Patent Publication Number: US-2022225990-A1

Title: Devices for approximating tissue and related methods of use

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application is related to, and claims priority from, U.S. Provisional Patent Application Ser. No. 61/272,457 filed on Sep. 25, 2009 which is incorporated herein by reference in its entirety. 
    
    
     FIELD OF THE INVENTION 
     Embodiments of the present invention relate to tissue approximation clips used during surgery. In particular, embodiments of the present invention relate to clips that may be used to bring tissue edges proximate to one another to close apertures created during surgery. 
     BACKGROUND OF THE INVENTION 
     During recent years, a major drive in surgery has been the development and application of minimally invasive approaches to traditional operations. In general surgery, an emphasis has been on laparoscopic techniques, which can now be applied to a majority of intra-abdominal procedures. The resulting reduction in trauma to the abdominal wall has a positive impact on patients undergoing abdominal operations. 
     More recently, there has been interest in less traumatic transluminal endoscopic surgical procedures. In transluminal endoscopic surgery, an endoscope is used to deliberately breach (puncture) the wall of the stomach or other organ to work within a body cavity such as the peritoneal cavity. Single point access surgery, is an advanced minimally invasive surgical procedure in which the surgeon operates almost exclusively through a single entry point, such as the patient&#39;s navel. In a transluminal endoscopic surgical procedure, a flexible endoscope (along with the required surgical tools) is inserted into the stomach, for example, through a natural anatomic opening. Once the endoscope reaches the access site in the stomach or other organ, the wall of the organ is punctured and the endoscope advanced into the body cavity where the remotely controlled surgical tools can be used to perform delicate surgical procedures. When the surgical procedure is completed, the endoscope and the tools are withdrawn through the aperture in the organ wall and the aperture is closed. 
     Although minimally invasive surgeries have tremendous potential in reducing trauma associated with surgical procedures, several important developments should be pursued before these procedures can be widely employed. One such development is a safe and effective method of approximating two tissue edges in the body cavity so that they can be stapled or otherwise joined together. Existing tissue approximation techniques only enable joining of two tissue edges which are already in close proximity to one another. There is often a need to bring one tissue edge from a first location to the location of a second tissue edge in order to join them, and thereby, initiate healing. 
     SUMMARY OF THE INVENTION 
     An embodiment of the invention may include a device to approximate multiple tissue edges. The device may include a plurality of jaws each having a first end and a second end coupled at the first ends. The device may also include a fixed element located between the jaws. A jaw may be independently moved with respect to the fixed element from an open configuration to a closed configuration. The open configuration may be a configuration where a second end of a jaw is located away from a fixed element and the closed configuration may be a configuration where a second end of a jaw mates with a fixed element to grasp a tissue edge between a jaw and a fixed element. 
     Various embodiments of the invention may include one or more of the following aspects: one end of a fixed element may be coupled to a jaw at the first end; a first end may be coupled to a distal end of an elongate member, and a proximal end of an elongate member may be coupled to an actuation device, an actuation device may be configured to move a jaw with respect to a fixed element, and an elongate member may be configured to pass through a lumen of an endoscope; a fixed element may include barbs; and a barb may be configured to pierce a tissue edge between a jaw and a fixed element. 
     An embodiment of the invention may also include a device to approximate multiple tissue edges. The device may include a plurality of jaws each including a first end and a second end. The jaws may be coupled to each other at their first ends and configured to transform from an open configuration to a closed configuration. The open configuration may be a configuration where a second end of a jaw is located away from a second end of another jaw. The closed configuration may be a configuration where a second end of a jaw is proximate a second end of another jaw. The device may also include one or more tools configured to pass between the jaws. A tool may be configured to move relative to the jaws and grasp a tissue edge between the jaws. 
     Various embodiments of the invention may also include one or more of the following aspects: a first end of a jaw may be coupled to a distal end of an elongate member, and an elongate member may be configured to pass through a lumen of an endoscope; a first end may include a hole and an elongate member may extend through the hole; a tool may be coupled to a distal end of an elongate section, a proximal end of an elongate section may be coupled to an actuation device configured to be located external to the body, and an actuation device may be configured to control a tool to grasp a tissue edge. 
     An embodiment of the invention may also include a device to approximate tissue edges. The device may include a plurality of jaws coupled to each other at a first end, and a midsection located between the jaws. The midsection may include a plurality of forks coupled together. A fork may be configured to move to mate with a jaw and grasp a tissue edge between the fork and a jaw. 
     Various embodiments of the invention may also include one or more of the following aspects: a midsection coupled to a distal end of an elongate member, and a proximal end of an elongate member coupled to an actuation device, an actuation device may be configured to move a fork; a distal end of an elongate member may include a groove, and a first end of a jaw may be located proximate a groove; and the jaws may be joined at a first end, a first end may include a hole through which a midsection passes. 
     An embodiment of the invention may also include a device to approximate tissue edges. The device may include a first jaw including a proximal end and a distal end, and a second jaw including a proximal end and a distal end. A first jaw and a second jaw may be configured to transform from an open configuration to a closed configuration. The open configuration may be a configuration where distal ends of the jaws are located away from each other, and the closed configuration may be a configuration where the distal ends of the jaws are located proximate to each other. The device may also include a barb including a first end and a second end. The first end may be coupled to a jaw. The device may also include a feature on a jaw, the feature may be configured to receive a second end of a barb when the jaws are in the closed configuration. 
     Various embodiments of the invention may also include one or more of the following aspects: a first jaw may move relative to a second jaw; a feature may include a hole; a jaw may include elements configured to increase the compliance of a jaw; a barb may be configured to transform from a first configuration to a second configuration, the first configuration may be a restricted configuration where a second end of a barb is proximate a jaw, and the second configuration may be a deployed configuration where a second end of a barb is distal to a first jaw; a second end of a barb may include a sharp tip; a barb may include a plurality of spikes protruding from a surface of a barb; first and second jaws may be coupled to an end of an elongate member, the elongate member may be configured to pass through a lumen of an endoscope. 
     An embodiment of the invention may also include a method of approximating tissue edges. The method may include delivering a clip to a location of a tissue edge. The clip may include a plurality of jaws and a fixed element, wherein a jaw may be moved from an open configuration to a closed configuration. The method may also include grasping a tissue edge between a jaw and a fixed element, and moving a clip along with a grasped tissue edge to a location proximate to a second tissue edge. The method may further include grasping a tissue edge between a second jaw and a fixed element, and releasing a clip with a tissue edge grasped between the jaws. 
     Various embodiments of the invention may also include one or more of the following aspects: a fixed element may be located between the jaws; a jaw may be independently moved with respect to a fixed element; a closed configuration of a jaw may be a configuration where a jaw mates with a fixed element, and an open configuration may be configuration where a jaw may be disposed away from a fixed element; delivering a clip may include delivering a clip through a lumen of a device extending into a body; extending a clip outside a lumen may transform a jaw into an open configuration and retracting a clip into a lumen may transform a jaw into a closed configuration; the method may further include retracting a clip into a lumen to transform a jaw to a closed configuration; grasping a tissue edge between a jaw and a fixed element; and grasping another tissue edge between a jaw and a fixed element; a fixed element may include a barb configured to pierce a tissue edge. 
     An embodiment of the invention may also include another method of approximating tissue edges. The method may include delivering a clip including multiple jaws to a location of the tissue edges, and delivering a first tool to a location of the tissue edges. The method may also include grasping a tissue edge using a first tool, and retracting a first tool with a grasped tissue edge to a location in between the jaws, and delivering a second tool to a location of the tissue edges. The method may further include grasping a second tissue edge using a second tool, and retracting the second tool with a grasped tissue edge to a location in between the jaws to approximate the tissue edges. 
     Various embodiments of the invention may also include one or more of the following aspects: a jaw may include a proximal end and a distal end and may be configured to transform from an open configuration to a closed configuration, the open configuration may be a configuration where a distal end of the jaws are located away from each other, and the closed configuration may be a configuration where a distal end of the jaws are proximate to each other; delivering a clip may include delivering a clip through a lumen of a device extending into a body; the lumen may include one of a lumen of a catheter or a working lumen of an endoscope; extending a clip outside the lumen may transform a jaw into an open configuration, and retracting a clip into a lumen may transform the clip into a closed configuration; the method may further include extending a clip outside a lumen to transform a jaw into an open configuration, and retracting a clip into a lumen to transform a clip to a closed configuration and grasp a tissue edge between the multiple jaws; the method may further include releasing a tissue edge from a first tool and a tissue edge from a second tool, and releasing a clip with the clip grasping the tissue edges; piercing the grasped tissue edges with a barb to join the tissue edges together; releasing a tissue edge from a first tool and a second tissue edge from a second tool, and releasing a barb with a barb piercing a tissue edge. 
