Abstract:
A method of attaching a knotting element to a suturing device including the steps of providing an adapter for insertion into a body, the adapter having a proximal end and an open distal end. Providing a knot tying element for tying suture together. Releasably attaching the distal end of the adapter to the knot tying element by inserting a proximal end of the knot tying element into the open distal end of the adapter and thereafter rotating the knot tying device with respect to the adapter.

Description:
[0001]    This application is related to the following co-pending and commonly assigned applications, all of which are hereby incorporated herein by reference. 
         [0002]    U.S. Ser. No. 11/150,481, filed on Jun. 13, 2005 which is currently pending; U.S. Ser. No. 11/394,163 filed on Mar. 31, 2006 which is currently pending; U.S. Ser. No. 11/394,162 filed on Mar. 31, 2006 which is currently pending; U.S. Ser. No. 11/394,161 filed on Mar. 31, 2006 which is currently pending; U.S. Ser. No. 11/394,125 filed on Mar. 31, 2006 which is currently pending; U.S. Ser. No. 11/394,126 filed on Mar. 31, 2006 which is currently pending; U.S. Ser. No. 11/394,155 filed on Mar. 31, 2006 which is currently pending; U.S. Ser. No. 11/394,150 filed on Mar. 31, 2006 which is currently pending; U.S. Ser. No. 11/394,178 filed on Mar. 31, 2006 which is currently pending; U.S. Ser. No. 11/394,175 filed on Mar. 31, 2006 which is currently pending; U.S. Ser. No. 11/394,130 filed on Mar. 31, 2006 which is currently pending; U.S. Ser. No. 11/394,173 filed on Mar. 31, 2006 which is currently pending; U.S. Ser. No. 11/394,174 filed on Mar. 31, 2006 which is currently pending; and U.S. Ser. No. 11/394,168 filed on Mar. 31, 2006 which is currently pending; 
     
     FIELD OF THE INVENTION 
       [0003]    The present invention relates in general to endoscopic surgical devices and, more particularly, to a suture locking device for severing and securing the ends of a suture material within a body cavity during an endoscopic surgical procedure. 
       BACKGROUND OF THE INVENTION 
       [0004]    Endoscopic procedures have been rapidly developing over the past decade. These procedures often allow for the performance of surgical procedures with minimal trauma when compared to prior techniques requiring a large external opening to expose the internal organ or tissue requiring repair. 
         [0005]    In addition to the many areas in which endoscopic procedures have found use, endoscopic procedures have been developed for surgical procedures addressing morbid obesity. Morbid obesity is a serious medical condition. In fact, morbid obesity has become highly pervasive in the United States, as well as other countries, and the trend appears to be heading in a negative direction. Complications associated with morbid obesity include hypertension, diabetes, coronary artery disease, stroke, congestive heart failure, multiple orthopedic problems and pulmonary insufficiency with markedly decreased life expectancy. With this in mind, and as those skilled in the art will certainly appreciate, the monetary and physical costs associated with morbid obesity are substantial. In fact, it is estimated the costs relating to obesity are in excess of  100  billion dollars in the United States alone. 
         [0006]    A variety of surgical procedures have been developed to treat obesity. One procedure is Roux-en-Y gastric bypass (RYGB). This operation is highly complex and is commonly utilized to treat people exhibiting morbid obesity. Around 35,000 procedures are performed annually in the United States alone. Other forms of bariatric surgery include Fobi pouch, bilio-pancreatic diversion, and gastroplasty or “stomach stapling”. In addition, implantable devices are known which limit the passage of food through the stomach and affect satiety. 
         [0007]    RYGB involves movement of the jejunum to a high position using a Roux-en-Y loop. The stomach is completely divided into two unequal portions (a smaller upper portion and a larger lower gastric pouch) using an automatic stapling device. The upper pouch typically measures less than about 1 ounce (or 20 cc), while the larger lower pouch remains generally intact and continues to secret stomach juices flowing through the intestinal track. 
         [0008]    A segment of the small intestine is then brought from the lower abdomen and joined with the upper pouch to form an anastomosis created through a half-inch opening, also called the stoma. This segment of the small intestine is called the “Roux loop” Roux limb and carries the food from the upper pouch to the remainder of the intestines, where the food is digested. The remaining lower pouch and the attached segment of duodenum are then reconnected to form another anastomotic connection to the Roux loop limb at a location approximately 50 to 150 cm from the stoma, typically using a stapling instrument. It is at this connection that the digestive juices from the bypass stomach, pancreas, and liver, enter the jejunum and ileum to aide in the digestion of food. Due to the small size of the upper pouch, patients are forced to eat at a slower rate and are satiated much more quickly. This results in a reduction in caloric intake. 
