US20030114867A1 - Surgical clips and methods for tissue approximation - Google Patents

Abstract

Surgical clips, and methods of use thereof, are provided for tissue approximation and attachment, and more particularly, for sealingly joining a graft vessel to a target vessel. The graft vessel has a free end and a graft vessel wall defining a graft lumen. The target vessel has a target vessel wall defining a target lumen and has an opening in the target vessel wall. The anastomosis clip includes a clip body having a distal extremity with a distal end and a proximal extremity with a proximal end. The distal end is configured to penetrate through the graft vessel wall near the free end and through the target vessel wall near the opening such that both the distal and proximal ends of the clip body are outside the graft and target vessels. At least a portion of the clip body is shapable so as to compress the graft vessel wall against the target vessel wall with the target vessel lumen in communication with the graft vessel lumen.

Description

CROSS-REFERENCE TO RELATED APPLICATION
• This application is a continuation of copending application Ser. No. 08/598,513, filed Feb. 8, 1996, which is a continuation-in-part of copending application Ser. No. 08/394,333, filed Feb. 24, 1995, the complete disclosure of which is hereby incorporated herein by reference for all purposes.[0001]
FIELD OF THE INVENTION
• The present invention relates generally to surgical instruments and methods, and more specifically to devices and methods for surgical wound closure, tissue approximation and attachment, and vascular anastomosis, especially coronary artery anastomosis.[0002]
BACKGROUND OF THE INVENTION
• In coronary artery disease, one or more of the coronary arteries which supply oxygenated blood to the heart are partially or entirely blocked by a build-up of atherosclerotic plaque within the artery. This deprives the heart muscle of oxygen and nutrients, leading to myocardial infarction and even death.[0003]
• Coronary artery bypass grafting remains the gold standard for the surgical treatment of severe coronary artery disease. In coronary artery bypass grafting, or CABG, a graft vessel is used to bypass a blockage in a coronary artery by connecting the distal end of the graft vessel to the coronary artery downstream of the blockage and connecting the proximal end of the graft vessel to a source of arterial blood upstream of the blockage. Various types of graft vessels may be used, including a saphenous vein taken from the patient's leg, a radial artery removed from the patient's forearm, or a prosthetic graft made of expanded polytetrafluoroethylene, Dacron, or other suitable material. Additionally, the left or right internal mammary arteries, which originate from the subclavian artery and reside on the top of the chest wall, may be resected at a distal location and left intact proximally, the free distal end then being connected to the diseased coronary artery downstream of the blockage. Similarly, the gastroepiploic artery, which originates from the gastroduodenal artery in the abdomen, may be resected at a distal location in the abdomen and passed into the thorax through a puncture in the diaphragm for attachment to the diseased coronary artery. Other types of graft vessels may also be used, as well as combinations of several different types of graft vessels in order to bypass multiple coronary blockages.[0004]
• The surgical interconnection of two vascular structures, such as a graft vessel and a coronary artery, is a process known as anastomosis. In CABG, the anastomosis of a graft vessel to a coronary artery is particularly challenging. Several factors contribute to this challenge. First, the scale of the vessels is extremely small, the coronary arteries having a diameter on the order of about 1-5 mm, and the graft vessels having a diameter on the order of about 1-4 mm for an arterial graft such as a mammary artery, or about 4-8 mm for a vein graft. In addition, the completed anastomosis must not only provide a sealed connection and a patent blood flow path between the graft vessel and the coronary artery, but must further provide a connection which minimizes the exposure of the blood to foreign material or external vessel surfaces which can cause thrombosis at the anastomosis site. Moreover, recent studies suggests that the anastomosis site should not be dramatically different in compliance relative to either the coronary artery or the vascular graft, since such a “compliance mismatch” may also cause thrombus to form at the anastomosis.[0005]
• Suturing is the technique of choice for coronary anastomosis in the vast majority of CABG cases today. The anastomosis is performed by creating a small opening, or arteriotomy, in the coronary artery, and passing a series of running stitches through the walls of the graft vessel and the coronary artery, respectively, around the perimeter of the arteriotomy so as to compress the end of the graft vessel against the side wall of the coronary artery. The surgeon has a great deal of flexibility in selecting the optimum location for each stitch, based on the shape, structure and condition of the two vessels. The suture needle may be placed initially through the graft vessel wall, and, before the two vessels are closely approximated, the needle then independently placed through the desired location in the target vessel wall. The suture is then tensioned to approximate the two vessels and create a tight, hemostatic seal. The sutured anastomosis thus offers a secure, sealed and patent connection between the two vessels, while having a substantial degree of compliance due to the flexible nature of the suture material.[0006]
• A drawback of the sutured anastomosis is, however, the high degree of skill, dexterity, and acute visualization required. In addition, the completion of the anastomosis takes a significant amount of time, during which the patient is maintained under cardioplegic arrest and cardiopulmonary bypass. The period of cardioplegic arrest should generally be minimized in order to minimize damage to the heart muscle. Further, in recent years, some attempts have been made at reducing the invasiveness and trauma of CABG surgery by working through smaller incisions or “ports” between the ribs and using endoscopic surgical techniques. Performing microvascular anastomoses with conventional sutures is extremely difficulty when working through small ports, particularly if direct vision of the anastomosis site is not possible and reliance upon endoscopic visualization techniques is necessitated.[0007]
• Various ideas have been proposed for simplifying and accelerating the process of coronary anastomosis using sutureless anastomosis devices. For example, in U.S. Pat. No. 4,350,160 to Kolesov et al., a device is disclosed for creating an end-to-end anastomosis by everting each vessel end over a split bushing and driving a plurality of staples through the everted vessel ends. For coronary anastomosis, this device requires that the coronary artery be severed downstream of the blockage and the downstream end dissected away from the surface of the heart in order to allow it to be connected end-to-end to the graft vessel. This adds an undesirable increase in time, difficulty and risk to the procedure. In addition, the staples in the Kolesov device are always positioned in a fixed pattern, allowing no flexibility in selecting the location in which each staple is to be driven through the vessels.[0008]
• In U.S. Pat. No. 4,624,257 to Berggren et al., a device is disclosed for creating either end-to-end or end-to-side anastomoses. The device consists of a pair of rigid rings each having a central opening through which the end of the coronary or graft vessel may be drawn through and everted over the ring. A set of sharp pins extend outwardly from the face of each ring and pierce through the vessel wall to maintain the vessel in the everted configuration. The rings are then joined together to align the end of the graft vessel with the opening in the target vessel. While this device may be suitable for end-to-side anastomosis, eliminating the need to sever and isolate a free end of the coronary artery, the device requires that the side wall of the coronary artery be everted through the central opening of the ring, a maneuver which is likely to be extremely difficult in coronary anastomosis due to the structure and size of the coronary arteries. Moreover, the use of rigid rings that completely encircle the graft vessel and the arteriotomy creates a severe compliance mismatch at the anastomosis site which could lead to thrombosis.[0009]
• An additional device which has been proposed for end-to-side anastomosis is seen in U.S. Pat. No. 5,234,447 to Kaster et al. This device consists of a rigid ring having a plurality of pointed legs extending from the ring axially in the distal direction and a plurality of angled legs extending axially from the ring in the proximal direction. The graft vessel is placed through the middle of the ring and the end is everted over the pointed legs, which puncture the vessel wall and retain it on the ring. The pointed legs are then bent outwardly, and the everted end of the graft vessel and the outwardly-oriented pointed legs are inserted through an arteriotomy in the target vessel so that the pointed legs engage the interior wall of the target vessel. The angled legs on the proximal end of the ring are then bent toward the target vessel to penetrate the outer wall thereof. While the Kaster device has a simple one-piece design and avoids the need to evert the wall of the target vessel over the device as proposed in Berggren, the device maintains a rigid ring structure which results in inadequate compliance at the anastomosis. In addition, the rigidity of Kaster's device leaves the surgeon little flexibility in selecting the optimum location where each leg of the device should be driven into the graft and target vessels, in contrast to the flexibility available when placing suture stitches.[0010]
• U.S. Pat. No. 4,586,503 to Kirsch et al. discloses an alternative scheme for creating microvascular anastomoses. The Kirsch device consists of a plurality of individual clips each consisting of a pair of arcuate legs interconnected by a bridging section. The edges of the vascular tissue to be anastomosed are approximated and everted outwardly so that a clip can be placed over the tissue edges, and the clip is then crimped to permanently deform the legs in an inward position. The clip thereby retains the edges of the tissue together without puncturing the tissue. A plurality of clips are placed around the graft vessel in this manner to accomplish the anastomosis. The Kirsch device eliminates the compliance problems of rigid ring-type devices, and allows the surgeon the flexibility to select the optimum location for the placement of each clip. However, the Kirsch clips suffer from several disadvantages. For example, placement of the clips while maintaining eversion and approximation of the tissue edges is difficult and time-consuming. Typically, two pairs of forceps are needed to hold the tissue edges in approximation while a third hand applies the clip, in contrast to suturing, where only one tissue edge needs to be held at one time while the suture needle is driven through it. The Kirsch clips are especially awkward in endoscopic applications, where access, visualization, and maneuverability of instruments are limited. Moreover, in end-to-side anastomosis, the tissue edges along the arteriotomy must be everted outwardly and approximated with the everted end of the graft vessel, a maneuver which becomes increasingly difficult as the ends of the arteriotomy are approached. In addition, due to variation in vessel size and structure, variation in the crimping force applied, and other factors, the clips may not reliably maintain the anastomotic connection.[0011]