     An embodiment of the invention may also include another method of approximating tissue edges. The method may include delivering a clip to a location of the tissue edges, the clip may include jaws coupled together, at least one jaw movable relative to another other jaw from an open configuration to a closed configuration, and a barb coupled to a jaw. The method may also include transforming a movable jaw to a closed configuration to grasp a tissue edge between the jaws, and piercing the tissue edge with a barb. The method may further include moving a clip along with a grasped tissue edge to a location proximate to another tissue edge, and transforming a movable jaw with the grasped tissue edge to an open configuration. The method may also include transforming a movable jaw to a closed configuration to grasp a tissue edge between the jaws, the tissue edge may be pierced by a barb. 
     Various embodiments of the invention may also include one or more of the following aspects: a barb may pierce a tissue edge while a movable jaw may transform to a closed configuration to grasp a tissue edge; the closed configuration may be a configuration where a distal end of each of the jaws is proximate to each other, and the open configuration may be a configuration where a distal end of each of the jaws is located away from each other; a barb may include a first end and a second end, the first end may be coupled to a jaw and a second end may form a sharp point; a second end of a barb may be proximate a first jaw; the method may further include moving a barb to a deployed orientation, wherein a second end of a barb may be positioned to pierce a tissue edge after transforming the movable jaw to a closed configuration to grasp a tissue edge; the method may also include compliance features on a jaw; a barb may include a plurality of spikes protruding from a surface of a barb; releasing a clip with a clip grasping the tissue edges; uncoupling a barb from a clip with the barb piercing the tissue edges; delivering a clip includes delivering a clip through a lumen of a device extending into the body, the device may include one of a catheter or an endoscope. 
     An embodiment of the invention may also include another method of approximating tissue edges. The method may include delivering a clip mounted on an elongate member to a location of a tissue edge, the elongate member may include multiple forks at a distal end, and a clip including multiple jaws located about the forks, wherein a fork may be moved between a closed configuration and an open configuration. The method may also include moving a fork to an open configuration to grasp a tissue edge between a fork and a jaw, and moving a clip along with a grasped tissue edge to a location proximate to a tissue edge. The method may also include moving a fork to an open configuration to grasp a tissue edge between a fork and a jaw, and releasing a clip with a clip grasping a tissue edge. 
     Various embodiments of the invention may also include one or more of the following aspects: delivering a clip may include delivering a clip through a lumen of a device extending into a body; extending a clip outside a lumen may transform a jaw into an open configuration and retracting a clip into a lumen may transform a jaw into a closed configuration, the open configuration may be a configuration where a distal end of the jaws is located away from each other, and the closed configuration may be a configuration where a distal end of the jaws is located proximate to each other; extending a clip outside a lumen to transform a jaw into an open configuration, and retracting a clip into a lumen to transform a jaw to a closed configuration and grasp the tissue edges between the jaws and the forks; retracting forks from between the jaws in the closed configuration; delivering a clip includes locating a clip on a groove of an elongate member, the groove may be located proximate a distal end of an elongate member; locating a second clip on a groove after releasing a clip; a fork may be independently moved with respect to another fork between a closed configuration and an open configuration; and a plurality of clips may be mounted on an elongate member. 
     An embodiment of the invention may also include another method of approximating tissue edges. The method may include delivering a clip including multiple jaws to location of tissue edges, wherein the jaws are configured to transform between an open configuration and a closed configuration, delivering a capture tool into the body, and snagging a tissue edge using a capture tool. The method may also include retracting a capture tool to drag a tissue edge between the jaws, transforming the jaws to a closed configuration to grasp a tissue edges between the jaws, and releasing a clip with a clip grasping the tissue edges. 
     Various embodiments of the invention may also include one or more of the following aspects: delivering a clip includes delivering a clip through a lumen of a device extending into a body; extending a clip outside a lumen transforms the jaws into an open configuration, and retracting the clip into a lumen transforms the jaws into a closed configuration, the open configuration may be a configuration where a distal end of the jaws is located away from each other, and the closed configuration may be a configuration where a distal end of the jaws are located proximate to each other; extending a clip outside a lumen to transform the jaws into an open configuration, and retracting a clip into a lumen to transform the jaws to a closed configuration; delivering a capture tool into the body may include delivering a first capture tool into the body in between the jaws, and delivering a second capture tool into the body in between the jaws; snagging tissue edges may include snagging a tissue edge using a first capture tool, and snagging a tissue edge using a second capture tool; retracting a capture tool may include retracting a capture tool to drag a tissue edge to a location between the jaws, and retracting a capture tool to drag a second tissue edge to a location between the jaws; delivering a clip includes delivering a clip mounted on an elongate member into a body, and releasing a clip includes sliding a clip off an elongate member. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description, serve to explain the principles of the invention. 
         FIG. 1  is a schematic view of an endoscope performing an exemplary endoscopic surgical procedure. 
         FIGS. 2A and 2B  are schematic views of exemplary clips for closing an aperture created during an endoscopic surgical procedure. 
         FIGS. 3A-3H  are illustrations of an exemplary method of using a clip. 
         FIG. 4  is a schematic view of another embodiment of a clip. 
         FIGS. 5A-5D  are illustrations of an exemplary method of using a clip. 
         FIG. 6  is a schematic view of another embodiment of a clip. 
         FIGS. 7A-7E  are illustrations of an exemplary method of using a clip. 
         FIGS. 8A and 8B  are illustrations of another embodiment of a clip and a method of using a clip. 
         FIGS. 9A-9D  are illustrations of another embodiment of a clip and a method of using a clip. 
         FIG. 10  is a schematic view of another embodiment of a clip. 
         FIGS. 11A-11E  are illustrations of an exemplary method of using a clip. 
         FIGS. 12A-12E  are illustrations of another embodiment of a clip and a method of using a clip. 
         FIGS. 13A-13E  are illustrations of another embodiment of a clip and a method of using a clip. 
         FIGS. 14A-14F  are illustrations of another embodiment of a clip and a method of using a clip. 
     
    
    
     DESCRIPTION OF THE EMBODIMENTS 
     Reference will now be made in detail to exemplary embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. Even so, the invention is not limited to the specific embodiments and drawings listed herein. 
       FIG. 1  depicts an exemplary endoscope  10  performing an exemplary endoscopic surgery. Non-limiting examples of the endoscopic surgery may include choecsyectomies, gastrojejunostomies, stomach resections, polypectomies, vasectomies, tubal ligations, etc. In one embodiment, an endoscope  10 , or other suitable device such as a guide tube or a catheter, may be inserted into the stomach  5  through the esophagus. Endoscope  10  may make an aperture  80  on organ wall  70 , pass through the aperture  80 , and operate at a work site. The work site could include, for instance, part of the small intestine  50 . It should be emphasized that the illustrated application of the endoscope  10  in  FIG. 1  is exemplary only, and that the inventions of the current disclosure may be applied to any surgical application or medical procedure known in the art. 
     Endoscope  10  may include an elongate member  15  extending between a proximal end  60  and a distal end  90 . In the configuration depicted in  FIG. 1 , the proximal end  60  may include the end of endoscope  10  external to the body and the distal end  90  may include the end of endoscope  10  internal to the body. A plurality of lumens  20  may run longitudinally through endoscope  10 . The lumens  20  may extend between the proximal end  60  external to the body and the distal end  90  internal to the body. In some embodiments, the longitudinal axes of the lumens may be substantially parallel to the longitudinal axes of the endoscope  10 . 
     The lumens  20  may provide access to devices and facilities that may aid in performing a diagnostic or therapeutic task inside the body. In general, the lumens may be of any shape or geometry. In some embodiments, some or all lumens may be lined with a polymeric or another layer or coating to facilitate use. These lumens  20  may include one or more of, among others, an aspiration lumen, an irrigation lumen, an illumination lumen, a viewing lumen, and working lumens. The illumination lumen may include devices at the distal end configured to illuminate the work site. These devices may include, among others, bulbs, LED&#39;s, fiber optic cables and light guides. The viewing lumen may include devices (such as a camera) at the distal end  90 , configured to deliver an image of the work site external to the body. In some embodiments the camera may be a digital camera, such as a CCD or a CMOS camera. The illumination and the viewing lumens may also include cables that may run from the distal end  90  to the proximal end  60 . 
