool.
• The[0115]anastomosis staple163 typically has five to twelvestaple legs168 for attaching to thetarget vessel wall150. The presently preferred embodiment of thestaple163 has sixstaple legs168 as illustrated in FIG. 9. Thestaple legs168 are distributed circumferentially around the exterior of thetubular body member164. Thestaple legs168 can be formed integrally with thetubular body member164, or they can be manufactured separately and attached to thetubular body member164. Optionally, the exterior of thetubular body member164 may include acircumferential ledge171 to which thestaple legs168 are attached. In the pre-actuated position, thelegs168 angle proximally from where they attach to thetubular body member164 so that the sharpenedtips172 of the staple legs are proximal to the point of attachment with the body. Thestaple legs168 have afirst segment173 which extends approximately straight from the tubular body member; then there is atransitional segment174 and acurved end segment175. Thecurved end segment175 of each staple leg has a sharpenedtip172 for easily piercing the wall of thetarget vessel150. The curve of theend segment175 is a circular arc whose center of rotation coincides approximately with the point ofattachment176 between the staple leg and the tubular body member. The point ofattachment176 serves as a pivot point for thestaple leg168 when it is actuated, so that theend segment175 of thestaple legs168 describes an arc-shaped path through the tissue of the target vessel wall that follows the curvature of the arc-shapedend segment175.
• The[0116]transition segment174 of thestaple legs168 can take on one of several forms depending on the effect desired in the actuated staple. If thetransition segment174 is largely a right-angle bend, so that only theend segment175 penetrates the tissue, then thestaple legs168 will cause very little radial compression of the targetvessel wall tissue150 as thestaple163 is actuated. If, on the other hand, thetransition segment174 has a curve of smaller radius than that of thecurved end segment175, the tissue will be compressed and pulled toward thetubular body member164 as thetransition segment174 enters and travels through thetarget vessel wall150, as illustrated in FIG. 10. The degree of radial tissue compression can be regulated to the appropriate amount by proper design of the curve in thetransition segment174 of thestaple legs168. In addition, the shape of thefirst segment173 may help to define the surface shape of thetarget vessel150 after thestaple163 is applied. It may be desirable to keep it as flat as possible, or it may be desirable to “tent up” the target vessel somewhat in the area of the anastomosis. Optionally the first segment may be given greater effect on the target vessel surface shape by extending thefirst segment173 beyond the transition point with thesecond segment174, as shown in FIG. 11. The straight extension177 of thefirst segment173 beyond the attachment point of thetransition curve174 will tend to flatten out the tissue of thetarget vessel wall150 at the anastomosis site so that undue deformation of the vessel wall does not compromise the integrity of the anastomosis.
• FIG. 12 shows another means for accomplishing the tissue compression performed by the[0117]transition segment174 of thestaple lees168 in the embodiment of FIGS. 9 and 10. In this embodiment, thetransition segment174 of thestaple legs168 is essentially a right angle bend with very little radiusing, so thestaple legs168 cause very little tissue compression as they pierce thetarget vessel wall150 and travel through the tissue. However, before thestaple legs168 have reached the end of their travel, thefirst segment173 comes into contact with acircumferential ledge178 that extends outward from thetubular body member164 just below theattachment point176 of thestaple legs168. When thestaple legs168 contact theledge178, thefirst segments173 of the legs bend where they contact the outer edge of theledge178. This moves the center of rotation outward and shortens the radius of rotation of thecurved end segment175 so that the staple legs will pull the tissue of thetarget vessel wall150 toward thetubular body member164, compressing the tissue.
• The[0118]staple legs168 are preferably dimensioned so that the staple leas travel all the way through thetarget vessel wall150 when the staple is actuated. In the embodiment of FIG. 10, after actuation, theends172 of thestaple legs168 rest just distal to theflange167 on thedistal end166 of thetubular body member164. In the embodiment of FIG. 12, thestaple legs168 are configured to pierce the wall of thegraft vessel148 just proximal to theflange167 on thedistal end166 of thetubular body member164, adding to the security of the attachment. In both embodiments theflange167 supports the tissue of thetarget vessel wall150 as theends172 of thestaple legs168 emerge, helping to insure that thestaple legs168 will pierce cleanly through thetarget vessel wall150 without separating the lamina, which could lead to dissection. In both cases, thestaple legs168 are configured so that thecurved end segments175 of thestaple legs168 are driven all the way through thetarget vessel wall150 before there is significant compression of the tissues. Thetubular body member164 isolates the cut edge at theopening152 in thetarget vessel wall150 from the blood flow path so that blood pressure will not cause delamination of thetarget vessel wall150. Thestaple legs168, thetubular body member164 and theflange167 form a closed loop, similar to a sutured attachment. These factors also help to minimize the danger of dissection of thetarget vessel wall150.
• FIG. 13 shows one preferred embodiment of the one-[0119]piece anastomosis staple163 mounted on the distal end of a specially adaptedstaple applying tool179. Thestaple applying tool179 has anouter tube180 and aninner tube181 slidably received within theouter tube180. Theinner tube181 has aninner lumen182 of sufficient diameter to accommodate the outer diameter of thegraft vessel148 that will be used for the anastomosis. Thestaple applying tool179 has amain body183 which is shaped in the form of a pistol grip. The proximal end of theinner tube181 is anchored with respect to themain body183 by aflange184 or other attachment on the proximal end. Theouter tube180 is slidable with respect to theinner tube181 by actuating thelever185 of thestaple applying tool179 which engages a pair ofpins186 attached to the exterior of the outer tube. Pulling thelever185 advances theouter tube180 distally over the inner tube181. Areturn spring187 attached to thelever185 returns thelever185 and theouter tube180 to their unactuated positions.
• A close-up view of the[0120]anastomosis staple163 and the distal end of thestaple applying tool178 is shown in FIG. 14. Theanastomosis staple163 in this embodiment has atubular body164 which is permanently attached to a plurality of circumferentially distributedattachment leas168. Thetubular body164 has a distaltubular extension166 with aflange167 for eversion and attachment of thegraft vessel148. There is also a proximaltubular extension169 which has a pair oftabs170 for grasping the staple with astaple retainer188 on the distal end of theinner tube181 of thestaple applying tool179. An end view of thetabs170 is shown in FIG. 15A. Thestaple retainer188 at the distal end of theinner tube181 shown in detail in FIG. 15B, has a pair oflongitudinal slots189 corresponding to the twotabs170 of the anastomosis staple. Connected to thelongitudinal slots189 is acircumferential groove190 within theinner tube188. Thestaple163 is attached to thestaple retainer188 by aligning thetabs170 with thelongitudinal slots189 and sliding the tabs into theslots189. When thetabs170 reach the bottom of thelongitudinal slots189, thestaple163 is rotated with respect to theinner tube181 so that thetabs170 enter thecircumferential groove190. Aridge191 on the distal side of thegroove190 holds thetabs170 withingroove190 to retain the staple163 on the end of theinner tube181.
• It should be noted that a number of methods of attaching the[0121]tubular member164 to thestapling mechanism179 are possible besides the bayonet attachment illustrated. The end of thestapling mechanism179 may be configured to grasp thetubular member164 on the inner diameter or the outer diameter distal to the point ofattachment176 of thestaple legs168, allowing the proximaltubular extension169 of theanastomosis staple163 to be eliminated. This modification would allow a lower profile anastomosis attachment to be created.
• To prepare the[0122]graft vessel148 for anastomosis, ananastomosis staple163 is attached to the distal end of thestaple applying tool179 as just described, then, using a suture or an elongated grasping tool, thegraft vessel148 is drawn into theinner lumen182 of the tool until theend192 of thegraft vessel148 to be anastomosed extends a short distance from the distal end of the tool. At this point, theend192 of thegraft vessel148 to be anastomosed is everted over the distaltubular extension166 and theflange167 as shown in FIG. 14. A suture can be tied around theeverted end192 of thegraft vessel148 proximal to theflange167 to retain thegraft vessel148 on thestaple163, if desired.
• Thus prepared, the[0123]staple163 is advanced toward anopening152 that has been previously made in thetarget vessel wall150 with an aortic punch or other appropriate tool. Preferably, theopening152 is made with a diameter approximately equal to the outer diameter of the distaltubular extension166 of the staple163 just proximal to theflange167. Theflange167 with theeverted end192 of thegraft vessel148 is passed through theopening152 in thetarget vessel150, as shown in FIG. 10. Thetarget vessel wall150 may need to be stretched slightly to allow theflange167 to pass through theopening152. The elastic recovery of thetarget vessel wall150 creates a compressive force where thetarget vessel wall150 surrounds the distaltubular extension166 with theeverted end192 of thegraft vessel148 which contributes to the fluid-tight seal of the anastomosis.
• Once the[0124]flange167 has been passed through theopening152 in the wall of thetarget vessel150, theanastomosis staple163 is pulled back slightly so that theflange167, covered by the evertedgraft vessel wall192, is against the inner surface of thetarget vessel wall150. Then, thestaple167 is actuated by pulling on thelever185, which moves theouter tube180 distally until thestaple driver193 at the distal end of theouter tube180 bears on theattachment legs168. As thestaple driver193 advances, theattachment legs168 bend at thefulcrum176 where they attach to thetubular member164. The arc-shapedthird segments175 of theattachment legs168 penetrate and traverse the wall of thetarget vessel150. Once thethird segments175 of theattachment legs168 have traversed the wall, thestaple163 begins to compress the tissue of thetarget vessel wall150 radially against the distaltubular extension166 of theanastomosis staple163 by any of the mechanisms previously discussed. After theattachment legs168 of theanastomosis staple163 have been fully actuated, thelever185 is released and thestaple applying tool179 is rotated to disengage thestaple retainer188 from thetabs170 on the proximaltubular extension169 of thestaple163. Thestaple applying tool179 is withdrawn and the anastomosis is complete.
• FIG. 16 shows another potential configuration for the[0125]staple legs194 of the one-piece anastomosis staple195. In this embodiment, thestaple legs194 have a compound curved transition segment197 which provides two different axes of rotation for thestaple legs194 as they are actuated. Thestaple legs194 attach to the proximal end of thetubular body member198. Afirst segment199 of thestaple leg194 extends approximately radially from the point ofattachment206. There is aU-shaped bend200 at the end of thefirst segment199 that connects it to asecond segment201 which lies roughly parallel to thefirst segment199. Athird segment202 attaches thesecond segment201 to the fourth, and most distal,segment203 of the staple leg. Thefourth segment203 has an arc-shaped curve whose center of rotation is approximately at the center of theU-shaped curve200 between the first199 and second201 segments. Thedistal tip204 of thefourth segment203 is sharpened so that it easily penetrates thetarget vessel wall150.
• In the operation of this embodiment of the anastomosis staple, the[0126]staple legs194 are initially in the position shown bysolid lines194 in FIG. 16. In this position thestaple legs194 are held well above theflange205 on the distal end of the tubular body member, making it easier to insert theflange205, with the evertedgraft vessel192 attached, into the opening in thetarget vessel150 and to seat theflange205 against the inner surface of thetarget vessel150. When the staple driver is advanced, thestaple legs194 initially rotate aboutattachment point206 between the first segment and the tubular body member. After thestaple leg194 has rotated approximately 90 degrees, to the position shown byphantom lines194′, thefirst segment199 comes into contact with the exterior of thetubular body member198 and it stops rotating. Advancing the staple driver further causes the second201, third202 and fourth203 segments of thestaple leg194 to rotate around theU-shaped curve200 connecting the first199 and second201 segments. TheU-shaped curve200 opens up to about90 degrees as the curvedfourth segment203 of thestaple leg194″ penetrates thetarget vessel wall150, attaching thegraft vessel148 to thetarget vessel150 to complete the anastomosis.
• Another embodiment of the two-piece anastomosis staple is shown in FIGS.[0127]17A-17D. This embodiment differs somewhat in its construction from the embodiment of FIG. 1 although the operational principles are basically the same. Theanastomosis staple207 again includes ananchor member208 and acoupling member209 which interconnect. Theanchor member208 is made with a ring-shapedframe210 which is pierced by two parallel rows ofslots211,212. Themetal213 between theslots211,212 is deformed outward slightly to allow insertion ofwire attachment legs214. After theattachment legs214 are inserted, themetal213 is pressed inward to firmly attach thewire attachment legs214 to theframe210. Either before or after attachment to the ring-shapedframe210, thewire attachment legs214 can be formed with a desired curve, such as one of the curves described in FIGS.8A-8G. Thedistal tips215 of the wire attachment legs are sharpened so that they easily penetrate thetarget vessel wall150. The use of roundwire attachment legs214 with conically sharpenedpoints215, as opposed to theflat attachment legs105 with chisel-shapedpoints212 of FIG. 1, has shown some advantage in preliminary testing, in that theround wire legs214 cause less trauma to the tissue of thetarget vessel wall150 as they penetrate it. This may be due to the tendency of the conically sharpenedtips215 of theattachment legs214 to dilate the tissue as they pass through thetarget vessel wall150 more than to cut it. The tissue of thetarget vessel wall150 is thus left more intact and may be less prone to dissections or other structural failure.
• A plurality of retaining[0128]clips216 are integrally formed on the proximal edge of the ring-shapedframe210. The retaining clips216 perform the function of coupling the anchor member to the coupling member, similar to the interior surface features117 of theanchor member101 of FIG. 1. Thecoupling member209, shown in FIG. 17B, has atubular body217 with a plurality of graft holding points218 extending from its distal edge. If desired, the graft holding points218 could be relocated, replaced with other gripping features, or eliminated entirely to avoid piercing thegraft vessel148 at the point of eversion. The graft holding points218 perform one of the functions of the exterior surface features116 of thecoupling device102 shown in FIG. 1 in that they attach thegraft vessel148 to thecoupling member209.
• This embodiment of the two-[0129]piece anastomosis staple207 can be applied with a slightly modified version of theanastomosis stapling tool118 of FIGS. 2, 6 and7, following the sequence of steps of FIGS.5A-5G. Theinner tube124 of thestapling mechanism119 grasps theanchor member208 by either the ring-shapedframe210 or the first segment of the attachment legs with the L-shaped legs of the staple retainer. After asmall incision151 has been made in thetarget vessel wall150 at the desired anastomosis site, thestapling mechanism119, with thevessel punch mechanism120 inserted into theinner lumen128, is positioned at the anastomosis site. Theanvil136 of thevessel punch120 is inserted through theincision151 and drawn back slightly to support thetarget vessel wall150 so that thewire attachment legs214 can be driven into thewall150. Thewire attachment legs214 are then deformed by thestapling mechanism119 to attach theanchor member208 to thetarget vessel wall150. Thevessel punch120 is then actuated to form ahole152 through thetarget vessel wall150 centered within the ring-shapedframe210, as described in relation to FIG. 5D. Theanchor member208 is now attached to thetarget vessel wall150 with the ring shaped frame centered around the opening in thevessel wall152, as shown in FIG. 17B. In this illustrative embodiment, thewire attachment legs214 are configured so as to only partially penetrate thetarget vessel wall150 so that they are embedded within thetarget vessel wall150 in their final, deployed configuration. This variation of the method may be preferred for attachment to some types of body tissues as thetarget vessel150. Thewire attachment legs214 may also be pierced through the entiretarget vessel wall150 before they are deformed so that they reside against the interior of thetarget vessel wall150, as shown in FIG. 5C.
• Once the[0130]anchor member208 is attached to thetarget vessel150, thevessel punch mechanism120 is withdrawn and thegraft insertion tool121 with thegraft vessel192 everted over the distal end of thecoupling member209 is inserted into theinner lumen128 of thestapling mechanism119. Thegraft insertion tool121 is used to press thecoupling member209 into the ring-shapedframe210 of theanchor member208 until theeverted end192 of thegraft vessel148 is firmly sealed against the outer surface of thetarget vessel wall150 and the retainingclips216 have seated over the proximal end of thecoupling member209. Thecoupling member209 is held in the ring-shapedframe210 by the retaining clips216. The graft holding points218 may be made so that they penetrate through thegraft vessel wall192 and into thetarget vessel wall150, as shown in FIG. 17C, to increase the security of the anastomosis attachment. It should be noted that other sequences of operations are also possible for this embodiment, such as punching the opening in the target vessel wall prior to attachment of the anchor member.
• Another embodiment of the two-piece anastomosis[0131]staple device219 is shown in FIGS.18A-18F. This embodiment of the device lends itself to different manufacturing methods than the previously described embodiments. Theanchor member220 shown in perspective in FIG. 15A can be formed from a single piece of sheet metal by a combination to punching and drawing steps. Theanchor member220 has aplate221 which is curved to fit the contours of the exterior surface of thetarget vessel wall150, as seen in the end view FIG. 18B. For performing an aortic anastomosis, the radius of curvature of theplate221 would typically be between 10 and 20 mm in an adult human. Theplate221 would be approximately 10 to 20 mm in width and 10 to 25 mm in length. Theplate221 is punched so as to formintegral attachment legs222. This illustrative embodiment is shown with four integrally formedattachment legs222, as best seen in top view FIG. 18C. A tubularproximal extension223 is formed on thecurved plate221 by drawing thesheet metal plate221 to form acylindrical extension223, then piercing or drilling it to open the proximal end of the cylinder. A final forming or stamping operation forms aradiused flange224 at the proximal end of thetubular extension223 that serves as a strain relief to prevent sharp bends or kinking of thegraft vessel148 close to the anastomosis site.
• This embodiment of the anchor member can be attached to the target vessel wall by a sequence of operations similar to that described in relation to FIGS.[0132]5A-5G. Alternatively, the sequence of operations can be re-ordered so that the target vessel is punched before placement of the anchor member similar to that described for the one-piece embodiment of FIG. 9. Thus, either of theanastomosis stapling mechanisms118,179 previously described could easily be adapted to hold theanchor member208 of FIG. 18 and to drive theattachment legs222 into thetarget vessel wall150.
• The[0133]coupling member225 in this embodiment is atoroidal ring225 made of a resilient biocompatible material such as plastic, rubber or a springy metal having an outside diameter slightly smaller than the inside diameter of thecylindrical extension223. Thecoupling member225 is shown in FIG. 18D. Thegraft vessel148 is prepared for anastomosis by passing the end of the vessel through the central opening of thetoroidal ring225 and everting it back192 over the ring, as shown in the FIG. 18E. Thering225, with thegraft vessel192 everted over it, is then collapsed or folded enough so that it can be inserted into the proximaltubular extension223 of theanchor member220. Once through thecylindrical extension223, thetoroidal ring225 recoils to its expanded size, sealing thegraft vessel wall192 against the wall of thetarget vessel150 and preventing the end of thegraft vessel192 from pulling out of thetubular extension223. Alternatively, a cylindrical ring-shaped coupling member with locking features, similar to those shown in FIGS. 1 and 17B, can be used in conjunction with the anchor member of FIG. 18A.
• FIGS. 19A and 19B show an[0134]alternate construction226 of the two-piece anastomosis staple219 device of FIGS.18A-18E. In this variation of the device, theanchor member227 may be made from a flat piece of sheet metal that is punched to form aflange238 with acentral aperture228 and integrally formedattachment legs229. Theanchor member227 is attached to thetarget vessel150 with the central aperture aligned228 with apreformed hole152 in the wall of thetarget vessel150. Alternatively, theanchor member227 can be placed before thehole152 is punched. Theattachment legs229 are shaped with straight distal segments, as shown by thephantom lines231′, that penetrate thetarget vessel wall150 in a linear fashion. A stapling device with a staple deforming anvil is passed through thehole152 in thetarget vessel wall150 to deform theattachment legs229 so that they grip thetarget vessel wall150, as shown by thesolid lines231. Theattachment legs229 can be deformed one at a time or some or all of theattachment legs229 can be deformed at once depending on the design of the stapling device. Alternatively, theattachment legs229 can be precurved and driven into thetarget vessel wall150 from the outside.
• The[0135]central aperture228 in theflange230 of theanchor member227 has attachment features that interlock with matching attachment features on a firsttubular coupling member232. As an illustration of one possible configuration, the first coupling member is shown with two pairs oftabs233,234 extending radially from the distal edge of the firsttubular coupling member232. One pair oftabs234 is slightly more distal than theother pair233. Thecentral aperture228 of theanchor member227 has a matching pair ofslots235 extending from theaperture228. Thefirst coupling member232 is joined to theanchor member227 by aligning the more distal pair oftabs234 with theslots235, pushing thetabs234 through theslots235, then turning thecoupling member232 until thetabs234 are locked onto the edges of theaperture228. The firsttubular coupling member232 may be made with integrally formed graft holding points236 which are cut and bent inward from the wall of the firsttubular coupling member232 to hold the everted graft in place. The graft may be everted over a secondtubular coupling member196, which is inserted into the firsttubular coupling member232 and is attachable to the first tubular coupling member at the proximal ends of the tubular coupling members, as shown in FIG. 19B.
• FIG. 20 shows a fourth[0136]alternate construction237 of the two-piece embodiment of the anastomosisstaple device100 of FIG. 1. Theanchor member238 of the anastomosisstaple device237 may be formed from a piece of sheet metal, similarly to the other alternate embodiments previously described. Theanchor member238 has adistal plate239 which may be flat or curved to match the exterior curvature of thetarget vessel150.Multiple attachment legs240 are cut from theplate material239, sharpened at theends241, and bent with afirst section242 that angles upwardly from theplate239 and asecond section243 that is angled downward to pierce the target artery wall, as shown inphantom lines243′ in FIG. 20. Preferably, thesecond section243 is curved with a radius of curvature approximately equal to the length of thefirst section242. A tubularproximal extension244 with a slight hourglass shape extends from thedistal plate239 of theanchor member238.