         [0009]    As those skilled in the art will certainly appreciate, the conventional RYGB procedure requires a great deal of operative time. Because of the degree of invasiveness, post-operative recovery time can be quite lengthy and painful. In view of the highly invasive nature relating to the current RYGB procedure, other less invasive procedures have been developed. With this mind other procedures for reducing the size of the stomach have been developed. The most common form of gastric reduction surgery involves the application of vertical staples along the stomach to create an appropriate pouch. This procedure is commonly performed laparoscopically and as such requires substantial preoperative, operative, postoperative resources. 
         [0010]    As endoscopic devices and procedures have developed, surgeons have begun to employ endoscopic techniques to gastric procedures such as those discussed above in an effort to minimize trauma and reduce the time required for procedures and recovery. With the foregoing in mind, procedures and apparatuses that allow for the performance of gastric reduction surgery in a time efficient and patient friendly manner are needed. 
         [0011]    One area that has not been adequately addressed is the need for the application of sutures as these gastric, and other endoscopic, procedures are being performed. The present invention provides an endoscopic suturing device adapted for the continuous application of sutures. 
       SUMMARY OF THE INVENTION 
       [0012]    In accordance with the present invention there is provided a method of attaching a knotting element to a suturing device including the steps of providing an adapter for insertion into a body, the adapter having a proximal end and an open distal end. Providing a knot tying element for tying suture together. Releasably attaching the distal end of the adapter to the knot tying element by inserting a proximal end of the knot tying element into the open distal end of the adapter and thereafter rotating the knot tying device with respect to the adapter. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]    While the specification concludes with claims particularly pointing out and distinctly claiming the present invention, it is believed the same will be better understood by reference to the following description, taken in conjunction with the accompanying drawings, in which: 
           [0014]      FIG. 1  is an isometric view of a first embodiment for a suture locking device in an unfired position; 
           [0015]      FIG. 2  is a longitudinal, cross-sectional view of the suture locking device of  FIG. 1 ; 
           [0016]      FIG. 3  is an exploded, isometric view of the suture locking device of  FIG. 1 ; 
           [0017]      FIG. 4A  is an isolated, isometric view of the inner locking member of  FIG. 3 ; 
           [0018]      FIG. 4B  is a cross-sectional view of the inner locking member of  FIG. 4A , taken along line B-B; 
           [0019]      FIG. 5A  is an isolated, isometric view of the outer locking member shown in  FIG. 3 ; 
           [0020]      FIG. 5B  is a cross-sectional view of the outer locking member shown in  FIG. 5A , taken along line B-B; 
           [0021]      FIG. 6  is an isometric view of the adaptor and the anchor section of the launching member prior to attachment; 
           [0022]      FIG. 7A  is a cross-sectional view of the suture locking device in an initial loading stage; 
           [0023]      FIG. 7B  is a cross-sectional view of the suture locking device, in which the launching member is being inserted into the adaptor during loading; 
           [0024]      FIG. 7C  is a cross-sectional view of the suture locking device at the end stage of loading, wherein the launching member has been lowered into axial alignment with the adaptor and housing; 
           [0025]      FIG. 8A  is an isometric view of a launching member modified in accordance with an alternative embodiment for attaching the launching member to a drive cable; 
           [0026]      FIG. 8B  is an isometric view showing the launching member of  FIG. 8A  attached to the distal end of a ferrule and modified adaptor; 
           [0027]      FIG. 9  is a plan view of an exemplary deployment handle for the suture locking device; 
           [0028]      FIG. 10  is a cross-sectional view of the deployment handle of  FIG. 9 ; 
           [0029]      FIG. 11  is a cross-sectional view of the suture locking device of  FIG. 1 , showing the device threaded with suture material prior to firing; 
           [0030]      FIG. 12  is a cross-sectional view similar to  FIG. 11 , showing the inner and outer locking members engaging during the initial stages of firing; 
           [0031]      FIG. 13  is a cross-sectional view of the device of  FIG. 11 , showing the components of the knotting element engaged just prior to fracture; and 