• In view of the foregoing, devices and methods are needed which facilitate the performance of vascular anastomosis, especially coronary anastomosis, but which eliminate the various drawbacks of prior devices. The devices and methods should allow the surgeon to select the specific locations on the graft and target vessels where the device is to be applied, similar to selecting the location of each stitch in a sutured anastomosis. The devices and methods should be relatively simple to utilize without requiring an undue degree of skill and dexterity, even at the small scale of the coronary arteries, and even in endoscopic applications. The devices and methods should be useful for performing end-to-side, end-to-end and side-to-side anastomoses. Further, the devices and methods should produce an anastomosis which is reliably sealed and patent, with a degree of compliance comparable to sutured anastomosis.[0012]
SUMMARY OF THE INVENTION
• The invention provides surgical clips and methods that meet the foregoing needs, and that are useful not only for coronary anastomosis, but for anastomosis of a variety of other vascular structures, as well as in ligation, wound closure and other tissue approximation and attachment applications. The invention offers a simple and convenient solution to coronary anastomosis, allowing the anastomosis to be performed using only two hands more quickly and easily than existing devices, but with the hemostasis, patency, compliance and reliability of sutures. The devices and methods of the invention are useful not only in conventional open surgical procedures, but in endoscopic, laparoscopic, thoracoscopic and other minimally-invasive procedures as well.[0013]
• In a first embodiment of the invention, a surgical clip is provided for approximating or attaching a first tissue layer to a second tissue layer. The first and second tissue layers may be any of various tissue structures, such as flaps of tissue adjacent to a wound or incision in a vessel, organ or body wall, but the invention is particularly suitable for vascular anastomosis, wherein a graft vessel is joined to a target vessel. The graft vessel has a free end and a graft vessel wall defining a graft lumen. The target vessel has a target vessel wall defining a target lumen and has an opening in the target vessel wall, which may be an incision or other opening formed in the target vessel wall (for end-to-side or side-to-side anastomoses), or an opening at a free end of the target vessel (for end-to-end anastomoses). The surgical clip includes a clip body having a distal extremity with a distal end and a proximal extremity with a proximal end. The distal end is configured to penetrate through the graft vessel wall near the free end and through the target vessel wall near the opening such that both the distal and proximal ends of the clip body are outside the graft and target vessels. At least a portion of the clip body is shapable so as to compress the graft vessel wall against the target vessel wall with the target vessel lumen in communication with the graft vessel lumen.[0014]
• By penetrating the graft and target vessel walls, the surgical clip provides the long-term reliability of a sutured connection. In addition, maintaining both ends of the clip outside of both the graft and target vessels minimizes the amount of foreign material contacting blood, eliminates the need for an internal anvil which must be removed after clip application, facilitates visual confirmation of successful application of the clip, and permits manipulation of the ends of the clip to re-apply, reposition or remove the clip. Further, the surgical clip provides a reliable hemostatic seal by having a deformable portion which compresses the graft vessel wall against the target vessel wall. Moreover, through the use of a plurality of individual surgical clips, the invention provides the surgeon with the flexibility to select the ideal location on both the target and graft vessel walls to which each clip should be applied, depending upon vessel structure, condition and shape. The use of multiple independent clips also produces an anastomotic connection having compliance comparable to a sutured anastomosis.[0015]
• The surgical clip may have a variety of configurations. The clip body will generally have an outer surface against which the graft and target vessel walls are compressed. In one embodiment, the proximal extremity comprises a leg extending from the clip body that is movable between an open position spaced apart from the distal extremity and a closed position closer to the distal extremity. The proximal extremity has an inner surface which faces the outer surface of the clip body in the closed position. The clip body is thus “shaped” by moving the proximal extremity into the closed position, thereby compressing the graft and target vessel walls between the inner and outer surfaces. The proximal extremity may be hingedly coupled to the clip body to facilitate movement thereof, but is preferably configured to be inelastically deformed from the open into the closed position.[0016]
• The movable proximal extremity may also be configured to contact or to extend across the distal extremity in the closed position. In one configuration, the proximal extremity has an end portion which includes two generally parallel segments which extend across the distal extremity in the closed position and a slot between the parallel segments for receiving the distal extremity. The proximal extremity may also be configured to shield the distal end of the distal extremity in the closed position to prevent inadvertent injury to tissue. Preferably, the proximal extremity is configured to prevent its passage through the graft and target vessel walls. For example, the proximal extremity may have a cross-sectional area which is substantially larger than that of the distal extremity so that it cannot pass through the puncture created by the distal extremity. The proximal extremity may also be oriented at an angle, usually at least about 90°, relative to the distal extremity to inhibit its passage through the vessel walls.[0017]
• In another embodiment, the distal extremity is movable between an open position spaced apart from the proximal extremity and a closed position closer to the proximal extremity, and the distal extremity has an inner surface which compresses the graft and target vessel walls against the outer surface of the clip body in the closed position. Preferably, the distal extremity is inelastically deformable into the closed position.[0018]
• The distal extremity is preferably oriented such that its inner surface is at an angle of at most about 90° relative to the outer surface of the clip body. The inner surface (or the entire distal extremity) may also be arcuate in shape. The distal extremity is usually tapered to a sharp point at its distal end to facilitate penetration of the graft and target vessel walls. One or more barbs may be provided near the distal end to maintain the graft and target vessel walls on the distal extremity.[0019]
• The invention also provides an applier for applying the surgical clip. The applier includes a holding mechanism for releasably holding a surgical clip and a shaping mechanism for shaping the clip so as to compress the graft vessel wall against the target vessel wall. Although a variety of holding mechanisms are possible, in one embodiment the holding mechanism comprises a pin at the distal end of the applier, in which case the surgical clip includes a middle portion having an aperture for receiving the pin. Various types of shaping mechanisms are also possible, but in an exemplary configuration, the clip applier includes an inner shaft and an outer shaft axially movable with respect to each other. The clip is held by a first of the inner and outer shafts, and the clip body is shaped by engagement with a second of the inner and outer shafts. In a particularly preferred aspect, the clip applier is configured for endoscopic, laparaoscopic, thoracoscopic, or other minimally-invasive procedures, by holding the clip at the end of a small-profile elongated shaft suitable for positioning through a small incision, trocar sleeve, tubular port, cannula or the like. An actuator at the proximal end of the shaft permits remote application of the clip from outside the body cavity.[0020]
• In another embodiment, the surgical clip of the invention comprises a clip body, a needle portion extending from the clip body that has a distal end configured to penetrated the graft and target vessel walls and to extend outside of the graft and target vessels. The clip body is configured to prevent its passage through the graft and target vessel walls so that it remains outside of the graft and target vessels. A retainer is further provided on the clip for retaining the graft and target vessel walls on the needle portion.[0021]
• In one configuration, the retainer comprises a leg attached to the clip body and movable from an open position spaced apart from the needle portion to a closed position closer to the needle portion. The leg may be hingedly movable or inelastically deformable into the closed position. Preferably, the retainer is configured to compress the graft vessel wall against the target vessel wall for reliable hemostasis. The leg may also be configured to shield the distal end of the needle portion in the closed position.[0022]
• Alternatively, the retainer may comprise a barb or other retention device on the needle portion itself. A plurality of barbs may be provided at spaced apart positions along the extremity of the needle portion so that the needle portion may be passed through the graft and target vessel walls a desired amount and the barbs will prevent the needle portion from backing out of the vessel walls. As an alternative to barbs, a retainer which is unidirectionally slidable or threadable onto the needle portion may be provided which is placed on the needle portion after it has been passed through the graft and target vessel walls. The needle portion is preferably hook-shaped, J-shaped or oriented at an angle of at least about 90° relative to the clip body so that the needle portion may be advanced through the vessel walls until its curved portion or the clip body engages the vessel wall. The barbs or other retaining devices are positioned relative to the clip body so as to maintain the graft vessel wall in compression against the target vessel wall.[0023]