• The[0137]coupling member245 of the anastomosisstaple device237, shown in FIG. 20, is made in a tubular shape of a biocompatible resilient material such as plastic, rubber or a springy metal, such as a nickel-titanium alloy. Thetubular coupling member245 has a slight hourglass shape in axial cross section, matching the interior shape of the tubularproximal extension244 of theanchor member238. If desired, thetubular coupling member245 can be made with slightly thickened proximal246 and distal247 extremities which act as O-rings molded integrally with the wall of the tube. Thetubular coupling member245 can be made with a continuous tubular wall or with a longitudinal slot in the wall of the tube to increase the resiliency of the coupling member. Alternatively, thetubular coupling member245 can be made of a coiled spring with an hourglass shape in axial cross section.
• As with the previously described embodiments, the[0138]anchor member238 can be applied to the exterior of thetarget vessel150 either before or after anopening152 has been created with a vessel punch. To place theanchor member238, theplate239 of theanchor member238 is pressed against the exterior surface of thetarget vessel150 at the anastomosis site and theattachment legs240 are pressed to drive the sharpenedtips241 through thetarget vessel wall150. If anopening152 has not yet been made in thetarget vessel wall150, a vessel punch is inserted through thelumen244 of the proximaltubular extension244 to create anopening152 in thewall150 concentric with thetubular extension244.
• Meanwhile, the[0139]graft vessel148 is prepared by placing it through the lumen of the tubular coupling member and everting theend192 of thegraft vessel148 over the outside of thecoupling member245. To complete the anastomosis, thecoupling member245 with theend192 of thegraft vessel148 attached is collapsed or folded and inserted into the proximaltubular extension244 of theanchor member238. The resilience of thecoupling member245, combined with the matching hour-glass shapes of the two parts of the staple device, locks the parts together to form a leak-proof anastomosis.
• The[0140]coupling member245 can be dimensioned so that the distal end of thecoupling member245 extends through theopening152 in the target vessel wall and the evertededge192 of thegraft vessel148 seals within theopening152, as illustrated, or against the interior surface of thetarget vessel150 similarly to the one-piece embodiment of the anastomosis staple device illustrated in FIG. 9.
• Alternatively, the[0141]coupling member245 can be shaped so that it presses the evertededge192 of thegraft vessel148 against the exterior surface of thetarget vessel150 to create a leak-proof seal similar to the embodiment of FIG. 1.
• In a further aspect of the invention, an anastomosis fitting is provided for rapidly and reliably creating an end-to-side anastomosis between a graft vessel and a target vessel. A first representative embodiment of an[0142]anastomotic fitting250 according to this second aspect of the present invention is shown in FIGS.21A-21C. Theanastomotic fitting250 is made up of two coacting parts: a) a tubularinner sleeve251 which has aninternal lumen252 of sufficient size to accommodate the external diameter of thegraft vessel254 and aninner flange253 which is attached or formed at the distal end of thesleeve251 so as to be positioned within thelumen256 of thetarget vessel255, and b) anouter flange260 which has acentral orifice261 that is sized to fit over the exterior of theinner sleeve251 to be positioned against theexterior surface258 of thetarget vessel wall255. Theanastomotic fitting250 is thus held in place by compressing thetarget vessel wall255 between the inner253 and outer260 flanges. Anadjustable locking mechanism262 holds theouter flange260 on theinner sleeve251 at a selected position to create a tailored degree of tissue compression at the anastomotic site. The anastomosis fitting250 can be made of various biocompatible materials, such as stainless steel, titanium alloys, plastic, pyrolytic carbon, etc. Additionally, biocompatible coatings could be applied to the inner and/or outer surfaces of the fitting250 to increase its acceptance by the body tissues or to reduce thrombosis.
• The[0143]inner sleeve251 is a tubular member with aninternal lumen252 large enough to accommodate the external diameter of thegraft vessel254, either a natural graft vessel or an artificial graft vessel. Natural saphenous vein autografts typically have an internal diameter between 3 mm and 10 mm and an external diameter between 4 mm and 11 mm. Pedicled arterial grafts, such as the internal mammary artery or the gastroepiploic artery typically have an internal diameter between 2 mm and 7 mm and an external diameter between 3 mm and 8 mm, with thicker, more muscular walls. Artificial prosthetic graft vessels, made of materials such as Dacron or Goretex. typically have a diameter of 3 mm to 30 mm. The tubularinner sleeve251 should be made of a rigid biocompatible material, such as stainless steel, titanium alloys or a rigid biocompatible plastic. The wall thickness of the sleeve is preferably about 0.2 mm to 2.0 mm.
• The distal end of the inner sleeve is flared at an angle of approximately 45 to 75 degrees to form a conical[0144]inner flange253. Theinner flange253 has an outer diameter of approximately 1.3 to 2.5 times the inner diameter of theinner sleeve251. The use of a conical or roundedinner flange253 helps to improve the hemodynamic efficiency of the anastomosis connection by improving the orifice coefficient at the entrance to thegraft vessel254. It also assures that the finished anastomosis will not protrude into thelumen246 of thetarget vessel255 or upset the hemodynamic flow in that vessel. The exterior of the tubularinner sleeve251 has a series ofcircumferential ridges263 or threads which may be saw-tooth in shape.
• The[0145]outer flange260 as acentral orifice261 which is sized to fit over the exterior of the tubularinner sleeve251. Theouter flange260 has an outer diameter of approximately 1.3 to 3.0 times the inner diameter of theinner sleeve251. Aratchet mechanism264 within or adjacent to thecentral orifice261 of theouter flange260 engages thecircumferential ridges263 on the exterior of the tubularinner sleeve251. Theratchet264 can be strictly a one-way mechanism so that theouter flange260 can only move in the direction of theinner flange253 or a release mechanism can be incorporated so that theouter flange260 can be moved away from theinner flange253 in case of premature activation of theratchet mechanism264. Alternatively, theouter flange260 could be threaded to the exterior of the tubularinner sleeve251. Thedistal edge265 of theouter flange260 may incorporate a plurality of attachment spikes266 that engage and hold the wall of thetarget vessel255 and/or the evertedwall259 of thegraft vessel254 when theouter flange260 is applied. In the preferred embodiment which is intended for creating an anastomosis between a coronary arterv bypass graft and the ascending aorta, theouter flange260 has 4 to 12 spikes of 1 to3 mm length and 0.2 to 0.5 mm diameter. Variations of this configuration may be made where appropriate for different graft vessels and target vessels.
• The anastomosis is performed by passing the[0146]end259 of thegraft vessel254 through theinner lumen252 of the tubularinner sleeve252 until the end of the vessel extends a short distance from the distal end of the sleeve, as shown byphantom lines259 in FIG. 21A. Theend259 of thegraft vessel254 is then everted over the conicalinner flange253 of the fitting250 to form an atraumatic attachment, as shown in FIG. 23A. If desired, a loop of suture can be tied around theeverted end259 of thegraft vessel254 to hold it in place on theinner flange253 and/or the tubularinner sleeve251. The conicalinner flange253 and theeverted end259 of thegraft vessel254 are then passed through anopening267 that has previously been made in the wall of thetarget vessel255 with an instrument such as a vessel punch, as shown in FIG. 21B. The diameter of theopening267 in the target vessel wall is preferably about the same as the external diameter of the tubularinner sleeve251. Theopening267 may need to stretch slightly to allow the conicalinner flange253 to pass through. The elastic recovery of thetarget vessel wall255 around theopening267 helps to create an anastomotic seal by contracting around theinner sleeve251 and the evertedgraft vessel wall259. Theouter flange260 is then slid onto the proximal end of theinner sleeve251. If the anastomosis being performed is the first anastomosis of a free graft, such as a saphenous vein graft, with the other end of the graft unattached, then theouter flange260 can be slid over thegraft vessel254 from the free end. If the other end of thegraft vessel254 is not free. such as when performing a second anastomosis or a distal anastomosis on a pedicled graft like the IMA, then theouter flange260 should be back loaded onto thegraft vessel254 or preloaded onto the proximal end of theinner sleeve251 before theend259 of thegraft vessel254 is attached to theinner flange253 of the fitting250. Theouter flange260 is slid down theinner sleeve251 until it contacts theexterior wall258 of thetarget vessel255 and a desired degree of compression of thetarget vessel wall255 is applied between the inner253 and outer260 flanges. Theratchet mechanism264 of theouter flange260 locks theflange260 in place on the tubularinner sleeve251 to complete the anastomosis, as shown in FIG. 21C.
• FIGS.[0147]22A-22D show an anastomosis fitting268 which is a variation of the embodiment of FIGS.21A-21C. In this variant theinner flange269 has a flat annular configuration, rather than a conical shape as in the previously described embodiment. To insure that the completed anastomosis does not protrude into theblood flow lumen256 of thetarget vessel255, theouter flange270 of the fitting is concave on itsdistal surface271. Thecentral orifice272 of theouter flange270 tapers proximally to alocking ring273 within thecentral orifice272 that slips over and locks with acollar274 on the proximal end of the tubularinner sleeve275. As shown in FIG. 22C, when theouter flange270 is applied to theexterior surface258 of thetarget vessel255 and locked onto thecollar274 of the tubularinner sleeve275, theinner flange269 is drawn into the concaveouter flange270, so that the anastomosis is flush with or recessed into theinner wall257 of thetarget vessel255. This helps to assure a hemodynamically correct inflow at the entrance to thegraft vessel254. Two ormore collars274 may be provided on the tubularinner sleeve275 to allow adjustable compression by theanastomotic fitting268.
• FIGS.[0148]23A-23D show anothervariant276 of the embodiment of the anastomosis fitting of FIGS.21A-2lC and FIGS.22A-22D. In this variant the concaveouter flange277 has a simplecentral orifice278 without a locking ring. The locking mechanism is provided by multiple downwardly orientedtangs279 or tapered ridges, which have been formed in the10 sidewall of the tubularinner sleeve280 by cutting, punching or molding. Theouter flange277 is slid over the proximal end of theinner sleeve280 and over thetangs279, which engage the proximal end of theouter flange277 to lock theouter flange277 into place on theinner sleeve280, as illustrate in FIG. 23C. If desired, multiple parallel rows oftangs279 can be provided at different axial locations on theinner sleeve280 to accommodate different thicknesses of thetarget vessel wall255 and to provide a tailored degree of tissue compression at the anastomosis site. Optionally, the underside of theouter flange277 may have a plurality of attachment points which engage and hold thetarget vessel wall255 near theopening267 in it, adding security to the anastomosis attachment without piercing thetarget vessel wall255.
• FIGS.[0149]23A-23D also illustrate a variation of the method for applying the anastomosis fitting. In this embodiment, the method includes applying asuture281 to theeverted end259 of thegraft vessel254 to secure it to theinner flange282. As best seen in the top view FIG. 23D, theeverted end259 of thegraft vessel254 has been secured to theinner flange282 of the fitting by making a running stitch around the end of the graft vessel with asuture281 on the back of theinner flange282 and tying it to create a purse string that holds theend259 of thegraft vessel254 in place.
• A second representative embodiment of an[0150]anastomotic fitting283 employing inner284 and outer285 flanges has an expandinginner flange284 which facilitates the atraumatic attachment of thegraft vessel254 to the fitting283 and makes it easier to pass theinner flange284 and theeverted graft vessel259 through theopening267 in thetarget vessel wall255. Two variations of such an expanding inner flange are shown in FIGS.24A-24D and FIGS.25A-25H. Thegraft vessel254 is passed through aninternal lumen287 of aninner sleeve286 which has the expandableinner flange284 attached at its distal end. Theend259 of thegraft vessel254 is everted over the unexpandedinner flange284′. Theinner flange284′ and theeverted end259 of thegraft vessel254 are passed through theopening267 in thetarget vessel wall255. Once theinner flange284′ of the fitting283 is in thelumen256 of thetarget vessel255, it is expanded to adiameter284 which is significantly larger than theopening267 in thetarget vessel wall255. Then anouter flange285 is applied and locked into a selected position on theinner sleeve286 as described above to complete the anastomosis.
• In the first variant of the expanding[0151]inner flange284, shown in FIGS.24A-24D, theflange284 and a portion of theinner sleeve286 are slotted to createmultiple fingers288 which are initially collapsed inward toward the center of theinner sleeve286. The ends of the fingers form sector-shapedsections289 of theflange284, as seen in the distal end view of FIG. 24D. When theflange284 is collapsed inward284′, as in FIG. 24C, thesectors289 fit together to form asmaller diameter flange284′ with apassage287′ through the center large enough for acollapsed graft vessel254 to fit through. A tubular former290 is slidably received within the slottedinner sleeve286 and has an axial lumen291 large enough to receive thegraft vessel254. The tubular former290 initially resides in a proximal position, as shown in FIG. 24A. The tubular former290 has aridge292 at its proximal end that positions the tubular former290 in the correct location with respect to theinner sleeve286 when the tubular former290 is in its distal, deployed position. Anouter flange285, with a concavedistal surface293 may be permanently attached to theinner sleeve286 proximal to the expandinginner flange284. Alternatively, theouter flange285 can be provided as a separate component which is attached to the inner sleeve2S6 after thegraft vessel254 has been attached or at the end of the anastomosis procedure.
• In operation, the[0152]graft vessel254 is inserted through the axial lumen291 of the tubular former290 and through theinternal lumen287 of the slottedinner sleeve286 and through thecentral opening287′ between thecollapsed sectors289′ of theinner flange284′. Theend259 of thegraft vessel254 is everted over thecollapsed sectors289′ of theflange284′. Thecollapsed flange282′ and theeverted end259 of thegraft vessel254 are inserted through theopening267 in thetarget vessel255. Then, the tubular former290 is slid distally within the slottedinner sleeve286. The tubular former290 forces thefingers288 outward, expanding theflange284 within thetarget vessel255. If theouter flange285 is already attached to theinner sleeve286 at this point, thedistal surface283 of theouter flange285 is pressed against theexterior surface258 of thetarget vessel255 as the expandableinner flange284 is being deployed to complete the anastomosis. If, on the other hand, theouter flange285 has been supplied as a separate component, theouter flange285 is slipped over the proximal end of theinner sleeve286 after the expandableinner flange284 has been deployed and a desired degree of tissue compression is applied between the inner284 and outer285 flanges of the fitting283 to complete the anastomosis, as shown in FIG. 24B.
• A second variant of the[0153]anastomotic fitting294 with an expandinginner flange298 is shown in FIGS.25A-25H. The inner sleeve295 of the fitting294 is slotted along its entire length to formmultiple fingers296 that are oriented essentially longitudinally to the inner sleeve295. Acollar297 on the proximal end of the slotted inner sleeve295 joins themultiple fingers296 together in a tubular configuration. A concaveouter flange299 is captured on the slotted inner sleeve295 by theproximal collar297. As seen in the end view in FIG. 25E, the inside diameter of thecollar297 hasnotches301 which are extensions of theslots300 between thefingers296 of the inner sleeve295. Each of thefingers296 has abend302 in it to predispose it to bend outward at the middle when contracted longitudinally. A tubular formingtool303 for expanding theinner flange298 is slidably received within the slotted inner sleeve295. The distal end of the tubular formingtool303 is crenellated with multipleradially extending tabs304. The multiple radially extendingtabs304, as seen in the end view in FIG. 25F, are configured to fit through thenotches301 in thecollar297 and into theslots301 of the inner sleeve. The tubular formingtool303 is inserted into the slotted inner sleeve295 by aligning theradially extending tabs304 with thenotches301 in thecollar297 and sliding it distally along theslots300 until thetabs304 pass the distal ends305 of thefingers296. Then, the tubular formingtool303 is rotated slightly so that theradially extending tabs304 engage the distal ends305 of thefingers296 of the slotted inner sleeve295, as shown in FIG. 25A.
• The anastomosis is performed by passing the[0154]graft vessel254 through the internal lumen of the formingtool303 within the slotted inner sleeve295 and everting it259 over the distal ends305 of thefingers296. A loop ofsuture306 can be used to hold the evertedvessel259 in place. Thefingers296 of the fitting294 and theeverted end259 of thegraft vessel254 are inserted through anopening267 in thetarget vessel wall255. When the tubular formingtool303 is slid proximally with respect to the slotted inner sleeve295, theradially extending tabs304 of the tubular formingtool303 bear against the distal ends305 of thefingers296 compressing them longitudinally. Thefingers296 bow outward, folding at thebend302 to expand and create aninner flange298 which engages theinner surface257 of thetarget vessel wall255. The tubular formingtool303 is pulled further proximally until the newly formed inner flange is drawn into the concaveouter flange299, compressing thetarget vessel wall255 and recessing theinner flange298 and the anastomotic connection into thetarget vessel wall255, as shown in FIG. 25D. The tubular formingtool303 can now be removed by rotating it with respect to the slotted inner sleeve295 so that the tabs align with theslots300 and withdrawing it from the fitting294. The mass of foreign material that is left as an implant at the anastomotic site is thus reduced.
• Alternatively, the inner sleeves[0155]295 and the tubular formingtool303 can be formed integrally or welded together as one piece, in which case both the inner sleeve295 and the tubular formingtool303 would remain in the finished anastomosis. As a further alternative, the tubular formingtool303 could be made to break away from the inner sleeve295 when a certain force is applied.
• In a further aspect of the invention, the anastomotic fitting has a single-piece construction with an inner sleeve that is integrally attached to a fixed inner flange and to a deformable outer flange. Three variants of the anastomotic fitting with a deformable outer flange and their forming tools are shown in FIGS.[0156]26A-261,27A-27D and28A-281.
• The first variant of the[0157]anastomotic fitting306 with a deformable outer flange is shown in FIGS.26A-26I. Theanastomotic fitting306 has a tubularmain body307 having aninternal lumen303 sized to accommodate the external diameter of thegraft vessel254. A fixedinner flange309 is attached to the distal end of thetubular body307. On the proximal end of thetubular body307 are a plurality of hingedly attachedouter flange segments310. In this illustrative embodiment, there are foursuch flange segments310 which are enlarged at their outer edges to form sector-shapedsegments310 of theouter flange311. Thehinge portion312 of eachflange segment310 is a deformable strip ofmetal312 connecting theflange segment310 to the maintubular body307. Preferably, thetubular body307, theinner flange309 and theflange segments310 of theouter flange311, including thedeformable hinge portion312, are integrally formed of a single piece of biocompatible metal, such as stainless steel, a titanium alloy or a cobalt alloy (e.g. Carpenter MP35).
• The distal end of a[0158]device313 for applying the anastomosis fitting is shown in FIG. 26B. The device has an inner tubular member known as theanvil314 and an outer tubular member called thedriver315. The distal end of theanvil314 has agripper316 for holding onto theanastomosis fitting306. Thegripper316 in the preferred embodiment has a bayonet-type fitting with four L-shapedgripping fingers317 which hold the fitting306 by hooking onto each of theflange segments310 at thedeformable hinge portion312. The driver slides315 telescopically over the outside of theanvil314 and has anannular driving surface318 on its distal end configured to engage the outer ends of eachflange segment310. Theanvil314 and thedriver315 can be made in a long version, approximately 15 to 30 cm in length, for performing port-access CABG surgery or a short version, approximately 10 to 20 cm in length, for performing standard open-chest CABG surgery.
• The fitting[0159]306 is prepared for performing the anastomosis by attaching the fitting306 to thegripper316 on the distal end of theanvil314. Then, thegraft vessel254 is passed through theinner lumen319 of theanvil314 until theend259 to be anastomosed extends a short distance from the distal end of the fitting306. The end of thegraft vessel259 is everted over theinner flange309 of the fitting to form an atraumatic attachment between the two. If the anastomosis being performed is part of a port-access CABG surgery procedure, the fitting on the end of the application tool is inserted into the patient's chest through an access port made through one of the intercostal spaces. Theinner flange309 and theeverted end259 of thegraft vessel254 are inserted through anopening267 that has been made in the wall of thetarget vessel255. The fitting306 is pulled back slightly so that theinner flange309 is flush against theinterior surface257 of the target vessel. Then, thedriver315 is pushed distally with respect to theanvil314 until the drivingsurface318 deforms theouter flange segments310 against theexterior surface258 of thetarget vessel wall255 and the desired degree of compression of thevessel wall255 is obtained. Theanvil314 is rotated slightly to release thegripper316 from theflange segments310 of the fitting306 and theapplication device313 is withdrawn from the patient's body.
• The second variant of the[0160]anastomotic fitting320 with a deformableouter flange321 is shown in FIGS.27A-27D. This variant is largely the same as the first variant just described in connection with FIGS.26A-26I with the exception of theinner flange322 construction. In this embodiment, theinner flange322 is slightly conical in order to provide a more hemodynamically efficient inlet to thegraft vessel254 at the anastomosis. In addition, a plurality of attachment spikes323 preferably 6 to 8 spikes, have been provided along the periphery of theinner flange322. In a preferred configuration, theanastomotic fitting320 is fully deployed, thespikes323 penetrate through the evertedwall259 of thegraft vessel254 and into the wall of thetarget vessel255 to create a more secure attachment for the anastomosis. When theouter flange segments324 are deformed against theexterior surface258 of thetarget vessel255 and compress thevessel wall255 such that they engage thespikes323 on theinner flange322 for a very secure attachment.
• The third variant of the[0161]anastomotic fitting325 with a deformableouter flange326 is shown in FIGS.28A-281. Theanastomotic fitting325 has a tubularmain body327 with aninternal lumen328 sized to accommodate the external diameter of thegraft vessel254. The walls of thetubular body327 have a pair of L-shapedslots329 that are open at the top of thetubular body327 to form a bayonet fitting. Aninner flange330, which may be slightly conical in shape, is attached to the distal end of thetubular body327. Attached to the proximal end of thetubular body327 is a deformableouter flange326, comprising a multiplicity of axially-orientedbars331 separated by axial slots,332 The axially-orientedbars331 are attached at their distal ends to the tubularmain body327, and are joined at their proximal ends by aring333 forming the proximal end of the fitting325 Thebars331 are bent outwardly near theircenters334 so that thebars331 preferentially bend outwardly when compressed. Thetubular body327, theinner flange330 and the deformableouter flange326 are preferably machined of a single piece of biocompatible metal, such as stainless steel, a titanium alloy or a cobalt alloy. The geometry of this device could also be configured so that thebars331 of theouter flange326 start off almost straight, and are deformed further to reach their final geometry.
• A[0162]device335 or applying the anastomotic fitting is shown in FIG. 28D-F. Thedevice335 has an innertubular member336 which has a pair of radially extendingtabs337 on its distal end that interlock within the L-shapedslots329 in thetubular body327 of the fitting325. An outertubular member338, thepusher338, slides telescopically over the outside of the innertubular member336 and has anannular driving surface339 on its distal end. This anastomosisfitting application device335 can be made in a long version for port-access CABG surgery or a short version for standard open-chest CABG surgery.
