US20040225306A1 - Paired expandable anastomosis devices - Google Patents

Abstract

A paired, expandable anastomosis device joins two vessels together and can expand and contract with changes in the size of the two vessels. The anastomosis device has two expandable rings with a plurality of holding tabs. The holding tabs of one ring are shaped to enable a graft vessel tissue to be everted through one of the rings and to be held on one of the rings. Similarly, the holding tabs of the other ring are shaped to enable a target vessel to be everted through the other ring and to be retained by the holding tabs. Once the graft and target vessels are loaded, the rings are adapted to be brought together to a position in which the graft and target vessels are anastomosed together.

Description

RELATED APPLICATIONS
• The present application is a continuation of U.S. patent application Ser. No. 10/035,084 titled Paired Expandable Anastomosis Devices, which was filed on Dec. 27, 2001 on behalf of Duane D. Blatter, Michael C. Barrus and Troy J. Orr, which is a continuation-in-part of U.S. patent application Ser No. 09/737,200 titled Compression Plate Anastomosis Apparatus and Related Systems, which was filed on Dec. 14, 2000 on behalf of Duane D. Blatter, Kenneth C. Goodrich, Michael C. Barrus, and Bruce M. Burnett, which is a continuation-in-part of U.S. patent application Ser No. 09/460,740, which issued as U.S. Pat. No. 6,569,173 on May 27, 2003, titled Compression Plate Anastomosis Device, which was filed on Dec. 14, 1999 on behalf of Duane D. Blatter, Kenneth C. Goodrich, Mike Barrus, and Bruce M. Burnett. application Ser. Nos. 10/035,084, 09/737,200, and 09/460,740 are each incorporated herein by reference.[0001]
TECHNICAL FIELD
• The present invention is directed generally to an anastomosis device. More particularly, the present invention is directed a paired, expandable device that joins one vessel to another.[0002]
BACKGROUND OF THE INVENTION
• An anastomosis is an operative union of two hollow or tubular structures. Anastomotic structures can be part of a variety of systems, such as the vascular system, the digestive system or the genitourinary system. For example, blood is shunted from an artery to a vein in an arteriovenous anastomosis, and from the right pulmonary artery to the superior vena cava in a cavopulmonary anastomosis. In other examples, afferent and efferent loops of jejunum are joined in a Braun's anastomosis after gastroenteroscopy; the ureter and the Fallopian tube are joined in a ureterotubal anastomosis, and the ureter and a segment of the sigmoid colon are joined in a ureterosigmoid anastomosis. In microvascular anastomosis, very small blood vessels are anastomosed usually under surgical microscope.[0003]
• An anastomosis is termed end-to-end when the terminal portions of tubular structures are anastomosed, and it is termed end-to-side when the terminal portion of a tubular structure is anastomosed to a lateral portion of another tubular or hollow structure. In an end-to-side anastomosis, we often refer to the structure whose end is anastomosed as the “graft vessel” while the structure whose side wall is anastomosed is referred to as the “receiving structure” or “target vessel”.[0004]
• The operative union of two hollow or tubular structures requires that the anastomosis be tight with respect to the flow of matter through such structures and also that the anastomosed structures remain patent for allowing an uninterrupted flow of matter therethrough. For example, anastomosed blood vessels should not leak at the anastomosis site, the anastomotic devices should not significantly disrupt the flow of blood, and the anastomosis itself should not cause a biological reaction that could lead to an obstruction of the anastomosed blood vessels. In particular, anastomosed blood vessels should remain patent and they should ideally not develop hyperplasia, thrombosis, spasms or arteriosclerosis.[0005]
• Because anastomosed structures are composed of tissues that are susceptible to damage, the anastomosis should furthermore not be significantly detrimental to the integrity of these tissues. For example, injury to endothelial tissue and exposure of subintimal connective tissue should be minimized or even eliminated in vascular anastomosis.[0006]
• Because structures to be anastomosed are internal, an anastomosis requires a degree of invasion. The invasive character of an anastomosis, however, should be minimized subject to the reliable performance of a satisfactory anastomosis. Accordingly, there has been a noticeable trend during the last quarter of this century towards less invasive surgical intervention, a surgical style that is termed minimally invasive surgery. This style is characterized by pursuing a maximal treatment effect with minimal damage to surrounding and overlying normal structures. In addition, successful minimally invasive procedures should procure patency and they should minimize damage to the tissues of the anastomosed structures themselves.[0007]
• Particularly in the field of vascular anastomosis, it is acknowledged that there is an increasing demand for an easier, quicker, less damaging, but reliable procedure to create vascular anastomosis. This demand is further revitalized by the movement of vascular procedures towards minimally invasive procedures. See Paul M. N. Werker and Moshe Kon, Review of Facilitated Approaches to Vascular Anastomosis Surgery, Annals of Thoracic Surgery, Vol. 63 (1997) pp. S122-S127.[0008]
• Anastomosis techniques generally intend to provide leak-proof joints that are not susceptible to mechanical failure, and they also intend to minimize damage and reduce the undesirable effects of certain operational features that may lead to post-anastomosis complications. Damage to be minimized and operational features whose undesirable effects should be reduced include endothelial coverage injury, exposure of subintimal connective tissue, exposure of an intraluminal foreign component, blood flow interruption, irregularities at the junction, adventitial tissue stripping, intimal injury, installment of a foreign rigid body, use of materials that may have toxic effects, damage to surrounding tissue, extensive vessel eversion, and tissue plane malalignment. A common feature of most conventional stapling, coupling and clipping techniques, particularly when applied to small-diameter vessels, is that they require a temporary interruption of the blood stream in the recipient vessel. As the instrumentation that is needed at the anastomosis site becomes complex and cumbersome, a wider open area is needed for accessing the anastomosis site, thus leading to an increasingly invasive procedure.[0009]
• Post-anastomosis complications include neointimal hyperplasia, atherosclerosis, thrombosis, stenosis, tissue necrosis, vascular wall thinning, and aneurism formation. In particular, potential for thrombosis and for other complications is increased when the anastomosis site does not expand and contract with systole and diastole, causing flow disturbances as blood crosses the anastomosis. Therefore, a flexible and expandable anastomosis device that responds to changing blood pressure during systole and diastole is needed to decrease the potential for thrombosis and other complication.[0010]
• Potential for flow disturbance at the anastomosis site is also increased when the opening at the anastomosis site has a relatively small diameter. Of course, it is desirable to minimize the size of instruments utilized to form the anastomosis. Smaller instruments minimize the intrusiveness of the procedure. What is needed, therefore, is an anastomosis device that expands upon release and stretches the tissue at the anastomosis opening, enabling the anastomosis to have a larger diameter than the initial anastomosis opening.[0011]
• Also needed is an anastomosis device that acts external to vessels without penetrating at least one of the vessels and that creates an anastomosis more quickly than conventional techniques, with minimal interruption of blood flow.[0012]
SUMMARY OF THE INVENTION
• It is an object of the present invention to provide a device for joining vessels together that minimizes complications such as thrombosis through the use of expandable rings that expand and contract with changes in fluid flow through the vessel after anastomosis is complete.[0013]
• It is a further object of the present invention to provide an anastomosis device that avoids restriction of the lumen at the anastomosis by radially expanding upon deployment, thus minimizing complications such as thrombosis.[0014]
• Additionally, another object of the invention is to provide an anastomosis device that joins vessels together through the use of expandable rings that are guided to each other by guides.[0015]
• A further objection of this invention is to provide devices for joining vessels together in a secure manner such that the portions defining the openings of the vessels are not penetrated.[0016]
• A further object of this invention to provide an anastomosis device that efficiently and reliably joins two vessels together at an anastomosis site.[0017]