• In an additional embodiment, the surgical clips of the invention are configured to be coupled to a flexible ring-shaped band, which is preferably a continuous ring of suture, metal or plastic wire or strip, or other flexible material. The band defines a central opening through which the graft vessel may be received. Each clip has a first portion for engaging the graft vessel wall, and a second portion for engaging the target vessel wall, the first and second portions being configured to retain the graft vessel wall in sealing engagement with the target vessel wall. A plurality of clips are positionable at spaced-apart locations around the band. In this way, application of the clips to the vessels is accomplished by simply placing the band over the end of the graft vessel and applying each clip to the vessel wall. The graft vessel may then be positioned adjacent to the opening in the target vessel and each clip applied to the target vessel wall to create a sealed anastomotic connection. The band may be either left in place, or configured for removal by cutting or other wise detaching the ring from the clips.[0024]
• Preferably, the clips are coupled to the band so as to be slidable to the desired position around the perimeter of the band. In one configuration, the clips have a loop or eyelet through which the band may be slidably received. The clips in this embodiment may have any of various configurations suitable for vascular anastomosis, including those described above, as well as other configurations not specifically described.[0025]
• In a preferred embodiment, a method of joining a graft vessel to a target vessel according to the invention comprises providing a plurality of surgical clips each including a clip body having a distal extremity with a distal end and a proximal extremity with a proximal end; penetrating the graft vessel wall and the target vessel wall with the distal extremity of each surgical clip such that the distal and proximal ends are disposed outside of the graft and target vessels; and shaping a portion of each clip body outside of the graft and target vessels so as to compress the graft vessel wall against the target vessel wall with the graft lumen in communication with the target lumen. In this way, a robust, reliable and hemostatic anastomosis is provided which is simple and convenient to perform using only two hands, which minimizes the amount of foreign material in contact with the blood stream, which allows the surgeon to place each clip in the optimum location based on the size, shape and condition of the vessels, and which provides a degree of compliance in the completed anastomosis comparable to that of sutured anastomoses. The invention thus combines the ease of application, flexibility of position, reliability, and compliance of sutures, with the convenience and quickness of surgical clips.[0026]
• Because of its simplicity and convenience, the invention is particularly well-adapted for use in endoscopic, laparoscopic, thoracoscopic and other minimally-invasive applications. The clips may be applied to a body structure using slender instruments positioned through percutaneous ports such as trocar sleeves, tubular cannulas, or small incisions, under direct visualization through such ports or under video-based visualization by means of an endoscope positioned through a port.[0027]
• The nature and advantages of the invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings.[0028]
BRIEF DESCRIPTION OF THE DRAWINGS
• FIGS.[0029]1A-1B are front elevational views of a surgical clip constructed in accordance with the principles of the invention in an open and a closed position, respectively.
• FIGS. 2A and 2B are front and top cross-sectional views, respectively, of a clip applier for applying the surgical clip of FIGS.[0030]1A-1B in an open position.
• FIG. 2C is a front cross-sectional view of the clip applier of FIG. 2A in a closed position.[0031]
• FIGS.[0032]3A-3B are side cross-sectional views of a distal portion of the clip applier of FIGS.2A-2C in open and closed positions, respectively, illustrating the application of the surgical clip to two portions of tissue.
• FIG. 4 is a perspective view of a distal portion of the clip applier of FIGS.[0033]2A-2C schematically illustrating the use of the surgical clip in the anastomosis of a graft vessel to a target vessel.
• FIGS. 5A and 5C are front elevational views of a second embodiment of a surgical clip constructed in accordance with the principles of the invention in an open and a closed position, respectively.[0034]
• FIG. 5B is a top view of the surgical clip of FIG. 5A in a straightened configuration.[0035]
• FIGS.[0036]6A-6B are side cross-sectional views of a distal portion of a clip applier in open and closed positions, respectively, illustrating the application of the surgical clip of FIGS.5A-5C to two portions of tissue.
• FIGS.[0037]7A-7B are front elevational views of a third embodiment of a surgical clip constructed in accordance with the principles of the invention in an open and a closed position, respectively.
• FIGS.[0038]8A-8B are side cross-sectional views of a distal portion of a clip applier in open and closed positions, respectively, illustrating the application of the surgical clip of FIGS.7A-7B to two portions of tissue.
• FIGS.[0039]9A-9B are front elevational views of a fourth embodiment of a surgical clip constructed in accordance with the principles of the invention in an open and a closed position, respectively.
• FIGS.[0040]10A-10D are side cross-sectional views of a distal portion of a clip applier, in four successive configurations, illustrating the closure of the surgical clip of FIGS.9A-9B.
• FIGS.[0041]11A-11B are perspective views of two embodiments of an anastomosis clip system constructed in accordance with the principles of the invention.
• FIGS.[0042]12A-12F are front views of various embodiments of anastomosis clips useful in the anastomosis clip system of FIGS.11A-11B.
• FIG. 12G is a front view of the anastomosis clip of FIG. 12F in a closed position.[0043]
• FIGS.[0044]13A-13C are perspective views of the anastomosis clip system of FIG. 11A schematically illustrating the use of the anastomosis clip system for the anastomosis of a graft vessel to a target vessel.
• FIGS. 14A and 14C are front views of a further embodiment of a surgical clip according to the invention in an open and a closed position, respectively.[0045]
• FIG. 14B is a top view of the surgical clip of FIG. 14A in a straightened configuration.[0046]
• FIG. 15A is a side cross-sectional view of a clip applier for applying the surgical clip of FIGS.[0047]14A-14C.
• FIGS.[0048]15B-15C are side cross-sectional and top views, respectively, of a distal portion of the clip applier of FIG. 15A.
DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS
• A first embodiment of a surgical clip according to the invention is illustrated in FIGS.[0049]1A-1B.Surgical clip20 comprises aclip body22, adistal extremity24 attached to a first end ofclip body22 and aproximal extremity26 attached to a second end ofclip body22.Distal extremity24 has a sharpdistal point28 configured to penetrate one or more layers of tissue such as a wall of a vessel, and is sufficiently rigid to allow the distal extremity to be driven through such tissue without bending or buckling.Distal extremity24 may be straight, angled, or arcuate, and may include barbs or other means of retention, as further described below. The distal extremity will have a length sufficient to pass through the combined thickness of all tissue layers to be fastened together usingclip20, preferably about twice the combined thickness of the tissue layers, e.g. about 2-5 mm for coronary anastomosis applications, or larger for application to thicker tissues such as the aorta, heart wall, intestines, bowel, or fascia
• [0050]Proximal extremity26 is movable between an open position in which it is spaced-apart fromdistal extremity24 as shown in FIG. 1A, and a closed position in which it is closer todistal extremity24, as shown in FIG. 1B.Proximal extremity26 may be movably attached -to clipbody22 in various ways, including by a pivot pin, living hinge or the like, but, in a preferred embodiment, is attached by adeformable leg30, usually constructed of an inelastically deformable metal so that once it is placed in the closed position,proximal extremity26 will not return to the open position without similar deformation. If a hinge arrangement is used, a latch (not shown) may be provided onclip body22 to engage and maintain the proximal extremity in the closed position.Proximal extremity26 has aninner surface32 which faces anouter surface34 ofclip body22 in the closed position. In the open position,inner surface32 is disposed sufficiently apart fromouter surface34 to facilitate placement ofdistal extremity24 through the tissue layers without interference, usually being at an angle of at least about 45°, usually about 60°-120°, and preferably about 90°, relative toouter surface34. In the open position, clip20 thus forms a general C-shape or U-shape, with a gap between the distal and proximal extremities. The size of the gap will depend upon the size and nature of the tissue to whichclip20 is to be applied, with the distance betweendistal extremity24 andproximal extremity26 usually ranging from about 0.5-8.0 mm, more particularly about 1.0-5.0 mm, and preferably, in coronary applications, about 1.5-3.0 mm.
• In the closed position,[0051]inner surface32 is preferably separated fromouter surface34 by a distance of less than about the combined thickness of the tissue layers to be fastened together withclip20. In this way, the tissue layers will be compressed against one another betweenproximal extremity26 andclip body22, providing important advantages, as described in more detail below. The amount of tissue compression will depend upon the nature of the tissue, the need for a fluid seal, the internal pressures of any fluid within the tissue, and other factors, but will usually compress the tissue layers so as to reduce their combined thickness by at least about 10%, and preferably about 30%-50% from their combined, uncompressed thickness. In an exemplary embodiment suitable for coronary anastomosis,inner surface32 is separated fromouter surface34 by a distance of no more than about 0.02-1.0 mm, and preferably 0.05-0.3 mm, at the closest point between the two surfaces which contact the tissue layers. In other applications involving thicker tissues this distance will be greater, as needed to apply suitable compressive force to the tissues without unnecessarily cutting, crushing or otherwise damaging the tissues.
• [0052]Proximal extremity26 is preferably configured to shielddistal point28 ofdistal extremity24 in the closed position to avoid the possibility of the distal point causing inadvertent injury to tissue. In one configuration,proximal extremity26 has anouter side36 which has a length generally equal to that ofdistal extremity24 so that theupper end38 ofouter side36 is aligned withdistal point28 in the closed position.Outer side36 further has a shape selected to match that ofdistal extremity24, having an arc generally matching that of the inner side ofdistal extremity24 in the embodiment of FIG. 1. In other configurations,proximal extremity26 may include a slot, channel or aperture alongouter side36 which receives all or a portiondistal extremity24 in the closed position, or a separate sleeve or cap (not illustrated) may be placed overdistal point28.
