Abstract:
A vascular closure device comprising a retrievable sheath-delivered contractible, clip device with structural radial or terminal members with terminal and non-terminal hooks that engage the vessel wall. Unlike other vascular closure clips, this device is delivered on the outside rather than the inside of sheath. Closure of the tissue opening can be effected by the feet of the clip engaging the puncture, aperture, or wound edges and memory characteristics of the device cause a contraction of the members, bringing the members into apposition and the wound edges together, permitting immediate vascular closure and healing of the blood vessel. The device can be delivered and recovered by an intravascular sheath.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority to U.S. provisional application 60/711,279, filed Aug. 24, 2005, and is a continuation-in-part of U.S. utility application Ser. No. 11/316,775, filed Dec. 23, 2005, now abandoned each of which is incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to methods and apparatuses for closing punctures and apertures in human and animal tissue and to methods and apparatuses for inserting such an apparatus into such tissue to perform such closure functions. 
     BACKGROUND 
     During angiography and related procedures, catheters are inserted through an incision or puncture in the skin and underlying tissues to access an artery or vein, typically in the groin, neck, or subclavian areas of a patient. The catheter can be inserted through a puncture in the blood vessel and guided to the desired site to perform interventional procedures such as angiography, angioplasty, plaque removal, and infusion of a therapeutic substance. After the procedure is completed and the catheter is removed from the patient, the access hole must be closed to prevent massive hemorrhage. This is conventionally achieved by applying pressure over the blood vessel manually and then by applying a pressure bandage, compressive weight, or clamp device. With conventional methods, the rate of post-puncture hemorrhage is high, which causes considerable complications. This complication is exacerbated by the concomitant use of anticoagulant medications such as heparin or warfarin and by antiplatelet drugs, which are commonly used to treat vascular disease. 
     Sutures have been used to close access puncture wounds in blood vessels. U.S. Ser. No. 05/613,974 describes a device and method for applying sutures to a vascular puncture. US2004/0093027A1 describes barbed suture-like material that apposes the puncture site. US2005/0121042 A1 describes a device and method for applying suture to a vascular puncture. Difficulties with these methods include the large number of steps necessary to deploy the needles, capture the suture, withdraw the suture, tie the knot, and cut the suture. In addition, the hole in the blood vessel is often widened by insertion of the instrument, and the suture remains intravascularly on the endothelial surface, and thus can be a nidus for thrombus or intravascular mural hyperplasia with later spontaneous and catastrophic closure of the vessel. 
     Extravascular plugs have also been proposed for closure of vascular punctures. U.S. Ser. No. 05/254,105 and U.S. Ser. No. 05/330,445 describe an extravascular plug which is slid down the external surface of the catheter or introducer and is placed into the puncture site in this manner. U.S. Ser. No. 05/643,318 relates to a similar device that has its own vessel locator device. US22022822A1 and US2004/0158287A1 describe an extravascular plug that is delivered with a specialized system. US24215232A1 describes an extravascular plug with an intravascular anchor set with a sheath with a detection port. US2005/0085855A1 describes an extravascular collagen plug, held in place with an intravascular anchor, and a device that locks over a piece of suture. U.S. Ser. No. 05/906,631 describes a plug made of hydrophilic material. U.S. Ser. No. 06/126,675 describes an intravascular anchor and a bioabsorble extravascular plug. U.S. Ser. No. 06/623,509 describes a bioabsorbable plug. U.S. Ser. No. 06/296,657 and U.S. Ser. No. 06/743,195 describe an inflatable balloon that puts pressure on the puncture site. U.S. Ser. No. 06/569,185 describes an injectable vascular plug. U.S. Ser. No. 06/663,655 describes a plug that screws in the puncture tract. US2004/0143290 A1 describes a combination of an intraluminal balloon and injectable sealant. Disadvantages to these methods are related to the high likelihood of thrombosis associated with the intravascular plug or anchor, and the presence of collagen or other bioabsorble materials which cause inflammation, activate the clotting cascade, and increase the likelihood of thrombosis, which, in an arterial system, is catastrophic. 
     Vascular patches have also been used for repairing blood vessels, but usually only for large areas of damage. U.S. Ser. No. 05/100,422 describes a vascular patch that is sutured to the external surface of the damaged blood vessel. U.S. Ser. No. 05/100,422 describes a vascular patch achieved by instilled adhesives and the device for doing such. These are generally impractical for catheter-based methods. U.S. Ser. No. 06/248,124 and U.S. Ser. No. 05/507,744 describe devices and methods that use electrocautery for sealing vascular punctures. This also requires a complicated device, and perforation and thrombosis are very real possibilities. 