• The fitting[0163]325 is prepared for performing the anastomosis by attaching theanastomotic fitting325 to the innertubular member336. Then, thegraft vessel154 is passed through theinner lumen340 of the innertubular member336 until theend159 to be anastomosed extends a short distance from the distal end of the fitting325. Theend159 of thegraft vessel154 is everted over theinner flange330 of the fitting325 to form an atraumatic attachment, as shown in FIG. 28D. If the anastomosis being performed is part of a port-access CABG surgery procedure, the fitting325 on the end of theapplication tool335 is inserted into the patient's chest through an access port made through one of the intercostal spaces. Theinner flange330 and theeverted end159 of thegraft vessel154 are inserted through anopening267 that has been made in the wall of thetarget vessel225, as shown in FIG. 28E. The fitting325 is pulled back slightly so that theinner flange330 is flush against theinterior surface257 of thetarget vessel255. Then, thepusher338 is moved distally with respect to the innertubular member336 until the drivingsurface339 contacts the proximal surface of the deformableouter flange326. Thepusher338 deforms theouter flange326 by compressing thebars331, which bend outwardly and fold into a flattened configuration, as shown in FIG. 28F, to form a radially spokedouter flange326′. Thepusher338 further deforms thebars331 to press theouter flange326′ against theexterior surface258 of thetarget vessel wall255 and obtain the desired degree of compression between the inner330 and outer326′ flanges. The innertubular member336 is removed by rotating it with respect to the fitting325 and withdrawing the tabs from the L-shapedslots329.
• A further embodiment of an anastomosis fitting[0164]340 according to the invention is illustrated in FIG. 29A-C. The anastomosis fitting of FIG. 29A-C may be particularly advantageous with older patients, diabetic patients and other patients whose veins are no longer as resilient as they once were, where it may be difficult to stretch the saphenous vein graft enough to evert it over a large inner flange. This is also true of many artificial graft materials that will not stretch at all to evert them over a large flange. The anastomosis fitting340 of FIG. 29 A-C has atubular body member341 with a small primaryinner flange342 attached to the distal end.Threads343 or similar features on the inner surface the proximal end of thetubular body member341 facilitate grasping thetubular body member341 with an application instrument. A secondaryinner flange washer344 has acentral orifice345 with inwardly facingtabs346 configured to engage the primaryinner flange342, as seen in distal end view29C. Anouter flange347 is configured to slide over the proximal end of thetubular body341 and is locked in place by a self-lockingretaining washer348 with upwardlyinclined tabs349 that frictionally engage the outer surface of thetubular body341, allowing theouter flange347 to slide in the distal direction with respect to the tubularouter body341, but not in the proximal direction. Theouter flange341 may have a plurality of attachment spikes350 on its distal surface to penetrate theouter wall258 of thetarget vessel255.
• In operation, first the[0165]outer flange347 with its retainingwasher348 and then the secondaryinner flange washer344 are back loaded onto theholder352 of theapplication device351. Next, thetubular body341 is threaded onto the distal end of theholder352. Thegraft vessel254 is passed through theinternal lumen353 of theapplication instrument351 and thedistal end259 of thegraft vessel254 is everted over the small primaryinner flange342 of theanastomosis fitting340. The secondaryinner flange washer344 is then slid distally so that it bears against the proximal face of theinner flange342, as shown in FIG. 29A. The primaryinner flange342, with the evertedgraft vessel259 attached, and the secondaryinner flange washer344 are inserted through anopening267 that has been made in thetarget vessel wall255 as shown in FIG. 29A. A slight tension is exerted on theapplication instrument351 to seat the primaryinner flange342 and the secondaryinner flange washer344 against theinterior surface257 of thetarget vessel wall255 and thedriver354 is advanced distally to press theouter flange347, with its self-lockingretaining washer348, onto the exterior of thetubular body member341 until the desired degree of compression between the inner242,344 and outer flanges is obtained. Theholder352 is disengaged from thetubular body member341 and theentire application instrument351 is withdrawn from the body.
• A distal end view of the completed anastomosis is shown in FIG. 29C. The larger diameter of the secondary[0166]inner flange washer344 adds to the security of the anastomosis attachment while it does not require thegraft vessel254 to be stretched to fit over a large inner flange. Only a very small amount of foreign material is exposed within the target vessel lumen and it is spaced a short distance from the actual anastomosis site which may reduce the likelihood of complications. Because the secondaryinner flange344 washer only contacts the primaryinner flange342 and the evertedgraft vessel wall259 at four small points, it will not interfere with the intima-to-intima approximation of thegraft vessel259 and thetarget vessel255 which is preferred in order to promote endothelialization of the anastomosis site.
• FIGS.[0167]30A-30F illustrate an embodiment of the anastomosis fitting355 of the present invention which combines an innertubular member356 havingdeformable attachment legs357 at its distal end, with anouter flange358. Thedeformable attachment legs357 have aninitial position357 allowing thegraft vessel254 to be easily everted over and penetrated by theattachment legs357. Theattachment legs357 are subsequently deformed to a deployedposition357′ wherein theattachment legs357′ perform the function of the inner flange in many of the above-described embodiments by engaging theinterior surface257 of thetarget vessel255 and compressing the tissue between theattachment legs357′ and the outer flange,358 The innertubular member356 is shown in FIG. 30A. Thetubular member356 is preferably made from a biocompatible metal, such as an alloy of stainless steel, titanium or cobalt. Thetubular member356 has aninternal lumen359 of sufficient size to accommodate the external diameter of thegraft vessel254. Thetubular member356 is made with a plurality ofattachment legs357 extending axially from itsdistal end360. This illustrative embodiment is shown with fourattachment legs357. Other exemplary embodiments may have from three to twelveattachment legs357 depending on the sizes of thegraft vessel254 andtarget vessel255 to be joined. Theattachment legs357 preferably have a width of approximately 0.5-2.0 mm, more preferably about 1.0 mm, and a thickness of approximately 0.1-0.5 mm, more preferably about 0.25 mm. The width and thickness of theattachment legs357 is chosen so that thelegs357 will be relatively rigid when they are in their deployedposition357′, yet they are still easily deformed using the special forming dies369,370,371 provided with the anastomosis system. The distal ends361 of theattachment legs357 are sharpened to easily penetrate the walls of thegraft vessel254 andtarget vessel255. The exterior surface of thetubular member256 may be made with a groove or slot362 around its circumference as a detent for theouter flange358 spaced a calculated distance from thedistal end360 of thetubular member356 to provide a desired degree of compression on the anastomosis when theouter flange358 locks into the groove.362 A plurality ofholes363 through the wall of the tubular member356 (threeholes363 in this illustrative embodiment) are located near the proximal end of thetubular member356 to facilitate grasping thedevice355 with anapplication instrument372.
• The[0168]outer flange358, illustrated in FIG. 30B, has acentral orifice364 which is sized to fit over the exterior of thetubular member356. Theouter flange358 has a locking mechanism, which includes a self-lockingretaining washer365 with upwardlyinclined locking tabs366 integrally formed with the outer flange,358 to sidably position theouter flange358 on the exterior surface of thetubular member356. Alternatively, the self-lockingretaining washer365 can be manufactured separately and attached to theouter flange358 The upwardlyinclined locking tabs366 allow the retainingwasher365 to slide in the distal direction over the exterior of thetubular member356, but resist sliding in the proximal direction. When the upwardlyinclined locking tabs366 lock into thegroove362 in the exterior surface of thetubular body356 it forms a more permanent attachment, strongly resisting movement in the proximal direction. Other locking mechanisms can also be used for positioning theouter flange358 with respect to thetubular member356, such as ratchet mechanisms, detents, or releasable locking devices. Thedistal surface367 of theouter flange358 is configured to contact theexterior surface258 of thetarget vessel255. Preferably, thedistal surface367 of theouter flange358 is slightly concave, as illustrated. If desired, theouter flange358 may be made with short spikes extending from its distal surface. The outer periphery of theouter flange358 is perforated with a series ofholes368, which are positioned to be aligned with the distal ends361′ of theattachment legs357′ of thetubular member356 when the fitting355 is fully deployed. Making theholes368 in a multiple of the number ofattachment legs357, as in the present example which has eightholes368, corresponding with fourattachment legs357, facilitates aligning theholes368 with the distal ends361′ of theattachment legs357′. Theouter flange358 is preferably made from a biocompatible metal, such as an alloy of stainless steel, titanium or cobalt or a biocompatible polymer. Alternatively, aseparate locking washer365 made from a biocompatible metal can be joined to anouter flange358 made of a polymer or other biocompatible material.
• The anastomosis fitting[0169]355 is part of a complete anastomosis system for forming and applying the anastomosis fitting355 to create an end-to-side anastomosis. A set of three forming dies369,370,371 are configured to deform theattachment legs357 of the anastomosis fitting355 from theirinitial position357 to a deployedposition357′, and a specializedgrasping tool372 is used to insert the deployed innertubular member356 through anopening267 in the side wall of thetarget vessel355. These tools, which will be described in more detail in the operational description below, facilitate the rapid and repeatable deployment of the anastomosis fitting355 with a minimum of manual manipulation required.
• In operation, the end-to-side anastomosis procedure is performed using the anastomosis fitting[0170]355 by first preparing thefree end259 of thegraft vessel254 for attachment. If the anastomosis being performed is a second anastomosis or is being performed on the free end of a pedicled graft, theouter flange358 must first be back-loaded onto thegraft vessel254 with thedistal surface367 facing theend259 of the vessel to be attached. If the anastomosis is being performed as the first anastomosis on a free graft, theouter flange358 can be backloaded onto thecraft vessel254 at this time or it can be passed overgraft vessel254 from the far end at a later point in the procedure, whichever is preferable. Next, thefree end259 of thegraft vessel254 is passed through theinternal lumen359 of the innertubular member356 so that it extends a short distance from thedistal end360 of thetubular member356, as shown in FIG. 30C. Thefree end259 of thegraft vessel254 is everted and theattachment legs357 are pierced through the evertedwall259 of thegraft vessel254 to prepare thegraft vessel254 as shown in FIG. 30D. If desired, a loop of suture can be tied around theeverted end259 of thegraft vessel254 to help secure thegraft vessel254 in its everted position over the exterior surface of thetubular member356.
• After piercing the[0171]graft vessel wall259, theattachment legs357 of thetubular member356 are deformed from theiraxially extending position357 by first bending them outward so that they extend radially from thedistal end360 of thetubular member356, then bending the distal ends361′ of each of theattachment legs357′ so that they are directed proximally with respect to thetubular member356, as shown in FIG. 30E. For a typical application of the anastomosis fitting355 in making an end-to-side anastomosis between a saphenous vein graft and the ascending aorta, theradially extending portion373 of each deployedattachment leg357′ is about 3-4 mm long, and the proximally directeddistal portion374 of each deployedattachment leg357′ is about 2-5 mm long. These dimensions will vary somewhat depending on the size and the wall thickness of the graft vessel and the target vessel to be joined.
• A set of three forming dies[0172]369,370,371 are provided for rapidly and repeatably forming the anastomosis fitting355 into the deployed position shown in FIG. 30E. Thefirst die369 is cylindrical in shape with a counterbored recess375 on one end which is sized to hold the proximal end of thetubular member356 of the anastomosis fitting. An annular formingsurface376 on the end of the die369 surrounds the counterbored recess375. Anannular space377 between the counterbored recess375 and the annular formingsurface376 provides sufficient clearance for theeverted end259 of thegraft vessel254 when the innertubular member356 of the anastomosis fitting355 is inserted into the counterbored recess375. The proximal end of thegraft vessel354 extends through acentral lumen378 in thefirst die369 and exits the die through anotch379 in the far end of thedie369 which communicates with thelumen378. Thesecond die370 has a conicallytapered end380 which is used to initiate the outward bend of theattachment legs357 by pressing thetapered end380 between theattachment legs357, as shown in FIG. 30G. Thethird die371 is cylindrical in shape with acounterbore381 on one end that is sized to fit over the outside of thefirst die369 with a radial clearance sufficient for the thickness of theattachment legs357′. There is a formingshoulder382 within thecounterbore381 of thethird die371, and there is atapered edge383 leading into thecounterbore381. Thethird die371 is placed over the distal end of the innertubular member356 after theattachment legs357 have been bent outward by thesecond die370. As thecounterbore381 of thethird die371 slides over the exterior of the first die,369 theradially extending portion373 of theattachment legs373 are formed between the formingshoulder382 of thethird die371 and the annular formingsurface376 of thefirst die369 and theproximally extending portion374 of theattachment legs357′ is formed between the exterior of thefirst die369 and thecounterbore381 of thethird die371, as shown in FIG. 30H.
• The[0173]tubular member356 of the anastomosis fitting355, which has been formed to its deployed position, is withdrawn from thefirst die369 and is grasped with the specialgrasping tool372. The graspingtool372 hasexpandable jaws384,385 which fit between thegraft vessel354 and theinner lumen359 of thetubular member356. Thejaws384,385 are shaped like sectors of a cylinder with an exterior diameter approximately equal to the inner diameter of thetubular member356. Each of the sectors is somewhat smaller than a semicylinder so that thejaws384,385 can be collapsed small enough to easily fit within theinternal lumen359 oftubular member357. A thumbscrew, or other suitable mechanism, on the graspingtool372 expands thejaws384,385 so that they bear against the interior surface of thetubular member356.Lugs386 corresponding to the threeholes363 in the proximal end of thetubular member356 engage the threeholes363 to enhance the grasping tool's grip on thetubular member356.
• Using the grasping[0174]tool382, thebent attachment legs357′ and thedistal end360 of the tubular member, with theeverted end259 of thegraft vessel254 attached. are inserted through anopening267 in thetarget vessel wall255 that has previously been made with an aortic punch or similar instrument, as shown in FIG. 30I. Theopening367 is preferably made so that it is approximately the size of the external diameter of thetubular member356 to provide compression around theeverted end259 of thegraft vessel254 to help create an anastomotic seal. Since theopening267 is slightly smaller than the diameter of thebent attachment legs357′, theopening267 must be stretched slightly to allow theattachment legs357′ to pass through theopening267. Insertion can be effectively accomplished by passing two of theattachment legs357′ through theopening267 in thetarget vessel wall255, then gently stretching theopening267 with forceps to insert the remainingattachment legs357′.
• Once the[0175]attachment legs357′ have been passed through theopening267 in thetarget vessel wall255, the innertubular member356 is pulled back with enough force to cause the sharpened distal ends361′ of theattachment legs357′ to pierce theinterior surface257 of thetarget vessel wall255. This action also serves to approximate theeverted end259 of thegraft vessel254 with theinterior surface257 of thetarget vessel255 to effect the desired intimal surface-to-intimal surface approximation between the two vessels. The sharpened distal ends361 of theattachment legs357′ can be assisted in piercing thetarget vessel wall255 by pressing on theexterior258 of thetarget vessel wall255 with an elastomeric-tipped probe while maintaining some tension on thetubular body356 of the fitting using the graspingtool372. The anastomosis is completed by sliding thecentral orifice364 of theouter flange358 over the exterior surface of thetubular member356 and moving theouter flange358 distally while keeping some tension on thetubular member356 to create tissue compression at the anastomosis site to assure an anastomotic seal. Aprobe387 with a distal pushingsurface388 can be used to press theouter flange358 onto thetubular member356. The distal pushingsurface388 of theprobe387 is slotted and and led so that it can be used from the side of the graspingtool372. The proximally directeddistal ends361′ of theattachment legs357′ pass through theholes363 around the periphery of theouter flange358, as shown in FIG. 30J. If desired, thedistal surface367 of theouter flange358 can be made somewhat concave to help create a hemodynamically efficient transition between thetarget vessel lumen256 and thegraft vessel lumen249. The self-lockingretaining washer365 of theouter flange358 locks into thecircumferential groove362 on the exterior of thetubular member356 to permanently hold theouter flange358 in a fixed position relative to thetubular member356.
• FIG. 31A shows a further embodiment of an[0176]anastomosis device390 according to the invention that combines afastening flange391 with a plurality ofstaple members392. Thedevice390 includes afastening flange391 which has acentral orifice393 of sufficient size to accommodate the external diameter of thegraft vessel254. The external diameter of a saphenous vein graft used in CABG surgery can range from 3 to 10 mm. Thefastening flange391 and thecentral orifice393 can be made circular, as shown in FIG. 31B, for making a typical right angle anastomosis. Alternatively, thefastening flange391 and/or thecentral orifice393 can be made elliptical, oval, egg-shaped or tear drop shaped, as shown in FIGS. 31C and 31D, for making a more hemodynamically efficient angled Anastomosis. Many of the anastomotic fittings and staples described herein lend themselves to noncircular configurations, such as elliptical or teardrop shapes. Each of the detailed descriptions of the various embodiments should be assumed to include noncircuiar flanges as an optional configuration. Thefastening flange391 is made with adistal surface394 over which thefree end259 of thegraft vessel254 is everted, as shown in FIG. 31A. Thefastening flange391 can be made with anannular ridge395 or with other features on its outer surface to help attach theeverted end259 of thegraft vessel254 to theflange391. Thedistal surface394 of thefastening flange391 may be contoured to provide a close fit between theeverted edge259 of thegraft vessel254 and theexterior wall258 of thetarget vessel255. If thetarget vessel254 diameter is very large compared to the diameter of thegraft vessel254, as in a coronary artery bypass graft to ascending aorta anastomosis, then a planardistal surface394 on thefastening flange391 may sufficiently approximate theexterior surface258 of thetarget vessel255. However, if thegraft vessel254 diameter is closer to the diameter of thetarget vessel255, as in a bypass graft to coronary arterv anastomosis, then thefastening flange391 should be made with a cylindrical or saddle-shaped contour on thedistal surface394 that closely approximates the exterior contour of thetarget vessel255. Thefastening flange391 should be made of a biocompatible material such as stainless steel, titanium alloys, or a biocompatible polymer. Thefastening flange391 acts as an external stent which holds the anastomosis site open and patent, so the flange material is preferably rigid or at least sufficiently resilient to hold its intended shape.
• The[0177]fastening flange391 with theeverted end259 of thegraft vessel254 attached to it is fastened to theexterior wall258 of thetarget vessel255 with thecentral orifice393 aligned with anopening267 in thetarget vessel wall255 that has been previously made using a vessel punch or similar instrument. Thefastening flange391 is held in place by a plurality offastening members292, which in this embodiment take the form of metallicsurgical staples292 which are shown in FIG. 31E. Thesurgical staples292, preferably 4-12 of them arranged around the periphery of thefastening flange391, traverse from theproximal side396 to thedistal side394 of theflange391, then pierce the evertedgraft vessel wail259 and the wall of thetarget vessel255. It is preferable that thestaples292 pass through premadeholes397 in thefastening flange391, however, if thefastening flange391 is made of a resilient material, thestaples392 may pierce theflange391 as they pass through it. The distal ends398 of thestaples392 are deformed by a forming device or anvil against theinterior surface257 of thetarget vessel wall255 to hold the device in place to complete the anastomosis.
• The[0178]staples392 can be specially constructed so that they will deform at the appropriate point on theattachment legs399. One way to achieve this desired result is to make thecore400 of thestaple392, including thecrossbar401 and the twoattachment legs399, of a soft deformable metal such as annealed stainless steel. A proximal portion of each of theattachment legs399 is surrounded by astiffening sleeve402 that is made of a more rigid material, such as hard stainless steel hypodermic tubing. The stiffeningsleeves402 prevent the proximal portion of theattachment legs392 from deforming. The stiffeningsleeves402 should be sized so that their length corresponds to slightly less than the combined thickness of theflange391, thegraft vessel wall259 and thetarget vessel wall255 so that, when theattachment legs399 are bent at the distal edge of the stiffeningsleeves402, a tailored amount of compression is applied at the anastomotic site to ensure a leak proof attachment without excessive crushing of the tissue which could lead to necrosis. Alternatively, the staples could be manufactured withattachment legs399 having a thicker cross section proximal portion and a thinner cross section distal portion so that theattachment legs399 will deform at the appropriate point.
• The[0179]anastomosis device390 is part of a complete anastomosis system that includes a specially adapted application device403 for creating the anastomosis. The distal end of the application device403 can be seen in FIG. 31A. Astaple driver404 pushes thestaples392 from the proximal end, while a specially constructedanvil405 reaches into thelumen256 of thetarget vessel255 to deform the distal ends398 of theattachment legs399. Thestaple driver404 has an annulardistal surface406 which presses against thecrossbars401 of thestaples392. In one embodiment, thestaple driver404 can be tubular with aninternal lumen407 large enough to accommodate thegraft vessel254, allowing thecraft vessel254 to be passed through thestaple driver404 from the proximal end to the distal end. Alternatively, thestaple driver404 can be made with a C-shaped cross section with a side opening that is large enough to pass the graft vessel through from the side. Theanvil405 is articulated on the distal end of anelongated shaft408. Theshaft408 is long and narrow enough to pass through thelumen249 of thegraft vessel254 from the free end of the graft. Theanvil405 is passed through thegraft vessel lumen249 in an orientation axially aligned with of theshaft408 and, once it is in thelumen256 of thetarget vessel255, it is articulated at 90°, as shown in FIG. 31A. A cylindrical or olive-shaped centeringelement409, such as an inflatable centering balloon on theshaft408, can be used to center theshaft408 of theanvil405 within thelumen249 of thegraft vessel254 and within thecentral orifice393 of the flange291. Theanvil305 can now be rotated about theshaft308 to deform the distal ends398 of theattachment leas399.