• The present invention is a paired, expandable anastomosis device that joins one vessel opening to another vessel opening. The anastomosis device has two rings. Referred to herein as first and second rings. In one embodiment each ring is made of connected flexible segments. Each flexible segment has two arms that are hingedly connected to form expandable V-shaped segments.[0018]
• One embodiment of the anastomosis device has a ring is designed so that a portion of a target vessel can be everted through and held on the ring during the anastomosis procedure. The other ring of this embodiment is designed so that a portion of a graft vessel can be everted through and held on the ring during the anastomosis procedure.[0019]
• Each ring has a holding surface, such as a plurality of holding tabs, to hold the everted vessel tissue. Holding tabs are preferably configured with rounded tips to avoid penetrating the vessel walls. The holding tabs of the ring used to anchor the graft vessel on the ring may have barbs or hooks to more securely hold the graft vessel.[0020]
• The holding tabs in each ring are preferably oriented relative to the holding tabs of the opposing ring so that when the rings are brought together, each one of the holding tabs in a rings is opposite the space between two neighboring holding tabs in the opposing ring. When the rings are brought together so that the tips of the holding tabs enter or at least close to entering the opposing spaces between the holding tabs of the other ring, the everted tissue will be held together, creating a secure anastomosis.[0021]
• Once the target and graft vessels are loaded onto the anastomosis device, the rings are guided together. Several embodiments are discussed that enable the rings to be guided together. In one embodiment, the anastomosis device includes a plurality of guides which guide the movement of one ring to the other ring. The rings may have a plurality of guides adapted to receive guideposts. The guides are preferably sized to frictionally engage the guideposts.[0022]
• The rings have a loading position in which the vessels can be loaded onto the rings. In one embodiment, the guideposts of the second ring are completely inserted into the guides when in the loading position. The guideposts of the first ring are partially inserted into the guides so that the rings maintain an offset configuration. In this loading position, the holding tabs of the first ring are sufficiently spaced from the holding tabs of the second ring so that the graft vessel can be everted onto one ring and the target vessel can be everted onto the other ring. After the rings are loaded, they are brought together to create a secure anastomosis. The rings may be brought together manually or by the use of a device specifically designed for use with the rings, such as an attachment actuaction device. Once the rings are brought together, the frictional engagement of the guides and guideposts prevents the rings from inadvertently sliding on the guides.[0023]
• The anastomosis device of the present invention provides an efficient, reliable anastomosis. Because the rings are expandable, the inventive anastomosis device minimizes complications caused with anastomosis devices of the prior art. Once the expandable rings are deployed to the anastomosis position, the rings permit the vessel tissue defining the anastomosis to expand and contract with expansion and contraction of the vessels. Additionally, the expandable rings radially expand to a deployed position when released from an external operator or tongs so that the vessel tissues defining the vessel openings are stretched to a diameter greater than the diameter of the initial opening in the target vessel. Also, no foreign material is placed in the interior of the vessel because the vessel tissue is everted onto the rings and the anastomosis is formed by bringing the everted interior of the graft vessel into contact with the everted, interior portion of the target vessel.[0024]
BRIEF DESCRIPTION OF THE DRAWINGS
• In order that the manner in which the above-recited and other advantages and objects of the invention are obtained, a more particular description of the invention briefly described above will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments of the invention and are not therefore to be considered to be limiting of its scope, the invention will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:[0025]
• FIG. 1A is an exploded perspective view of a preferred embodiment of the paired, expandable anastomosis device with guides.[0026]
• FIG. 1B is a perspective view of the anastomosis device depicted in FIG. 1A assembled and in the loading position.[0027]
• FIG. 1C is a cross-sectional view of the anastomosis device shown in FIG. 1B.[0028]
• FIG. 1D is a perspective view of the anastomosis device shown in FIGS. 1B with a graft vessel loaded onto the holding surface of the first expandable ring and a cutter positioned to be loaded into the lumen of the graft vessel.[0029]
• FIG. 2A is a cross-sectional view of the anastomosis device shown in FIG. 1A as anvil apparatus distends a target vessel into the anastomosis device.[0030]
• FIG. 2B is a cross-sectional view of the anastomosis device shown in FIG. 2A in the next phase as a cutter and an anvil are engaged to form an opening in the vessel.[0031]
• FIG. 2C is a partial cross-sectional view of the anastomosis device shown in FIG. 2B in the next phase as the graft vessel everts the portion of the target vessel defining the first vessel opening.[0032]
• FIG. 2D is a cross-sectional view of the anastomosis device shown in FIG. 2A in the next phase after the second compression plate has been compressed towards the first compression plate such that the everted graft vessel contacts the everted target vessel.[0033]
• FIG. 2E is a cross-sectional view of the anastomosis device shown in FIG. 2A with the anastomosed structure after the anvil apparatus and the cutter have been removed.[0034]
• FIG. 3A depicts an exploded perspective view of an embodiment of the present invention with locking extensions on one ring and corresponding slots in the other ring.[0035]
• FIG. 3B is a cross-sectional view of the embodiment shown in FIG. 3A in a loading position.[0036]
• FIG. 3C is a cross-sectional view of the embodiment shown in FIG. 3A in an anastomosis position.[0037]
• FIGS. 4A-4B are perspective views of an alternative embodiment of the anastomosis device having guides that are integral with one of the rings.[0038]
• FIGS. 5A-5F depict alternative embodiments of the expandable rings of the present invention.[0039]
• FIG. 6A is a partial cross-sectional view of the embodiment shown in FIG. 1A used in combination with an attachment actuation device.[0040]
• FIG. 6B is a perspective and partial cross-sectional view of the anastomosis device shown in FIG. 6A in the loading position.[0041]
• FIG. 6C is a cross-sectional view of the anastomosis device shown in FIG. 6B in the next phase after the first expandable ring has been compressed towards the second expandable ring by the attachment actuation device such that the everted graft vessel contacts the everted target vessel.[0042]
• FIG. 7A is a perspective view of the external anastomosis operator cooperating with the anvil depicted in phantom lines to form an anastomosis.[0043]
• FIG. 7B is a perspective view of an external anastomosis operator.[0044]
• FIG. 7C is an exploded perspective view of the external anastomosis operator.[0045]
• FIG. 7D is a cross-sectional view of the external anastomosis operator.[0046]
• FIG. 7E is a cross-sectional view of the external anastomosis operator as the anvil pull advancer knob is rotated to pull the anvil pull so that the anvil causes distension of the target vessel into the compression plate apparatus.[0047]
• FIG. 7F is a cross-sectional view of the external anastomosis operator as the attachment actuator device is moved to compress the second compression plate against the first compression plate.[0048]
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
• The present invention relates to a paired expandable anastomosis device adapted to join a first vessel opening in a first vessel to a second vessel opening in a second vessel. The anastomosis device is capable of expanding and contracting in response to changes in fluid pressure in the vessels that are joined together. The anastomosis device is also adapted to radially expand upon deployment, stretching the vessel tissue to create an anastomosis larger than the initial openings in the anastomosed vessels.[0049]
• As shown in FIG. 1A, the anastomosis device comprises a first expandable ring and a second expandable ring. The first expandable ring is adapted to hold a first vessel, such as a target vessel, at an opening in the vessel. The second expandable ring is adapted to hold a second vessel, such as a graft vessel, at an opening in the vessel. The rings cooperate with guides so that after the graft and target vessels have been loaded onto the rings, the second ring may be brought together with the first ring to create an anastomosis. Once the two rings have been brought together, the rings are adapted to be linked together so that the rings expand and contract in unison.[0050]