• [0053]Clip body22 includes a means by whichclip20 may be held by a clip applier or other instrument for applying the clip to body tissue. In the embodiment of FIGS.1A-1B, the clip holding means comprises anaperture40 which extends through the clip body in a direction generally parallel to the axis of movement ofproximal extremity26.Aperture40 may have various shapes and may, instead of a single aperture, include two or more separate apertures, depending upon the type of clip applier to be used.
• FIGS.[0054]2A-2C illustrate aclip applier42 suitable for applyingsurgical clip20 of FIGS.1A-1B.Clip applier42 has anouter shaft44 having adistal end46, aproximal end48, and alumen50. Aninner shaft52 is slidably disposed withinlumen50.Inner shaft52 has aclip holding mechanism54 at its distal end which includes two transverse pins56 (better seen in FIGS.3A-3B) that are received withinaperture40 ofclip20.Clip20 is held so thatdistal extremity24 andproximal extremity26 extend generally radially outward from the longitudinal axis ofinner shaft52. As shown in the top view of FIG. 2B, aclip cover55 is slidably mounted withinouter shaft44 parallel to a distal portion ofinner shaft52. Aspring57 disposed aroundinner shaft52 withinlumen50 engages a proximal end ofclip cover55 and biases it in a distal direction. In this way, clip cover55 may be retracted in the proximal direction to place aclip20 onpins56 as in FIG. 2A, then returned to the distal position of FIG. 2B so as to retainclip20 onpins56 as the clip is applied.Clip cover55 has a cut-out58 at its distal end to exposedistal extremity24 ofclip20 to facilitate penetrating tissue with the distal extremity.
• An actuator handle[0055]60 includes a pair ofleaves62 having proximal ends64 pivotally attached to the proximal end ofinner shaft52 so that actuator handle60 remains a fixed distance fromsurgical clip20 whether open or closed. Alink66 is pinned at one end to eachleaf62 and at its other end to acollar67 attached to theproximal end48 ofouter shaft44. In this way, pivoting leaves62 inwardly translatesouter shaft44 distally relative toinner shaft52 from the open position of FIG. 2A to the closed position of FIG. 2C, thereby closingsurgical clip20. A leaf spring (not shown) engages the inner sides of eachleaf62 to bias the leaves outward into the position of FIG. 2A. Alternatively, a tension or compression spring may be mounted aroundinner shaft52 so as to engage the proximal end ofouter shaft44 and bias it proximally.
• While[0056]clip applier42 is illustrated in a single-fire design capable of holding only one clip at a time, those of ordinary skill in the art will understand that the clip applier of the invention may be designed to hold multiple clips which can be applied repeatedly without manually reloading a clip into the applier after each application. For example, pins56 could be configured to allow multiple clips to be stacked in parallel, withouter shaft44 being designed to engage and close only the outer-most clip in the stack. Alternatively, clips20 could be lined up serially in an axial channel withinouter shaft44 and a pusher could exert a distal force against the proximal end of the line. The pusher would feedclips20 one-by-one ontopins56 or other suitable clip holding means after each clip is closed.
• [0057]Clip applier42 preferably is configured for use in thoracoscopic, laparoscopic, or other endoscopic surgical procedures, whereinclip holding mechanism54 and a distal portion ofouter shaft44 andinner shaft52 are positioned through a trocar sleeve, cannula, port or small incision in the body wall, preferably between the ribs if operating in the thoracic cavity. The distal portion of the clip applier must therefore have a small profile so as to fit through a small access passage, and a sufficient length to reach the surgical site within the body cavity. In an exemplary embodiment, the outer diameter ofouter shaft44 and the largest transverse dimension ofclip holding mechanism54 are less than about 12 mm, preferably less than about 10 mm, andouter shaft44 has a length of at least about 10 cm, preferably at least about 20 cm.
• FIGS.[0058]3A-3B illustrate a distal portion ofclip applier42 in the open and closed positions, respectively. Two layers G, T of tissue to be fastened together are penetrated withdistal point28 ofclip20 so that the edges of the tissue are disposed within the gap betweendistal extremity24 andproximal extremity24. Actuator handle60 ofclip applier42 is then actuated by pivotingleaves62 inwardly, translatingouter shaft44 distally relative toinner shaft52.Distal end46 of the outer shaft engages the proximal side ofproximal extremity26 and deforms it into the closed position of FIG. 3B. The edges of tissue layers G, T are thereby compressed betweenproximal extremity26 andclip body22.Leaves62 contact each other and/orouter shaft44 in the closed position, preventing translation ofouter shaft44 beyond that necessary to closeclip20 with the desired degree of compression to avoid excessive crushing of tissue layers G,T. This compression of tissue is particularly advantageous when usingclip20 to perform anastomosis of two vessels such as arteries. Such compression not only accelerates the growing together of the two vessels, but creates an immediately hemostatic seal at the anastomosis site.
• The performance of vascular anastomosis using[0059]clip applier42 andclip20 is illustrated in FIG. 4, which shows a graft vessel G being anastomosed to a target vessel T. Graft vessel G may be any of a variety of vascular structures, including blood vessels, intestines, bowel and other body ducts. The invention is particularly useful, however, for anastomosis of small blood vessel such as the coronary arteries and the conduits commonly used in coronary artery bypass grafting (CABG), including internal mammary arteries, saphenous vein grafts, radial artery grafts, gastroepiploic arteries, and other natural and artificial vascular grafts. The invention may be used either for “proximal” anastomosis—that is, the connection of the upstream end of a graft to a source of blood such as the aorta—or “distal” anastomosis, the connection of the downstream end of the graft to a coronary artery below a blockage in the artery. Thus, in the context of coronary anastomosis, the term “graft vessel” is used herein to mean the vascular graft used to provide a new conduit to a coronary artery, while “target vessel” is used to mean either the arterial blood source vessel (e.g. aorta) or the coronary artery to which the “graft vessel” is connected. In other applications, “graft vessel” and “target vessel” may simply refer to the two vessels, organs or other structures which are being connected together. In addition, while FIG. 4 illustrates an end-to-side anastomosis as is common in CABG surgery, the clips and appliers of the invention are useful in forming end-to-end and side-to-side anastomoses as well.
• As shown in FIG. 4, an end GE of graft vessel G is connected to a side wall TW of target vessel T around an opening O formed in wall TW by a surgical knife, scissors or other suitable instrument. In an artery such as a coronary artery, opening O is known as an arteriotomy. Initially, either inside or outside the body cavity, one or[0060]more clips20 may be attached to graft vessel end GE by puncturingdistal point28 through the graft vessel wall from the exterior side toward the interior side. Usually, this will be done withclip20 held at the distal end ofclip applier42, which is then positioned adjacent to the opening O in target vesselT. Distal point28 is then penetrated through target vessel wall TW from the interior of the vessel outward such that the distal edge of graft vessel end GE is approximated with the edge of opening O. This may require slight pursing up of target vessel walls TW around the opening and/or slight flaring or eversion of graft vessel end GE, which is accomplished using surgical forceps or other suitable instruments.Distal extremity24 is passed through the graft and target vessel walls untilclip body22 is contacting the wall of graft vessel G. Actuator handle60 ofclip applier42 is then actuated so thatouter shaft44 is advanced distally, deformingproximal extremity26 into the closed position ofclip20′.Clip applier42 is then removed by withdrawingpins56 fromaperture40. A plurality ofclips20, usually at least about4, preferably6-30, depending upon vessel size, the need for a fluid seal, the internal pressures in the vessels, and other factors, are applied around the perimeter of opening O in this way until a sealed and secure anastomosis has been achieved.
• It may be seen that the graft and target vessel walls are compressed between[0061]proximal extremity26′ andclip body22′, providing a secure and hemostatic connection.Distal point28′ is safely shielded byproximal extremity26′ to prevent interference or injury to surrounding tissue. Eventually, graft vessel G and target vessel T will grow together at the anastomosis. However, clips20, being made of a biocompatible material such as stainless steel, titanium or titanium alloy, tantalum, elgiloy, MP35N, or cobalt chromium-nickel alloy, may be left in the body indefinitely to ensure that the anastomosis remains intact.
• An additional embodiment of a surgical clip according to the invention is illustrated in FIGS.[0062]5A-5C.Surgical clip70 includes aclip body72, adistal extremity74 and aproximal extremity76.Distal extremity74 has a sharpdistal point78 adapted to penetrate tissue.Clip body72 has anaperture80 for receivingpins56 onclip applier42.Proximal extremity76 has anend portion82 adapted to overlap or cross-overdistal extremity74 in the closed position shown in FIG. 5C. As illustrated in FIG. 5B, showing a top view ofclip70 in a flattened configuration,end portion82 has a bifurcated construction with a pair ofparallel segments84 separated by aspace86.Segments84 are separated by a distance of at least the transverse width (or diameter, if round) ofdistal extremity72 to allowdistal extremity74 to be received withinspace86 in the closed position of FIG. 5C.Proximal extremity76 is movable between the open position of FIG. 5A and the closed position of FIG. 5C, preferably being constructed of a biocompatible metal or other deformable material so that the proximal extremity may be inelastically deformed into the closed position. Alternatively,proximal extremity76 may be hingedly coupled to clipbody72 andend portion82 may be provided with a catch (not shown) which engagesdistal extremity74 in the closed position.Clip70 may also be constructed of a thermally responsive shape memory alloy such as Nitinol (Raychem Corp.), whereby, oncedistal extremity74 has been applied to the target tissue, heat may be applied to clip70 using heated forceps or other heat-tipped probe (or by heating the distal end of the clip applier itself) so as to raise the proximal extremity to a transition temperature in which it resumes the closed position of FIG. 5C.
• In order to facilitate closure of[0063]clip70 in a repeatable and predictable hinge-like manner, anotch87 may be provided on the inner surface ofproximal extremity76 at the junction of the proximal extremity andclip body72. When a distally directed force is applied to endportion82 using clip applier42 (described below),proximal extremity76 tends to buckle atnotch87, allowing the proximal extremity to rotate about an axis passing generally through the notch without excessive deformation of the proximal extremity.