           [0032]      FIG. 14  is a cross-sectional view similar to  FIG. 11 , showing the suture material severed and the knotting element detached from the device post firing. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0033]    During an endoscopic surgical procedure an endoscope, containing onboard visualization, is passed through a body orifice to reach a surgical site. Using the onboard visualization, small-diameter flexible instruments are manipulated at the site to join tissue segments together. Typically, the tissue segments are joined with a thin, flexible suturing material such as thread, wire or the like. Following the joining procedure, the suture material is secured in place to prevent the tissue from separating. During an open surgical procedure, in which a larger incision is made to accommodate instruments, suture materials are oftentimes joined by tying knots at the loose ends of the material. Various devices have been developed to assist the surgeon in tying knots during surgical procedures, including suture clip-type devices. In endoscopic procedures, however, knot tying can be difficult and time-consuming due to the small available working area within the endoscope. Oftentimes, the resulting knots lack the adequate holding strength or tightness to maintain the tissue junction. Accordingly, it is desirable to provide a suture locking device that can effectively be used in the confined space available in an endoscopic procedure. Additionally, it is desirable to provide a suture locking device that provides for in-line tensioning of the suture material prior to joining the suture ends together. Further, it is desirable to provide a suture locking device that can be reloaded and reused to position multiple suture knotting elements during a procedure. 
         [0034]    Referring now to the drawings in detail, wherein like numerals indicate the same elements throughout the views,  FIGS. 1-3  illustrate a first embodiment for a suturing locking device  20  of the present invention which is intended to be coupled to endoscope for insertion within a body. Suture locking device  20  deploys a knotting element during an endoscopic surgical procedure to effectively lock one or more pieces of suture material and prevent the material from dislodging within the patient&#39;s body. As shown in the Figures, suture locking device  20  comprises a substantially cylindrical, longitudinal launching member  24 . The distal portion of launching member  24  comprises an inner locking member  26 , which is shown in greater detail in  FIGS. 4A and 4B . A flange  31  is preferably located at the distal tip of inner locking member  26 . Flange  31  includes an opening into an axially-extending bore or channel  30 . Bore  30  is sized to allow a suture material  36  to be inserted therethrough. The opening to bore  30  may be tapered, as indicated by reference numeral  28 , to facilitate the threading of suture material  36  into the bore. Launching member  24  also includes an opening  35  from the proximal end of bore  30  to the exterior of the launching member, to enable suture material  36  to exit the member. Opening  35  may be angled, as indicated by reference numeral  38 , to guide suture material  36  in a proximal exit direction along the outer surface of device  20 . 
         [0035]    The outer circumference of inner locking member  26  comprises an uneven surface area that engages suture material  36  when the knotting element is deployed. In the embodiment shown, the uneven surface area comprises a plurality of spaced indentations, as indicated by reference numeral  39 . Indentations  39  are spaced apart distal of suture opening  35  to engage the proximal portion of suture material  36  as the material is looped back distally during firing. In addition to spaced indentations, other types of sculpted surface areas may also be utilized on the outer circumference of inner locking member  26  for engaging suture material  36  during firing, without departing from the scope of the invention. A pair of positional stops  41  are located on opposite sides of inner locking member  26  adjacent to suture opening  35 . Positional stops  41  are shaped with a ramped proximal side  43  and a squared off distal end  45 . The ramped proximal side  43  enables an outer locking member, which will be described below, to pass distally over stops  41  during firing to engage inner locking member  26 . Once the outer locking member passes over positional stops  41  and onto the distal end of inner locking member  26 , the squared off distal end  45  of the stops blocks the outer locking member from moving proximally and disengaging from the knotting element. 
         [0036]    As shown in  FIGS. 2 and 3 , the proximal end of launching member  24  comprises an anchor section or knot tying element  40 . Anchor section  40  comprises a longitudinally-extending, cylindrical shaft with a rounded proximal end. Anchor section  40  connects launching member  24  to a drive cable  42  so that the member may be moved by the cable during firing. A semi-circular cutout or recess  44  is formed in the outer surface of anchor section  40 . Cutout  44  is shaped to engage a mating lip on a drive cable connector, which will be described below, when launching member  24  is inserted into device  20 . 