     Vascular clips or staples delivered through a catheter device have also been proposed. These devices have penetrating members that bring the edges of the tissue together. U.S. Ser. No. 06/695,867 describes a clip or staple that is delivered by a specialized device. U.S. Ser. No. 06/749,622 describes a number of different clips with sharpened barbs or ends that include both intra- and extravascular portions, made of metal with memory characteristics. U.S. Ser. No. 05/861,005 describes an arterial staple that is delivered with a specialized device. U.S. Ser. No. 05/919,207 describes a stapling system based on long hooked wires that appose the surfaces, with a small staple gun to close the lesion. U.S. Ser. No. 06/022,372 describes a similar staple gun. U.S. Ser. No. 06/296,657, U.S. Ser. No. 06/663,655, and U.S. Ser. No. 06/749,621 describe a clip that is external to the vessel, but clips the two sides of the puncture together, and a device for achieving such. U.S. Pat. No. 5,782,861 and U.S. Pat. No. 5,964,782 describe clip devices composed of two or more prongs or hooks that, depending on the direction of the prongs, can clip together the puncture site from the intra- or extravascular position, through the use of a collar which forces the prongs together or other mechanisms. These clip devices are composed of thick semi-rigid material, and can be placed only with a specialized instruments, and because of the rigidity have great potential to injure or cut the blood vessel. Disadvantages of these clip devices in general include difficulty in retrieving the device if misplaced, excessive manipulation required, the thickness of the clip material which tends to cut or shear the blood vessel, the large forces that must be used to curve the staples and fix the clips, the increased possibility of tearing the blood vessel, and the general lack of control of the forces being applied to the blood vessel. 
     Accordingly, there is a need for methods and apparatuses that are suitable for closure of vascular punctures or other openings, and that do not suffer from the drawbacks of conventional approaches. 
     SUMMARY OF THE INVENTION 
     The present invention provides methods and apparatuses that are suitable for closure of vascular punctures or other openings, and that do not suffer from the drawbacks of conventional approaches. 
     An apparatus according to the present invention can comprise a base member, defining an opening of sufficient cross-section to allow passage of a sheath through the opening. This allows the apparatus to be conveyed to the tissue opening using a conventional sheath. A plurality of active members mount with the base member, where each active member mounts with the base member and is capable of first and second configurations. In the first configuration, the active members are spaced apart such that they can be delivered using a conventional sheath, and such that the spacing is sufficient to span a portion of the tissue opening to be closed. In the second configuration, the active members move toward each other (relative to the first configuration), urging tissue placed between the active members into apposition. In operation, the apparatus can be delivered using a conventional sheath, with the active members in the first configuration. At the site of the tissue opening, the active members can engage tissue around the opening, and then be placed in the second configuration; for example by moving the active members relative to the sheath such that the sheath no longer props the active members apart. The tissue engaged by the active members is urged into apposition by the motion of the active members assuming the second configuration, closing the tissue opening. 
     Apparatuses according to the present invention can provide a catheter-delivered clip comprising fine, strong, but flexible material that after delivery contracts on the wound edges of a blood vessel so that individual members of the clip extend beyond the catheter edges and/or puncture dimensions. As the catheter is withdrawn, the edges of the tissue opening (e.g., a puncture wound) go from inversion (facing intravascularly) to eversion (facing extravascularly) preparing the wound edges for delivery of the clip. The clip delivery sheath can be advanced over the catheter and guidewire until the site of puncture of the blood vessel is reached. The delivery sheath can be pushed against the exterior of the blood vessel so that the everted edges of the wound are just interior to the delivery sheath. Using an exterior pushing sheath which goes around the delivery sheath, the clip can be pushed off the delivery sheath. The feet of clip can have textured, hooked grasping devices on the ends of the members, which seize the exterior of the vessel wall and urge the edges together. 
     The use of a plurality of fine and flexible nature the members can close tissue opening with low shear force applied to the blood vessel. As the clip is pushed off the delivery sheath the feet contract together and bring the blood vessel puncture wound edges together. If there is no blood leakage through the closure and the device is properly positioned and stable, then first the catheter and then the guidewire can be removed and the retaining sutures or strings loop cut, resulting in complete and rapid closure, which can then heal. 