• [0051]Anastomosis device300 with guides and guideposts to link a pair of expandable rings together is shown at FIGS. 1A-1D. FIGS. 2A-2E depict the creation of an anastomosis opening in a vessel and the placement ofanastomosis device300 using anexternal operator700″. FIGS. 3A-3C depict an alternative embodiment of the anastomosis device having a ring with locking extensions positioned to slide into slots in the other ring. FIGS. 4A-4B depicts another embodiment of the anastomosis device in which one of the expandable rings is integral with a plurality of guides. FIGS. 5A-5F depict additional embodiments of the expandable rings. The anastomosis device may be used in combination with an attachment actuation device as depicted in FIGS. 6A-6C. Alternatively, the anastomosis device of the present invention may be utilized in combination with an attachment actuator of an external operator as depicted in FIGS. 7A-7F.
• In the embodiment shown in FIG. 1A,[0052]first ring310ais adapted to support a first vessel, such as atarget vessel20.First ring310ahas a generally annular shape and a plurality of holding surfaces or tabs514athat define an opening, first ring opening320a, which has a generally circumferential contour. The internal diameter of first ring opening320ais such that the corresponding portion of the vessel to be anastomosed can fit therein. First ring opening320ais generally round, however, the opening may also be ellipsoidal or ovoid.
• [0053]First ring310acomprises a plurality of connectedflexible segments324aeach with twoarms326ajoined by a flexible segment joint328a.Arms326aandflexible segment joints328aform V-shapedflexible segments324a. Eachflexible segment324ais attached to an adjoining flexible segment by a connecting joint322a.First ring310afurther includesguideposts330aadapted to slide into and frictionally engage withguides334. The operation of the guides and guideposts is discussed in more detail below.First ring310ahas afirst end370aand asecond end372aand defines a first ring opening320a.First ring310ais an example of a first ring means for providing support for a first vessel at a first vessel opening.
• As shown in FIG. 1A, holding[0054]tabs314aextend integrally fromfirst end370aat connectingjoints322a. Holding surfaces or tabs are intended to hold the everted contours of the structures being anastomosed. More particularly, a portion of the target vessel defining a vessel opening is everted throughring310aand held by holdingtabs314a. Each holdingtab314aextends radially inward and has a base315athat extends from the ring.Bases315apreferably curve radially inward with an U-shape. Holdingtabs314aare preferably wider atbases315athan at thetips316aopposite thebases315a. Tips316a-bare preferably rounded as shown to minimize the potential for penetration. Since, as discussed below, the anastomosis is generally completed immediately after the target vessel is loaded onto one of the rings, the holding tabs hold the target vessel long enough without additional anchors such as barbs or hooks. Holdingtabs314aare an example of holding means for holding the first vessel at the first vessel opening.
• Still referring to FIG. 1A,[0055]second ring310bis adapted to support a second vessel, such asgraft vessel50. The graft vessel may be synthetic or autologous.Second ring310bhas a plurality of holding surfaces ortabs314bthat define a second ring opening320bwith a round shape that corresponds to the shape of first ring opening320a. Like first ring opening320a, second ring opening320bis such that the corresponding portion of the graft vessel can fit therein, as shown in FIG. 1D. Note that while the configuration of the first and second rings are designed to specifically interact respectively with the target and graft vessel, all or part of their configurations can be reversed so that the first and second rings respectively interact with the graft vessel and target vessel.
• [0056]Second ring310bcomprises a plurality of connectedflexible segments324b, each with twoarms326bjoined by a flexible segment joint328b.Arms326bandflexible segment joints328bform V-shapedflexible segments324b. Eachflexible segment324bis attached to an adjoining flexible segment by a connecting joint322b.Second ring310bhas afirst end370band asecond end372b.Second ring310bis an example of a second ring means for providing support for a second vessel at a second vessel opening.
• Holding[0057]tabs314bextend integrally fromfirst end370batflexible segment joints328b. Holdingtabs314bare adapted to securely hold a portion of the graft vessel that defines an opening after the portion has been everted throughring310b. In the embodiment shown in FIGS. 1A-1D, each holdingtab314bhas a length that is about equal to the width ofsecond ring310b. Each holdingtab314bextends radially inward and has a base315bthat extends from the ring so that each holdingtab314bis opposite fromarms326bandguideposts330b.Bases315bare preferably U-shaped and curve radially inward toward the center of the expandable ring. The holding surfaces ortabs314bare preferably wider atbases315b, but narrower thanbases315aoffirst ring310a. As with the holding tabs of the first ring, holdingtabs314bpreferably terminate atrounded tips316bthat are rounded to minimize the potential for penetration. Holdingtabs314bare an example of holding means for holding the second vessel at the second vessel opening.
• Each[0058]holding tab314bofsecond ring310bhas a hook orbarb318 to preventgraft vessel50 from slipping off holdingsurfaces314baftergraft vessel50 has been loaded onto holdingtabs314b.Hooks318 are an example of anchor means for more securely anchoring a vessel on the holding means.
• [0059]Anastomosis device300 is shown in FIGS. 1B-1C in a loading position beforegraft vessel50 has been loaded onto holdingtabs314bofsecond ring310b. As shown in FIG. 1D, agraft vessel50 is loaded ontosecond ring310b. The graft vessel may be synthetic or auotologous.
• The holding surfaces such as holding tabs[0060]314a-bare preferably configured in a way such that they are not exposed to blood flowing through the anastomosed structures. Blood vessels have an internal layer, called the intimal layer and an external layer called the adventitial layer. The holding surfaces are positioned to capture everted tissue defining an opening in a blood vessel so that the holding surfaces and rings contact the adventitial layer of the blood vessel. When the rings are moved together, to an anastomosis position, the intimal layer of the portion of the first vessel defining a first vessel opening contacts the intimal layer of the portion of the second vessel defining a second vessel opening. Stated otherwise, the holding tabs contact only the exterior of the everted vessel tissue and no portion of the device is exposed in the vessel lumens.
• As shown in FIG. 1C, holding tabs[0061]314a-bare positioned such that as the rings are brought towards each other, each holdingtab314bis positioned opposite from the spaces between holdingtabs314ain a mated configuration. When referring to the relative configuration of the holding tabs in opposing rings, the terms “mated or interdigitated configuration” describe a configuration in which each one of the holding tabs in a ring can generally fit in or at least be opposite the space between two neighboring holding tabs in the opposing ring when such rings are close enough. While other configurations are possible, the holding tabs in each ring are preferably oriented relative to the holding tabs in the other ring in such a mating configuration. Examples of interdigitated configurations are provided below.
• As shown in FIG. 1A,[0062]anastomosis device300 further comprisesguides334 withguide apertures336.Guideposts330a-bof first and second rings310a-bare sized to slide intoguide apertures336.Guideposts330aoffirst ring310aextend from connectingjoints322a, opposite holdingtabs314a.Guideposts330bofsecond ring310bextend fromflexible segment joints328b. As shown in FIGS. 1B and IC, the rings are held in an initial loading position with the rings offset from each other by the use of the guides and guideposts.
• As shown in FIGS. 1B-1C, guides[0063]334 position rings310a-bin an initial loading position. In the initial loading position, the full length of eachguidepost330bofsecond ring310bhas been inserted intoguides334.Guideposts330aoffirst ring310aare partially inserted intoguides334 so that the rings are offset from each other. As shown in FIG. 1C, in the loading position, holdingtabs314aare sufficiently spaced apart from holdingtabs314bto permitgraft vessel50 to be everted throughring310band loaded onto holdingtabs314b. Additionally, in the loading position, holding tabs314a-bare sufficiently spaced apart so that the tissue defining an opening in the target vessel may be everted onto holdingtabs314aand brought into contact withgraft vessel50.