• The application device[0180]403 can operate by two different mechanisms. It can operate in a manner similar to other surgical staplers by aligning thestaple driver404 and theanvil405 on opposite ends of astaple292, then moving them axially toward one another, by moving either thestaple driver404 distally, or theanvil405 proximally, or a combination of the two motions. This relative movement compresses thestaple leg399 in between theanvil405 and thestaple driver404 and deforms it to hold the anastomosis together. An alternative mechanism involves rotating theanvil405 with respect to thestaple driver404 and theanastomosis device390 like a wiper to sequentially bend over the distal ends398 of thestaples392, as shown in FIG. 31F. Thestaple driver404 may be equipped with a gripping means for holding thefastening flange391 to prevent any resultant torque on theflange391 from being transferred to the delicate vascular tissues. Alternatively, the olive-shaped centeringelement409 or balloon could have sufficient bearing surface that the delicate vascular tissues do not suffer any significant damage. An alternative embodiment would have two or morewiper anvil elements405 spaced symmetrically about the axis of theshaft408, so that opposingstaples392 are bent simultaneously, reducing the net torque applied to the centeringelement409 and the tissues.
• FIG. 32A shows another variation of the anastomosis device of FIG. 31A. This variation of the[0181]anastomosis device410 uses preformed spring-like fastening staples411. As in the previously described device, theanastomosis device410 includes afastening flange412 with acentral orifice413 of sufficient size to accommodate the exterior diameter of thegraft vessel254. A plurality of preformedfastening staples411 are arranged around the periphery of thefastening flange412. Preferably, thestaples411 are preloaded into premadeaxial holes414 through thefastening flange412. Thestaples411 should be made of a highly resilient biocompatible spring material, such as spring-tempered stainless steel or titanium alloys. Superelastic materials, such as nickel-titanium alloys, can also be used for forming the spring-like staples. Information about the composition and treatment of superelastic metal alloys useful in the manufacture of the spring like staples can be found in U.S. Pat. No. 4,665,906, entitled Medical Devices Incorporating SIM Alloy Elements, the entire disclosure of which is hereby incorporated by reference. Two alternate forms for the spring-like staples411,420 are shown in FIGS. 32B and 32C. FIG. 32B shows asingle staple411 which has oneattachment leg415. Thedistal end416 of theattachment leg415 is sharpened to easily pierce the blood vessel walls. Adistal portion417 of theattachment leg415 is bent at an acute angle with respect to acentral portion418 of theleg415. Similarly, aproximal portion419 of theleg415 is bent at an acute angle with respect to thecentral portion418. Theproximal portion419 and thedistal portion417 of the staple411 can be angled in the same direction with respect to thecentral portion418 to make a C-shaped staple, as shown in FIG. 32B, or the proximal419 and distal417 portions can be angled in opposite directions to create a Z-shaped staple. FIG. 32C shows adouble staple420 which has twoparallel attachment legs415. Thedistal end415 of eachattachment leg415 is sharpened to easily pierce the blood vessel walls. Thedistal portions417 of theattachment legs415 are bent at an acute angle with respect to thecentral portions418 of thelegs415. Theproximal portions419 of thelegs415 are also bent at an acute angle with respect to thecentral portions418. Theproximal portions419 of theattachment legs415 are linked together by acrossbar421. Thedouble staple420 has an advantage in that thecrossbar421 linking the twoattachment legs415 keeps the staple420 aligned within thefastening flange412. When usingdouble staples420 with thefastening flange412, theaxial holes414 through theflange412 should be made as pairs ofholes414 spaced apart by approximately the length of thecrossbar421 of thestaple420. Similar to thesingle staple411 of FIG. 32B, thedouble staple420 can be made with theproximal portions419 and thedistal portions417 of theattachment legs415 angled in the same direction with respect to thecentral portions418 to make a C-shaped staple, when viewed from the side, or the proximal419 and distal417 portions can be angled in opposite directions to create a Z-shaped staple as shown in FIG. 32C.
• The operation of either staple version can be understood from the sequence of drawings in FIGS. 32D, 32E, and[0182]32F. The following operational description using thesingle staple411 of FIG. 32B is, therefore equally applicable to thedouble staple420 of FIG. 32C. Thestaples411 are preferably preloaded into thefastening flange412 so that thedistal bend427 of thestaple legs415 is captured within and straightened by thehole414 through theflange412. The resilience of the spring material prevents thestaple legs415 from taking a permanent set when they are straightened out to load them into theholes414 in theflange412.
• If a superelastic nickel-titanium alloy is used for the spring-[0183]like staples411, then the shape-memory property of the alloy can be used to facilitate loading thestaples411 into theflange412. To do this, thestaple411 would first be annealed in the desired shape for the final staple. Then, thestaple411 would be plastically deformed below its transition temperature to straighten out thedistal bend427. The straightenedstaples411 are easily inserted into theholes414 in theflange412. Finally, thestaples411 are heated above their shape-memory transition temperature to make them resume their annealed shape. Preferably, the transition temperature is below body temperature so that the alloy of thestaple411 is in its martensitic or superelastic phase when thestaple411 is deployed within the body. Since thedistal bend427 is captured within thehole414 in theflange412, it is held straight until thestaple411 is deployed in the following steps.
• The[0184]free end259 of thegraft vessel254 is everted over thedistal surface422 of thefastening flange412, as shown in FIG. 32D, and thedevice410 is aligned with anopening167 that has been previously made in thetarget vessel wall255. To help align thecentral orifice413 of theflange412 with theopening267 in thetarget vessel255, analignment device423 can be inserted through thelumen249 of thegraft vessel254 from the opposite end of the graft. Thealignment device423 has a narrow,elongated shaft424 which fits through thelumen249 of thegraft vessel254 and an atraumatic centeringelement425, such as an inflatable centering balloon on the distal end of theshaft424. The centeringelement425 serves to align thecentral orifice413 of theflange412 and thegraft vessel lumen249 with theopening267 in the wall of thegraft vessel255. Thealignment device425 can also be used to apply a mild amount of traction on thetarget vessel wall255 to better approximate theeverted end259 of thegraft vessel254 and thetarget vessel255 when making the anastomosis. Alternatively, the centeringelement425 could be replaced with a vessel punch introduced through thegraft vessel lumen249, as in the embodiments described in connection with FIGS.2-5.
• Once the[0185]everted end259 of thegraft vessel254 and thetarget vessel255 have been properly approximated, thestaple driver426 is advanced distally, as shown in FIG. 32E. The distal ends416 of thestaples411 pierce the evertedgraft vessel wall259 and thetarget vessel wall255 and thedistal portion417 of theattachment legs415 traverses the vessel walls in a linear path. As thedistal bend427 of theattachment legs415 exit thehole414 in thefastening flange412, thedistal portions417 begin to resume their acute angle bend. By the time thestaple driver426 reaches its most distal position, thedistal bend427 of theattachment legs415 is fully reconstituted within thelumen256 of thetarget vessel255. When thestaple driver426 is withdrawn, the spring action of theproximal bend428 in theattachment legs415 pulls the staple411 back slightly to embed thedistal portions417 of theattachment legs415 into theinterior surface257 of thetarget vessel wall255, as shown in FIG. 32F. The spring action of thestaples411 also serves to exert compressive force between thefastening flange412 and thetarget vessel wall255 to assure a leak proof and secure attachment.
• During the manufacture of the[0186]staples411, thedistal bends427 on thestaple attachment legs415 can be made with almost any desired orientation. The distal bends427 can be oriented to turn thedistal portion417 of theattachment legs415 toward theopening267 in thetarget vessel wall255, as shown in FIG. 32F, or thedistal portions417 can be oriented pointing away from theopening267. Alternatively, thedistal portions417 can be aligned so that they bend tangentially to theopening267. The tangential distal portions can be oriented so that they cross one another. Perhaps more advantageously, the tangentialdistal portions417 can be oriented so that they all bend in the same direction, as shown in FIGS.32G, so that a more complete gap-free seal is made all around the periphery of the anastomosis.
• FIGS.[0187]33A-33D and34A-34D show two variations of ananastomosis device430 having afastening flange431 and a plurality of S-shapedstaple members432 formed from a superelastic metal alloy such as a nickel-titanium alloy. Thefastening flange431 has acentral orifice433 which is sized to accommodate the exterior diameter of thegraft vessel254. Thefastening flange431 has an annulardistal ridge434 and an annularproximal ridge435 around its outer surface. There are a plurality ofholes436 arranged in a circle around the periphery of thecentral orifice433 of theflange431 passing through theflange431 from the proximal surface to thedistal surface438. Each of theholes436 is sized to slidably receive one of the S-shapedstaple members432. There are a plurality ofcylindrical legs439 extending from theproximal surface437 of theflange431. Preferably, thelegs439 are arranged in a circle concentric with thecentral orifice433 and there are an equal number oflugs439 to the number ofholes436 in theflange431 with thelugs439 spaced equidistant fromadjacent holes436.
• The S-shaped superelastic[0188]alloy staple members432 are shown in perspective FIG. 33D. Thestaple member432 is formed with a straightcentral segment440 that is attached to a hook-shapeddistal segment441 and aproximal segment442 which bends at an angle just under 90 degrees from thecentral segment440 in a plane that is approximately at a right angle to the plane defined by the hook-shapeddistal segment441. Thedistal tip443 of the hook-shapeddistal segment441 is sharpened to easily penetrate thegraft vessel wall254 and thetarget vessel wall255. FIG. 34D shows a slight variation of thestaple member432 of FIG. 33D. This variation differs from the previous one in that thedistal segment444 is bent at an acute angle to the central segment rather than being a fully formed hook. The S-shapedstaples432 are annealed in the desired configuration so that they will retain the annealed shape. The extremely resilient nature of the superelastic alloy allows thestaple members432 to be completely straightened without causing plastic deformation of the staples so that they will return to their annealed shape.
• The[0189]anastomosis device430 is prepared for use by passing thegraft vessel254 through thecentral orifice433 of thefastening flange431 then everting thedistal end259 of thegraft vessel254 over thedistal surface437 of theflange431. Asuture445 can be tied around theeverted end259 of thegraft vessel254 to secure it to theflange431. Thedistal ridge434 of theflange431 prevents the tiedgraft vessel259 from slipping off of theflange431. Next, thestaple members432 are straightened and passed through theholes436 in theflange431 from theproximal surface437 to thedistal surface438. Thedistal curve441 of thestaples432 is restrained in the straightened position by the sliding fit with theholes436 in theflange431. When thestaples432 emerge from thedistal surface438 of theflange431, they pierce the evertedwall259 of thegraft vessel254. At this point thefastening flange431 with theeverted end259 ofcraft vessel254 attached to it is approximated to theexterior surface258 of thetarget vessel255 with thecentral orifice433 and thelumen249 of thegraft vessel254 centered on anopening267 that has been made in the wall of thetarget vessel255. The distal ends443 of thestaple members432 pass through theopening267 in thetarget vessel wall255.
• Once the[0190]graft vessel254 and thetarget vessel255 are properly approximated, anannular staple driver446 is used to push thestaple members432 distally through theholes436 in theflange431 so that they emerge into thelumen256 of thetarget vessel255. As the distal ends443 of thestaple members431 emerge from thedistal surface438 of theflange431 thedistal segments441 resume their annealed shape. The hook-shapeddistal segments441 of thestaple members431 in FIG. 33D curve back toward theinterior surface257 of the target vessel and penetrate thetarget vessel wall255. Theproximal segments442 of thestaple members432 are positioned between thelugs439 on theproximal surface437 of theflange431 to lock thestaples432 from rotating with respect to theflange431. FIG. 33C shows a proximal view of theanastomosis device430 with thestaple members432 deployed. This view is shown without the graft vessel or the target vessel present for the sake of clarity. As best seen in FIG. 33B, the acute angle of theproximal segment442 acts like a spring to pull back on thestaple member432 to help thedistal segment441 to pierce thetarget vessel wall255 and to help create compression between theflange431 and thetarget vessel wall255 to create a leak proof anastomotic seal between thegraft vessel254 and thetarget vessel255.
• The deployment of the anastomosis device in FIGS.[0191]34A-34D is essentially the same as just described up until the point when the distal ends444 of thestaple members432 begin to emerge into thetarget vessel lumen256. As the distal ends443 of thestaple members432 emerge from thedistal surface438 of thefastening flange431, they resume their acute angle bend. Rather than penetrating thetarget vessel wall255, thedistal segments444 of thestaple member432 align themselves flat against theinterior surface257 of thetarget vessel255 and press against thevessel wall255, compressively clamping thefastening flange431 and theeverted end259 of thegraft vessel254 to thetarget vessel wall255. The acute angle of theproximal segment442 acts like a spring to pull back on thestaple member432 to keep thedistal segment444 snug against theinterior surface257 of thetarget vessel wall255.
• FIGS.[0192]35A-35F show another variation of ananastomosis device447 using afastening flange448 andattachment staple449 combination. Thefastening flange448 is a cylindrical member with aninternal lumen450 large enough to accommodate the external diameter of thegraft vessel254. Theflange448 has a distal surface451 over which thefree end254 of thegraft vessel259 may be everted. Anannular ridge452 around the outer surface of theflange448 at the distal end helps to hold the evertedgraft vessel259 in place and serves as part of a locking mechanism for theattachment staples449, as will be described below. Theattachment staples449 are in the form of U-shaped hooks withbarbed points453 on their distal tips. Eachstaple449 has aproximal portion454 which is slidably received within anaxial hole456 through thecylindrical wall457 of thefastening flange448. Theproximal end455 of theproximal portion454 is sharpened for easily piercing the tissue of thegraft vessel wall254. AU-shaped bend458 connects theproximal portion454 of the staple449 to the barbed, pointeddistal portion453.
• The[0193]anastomosis device447 is applied by removing theU-shaped staples449 from theflange448. Theend259 of thegraft vessel254 is passed through theinternal lumen450 of theflange448 until thegraft vessel254 extends a short distance from thedistal end459 of theflange448. Then, theend259 of thegraft vessel254 is everted back over thedistal end259 of theflange448. Once thegraft vessel254 is everted over theflange448, thestaples449 are reinserted into theholes456 in theflange458 by piercing theproximal end445 through the evertedwall259 of thegraft vessel254. Marks or other visual indications can be provided on the side of thecylindrical flange448 to aid in aligning the proximal ends455 of thestaples449 with theholes456. Theproximal portions454 of thestaples449 are partially advanced into theflange448 as shown in FIG. 35B. The U-shaped ends458 of thestaples449 are inserted through anopening267 in the wall of thetarget vessel255 which has previously been made using a vessel punch or similar instrument. Two alternate methods can be used for inserting thestaples449 through theopening267 in thetarget vessel wall255. In the first method, shown in FIG. 35C, the U-shaped ends458 of the staples are extended from thecylindrical flange448 far enough that they easily deflect inward toward the center of theopening267 in thetarget vessel wall255 when they contact the edge of theopening267 so that they can be simultaneously inserted through theopening267. In the second method, the U-shaped ends458 of thestaples449 are rotated, as shown in FIG. 35D, so that the U-shaped ends458 all fit within a circle that will pass through theopening267 in thetarget vessel wall255. Once the U-shaped ends458 of thestaples449 are within thelumen256 of thetarget vessel255, thestaples449 can be rotated so that the U-shaped ends458 extend radially outward from thefastening flange448. Thedistal surface459 of thecylindrical flange448 with the evertedgraft vessel259 attached to it is approximated to theexterior surface258 of thetarget vessel255, then thestaples449 are withdrawn in the proximal direction so that the barbed, pointeddistal ends453 pierce thetarget vessel wall255. Thedistal portion460 of the staple449 passes through thetarget vessel255 wall in a linear path, then pierces the evertededge259 of the graft vessel wall254 a second time. When thebarbed end453 ofstaples449 pass theannular ridge452 on thedistal end459 of theflange448 thebarbs453 engage the proximal surface of theridge452, locking thestaples448 in position to permanently attach theanastomotic device447 in place. The excess length on theproximal portion454 of theU-shaped staples449 may be cut off flush with theproximal end461 of thecylindrical flange448. Alternatively, theproximal portion454 of the staple449 can be bent over at theproximal end461 of thecylindrical flange448 for a second means of attachment, then the excess length cut off.
• Two alternative versions of the anastomosis device of FIG. 35A, using different locking means for the U-shaped staples, are shown in FIGS.[0194]36A-36C and37A-37C. FIG. 36A shows ananastomosis device462 with afastening flange463 and a plurality of non-barbedU-shaped staples464 and alocking collar465 for locking theU-shaped staples464 onto thefastening flange463. Theflange463 and thestaples464 are applied in much the same way as described above for the previous embodiment, by inserting thestaples464 through theopening267 in thetarget vessel255 and withdrawing them in the proximal direction so that the distal ends466 of thestaples464 pierce thetarget vessel wall255 and emerge alongside the outer surface of thefastening flange463. Alocking collar465 is then pressed onto theproximal end467 of thefastening flange463, as shown in FIG. 36B, crimping the distal ends466 of thestaples464 and locking them to theflange463 in the process. The excess length of theproximal portion468 of thestaples464 is cut off flush with theproximal end467 of thefastening flange463 to complete the anastomosis, as shown in FIG. 36C.
• FIG. 37A shows a second anastomosis fitting[0195]469 with non-barbedU-shaped staples470 and alocking collar471 for locking the U-shaped staples onto thefastening flange472 of the fitting469. Thefastening flange472 in this embodiment has aconical surface473 on the outer surface of theflange472 proximal to thedistal rim474 of theflange472. Theproximal end475 of thefastening flange472 has a series of parallel annular lockingridges476 around its exterior surface. Alocking collar471 has aninterior taper477 which matches theconical taper473 of thefastening flange472 and a series ofparallel locking ridges478 on the proximal end. After theflange472 and thestaples470 have been applied as described above, thelocking collar471 is pressed onto theflange472, as in FIG. 37B. The distal portion479 of theU-shaped staple470 is wedged between the mating conical tapers473,477. The lockingridges478 of thelocking collar471 engage the lockingridges476 of theflange472 to permanently lock theanastomosis device469 in place and the anastomosis is completed by cutting off theproximal portions480 of thestaples470 flush with the proximal end of theflange475, as shown in FIG. 37C.
• The anastomosis fittings of FIGS.[0196]33-37 may also be manufactured using staple elements made of a highly elastic material, such as a superelastic nickel-titanium alloy, so that the staples may be preformed with U-shaped ends which can be straightened and loaded into the holes in the fastening flange. The staples would be deployed by pushing them out the distal end of the flange so that they pass through the wall of the graft vessel into the target vessel, after which, they resume their U shape within the lumen of the target vessel. The highly elastic staple elements could be locked onto the fastening flange using any of the methods described in connection with FIGS.33-37.
• FIGS.[0197]38A-38C and39A-39C show one-piece versions of an anastomosis device using a fastening flange and attachment staple combination. FIG. 38A shows ananastomosis device481 that has afastening flange482 and integrally formedstaple members483. Thefastening flange482 is a flat annular ring which may be formed from a flat sheet of a biocompatible metal. Thestaple members483, which may be formed from the same sheet of metal, attach to theinner diameter484 of thering482 and are initially bent 90° from theflange482 so that they extend in the distal direction, as shown in FIG. 38B. Theinner diameter484 of the flange fits over a tubularinner member485 of anapplication tool486. Thegraft vessel254 is passed through aninner lumen487 within thetubular member485 and then theend259 of thegraft vessel254 is everted over thedistal end488 of thetubular member485. Theapplication tool486 is used to approximate theend259 of thegraft vessel254 to anopening267 that has previously been made in the wall of thetarget vessel255. Atubular staple driver489 slides telescopically over the exterior of the tubularinner member485. Thefastening flange482 is moved distally by sliding thestaple driver489 axially with respect to the innertubular member485, which forces the sharpened distal ends490 of the integralstaple legs483 through the evertedwall259 of thegraft vessel254 and the wall of thetarget vessel255. Once thestaple legs483 have traversed thegraft vessel254 andtarget vessel walls255, the distal ends490 of thestaple legs483 are deformed to lock theanastomosis device481 in place as shown in FIG. 38C.
• Different methods can be used for deforming the distal ends[0198]490 of thestaple legs483 to attach theanastomosis device481. An articulating anvil, similar to the one described in FIG. 31A can be inserted through thelumen249 of thegraft vessel254 to work cooperatively with thestaple driver489 to deform the distal ends490 of thestaple legs483. Alternatively, thefastening flange482 and thestaple legs483 can be made of a spring-like elastic or superelastic alloy and preformed into their final desired shape. The innertubular member485 of thestaple application device486 seen in FIG. 38B holds the preformed distal bend491 in thestaple legs483 straight until theanastomosis device481 is deployed by thestaple driver489. Another alternative is to make theanastomosis device481 and thestaple legs483 from a shape-memory alloy, such as a nickel-titanium. Thestaple legs483 are annealed in their final shape. Then, thestaple legs483 are plastically deformed below the material's transition temperature to straighten out the distal bends491. The straightenedstaple legs483 are driven through the walls of thegraft vessel254 and thetarget vessel255 and thestaple legs483 are heated above their shape-memory transition temperature to make them resume their annealed shape. The material is preferably chosen so that the transition temperature is at or near body temperature so that heating the staple above the transition temperature does not cause damage to the delicate vascular tissues.
• FIG. 39A shows an[0199]additional anastomosis device492 that has afastening flange493 and integrally formedstaple members494. Thefastening flange493 in this case is a cylindrical ring formed from a tube of a biocompatible metal. Thestaple members494 are attached to the distal edge of thecylindrical fastening flange493. Optionally, there are also proximal fastening members attached to the proximal edge of thecylindrical fastening flange493. This variation of the anastomosis device can be applied with any of the methods just described in connection with FIGS.37A-37C. If theanastomosis device492 has been made of an elastic or superelastic alloy, the optionalproximal fastening members495 can serve as spring members to compress the anastomotic attachment, similar to the proximal portions of the spring-like staples411,420 described in connection with FIGS.32A-32F.