     The irrigation lumen may be configured to facilitate fluid flow from the proximal end  60  to the distal end  90 . In some embodiments, the proximal end  60  of the irrigation lumen may be attached to a source of fluid, and the distal end  90  may be attached to a nozzle to alter fluid flow. The aspiration lumen may be configured to facilitate suction and/or fluid flow through it. In some embodiments, fluid may flow from the proximal end  60  to the work site through the irrigation lumen. The fluid may then be removed from the work site through the aspiration lumen. In some embodiments, the aspiration lumen may also be configured to remove biological material along with fluid from the work site. For instance, a tissue sample along with fluid (delivered to the work site via the irrigation lumen) may be extracted out of the body through the aspiration lumen. 
     The working lumen may include a hollow cavity configured to deliver an endoscopic instrument  30  to the work site. The endoscopic instrument  30  may include a surgical tool configured to operate at the work site while being remotely controlled from outside the body. The surgical tool may be configured as an end effector  32  that may be attached at the distal end of the endoscopic instrument  30 . In general, the working lumen may have any suitable shape, size, and configuration. In some embodiments, the working lumen may have a substantially circular cross-section, while in other embodiments, the shape of the working lumen may be configured to pass the end effector  32  of the endoscopic instrument  30  through it. Some embodiments of the endoscope may include a plurality of working lumens to deliver multiple surgical tools to the work site. 
     In addition to the end effector  32 , an endoscopic instrument  30  may also include a mechanism to operate the end effector  32  from outside the body. This mechanism may include linkage that connects the end effector  32  to an actuation device (not shown) at the proximal end. This linkage may operate the end effector  32  in response to actuation by the actuation device. For example, in some embodiments, the end effector  32  may include forceps with a pair of jaws rotably coupled to each other. The linkage, in this embodiment, may include a pair of cables, each coupled to a jaw of the forceps at the distal end and to the actuation device at the proximal end. Actuation of the actuation device may move one of the cables relative to the other, causing the jaws of the forceps to open and close. 
     The end effector  32  may include any medical instrument that may be used in conjunction with the endoscope  10 . In some embodiments, the end effector  32  may be a purely mechanical medical instrument (for example, biopsy forceps, baskets, graspers, snares, surgical knifes, needles, suturing instruments, etc.), while in others, the end effector  32  may also include devices with parts driven by an electric current (for instance, electric motors, heating elements for cutting or cauterizing, hemostasis devices, radio frequency ablation devices, etc.). The end effector  32  may also include a surgical instrument, such as a trocar, used to puncture an internal surface of the body. 
     In the exemplary transluminal endoscopic surgery illustrated in  FIG. 1 , the endoscope  10  may be inserted into the body through a natural anatomic opening (such as, mouth, anus, and vagina, etc.) or through the body percutaneously. When the distal end  90  of the endoscope  10  is proximate to an internal surface (such as, organ wall  70 ), an endoscopic instrument  30 , for example, an end effector suitable for puncturing organ wall  70 , may be delivered to the distal end  90  of the endoscope  10  via the working lumen. The end effector may be used to puncture the organ wall  70 . Puncturing the organ wall  70  may create cut multiple tissue edges. These tissue edges may include a first tissue edge  70   a  and a second tissue edge  70   b . Once the organ wall  70  is punctured, the endoscopic tool  30  with the end effector  32  may be withdrawn from the working lumen, and the endoscope  10  inserted into the abdominal cavity through the aperture  80 . When the distal end  90  of the endoscope  10  is positioned at the desired work site, for instance, the intestine  50 , an endoscopic instrument  30  with an end effector  32  configured to perform a desired task may be delivered to the work site through the working lumen. 
     The desired operations may be performed at the work site using an end effector  32 . If more than one tool is required to complete the desired task, other desired end effectors  32  may also be delivered to the work site. After completion of the desired operations, the endoscope  10  and tools may be retracted from the abdominal cavity through aperture  80 . Aperture  80  may now be closed by joining the separated tissue edges (for example, first tissue edge  70   a  and second tissue edge  70   b ) to initiate the healing process. To close aperture  80 , two or more tissue edges spatially dislocated from each other may have to repositioned close to each other (referred to herein as “approximated”) before they can be joined together. A tissue approximation clip according to embodiments of the present disclosure may now be delivered to the access site  55  or aperture via the working lumen. The approximation clip may be configured to grasp tissue edges at different locations at the access site  55 , bring them in close proximity to each other, and join the tissue pieces together. 
     The tissue approximation clips of the present disclosure may be made of any suitable biocompatible material. In general, a clip may be comprised of a material having any type of constitutive behavior, such as, a material exhibiting a behavior which is elastic, plastic, elastic-perfectly plastic, hyper-elastic, etc. In some embodiments, a bioabsorbable material may be included. It is also contemplated, that in some embodiments, a clip may be comprised of multiple components made of multiple materials. In some embodiments, a clip may comprise a shape memory alloy (SMA). Non-limiting examples of SMA&#39;s included in the clip include alloys of titanium-palladium-nickel, nickel-titanium-copper, gold-cadmium, iron-zinc-copper-aluminum, titanium-niobium-aluminum, iron-manganese-silicon, nickel-titanium, nickel-iron-zinc-aluminum, copper-aluminum-iron, titanium-niobium, etc. In some embodiments, a clip may comprise or consist of nitinol. 
     In general, clips of the present disclosure may be made by any process known in the art. In some embodiments, arms or jaws of the clip may be formed by a bending operation of material, and holes or cavities through the clip may be formed by a machining or laser drilling operation. In some embodiments, the clip may be subjected to heat treatment or other microstructure modification metallurgical operations during or after the fabrication process. In embodiments, where the clip may comprise a shape memory alloy, the material of the clip or the manufactured clip may be subjected to metallurgical treatments. These metallurgical operations may enable the clip to transform from a first configuration to second configuration by the application of heat or other stimuli. The first configuration may correspond to a martensitic phase and the second configuration may correspond to an austenitic phase of a shape memory alloy. Several embodiments of clips of the present disclosure and their method of operation will now be described in the following paragraphs. 
       FIG. 2A  illustrates an embodiment of the tissue approximation clip  40  that may be delivered to aperture  80 . Clip  40  may comprise a unitary construction, and may resemble a strip of material folded along a plane  54 , at an angle to, and passing through a center of the strip. Clip  40  may have two jaws, a second jaw  42   a  and a first jaw  42   b , joined by a midsection  43 . Clip  40  may further include a through-hole  46  therethrough. An inside surface of the two jaws may have an irregular or corrugated surface such as teeth  45 . Although the surface corrugation of clip  40  is depicted as teeth  45 , any kind of surface configurations may also be used. In some embodiments, the second jaw  42   a  and the first jaw  42   b  may be symmetric about plane  54  which may pass through a center of through-hole  46 . However, it is contemplated that, in some embodiments, the two jaws may not be symmetric. The through-hole  46  may have any shape. In some embodiments, the through-hole  46  may have a circular shape. 
     Although clip  40  is depicted as having two jaws (second jaw  42   a  and first jaw  42   b ) and an unvarying cross-section along a thickness direction, it is contemplated that clip  40  may have other configurations. For instance, in the embodiment of the clip  40   a  depicted in  FIG. 2B , clip  40   a  may resemble the shape of a tulip having at least three jaws, a second jaw  42   a , a first jaw  42   b , and a third jaw  42   c . The jaws may be substantially shaped like petals of the tulip. Other embodiments of the clip  40   a  may have a different number of jaws. As in the embodiment illustrated in  FIG. 2A , the jaws of clip  40   a  may be joined by a midsection  43   a  with a through-hole  46   a  centrally located therein. An axis  54   a  may pass through a center of the through-hole  46   a , and an inside surface of the three jaws may have a corrugated surface or teeth  45   a.    
       FIGS. 3A-H  illustrate an exemplary method of using a clip  40  to approximate tissue edges and join them. One or more clips  40  may be loaded on a push-rod  22  and delivered to the access site  55  though a tubular catheter  35 . The clips  40  may be constrained to be in a closed configuration while inside the catheter  35 . At access site  55 , clip  40  still mounted on push-rod  22  may be extended from within the catheter  35 . When clip  40  emerges from within the catheter  35 , a constraint which holds the clip in a closed configuration may be released, and the clip may expand to an open configuration. It is also contemplated that in some embodiments, a constrain may force the clip to an open configuration when clip  40  emerges from catheter  35 . The access site  55  may have one or more tissue edges, a first tissue edge  70   a  and a second tissue edge  70   b , created while traversing through organ wall  70 . The first tissue edge  70   a  may be grasped between one jaw and the push-rod  22  and dragged to the location of the second tissue edge  70   b . The second tissue edge  70   b  may then be grasped between another jaw and the push-rod  22 . Push-rod  22  may then be pulled out from between clip  40  and retracted into catheter  35 , releasing clip  40  with the tissue edges clutched between its jaws. The released clip  40  may now approximate first tissue edge  70   a  and second tissue edge  70   b . Each step of some embodiments of this method of operating clip  40  will now be described in greater detail. 