• [0064]Guides334 are positioned to provide guided coaxial movement of the rings relative to each other so that the target vessel may be brought into contact with the graft vessel.Guides334 permit the relative approach of the two rings asguideposts330aare moved intoguides334, bringingring310btowardsring310a. More particularly, guides334 enable rings310a-bto be brought together in a manner such thatsecond ring310bis moved in a fixed parallel orientation relative tofirst ring310a. In the anastomosis position, rings310a-bare compressed together and the graft vessel is anastomosed to the target vessel.Guides334 in combination withguideposts330a-bare an example of guide means for guiding the movement of one ring relative to the other ring.
• The guides also operate to structurally link the two rings together so that while the rings expand and contract, the anastomosis remains intact.[0065]Guide apertures336 are sized to frictionally engageguideposts330a-bso thatfirst ring310aand second ring310bremain in the anastomosis position, even as the rings expand and contract. More particularly, guideapertures334 are sized such that, after the rings are compressed together, significant force is required to move one ring away from the other ring. The frictional engagement ofguides334 withguideposts330a-balso enables rings310a-band the anastomosis to contract and expand in unison in response to change in fluid pressure through the target and graft vessels.Guides334 in combination withguideposts330a-bare examples of locking means for locking the first ring and second ring together such that the first vessel and the second vessel remain anastomosed together.
• To ensure sufficient compression of rings[0066]310a-b, guides334 andguideposts330 are preferably sized so that when rings310a-bare approximated to an anastomosis position, the holding tabs of one ring are sufficiently close to the holding tabs of the second ring to create a blood-tight anastomosis of the graft and target vessels. An example of a suitable compression is provided by an anastomosis device with holding tabs of a length such that the tips slightly extend into the space between the holding tabs of the opposite ring in an interdigitated configuration. The rings may also be designed for further compression such that holdings surfaces ortabs314bfurther enter the space between adjacent holding surfaces ortabs314a. Of course, the rings are preferably designed such that the rings are brought together without penetratingtarget vessel20 orgraft vessel50.
• Other interdigitated configurations are also possible. The rings may be designed so that when the rings are compressed together, the tips of the holding tabs of one of the rings terminate in approximately the same plane as the tips of the holding tabs of the other ring. Alternatively, the rings may be adapted such that, in the anastomosis position, the holding tabs of one ring are slightly offset from the holding tabs of the other ring. The rings are accordingly sized to have an anastomosis position that compresses down to the ideal spacing between the anastomosis sides while providing holding surfaces that have sufficient surface area to capture the tissue in an everted configuration.[0067]
• As can be seen from FIG. 1D, a[0068]graft vessel50 is loaded onto holding tabs314bof ring314 while acutter400 is positioned to be loaded into the lumen58 ofgraft vessel50.Cutter400 includes a cuttingtube410 that terminates at a cuttingknife412 with acutting edge414. Oncecutter400 is positioned withingraft vessel50 then the combination ofanastomosis device300,graft vessel50 andcutter400 are ready for use with anvil apparatus200 to form an anastomosis. This combination is referred to herein as ring and cutter assembly.
• FIGS. 2A-2E depict the use, in sequential order, of an[0069]anastomosis device300 in combination with acutter400,anvil210 and anattachment actuator600″ of anexternal operator700″. The operation of theexternal operator700″ is described in more detail below with reference to FIGS. 7A-7F. To optimally present this sequence, FIGS. 2A-2E are cross-sectional views.
• FIG. 2A depicts a[0070]graft vessel50, loaded ontoring310b. FIG. 2A also depictsanvil210 being pulled against the intima or interior of the vessel wall such thattarget vessel20 is sufficiently distended to permittarget vessel20 atanastomosis site10 to be pulled intoanastomosis device300 through first ring opening320a.Cutter400 also is shown in FIG. 2A extending through second ring opening320babout half way throughanastomosis device300 ascutter400 is approximated with the portion of thetarget vessel20 distended byanvil210.
• FIG. 2B depicts the formation of a first vessel opening[0071]24 in the wall of the first vessel.First vessel opening24 is formed by pulling anvil pull230 throughcutter400 with sufficient force to enableanvil210 to advancetarget vessel20 againstcutting edge414. After the cut has been made then a cut portion25 of the wall oftarget vessel20 remains on sphericalengaging end212 ofanvil210 while the portion26 of the target vessel that now definefirst vessel opening24 rests onanvil landing214.
• FIG. 2C depicts[0072]anastomosis device300 as it is being compressed and as portion26 definingvessel opening24 is being everted. FIGS. 2C-2D depict the rings being brought together by anattachment actuator600″ of anexternal operator700″. Attachment actuator has afirst ring engager600a″ and asecond ring engager600b″ adapted to hold first and second rings310a-bin a fixed orientation relative to each other and to bring rings together in this fixed orientation. In the embodiment shown in FIGS. 2A-2E,attachment actuactor600″ has actuating guides640″ that guide one ring engager toward the other ring engager to bring the expandable rings together. Eachring engager600a″-b″ has a latch (not shown) that enables the ring engagers to be released once the anastomosis is complete. The rings may, alternatively, be brought together by an attachment actuation device, which is described in more detail below with reference to FIGS. 6A-6C.
• Note that the everted[0073]portion56 ofgraft vessel50, more particularly theportion57 opposite runded tips316 of holdingtabs314b, is urged against portion26 that defines firsttarget vessel opening24 in a manner such that portion26 is being everted. This eversion process is augmented by landing214 ofanvil210 which allows portion26 to rest on landing214 and be plowed upward byeverted portion56. The length of portion26 is sufficient for this eversion process sincevessel20 was distended and pulled into the snap-fit anastomosis device by the action ofanvil210.
• FIG. 2D depicts[0074]anastomosis device300 after compression. More particularly,ring310bhas been moved towardring310aby slidingguideposts330bon guides334. Note that the evertedportion56 ofgraft vessel50, more particularly theportion57 opposite from the roundedtip316b, is urged against portion26 that defines firsttarget vessel opening24 in a manner such that portion26 has been everted. The end result is that theportion27 opposite from roundedtip316ais held in contact with theportion57 ofvessel50 opposite from distalrounded tip316b.
• During anastomosis, the rings are preferably held in an initial, radially compressed position by[0075]attachment actuator600″ ofexternal operator700″ orattachment actuation device600′. In this radially compressed position, each ring opening has an initial diameter. Once the vessels are anastomosed together, the rings are released by the attachment actuator and spring radially to a deployed position. In the deployed position, the rings have a greater diameter, stretching the vessel openings at the anastomosis site.
• This radial expansion is best seen in FIGS. 2D-2E. The rings preferably spring open sufficiently so that, at the anastomosis site, the vessel openings have a diameter equal to or greater than the diameter of the graft vessel, thus minimizing restriction at the anastomosis. For example, for a graft vessel having a diameter of about 5 mm the initial diameter of the ring openings may be about 4 mm and the diameter of the ring openings after deployment may be about 6 mm. As shown in FIG. 2D,[0076]external operator700 holds rings310a-bin an initial state with a diameter D1. When anastomosis is complete andexternal operator700releases anastomosis device300, rings310a-bradially expand to a greater diameter, D2, as shown in FIG. 2E.
• After rings[0077]310a-bhave been brought together to join portion26 oftarget vessel20 that defines first vessel opening24 toportion56 ofsecond vessel50 that defines graft vessel opening54, thenfirst vessel20 andsecond vessel50 are anastomosed together and are in fluid communication. Note that holding tabs314a-bhold the vessels in place without penetration and without contacting the interior of the vessels. Anvil apparatus200 andcutter400 have been removed upon the completion of the procedure through lumen58 ofgraft vessel50. Once the anastomosis is complete,guideposts330a-bremain stationary inguides334 after being compressed due to frictional engagement.