• FIGS.[0200]40A-40D show a two-piece version of an anastomosis device496 having a fastening flange and integrally formed staple members. In this case, the fastening flange of the device is formed of two concentric cylindrical flange rings497,498. A plurality of interlockingstaple members499,500 extend from the distal edges of both cylindrical flange rings497,498. Preferably, thestaple members499,500 are integrally formed with the cylindrical flange rings497,498. Thestaple members499 of theinner flange ring497 are angled so that they spiral downward from thering497 in a clockwise direction. Thestaple members500 of theouter flange ring498 are oppositely angled so that they spiral downward from thering497 in a counterclockwise direction. Corresponding locking features501,502 on the inner surface of theouter flange ring498 and on the outer surface of theinner flange ring497 are capable of locking the two flange rings498,497 together in a fixed position. Indentations on one flange ring, with corresponding detents on the other flange ring are one of the many possibilities for the locking features501,502.
• The anastomosis device[0201]496 is applied by separately placing first theouter flange ring498, then theinner flange ring497 around thedistal end259 of thegraft vessel254. Theend259 of thegraft vessel254 is then everted and approximated to theexterior wall258 of thetarget vessel255 surrounding anopening267 which has been previously made in the wall, as shown in FIG. 40C. Theinner ring497 is moved distally along thegraft vessel497 until the points of thestaple members499 contact the evertedvessel wall259. Theinner ring497 is pressed into the evertedgraft vessel wall259 and simultaneously rotated in a clockwise direction, thereby driving thestaple members497 through thegraft vessel wall259 and thetarget vessel wall255. Next, theouter ring498 is moved distally along thegraft vessel254 until it is concentric with theinner ring497. Then theouter ring498 is pressed into the evertedgraft vessel wall259 and simultaneously rotated in a counterclockwise direction, driving thestaple members500 through thegraft vessel wall259 and thetarget vessel wall255. When the locking features501 of theouter ring498 coincide with the locking features502 of theinner ring497, the outer498 and inner497 rings become locked together. As the flange rings497,498 are rotated in opposite directions, thestaple members499,500 of the inner497 andouter rings498 penetrate the vessel walls in opposite directions as shown in FIG. 40C, effectively locking the anastomosis device496 to theexterior258 of thetarget vessel255.
• Alternatively, the inner[0202]497 andouter rings498 of the flange can be applied simultaneously to theeverted end259 of thegraft vessel254 by arranging therings497,498 concentrically, then pressing thestaple members499,500 into thegraft vessel wall259 while counter-rotating the inner497 and outer498 rings. This could best be done with an instrument that holds and rotates the inner497 and outer498 rings mechanically.
• FIGS.[0203]41A-41E show another approach to making ananastomosis device503 having afastening flange504 and a plurality ofindividual staple members505. The method of deployment used in this embodiment allows thestaple members505 to be made of a normally elastic metal alloy, such as spring-tempered stainless steel. Thefastening flange504 in this embodiment is a tubular element with acentral orifice506 which is surrounded by aninner wall507, adistal surface508, and anouter wall509 defining anannular space510 between the inner507 andouter walls509. The annular distal surface interconnects the inner507 and outer509 walls. Theannular space510 is sized to fit thestaple members505 prior to deployment, as shown in FIG. 41A. Astaple application tool511 has anannular staple driver512 which fits into theannular space510 within theflange504. Thedistal surface508 and theinner wall507 of theflange504 is slotted with pairs of L-shapedslots513 to allow penetration of thestaple members505 through thedistal surface508.
• Alternatively, the[0204]flange504 may have a solid body and theannular space510 can be replaced by a series of individual staple slots formed in the body of the flange by a process like electrical discharge machining. The individual staple slots can each be sized to fit asingle staple member505. Each individual staple slot should communicate with a single slot or a pair of slots in thedistal surface508 of thefastening flange504 for proper deployment of thestaple members505, depending on whether the staple members are single or double-leg staples. In this case, theannular staple driver512 of theapplication tool511 must be replaced with an array of individual staple drivers sized to fit into the individual staple slots.
• The[0205]staple members505 for this embodiment can be made as J-shaped, single-leg staples505′ or as U-shaped, double-leg staples505. When viewed from the side, the single505′ and double-leg staples505 are both roughly the shape of an inverted J, as seen in FIG. 41A. The double-leg staples505 combine two such J-shaped staple legs514 with acrossbar515 that connects the proximal ends of the staple legs514 to formstaples505 that are roughly U-shaped when viewed from the front or from the top, as in FIG. 41E. The staple legs514 are formed with acentral segment516 that is attached at an acute angle to aproximal segment517. A shortintermediate segment518 may be used to connect theproximal segment517 to thecentral segment516 of thestaple member505. The proximal end of each of theproximal segments517 is joined to thecrossbar515 of thestaple member505. Adistal segment519 is attached to thecentral segment516 at an obtuse angle so that it is approximately parallel to theproximal segment517. Thedistal end520 of thedistal segment519 is sharpened to easily penetrate thegraft vessel wall259.
• The[0206]anastomosis device503 is prepared by passing thegraft vessel254 through thecentral orifice506 of thefastening flange504 and everting it over thedistal surface508 of theflange504. As an alternative to the loop of suture described in previous embodiments of the device, avessel cap521 may be used to secure the evertedgraft vessel259 to thefastening flange509. Thevessel cap521 is a toroidal ring with an L-shaped cross section that fits around the outer diameter of thedistal surface508 of thefastening flange504 and holds theeverted end259 of thegraft vessel254 in place.
• Next, the[0207]fastening flange504 with theeverted end259 of thegraft vessel254 attached is approximated to theexterior258 of thetarget vessel255 with thecentral orifice506 aligned with anopening267 through thetarget vessel wall255, as shown in FIG. 41A. Thestaple driver512 is then advanced in the distal direction to press against the attachment legs514 of thestaple members505 and force the distal ends50 of thestaple members505 through theslots513 in thedistal end508 of thefastening flange504 to pierce thegraft vessel wall259 and enter thetarget vessel lumen256 through theopening267 in thetarget vessel wall255, as shown in FIG. 41B. As thestaple driver512 is advanced further thecrossbar515 of thestaple member505 contacts thedistal wall508 of thefastening flange504 and thestaple member505 begins to rotate about the point of contact, as shown in FIG. 41C. Thedistal segments519 of thestaple members505 capture thetarget vessel wall255 and pull it tight against thedistal surface508 of thefastening flange504, as shown in FIG. 41D, to form a leak proof anastomotic seal between the evertedgraft vessel wall259 and thetarget vessel255.
• FIGS.[0208]42A-42D illustrate another one-piece embodiment of theanastomosis device522 with afastening flange523 and attachedstaple members524. Preferably, theanastomosis device522 is made from a deformable biocompatible metal, such as a stainless steel alloy, a titanium alloy or a cobalt alloy. If desired a surface coating can be applied to the anastomosis device to improve the biocompatibility or other material characteristics.
• In contrast to some of the previously described embodiments, in this version of the[0209]anastomosis device522, thefastening flange523 resides on theinterior surface258, of thetarget vessel wall255 when the anastomosis is completed. To avoid any problems with hemolysis, thrombogenesis or foreign body reactions, the total mass of thefastening flange523 has been reduced to an absolute minimum to reduce the amount of foreign material within thetarget vessel lumen256.
• The[0210]fastening flange523 is in the form of awire ring523 with an internal diameter which when fully extended is just slightly larger than the diameter of thegraft vessel254 and of theopening267 made in thetarget vessel wall255. Initially, thewire ring523 has a rippled wave-like shape to reduce the diameter of thering523 so that it will easily fit through theopening267 in thetarget vessel wall255. A plurality ofstaple members524 extend from thewire ring523 in the proximal direction. In the illustrative embodiment shown in FIG. 42A, there are nine staple members attached to the wirering fastening flange523. Other variations of theanastomosis device522 might typically have from four to twelvestaple members524 depending on the size of the vessels to be joined and the security of attachment required in the particular application. Thestaple members524 can be formed integrally with the wirering fastening flange523 or thestaple members524 could be attached to thering523 by welding or brazing methods. The proximal ends525 of thestaple members524 are sharpened to easily pierce thetarget vessel wall255 and thegraft vessel wall259. Preferably, the proximal ends525 of thestaple members524 havebarbs526 to improve the security of the attachment when the device is deployed.
• The[0211]anastomosis device522 is prepared for use by mounting the device onto the distal end of a specially adaptedapplication instrument527, as shown in FIG. 42B. Thefastening flange523 is mounted onto ananvil528 attached to the distal end of theelongated shaft531 of theapplication instrument527. Thestaple members524 are compressed inward against aconical holder529 attached to theinstrument527 just proximal to theanvil528. Thestaple members524 are held in this compressed position by acap530 which is slidably mounted on theelongated shaft531. Thecap530 moves distally to cover the sharpened, barbed ends525 of thestaple members524 and to hold them against theconical holder529. Theapplication instrument527 is then inserted through thelumen249 of thegraft vessel254. This can be done by inserting the instrument through thegraft vessel lumen249 from the proximal to the distal end of thegraft vessel254, or it can be done by backloading theelongated shaft531 of the instrument into thegraft vessel lumen249 from the distal end to the proximal end, whichever is most convenient in the case. Theanvil528 andholder529 on the distal end of theapplication instrument527 with theanastomosis device522 attached is extended through theopening267 into thelumen256 of thetarget vessel255.
• Next, the[0212]distal end259 of thegraft vessel wall254 is everted against theexterior surface258 of thetarget vessel wall255 with thegraft vessel lumen249 centered on theopening267 in thetarget vessel wall255. Thecap530 is withdrawn from the proximal ends525 of thestaple members524, allowing thestaple members524 to spring outward to their uncompressed position shown by thephantom lines524′ in FIG. 42B. Theapplication instrument527 is then drawn in the proximal direction so that thestaple members524′ pierce thetarget vessel wall255 surrounding theopening267 and theeverted end259 of thegraft vessel254.
• The[0213]application instrument527 has an annular staple former532 which surrounds the outside of thegraft vessel254. Some slight pressure on the evertedgraft vessel wall259 from the annular staple former532 during the piercing step assists in piercing thestaple members524′ through thegraft vessel walls259. Care should be taken not to apply too much pressure with the staple former532 at this point because thestaple members524′ could be prematurely deformed before they have fully traversed the vessel walls. If desired, an annular surface made of a softer material, such as an elastomer, can be provided on theapplication instrument527 to back up the vessel walls as thestaple members524′ pierce through them.
• Once the[0214]staple members524 have fully traversed thetarget vessel wall255 and thecraft vessel wall259, as shown in FIG. 42C, the staple former532 is brought down with greater force while supporting thefastening flange523 with theanvil528. Thestaple members524′ are deformed outward, as shown by the phantom lines524Δ, so that the sharpened, barbed ends525 pierce back through the evertedgraft vessel wall259 and into thetarget vessel wall255 to form a permanent attachment. To complete the anastomosis, theanvil528 is withdrawn through thegraft vessel lumen249. As theanvil528 passes through the wirering fastening flange523, it straightens out the wave-like ripples so that thewire ring533 assumes its full uncompressed diameter, as shown in FIG. 42D. Alternatively, the wirering fastening flange523 can be made of a resilient material so that theflange523 can be compressed and held in a rippled or folded position until it is released within thetarget vessel lumen256, whereupon it will resume its full, expanded diameter. Another alternative construction would be to make the anastomosis device of a shape-memory alloy so that the wirering fastening flange523 can be compressed and inserted through the opening in thetarget vessel267, whereupon it would be returned to its full expanded diameter by heating thedevice522 to a temperature above the shape-memory transition temperature.
• FIGS.[0215]43A-43B,44A-44B, and45A-45E show a complete system for creating an end-to-side vascular anastomosis using ananastomosis device533 with afastening flange534 and a plurality ofstaple members535 made of a highly resilient or superelastic metal. The system includes a specially adaptedapplication instrument536 for applying theanastomosis device533. FIG. 43A shows a top view of thefastening flange534 of theanastomosis device533, FIG. 43B shows thefastening flange534 of FIG. 43A in cross section from the side. Thefastening flange534 is generally cylindrical in shape with acentral orifice537 of sufficient diameter to accommodate the external diameter of thegraft vessel254. Thewall538 of the fastening flange has a plurality ofholes539 extending from theproximal surface540 of the flange to thedistal surface541 of the flange. Preferably there are an even number ofholes539, two for each of thestaple members535, which may number from four to twelve depending on the size of the vessels to be anastomosed. The illustrated embodiment has twelveholes539 to accommodate sixstaple members535. Theholes539 are preferably angled toward thecentral orifice537 from theproximal end540 to thedistal end541 so that they exit thewall538 of theflange534 at the juncture of thedistal surface541 of the flange and the internal surface of thecentral orifice537. In the illustrative embodiment shown in FIGS. 43A and 43B theholes539 are angled at approximately 10 degrees to the longitudinal axis of theflange534. Other angles are also possible, from −10 to +20 degrees from the longitudinal axis of theflange534 Thefastening flange534 has acircumferential notch542 on the exterior of theflange534 close to thedistal end541 of the flange to aid in attachment of thegraft vessel wall254. There is also acircumferential ridge543 around the exterior of thefastening flange534 proximal to thenotch542 to assist in gripping theflange534 for the operation of theapplication tool536.
• FIGS. 44A and 44B show the[0216]staple member535 of theanastomosis device533 in a front view and a side view. Thestaple members535 are preferably formed from wire made of a highly resilient biocompatible metal such as a spring-tempered alloy of stainless steel, titanium, or cobalt, or more preferably of a superelastic metal alloy, such as a nickel—titanium alloy. The wire preferably has a diameter between 0.006 and 0.025 inches, depending on the stiffness of the metal alloy chosen. Nickel—titanium wire with a diameter of 0.010 to 0.012 inches has been found to be very suitable for this application. Thestaple members535 are roughly an inverted U shape when viewed from the front with twoattachment legs544 joined together at their proximal ends by acrossbar545, as shown in FIG. 44A. When viewed from the side as in FIG. 44B, thestaple members535 are roughly J-shaped with the distal ends546 of theattachment legs544 curving back toward the proximal end of thestaple member535. Each of the J-shapedhooks547 ends in a shortstraight section548 with a sharpeneddistal end546 to easily penetrate thegraft vessel259 andtarget vessel255 walls. Thestaple members535 should be annealed or cold worked in the illustrated configuration, whichever treatment is most appropriate for the metal alloy chosen, so that the staple member has a permanent elastic memory which makes it return to the treated shape.
• The[0217]holes539 through thefastening flange534 are sized so that there is a close sliding fit between theattachment legs544 of thestaple members535 and the interior of theholes539. Theanastomosis device533 is prepared for use by inserting the twoattachment legs544 of eachstaple member535 into twoadjacent holes539 in thefastening flange534, until the curveddistal portion547 of theattachment legs544 are entirely within theholes539. When inserting thestaple members535, they should be oriented so that the curve of the distal ends547 of theattachment legs544 will be biased outward from thecentral orifice537 of thefastening flange534 when extended distally from theholes539 in theflange534. Because of the close sliding fit, the interior walls of theholes539 constrain the curved distal ends547 of theattachment legs544 in a straight position, as shown in FIG. 43B. The straightproximal portion549 of thestaple members535 extend proximally from theproximal end540 of thefastening flange534 as shown.
• The preparation of the[0218]anastomosis device533 can also be accomplished using the shape-memory property of a nickel—titanium alloy. Thestaple members535 would be formed as shown in FIGS. 44A and 44B and annealed to create a shape-memory. Theattachment legs544 of thestaple members535 are then straightened by cold working them below the transition temperature of the shape-memory alloy. In the straightened condition, the distal ends547 of theattachment lees544 are easily inserted into theholes539 in thefastening flange534. Care must be taken to orient thestaple members535 so that the curve of the distal ends547 of theattachment legs544 will be biased outward from thecentral orifice537 of thefastening flange534. Once all of thestaple members535 have been inserted into theholes539 of thefastening flange534, theentire anastomosis device533 can be warmed above the transition temperature of the shape-memory alloy so that the distal ends547 of theattachment legs544 will try to return to their curved shape. Being constrained by the interior walls of theholes539, theattachment legs544 will remain straight, but they will have an elastic memory that will cause them to resume their curved shape when they are released from the confinement of theholes539.
• With the[0219]anastomosis device533 thus prepared, it is ready to be inserted into theapplication instrument536 which is shown in FIGS.45A-45E. Theapplication instrument536 consists of two separate, but interacting, mechanisms, astapling mechanism550 and apunching mechanism551. Thepunching mechanism551 is sized to be slidingly received within aninternal lumen552 of thestapling mechanism550. Most of the parts of theapplication instrument536, unless otherwise specified, are preferably made of a high-strength, dimensionally stable polymer material, such as acetal, ABS, HDPE, PTFE, etc. Alternatively, theapplication instrument536 could be made from stainless, steel, titanium or other metals, if desired.
• The[0220]stapling mechanism550 has a generallycylindrical holder553 which has aproximal end554 and adistal end555. Aninternal lumen556 extends from theproximal end554 to thedistal end555. Thedistal end555 of theholder553 is adapted to hold thefastening flange534 of theanastomosis device533. A throughhole557 in the distal end of theholder553 is sized to be a light press fit around theproximal end540 of thefastening flange534. Acounterbore558 on the distal end of the throughhole557 fits thecircumferential ridge543 of thefastening flange534 to axially locate thefastening flange534 with respect to theholder553. Astaple driver559, which is generally tubular in shape, is slidably received within theinternal lumen556 in theholder553. Thestaple driver559 has a T-shapedhandle560 attached to its proximal end for operating thestapling mechanism550. The proximal end of thestaple driver559 has a shorttubular extension561 with acircumferential groove562 around the exterior of thetubular extension561. The distal end has an annularstaple driving surface563.
• To insert the[0221]anastomosis device533 into the distal end of thestapling mechanism550, the proximal ends549 of thestaple members535 must be flexed slightly toward the central axis of thefastening flange534 so that they will all fit through the throughhole557 on the distal end of theholder553. Once the proximal ends549 of thestaple members535 have been inserted, the proximal end of thefastening flange540 is inserted into the throughhole557 with thecircumferential ridge543 seated into thecounterbore558.
• The[0222]stapling mechanism550 is now ready for attachment of thegraft vessel254 to thefastening flange534. To begin, thegraft vessel254 is passed through theinternal lumen552 of theholder553 and thestaple driver559. This can be done by tying a suture around one end of thegraft vessel254, passing the suture through thestapling mechanism550 and drawing thegraft vessel254 through. Alternatively, an elongated hook or grasping instrument can be inserted through thelumen552 of thestapling mechanism550 to draw thegraft vessel254 through. Thedistal end259 of thegraft vessel254 is then everted over thedistal end541 of thefastening flange534. If desired, a loop ofsuture564 can be tied around theeverted end259 of thegraft vessel254 at the location of the circumferential notch or groove542 to secure thegraft259 to thefastening flange534. Theproximal end565 of thegraft vessel254 can also be everted and temporarily attached with a loop of suture to theproximal extension561 of thestaple driver559 to make thegraft vessel254 easier to handle.
• At this point, the[0223]vessel punch mechanism551 should be inserted into thestapling mechanism550 through thelumen249 of thegraft vessel254. Thevessel punch mechanism551 consists of ahousing566, acutter567, ananvil568, a clamp569, a clamp knob570 and apunch knob571. Thehousing566 is generally cylindrical in shape. There are twoinner chambers572,573 in the housing which are separated by aninternal wall574. Thedistal chamber572 is sized to have a light press fit over theholder553 of thestapling mechanism550. A pair ofset screws575 in theside wall576 of thedistal chamber572 are provided to secure thehousing566 to theholder553. Theside wall576 of thedistal chamber572 has pair of opposing open-endedslots577 that are sized to fit over the T-shapedhandle560 of thestaple driver559 and allow thehandle560 to move axially within theslots577. Theproximal chamber573 has aninternal thread579 that matches anexternal thread579 on the clamp knob570. Acounterbored hole580 through theinternal wall574 connects the proximal573 and distal522 chambers.
• The[0224]cutter567 of thevessel punch mechanism551 is a long slender tubular member which is preferably made of a hardenable alloy of stainless steel. Thedistal end581 of thecutter567 is slightly enlarged with respect to theshaft582 of thecutter567, and there is a counterbore583 within the enlargeddistal end581. The distal edge of thecutter567 has a sharp, beveled cutting edge584. Preferably, at least the cutting edge584 of thetubular cutter567 is hardened. The proximal end of thecutter shaft582 has a snug press fit into thecounter hole580 through theinternal wall574 of thehousing566. Thepunch mechanism551 also includes a clamp569. The clamp569 has along tubular shaft585 which is sized to be slidably received within theinternal lumen586 of thecutter shaft582. Anenlarged head587 on the distal end of theshaft585 is sized to fit within the counterbore583 in the distal end of thecutter567. The distal end of theenlarged head587 has anannular clamping surface588. The proximal end of theclamp shaft585 is inserted into thecutter567 and glued or otherwise fastened to the clamp knob570 which is threaded into theproximal chamber573 of thehousing566. Theanvil568 of thepunch mechanism551 is preferably made of stainless steel. Theanvil568 has an elongated shaft589 that has a sliding fit with theinternal lumen590 of the clamp569. An enlarged head591 on the distal end of the shaft589 is sized to fit within the counterbored distal end583 of the cutter with a very close clearance between the head of the anvil591 and thecutter567. The proximal end of the shaft589 is threaded to attach it to thepunch knob571. Thepunch knob571 has adistal extension592 which is threaded to fit into a threadedhole593 on the proximal end of the clamp knob570.
• When the clamp knob[0225]570 is rotated with respect to thehousing566, the clamp569 is advanced proximally or distally with respect to thecutter567. In its farthest distal position, the clampingsurface588 of the clamp569 is just distal to the cutting edge584 of thetubular cutter567. When thepunch knob571 is rotated with respect to the clamp knob570, theanvil568 is advanced proximally or distally with respect to the clamp569. By moving theanvil568 proximally with respect to the clamp569 when the clamp is in its farthest distal position, the tissue of the target vessel wall can be clamped between the clamp and the anvil. When theclamp knob255 and thepunch knob571 are rotated in unison, theanvil568 and the clamp569 can be withdrawn into thetubular cutter567 to effect the cutting action of thepunch mechanism551. Preferably, the clamp569, theanvil568 and thetubular cutter567 are keyed to one another or otherwise rotationally fixed so that they move axially with respect to one another without relative rotation.