       FIGS. 3A and 3B  illustrate mounting a clip  40  on push-rod  22 . Push-rod  22  may be an elongate member having a groove  28  near its distal end. Past groove  28 , the push-rod may include a hinge with two forks, a second fork  24   a  and a first fork  24   b . The two forks may form the distal most part of push-rod  22 . Hinge  26  may allow each fork to open independent of the other. In some embodiments, opening of the forks may be a purely mechanical operation, while in other embodiments, energy such as heat and/or electricity may be used alone or in combination with mechanical energy to open the forks. While opening, second fork  24   a  and first fork  24   b  may rotate about the hinge  26 . While closing, the forks may rotate in the opposite manner. Although the forks are described as rotating about hinge  26  while opening and closing, it is also contemplated that in some embodiments, the two forks may move in another manner with respect to each other while opening and closing. Opening and closing of the forks may be controlled by an actuation mechanism at the proximal end of push-rod  22 . This actuation mechanism may include linkages that connect the forks to the actuation mechanism. These linkages may open and close the forks in response to activation by the actuation device. In some embodiments, linkages may include cables coupled to each fork. In these embodiments, pulling the cable connected to a fork may open the fork. In other embodiments, a push rod may push the forks open. In some embodiments, the forks may be biased to remain in a closed configuration with a spring. In these embodiments, pulling the cable may open the forks, and releasing the cable may close the forks. 
     The distal end of push-rod  22  may be inserted into through-hole  46  to load one or more clips  40  on the push-rod, such that the jaws of the loaded clips face the forks. In some embodiments, the diameter of through-hole  46  and push-rod  22  may be such that frictional resistance between the mating surfaces of the clips and the push-rod retains clips  40  on the surface of push-rod  22 . The clip closest to the two forks may be located on push-rod  22  such that through-hole  46  of the clip may be positioned on groove  26 . While clip  40  is in this position, opening a fork of the push-rod may rotate the fork until it rests on teeth  45  of a jaw of clip  40 . For instance, when clip  40  is located on groove  26 , opening first fork  24   b  may rotate this fork in a counterclockwise direction until the first fork rests against teeth  45  of first jaw  42   b  (see  FIG. 3E ). Further opening of the first fork  24   b  may push this fork against first jaw  42   b.    
     Push-rod  22  along with the loaded clips may be inserted into a catheter  35  as seen in  FIG. 3C . Catheter  35  may comprise a hollow tube with an external diameter sized to be inserted into a working lumen of endoscope  10 . The jaws of clip  40  may deflect inwards from an open configuration to a closed configuration while being inserted into catheter  35 . The internal diameter of a distal end of catheter  35  may be such that the clips in a closed configuration may slide longitudinally within the catheter freely. Push-rod  22  may be inserted into catheter  35  such that all the loaded clips are positioned within the catheter, and a proximal end of push-rod  22  protrudes from a proximal end of catheter  35 . At some distance near the distal end, the internal surface of catheter  35  may have a flange  58  designed to stop the longitudinal movement of clip  40 . In some embodiments, flange  58  may be a region of reduced diameter of catheter  35 . It is also contemplated that the flange  58  can have other configurations, such as, a protrusion of a size that prevents the passage of a loaded clip past the protrusion. 
     In some embodiments, the distance of flange  58  from the distal most end of catheter  35  may be factor in determining the number of clips  40  that may be loaded on a push-rod positioned within the catheter. The internal dimensions of catheter  35  may be configured to facilitate locating a clip on groove  28  of push-rod  22 . For instance, pulling push-rod  22  in a proximal direction from the proximal end of catheter  35  may move the push-rod, along with the loaded clips, into the catheter towards the proximal end. During this movement, a loaded clip may run into flange  58 . The flange may thus prevent longitudinal movement of the clip towards the proximal end. Further pulling of the push-rod towards the proximal end may cause the push-rod to slide on the through-hole  46 , thereby positioning the clip on the groove. 
     The catheter  35  with the inserted push-rod  22  may now be delivered to the access site  55  through a working lumen of the endoscope  10 . The endoscope may be positioned within the body such that the distal end  90  of the endoscope  10  is proximate the access site  55 .  FIG. 3D  illustrates one embodiment of delivery of the clip  40  to an access site  55 . The catheter  35  may be delivered such that loaded clip  40  extends from the distal end  90  of the endoscope  10 . While thus positioned, pushing the push-rod  22  into the catheter  35  from the proximal end may extend the push rod  22  with the loaded clip  40  out of the distal end of the catheter  35 . When the push-rod  22  is pushed into the catheter  35  to extend the clip  40  positioned on the groove  28  from the distal end of the catheter  35 , the jaws of the clip  40  may spring back to its open configuration. It is contemplated that in some embodiments, the jaws may not return completely to their pre-deformed configuration, but may retain some plastic deformation. The distal end  90  of the endoscope  10  and/or the distal end of the catheter  35  may now be maneuvered to position extended clip  40  proximate one tissue edge (first tissue edge  70   a  or second tissue edge  70   b ). 
     Clip  40  may now be used to grasp these separated tissue edges.  FIG. 3E  illustrates grasping second tissue edge  70   b  between the first fork  24   b  and the first jaw  42   b . To grasp the second tissue edge  70   b , the clip  40  may be maneuvered to locate the second tissue edge  70   b  between the first fork  24   b  and the first jaw  42   b . When clip  40  is suitably positioned, the actuation device may be used to open first fork  24   b . Opening the first fork  24   b  may rotate the first fork  24   b  about the hinge  26  in a counterclockwise direction. The opening first fork  24   b  may force the trapped second tissue edge  70   b  against the teeth  45  of the first jaw  42   b  thereby firmly grasping the second tissue edge  70   b  between the first fork  24   b  and the first jaw  42   b . While thus grasping the second tissue edge  70   b , the endoscope  10  or catheter  35  may be maneuvered to the location of the first tissue edge  70   a . When the clip  40  is suitably positioned proximate the first tissue edge  70   a , the second jaw  42   a  may be opened to grasp the first tissue edge  70   a  between the second jaw  42   a  and the first fork  24   a .  FIG. 3F  illustrates clip  40  grasping the first tissue edge  70   a.    
     With the two tissue edges firmly grasped between the jaws and the forks, push-rod  22  may be pulled towards the proximal end to force clip  40  towards the catheter  35 .  FIG. 3G  illustrates one embodiment of the clip  40  being pulled towards the catheter  35 . While the clip  40  is being retracted into the catheter  35 , the open jaws of the clip are pushed inwards by the walls of the catheter  35 . The reaction force of the catheter  35  on the open jaws of the clip may deform the jaws with the tissue edges and the forks sandwiched between the jaws. In some embodiments, part or all of clip  40 , with the tissue edges sandwiched between its jaws, may enter the distal end of catheter  35  as the push-rod  22  is pulled into the catheter  35 . 
     In some embodiments, further pulling of the push-rod  22  from the proximal end of the catheter  35  may further pull the forks out from between the jaws of the clip  40 , leaving the tissue edges sandwiched between the deformed jaws of the clip. In embodiments where a part of the deformed clip  40  enters the distal end of catheter  35  upon retraction of the push-rod  22 , retracting the catheter  35  away from the access site  55  may stretch the organ wall  70  to allow the clip  40  to be pulled out of the distal end of the catheter  35  with the first tissue edge  70   a  and second tissue edge  70   b  sandwiched between its jaws.  FIG. 3H  illustrates a deformed clip  40  with the tissue edges grasped between its jaws. Clip  40  may thus close aperture  80  by joining the two tissue edges together. The action of retracting the push-rod  22  into catheter  35  may also position another loaded clip  40  in the groove  28  of the push-rod  22  as described previously. 