• [0064]Clip70, as withclip20 above, is constructed so as to compress the tissue layers to which the clip is applied betweenproximal extremity76 andclip body72.Proximal extremity76 has aninner surface88 which faces anouter surface90 ofclip body72 in the closed position. The clip is preferably configured so that, in the closed position of FIG. 5C,inner surface88 is separated fromouter surface90 adjacent todistal extremity74 by a distance of less than the combined thickness of all the tissue layers to which the clip is being applied, preferably about 0.05-0.3 mm for coronary distal anastomosis.
• The closure of[0065]clip70 by means of aclip applier92 is illustrated in FIGS.6A-6B.Clip applier92 may be constructed similarly to clipapplier42 of FIGS.2-3, having anouter shaft94 with alumen96 extending through it, and aninner shaft98 withinlumen94 over whichouter shaft94 is axially slidable. The proximal portion of the clip applier, not shown in FIGS.6A-6B, may be constructed like that ofclip applier42, with an actuator handle configured to translateouter shaft94 distally when actuated. Aclip holding mechanism100 is mounted to the distal end ofinner shaft98, and includes a pair oftransverse pins102 configured to extend throughaperture80 inclip70.Clip70 is thus held in an orientation in whichdistal extremity74 is disposed transverse to, preferably about orthogonal to, the longitudinal axis ofinner shaft98. A movable clip cover (not shown) like clip cover55 of FIGS.2-3 may also be provided at the distal end ofinner shaft98 to retainclip70 onpins102.Proximal extremity76 is disposed so that the curved outer surface of itsend portion82 is engaged by the distal end ofouter shaft94 when the outer shaft is advanced distally. The distal end ofouter shaft94 may be shaped so as to smoothly and completely deformproximal extremity76 into the closed position of FIG. 6B, including, for example, an annular undercut104.
• In use, a[0066]clip70 is placed onpins102 and the clip cover is allowed to slide distally overclip body72 to retain it on the applier.Distal point78 onclip70 is penetrated through the tissue layers T, G to which the clip is to be applied as shown in FIG. 6A. The actuator handle is then actuated, advancingouter shaft94 distally overinner shaft98 to engageend portion82 ofclip70 and deform it into the closed position shown in FIG. 6B. The bifurcated end ofend portion82 crosses overdistal extremity78, completely enclosing tissue layers T, G. Advantageously, tissue layers T, G. are compressed betweenend portion82 andclip body72, creating a secure and fluid-tight connection.
• FIGS.[0067]7A-7B illustrate an additional embodiment of a surgical clip according to the invention.Clip110 includes aclip body112, adistal extremity114 and aproximal extremity116. As in previous embodiments,distal extension114 has a sharpdistal point118 configured to penetrate tissue.Proximal extremity116 has anaperture120 which facilitates holding the clip in a clip applier as described below.Proximal extremity116 is movable relative to clipbody112 between an open position spaced apart fromdistal extremity114 and a closed position closer todistal extremity114, shown in FIG. 7B. Preferably, the proximal extremity is made of a deformable metal which may be inelastically deformed into the closed position.Proximal extremity116 has aninner surface122 which faces anouter surface124 ofclip body112 in the closed position. Adjacent to the base ofdistal extremity114,inner surface122 is preferably spaced apart fromouter surface124 in the closed position by no more than the combined thickness of all tissue layers to which the clip is to be applied so as to compress the tissue therebetween.Proximal extremity116 also has anouter side126 which is configured to shielddistal point118, preferably having a shape and dimension substantially the same as that ofdistal extremity114 so thatouter side126 lies adjacent and parallel to a substantial portion ofdistal extremity114 in the closed position.Clip body112 has aproximal side127 which facilitates closure of the clip, as described below.
• The use of[0068]clip110 with aclip applier128 is illustrated in FIGS.8A-8B.Clip applier128 may have a construction like that ofclip applier42 of FIGS.2-3, having anouter shaft130 with alumen132 extending through it, and aninner shaft134 disposed withinlumen132 over whichouter shaft130 is slidable. An actuator handle (not shown) like that shown in FIGS.2A-2C is provided at the proximal end ofinner shaft134 and is coupled toouter shaft130 such that actuation of the handle translatesouter shaft130 distally. Aclip holding mechanism136 is fixed to the distal end ofinner shaft134 and includes a recessedarea138 configured to receiveproximal extremity116 ofclip110, and atransverse pin140 configured to extend throughaperture120. Ashelf142 along an inner edge of recessedarea138 prevents rotation ofclip110 aboutpin140. In this way,clip110 is held withdistal extremity114 extending generally in the radial direction from the longitudinal axis ofinner shaft134. Aclip cover144 is slidably mounted withinlumen132 parallel to a distal portion ofinner shaft134 and is movable from a proximal position shown in FIGS.8A-8B to a distal position in which the clip cover extends overproximal extremity116 ofclip110 to retain it onpin140. Aspring146 withinlumen132 engages the proximal end ofclip cover144 and biases it into the distal position.
• When the actuator handle of[0069]clip applier128 is actuated,outer shaft130 is advanced distally so that its distal end engagesproximal side127 ofclip110, thereby deforming the clip into the closed position shown in FIG. 8B.Distal extremity114 is driven in a generally rotational manner about an axis located roughly at the junction betweenproximal extremity116 andclip body112.Recess138 is configured to allowdistal extremity114 to be moved completely into the closed position without interference withinner shaft134. After closure,clip cover144 may be retracted away from holdingmechanism136 andclip110 then released frompin140.
• Still another embodiment of a surgical clip according to the invention is illustrated in FIGS.[0070]9A-9B.Surgical clip150 includes aproximal extremity152 and adistal extremity154.Distal extremity154 has a sharpdistal point160 for penetrating tissue.Proximal extremity152 includes anaperture162 to facilitate holdingclip150 in a clip applier, as described below.Distal extremity154 is movable between the open position of FIG. 9A and the closed position of FIG. 9B. Anotch155 is disposed at the junction of the distal and proximal extremities which causesdistal extremity154 to pivot in a hinge-like manner about an axis passing generally through the base of the notch when a transverse force is applied todistal extremity154.Clip150 is preferably made of a deformable metal so as to remain in the closed position when closure force is released.Distal extremity154 has aninner surface156 which faces anouter surface158 ofproximal extremity152. In the closed position, at a point adjacent to the junction of the distal and proximal extremities,inner surface156 is preferably separated fromouter surface158 by less than the combined thickness of the tissue layers to whichclip150 is to be applied, so as to compress the tissue between the distal and proximal extremities. It is most preferred thatnotch155 be configured to allow the edges of the tissue to reside within the notch, such that when the clip is closed, the layers of tissue will be compressed within the notch itself.
• A distal portion of an[0071]applier164 for closingclip150 is illustrated in FIGS.10A-10D.Applier164 includes anouter shaft166 having alumen168, and aninner shaft170 over whichouter shaft166 is slidable. An actuator handle like that described above in connection with FIGS.2A-2C is attached to the proximal end ofinner shaft170 and coupled toouter shaft166 such that actuation of the handle movesouter shaft166 proximally relative toinner shaft170. Thus, for this embodiment, links66 of FIGS.2A-2C will be oriented such that the outer ends pinned toleaves66 are distal to the inner ends pinned toouter shaft166, thereby pulling the outer shaft proximally when the leaves are pivoted inwardly. In this embodiment,outer shaft166 is rotatably mounted tocollar67 so as to be rotatable relative toinner shaft170 for reasons which will become apparent below.
• A[0072]clip holding mechanism172 is attached to the distal end ofinner shaft170 and includes a pair oftransverse pins174 over which clip150 may be placed. Aclip cover176 is slidably mounted in parallel to a distal portion ofinner shaft170 and is biased distally by aspring178 disposed withinlumen168 which engages the proximal end of the clip cover. In this way, after a clip is placed onpins174 withclip cover176 in the retracted position shown,clip cover176 is allowed to return to a distal position coveringproximal extremity152 of the clip so as to retain it on pins174.
• An[0073]anvil180 extends distally from a distal end ofouter shaft166 and has atransverse end182 generally orthogonal to a longitudinal axis of the outer shaft (and generally parallel to the axis of movement of distal extremity154). In order to facilitate penetratingdistal extremity154 through the tissue to which the clip is to be applied,anvil180 is initially positioned proximally ofdistal extremity154 as shown in FIG. 10A by maintaining leaves. Alternatively,anvil180 itself may be mounted toouter shaft166 so as to be pivotable or rotatable to a position suitably distant fromdistal extremity154.Anvil180 is positioned so thattransverse end182 may be positioned distally of and generally perpendicular to distal extremity of154 of the clip, as illustrated in FIGS.10A-10B. In this way, when the actuator handle ofapplier164 is actuated,transverse end182 is drawn in the proximal direction, engagingdistal extremity154 and deforming it into the closed position shown in FIG. 10C.
• A surgical clip system according to the invention is illustrated in FIGS.[0074]11A-11B.Clip system190 includes plurality ofclips192 coupled to aflexible band194.Clips192 include, as shown in FIG. 12A, aproximal extremity195, aneedle portion196 having a sharp distal point198 for penetrating tissue, and acoupling200 for attachment to band194.Needle portion196 is preferably curved or J-shaped with its distal end being at an angle of no more than about 90, and preferably about 45-85 relative toproximal extremity195. Preferably,coupling200 comprises a loop, eyelet, or other structure through whichband194 may be inserted that allowsclip192 to slide alongband194. Alternatively,coupling200 may be configured to non-movably attachclip192 to the band, such as by clamping or crimping onto the band, by bonding or welding the coupling to the band, or by allowing the band to be knotted or looped through the coupling.Needle portion196 preferably includes abarb202 which prevents the needle portion from being removed from the tissue to which it is applied.