• The[0226]punch mechanism551 as it has just been described, is inserted into thestapling mechanism550 through thelumen249 of thegraft vessel254. The clamp569 of thepunch mechanism551 should be advanced to its farthest distal position before inserting thepunch551 through thegraft vessel254 to avoid damaging the interior wall of thegraft vessel254 with thecutter567 as it passes through. Theset screws575 in thehousing566 of thepunch mechanism551 are screwed into correspondingholes594 in theholder553 of thestapling mechanism550 to secure the two interacting mechanisms together. Thegraft vessel254 occupies an annular space595 between thepunch mechanism551 and the interior surface of thestapling mechanism550. Thus assembled, the anastomosis system, which includes theanastomosis device533 attached to thegraft vessel254 and theapplication instrument536, is prepared to perform an end-to-side anastomosis between thegraft vessel254 and atarget vessel255.
• The operation of the[0227]application instrument536 is illustrated in FIGS.45A-45E. Aslit596 is made in the wall of thetarget vessel255 with a scalpel or other sharp instrument. If it has not been done already, the clamp569 of thepunch mechanism551 is advanced distally by turning the clamp knob570 until theclamp surface588 extends slightly beyond the cutting edge584 of thecutter567, and theanvil568 of thepunch mechanism551 is advanced distally by turning thepunch knob571 until the anvil head591 extends distally from theapplication instrument536. The anvil head591 of thepunch mechanism551 is inserted through theslit596 into thelumen256 of thetarget vessel255, and thedistal edge541 of thefastening flange534 with theeverted end259 of thegraft vessel254 attached is approximated to theexterior surface258 of thetarget vessel255, as shown in FIG. 45A. Thetarget vessel wall255 is then clamped by thepunch mechanism551 by turning thepunch knob571 to move the anvil head591 proximally until thetarget vessel wall255 is firmly gripped between the anvil head591 and theclamp surface588, as shown in FIG. 45B. The clamp feature of thepunch mechanism551 prevents thecutter567 from prematurely cutting through the wall of thetarget vessel255 and it provides a firm support to thetarget vessel wall255 for the stapling step which follows.
• If the anastomosis system is being used to create a proximal anastomosis between a graft vessel and the aorta during a CABG procedure, the clamping feature provides an additional benefit at this point in the procedure. In order to reduce the crossclamp time that the patient is subjected to, many cardiac surgeons prefer to perform the proximal anastomosis while the patient's heart is still beating. This requires isolating a portion of the aortic wall with a nonoccluding side-biting clamp to prevent excessive bleeding from the opening formed in the aorta. This has a number of disadvantages: 1) even a nonoccluding side-biting clamp presents additional resistance to aortic blood flow, possibly reducing cardiac output which may already be low, 2) the side-biting clamp tends to distort the aortic wall, making it harder to create a neat anastomosis, 3) conventional side-biting clamps are difficult to apply in a closed-chest or port-access thoracoscopic CABG procedure, and 4) side-biting clamps may break atherosclerotic tissue loose from the inner wall of the aorta, possibly causing strokes or other complications. The clamping feature reduces the need for the side-biting clamp by clamping directly to the aortic wall around the slit made by the scalpel for inserting the anvil. This creates a fluid-tight seal preventing bleeding through the aortotomy opening, so that the side-biting clamp can be released and removed from the site. It is also possible to avoid the need for the side-biting clamp entirely by quickly inserting the anvil head[0228]591 of thepunch mechanism551 and tightening the clamp569 immediately after creating the aortotomy slit before significant blood loss can occur. If the head of the anvil591 were made with a blade or trocar extending from its distal surface, thedevice536 could pierce and dilate an opening in the aorta wall in the same motion as inserting the anvil591 through the opening, potentially saving time and blood loss.
• In the stapling step, the[0229]staple driver559 is advanced distally by pressing on the T-shapedhandle560, as shown byarrows597 in FIG. 45C. This causes thedistal end563 of thestaple driver559 to press against thecrossbars545 of thestaple members535 and forces theattachment legs544 to exit through theholes539 in thedistal end541 of thefastening flange534. As theattachment legs544 emerge from theholes539, the sharpened distal ends546 of theattachment legs544 pierce thegraft vessel wall259 and the shortstraight section548 traverses thegraft vessel wall259 in a linear path. Optionally, thestaples535 can be advanced through thegraft vessel wall259 before thegraft vessel259 is approximated to thetarget vessel255 so that the surgeon can verify that all of thestaple attachment legs544 have properly pierced the evertedgraft vessel wall259. The sharpened distal ends546 of theattachment legs544 then pierce thetarget vessel wall255. The clamping feature569 of thepunch mechanism551 supports thetarget vessel wall255 and keeps it closely approximated to theeverted end259 of thegraft vessel254 as thestaple members535 penetrate it. As theattachment legs544 penetrate thetarget vessel wall255, thecurved sections547 of theattachment legs544 emerge from the confinement of theholes539 in thefastening flange534 and the elastic memory of the unrestrained curve causes theattachment legs544 to take a curved path outwardly from thecentral orifice537 through thetarget vessel wall255. The distal ends547 of theattachment legs544 resume their J shape, as shown in FIG. 45C, firmly attaching thefastening flange534 and theeverted graft vessel259 to theexterior surface258 of thetarget vessel255.
• Once the[0230]fastening flange534 and thegraft vessel254 are attached, anopening267 is made in thetarget vessel wall255 by turning the clamp knob570 and punchknob571 in unison to withdraw theanvil568 and the clamp569. with thetarget vessel wall255 gripped between them, into thetubular cutter567, as shown in FIG. 45D. This action shears off a small, circular portion of thetarget vessel wall255 to form a fluid communication between thelumen256 of thetarget vessel255 and thelumen249 of thegraft vessel254. To complete the anastomosis, thefastening flange534 is released from theholder553 and thepunch mechanism551 and theentire application instrument536 are withdrawn, as shown in FIG. 45E.
• FIGS.[0231]46A-46D illustrate a second embodiment of the anastomosis system using ananastomosis device600 with aninner fastening flange601, anouter flange602 andstaple members603 made of a superelastic nickel—titanium alloy. The system includes astapling mechanism604 for attaching theanastomosis device600 to the wall of thetarget vessel255 through a previously madeopening267. Theanastomosis device600 has afastening flange605, which is shown in top view in FIG. 46C and in side cross section views in FIGS. 46A and 46B. Thefastening flange605 includes atubular body606 which has aninternal lumen607 of sufficient diameter to accommodate the external diameter of thegraft vessel254. Attached to the distal end of thetubular body606 is aninner flange601 over which thefree end259 of thegraft vessel254 will be everted. On theproximal end610 of thetubular body606 are three radially extendinglugs608, which facilitate grasping theanastomosis device600 while performing the anastomosis. The exterior of thetubular body606 has anexternal step609 so that it is slightly larger in diameter at itsproximal end610 than at itsdistal end611. The interior of thetubular body606 has aninternal step612 so that the internal diameter of the tubular body is slightly smaller at thedistal end610 than at theproximal end611. A plurality ofholes613 pass through thefastening flange605 from theinternal step612 to thedistal surface611 of theinner flange601. Theholes613 are arranged in pairs, six pairs in this illustrative example, to accommodate a like number ofstaple members603.
• An[0232]outer flange602 is concentrically located on thetubular body606. Theouter flange602 is attached to thetubular body606 by a self-lockingring washer614 which has inclinedlugs615 which allow thering washer614 to slide distally with respect to thetubular body606, but which prevent it from sliding proximally. Thering washer614 can be made integrally with theouter flange602 or a separate sheetmetal ring washer614 can be attached to theouter flange602, as illustrated. Theinternal orifice616 of thering washer614 and theouter flange602 is made with threewide slots617 between theinclined lugs615 to allow them to be placed onto thetubular body606 over thelugs615 which extend from theproximal end610 of thetubular body606. Theouter flange602 has adistal surface618 which is slightly concave. Theperipheral edge619 of theouter flange602 has sixnotches620 cut into it which coincide with the location of the distal ends621 of thestaple members603 after they are deployed, as shown in FIG. 46C.
• The[0233]staple members603 are generally an inverted U shape when viewed from the front as in FIG. 46D. Twoattachment legs622 are joined together at their proximal ends by acrossbar623. Viewed from the side as in FIG. 46B, the staple members are somewhat J-shaped with the sharpened distal ends624 curving back in the proximal direction. Thestaple members603 are preferably formed from wire made of a highly resilient biocompatible metal such as a spring-tempered alloy of stainless steel, titanium, or cobalt, or more preferably of a superelastic metal alloy, such as a nickel-titanium alloy.
• For clarity only the distal end of the[0234]stapling mechanism604 has been shown in FIG. 46A. Suitable handle means are provided at the proximal end for actuating thestapling mechanism604. Thestapling mechanism604 has anouter sleeve625, which is a tubular member having three L-shapedfingers626 extending from its distal end that grasp theradially extending lugs615 on the proximal end of thetubular body606 like a bayonet connector. Theclamp sleeve627 is a tubular member which slides telescopically over the exterior of theouter sleeve625. Astaple guide628 resides within theouter sleeve625. Thestaple guide628 is a tubular member having a plurality ofslots629, equal to the number ofstaple members603 in the anastomosis device, extending through the wall from the proximal end to the distal end of theguide628. Theslots629 in theguide628 are sized to fit thestaple members603 therein and to constrain the J-shapedattachment legs622 of thestaple members603 in a straight position prior to deployment, as shown in FIG. 46A. Thestaple guide628 can be made by cutting a plurality ofslots629 through the wall of the tubular member with electrical discharge machining, or thestaple guide628 can be made from two closely fitting concentric tubes by cutting slots like splines in the external surface of the inner tube and sliding the outer tube over it to close the slots. Thestaple driver630 is a tubular member which is slidably received within theouter sleeve625. A plurality offingers631 extend from the distal end of thestaple driver630. Thefingers631 of thestaple driver630 are sized to be slidably received within theslots629 of thestaple guide628.
• The[0235]anastomosis device600 is prepared by inserting thestaple members603 into theslots629 in thestaple guide628 in thestapling mechanism604. Thestaple guide628 holds thestaple members603 in a straightened position within thestapling mechanism604. Thefastening flange605 is inserted into thestapling mechanism604 and theradially extending lugs608 are grasped by the L-shapedfingers626 of theouter sleeve625. The staple holes613 through thetubular body606 are carefully aligned with the distal ends621 of thestaple members603 and thestaple driver630 is advanced slightly to start thestaple members603 into theholes613. Theanastomosis device600 is now prepared to perform an end-to-side anastomosis between agraft vessel254 and the wall of atarget vessel255 as follows.
• To begin, the[0236]graft vessel254 is inserted through thecentral lumen607 of thefastening flange605 and theinternal lumen632 of thestapling mechanism604 by drawing it through with a suture or an elongated grasping instrument. Thedistal end259 of thegraft vessel254 is then everted over theinner flange601 on thedistal end611 of thefastening flange605. Theinner flange601 with theeverted end259 of thegraft vessel254 attached is inserted through anopening267 in thetarget vessel wall255 that has previously been made using an aortic punch or similar instrument. Thestaple driver630 is advanced distally, causing the sharpened ends621 of thestaple members603 to pierce the evertedwall259 of thegraft vessel254 and enter thelumen256 of thetarget vessel256. As thestaple members603 emerge from thedistal end611 of thefastening flange605, theattachment legs622 resume their J-shaped curve and penetrate theinterior surface257 of thetarget vessel wall255, as shown in FIG. 46D. Once thestaple members603 are completely deployed, theclamp sleeve627 is advanced distally with respect to theouter sleeve625, which forces theouter flange602 to move in the distal direction with respect to thetubular body606. As theouter flange602 moves distally, theinner flange601 and thetarget vessel wall255 are pulled into the concavedistal surface618 of theouter flange602 to form a smooth, hemodynamically efficient connection between thelumen256 of thetarget vessel255 and thelumen249 of thegraft vessel254. Thestapling mechanism604 is now removed by rotating theouter sleeve625 to release its grasp on thetubular body606 and withdrawing theentire stapling mechanism604. It should be noted that the embodiment of FIG. 46, like the embodiment of FIG. 43, could optionally be manufactured without aninner flange601, whereby theinner wall257 of thetarget vessel255 is supported by thestaple members603 themselves.
• FIGS.[0237]47A-47B,48A-48B, and49A-49C show an anastomosisstaple device635 which combines a plurality of precurvedinner staple members636 of a highly resilient material with a plurality of deformableouter attachment legs637. FIGS.47A-47B show a top view and a side cross section view of the anastomosis staple in an undeployed state. FIGS.47A-47B show a top view and a side cross section view of the anastomosis staple in a deployed state. FIGS.49A-49C show the sequence of operations for deploying the anastomosis staple device. As shown in FIGS.47A-47C, thedevice635 has a ring-shapedbushing638 with aninternal diameter639 of sufficient size to accommodate the exterior diameter of thegraft vessel254. A plurality ofdeformable attachment legs637, six in this exemplary embodiment, are attached to the proximal end of the ring-shapedbushing638. Thedeformable attachment legs637 are preferably made of a metal which can be plastically deformed and which will maintain its final deformed shape, such as stainless steel or a titanium alloy. Theattachment legs637 can be machined integrally with the ring-shapedbushing638 as shown, or theattachment legs637 can be made separately, for instance by stamping, electrical discharge machining or die cutting a ring ofattachment legs637 from sheet metal, and fastening theattachment legs637 to the ring-shapedbushing638. Theattachment legs637 are typically 0.012 inches thick, 0.040 inches wide and 0.230 inches long. The thickness and width of the attachment legs can vary somewhat depending on the stiffness of the material chosen for theattachment legs637. It may be desirable to radius the edges of theattachment legs637 or to make theattachment legs637 round in cross section in order to reduce the potential for initiating cracks or tears in thetarget vessel wall255. The length of theattachment legs637 can be varied to accommodate different wall thicknesses of thegraft vessels254 andtarget vessels255 to be attached.
• The[0238]attachment legs637 are typically formed flat, then bent or stamped into a curved configuration as shown in FIGS. 47B. Thedistal portion640 of eachattachment leg637 is curved in a circular arc whose center coincides approximately with the point ofattachment641 between theattachment leg637 and the ring-shapedbushing638. Theattachment point641 serves as the bending fulcrum for theattachment legs637 when they are deformed during the anastomosis procedure. Theintermediate portion642 of theattachment legs637 can be left relatively straight, or anintermediate curve642 can be formed in theattachment legs637, as shown in FIG. 47B. The distal ends643 of theattachment legs637 are sharpened so that they will easily penetrate thetarget vessel walls255.
• The ring-shaped[0239]bushing638 has adistal surface644 over which theend259 of thegraft vessel254 will be everted. Thedistal end644 of the ring-shapedbushing638 is flared out slightly to provide a more secure attachment of theeverted end259 of thegraft vessel254 to thebushing638. There are a plurality ofaxial holes645 in the wall of the ring-shapedbushing638 which communicate with thedistal surface644 of thebushing638. Theholes645 are sized to have a close sliding clearance with thelegs646 of theinner staple members636. Preferably, theaxial holes645 are arranged in pairs to accommodate both legs of U-shapedinner staple members636. As shown in FIG. 47A, the currently preferred embodiment has six pairs ofaxial holes645 for six U-shapedinner staple members636. Theaxial holes645 are angled outward slightly, typically by about 10 degrees, from the central axis of the ring-shapedbushing638. Angling theaxial holes645 outward tends to reduce the distance from thedistal surface644 of thebushing638 to the bottom of the curve of thestaple members636 once thestaple members636 have been deployed. There are also a plurality oftransverse holes647 through the wall of the ring-shapedbushing638 to facilitate gripping thebushing638 with thestaple application instrument648.
• The[0240]staple members636 are generally an inverted U shape when viewed from the front as in FIG. 47A. Twostaple legs646 are joined together at their proximal ends by acrossbar649. Viewed from the side as in FIG. 48B, the deployedstaple members636 are somewhat J-shaped with the sharpened distal ends650 curving back approximately 180 degrees in the proximal direction. Thestaple members636 are preferably formed from wire made of a highly resilient biocompatible metal such as a spring-tempered alloy of stainless steel, titanium, or cobalt, or more preferably of a superelastic metal alloy, such as a nickel—titanium alloy. The anastomosisstaple device635 is prepared for use by inserting the curved distal ends651 of the J-shaped staples into theaxial holes645 in the ring-shapedbushing638. The internal walls of theaxial holes645 hold the curved ends651 of thestaple members636 in a straightened position within the ring-shapedbushing638.
• The anastomosis staple of FIGS.[0241]47A-47B and48A-48B is part of a complete anastomosis system which includes a specializedstaple application instrument648 for performing the anastomosis procedure. Thestaple application instrument648 is shown in FIGS.50A-50B. As seen in FIG. 5OB, theinstrument648 has agripper652 which is adapted to hold the ring-shapedbushing638 of the staple device. Thegripper652 is a generally tubular member that has a plurality ofgripping fingers653 extending axially from its distal end. Each of the grippingfingers653 has an inwardly turneddistal tip654 which is sized to fit into one of thetransverse holes647 in the ring-shapedbushing638. The grippingfingers653 are spring-biased outward. A combination gripper actuator and outerattachment leg driver655 is slidably received on the exterior of thegripper shaft656. The actuator/driver655 is generally tubular in shape, having alumen657 with a close sliding fit over the exterior of thegripper652 and a radiused annularstaple driving surface658 on its distal end. When the actuator/driver655 is slid distally over the exterior of the grippingfingers653, the outwardlybiased finders653 are pressed inward so that they grip the ring-shapedbushing638 by engaging the transverse holes647.
• An[0242]inner staple driver659 is slidably received within theinner lumen661 of thetubular shaft656 of thegripper652. Theinner staple driver659 has an annularstaple driving surface660 on its distal end. Theinner staple driver659 has aninternal lumen662 that can accommodate thegraft vessel254 during the anastomosis procedure. Thegripper652, the actuator/driver655 and theinner staple driver659 are held together by a pair of alignment pins663 which are threaded into the wall of the actuator/driver655. Thegripper shaft656 has a pair of opposingaxial slots664 that allow it to slide axially with respect to the actuator/driver655. Theinner staple driver659 has a pair of opposing L-shapedslots665 oriented to allow theinner staple driver659 to slide axially with respect to thegripper652 and the actuator/driver655. Theinner staple driver659 can be moved to a locked position to prevent premature activation of theinner staples636 by withdrawing it distally and rotating it so that the alignment pins663 enter the L-shapedportion666 of theslots665.
• In preparation for the anastomosis procedure, the proximal end of the ring-shaped[0243]bushing638, with the proximal ends of theinner staples636 extending from it, is inserted into thegripper652 with thetransverse holes647 aligned with theends654 of the grippingfingers653. Theinner staple driver659 should be withdrawn to the locked position before thestaple device648 is inserted. The actuator/driver655 is advanced distally, causing theends654 of the grippingfingers653 to flex inward and engage thetransverse holes647 in the ring-shapedbushing638. Theactuator driver655 can be advanced distally until it rests against, but does not deform, theattachment leg637 of thestaple device635.
• At this point the[0244]craft vessel254 is passed through theinternal lumen662 of thestaple applying instrument648 until a short length of thegraft254 extends from the distal end of theinstrument635. Theend259 of thegraft254 is then everted over thedistal surface644 of the ring-shapedbushing638. If desired, a loop of suture can be tied around theeverted end259 of thegraft vessel254 to secure it to thebushing638. Thestaple instrument635, with theeverted end259 of thegraft vessel254 attached, is approximated to theexterior surface258 of thetarget vessel255 where anopening267 in thetarget vessel wall255 has previously been made with a vessel punch or similar instrument. If the anastomosis is part of a port-access CABG procedure, theinstrument635 is inserted into the chest of the patient through an access port made in one of the intercostal spaces.
• The ring-shaped[0245]bushing638 is inserted into theopening267 in thetarget vessel wall255 to approximate the intimal surface on theeverted end259 of thegraft vessel254 with theintimal surface257 of thetarget vessel255, as shown in FIG. 49A. Preferably, theopening267 in the wall of thetarget vessel255 is made slightly smaller than the outer diameter of the ring-shapedbushing638 so that there is some compression around thebushing638 which helps to seal the anastomosis against leakage. Theinner staple driver659 is rotated to release it from the locked position and advanced distally to drive theinner staple members636 through the evertedwall259 of thegraft vessel254. As thestaple members636 exit theaxial holes645 in thebushing638, they resume their J-shapedcurve651 so that they curve back distally and penetrate theinterior surface257 of thetarget vessel wall255, as shown in FIG. 49B. After theinner staple members636 have been deployed, a light tension is exerted on thestaple applying instrument648 to make sure that theinner staple members636 are well seated and the actuator/driver655 is advanced distally to deform theouter attachment legs637. The sharpened distal ends643 of theattachment legs637 penetrate theexterior258 of thetarget vessel wall255 in a circular arc, gathering the tissue and compressing it against the exterior of the ring-shapedbushing638 and the evertededge259 of thegraft vessel254 to form a leak-proof anastomotic seal, as shown in FIG. 49C. The actuator/driver655 is withdrawn in the proximal direction, thereby releasing the ring-shapedbushing638 from thegripper652, and the entirestaple applying instrument648 is withdrawn from the anastomosis site.
• FIG. 51 shows an additional feature which can be used with any of the anastomosis devices described above. This feature is a combination strain relief and compliance[0246]mismatch transition sleeve667. One of the current theories about long-term patency and the causes of restenosis in bypass grafts proposes that the mismatch in vessel compliance between the target vessels, which include the aorta and the coronary arteries, and the graft vessel, typically a saphenous vein, can contribute to the development of intimal hyperplasia, stenosis and occlusion in the graft vessel, especially at the anastomosis where the compliance mismatch is most apparent. Joining a highly compliant vessel, such as a saphenous vein, to a relatively noncompliant vessel, like the aortic wall, places extra strain on the vessels and on the anastomosis. Another cause for mismatched compliance at an anastomosis site is the joining of a compliant blood vessel with a highly noncompliant artificial graft vessel. Additionally, turbulence in the blood flow at the anastomosis site may exacerbate the problem, accelerating the stenosis process. It is preferable that all of the vessels be equally compliant or at least that there is a gradual transition in compliance from one vessel to another. As such, it would be desirable to provide the anastomosis devices with a means to create a gradual transition in compliance between the vessels at the anastomosis site.