     Since the present invention brings the puncture edges together, there can be true blood vessel healing with little endothelial disruption, reducing the chances of thrombosis or intimal hyperplasia. The device can be supplied in different diameters (french) to accommodate different sizes of catheters and different sizes of puncture holes. The present invention can provide apparatuses that are both contractible and retrievable (e.g., because of misplacement). In addition, although the example embodiments described herein generally have linear members, these members need not be strictly linear, but can assume a number of complex geometrical shapes and structural patterns without departing from the scope of the present invention. 
     Devices according to the present invention can utilize a contractible material, for example with memory characteristics, that allow the members of the device to close spontaneously on a puncture wound of a blood vessel. Members of such devices can have textured gripping surfaces, tissue hooks, or penetrators, to seize the vessel wall and stabilize the device. Such devices can use the spontaneous closing characteristic to seize the edges of the puncture site, and close them, resulting in a complete vascular closure. Such devices can be kept in an expanded state (high energy state of a memory material) by a delivery sheath and assume its functional, closing form (low energy state of a memory material) when pushed off a delivery sheath. 
     The present invention also comprises methods for closing tissue openings, comprising everting the edges of a tissue opening, then placing a device according to the present invention near the everted edges. The device can then be pushed off its delivery sheath, allowing the active members of the device to engage the tissue and bring the edges of the opening into apposition. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
       The invention is explained by using embodiment examples and corresponding drawings, which are incorporated into and form part of the specification. 
         FIG. 1(   a,b ) is a schematic illustration of an external vascular closure clip according to the present invention. 
         FIG. 2(   a,b ) is a schematic illustration of an external vascular closure clip according to the present invention. 
         FIG. 3(   a,b ) is a schematic illustration of an external vascular closure clip according to the present invention. 
         FIG. 4(   a,b,c ) is a schematic illustration of an external vascular closure clip according to the present invention. 
         FIG. 5(   a, b, c ) is a schematic illustration of an external vascular closure clip according to the present invention. 
         FIG. 6(   a,b ) is a schematic illustration of a gripper and sheath according to the present invention. 
         FIG. 7(   a,b,c ) is a schematic illustration of eversion of the edges of a tissue opening using a device according to the present invention. 
         FIG. 8(   a,b,c,d,e,f,g ) is a schematic illustration of steps in a method of closing a tissue opening according to the present invention. 
         FIG. 9(   a,b,c,d,e,f ) is a schematic illustration of steps in a method of closing a tissue opening according to the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     The present invention provides apparatuses and methods for closing a vascular puncture wound or any tissue aperture, for example those resulting from the insertion of a vascular catheter or surgical instrument, trauma or disease. The present invention embraces both apparatuses and methods for closing tissue openings such as vascular punctures. Devices according to the present invention can be open on a delivery sheath and when pushed off the sheath assume a closed position. This behavior can be provided by forming at least a portion of the device of a memory metal or material. The stress free state corresponds to the state at which the apparatus has closed upon the everted edges of a puncture wound of a blood vessel, and the stressed state is when the device is open and seated on the delivery sheath. Example embodiments of tissue closure apposition devices according to the present invention are shown in  FIGS. 1 ,  2 ,  3 , and  4 . The descriptions may refer to “vessels” for convenience; the present invention is applicable to facilitate closure of various types of tissue openings. 
       FIG. 1(   a,b ) is a schematic illustration of an external vascular closure clip with multiple members.  FIG. 1   a  is a lateral view of a vascular closure clip in the open state (high energy state);  FIG. 1   b  is a lateral view of the same device in closed state (low energy state). The device comprises a base member  103 , shaped to allow passage of a delivery sheath (not shown) through the base member  103 . A plurality of active members  101  mount with the base member  103 . A portion  102  of each active member  101  has a tissue engagement feature; in the figure shown as serrations formed in the end of the member  101 . 
     In  FIG. 1   a , the active members  101  are spaced apart, allowing passage of a delivery sheath (not shown) between the active members  101 . As an example, if the device is placed on a delivery sheath, the delivery sheath can hold the active members  101  apart. In  FIG. 1   b , the active members  101  have moved toward each other, urging tissue engaged by the tissue engagement features into apposition. As an example, if the device is pushed past the edge of a delivery sheath, the delivery sheath will no longer hold the tissue engagement features  102  of the active members  101  apart, and the resiliency or memory characteristics of the active members  101  can urge the tissue engagement features 2 towards each other. A hook, open or closed loop  104  for string or suture or for retrieval can mount with the device, for example with the base member  103  as shown in the figure. 