• [0075]Band194 is a flexible biocompatible material such as suture or an elastomeric or metallic strap, band or cable.Band194 is preferably a continuous annular ring, but may also be a non-continuous or broken ring biased into a generally annular shape, with a retainer on each end to retainclips192 on the band. Usually the shape ofband194 will be circular, but could alternatively be a variety of other non-circular shapes including elliptical, egg-shaped, cobra head-shaped, oval, or the like. In any case, the flexibility of the band allows it to conform to whatever shape is desirable for the particular vascular structures with which it is being used.Clips192 may be mounted to band194 with the allneedle portions196 pointing outward as shown, or with some ofneedle portions196 pointing inward. As shown in FIG. 11B,clips192 may also be attached to band194 so that some extend upward from the band, while others extend downward from the band.
• FIGS.[0076]12B-12G illustrate various alternative embodiments of clips for use inclip system190. In FIG. 12B, a length ofhypotube204 is mounted over proximal extremity195B. Ahole206 is disposed near the proximal end ofhypotube204 through whichband194 may be inserted. Thedistal end208 ofhypotube204 engages the tissue through which needle portion196B is inserted and prevents its movement upward along proximal extremity195B. Preferably, the length ofhypotube204 is selected so that the distance betweendistal end208 and barb202B is less than the combined thickness of the tissue layers through which needle portion196B is inserted so that the tissue is compressed between the hypotube and the barb.
• In FIG. 12C, clip[0077]192C has a plurality ofbarbs210 arranged sequentially along needle portion196C. Astop212 is disposed on proximal extremity195C. In this way, the layers of tissue to which clip192C is applied may be translated along needle portion196C until the outer layer contacts stop212.Barbs210 prevent the tissue from moving away fromstop212. Preferably, the distance betweenstop212 andbarbs210 is less than the combined thickness of the tissue to allow the tissue to be compressed between the stop and the barbs.
• In FIG. 12D, clip[0078]192D has a configuration likeclip192 of FIG. 12A, but in this embodiment the clip is constructed of a shape memory alloy such as Nitinol (Raychem Corp.). At body temperature the clip has a closed shape in which distal point198D is close to or contacting proximal extremity195D so as to define an enclosed space in which the tissue is retained. The clip may be isothermally transformed from an open to a closed shape by using needle drivers or other suitable instruments to hold distal point198D away from proximal extremity195D then release the distal point after it has been applied to tissue. Preferably, however, the clip is thermally transformed by heating the clip to the material's transition temperature using a heated probe or needle driver until the clip assumes the closed shape.
• In FIG. 12E, clip[0079]192E has ahypotube214 mounted to proximal extremity195E as in FIG. 12B, and includes aretainer216 mounted to proximal extremity195E which abuts the distal end ofhypotube214. Adistal retainer218 is threadably or slidably received over needle portion196E which may be placed on the needle portion after it has been applied to the tissue. The tissue may be advanced along needle portion196E until it engagesretainer216, anddistal retainer218 then moved into contact with the opposing side of the tissue to compress it between the two retainers.
• In FIGS.[0080]12F-G, clip192F has a pair of opposing needle portions220A,220B connected by abridging segment222.Bridging segment222 may include aloop224 which enhances deflection of needle portions220. Clip192F is movable from the open configuration of FIG. 12F to the closed configuration of FIG. 12G wherein needle portion220A,220B cross over one another to define an enclosed space in which the tissue may be retained. Preferably, clip192F is made of a superelastic shape memory alloy such as Nitinol. In one embodiment, the clip is biased into the closed configuration at ambient and body temperature, and is isothermally held open using appropriate instruments to apply needle portions220 to the target tissue, then released to allow the clip to close. In an alternative embodiment, the material has a transition temperature above ambient temperature at which it resumes the closed shape from the open shape. In this way, after clip192F has been applied to tissue in the open configuration, heat may be applied to the clip using a heating probe or heated forceps to cause it to assume the closed configuration.
• It should be understood that the embodiments illustrated in FIGS.[0081]12A-12G are only exemplary of the wide variety of clips that may be used in the surgical clip system of the invention. Moreover, any of the clips illustrated in FIGS.1-10 above may be used inclip system190 of FIGS.11A-11B by, for example, providing an additional aperture in the clip body through whichband194 may extend.
• FIGS.[0082]13A-13C illustrate the use ofclip system190 in the anastomosis of a graft vessel G to a target vessel T. Initially,band194 to which clips192 are coupled is placed over the end GE of graft vessel G. Vessel end GE is then everted overclips192 to allow eachneedle portion196 to penetrate the graft vessel wall from the exterior surface of the vessel toward the interior surface (which now faces outwardly) as shown in FIG. 13B.Clips192 may be repositioned alongband194 as needed to allow selection of the optimum location at which eachneedle portion196 penetrates the graft vessel wall based on the shape and condition of the vessel. An opening O is formed in the target vessel wall corresponding to the size and shape of everted graft vessel end GE using a surgical knife or scissors. Everted graft vessel end GE is then inserted into opening O and the edges of vessel end GE are approximated with the edges of opening O. Eachneedle portion196 is then grasped with surgical needle drivers or forceps and penetrated through the wall of target vessel T from the interior toward the exterior thereof. The autonomy of eachclip192, the flexibility ofband194 and the compliance of graft vessel G allow eachclip192 to be manipulated and positioned to penetrate the target vessel wall at the optimum location according to the shape and condition of the vessel.Needle portions196 are inserted through the target vessel wall untilbarbs202 pass through to the exterior of the vessel. The vessel walls are thus compressed betweenbarbs202 andproximal extremities195, providing a secure and hemostatic connection. Optionally,band194 may then be severed and removed fromclip couplings200. This ensures that each clip is completely autonomous and unrestricted by the other clips, providing a compliant anastomosis comparable to a sutured anastomosis.
• An additional embodiment of a surgical clip according to the invention is illustrated in FIGS.[0083]14A-14C. In this embodiment,surgical clip230 may be formed by cutting out a two-dimensional pattern from a flat piece of material as shown in FIG. 14B, making the clip more simple and economical to manufacture.Clip230 has adistal extremity232, aproximal extremity234, and a flangedcentral portion236 therebetween which has a transverse width substantially wider than the distal extremity.Distal extremity232 has adistal point233 configured to penetrate tissue.Proximal extremity234 is bifurcated into two spaced-apartsegments238 defining anopening240 therebetween in whichdistal extremity232 may be received in the closed position of FIG. 14C.Distal extremity232 is disposed at an angle of about 30°-120°, preferably about 60°-120°, relative to flangedcentral portion236.Proximal extremity234 is preferably at an angle of at least about 90° relative to flangedcentral portion236 to facilitate closure of the clip in the manner described below.
• Flanged[0084]central portion236 is configured to be held by anapplier242, illustrated in FIGS.15A-15C.Applier242 is preferably adapted for holding a plurality ofclips230 simultaneously and automatically feeding and applying the clips in succession.Applier242 has aninner shaft244 having adistal end246, aproximal end248 and alumen250 therebetween. Anactuator252 is mounted to theproximal end248, and has a pair ofpivotable leaves254 extending distally and outwardly therefrom. Anouter shaft256 is slidably disposed overinner shaft244 and has adistal end258 and aproximal end260. A pair oflinks262 are pinned at their outer ends toleaves254 and at their inner ends to acollar263 attached toproximal end260 ofouter tube256. In this way, when the user pivots leaves254 inwardly,outer shaft256 is translated distally relative toinner shaft244. A flat spring (not shown) may be mounted toleaves254 to bias them in the outward position, or a tension spring (not shown) may be mounted toouter shaft256 to bias it in the proximal direction.
• [0085]Inner shaft244 has anaxial channel266 along one side ofinner lumen250 configured to slidably receive a plurality ofclips230. As illustrated in FIG. 15B,channel266 has a width wide enough to receive flangedcentral portions236 ofclips230. Awall268 separates channel266 fromlumen250 and has aslot270 narrower than flangedcentral portions236, but wide enough to allowdistal extremities232 andproximal extremities234 to slide axially. In this way, a plurality ofclips230 may be lined up end to end inchannel266, with the distal extremity of each clip abutting the proximal extremity of an adjacent clip. Apusher272 is mounted to the proximal end ofinner shaft244 and is biased distally byspring274.Pusher272 has adistal end276 configured to push against the most proximal clip inchannel266, thereby urging all ofclips230 towarddistal end246.
• [0086]Channel266 is angled laterally as it approachesdistal end246, and terminates at anabutment278 against which the distalmost clip230′ is positioned. This exposes most ofdistal extremity232′ to facilitate applying it to one or more layers of tissue, and positionsproximal extremity234′ adjacent todistal end258 ofouter shaft256. In this way, whenactuator252 is actuated,outer shaft256 engagesproximal extremity234′ ofclip230′ and urges it into the closed position of FIG. 14C. As shown in FIG. 15C,slot270 widens at the distal end ofchannel266 to a width wider than flangedcentral portion236′, allowingclip230′ to be withdrawn fromchannel266 after it has been closed. Whenclip230′ has been withdrawn, the next clip in line is urged distally bypusher272 until it contacts abutment278, where it is ready for application. Thus, a plurality of clips may be applied successively to a surgical site within a body cavity without removing the applier from the body cavity to reload clips.
• [0087]Clip applier242 may be preloaded with a plurality ofclips230 and disposed of upon application of all of the clips. Alternatively,inner shaft244 may be detachable fromactuator252, allowing the actuator and outer shaft to be sterilizable and reusable, withinner shaft244 being replaced or reloaded with clips between uses. In addition,clip applier242 is preferably configured for endoscopic uses, having a length and profile suitable for positioning through a trocar sleeve or other small percutaneous access port into a body cavity.
• While the above is a complete description of the preferred embodiments of the invention, various alternatives, substitutions, modifications, and equivalents of the embodiments described are possible without departing from the principles thereof. Therefore, nothing disclosed above should be taken to limit the scope of the invention, which is defined by the appended claims.[0088]