• Another concern in anastomosis procedures is to create a gradual curve in the graft vessel leading away from the anastomosis site. This is sometimes necessary because the most convenient angle for attaching the graft vessel to the target vessel does not match the desired path for the graft vessel away from the anastomosis. For instance, in CABG surgery the desired path for the graft vessel is often parallel to the ascending aorta, however the graft vessel must be joined to the ascending aorta at some angle in order to create the anastomosis. Creating a gradual curve leading away from the anastomosis site to avoid kinking or narrowing of the graft vessel lumen is sometimes problematic. This is especially true when the graft vessel is joined at right angles to the ascending aorta. It would be desirable therefore to provide the anastomosis devices with a reliable means to create a gradual curve in the graft vessel leading away from the anastomosis site.[0247]
• The combination strain relief and compliance[0248]mismatch transition sleeve667 is a flexibletubular member668 which can be appended to the proximal end of theanastomosis device669 to support thegraft vessel254 leading away from the anastomosis site. The flexibletubular member668 may have any or all of gradually decreasing stiffness, increasing compliance and increasing diameter as it extends proximally from theanastomosis device669. This will give the graft vessel254 a gradual curve, a gradual change in its radial compliance, and a gradual change in diameter from the constrained diameter within theanastomosis device669 to an unconstrained diameter some distance from thedevice669.
• The[0249]strain relief sleeve667 can be made in any one of several possible constructions, including braided wire or monofilament, a wire or plastic coil, a solid polymer tube or a composite construction, such as a wire coil embedded in a polymer wall. Thestrain relief sleeve667 may also be made of a soft, stretchy, biocompatible polymer, such as polyurethane, silicone, or Gortex (expanded PTFE).
• FIG. 52 shows a[0250]device670 for isolating a portion of thetarget vessel lumen256 to facilitate performing an anastomosis using any of the devices and techniques described herein. Theisolation device670 may be used as an alternative to the side-biting clamp described above for use in the proximal anastomosis procedure during CABG surgery. The side-biting clamp is used in CABG surgery to isolate a portion of the aortic wall so that the proximal anastomosis can be performed while the heart is still beating without excessive bleeding at the anastomosis site. Placing a side-biting clamp thoracoscopically during port-access CABG surgery may prove problematic. A perfusionendoaortic clamp catheter670, as shown in FIG. 52, performs the same functions as the side-biting clamp with a percutaneously placed catheter. Thecatheter670 has a first doughnut-shapedballoon671 and a second doughnut-shapedballoon672 which are interconnected by a large-bore perfusion tube673. Theballoons671672 and theperfusion tube673 are mounted on the distal end of anelongated catheter shaft674. Theballoons671,672 and theperfusion tube673 are preferably made of a semi-elastic polyurethane material so that it can be collapsed for percutaneous entry and so it will resume the appropriate shape when they are deployed. Thecatheter shaft674 may have asingle inflation lumen675 which connects to bothballoons671,672′ or separate inflation lumens connected to each balloon. If desired, thecatheter670 may also be provided with a flushing lumen which connects to a flushing port located on the exterior of theperfusion tube673 between theballoons671,672 for flushing theanastomosis site678 with clear saline to improve visibility.
• In operation, the[0251]balloons671,672 and theperfusion tube673 are introduced percutaneously into a peripheral artery, such as the femoral artery and advance into the ascendingaorta676, preferably under fluoroscopic visualization. When the surgeon is prepared to make the aortotomy incision to start the proximal anastomosis procedure, the first andsecond balloons671,672 are inflated, isolating the portions of theaortic wall677 between the twoballoons671,672 from the blood flow in the aorta. Blood continues to flow through the large-bore perfusion tube673, supplying the rest of the body with blood. With theaortic wall677 isolated, the aortotomy incision can be made at theanastomosis site678 and the anastomosis completed by any of the methods described in the specification. After the anastomosis is complete, theballoons671,672 are deflated and the catheter is withdrawn from theaorta676.
• This catheter approach has certain advantages over the use of a side-biting clamp. First, it isolates a larger portion of the aortic wall so that the surgeon has more choice in the placement of the anastomotic sites. Second, because it isolates a larger portion of the aortic wall it also allows multiple anastomoses to be made to the aorta without having to move the clamp. Third, it does not distort the wall of the aorta as the side-biting clamp does. This may allow more accurate placement of the anastomotic sites and more effective attachment of the anastomosis devices and therefore reduced leakage of the anastomoses.[0252]
• A second, smaller scale version of a[0253]similar catheter device679 is shown in FIG. 53 for isolating a section of acoronary artery682 while performing a distal anastomosis. This device would allow the section of thecoronary artery682 close to the anastomosis to be isolated from the blood flow without blocking blood flow to vital myocardium downstream of the anastomosis site. The availability of rapid and reliable anastomosis devices, such as those described herein, could open the door to performing CABG surgery on patients whose hearts are still beating, with no need at all for cardioplegic arrest. The rapidity of the anastomosis procedure using these devices will minimize the interference from the wall motion of the beating heart that makes hand sutured anastomoses problematic. However, two other obstacles remain: 1) excessive bleeding at the anastomotic site when the coronary artery is incised, and 2) temporary ischemia of the myocardial tissue downstream of the anastomosis site. Thecatheter679 in FIG. 53 solves both of these potential problems. The distal end of the catheter has adistal balloon680 and aproximal balloon681 separated by a few centimeters distance along thecatheter shaft683. Theballoons680,681 may be elastic balloons made of latex, polyurethane or silicone, or they may be inelastic balloons made of polyethylene, polyester or polyamide. Thecatheter shaft683 may have asingle inflation lumen648 which connects to bothballoons680,681 or separate inflation lumens connected to each balloon. If desired, thecatheter679 may also be provided with a flushing lumen which connects to a flushing port located on thecatheter shaft683 between theballoons680,681 for flushing theanastomosis site690 with clear saline to improve visibility. In addition, thecatheter shaft683 has aperfusion lumen685 for blood flow through thecatheter679. Theperfusion lumen685 has one ormore inflow ports686 on thecatheter shaft683 proximal to both of theballoons680,681 and at least oneoutflow port687 at the end of thecatheter679, distal to both of theballoons680,681.
• In operation, the[0254]catheter679 is introduced into thecoronary arterv682 through acoronary guiding catheter688 which is preferably introduced percutaneously from the femoral or brachial artery. Thedistal balloon680 is advanced past thestenosis689 in theartery682, preferably under fluoroscopic visualization, and placed distal to the desiredanastomosis site690. Theproximal balloon681 is placed proximal to the desiredanastomosis site690 at a point which may be proximal or distal to thestenosis689. Theinflow ports686 of theperfusion lumen685, however, should be located proximal to thestenosis689. The proximal681 and distal680 balloons are inflated to isolate the area between them from the blood flow through thecoronary artery682. Blood continues to flow into the artery distal to thecatheter679 through theperfusion lumen685. The distal anastomosis procedure can now be performed on the isolated section of the coronary artery. When the anastomosis is complete, theballoons680,681 are deflated and thecatheter679 is withdrawn.
• A[0255]third catheter device691 is shown in FIG. 54. Thiscatheter device691 is configured to be delivered to the anastomosis site through thelumen249 of thegraft vessel254 which has a number of potential advantages. First, thedevice691 can be used without the need for a femoral or brachial artery puncture or a coronary guiding catheter to deliver thecatheter691 into thecoronary arteries682. Second, thecatheter691 can be deployed under direct or endoscopic visualization by the surgeon without the need for fluoroscopic imaging. Third, the T-shaped configuration of thecatheter691 can help to facilitate approximation of thegraft vessel254 and thetarget vessel255 during the anastomosis procedure.
• The[0256]catheter691 has aproximal catheter body692 connected to a T-shapeddistal portion693. The T-shapeddistal portion693 has twodistal ends694,695, each having aninflatable balloon696,697 at its distal extremity. Theballoons696,697 are each connected to one ormore inflation lumens698 that terminate in a luer fitting at the proximal extremity of theproximal catheter body692. Aperfusion lumen699 connects a separate luer fitting at the proximal extremity of theproximal catheter body692 to the extremities of bothdistal ends694,695 of thecatheter691, distal to theinflatable balloons696,697.
• In operation, the T-shaped[0257]distal end693 of the catheter is passed through thelumen249 of thegraft vessel254 with theballoons696,697 deflated. An incision700 is made in the wall of thecoronary artery682 or other vessel at the desired anastomosis site and bothdistal ends694,695 ofcatheter691 are introduced into thecoronary artery682 through the incision700. Onedistal end695 of thecatheter691 is directed upstream of the anastomosis site and the otherdistal end694 is directed downstream of the anastomosis site. Both of theballoons696,697 are inflated to isolate the portion of thecoronary artery682 between theballoons696,697 from the blood flow in the artery. Two modes of perfusion are possible with thecatheter691. If theupstream end695 of thedistal portion693 of thecatheter691 receives enough blood flow, the blood will pass through theperfusion lumen699 from theupstream side695 to thedownstream side694 to perfuse thecoronary artery682 distal to the anastomosis site700. If the blood flow is insufficient because of a severe stenosis or total occlusion upstream of the anastomosis site700, blood and/or cardioplegic fluid can be injected into thecatheter691 through the luer fitting connected to theperfusion lumen699 at the proximal end of thecatheter691.
• With the anastomosis site[0258]700 isolated from the blood flow, thegraft vessel254 can be approximated to the target vessel with the T-shapedcatheter body693 providing a guide for the approximation. The anastomosis can be performed in a blood-free environment using any one of the devices and methods described above. When the anastomosis is complete, theballoons696,697 can be deflated and the catheter withdrawn through thelumen249 of thegraft vessel254.
• The catheter devices described above are not limited in their use to CABG surgery. Either of the catheter devices could easily be modified to be the appropriate size for use during other bypass operations such as aorto-femoral bypass or femoral-femoral bypass.[0259]
• Port-Access CABG Procedure[0260]
• A vascular anastomosis procedure using the devices and methods of the present invention will now be described in relation to performing a proximal anastomosis on a free graft during a closed-chest or port-access coronary artery bypass graft surgical procedure. Closed-chest or port-access coronary artery bypass graft (CABG) surgery is a newly developed procedure designed to reduce the morbidity of CABG surgery as compared to the standard open-chest CABG procedure. The morbidity is reduced in the port-access CABG procedure by gaining access to the heart and the coronary arteries through one or more access ports which are made in the intercostal spaces of the patient's chest, thereby eliminating the need for a median sternotomy or other gross thoracotomy as is required in open-chest CABG surgery. A port-access coronary artery bypass graft surgical procedure using sutured anastomosis techniques is more fully described in co-pending patent applications, Ser. Nos. 08/023,778 and 08/281,891, which have been incorporated herein by reference.[0261]
• To prepare the patient for the port-access CABG procedure, the patient is placed under general anesthesia and cardiopulmonary bypass (CPB) is established to support the patient's circulatory system during the surgical procedure. Preferably, a femoral-to-femoral CPB system is used to reduce the invasive nature of the procedure. One or[0262]more access ports702 are made through theintercostal spaces703 of the patient's chest by making an incision between theribs705 and placing a trocar with acannula704 through the wall of the chest. The trocar is then withdrawn, leaving thecannula704 as an access port into the chest cavity. Typically, an endoscope, preferably a thoracoscopic surgical microscope, is placed through one of the access ports to allow direct visualization of the heart, the ascending aorta and the coronary arteries.
• Meanwhile a graft vessel is prepared for creating the bypass graft which will redirect blood flow from the ascending aorta to one or more of the coronary arteries downstream of any blockage caused by atherosclerotic disease. Vessels which can be used as free grafts in CABG surgery include veins, such as the saphenous vein, arteries, such as one of the internal mammary arteries or the gastro-epiploic artery, and artificial grafts, such as Dacron or Goretex (expanded PTFE) grafts. If an autologous graft, such as a vein or an artery, is to be used, the vessel is generally harvested from the patient at this time.[0263]
• Depending on the preference of the surgeon, the proximal anastomosis, which joins the graft vessel to the aorta, can be performed before or after the distal anastomosis, which joins the graft vessel to one or more of the coronary arteries. The distal anastomosis is generally performed while the patient's heart is stopped, whereas the proximal anastomosis may be performed with the heart stopped or while the heart is still beating, according to the preferences of the surgeon. To stop the heart, a special endo-aortic clamping catheter, which is described in the aforementioned patent applications, is inserted into the ascending aorta via a percutaneous entry or a surgical cutdown into the femoral artery. An endo-aortic clamping balloon on the distal end of the catheter is inflated in the patient's ascending aorta to block blood flow in the patient's aorta downstream of the coronary arteries. Cardioplegic solution is immediately infused into the patient's coronary arteries through a lumen in the catheter to temporarily stop the patient's heart from beating. Alternatively, the proximal anastomosis can be performed while the heart is still beating by using a side-biting clamp or other device to isolate a portion of the aortic wall from the aortic blood circulation. With a portion of the aortic wall isolated from the systemic circulation by either of these methods, the proximal anastomosis can be performed using any of the devices and methods previously described herein.[0264]
• The rapidity and reliability of performing the anastomoses using the devices and methods of the present invention may, in some instances, allow the entire coronary artery bypass procedure, including the proximal and distal anastomoses to be performed without the need for cardiopulmonary bypass support or cardioplegic arrest of the heart. This would be of even greater benefit to the patient by further decreasing the morbity from the procedure and reducing the likelihood of side effects associated with CPB and cardioplegia. It would also be beneficial to the surgeon and the hospital by reducing the cost and complexity of the CABG procedure.[0265]
• By way of example, the proximal anastomosis procedure will now be described using the two-part anastomosis[0266]staple device100 of FIG. 1. Asmall incision151 is made in the ascendingaorta707 at theanastomosis site706 under endoscopic visualization. Then, thevessel punch mechanism120 and thestapling mechanism119 with theanchor member101 of the anastomosis staple, which have previously been prepared as shown in FIG. 2, are introduced through one of theintercostal access ports702 and positioned at the anastomosis site, as in FIG. 55. Theanchor member101 is attached to the ascendingaorta707 at theanastomosis site706 according to the procedure in FIGS.5A-5D, as follows. Theanvil136 of thevessel punch120 is inserted though theincision151 in theaortic wall707, and theanchor member101 is advanced distally so that theattachment legs105 penetrate theaortic wall707. Then,staple driver127 is advanced to deform theattachment legs105 and fasten theanchor member101 to the exterior wall of theaorta707. Anopening152 is then punched in theaortic Wall707 with thevessel punch120 and thepunch120 is removed along with thetissue153 excised by the punch. Thegraft insertion tool121 and thegraft vessel148, which has previously been prepared with thecoupling member102 as shown in FIG. 6 by everting the distal end of thegraft vessel148 over thecoupling member102, are then inserted though theaccess port702, as shown in FIG. 56, and thegraft vessel148 is attached to the ascendingaorta707 at theanastomosis site706 by inserting thecoupling member102 into theanchor member101 as shown in FIGS.5F-5G.
• The bypass operation is then completed by anastomosing the[0267]distal end708 of the graft vessel to thecoronary artery709 below the stenosis or occlusion, as shown in FIG. 57. The distal anastomosis can be performed using suturing techniques or thegraft vessel148 can be joined to thecoronary artery709 using a second anastomosis staple by following the steps shown in FIGS.5A-5C and FIG. 7C, using the embodiment of thegraft insertion tool122 illustrated in FIGS.7A-7C.
• Alternatively, the proximal and distal anastomoses can be performed in the reverse order, as is preferred by some cardiac surgeons. In this case the distal anastomosis would be performed first, using the[0268]graft insertion tool121 of FIGS.6A-6C, followed by the proximal anastomosis performed using thegraft insertion tool122 of FIGS.7A-7C. When performing the proximal anastomosis as the second anastomosis on a free graft, both ends of the graft vessel can be prepared for anastomosis by attaching acoupling member102 to the proximal and the distal end of thegraft vessel148 and inserting thegraft vessel148 into the chest cavity of the patient through one of theaccess ports702 after attachinganchor members101 to both theaorta707 and thecoronary artery709. Each of thecoupling members102 can then be inserted into itsrespective anchor member101 using theappropriate insertion tool121,122. An alternate technique is to first attach the distal end of thegraft vessel148 to acoronary artery709 using an anastomosis staple or sutures, according to the preference of the surgeon, then, after verifying the correct length of the graft vessel, drawing the proximal end710 of thegraft vessel148 out of the chest cavity through one of theaccess ports702. The free proximal end710 of thegraft vessel148 can be prepared under direct vision by the surgeon by passing the free end of the graft vessel through the lumen of thecoupling member107 and everting it over thedistal end115 of thecoupling member102. Thecoupling member102 with the proximal end710 of the graft vessel attached can be reinserted into the chest cavity through theaccess port702 and inserted into ananchor member101 attached to theaortic wall707 using thegraft insertion tool122 of FIGS.7A-7C. This same technique can be used with the two-piece anastomosis staple for performing a distal anastomosis on a pedicled graft vessel or for performing a distal anastomosis on a free graft after the proximal anastomosis has already been made.
• The operation of the one-piece anastomosis staples of FIGS. 9, 10,[0269]11 or12 can also be understood in relation to FIGS.55-57. Thegraft vessel148 and the one-piece anastomosis staple163 are prepared as described above in relation to FIGS. 13 and 14. Asmall incision151 is made in the ascendingaorta707 with a sharp blade at the intendedanastomosis site706, which has been isolated from the circulation with a side-biting clamp or other isolation device. An elongated punch, which may be similar to thevessel punch120 described in relation to FIGS. 2 and 5D above, is inserted through one of theaccess ports702 in the patient's chest. Anopening152 is made in the wall of the ascendingaorta707 by inserting the anvil of the punch through the incision, then pressing the actuating plunger to advance the tubular cutter over the anvil. The staple applying tool of FIG. 13 with thegraft vessel148 everted over the distaltubular extension166 of theanastomosis staple163, as shown in FIG. 14, is introduced through anaccess port702 and positioned near the punchedhole152 in the ascendingaorta707 as illustrated in FIG. 55. Theflanged end167 of the distaltubular extension166 is passed through thehole152 SO that it is in the position shown in FIG. 10. The wall of the ascendingaorta707 stretches slightly to allow theflange167 to pass through thehole152. Thestaple applying tool179 is pulled back slightly to make sure theflange167 of thestaple163 engages the interior wall of theaorta707, then thelever185 of thestaple applying tool179 is pulled to deform theattachment legs168 of thestaple163 and drive them through theaortic wall707, as shown in FIG. 10. Thelever185 is released and thestaple applying tool179 is rotated to disengage thestaple retainer188 from thetabs170 on the proximaltubular extension169 of thestaple163. Thestaple applying tool179 is withdrawn and the anastomosis is complete.
• As with the two-piece embodiment of the anastomosis staple, the one-piece anastomosis staple of FIG. 9 can also be used for creating the proximal and/or distal anastomoses on a graft vessel in either order, according to the preference of the surgeon. When performing the second anastomosis on a free graft or the distal anastomosis on a pedicled graft, the free end of the graft vessel can be drawn out of the chest cavity through one of the access ports to prepare the end of the graft vessel under direct vision by the surgeon. The graft vessel is prepared by passing the free end of the graft vessel through the lumen of the anastomosis staple and everting it over the distal flange. The anastomosis staple with the free end of the craft vessel attached can be reinserted into the chest cavity through the access port and attached to the wall of the target vessel, which may be the ascending aorta or one of the coronary arteries.[0270]
• Although the foregoing description focuses on the use of the anastomosis system in closed-chest CABG surgery, the system is equally applicable to other situations that require vessel anastomosis, including, but not limited to renal artery bypass grafting, aorto-femoral bypass, femoral-femoral bypass and arterio-venous shunting, such as is commonly used for dialysis. Surgical anastomoses are also performed for various reasons on many different tubular organs of the body other than blood vessels, including the bowel, intestines, stomach and esophagus. While the devices and methods of the present invention are intended primarily for vascular anastomoses, some or all of the embodiments could also be modified for performing end-to-side anastomoses on other tubular organs. Any one of the one or two-piece embodiments of the anastomosis staple device can be supplied preattached to a prosthetic graft vessel. For instance, the two-piece anastomosis staple device could be supplied in a kit, including a natural or artificial graft that is prepared with a coupling member attached to one or both ends and one or two anchor members for attachment to the target vessel(s). Likewise, the one-piece anastomosis staple device can be supplied in a procedural kit preattached to a prosthetic graft vessel. This is equally applicable to artificial graft materials, such PTFE or Dacron grafts, or to natural biological graft materials, including ailografts of human graft vessels, or xenografts such as bovine or porcine graft vessels, either freshly harvested, glutaraldehyde treated or cryogenically preserved. An anastomotic device application instrument, such as those described above, could also be supplied in the procedural kit with one of the anastomotic devices already attached to the distal end of the instrument.[0271]
• While the above is a complete description of the preferred embodiments of the invention, various alternatives, modifications and equivalents may be used. Therefore, the above description should not be taken as limiting the scope of the invention, which is defined by the appended claims.[0272]