• There are significant advantages to combining vessels in accordance with the device described above, especially in a manner such that there is at least partial eversion and contact between the everted surfaces of the vessels. Another advantage is that there is no penetration of the portions of the vessels defining the vessel openings or at least no penetration of the target vessel. Of course, the anastomosis is fluid tight to normal systolic pressure and remains intact under stress. Since the everted[0078]portions26 and56 respectively cover the holding tabs314a-b, exposure of subintimal connective tissue is minimized. The rings create an anastomosis that is morphologically satisfactory, including complete eversion of the receiving target vessel intima with apposition to the graft vessel. Further, evertedportions26 and56 are in intima-intima contact and no cut portion is significantly exposed to the blood flow that is to circulate through the anastomosed structures.
• Furthermore, the rings create an anastomosis without any placing any foreign material into the anastomosed vessels and the interior of the vessels are not exposed to any foreign material. As a result, the thrombogenic potential is minimized.[0079]
• Also, as discussed above, the rings radially expand upon initial deployment. The radial expansion of the rings enables the anastomosis to have a diameter that is larger than the initial opening in the vessel. It may expand enough to be equivalent to the diameter of the anastomosed vessels. Thus, a smaller incision in the target vessel is required. Because a smaller incision is required, smaller instruments may be used to create the opening in the target vessel and to place the anastomosis device. For example, the anvil and the cutter may be smaller than would otherwise be required. As a result the invasiveness of the procedure is minimized. By radially expanding upon release to create an opening at least equal in diameter to the graft vessel, the present invention also minimizes the restriction at the anastomosis and potential resulting complications such as thrombosis and neointimal hyperplasia.[0080]
• The rings are also capable of expanding and contracting with changes in the fluid pressure in the anastomosed vessels. For example an anastomosis device which joins two blood vessels will expand and contract with systole and diastole. The rings can expand and contract while the holding tabs maintain the anastomosis. By expanding and contracting with changes in fluid pressure, the anastomosis device of the present invention minimizes flow disturbances as the blood flow approaches the anastomosis site. This feature also serves to minimize thrombosis and neointimal hyperplasia.[0081]
• In addition to the results achieved, there are also significant procedural advantages. The method does not require temporary occlusion of blood flow to the target vessel. The second ring may be pre-loaded with the graft vessel so that the steps disclosed above in connection with FIGS. 2A-2E may be accomplished simultaneously or in quick succession. By pre-loading the graft vessel and simultaneously cutting a target vessel opening and loading the target vessel, the rings may be brought together to create the anastomosis without blocking blood flow through the target vessel. Also, the anastomosis can be reliably created. The anastomosis utilizing the paired rings of the present invention is rapidly achieved and eliminates the need for highly skilled suturing. For example, once the anvil pull extends through the wall of the vessel, the anastomosis procedure can be accomplished in as little as 30 seconds when rings[0082]310a-bare used to join the vessels.
• Manual manipulation may be utilized to achieve the steps shown in FIGS. 2A-2E, however, mechanization is preferred. More particularly, anvil pull[0083]230 may be manually pulled ascutter400 is held or manually advanced. Additionally, the anastomosis device may be manually compressed in some embodiments. However, the paired rings of the present invention are preferably used in combination with an intraluminally directed anvil apparatus such as the apparatus disclosed in U.S. Pat. No. 6,248,117, which is hereby incorporated by reference. Other intraluminally directed anvil apparatus are disclosed in U.S. patent application Ser No. 09/737,200 and Serial No. 09/460,740 which were previously incorporated by reference. The paired rings may also be used in combination with an externally directed apparatus, such as those disclosed in U.S. patent application Ser. No. 09/736,781, filed Dec. 14, 2000 and entitled Externally Directed Methods for Forming an Anastomosis Opening in a Vessel, U.S. patent application Ser. No.______ filed on Oct. 31, 2001 and entitled Soft Anvil Apparatus for cutting Anastomosis Fenestra, and U.S. patent application Ser. No.______ filed on Oct. 31, 2001 and entitled Externally Positioned Anvil Apparatus for Cutting Anastomosis Fenestra, which are hereby incorporated by reference. Alternatively, the anastomosis device may be used in combination with any suitable mechanical anastomosis techniques.
• FIGS. 3A-3C depict an alternative embodiment of the anastomosis device, referred to herein as[0084]anastomosis device300′. The two rings ofanastomosis device300′ are structurally linked by lockingextensions340 in combination withslots346. As shown in FIGS. 3A-3B, each lockingleg330a′ offirst ring310a′ has alocking extension340. As shown in FIG. 3C, each lockingextension340 is positioned to lock into acorresponding slot346 in a lockingleg330b′ when rings310a′-b′ are brought together to the anastomosis position.Legs330b′ havingslots346 in combination withlegs330a′ having lockingextensions340 are additional examples of locking means for locking the first ring and second ring together such that the first vessel and the second vessel remain anastomosed together. Alternatively, the expandable rings may be linked by any suitable device, such as clips, clamps or interlocking tabs. Sutures or adhesive may also be used to structurally link two rings together. Clips, clamps, interlocking tabs, sutures and adhesives are all further examples of locking means for locking the first ring and second ring together such that the first vessel and the second vessel remain anastomosed together.
• As shown in FIGS. 3A-3C,[0085]anastomosis device300′ functions without guides such as the guides of the embodiment shown in FIG. 1A. Instead, rings310a′-b′ ofanastomosis device300′ are adapted to be coupled by anattachment actuation device600′ as shown in FIGS. 6A-6C orattachment actuator600 ofexternal operator700 as shown in FIGS. 7A-7E, both of which are discussed in more detail below.Attachment actuator600 andattachment actuation device600′ have afirst ring engager600a,600a′ and asecond ring engager600,600b′ that are adapted to guide rings310a-bfrom a loading position to an anastomosis position.
• FIGS. 4A-4B depict an additional embodiment of the anastomosis device, referred to herein as[0086]anastomosis device300″.Guides334″ ofanastomosis device300″ are integral withsecond ring310b″ and have holdingsurfaces314b.Second ring310b″ is preferably made of plastic and integrally molded withguides334.Ring310b″ enables graft vessel tissue to be everted throughring310b″ and over holdingsurfaces314b″.
• [0087]Ring310a″ hasguideposts330″ positioned to slide intoguides334″.Guides334″ haveapertures336″ that are sized to frictionally engageguideposts330″. FIG. 4B depicts a partial cross-section of agraft vessel50 in phantom lines.Guideposts330″ in combination withguides334″ are an additional example of locking means for locking the first ring and second ring together such that the first vessel and the second vessel remain anastomosed together.
• The graft vessel is everted through[0088]ring310b″ and over holdingsurfaces314b″. In the embodiment shown in FIG. 4B,ring310bis designed such that the graft tissue is everted throughring310bover holdingsurfaces314band onto the outer surface ofguides334″. In this embodiment,guideposts330a″ are adapted to penetrate graft vessel tissue that has been everted throughsecond ring310b′ andpast guide apertures336″. After the graft vessel is loaded ontosecond ring310b,guideposts330a″ penetrate the graft vessel and slide partially intoguides apertures336″.Guideposts330″ in combination withguides334″ are an additional example of anchor means for more securely anchoring a vessel on the holding means.
• As shown in FIGS. 4A-4B, holding[0089]surfaces314b″ are at the top ofguides334″. As shown in FIG. 3A, each holdingsurface314b″ is a flat surface. Holding surfaces314a″-b″ ofrings310a″-b″ ofanastomosis device300″ are arranged so that when rings310a″-b″ are brought together to an anastomosis position, holdingtab tips316a″ offirst ring310a″ directly oppose holdingsurface314b″ ofsecond ring310b″. Therefore, the graft and target vessels are pinched betweentips316a″ and holdingsurfaces314b″when rings310a″-b″ are in the anastomosis position.
• Holding surfaces, such as holding tabs[0090]314a-bdepicted in FIG. 1A and holdingsurfaces314b″ depicted in FIG. 4A, can have a variety of shapes and arrays. A generally regular distribution on the anastomosis sides of rings310a-bis preferred. Holding surfaces may also form a contiguous surface around a ring. For example, a suitable elastic band may be utilized as a ring having a contiguous surface.
• In an alternative embodiment, the holding tabs are inclined towards the ring so that each holding tab clamps vessel tissue against the ring. In another embodiment, holding tabs of one of the rings are spike shaped or have pointed tips to better retain the graft vessel. The holding tabs are typically rather rigid, however, they may also be designed to elastically bend in such a way that the distal tips of such holding surfaces slightly swing about their respective bases.[0091]