Claims (57)

What is claimed is:

1. A surgical clip for sealingly joining a graft vessel to a target vessel, the graft vessel having a graft vessel wall defining a graft lumen, the target vessel having a target vessel wall defining a target lumen, the surgical clip comprising:

a clip body;

a needle portion extending from the clip body and having a distal end configured to penetrate the graft and target vessel walls and extend outside of the graft and target vessels, the clip body being configured to prevent passage of the clip body through the graft and target vessel walls; and

a retainer disposed outside of the graft and target vessels for retaining the graft and target vessel walls on the needle portion.

2. The surgical clip ofclaim 1 wherein the retainer comprises a leg attached to the clip body movable between an open position spaced apart from the needle portion and a closed position closer to the needle portion for retaining the graft and target vessel walls thereon.

3. The surgical clip ofclaim 2 wherein the retainer is configured to compress the graft vessel wall against the target vessel wall.

4. The surgical clip ofclaim 3 wherein the retainer has an inner surface and the clip body has an outer surface which faces the inner surface in the closed position, the retainer being configured to compress the graft and target vessel walls between the inner and outer surfaces.

5. The surgical clip ofclaim 4 wherein the needle portion is disposed at a an angle of no more than about 120° relative to the outer surface of the clip body in the open position.

6. The surgical clip ofclaim 2 wherein an end portion of the retainer is configured to extend across the needle portion in the closed position.

7. The surgical clip ofclaim 6 wherein the retainer has two generally parallel segments for extending across the needle portion on opposing sides thereof and a slot between the parallel segments for receiving the needle portion.

8. The surgical clip ofclaim 1 wherein the retainer comprises at least one barb on the needle portion.

9. The surgical clip ofclaim 1 wherein the needle portion is hook-shaped.

10. The surgical clip ofclaim 2 wherein the retainer shields the distal end of the needle portion in the closed position.