     Although the description above describes the method of closing a puncture with two tissue edges using clip  40 , the same general approach can be used to close an aperture  80  having more than two tissue edges. To close a puncture with more than two tissue edges, a clip with multiple jaws may be used. For instance, clip  40   a  with three jaws depicted in  FIG. 2B , may be used to close an aperture  80  with three tissue edges. In this embodiment, the push-rod  22  may include three forks that may be independently opened and closed from outside the body. The clip  40   a  may be loaded on the push-rod  22  and delivered to the access site  55  as described earlier. At the access site  55 , the first tissue edge may be grabbed between a jaw and a fork and dragged to the location of the second tissue edge. A second tissue edge may then be grabbed between a second jaw and a fork. The distal end of the catheter  35  may then be maneuvered to the location of a third tissue edge, where the third tissue edge may be grabbed between the third fork and the jaw. Push rod  22  may then be retracted into the catheter to deform the jaws of clip  40   a  as discussed earlier. The push-rod  22  may be further retracted to extract the forks from between the jaws, thereby leaving the tissue edges pressed together by the deformed jaws. Although the description above describes a clip having jaws equal to the number of forks, this is not a requirement. That is, in some embodiments, the number of jaws of a clip may be different than the number of forks. 
     It is also contemplated that a device with two jaws (such as clip  40  depicted in  FIG. 2A ) may be used to close an aperture with more than two tissue edges. In such an application, two or more tissue edges may be grabbed between a jaw and a fork. A first tissue edge may be firmly embedded in the teeth  45  of the jaw so that it may not be released when the jaw is opened to grasp a second tissue edge. 
       FIG. 4  illustrates another embodiment of a tissue approximation clip  140  that may be used to close the aperture  80 . Clip  140  of  FIG. 4  may be attached to a distal end of an elongate member  122 , and may be delivered to the access site  55  through the working lumen of the endoscope  10 . In some embodiments, the elongate member  122  with the clip  140  may be delivered to the access site  55  via a catheter inserted into the working lumen. The elongate member  122  may connect the clip  140  to an actuation device attached to the proximal end thereof. The elongate member  122  may include mechanisms, such as links or cables, that may allow the actuation device to operate the clip  140 . These actuation mechanisms may be similar to those discussed with reference to clip  40  of  FIG. 3A , or may be different. The clip  140  may protrude from the distal end of the endoscope  10  to operate on the aperture  80 . 
     Clip  140  may include three jaws—a first jaw  142   a , a second jaw  142   b , and a fixed center jaw  124 . The jaws may have a corrugated surface, teeth  145 , or other surface modifications on its facing sides. Similar to the opening left and right forks of the embodiment shown in  FIGS. 3A-3H , the first jaw  142   a  and the second jaw  142   b  may be movable and may be opened and closed using the actuation mechanism. Closing the first jaw  142   a  may actuate this jaw about a hinge  126  until the teeth  145  on its surface presses against the teeth  145  on the fixed center jaw  124 . And, closing the second jaw  142   b  may actuate this jaw about the hinge  126  until its teeth  145  meets the teeth  145  of the center jaw  124 . The jaws may be opened by actuating the jaws in the opposite direction. In some embodiments, the first jaw  142   a  and the second jaw  142   b  may be biased to remain in the closed configuration. In these embodiments, the jaws may be opened by applying an opening force to overcome the biasing force. The jaws may actuate to a closed configuration when the opening force is removed. In some embodiments, when a jaw is closed against the center jaw, teeth  145  on both jaws lock to keep the jaw in a closed configuration. 
       FIGS. 5A-D  illustrate a method of using clip  140  to approximate tissue edges  70   a  and  70   b  and close the aperture  80 . The clip  140  may be attached to the distal end of the elongate member  122  and delivered to the site of an aperture  80  via the working lumen of the endoscope  10 .  FIGS. 5A and 5B  illustrate the clip  140  grasping a tissue edge  70   a  at the access site  55 . At the access site  55 , the endoscope  10  is maneuvered to position a first tissue edge  70   a  between the center jaw  124  and another jaw of the clip, for instance the first jaw  142   a . The actuation device is then actuated to close the first jaw to firmly grasp the first tissue edge  70   a  between the first jaw  142   a  and the center jaw  124 . In the closed configuration, the teeth  145  of the first jaw  142   a  and the center jaw  124  engage, thereby locking the first jaw  142   a  in the closed configuration. 
     The clip  140  with the grasped first tissue edge  70   a  is maneuvered to the site of a second tissue edge  70   b . The second tissue edge  70   b  is positioned between the second jaw  142   b  and the center jaw  124 , and the second jaw  142   b  closed to lock the second tissue edge  70   b  between the teeth  145  of these jaws.  FIG. 5C  illustrates the first and second tissue edges  70   a  and  70   b  firmly grasped by clip  140 . The clip  140  may thus close the aperture  80  by joining together the tissue edges that form the aperture  80 . Once the tissue edges are thus joined, the clip  140  may be released.  FIG. 5D  illustrates the released clip  140 . The released clip  140  may keep the aperture  80  closed allowing the natural healing process to grow fresh tissue around the joined tissue edges. 
     In general, a clip may be released from an elongate member by any means. In some embodiments a frangible link or an electrolysis link may be used to release a clip from an elongate member. Clip  140  also may be released from the elongate member by any other suitable method, including methods that use the actuation mechanism. In some embodiments, a clasp may retain the clip  140  on the distal end of the elongate member  122 . In these embodiments, the actuation mechanism may operate the clasp to release the clip  140 . In some embodiments, the distal end of the elongate member  122  may have threads that mate with threads on a mating face of the clip  140 . In these embodiments, rotating the elongate member  122  about its longitudinal axis may unscrew the clip  140  from the elongate member  122 , and release the clip  140 . 
       FIG. 6  illustrates another embodiment of a tissue approximation clip  240  that may be used to close the aperture  80 . Clip  240  may include a first jaw  242   a  and a second jaw  242   b  hinged to an elongate member  222  at hinges  226   a  and  226   b  (see  FIG. 7A ), respectively. The first jaw  242   a  and the second jaw  242   b  may also include teeth  245  or other surface irregularities on facing surfaces. The clip  242  may be located at the distal end of the elongate member  222 , and may be delivered to an access site  55  within a catheter  35 . The catheter  35  may be delivered to the access site  55  through a working lumen of an endoscope  10 . The first jaw  242   a  and the second jaw  242   b  may be configured to slide individually on elongate member  222  to extend from the distal end of the catheter  35 . A hook  224  having barbs, may also be located between the first jaw  242   a  and the second jaw  242   b . The barbs may be sharp needle like features that protrude from the distal end of hook  224 , or just a raised profile at the distal end of hook  224 . Clip  240  may close aperture  80  by clamping the tissue edges between its jaws.  FIGS. 7A-E  illustrate a method of using clip  240  to approximate and join tissue edges. 
     When the distal end of the catheter  35  is proximate the first tissue edge  70   a , the first jaw  242   a  along with the hook  224  may be extended from within the catheter  35 . The jaws may be biased to open when released from within the catheter  35 . The catheter  35  and/or the endoscope  10  may be positioned to locate the first tissue edge  70   a  between the extended jaw and the hook  224 .  FIG. 7A  shows device  240  with the first tissue edge  70   a  located between the first jaw  242   a  and the hook  224 . When the tissue is appropriately positioned, the first jaw  242   a  along with hook  224  may be retracted into catheter  35 . A catch or a feature on an inside surface of the catheter  35  may prevent the second jaw  242   b  from retracting further into catheter  35  when the first jaw  242   a  is retracted. Withdrawing the catheter  35  may force the first jaw  242   a  to a closed configuration, trapping the tissue between the jaw and the hook  224 .  FIG. 7B  illustrates the clip  240  with the first tissue edge  70   a  grasped by the first jaw  242   a  and the hook  224 . When the first jaw  242   a  closes over the first tissue edge  70   a , the barbs of hook  224  and teeth  245  of first jaw  242   a  may lock, or cooperate together in another manner, to hold first tissue edge  70   a  firmly in place. In an embodiment of clip having sharp barbs and teeth, these barbs and teeth may pierce through the first tissue edge  70   a  to firmly hold the tissue edge between the jaw and the hook. 
     The endoscope  10  and/or catheter  35  may then be maneuvered to the location of the second tissue edge  70   b , and the second jaw  242   b  extended from within the catheter  35  with first jaw  242   a , hook  224 , and first tissue edge  70   a . The second jaw  242   b  may spring open and position itself over the second tissue edge  70   b , when released from within the catheter  35 .  FIG. 7C  shows clip  240  with the second tissue edge  70   b  located between the second jaw  242   b  and the hook  224 . Once the jaw is appropriately positioned, the second jaw  242   b  may be retracted into the catheter  35  to close the second jaw  242   b  over the second tissue edge  70   b .  FIG. 7D  illustrates the clip  240  in the retracted configuration. Closing the second jaw  242   b  over the second tissue edge  70   b  may also force the second tissue edge  70   b  against the hook  224 , forcing the barbs and the teeth into the second tissue edge  70   b.    