• The number of holding surfaces and their spacing may be varied as needed as long as the portions of the vessels defining the vessel openings can be maintained in an everted orientation. For example, the plurality of holding surfaces may include ten holding surfaces or tabs as shown in FIG. 1A. However, smaller or greater amounts may also be utilized, for example there may be from three to sixteen holding surfaces.[0092]
• The guides may also be distributed in varying numbers and arrays. The guides may be movably connected to the rings. Alternatively, the guides may be integral with one of the rings. The anastomosis devices depicted in FIGS. 1A and 4A have ten guides. Alternative embodiments may include only two or more guides. The guides may extend from one or both of the rings at any appropriate location. The guides are preferably regularly distributed around the ring. Furthermore, the guides are preferably situated such that the portion defining the target vessel opening and the portion defining the graft vessel opening are joined without being penetrated as the first vessel and the second vessel are anastomosed together.[0093]
• As depicted in FIGS. 5A-5E, the rings of the present invention may have flexible segments with a variety of shapes. The expandable rings may be formed of any shape of flexible segment that provides the rings with the capability to expand and contract with changes in fluid pressure. FIGS. 5A-5C depict alternative embodiments of the second ring. FIG. 5A is a partial view of V-shaped flexible segments[0094]324 of thesecond ring310adepicted in FIG. 1A. FIG. 5B depicts an expandable ring that comprises a series of U-shaped flexible segments. FIG. 5C depicts an expandable ring comprising a series of flexible segments which are made of plastic and have hinged portions of decreased thickness relative to adjacent portions.
• FIGS. 5D-5F depict embodiments of the first ring with varied flexible segments. FIGS. 5D depicts an expandable ring with U-shaped flexible segments. FIG. 5E shows a ring comprising flexible segments which have a configuration that is diamond shaped. The diamond shaped configuration is an example of a quadrilaterial configuration. FIG. 5F depicts an expandable ring with circular flexible segments. Alternatively, the rings may include spiral-shaped flexible segments, oval-shaped flexible segments, elliptical flexible segments and other flexible segments that have appropriate configurations.[0095]
• The positioning of the anastomosis device and the operations of pulling or holding anvil pull[0096]230, making an opening, and compressing the rings together, as described in connection with FIGS. 2A-2E, can be accomplished manually or with the aid of devices such asexternal anastomosis operator700. The attachment actuation means need not be part of the same apparatus with the anvil pull engager and the cutter. This reduces the size of the instruments utilized.
• FIGS. 6A-6C show an attachment actuation device or[0097]tongs600′ used to approximate rings310a-b.Actuation device600′ has opposing ring engagers, afirst ring engager600a′ and asecond ring engager600b′, that respectively extend from attachedhandles604a-b.Handles604a-bare connected together at a hinge. Eachring engager600a′-b′ has a latch608a-bthat enables the ring engagers to lock onto expandable rings310a-bso thatanvil210 can be pulled through second ring opening320band distend the wall ofvessel20 intoexpandable anastomosis device300. While the tissue ofvessel20 is cut and everted onto holdingsurfaces314b, tongs600′ are closed. Once the anastomosis is complete, latch608a′-b′ is released to openring engagers600a′-b′ and deploy expandable rings310a-b.Attachment actuation device600′ is an example of attachment actuation means for approximating one ring to the other ring.Latches608a′-b′ are examples of means for locking the ring engagers against the rings.
• FIG. 7A shows[0098]external anastomosis operator700 with anattachment actuator600 engaging an anvil in preparation for cutting an opening in the target vessel. As shown in FIGS. 7A-7B,external anastomosis operator700 has abody710 with anoptional handle720. Attached tobody710 are the main components ofoperator700. These main components arecutter400,spring biasing device450, ananvil pull engager500 which includes ananvil pull holder530 and ananvil pull advancer560, and anattachment actuator600.Attachment actuator600 is an additional example of attachment actuation means for approximating one of the rings to the other ring.
• The attachment actuation devices and the[0099]attachment actuator600 ofexternal operator700 may be adapted to enable the orientation of the rings relative to each other to remain essentially the same as the rings are brought together to an anastomosis position. This ability may be necessary for embodiments of the anastomosis device such asdevice300′ that has no guides. Note that once the opposing ring engagers of the attachment actuation devices or theattachment actuator600 ofexternal operator700 have have engaged the rings of an anstomosis device, preferably in a locked configuration, then the rings are easily brought together while maintaining their relative orientation. Note that the opposing ring engagers may be guided together in different ways as shown by the various embodiments. For example,attachment actuation device600″ relies onguides640″ to bringfirst ring engager600a″ andsecond ring engager600b″ together. The hinge ofattachment actuation device600′ guides the opposingring engagers600a′-b′ together. As discussed below in reference toattachment actuator600,rail640 guides the movement of ring engager to the other. Mechanims adapted to lock the ring engagers against the rings are also discussed below in reference toattachment actuator600 that function much likelatches608a′-b′ discussed above in reference toattachment actuation device600′.
• FIG. 7B provides a perspective view of an[0100]external anastomosis operator700 with its main components identified including:cutter400,spring biasing device450, ananvil pull engager500 which includes ananvil pull holder530 and ananvil pull advancer560, and anattachment actuation device600.Spring biasing device450 is used to apply pressure against thedistal end418 ofcutter400. One advantage derived form the use of a device such asexternal anastomosis operator700 is that such devices have a series of actuators, and by manipulating these actuators the operator can effectuate the different operations at the anastomosis site without actually having to manually and directly operate each element itself.
• FIG. 7C provides an exploded perspective view of all of the components of[0101]external anastomosis operator700 so it is with reference primarily to this view that the details ofoperator700 are understood. FIGS. 7D-7E provide cross-sectional views ofoperator700 depicting the steps for usingoperator700.
• [0102]Cutter400 is shown in FIG. 7C as including atip portion401 and anextension portion402. Aspring biasing device450 applies pressure against thedistal end418 ofcutter400.Spring biasing device450 has aspring mount452 that is mounted tobody710 via spring mount pins454. Arotatable spring housing456 is threadably engaged byspring mount452. Loaded intorotatable spring housing456 is acutter cup458 that is configured to holddistal end418 of cutter.Cutter cup458 has a flange that is pushed against a flange at the proximal end ofrotatable spring housing456 such thatcutter cup458 is held in the proximal end ofspring housing456. Aspring460 is positioned within aspring sleeve462.Spring460 andspring sleeve462 have ends thatabut cutter cup458 and opposite ends that abut threadedjam screw464. Threadedjam screw464 is accessible via the distal end ofspring mount452 so that it may be rotated to increase or decrease the tension ofspring460 againstcutter cup458.
• [0103]Cutter cup458 moves withinrotatable spring housing456 againstspring460. The pressure ofspring460 againstcutter cup458 enablescutter400 to apply pressure againstanvil210 asanvil210 is pulled againstcutter400. This makes it easier to cut the vessels as force is being applied in both directions. It also enablescutter400 to be pushed back byanvil210 to allowanvil210 to further distend the wall ofvessel20 as shown in FIGS. 5A-5B until sufficient pressure is applied byspring460 tobias cutter400 forward and by the advancement ofanvil210 by anvil pull230 to cut the vessel. The gradual increase in pressure also serves to assist a sphericalengaging end212 ofanvil210 to self center oncutter400. More particularly,anvil210 may be initially misaligned such that the center of engaging end from which anvil pull extends is positioned on the cutting edge of the cutter. A rapid application of pressure would lock such a misalignment while a gradual increase enables the curvature of spherical engaging end to guide the anvil into a centered orientation.