         [0037]    Between the inner locking member  26  and anchor section  40  of launching member  24 , is a fracture section  32  shown in  FIGS. 2 and 3 . Fracture section  32  comprises an area of reduced diameter along the longitudinal length of launching member  24 . In fracture section  32 , the diameter of launching member  24  is substantially less than the diameter of the remaining length of the member, so as to form a weak point in the member. When pressure is applied to launching member  24  during firing, the reduced diameter in fracture section  32  causes structural failure at this point, thereby separating the distal end of launching member  24 , including inner locking member  26 , from anchor section  40  of the launching member. The particular diameter utilized within fracture section  32  will vary depending upon the diameter of the distal and proximal portions of launching member  24 , as well as the strength of the particular materials used in manufacturing the launching member. The longitudinal length of fracture section  32  is preferably minimized to the shortest length necessary to ensure fracturing. The distal and proximal portions of launching member  24  adjacent to fracture section  32  have a parabolic shape, as indicated by reference numeral  52  in  FIG. 2 , to concentrate the stress on launching member  24  within the fracture section. In the embodiment described above, launching member  24  is formed as a single unit from a biocompatible plastic material such as, for example, polyetheretherketone (PEEK). In addition to PEEK, other biocompatible materials such as, for example, Vectra, may be used to form the launching member. 
         [0038]    A cylindrical outer locking member  64  is disposed about the outer periphery of launching member  24 . As shown in greater detail in  FIGS. 5A and 5B , the inner surface of outer locking member  64  is separated into a first inner diameter  66  and a second, smaller inner diameter  70 . The distal opening to first inner diameter  66  is tapered, as shown at  72 , to provide a lead-in guide for inner locking member  26 . The proximal end of first inner diameter  66  is also angled inwardly towards second inner diameter  70  to form an end stop  74 . A detent  76  is formed on the outer circumference of launching member  24 , as shown in  FIGS. 2 and 3 , for retaining outer locking member  64  in an unlocked position while suture locking device  20  is advanced to the suture site. In an unfired position, end stop  74  rests in contact with detent  76  on launching member  24  to position outer locking member  64  proximal of inner locking member  26  and suture opening  35 . The outer diameter of inner locking member  26 , including indentations  39 , is greater than second inner diameter  70  of outer locking member  64 . This diameter differential between inner and outer locking members  26 ,  64  forms a positional stop, causing inner locking member  26  to contact end stop  74  as launching member  24  moves proximally during firing. The contact between inner locking member  26  and end stop  74  terminates proximal movement of the inner locking member, and prevents the inner locking member from traveling completely through outer locking member  64 . 
         [0039]    First inner diameter  66  is selected to provide a clearance between the inner surface of outer locking member  64  and the outer surface of inner locking member  26  that is sufficient to deform suture material  36  between the opposing surfaces when the inner and outer locking members are joined into a knotting element. Additionally, indentations  39  along the outer surface of inner locking member  26  increase the contact area between suture material  36  and the inner locking member. Second inner diameter  70  extends proximally from end stop  74  to the proximal end of outer locking member  64 . In an unlocked position, second inner diameter  70  surrounds launching member  24  proximal of detent  76 . The reduced size of second inner diameter  70  prevents outer locking member  64  from moving distally along launching member  24  and prematurely locking prior to firing. The outer diameter  78  of outer locking member  64  is sized to allow the member and suture material to concurrently pass through a 2.8 mm working channel of an endoscope. 
         [0040]    As shown in  FIG. 6 , anchor section  40  of launching member  24  is inserted into a cylindrically-shaped adaptor  80 . The distal end of adaptor  80  is open or at least partially cut away, as indicated by reference numeral  79 , to accommodate anchor section  40  when launching member  24  is loaded into the adaptor. A semi-circular lip  83  protrudes into the inner diameter of adaptor  80 . Lip  83  engages cutout  44  of launching member  24  to operatively connect the launching member and adaptor  80 . As shown in  FIGS. 2 and 3 , a cable connector  81  is disposed in the proximal end of adaptor  80  for connecting drive cable  42  to the adaptor and, correspondingly, to launching member  24 . Drive cable  42  includes a coined distal end  82  for attachment within cable connector  81 . The larger size of coined end  82  locks the cable within connector  81 . A pin  88  is inserted through adaptor  80  and connector  81  via pairs of openings  85 ,  87 . Openings  85 ,  87  extend through the connector and adaptor respectively in a direction perpendicular to the axial length of device  20 . Pin  88  retains cable connector  81  within adaptor  80 . 