     When the tissue edges are securely joined together, the clip  240  may be released and the catheter  35  withdrawn from the access site  55 .  FIG. 7E  illustrates the release of the clip  240  from the catheter  35 . The clip  240  along with the hook  224  may be separated from the elongate member  222  by activating a detachment mechanism on the actuation mechanism. In some embodiments, retracting the catheter  35  and/or elongate member  222  may stretch the organ wall  70  exerting a force on the clip. This force may break the connection of the clip to the elongate member  222 , thereby releasing the clip  240  from the catheter  35 . As indicated earlier, other detachment mechanisms may also be used to separate clip  240  from elongate member  222 . The released clip  240  may remain in the body closing the aperture  80 . 
     In some embodiments, only the hook  224 , with the first tissue edge  70   a  and the second tissue edge  70   b  attached to its barbs, is released. In these embodiments, the actuation member activates a detachment mechanism releasing the hook  224  from the elongate member  222 . In these embodiments, the hook  242  may hold the tissue edges together allowing subsequent tissue growth to permanently join the tissue edges together. 
       FIG. 8A  illustrates another embodiment of a clip  340  that may be used to close aperture  80 . As in clip  40 , clip  340  may have two jaws, a first jaw  342   a  and a second jaw  342   b , joined by a midsection having a through-hole  346  therein. An inside surface of the two jaws may have a corrugated surface or teeth  345 . The first jaw  342   a  and the second jaw  342   b  may be symmetric about a plane passing through a center of the through-hole  46 . It is also contemplated that in some embodiments, clip  340  may have a different structure, for instance, an annular structure. 
     Clip  340  may be delivered to an access site  55 , mounted on the surface of a sheath  324 . The sheath  324  may be delivered to the access site  55  via a catheter  35  which slides within a working lumen of the endoscope  10 . In some embodiments, the catheter  35  may be eliminated, and the sheath  324  may be delivered to the access site  55  directly via the working lumen. As described above with reference to other embodiments, clip  340  may transform from a closed configuration within the catheter  35  to an open configuration outside the catheter  35 . When the sheath  324  is pulled into the catheter  35 , the clip  340  may also retract into the catheter  35  until the longitudinal movement of the clip is blocked by flange  58 . Flange  58  may be a feature on the internal surface of the catheter  35  that blocks a clip from sliding from the distal end of the catheter  35  to the proximal end of the catheter  35 . 
     The sheath  324  may have two lumens running longitudinally therethrough. These lumens may include a first lumen  324   a  and a second lumen  324   b  running from a distal end to a proximal end of the sheath  324 . Two endoscopic instruments with grasper end effectors, a first grasper  326   a , and a second grasper  326   b , may be delivered to the access site  55  through the lumens of the sheath  324 . The grasper end effectors may include any instrument, for example, forceps, barbed needles, etc., configured to grasp any object within the body. In some embodiments, the first grasper  326   a  may be delivered to the access site  55  through the first lumen  324   a , and the second grasper  326   b  through the second lumen  324   b . It is also contemplated that, in some embodiments, both graspers may be delivered to the access site  55  through the same lumen. The graspers may also be extracted from the access site  55  through the lumens. Linkages  322   a  and  322   b  may connect the first grasper  326   a  and the second grasper  326   b , respectively, to one or more actuation mechanisms at the proximal end of the endoscope  10 . These actuation mechanisms may operate the graspers at the access site  55 . Operating the graspers may include translating and rotating the graspers at the access site  55 , and moving jaws of the grasper to grasp cut/separated tissue edges between these jaws. 
     At the access site  55 , each grasper may be maneuvered to the location of a piece of tissue. The first grasper  326   a  may grasp the first tissue edge  70   a  and the second grasper  326   b  may grasp the second tissue edge  70   b . The graspers, along with the tissue, may then be retracted from the access site  55 . The sheath  324  may also be pulled into the catheter  35 , pulling the grasped tissue edges and the clip  340  along with it.  FIG. 8B  illustrates the retraction of the sheath  324  into the catheter  35 . During retraction, the movement of the clip  340  may be blocked by the flange  58 . Continued retraction of the sheath  324  may plastically deform the jaws of the clip  340  by forcing them together. The first tissue edge  70   a  and the second tissue edge  70   b  may be trapped between the deformed jaws, thereby joining the tissue edges together. The actuation device may then be activated to release the tissue edges from the graspers  326   a ,  326   b.    
     In some embodiments, multiple clips  340  may be mounted on the surface of sheath  324  (as described with reference to clip  40  shown in  FIGS. 2A-3H ). After a first clip is deployed, another clip  340  may slide down the sheath  324  and extend out of the distal end of the catheter  35 . This second clip may be used to join tissue edges as described earlier. 
       FIGS. 9A-9D  illustrate another embodiment of a clip that may be used to close aperture  80 . Clip  440  of this embodiment may be delivered to the access site  55  at the distal end of an elongate member  424  extending from a working lumen of the endoscope. Similar to graspers  326   a ,  326   b  of the embodiment in  FIGS. 8A-8B , a first grasper  426   a  and a second grasper  426   b  may also be delivered to the access site  55  through the elongate member  424 . The graspers  426   a ,  426   b  may be operated at the access site  55  by one or more actuation mechanisms external to the body.  FIG. 9A  illustrates clip  440  positioned at the access site  55 . The graspers  426   a ,  426   b  may extend to the access site  55  through holes or cavities in clip  440 . In some embodiments, the first grasper  426   a  may extend into the access site  55  through a first through-hole  446   a  and the second grasper  426   b  may extend into the access site  55  through a second through-hole  446   b . It is also contemplated that, in some embodiments, both the first and the second graspers may extend through the same through-hole. 
     As described with reference to  FIG. 8B , the first grasper  426   a  may grasp the first tissue edge  70   a  and draw it into clip  440  and the second grasper  426   b  may grasp the second tissue edge  70   b  and draw it into the clip  440 . The tissue edges may be drawn into the clip by retracting the grasper into the elongate member  424 .  FIG. 9B  illustrates a view of clip  440  with the first and second tissue pieces grasped by the graspers. When both tissue edges are drawn into the clip  440 , the actuation mechanism may be activated to release a fastener  450  to bind the tissue edges together. Fastener  450  may include a barb or any object configured to join the tissue edges. In some embodiments, the fastener  450  may be released from the side of clip  440  and may penetrate the first and second tissue pieces to join them together. However, it is also contemplated that fastener  450  may be released from the clip in another manner.  FIG. 9C  illustrates the fastener  450  joining the two tissue edges together. After the tissue edges are securely bound together, the fastener  450  may be released from the clip  440 . In some embodiments, the fastener  450  may be released by activating the actuation mechanism. It is also contemplated that, in some embodiments, the clip  440  may be retracted after joining the tissue edges together, and the staple may be pulled off the clip by the force of the stretched stomach wall.  FIG. 9D  illustrates a view of the released fastener  450  joining the two tissue edges together. 
       FIG. 10  illustrates an embodiment of a clip having an attached barb  550 . The clip  540  attached to an elongate member  524  may be delivered to the access site  55  through the working lumen of the endoscope  10 . As in previously described embodiments, the clip  540  may transform to an open configuration as it extends from the distal end  90  of the endoscope  10 . The clip  540  may include a first jaw  542   a  and a second jaw  542   b  connected at a hinge  526 . The elongate member  524  may include linkages that connect the jaws to an actuation mechanism outside the body. The actuation mechanism may be configured to move the jaws of clip  540  towards each other and, thereby, form a closed configuration. 
     A barb  550  may be attached to one of the jaws, for instance, the first jaw  542   a , of clip  540 . The barb  550  may be hinged to the first jaw  542   a  at a first end  548   a . The second end  548   b  of the barb  550  may form a sharp point or an arrowhead. In some embodiments, barb  550  may also include spikes (similar to spikes  652  on barb  650  of  FIG. 12A ) that protrude from a surface of the barb  550 . The barb  550  may be spring loaded and the second end  548   b  of the barb  550  may be retained on the first jaw  542   a  by a catch or another mechanism. The actuation device may be configured to release the catch. Upon release of the catch, the barb  550  may be configured to transform to a deployed configuration. In the embodiment of clip depicted in  FIG. 10 , the barb  550  may rotate about the first end  548   a  and snap to a second configuration (as seen in  FIG. 11B ). In the second configuration, the second end  548   b  of the barb  550  may project from the first jaw  542   a  and point towards the second jaw  542   b.    