• Another function of spring biasing device is to set the position of[0104]cutter400.Rotatable spring housing456 has anotch457 at its distal end that enables a screw driver to rotaterotatable spring housing456 withinspring mount452 to advance or retractrotatable spring housing456 withinspring mount452. Movement ofrotatable spring housing456 also movescutter cup458, thereby determining the location ofdistal end418 ofcutter400 withinoperator700. Of course advancement ofcutter cup458 towards the proximal end ofoperator700causes cutting knife400 to engageanvil210 closer tofirst ring310awhile retraction ofcutter cup458 towards the distal end ofoperator700 causes cutting knife and anvil to engage each other closer tosecond ring310b. The position ofcutter400 is preferably set to enablevessel20 to be distended in a manner that is optimal for then subsequently everting the portion defining the newly formed opening onto holdingsurfaces314a. To carefully identify the length thatrotatable spring housing456 is advanced or retracted, adetent470 is threaded into spring mount such that it can contact rotatable spring housing and engage thegrooves471 of rotatable spring housing in a manner that enablesdetent470 to click as each groove is rotatedpast detent470.
• Obviously[0105]spring biasing device450 has many variables that impact the manner in whichcutter400 is used in combination withexternal anastomosis operator700. Some of these variables include the inherent tension ofspring460, the tension ofspring460 as caused by the position of threadedjam screw464 inspring mount452 againstspring460, and the position of the surface whichdistal end418 ofcutter400 abuts, namely cutter cup660 as determined by the position ofrotatable spring housing456 withinspring mount452.
• [0106]Spring biasing device450 is an example of spring biasing means for providing tension against the cutting means as the cutting means engages the anvil means of the intraluminally directed anvil apparatus. The spring biasing means provides an amount of tension that enables the cutting means to form the first vessel opening after the wall of the first vessel has been distended by the action of the anvil means being pulled into the openings of the ring assembly such that forming the first vessel opening results in at least partial eversion of the portion of the first vessel defining the first vessel opening.
• As indicated above,[0107]anvil pull engager500 has two primary components including ananvil pull holder530 and anvil pull advancer. Anvil pullholder530 receives anvil pull230 viaspring biasing device450. More particularly, anvil pull230 extends throughcutter cup458,rotatable spring housing456,spring460 andsleeve462 aroundspring460, and out of threadedjam screw464.
• [0108]Anvil pull holder530 includes aholder mount532 positioned intrack730 ofbody710. In this embodiment, holder mount is moveable so that the anvil pull can be advanced after it is held. However, in other embodiments, the anvil pull holder may just lock the anvil pull into position such that the cutter is moved against a stationary anvil. Similarly, thespring biasing device450 may be eliminated so that the vessel is cut only by pressure exerted by the anvil pull against the cutter. As discussed above, while the cutter and the anvil may engage each other in these arrangements, it is preferable for the cutter to apply some pressure as the anvil pull is advanced against the cutter.
• [0109]Holder mount532 may be utilized in different ways to hold anvil pull230.Holder530 has asplit cone534 inserted into a tapered chamber536 against aspring538. Anvil pull230 extends through apertures inholder mount532,spring538, splitcone534 and out of an aperture centered inholder knob540.Holder knob540 is threadably engaged byholder mount532 such that rotation ofholder knob540 advances splitcone534 in tapered chamber536 causing split cone to lock ontoanvil pull230. Holder mount is slotted at its distal end as is holder knob. By aligning slot542 ofholder knob540 with the insert slot544 of holder mount, anvil pull230 can be bent so that it extends through both holder knob slot542 and insert slot544. Thenholder knob540 can then be rotated so that the bent portion of anvil pull230 is rotated into one of the locking slots546a-bthat extend perpendicularly from insert slot544. This securely locks anvil pull into position. Anvil pull230 can be locked through the use of slots instead of or in addition to the use ofsplit cone534 in tapered chamber536.
• Since[0110]anvil pull holder530 is moveable it threadably engages rotatablelead screw562 of anvil pull advancer. More particularly,lead screw562 is threadably engaged byanti-backlash nut550 which is fixedly attached toholder mount532.Anti-backlash nut550 has anattachment face552 through which a plurality of attachment face screws554 extend to holdholder mount532 andanti-backlash nut550 together.
• [0111]Lead screw562 has aproximal pivot end564 that rotates within abushing566 positioned within a recess inspring mount452. Lead screw also has a distal pivot end568 that is attached toadvancer knob570 to rotatelead screw562.Advancer knob570 rotates within anadvancer knob mount572 which is attached tobody710 ingroove730 via advancer knob mountbolts574. As shown in FIG. 7D, distal pivot end568 rotates in a bushing576 positioned within an aperture ofadvancer knob mount572.
• Advancer[0112]knob570 has a stem with a plurality ofgrooves578 that engage a detent580 to click so that the incremental rotation ofadvancer knob570 can be carefully counted to determine the length that the anvil is moved in the anastomosis device as the anvil pull is advanced. As shown in FIG. 7C, detent580 is threaded intoadvancer knob mount572 such that it can contactgrooves578 in the stem ofadvancer knob570 to click as each groove is rotated past detent580.
• FIG. 7E depicts[0113]advancer knob570 being rotated to move anvil pull advancer560 so that it can urge anvil pull230 in a manner such thatanvil210 is advanced withinanastomosis device300. Asadvancer knob570 is rotated,lead screw562 is thereby rotated. Sinceanvil pull holder530 is threadably engaged on rotatablelead screw562 and is locked intrack730,anvil pull holder530 can only move forward and backward aslead screw562 is rotated.
• FIG. 7F depicts[0114]attachment actuation device600 being engaged.Attachment actuation device600 has afirst ring engager600aand asecond ring engager600b.First ring engager600aand asecond ring engager600beach respectively utilize an optional adaptor610a-bto engage first and second rings310a-b.First ring engager600aandsecond ring engager600beach have acutter aperture620aand620b.Cutter400 extends through these aligned apertures620a-b.First ring engager600ais positioned onrail640 such that it extends slightly beyond cuttingedge414 ofcutter400. This difference in length enables first ring300ato be held slightly beyond cutter in a manner that permits the wall ofvessel20 to be pulled into anastomosis device as shown in FIG. 7D-7F and distended as needed.
• [0115]Rail640 is attached tobody710 viarail pin642. Agroove pin644 extends throughrail640. Afirst ring holder646 holdsfirst ring engager600aon the proximal end ofrail640.
• [0116]First ring engager600ais fixedly mounted onrail640 viapin646 whilesecond ring engager600bis movably mounted onrail640.Second ring engager600bhas agroove634 through whichgroove pin644 extends. The configuration ofgroove pin644 ingroove634 enablessecond ring engager600bto be held in a fixed orientation such that it can be moved back and forth as needed with respect tofirst ring engager600a.
• Second ring engager is moved on[0117]rail640 by rotating threadedcompressor sleeve650 which engages a threaded rail sleeve648. Threaded rail sleeve648 may be adhered ontorail640 or be an integral component.Rail640 and its threaded rail sleeve648 or threaded rail portion combined withcompressor sleeve650 are means for advancing one ring engager towards the other ring engager.
• Set[0118]screws615 lockfirst ring engager600aonfirst ring310a.Second ring engager600bhas a latch (not shown) that enables engager600bto lock ontosecond ring310b. Once the anastomosis is complete, setscrews615 and the latch are released to release the first and second ring engagers from the expandable rings. Note that there are many other ways for locking the rings with first andsecond ring engager600a-bsuch as the use of conventional quick release configurations. Quick release configurations, latches and set screws are all examples of means for locking the ring engagers against the rings.
• The paired expandable anastomosis device of the present invention is preferably used for vascular anastomosis, however, the present invention is not limited to such use. Nor is the anastomosis device limited to use with any particularly sized vessel. For example, vessels may be joined with diameters ranging from about 2 mm to about 20 mm, but there is no fundamental limitation for using embodiments of this invention with graft vessels with diameters less than 2 mm.[0119]
• It will be obvious to those having skill in the art that many changes may be made to the details of the above-described embodiments of this invention without departing from the underlying principles thereof. The scope of the present invention should, therefore, be determined only by the following claims.[0120]