         [0041]    A cylindrical housing  84  extends proximally along the device axis from outer locking member  64 . Housing  84  includes an open, distal end  86  that surrounds the outer circumference of adaptor  80 . The inner diameter of open distal end  86  is selected to enable adaptor  80  to move freely in an axial direction within housing  84 . The axial length of housing  84  is sufficient to allow adaptor  80  to pull a substantial length of launching member  24  into the housing during firing, thereby assuring that the tension applied to drive cable  42  is fully transferred to fracture section  32 . The distal end of housing  84  also serves as a proximal end stop  90  for outer locking member  64 . End stop  90  maintains outer locking member  64  in a fixed position during firing, thereby enabling inner locking member  26  to travel proximally into the first inner diameter  66  of the outer locking member. As inner locking member  26  travels into first inner diameter  66 , outer locking member  64  plastically deforms around the inner locking member due to the limited clearance between the outer surface of the inner locking member and the inner surface of the outer locking member. 
         [0042]    In an exemplary embodiment, the clearance between the opposing surfaces of the inner and outer locking members  26 ,  64  is approximately 0.1 mm for a monofilament suture material having a diameter of 0.2 mm. This clearance within the locked knotting element is sufficient to deform the suture material between the opposing locked surfaces, as well as deform outer locking member  64  about the exterior of inner locking member  26 . The clearance between the inner and outer locking members may vary, however, depending upon the type of suture material being joined. Preferably, the clearance between the opposing locked surfaces is less than the diameter of the suture material, thereby assuring deformation of the material and increased friction between the suture material and mating surfaces of the knotting element. 
         [0043]    As shown in  FIGS. 1 and 3 , housing  84  includes a pair of longitudinal side slots  96  through the outer diameter of the housing. The ends of pin  88  extend beyond adaptor openings  87  into side slots  96 . Each side slot  96  aligns with one of the exposed ends of pin  88  so that the pin ends ride along the slots during firing. The movement of pin  88  through slots  96  properly orients adaptor  80  to prevent drive cable  42  from rotating within housing  84  as the cable moves linearly during firing. Spaced around housing  84  from side slots  96  are a pair of holes  98  that provide a passageway for suture material  36  to pass through housing  84  for in-line tensioning and cutting, as will be described in more detail below. 
         [0044]    To load launching member  24  into device  20 , adaptor  80  and cable connector  81  are first advanced distally until the partially open end of adaptor  80  extends beyond the open distal end of housing  84 , as shown in  FIG. 7A . Launching member  24  with outer locking member  64  loaded thereon (referred to herein as the knot tying element), is then inserted into the distal end of adaptor  80 , by angling anchor section  40  of the launching member into adaptor opening  79 , as shown in  FIG. 7B . As anchor section  40  is angled into adaptor  80 , cutout  44  of the anchor section moves into position above lip  83  of the adaptor. Once cutout  44  is in position over lip  83 , launching member  24  is lowered down into adaptor  80  until the launching member is axially aligned with adaptor  80  and housing  84 , as shown in  FIG. 7C . Once launching member  24  is lowered, lip  83  engages cutout  44  to enable adaptor  80  to pull the launching member proximally when tension is applied to the adaptor through drive cable  42 . 
         [0045]      FIGS. 8A and 8B  illustrate an alternative embodiment for attaching drive cable  42  to a launching member. In this embodiment, the launching member and adaptor are both modified to form a reloadable connection therebetween. As shown in  FIG. 8A , a modified launching member  124  includes a plurality of bayonets  100 . Bayonets  100  extend from a post  102  at the proximal end of launching member  124 . Drive cable  42  is in turn securely attached, such as by welding or coining, to a ferrule  104 , having a plurality of circumferential openings  106 . Ferrule  104  is attached by a pin  110  to the open distal end of a modified housing  184 . To attach drive cable  42  to launching member  124 , ferrule  104  is threaded over the proximal end of the launching member such that openings  106  pass between bayonets  100 . To lock ferrule  104  to launching member  124 , the launching member is rotated relative to the ferrule until bayonets  100  reach openings  106 . As bayonets  100  reach openings  106 , the bayonets snap through the openings, locking launching member  124  to ferrule  104 , as shown in  FIG. 8B . As drive cable  42  is pulled proximally during firing, the interaction between bayonets  100  and openings  106  pulls launching member  124  and, thus, inner locking member  26 , proximally into outer locking member  64 . To release launching member  124  from ferrule  104 , the launching member and modified housing  184  (with the attached ferrule) are twisted in opposite directions, causing bayonets  100  to disengage from openings  106 . Once bayonets  100  are disengaged, ferrule  104  with attached drive cable  42  may be removed from launching member  124  and reattached to a new launching member by inserting ferrule  104  over the proximal end of the new launching member and twisting the bayonets into openings  106 . 