     The second jaw  542   b  may have a hole  528  to enable the second end  548   b  of the barb to protrude through when the clip  540  is in a closed configuration. The second jaw  542   b  may also features designed to impart some compliance to the second jaw  542   b . In  FIG. 10 , these compliant features are depicted as slender members arranged as a cross-hair around the hole  528 . These members may bend slightly when an out of plane force is applied on the members, thereby providing compliance to the second jaw  542   b . The purpose of the compliance will become clearer in the discussion in reference to the operation of clip  540 . In some embodiments, other forms of compliance enhancing features may be incorporated into the second jaw  542   b . It is also contemplated that, in some embodiments, the compliance enhancing features may be eliminated. 
       FIGS. 11A-E  illustrate the use of clip  540  to approximate tissue edges (for example, first tissue edge  70   a  and second tissue edge  70   b ), and close aperture  80 . The endoscope  10  may be maneuvered to locate the first tissue edge  70   a  between the open jaws of clip  540 . The actuation device may then be actuated to grasp the first tissue edge  70   a  by closing the jaws.  FIG. 11A  depicts a view of clip  540  with the first tissue edge  70   a  grasped between its jaws. With the tissue firmly grasped, the barb  550  may be released from the first jaw  542   a . Releasing the barb  550  may rotate, or otherwise actuate, the spring loaded barb  550  about the first end  548   a  to the second configuration. While moving to the second configuration, the sharp second end  548   b  may pierce through the grasped first tissue edge  70   a .  FIG. 11B  depicts a view of the clip  540  with the grasped first tissue edge  70   a  pierced by the barb  550 . In some embodiments, the grasped tissue may be forced against the surface of the second jaw  542   b  while the barb tries to pierce through the tissue from the opposite side. Compliance enhancement features of the second jaw  542   b  may enable the barb  550  to pierce the tissue without undue trauma. 
     The clip  540  may again be opened using the actuation mechanism.  FIG. 11C  illustrates a view of clip  540  with the jaws open. The shape of the second end  548   b  may prevent the pierced first tissue edge  70   a  from being released when the jaws of the clip  540  are opened. The endoscope may again be maneuvered to position the second tissue edge  70   b  between the jaws of clip  540 . The jaws may now be closed to grasp the second tissue edge  70   b  between the jaws. When the jaws rotate to the closed configuration, the pointed second end  548   b  of the barb  550  may pierce the second tissue edge  70   b .  FIG. 11D  depicts the clip  540  with both tissue edges pierced by the barb  550 . The clip  540  may again be opened and barb  550  detached from the first jaw  542   a  to release the tissue edges joined together by the barb  550 .  FIG. 11E  illustrates the tissue pieces joined by the barb  550 . In some embodiments, the barb  550  may be detached by releasing the first end  548   a  from the first jaw  542   a  using the actuation mechanism. In embodiments of clip  540  with spikes on the barb  550 , these spikes may assist in preventing the tissue edges from slipping off the barb  550 . In some embodiments, retracting the clip away from the access site  55  may stretch the organ wall  70 . The stretched organ wall may then pull the first end  548   a  off the first jaw  542   a.    
     In some embodiments, the entire clip  550  may be released from the elongate member  524  after the tissue edges are joined together with the barb. Releasing the clip  540  may be accomplished by the actuation device or the force exerted by the stretched organ wall  70 . 
       FIGS. 12A-12E  illustrate another embodiment of a clip with a barb  650  used to join cut/separated tissue edges. In the embodiment of  FIG. 12A , the clip  640  may include a first jaw  642   a  and a second jaw  642   b  attached together at a hinge  626 . Clip  640  may be delivered and operated at the access site  55  similar to clip  540  of the previous embodiment. A barb  650  may be attached to the first jaw  642   a  at a first end  648   a . The first end  648   a  may be pointed and may be retained on first jaw  642   a  by a catch or other retention features on first jaw  642   a . The second end  648   b  of the barb  650  may project from the first jaw  642   a  and point towards the second jaw  642   b . The second end  648   b  of the barb  650  may also be pointed. The second jaw  642   b  may also include retention features that are configured to couple to the second end  648   b  and retain the barb  650  to the second jaw  642   b . The barb  650  may also include spikes  652  on its surface. The barb  650  may include spikes  652  pointed to both the first end  648   a  and the second end  648   b.    
     The second tissue edge  70   b  may be positioned between the jaws of the clip  640  and the jaws closed. While closing, the barb  650  may pierce through the second tissue edge  70   b .  FIG. 12B  illustrates a view of clip  640  with the grasped second tissue edge  70   b . While in the closed configuration, the second end  648   b  of the barb  650  may engage with the retention features on the second jaw  642   b . The jaws may again be opened to grasp the first tissue edge  70   a .  FIG. 12C  illustrates a view of the clip  640  with the jaws opened. Barb  650  may now be retained by the retention features of the second jaw  642   b . The spikes  652  on the barb  650  may prevent the second tissue edge  70   b  from being released when the jaws are opened. The first tissue edge  70   a  may be positioned between the jaws and the jaws closed again to grasp the first tissue edge  70   a .  FIG. 12D  illustrates the first and second tissues grasped between the jaws of clip  640 . The sharp first end  648   a  of barb  650  may pierce through the first tissue edge  70   a  when the jaws are closed. The barb  650  may thus pierce through and join the first tissue edge  70   a  and second tissue edge  70   b . As in the previous embodiment, the clip  640  may now be opened and the barb  650  released from the clip  640 . The barb  650  may keep first tissue edge  70   a  and second tissue edge  70   b  joined. In some embodiments, the entire clip  640  may be released from the elongate member  624  to leave behind the clip  640  joining the two tissue edges together. 
       FIGS. 13A-13E  illustrate another embodiment of a clip used to attach tissue edges. As in embodiments above, clip  740  may also include a first jaw  742   a  and a second jaw  742   b  connected by a hinge  726 . Clip  740  attached to an elongate member  722  may also be delivered to the access site  55  through the working lumen of an endoscope  10  and may be operated by an actuation mechanism external to the body. As in clip  40 , clip  740  may also include a hollow through-hole  746  at a location between the jaws. 
     A claw  750  attached to a flexible part  724  may be delivered to the access site  55  through the through-hole  746 . The flexible part  724  may be manipulated external to the body to control the claw  750  at the access site  55 . With the jaws of the clip  740  open, the claw  750  attached to the flexible part  724  may be advanced through an aperture  80 .  FIG. 13B  shows the claw  750  on an opposite side of the puncture. The flexible part  724  and the claw  750  may now be retracted into the elongate member  722 . The claw  750  may snag and drag the aperture  80  along with the first tissue edge  70   a  and second tissue edge  70   b  into clip  740 . Claw  750  may have any shape configured to snag the tissue edges and draw them into the clip  740 . 
       FIG. 13C  illustrates a view of the clip  740  with the snagged stomach wall positioned between its jaws. Once the first tissue edge  70   a  and the second tissue edge  70   b  are appropriately positioned between the jaws, clip  740  may be closed.  FIG. 130  illustrates the clip  740  in a closed configuration. The closed clip  740  may grasp the tissue edges, thereby joining them together. The clip  740  may now be released and the endoscope retracted from within the body. 
       FIGS. 14A-14F  illustrate another embodiment of a clip  840  used to fasten first tissue edge  70   a  and second tissue edge  70   b  at access site  55 . Clip  840  may be comprised of multiple arms, for instance, a first arm  842   a  and a second arm  842   b . Although clip  840  is depicted with two arms, different embodiments of clip  840  may have a different number of arms. Clip  840  may also include a center arm  850  positioned between first arm  842   a  and second arm  842   b . Center arm  850  may include a barb  858  positioned thereon. In some embodiments, barb  858  may be positioned at a distal end of center arm  850 . Although in  FIG. 14A , barb  858  is shown as a projection on center arm  850 , barb  858  may have any shape and configuration. For instance, barb  858  may be sharp and needle shaped in some embodiments. First arm  842   a  and second arm  842   b  may be attached to the center arm  850  at attachment sections  846   a  and  846   b  respectively, at a proximal region of the center arm  850 . Any attachment mechanism may be used to attach the first and second arms  842   a  and  842   b  to the center arm  850 . Proximal to attachment sections  846   a  and  846   b , center arm  850  may include protrusions  852   a  and  852   b  extending in a radial direction. In some embodiments, these protrusions may be spring loaded. In these embodiments, the protrusions  852   a  and  852   b  may be configured to compress or depress inwards towards center arm  850  upon the application of a radially inward force. In other embodiments, protrusions  852   a  and  852   b  may not be spring loaded, but may be otherwise configured to move towards the center arm  850  upon the application of a radially inward force. For example, protrusions  852   a  and  852   b  may be comprised of a compressible material. 
