Abstract:
Sutures can be placed in difficult to access areas of the human body with devices, and related methods, utilizing a suture carrier with a sharpened tip and a notch for holding a formed suture tip. The devices and methods can be used in conjunction with both endosurgical and traditional open surgery.

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
   This application is a continuation of copending application U.S. Ser. No. 09/861,826, filed on May 21, 2001. 

   TECHNICAL FIELD 
   The invention relates to devices and methods for placing sutures. 
   BACKGROUND INFORMATION 
   Suturing of body tissue is a time consuming aspect of many surgical procedures. For many surgical procedures, it is necessary to make a large opening in the human body to expose the area that requires surgical repair. There are instruments available that allow for viewing of certain areas of the human body through a small puncture wound without exposing the entire body cavity. These instruments, called endoscopes, can be used in conjunction with specialized surgical instruments to detect, diagnose, and repair areas of the body that previously required open surgery to access. 
   Some surgical instruments used in endoscopic procedures are limited by the manner in which they access the areas of the human body in need of repair. In particular, the instruments may not be able to access tissue or organs located deep within the body or that are in some way obstructed. Also, many of the instruments are limited by the way they grasp tissue, apply a suture, or recapture the needle and suture. In addition, the needle can become separated from the needle-driving device and lost within a patient. Furthermore, many of the instruments are complicated and expensive to use due to the numerous parts and/or subassemblies required to make them function properly. 
   SUMMARY OF THE INVENTION 
   The suture passer of the present invention eliminates the need for a preassembled needle and suture and eliminates the possibility of needle loss during suturing. This is accomplished by eliminating the use of a loose needle or any needle at all. Specifically, the suture passer uses a suture with a formed tip that engages a suture carrier. The suture carrier is coupled to the suture passer and has a sharpened end for piercing tissue. The suture carrier also has a notch for carrying the formed tip of the suture. When the device is actuated, the suture carrier pierces the tissue and carries the formed tip through the tissue and into a formed tip catch. The suture carrier is then retracted leaving the suture intact. 
   In one aspect, the invention relates to a suturing instrument. The suturing instrument includes an elongate body member, a suture deployment system disposed at a distal portion of the elongate body member, and a catch to receive and retain a formed suture tip. The suture deployment system includes a suture carrier having a sharpened distal end for tissue penetration and a notch for holding the formed suture tip. 
   In some embodiments, the suturing instrument may include a deployment controller having a proximal end and a distal end. The deployment controller extends substantially along a longitudinal axis of the elongate body member to the distal portion of the elongate body member, where the distal end of the deployment controller is coupled to the suture carrier and moves the suture carrier between a retracted position and a deployed position. The proximal end of the deployment controller may be coupled to an actuator. In some embodiments, the deployment controller guides the suture carrier along a path that includes a proximal curved path segment such that the suture carrier initially travels away from the elongate body member and then towards the elongate body member. 
   In another aspect, the invention relates to a suturing instrument including a suture carrier and a body member defining a suture exit port and a suture carrier channel. The suture carrier includes a sharpened distal end for tissue penetration and a notch for holding a formed suture tip. The suture carrier is movably positioned in the suture carrier channel between a retracted position within an interior region of the body member and a deployed position exterior to the body member. The suture carrier is configured within the suture carrier channel such that the suture carrier exits the interior region of the body member through the suture exit port. 
   In yet another aspect, the invention relates to a suturing instrument including an elongate body member having a longitudinal axis and a distal tip suture deployment assembly joined with a distal end of the elongate body member such that the distal tip assembly is free to rotate axially about the longitudinal axis of the elongate body member. The distal tip suture deployment assembly includes a suture exit port and a curved suture carrier channel formed in the distal tip suture deployment assembly, a curved suture carrier movably positioned in the curved suture carrier channel, a suture with a formed tip coupled to the suture carrier, and a deployment controller including a proximal end and a distal end. The deployment controller extends substantially along the longitudinal axis of the elongate body member to the distal end of the elongate body member, where the distal end of the deployment controller is coupled to the distal tip suture deployment assembly and moves the curved suture carrier through the curved suture carrier channel as the deployment controller moves between a retracted position and a deployed position. Additionally, the proximal end of the deployment controller may be coupled to an actuator. 
   In still another aspect, the invention relates to a suturing instrument including a body member defining an exit port and a carrier channel, a carrier movably positioned in the carrier channel, and a surgical needle permanently fixed on a distal end of the carrier. The carrier has a retracted position within an interior region of the body member and a deployed position exterior to the body member. The carrier is configured within the carrier channel such that the carrier exits the interior region of the body member through the exit port. The permanently fixed needle may include a notch for holding a formed suture tip. In addition, the exit port, suture carrier channel, and suture carrier can be located in a distal tip assembly coupled to the body member, and the distal tip assembly can be coupled to the body member such that the distal tip assembly is free to rotate axially about a longitudinal axis of the body member. 