Claims (20)

What is claimed is:

1. An anastomosis staple device for connecting a free end of a graft vessel to a wall of a target vessel such that a lumen in the graft vessel is in fluid communication with a lumen in the target vessel through an opening in the wall of the target vessel, the anastomosis staple device comprising:

an anchor member, said anchor member having means for attaching said anchor member to said wall of said target vessel,

a coupling member, said coupling member being configured to attach said free end of said graft vessel to said coupling member, and

a coupling means for attaching said coupling member to said anchor member such that said end of said graft vessel is sealingly connected to said wall of said target vessel and said lumen of said graft vessel is in fluid communication with said lumen of said target vessel through said opening in said wall of said target vessel.

2. An anastomosis fitting for connecting a free end of a graft vessel to a wall of a target vessel such that a lumen in the graft vessel is in fluid communication with a lumen in the target vessel through an opening in the wall of the target vessel, the anastomosis fitting comprising:

an inner flange, said inner flange having a proximal surface and a distal surface and a central orifice of sufficient size to accommodate an external diameter of said graft vessel, said inner flange providing an atraumatic attachment for said end of said graft vessel when said end of said graft vessel is passed through said central orifice and everted over said inner flange, said inner flange being insertable through said opening in said wall of said target vessel,

an outer flange, said outer flange having a proximal surface and a distal surface and a central orifice of sufficient size to accommodate the external diameter of said graft vessel, said distal surface of said outer flange being configured to contact an exterior surface of said wall of said target vessel proximate said opening, and

means for maintaining said outer flange in a selected position with respect to said inner flange such that said everted end of said graft vessel is sealingly connected to said wall of said target vessel and said lumen of said graft vessel is in fluid communication with said lumen of said target vessel through said opening in said wall of said target vessel.

3. The anastomosis fitting ofclaim 2, wherein said inner flange is configured such that the everted end of said graft vessel substantially covers at least said distal surface of said inner flange such that said inner flange is fluidly isolated from said lumen of said target vessel and said lumen of said graft vessel.

4. The anastomosis fitting ofclaim 2, further comprising a tubular body having a proximal end and a distal end, said inner flange being connected to said distal end, said tubular body having a central lumen of sufficient size to accommodate an external diameter of said graft vessel.

5. The anastomosis fitting ofclaim 4 wherein a proximal portion of said tubular body is configured to be slidably received in said central orifice of said outer flange, and said means for naintaining said outer flange in a selected position with respect to said inner flange comprises a locking means for locking said outer flange to said tubular body.

6. The anastomosis fitting ofclaim 5 wherein said locking means comprises a self-locking retaining washer slidably positioned on an exterior surface of said tubular body.

7. The anastomosis fitting ofclaim 3 wherein said outer flange is deformable from an initial configuration wherein said distal surface of said outer flange does not contact said exterior surface of said wall of said target vessel to a deployed configuration wherein said distal surface of said outer flange contacts said exterior surface of said wall of said target vessel.

8. The anastomosis fitting ofclaim 2 wherein said means for maintaining said outer flange in a selected position with respect to said inner flange comprises a deformable means for connecting said outer flange to said inner flange, whereby said deformable means can be deformed to position and hold said outer flange in a selected position with respect to said inner flange.

9. The anastomosis fitting ofclaim 2 wherein said outer flange is divided into a plurality of flange sectors, each of said flange sectors being connected to said inner flange by way of at least one deformable means.

10. The anastomosis fitting ofclaim 9 wherein said deformable means is connected to said inner flange by way of a tubular body, said tubular body having a central lumen of sufficient size to accommodate an external diameter of said graft vessel.

11. The anastomosis fitting ofclaim 2 wherein said outer flange comprises a tubular body connected to said inner flange, said tubular body being deformable from an undeformed configuration to an expanded configuration to form said outer flange.

12. The anastomosis fitting ofclaim 11 wherein said tubular body is divided into a plurality of longitudinal segments, said longitudinal segments being predisposed to expand outward when compressed axially.

13. The anastomosis fitting ofclaim 2, wherein said inner flange has at least two operative positions, including:

a collapsed position wherein said inner flange has a collapsed diameter, and

an expanded position wherein said inner flange has an expanded diameter which is greater than said collapsed diameter.

14. The anastomosis fitting ofclaim 13, wherein said inner flange comprises a plurality to flange sectors, said flange sectors being collapsed toward one another to occupy a diameter equal to said collapsed diameter when said inner flange is in said collapsed position, and said flange sectors being expandable away from one another to occupy a diameter equal to said expanded diameter when said inner flange is in said expanded position.

15. The anastomosis fitting ofclaim 14, further comprising an expansion means for expanding said inner flange from said collapsed position to said expanded position.

16. The anastomosis fitting ofclaim 15, wherein said expansion means comprises a tubular member which, when inserted into said central orifice between said flange sectors, forces said flange sectors from said collapsed position to said expanded position.

17. The anastomosis fitting ofclaim 2, wherein said inner flange comprises a plurality of initially longitudinally oriented segments, said segments being configured to expand radially in response to being compressed axially.

18. The anastomosis fitting ofclaim 17, wherein said initially longitudinally oriented segments have a proximal end which is connected to said outer flange and a distal end, said segments being configured to expand radially when said distal end is compressed axially toward said proximal end.

19. The anastomosis fitting ofclaim 18, wherein said segments have a curved portion intermediate said proximal end and said distal end predisposing said segments to expand radially when said distal end is compressed axially toward said proximal end.

20. A method of performing an anastomosis to connect a free end of a graft vessel to a wall of a target vessel such that a lumen in the graft vessel is in fluid communication with a lumen in the target vessel through an opening in the wall of the target vessel, the method comprising:

attaching said free end of said graft vessel to an inner flange of an anastomotic fitting;

inserting said inner flange with said free end of said graft vessel attached through said opening in said wall of said target vessel and engaging an inner surface of said target vessel with said inner flange;

positioning an outer flange of said anastomostic fitting in contact with an exterior surface of said wall of said target vessel proximate said opening; and

coupling said inner flange and said outer flange such that said graft vessel is sealingly connected to said wall of said target vessel and said lumen of said graft vessel is in fluid communication with said lumen of said target vessel through said opening in said wall of said target vessel.

Images