     From their respective attachment sections at the proximal region of center arm  850 , the first and second arms  842   a  and  842   b  may extend a distance longitudinally, and distally, along the length of center arm  850 . The first and second arms  842   a  and  842   b  may then be bent away from the center arm  850  such that distal regions of these arms make an angle with a distal region of center arm  850 . The first arm  842   a  may be bent away from the center arm  850  at a first section  844   a , and the second arm  842   b  may be bent away from center arm  850  at a second section  844   b . The first section  844   a  may be displaced longitudinally, or offset, from second section  844   b.    
     A push-rod  822 , coupled to a proximal end of clip  840 , may be configured to extend the clip  840  from the distal end of a catheter  835  or an endoscope to access site  55 . Actuating the push-rod  822  in a distal direction may move the push-rod  822  into the body, and may extend clip  840  out of the distal end of catheter  835 . Actuating the push-rod in a proximal direction may retract the distal end of the push-rod  822  along with clip  840  into the catheter  835 . 
     Clip  840  may also include an end cap  860  positioned at a proximal end of first and second arms  842   a  and  842   b . The push-rod  822  may pass through a through-hole  866  on an end piece  864  positioned at a proximal end of the end-cap  860 , to couple with the proximal end of clip  840 . In some embodiments, end piece  864  may be integral with end cap  860 , while in other embodiments, end piece  864  may be a part separate from end cap  860 . Although end cap  860  may be fitted with the end piece  864  by any means, in some embodiments, the end piece  864  may be interference fitted with the proximal end of the end cap  860 . Actuating push-rod  822  in a proximal direction may pull clip  840  at least partially into end cap  860 . As clip  840  slides into end cap  860 , the walls of the end cap  860  may contact the first and second arms  842   a  and  842   b , and apply a radially inward force on the arms. This radially inward force may deflect these arms towards center arm  850 . Since first section  844   a  and second section  844   b  of the two arms are longitudinally displaced from each other, end cap  860  may contact and deflect one of these arms towards the center arm  850  at least partially before contacting and deflecting the other arm towards the center arm  850 . 
       FIG. 14B  illustrates a configuration of clip  840  with clip  840  partially retracted into end cap  860 . In the embodiment of clip  840  illustrated in  FIG. 14 b   , the end cap  860  contacts and deflects the second arm  842   b  towards center arm  850  before the end cap  860  contacts the first arm  842   a . When used in a procedure to fasten tissue segments  70   a  and  70   b , endoscope  10  or catheter  835  with clip  840  may be maneuvered to locate one of these tissue edges, for example second tissue edge  70   b  in  FIG. 14 b   , between center arm  850  and second arm  842   b . The push-rod  822  may then be actuated in a proximal direction to retract clip  840  partially into end cap  860 . As the clip  840  slides within end cap  860 , internal walls of the end cap  860  may slide on the protrusions  852   a  and  852   b , and apply a radially inward force on these protrusions. This radially inward force may depress the protrusions  852   a  and  852   b  radially inwards towards center arm  850 , thereby allowing the clip  840  to slide within end cap  860 . Walls of end cap  860  may also contact and apply a radially inward force on second arm  842   b  to deflect the second arm towards center arm  850 . As the second arm  842   b  deflects towards center arm  850 , second tissue edge  70   b  may get held between these arms.  FIG. 14C  illustrates an embodiment of clip  840  with second tissue edge  70   b  held between center arm  850  and second arm  842   b.    
     The distal end of endoscope  10  or catheter  835  may then be repositioned so that another tissue edge, for instance first tissue edge  70   a , may be positioned between first arm  842   a  and center arm  850 . Further actuation of the push-rod  822  towards the proximal end may move the clip  840  further into end cap  860 . As the clip  840  moves further into the end cap  860 , walls of the end cap  860  may contact and deflect the first arm  842   a  towards the center arm  850  with first tissue edge  70   a  between the first arm  842   a  and center arm  850 . Further actuation of the push-rod  822  towards the proximal end may engage the protrusions  852   a  and  852   b  of center arm  850  with mating features  862   a  and  862   b  on end cap  860 . In some embodiments, mating features  862   a  and  862   b  may be cavities in end cap  860  that are dimensioned to fit the protrusions  852   a  and  852   b  therein. Alignment of the protrusions with the mating features may relieve any constraining force from the protrusions, and allow the protrusions to spring back, or recover, to their original pre-depressed configuration. Engagement of the protrusions  852   a  and  852   b  with the mating features on end cap may lock the first and second arms  842   a  and  842   b  in a closed configuration, where these arms press against center arm  850  with the first and second tissue pieces  70   a  and  70   b  firmly grasped between them. In embodiments where center arm  850  includes a barb  858 , the barb  858  may also assist in firmly securing the tissue edges between the arms.  FIG. 14D  illustrates an embodiment of clip  840  with the arms locked in a closed configuration. 
     Engagement of the protrusions  852   a  and  852   b  with the mating features  862   a  and  862   b  on end cap  860  may also prevent the clip  840  from sliding further into the end cap  860  upon further actuation of the push-rod  822  towards the proximal end. Further actuation of push-rod  822  may stretch organ wall  70  and exert a force on the proximal end of clip  840 . This force may detach the distal end of push-rod  822  from the proximal end of clip  840 . As in other embodiments, any clip release mechanism (such as, threaded connections, frangible link, electrolysis link, etc.) may be used to separate push-rod  822  from the clip  840 .  FIG. 14E  illustrates an embodiment of clip  840  with the push-rod  822  detached from clip  840 . 
     After the push-rod  822  detaches from clip  840 , further retraction of the push-rod  822  towards the proximal end may cause a protrusion  824  on the push-rod  822  to abut against end piece  864 . In some embodiments, the push-rod  822  and end cap  860  may be dimensioned such that protrusion  824  of the push-rod abuts against end piece  864  when the push-rod  822  detaches from clip  840 . Although protrusion  824  is depicted as a bend in push-rod  822 , the protrusion  824  may be of any form. Further actuation of the push-rod  822  may force the protrusion  824  against end piece  864  and cause the end piece  864  to be dislodged from the proximal end of the end cap  860 .  FIG. 14F  illustrates an embodiment of clip  840  with the end piece  864  separated from end cap  860 . The push-rod  822  may now be retracted out of the body through the catheter or endoscope. 
     Other methods may also be used to disengage the push-rod  822  from the end cap  860 . In some embodiments, through-hole  866  may be configured to allow the push-rod  822  to be rotated and extracted from the end cap  860 . For example, the through-hole  866  may have two different cross-sectional shapes along two directions. In these embodiments, a cross-section of the through-hole along one direction may correspond to a diameter of the push-rod  822 , and the cross-section of the through-hole along another direction may correspond to the thickest region of the protrusion  824 . Rotating the push-rod  822  to align protrusion  824  with the direction having a matching cross-section of the through-hole will allow the push-rod to be removed from end cap  860 . In some embodiments, the protrusion  824  may be a c-shaped bend on push-rod  822  and the through-hole  866  cross-sectional shapes along two different directions may correspond to a diameter of the push-rod  822  and a dimension of the c-shaped bend on push-rod  822 . In such an embodiment, rotation of the push-rod  822  may extract the push-rod  822  through the through-hole  866 . In some embodiments, rotation of the push-rod  822  may retract the push-rod  822  partly through the through-hole  866  and engage the end piece  864  with the push-rod  822 . In these embodiments, further actuation of the push-rod  822  may detach the end piece  864  from the end cap  860 , leaving clip  840  in a locked configuration grasping the first and second tissue edges  70   a  and  70   b.    
     It will be apparent to those skilled in the art that various modifications and variations can be made in the disclosed systems and processes without departing from the scope of the invention. For instance, an adhesive, tissue growth promoter, or another agent may be used in conjunction with any clip to promote the fastening of the tissue edges or the healing process. Also, any part of the clip may be bioabsorbable or conduct heat and/or electricity to aid in tissue fastening or the healing process. Although the disclosure discusses several embodiments of a clip used in an endoscopic procedure, in general, clips of the current disclosure may be used to approximate tissue edges in any medical procedure, such as in conventional surgery or other types of medical procedures. Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope of the invention being indicated by the following claims.