     The figure presents for illustration purposes 4 active members; the device can comprise as few as two active members, and as many as are practical within applicable design considerations. The tissue engagement features, shown as serrated portions of the active members in the figure, can comprise textured portions or attachments, mating portions with apposing feet, penetrating devices, hooks, teeth, or other adaptations to allow firm grip of the tissue. The base member is shown in the figure as a complete circular or cylindrical band; the base member can also be an incomplete band to accommodate better grip of a delivery sheath, and can comprise memory materials to increase the grip on the delivery sheath, and to assume a lower profile when delivered. 
       FIG. 2(   a,b ) is a schematic illustration of an external vascular closure clip with two members.  FIG. 2   a  is a lateral view of a vascular closure clip with two members in the open state (high energy state).  FIG. 2   b  is a lateral view of the clip in the closed state (low energy state). The device comprises a base member  203 , shaped to allow passage of a delivery sheath (not shown) through the base member  203 . A plurality of active members  201  mount with the base member  203 . The active members  201  mount with tissue engagement members  205 . The figure shows two active members  201  per tissue engagement member  205 ; any number of active members  201  can mount with each tissue engagement member  205 . The tissue engagement members  205  comprise a tissue engagement feature  202 , shown in the figure as a serrated portion of a side of the tissue engagement member  205  facing other tissue engagement members  205 . A portion  202  of each active member  201  has a tissue engagement feature; in the figure shown as serrations formed in the end of the member  201 . 
     In  FIG. 2   a , the active members  201  are spaced apart, allowing passage of a delivery sheath (not shown) between the active members  201 . As an example, if the device is placed on a delivery sheath, the delivery sheath can hold the tissue engagement members  205  apart. In  FIG. 2   b , the active members  201  have flexed, moving the tissue engagement members  205  toward each other, urging tissue engaged by the tissue engagement features  202  into apposition. As an example, if the device is pushed past the edge of a delivery sheath, the delivery sheath will no longer hold the tissue engagement members  205  apart, and the resiliency or memory characteristics of the active members  201  can urge the tissue engagement members  205  towards each other. A hook, open or closed loop  204  for string or suture or for retrieval can mount with the device, for example with the base member  203  as shown in the figure. The tissue engagement members  205  allow gripping of the tissue along a greater surface than the example of  FIG. 1(   a,b ). The tissue engagement members  205  can comprise a resilient or memory material, allowing them to conform to the shape of a delivery sheath while mounted with such a sheath, then to conform to the shape of another tissue engagement member  205  when gripping tissue (e.g., in  FIG. 2   b  the tissue engagement members  205  present substantially straight and mutually parallel surfaces to each other). 
       FIG. 3(   a,b ) is a schematic illustration of an external vascular closure clip with penetrating grips.  FIG. 3   a  is a lateral view of a vascular closure clip with two active members  301  in the open state (high energy state).  FIG. 3   b  is a lateral view of the clip in the closed state (low energy state). The example of  FIG. 3  is similar to that of  FIG. 2 . In  FIG. 3 , however, the tissue engagement features  306 , 307  comprise penetrating members  307  mounted or formed with one tissue engagement member  305 , and corresponding depressions or openings  306  on a facing tissue engagement member  305 . A hook, open or closed loop  304  for string or suture or for retrieval can mount with the device, for example with the base member  303  as shown in the figure. 
       FIG. 4(   a,b,c ) is a schematic illustration of an external vascular closure clip with a low profile.  FIG. 4   a  is a lateral view of a vascular closure clip in the open state (high energy state).  FIG. 4   b  is a lateral view of the clip in the closed state (low energy state).  FIG. 4   c  is a top view of the clip in the closed state (low energy state). The arrangement and operation of the clip in the figure is similar to that described in relation to  FIG. 1 , except that the active members  401  (having tissue engagement features  402 ) are configured to have a lower profile when deployed. This can be useful when the height of the deployed clip relative to the tissue surface is of concern. The active members  401  can also be configured to be substantially planar with the base member  403  when deployed, and can also be inverted so that, when deployed, the base member  403  is closer to the tissue wall than are the active members  401 . A loop  404  for removal can mount with the base member  404 . The active members  401  can also comprise other shapes to achieve the desired low profile. As an example, the active members can comprise members extending from the base member toward the center of the base member roughly in the plane of the base member, analogous to an iris diaphragm. As another example, the active members can be arranged like spokes, with the base member as the rim, where the spokes define an inner cross-section that is held open before deployment, and that is reduced by action of the spokes when the device is deployed. As another example, the active members can comprise members of variable length, mounted with the base member and extending roughly radially inward from the base member. The active members can be constrained to a shortened length before deployment, and allowed to lengthen (reducing the area between the active members) when deployed. 