Claims (20)

1. A paired anastomosis device for holding a first vessel together with a second vessel comprising:

first ring means for providing support for a first vessel at a first vessel opening, wherein the first ring means has a first ring opening,

second ring means for providing support for a second vessel at a second vessel opening, wherein the second ring means has a second ring opening,

wherein each ring means is adapted to expand and contract to enable each respective vessel opening to change in diameter, and

wherein the ring means are configured to be structurally linked in a manner such that the first and second ring means expand and contract in unison and such that the first vessel remains anastomosed to the second vessel at the first and second vessel openings as the first and second ring means expand and contract.

2. The anastomosis device ofclaim 1, further comprising locking means for locking the first ring means and the second ring means together such that the first vessel and the second vessel remain anastomosed together.

3. The anastomosis device ofclaim 2, wherein the locking means comprises guide means for guiding the movement of one ring means relative to the other ring means from a loading position with the first ring means offset from the second ring means to an anastomosis position.

4. The anastomosis device ofclaim 2, wherein the first and second ring means are adapted to cooperate with attachment actuation means for approximating one of the ring means to the other ring means such that the device is moved from a loading position to an anastomosis position.

5. The anastomosis device ofclaim 1, wherein the first ring means further comprises holding means for holding the first vessel at the first vessel opening, and

wherein the second ring means further comprises holding means for holding the second vessel at the second vessel opening.

6. The anastomosis device ofclaim 5, wherein the holding means of at least one of the rings means has anchor means for more securely anchoring a vessel on the holding means.

7. A paired anastomosis device for holding a first vessel together with a second vessel comprising:

a first ring having holding surfaces that define a first ring opening, wherein the holding surfaces are adapted to hold a portion of a first vessel defining a first vessel opening such that the first vessel opening is at the first ring opening,

a second ring having a plurality of holding surfaces that define a second ring opening, wherein the holding surfaces are adapted to hold a portion of a second vessel defining a second vessel opening such that the second vessel opening is at the second ring opening,

wherein each ring is adapted to expand and contract to enable each respective vessel opening to change in diameter, and

wherein the rings are configured to be structurally linked in a manner such that the first and second rings expand and contract in unison and such that the first vessel remains anastomosed to the second vessel at the first and second vessel openings as the first and second rings expand and contract.

8. The anastomosis device ofclaim 7, further comprising a plurality of guideposts extending from one of the rings and a plurality of guides fixedly connected to the other ring, wherein the guideposts are positioned to slide into the guides in order to guide the rings from a loading position to an anastomosis position.

9. The anastomosis device ofclaim 8, wherein the guides are sized to frictionally engage the guideposts such that the rings are maintained in the anastomosis position after the rings are brought together.

10. The anastomosis device ofclaim 7, wherein one of the rings has a plurality of legs with locking extensions and the opposite ring has a plurality of legs with slots positioned to receive the locking extensions, such that the rings are maintained in the anastomosis position after the rings are brought together.

11. The anastomosis device ofclaim 7, wherein each vessel has an intimal layer, and

wherein the holding surfaces of each ring are positioned to capture vessel tissue in an everted configuration so that when the rings are in an anastomosis position the intimal layer of the portion of the first vessel defining a first vessel opening contacts the inimal layer of the portion of the second vessel defining a second vessel opening.

12. The paired anastomosis device ofclaim 7, wherein each vessel has an adventitial layer,

wherein the holding surfaces of the first ring contact the adventital surfaces of the portion of the first vessel defining a first vessel opening, and

wherein the holding surfaces of the second ring contact the adventital surfaces of the portion of the second vessel defining a second vessel opening.

13. The anastomosis device ofclaim 7, wherein each ring comprises a plurality of flexible segments.

14. The anastomosis device ofclaim 13, wherein each flexible segment comprises two adjoining arms in a V-shaped configuration.

15. The anastomosis device ofclaim 13, wherein each flexible segment has a configuration that is selected from the group consisting of a U-shaped configuration, a quadrilateral shaped configuration, a circular configuration, an elliptical configuration, a spiral-shaped configuration, and an oval-shaped configuration.

16. The anastomosis device ofclaim 13, wherein the holding surfaces of each ring are holding tabs.

17. The anastomosis device ofclaim 16, wherein each flexible segment of the plurality of flexible segments of each ring is adjoined to an adjacent flexible segment by a connecting joint, wherein each flexible segment of each ring has a flexible segment joint, wherein the holding tabs of the first ring extend from the connecting joints, wherein the holding tabs of the second ring extend from the flexible segment joints.

18. A paired anastomosis device for holding a first vessel together with a second vessel comprising:

first ring means for providing support for a first vessel at a first vessel opening, wherein the first ring means has a first ring opening,

second ring means for providing support for a second vessel at a second vessel opening, wherein the second ring means has a second ring opening,

wherein each ring means is adapted to be in a compressed position as the first vessel and second vessel are anastomosed together such that each respective ring opening and respective vessel opening have an initial diameter, and

wherein at least one ring means is adapted to radially expand to a deployed position after the first vessel and second vessel are anastomosed together such that each ring means and vessel opening has a greater diameter than the initial diameter of each respective ring means and vessel opening.

19. A paired anastomosis device for holding a first vessel together with a second vessel comprising:

a first ring having holding surfaces that define a first ring opening, wherein the holding surfaces are adapted to hold a portion of a first vessel defining a first vessel opening such that the first vessel opening is at the first ring opening,

a second ring having a plurality of holding surfaces that define a second ring opening, wherein the holding surfaces are adapted to hold a portion of a second vessel defining a second vessel opening such that the second vessel opening is at the second ring opening,

wherein each ring is adapted to be in a compressed position as the first vessel and second vessel are anastomosed together such that each respective ring opening and respective vessel opening have an initial diameter, and

wherein at least one ring is adapted to radially expand to a deployed position after the first vessel and second vessel are anastomosed together such that each ring and vessel opening has a greater diameter than the initial diameter of each respective ring and vessel opening.

20. A paired anastomosis device for holding a first vessel together with a second vessel comprising:

a first ring having a plurality of holding surfaces that define a first ring opening, wherein the holding surfaces are adapted to hold a portion of a first vessel defining a first vessel opening such that the first vessel opening is at the first ring opening,

a second ring having a plurality of holding surfaces that define a second ring opening, wherein the holding surfaces are adapted to hold a portion of a second vessel defining a second vessel opening such that the second vessel opening is at the second ring opening,

wherein each ring has a plurality of flexible segments from which the respective holding surfaces extend, and

guides positioned to provide guided coaxial movement of the rings relative to each other so that the rings can be moved from a loaded position with the first ring offset from the second ring to an anastomosis position with the first vessel is anastomosed to the second vessel at the first and second vessel openings,

wherein the plurality of flexible segments of each ring are adapted to enable each respective ring opening and respective vessel opening to change in diameter as each ring expands and contracts in response to changes in fluid pressure.

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