         [0046]    Returning now to  FIG. 2 , a catheter  130  such as, for example, a Bowden cable, is attached to the proximal end of adaptor  84 . The inner diameter of the open proximal end of adaptor  84  may be sized to permit a light interference fit with catheter  130 , to enable the adaptor and remaining aspects of suture locking device  20  to be detached from the catheter. Alternatively, suture locking device  20  may be permanently joined to catheter  130  at the open proximal end of adaptor  84 . 
         [0047]      FIG. 9  illustrates the proximal end of catheter  130  and an exemplary handle  132  for deploying a knotting element from suture locking device  20 . Handle  132  is attached at the proximal end of drive cable  42  for applying tension to the cable. Handle  132  comprises a longitudinal body portion  134 , as well as a grip portion  136  for engaging the surgeon&#39;s fingers during operation of device  20 . A thumb guide  144  is located at the proximal end of handle  132 . As shown in greater detail in  FIG. 10 , the distal end of handle  132  includes an outer clamp  150  having a center bore for passage of catheter  130 . A ring  146  is welded to the proximal end of catheter  130  and retained between clamp  150  and handle body  134  to secure the coil. Drive cable  42  extends proximally beyond clamp  150  and catheter  130  into a center bore  154  of handle body  134 . A retaining member  156  is longitudinally disposed in bore  154  of handle body  134 . Grip  136  is attached to retaining member  156  to move the retaining member within handle body  134  in response to pressure applied to the grip by the surgeon. 
         [0048]    Drive cable  42  extends into a center bore within retaining member  156 . The proximal end of drive cable  42  is secured within retaining member  156  by an attachment mechanism, such as, for example, a piece of metal tubing crimped to the end of the cable. Drive cable  42  is locked within retaining member  156  so as to move with the retaining member along the longitudinal axis of handle body  134 . A resilient member  158  extends about drive cable  42  between the proximal end of handle body  134  and retaining member  156 . Resilient member  158  serves to bias cable connector  81  into a proximal position within adaptor  80 . An attachment mechanism  162  is lodged in the proximal end of handle body  134  to attach thumb guide  144  to the handle body, and to allow for rotation of the guide relative to the handle body. Tension is applied to drive cable  42  by pulling proximally on grip  136 . As grip  136  moves proximally, retaining member  156  moves proximally within bore  154  of handle body  134 , due to the connection between the grip and retaining member. As retaining member  156  moves proximally, the length of drive cable  42  is pulled proximally, increasing the tension on the cable. The increased tension on drive cable  42  is transferred to launching member  24  via the interconnection between cable connector  81 , adaptor  80 , and launching member  24 . Handle body bore  154  is sized to allow drive cable  42  to be pulled a sufficient distance to pull inner locking member  26  into outer locking member  64 , as well as separate the knotting element from launching member  24 . 
         [0049]    To deploy a knotting element from suture locking device  20 , the device is introduced into the working channel of an externalized endoscope in an initial, unfired position. Suture locking device  20  is advanced through the working channel of the endoscope until inner and outer locking members  26 ,  64  are visible beyond the distal end of the scope. Suture material  36  that has been externalized out the patient&#39;s mouth (or other orifice or incision) is threaded into the distal end of inner locking member  26 . The suture material is passed through bore  30  of inner locking member  26  and out through opening  35  of launching member  24 . Upon exiting launching member  24 , the ends of suture material  36  are passed through holes  98  in housing  84  and retrieved by the surgeon. The threaded path of suture material  36  is shown in  FIG. 11 . 