       FIG. 5(   a,b,c ) is a schematic illustration of an external vascular closure clip with penetrating grips.  FIG. 5   a  is a lateral view of a vascular closure clip device in the open state (high energy state).  FIG. 5   b  is a lateral view of the clip in the closed state (low energy state). The structure and operation of the device in  FIG. 5  is similar to that described in relation to  FIG. 1 , with a loop  504 , extending from a base member  503 , which can facilitate removal of the device. In the device of  FIG. 5 , however, then tissue engagement features  502  comprise portions of the active members  501  adapted to penetrate the tissue, in the figure sharpened ends of the active members. Penetration of the tissue by the ends of the active members  502  can facilitate more certain anchoring of the clip when deployed. The active members can also comprise more complicated shapes and relationships among the active members, e.g., spirals, cross-overs, barbs, and complete or incomplete twists and turns, all which can be determined by the characteristics of the material and the desired tissue binding forces. 
     For simplicity of illustration, the previous embodiments were depicted with wire-like active members. The active members can comprise other shapes and materials. As an example, active members can be made with polymers, covered with polymers, and comprise drug-eluting material. The active members or base member, or both, can be covered with fabric or backing or other material, including bioreabsorbable material, to further plug the puncture tract. The active members can comprise loops of wire, filaments, struts, beams, patterns, woven elements, continuous or non-continuous materials, or other geometric structures. 
     Any part of an apparatus according to the present invention can be made from any of a number of suitable materials, or combinations thereof. In some applications, it can be desirable for members to be of radioopaque materials or be coated to be made radioopaque. Members can be made from bioabsorbable polymers or compounds, non-absorbable alloys and compounds including stainless steel, MP35, Nitinol, Nickel-Titanium alloy, Kevlar, nylon polyester acrylic, gold, platinum, tantalum, niobium, molybdenum, rhodium, palladium silver, hafnium, tungsten, iridium. Materials with memory can be useful, where the memory property can provide force for activation of the active members from the open to the closed state. Members can be made in the form of wires, fibers, filaments, small beams, and other extruded, woven, or formed shapes. Examples of suitable materials include piano wire, super elastic memory wire, chromium allows, alloys of titanium and nickel, and other elastic memory materials. A suitable fabric or coating can be made from a number of suitable materials; in some applications it can be desirable to use flexible polymeric materials with elastomeric properties including polyurethane, polyethylene, polyestenurethane, polyimide, olyethreimide, polycarbonate, polysiloxane, polyvinyls, hydroxyethylmethacrylate, related polymers, co-polymers of these or other polymers, or drug-embedded or drug-eluting polymers to prevent coagulation or intimal hyperplasia (such as Taxol), which can be made radioopaque by markers to addition of appropriate radiopaque materials. 
     Devices according to the present invention can be placed on everted tissue edges (i.e., the edges of the opening are turned towards the device). Tissue edge eversion can be accomplished with a gripper or everter device, or by pulling back a sheath.  FIG. 6(   a,b ) is a schematic illustration of a gripper and sheath, shown in section to illustrate gripper tines disposed within the sheath  603 . Gripper tines  602  (two in the figure although more or fewer can be used) are disposed within a sheath  603  in  FIG. 6   a . The sheath  603  constrains the gripper tines  602  to fit within the walls of the sheath  603 . In  FIG. 6   b , the gripper tines  602  have moved past the end of the sheath  603 . Absent the constraining influence of the sheath  603 , the gripper tines  602  have curved outwards from the sheath and upwards along the direction of the sheath. The gripper tines can grip the edges of a tissue opening, and evert them when the gripper tines or the corresponding sheath is pulled away from the tissue. 
       FIG. 7(   a,b,c ) is a schematic illustration of eversion of the edges of a tissue opening using a device such as that described in relation to  FIG. 6 .  FIG. 7   a  shows the device with the gripper tines  702  constrained in a sheath  703 . A guidewire  704  passes through the sheath  703 . The sheath  703  is resident in the tissue opening, passing through the proximal vessel wall  706  but not reaching the distal vessel wall  705 .  FIG. 7   b  shows the device after the gripper tines  702  have been extended past the end of the sheath  703 . The gripper tines  702 , have curved away from the sheath  703  and back along the direction of the sheath  703 , penetrating the proximal vessel wall  706 . Traction applied to the gripper tines  702  and sheath  703  everts the edges of the opening, as shown in  FIG. 7   c . The edges are held by the gripper tines  702  so that the proximal vessel wall  706  is pulled when the gripper tines  702  and sheath  703  are pulled. The everted edges of the tissue opening are now ready for deployment of a clip like those described herein. 