11. The surgical clip ofclaim 2 wherein the retainer contacts the needle portion in the closed position.

12. The surgical clip ofclaim 1 wherein the clip body includes a middle portion configured to be held by a clip applier for applying the clip.

13. The surgical clip ofclaim 2 wherein the middle portion has a substantially larger cross-sectional area than the needle portion.

14. The surgical clip ofclaim 12 wherein the middle portion has an aperture therein for receiving a portion of the clip applier.

15. The surgical clip ofclaim 1 wherein the clip body includes a coupling for attachment to a flexible band.

16. The surgical clip ofclaim 1 wherein the needle portion has a length of at least about twice the combined thickness of the graft and target vessel walls.

17. An anastomosis device for sealingly joining a graft vessel to a target vessel, the graft vessel having a free end and a graft vessel wall defining a graft lumen, the target vessel having a target vessel wall with an opening therein and defining a target lumen, the anastomosis device comprising:

a flexible ring-shaped band defining a central opening in which the graft vessel may be received; and

a plurality of clips coupled to the band and positionable at spaced apart locations around the band, each clip having a first portion for engaging the graft vessel wall and a second portion for engaging the target vessel wall, the first and second portions being configured to retain the graft vessel wall in sealing engagement with the target vessel wall.

18. The anastomosis device ofclaim 17 wherein the clip has a distal extremity for penetrating the graft and target vessel walls.

19. The anastomosis device ofclaim 18 wherein the clip is generally hook-shaped, the distal extremity being oriented at an angle of at least about 90° relative to a proximal portion of the clip.

20. The anastomosis device ofclaim 17 wherein the clip has a loop for slidably receiving the band.

21. The anastomosis device ofclaim 18 wherein at least a portion of the clip is movable between an open and a closed position so as to retain the graft and target vessel walls on the distal extremity.

22. The anastomosis device ofclaim 21 wherein the movable portion of the clip is configured to remain outside of the graft and target vessels when the distal extremity has penetrated the graft and target vessel walls.

23. The anastomosis device ofclaim 22 wherein the distal extremity has a distal end, the distal end being configured to be disposed outside the graft and target vessels when the distal extremity has penetrated the graft and target vessel walls.

24. The anastomosis device ofclaim 21 wherein the movable portion of the clip is deformable from the open position to the closed position.

25. The anastomosis device ofclaim 21 wherein the movable portion is spaced apart from the distal extremity in the open position and is closer to the distal extremity in the closed position.

26. The anastomosis device ofclaim 21 wherein the distal extremity is movable between the open and closed positions.

27. The anastomosis device ofclaim 18 further comprising a retainer for retaining the graft and target vessel walls on the distal extremity.

28. The anastomosis device ofclaim 27 wherein the retainer comprises at least one barb on the distal extremity.

29. An anastomosis system for sealingly joining a graft vessel to a target vessel, the graft vessel having a free end and a graft vessel wall defining a graft lumen, the target vessel having a target vessel wall with an opening therein and defining a target lumen, the anastomosis system comprising:

at least one anastomosis clip including a clip body having a distal extremity with a distal end and a proximal extremity with a proximal end, the distal end being configured to penetrate through the graft and target vessel walls; and

a clip applier including a holding mechanism for releasably holding the anastomosis clip such that the distal end may be passed through the graft vessel wall near the free end and through the target vessel wall near the opening such that both the distal and proximal ends of the clip body are outside the graft and target vessels, and a shaping mechanism disposed outside the graft and target vessels for shaping at least a portion of the clip body so as to compress the graft wall against the target vessel wall with the target vessel lumen in communication with the graft vessel lumen.

30. The anastomosis system ofclaim 29 wherein the proximal extremity comprises a leg extending from the clip body movable between an open position spaced apart from the distal extremity and a closed position closer to the distal extremity.

31. The anastomosis system ofclaim 30 wherein the proximal extremity shields the distal end of the distal extremity in the closed position.

32. The anastomosis system ofclaim 29 wherein the distal extremity is movable from an open position spaced apart from the proximal extremity and a closed position closer to the proximal extremity.

33. The anastomosis system ofclaim 32 wherein the distal extremity has an inner surface and the clip body has an outer surface which faces the inner surface in the closed position, the distal extremity being configured to compress the graft and target vessel walls between the inner and outer surfaces in the closed position.

34. The anastomosis system ofclaim 33 wherein the inner surface of the distal extremity is disposed at a an angle of no more than about 120° relative to the outer surface of the clip body in the open position.

35. The anastomosis system ofclaim 29 wherein the clip body includes a middle portion configured to be held by the clip applier.

36. The anastomosis system ofclaim 35 wherein the middle portion has a substantially larger cross-sectional area than the distal extremity.

37. The anastomosis system ofclaim 36 wherein the clip applier has a pin on a distal end thereof and wherein the middle portion of the clip body has an aperture therein for receiving the pin.

38. The anastomosis system ofclaim 35 wherein the holding mechanism is configured to hold the middle portion in a stationary position relative to the clip applier as the shaping mechanism shapes the clip body.

39. The anastomosis system ofclaim 29 wherein the clip applier is configured to hold a plurality of clips.

40. The anastomosis system ofclaim 39 wherein the clip applier has an axial channel and the clip has a middle portion having a width wider than the distal extremity, the middle portion being configured to be axially slidable along the axial channel.

41. The anastomosis clip ofclaim 29 wherein the clip applier has an inner shaft and an outer shaft movable with respect to each other, the clip body being held by a first of either the inner or the outer shaft and the clip body being shaped by a second of either the inner or the outer shaft.

42. A method of sealingly joining a graft vessel to a target vessel, the graft vessel having a free end and a graft vessel wall defining a graft lumen, the target vessel having a target vessel wall defining a target lumen and having an opening therein, the method comprising:

providing a plurality of anastomosis clips each including a clip body having a distal extremity with a distal end and a proximal extremity with a proximal end;

penetrating the graft vessel wall and the target vessel wall with the distal extremity of each anastomosis clip such that the distal and proximal ends are disposed outside of the graft and target vessels; and

shaping a portion of each clip body outside of the graft and target vessels so as to compress the graft vessel wall against the target vessel wall with the graft lumen in communication with the target lumen.

43. The method ofclaim 42 wherein the shaping step comprises moving the proximal extremity of the clip body from an open position spaced apart from the distal extremity to a closed position closer to the distal extremity.

44. The method ofclaim 42 wherein the shaping step comprises moving the distal extremity of the clip body from an open position spaced apart from the distal extremity to a closed position closer to the distal extremity.

45. The method ofclaim 42 wherein the shaping step comprises generally inelastically deforming a portion of the clip body.

46. The method ofclaim 42 wherein the shaping step comprises compressing the graft and target vessel walls between an inner surface of the distal extremity and an outer surface of the proximal extremity.

47. The method ofclaim 42 further comprising shielding the distal end of the distal extremity outside the graft and target vessels after penetrating the graft and target vessel walls.

48. The method ofclaim 42 wherein the target vessel comprises a coronary artery on the heart.

49. The method ofclaim 48 wherein the graft vessel comprises a vessel selected from the group including mammary arteries, vein grafts, arterial grafts, and artificial grafts.

50. The method ofclaim 42 wherein the step of penetrating comprises, after penetrating the graft vessel wall, selecting a position for penetrating the target vessel wall, and positioning the distal extremity relative to the target vessel wall so as to penetrate the target vessel wall at said position.

51. The method ofclaim 42 wherein the step of penetrating is performed without continually maintaining the graft vessel wall in contact with the target vessel wall.

52. The method ofclaim 51 further comprising positioning the graft vessel wall relative to the target vessel wall after penetrating the graft vessel wall but before penetrating the target vessel wall.

53. The method ofclaim 52 wherein the target vessel is in a body cavity, the step of penetrating comprising penetrating the graft vessel wall outside the body cavity, positioning the graft vessel in the body cavity, and penetrating the target vessel wall in the body cavity.

54. The method ofclaim 52 wherein the target vessel is in a body cavity, the step of shaping being performed with an elongated instrument positioned in the body cavity through a percutaneous penetration.

55. The method ofclaim 54 wherein the elongated instrument is positioned through a tubular cannula into the body cavity.

56. The method ofclaim 54 wherein the elongated instrument comprises a clip applier.

57. The method ofclaim 56 further comprising repeating the steps of penetrating and shaping for a plurality of anastomosis clips without removing the clip applier from the body cavity.

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