         [0050]    Following threading of suture material  36  into device  20 , the surgeon reintroduces the endoscope into the patient, and advances the scope to the suture site using the suture strands as a guide. In-line tension is maintained on suture material  36  while device  20  is passed towards the suture site by holding the externalized ends of the suture material. Once suture locking device  20  is in position at the suture site, tension is applied to suture material  36 , as well as to handle  132 , to fire the device. As grip  136  is drawn proximally, drive cable  42  is pulled proximally through handle  132 , catheter  130  and housing  84 . The movement of drive cable  42  applies tension to adaptor  80 , which in turn pulls launching member  24  proximally due to the interaction between cut-out  44  and lip  83 . As launching member  24  moves proximally along the device axis, inner locking member  26  is drawn into first inner diameter  66  of outer locking member  64 , as shown in  FIG. 12 . This interaction between inner and outer locking members  26 ,  64  loops suture material  36  back in a distal direction, and holds the suture material tight, preventing the loss of tension. 
         [0051]    As pressure continues to be applied to drive cable  42  by handle  132 , inner locking member  26  is pulled further within outer locking member  64 , causing the outer locking member to plastically deform about the inner locking member due to the small tolerance between the opposing surfaces of the locking members. As inner locking member  26  is pulled within outer locking member  64 , suture material  36 , which extends from the proximal end of inner member bore  30 , is trapped between the outer diameter of the inner locking member and the first inner diameter  66  of the outer locking member, as shown in  FIG. 13 . Due to the limited clearance between the inner and outer locking member surfaces, suture material  36  is deformed therebetween. The uneven outer surface of inner locking member  26  increases the friction between suture material  36  and locking members  26 ,  64 . Additionally, as suture material  36  is tensioned between inner and outer locking members  26 ,  64 , flange  31  creates a right angle bend in the material, further increasing the strength of the suture lock within the knotting element. 
         [0052]    As outer locking member  64  plastically deforms about inner locking member  26 , launching member  24  and adaptor  80  move proximally within housing  84 , with the outer ends of pin  88  moving through side slots  96 . As adaptor  80  moves into the proximal end of housing  84 , the proximal edge of the adaptor contacts the portion of suture material  36  extending through the housing between holes  98 . The contact between the edge of the advancing adaptor  80  and suture material  36  severs the suture material within housing  84 .  FIG. 14  shows the distal separated end of suture material  36  after the proximal edge of adaptor  80  has moved proximally beyond holes  98  and completely severed the suture material. 
         [0053]    After severing, the distal end of suture material  36  is locked between inner and outer locking members  26 ,  64 , while the proximal portion of the suture material extends from a hole  98  of housing  84 . As tension continues to be applied to drive cable  42  by way of handle  132 , inner locking member  26  is prevented from further proximal movement within outer locking member  64  by end stop  74 . Likewise, the locked inner and outer locking members  26 ,  64  become seated against end stop  90  of housing  84 , and thereby prevented from further proximal movement. Once inner and outer locking members  26 ,  64  have reached the respective proximal stop positions, the further application of tension to launching member  24  via drive cable  42  generates a material failure or break at fracture section  32  of the launching member. The breaking tension of fracture section  32  is greater than the force required to plastically deform outer locking member  64  over inner locking member  26 . The difference in tension force assures that inner and outer locking members  26 ,  64  are joined in the knotting element prior to detachment of the inner locking member from the remaining portion of launching member  24 . As launching member  24  breaks apart at fracture section  32 , the locked inner and outer members  26 ,  64  are detached from launching member  24  to form a separate knotting element  170 , shown in  FIG. 14 . In the knotting element  170 , flange  31  and positional stops  41  prevent outer locking member  64  from moving relative to inner locking member  26 . Accordingly, inner and outer locking members  26 ,  64  remain fixed in position within the body with suture material  36  deformed therebetween. 
         [0054]    After separating from inner locking member  26 , the remaining portion of launching member  24  is propelled proximally until pin  88  contacts the proximal end of side slots  96 , thereby stopping further proximal movement of the launching member. After firing, adaptor  80  and the remaining portion of launching member  24 , shown in  FIG. 14 , are removed from the body through the endoscope, leaving knotting element  170  at the suture site. After the remaining portions of device  20  have been removed from the body, the device may be reloaded with a new launching member, as described above, and the firing process repeated, to lock additional pieces of suture material. 
         [0055]    While preferred embodiments of the present invention have been shown and described herein, it will be obvious to those skilled in the art that such embodiments are provided by way of example only. Numerous variations, changes, and substitutions will now occur to those skilled in the art without departing from the spirit and scope of the appended claims.