       FIG. 8(   a,b,c,d,e,f,g ) is a schematic illustration of steps in a method of closing a tissue opening according to the present invention. In  FIG. 8   a , a gripper sheath  801 , for example a gripper sheath like that described in relation to  FIG. 7 , is present within an opening in tissue, near a proximal wall  806  and edges  805  of an opening therethrough, but not near a distal wall  807 . The gripper sheath  801  constrain gripper tines  802  disposed within the gripper sheath  801 . In  FIG. 8   b , the gripper tines  802  have been extended past the end of the gripper sheath  801 , curving back and engaging the edges  805  of the tissue opening. In  FIG. 8   c , the gripper sheath  801  has been pulled away from the tissue. The edges  805  of the opening, held by the gripper tines  802 , have been everted by the motion of the gripper sheath  801 . The gripper tines can reside within sublumens within or on the sheath, or a single shared lumen in the sheath. The number of gripper tines can be 2 or greater, and they can be directed away from the lumen or cross over each other. They can penetrate the blood vessel wall, but need not fully penetrate the vessel, instead simply gripping the vessel wall so it cab be everted. The tines can be extended by pushing or by a specialized instrument that provides suitable extension such as a gun-like or syringe-like plunger configuration. 
     In  FIG. 8   d  two additional sheaths are shown. A delivery sheath  803  has mounted with it a closure device  804  such as those described herein. A pushing sheath  808  is placed in relationship with the delivery sheath  803  such that the pushing sheath  808  can slide down the delivery sheath  803  and apply force to the device  804 . If  FIG. 8   e  the pushing sheath  808  has been pushed down the delivery sheath  803  a sufficient distance to force the device  804  past the end of the delivery sheath  803 . As described previously in relation to device embodiments, the device, when free of the constraining influence of the delivery sheath  803 , assumes a closed state wherein the device  804  urges the edges  805  of the opening into apposition. In  FIG. 8   f , the sheaths have been pulled away from the opening, leaving the device  804  engaged with the tissue and the edges of the opening held in apposition by the device  804 . The tissue can be inspected at this stage to assess proper placement and operation of the device. If the opening has been appropriately closed, then the sheaths and guidewire can be removed, leaving the device  804  in place to hold the opening closed, as shown in  FIG. 8   g.    
       FIG. 9(   a,b,c,d,e,f ) is a schematic illustration of steps in a method of closing a tissue opening according to the present invention. In  FIG. 9   a , an operative catheter or sheath  901  is present within an opening in tissue, in contact with edges  905  of the opening. A device  904  such as those described herein mounts with a delivery sheath  903 . In  FIG. 9   b , the operative catheter or sheath  901  has been pulled away from the tissue sufficient to evert the edges  905  of the opening. In  FIG. 9   c , a pushing sheath  908  has been introduced outside the delivery sheath  903 , configure to transmit force to the device  904 . 
     In  FIG. 9   d , the pushing sheath  908  has been used to push the device  904  past the end of the delivery sheath  903 , but not yet past the end of the operative catheter or sheath  901 . As described herein, the device can assume a closed state once free from the constraint of the delivery sheath  903 . In the closed state, the device brings the edges  905  of the opening into apposition. In  FIG. 9   d , the device can be less than fully closed, since the operative catheter or sheath  901  is still in position to prevent full closure. In  FIG. 9   e , the operative catheter or sheath  901  has also been withdrawn relative to the device  904  and pushing sheath  908 , allowing the device  904  to assume the closed state, bringing the edges  905  of the tissue opening into apposition. The tissue can be inspected at this stage to assess proper placement and operation of the device. If the opening has been appropriately closed, then the sheaths and guidewire  909  can be removed, leaving the device  904  in place to hold the opening closed, as shown in  FIG. 9   f.    
     The particular sizes and equipment discussed above are cited merely to illustrate particular embodiments of the invention. It is contemplated that the use of the invention may involve components having different sizes and characteristics. It is intended that the scope of the invention be defined by the claims appended hereto.