   Various embodiments according to any of the foregoing aspects of the invention can include the following features. A suture can include a formed tip, which may be permanently fixed to an end of the suture. The formed tip of the suture can insert into the suture carrier notch. Also, the formed tip can be plastic, metal, or polymer compound. In addition, the suturing instrument can include a catch to receive and retain the formed suture tip, where the catch is positioned on the body member such that a distal segment of the suture carrier&#39;s path is intercepted by the catch. Additionally, the suturing instrument may include a second suture carrier and a second exit port. Further, the deployment controller may be coupled to the suture carrier with a flexible driver member. The flexible driver member may be manufactured of an alloy that includes at least or exclusively nickel and titanium. 
   An additional aspect of the invention relates to a method for placing a suture in tissue. In accordance with the method, inserting a suturing instrument enclosing a suture carrier having a sharpened end for tissue penetration and a notch for holding a formed suture tip, deploying the suture carrier out of the suturing instrument through an exit port such that the suture carrier exits an interior region of the suturing instrument through the exit port along a path which approaches being substantially tangential to an outer surface of the suturing instrument surrounding the exit port, and capturing a suture carried by the suture carrier in a catch that receives and retains the formed suture tip. The suture carrier is movably positioned within a suture carrier channel adjacent the tissue to be sutured. 
   These and other objects, along with advantages and features of the present invention herein disclosed, will become apparent through reference to the following description, the accompanying drawings, and the claims. Furthermore, it is to be understood that the features of the various embodiments described herein are not mutually exclusive and can exist in various combinations and permutations. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In the drawings, like reference characters generally refer to the same parts throughout the different views. Also, the drawings are not necessarily to scale, emphasis instead generally being placed upon illustrating the principles of the invention. In the following description, various embodiments of the present invention are described with reference to the following drawings. 
       FIGS. 1A-1H  are cutaway views illustrating the general structure and operation of one embodiment of the present invention. 
       FIGS. 2A-2D  and  2 F are perspective views of various embodiments of sutures and formed suture tips. 
       FIG. 2E  is a cross-sectional view of one embodiment of a suture and formed tip. 
       FIGS. 2G and 2H  are end views of the embodiment of a suture and formed tip shown in  FIG. 2F . 
       FIG. 3A  is a partial-cutaway view of a suture carrier. 
       FIG. 3B  is an enlarged perspective view of the suture carrier of  FIG. 3 . 
       FIG. 4  is a perspective view of a catch and a suture with a formed suture tip. 
       FIG. 5  is a perspective view of an alternate catch mechanism with a suture carrier. 
       FIGS. 6A and 6B  are partial cutaway views illustrating the general structure and operation of one embodiment of a suture delivery and capture system. 
       FIGS. 6C and 6D  are partial cutaway views illustrating the general structure and operation of an alternate embodiment of a suture delivery and capture system. 
       FIG. 7  is a partial side view taken along line  7 - 7  of  FIG. 6A  and illustrating the formed suture tip catch. 
       FIG. 8  is a cross-sectional view taken along line  8 - 8  of  FIG. 7 . 
       FIG. 9A  is an exploded illustrating the general structure of an alternate embodiment of the suture carrier and guide track. 
       FIG. 9B  is a perspective view illustrating the general structure of an alternate embodiment of the suture carrier of  FIG. 9A . 
       FIG. 10  is a cross-sectional view illustrating the relationship between the suture carrier and guide track. 
       FIGS. 11A and 11B  are cross-sectional views of two alternate designs of the suture carrier taken along line  11 - 11  of  FIG. 9A . 
       FIG. 12  is a cross-sectional view of the suture carrier and guide track taken along line  12 - 12  of  FIG. 10 . 
       FIG. 13  is a cross-sectional view of the suture carrier and guide track taken along line  13 - 13  of  FIG. 10 . 
       FIG. 14  is an elevation of another embodiment of the present invention. 
       FIG. 15  is a cutaway view illustrating the general internal structure of the embodiment shown in  FIG. 14 . 
       FIG. 16  is a cutaway view of the head of the embodiment shown in  FIGS. 14 and 15 . 
       FIGS. 17A-17D  are cutaway views illustrating the operation of the embodiment shown in  FIGS. 14-16 . 
       FIGS. 18A-18B  are partial-cutaway views of the distal tip of one embodiment of a suturing device and illustrating the general structure and operation of the axial articulation of the suture driver head. 
       FIGS. 19A-19C  are perspective views of one embodiment of a suturing instrument of the invention featuring an elbow-shaped, elongated body member with a rotatable head shown in various rotated positions. 
       FIGS. 19D-19F  are partial-cutaway views illustrating some details of the rotatable head shown in  FIGS. 19A-19C  and featuring a suture carrier, a catch, and engaging elements. 
   

   DESCRIPTION 
   Embodiments of the present invention are described below. It is, however, expressly noted that the present invention is not limited to these embodiments, but rather the intention is that modifications that are apparent to the person skilled in the art are also included. 
     FIGS. 1A-1H  illustrate the general structure and operation of one embodiment of the present invention. A device  2  according to the present invention incorporates a length of suture material  4  with a formed tip  6  on each end. Suture carriers  10  hold the formed tips  6 . The suture carriers  10  and formed tips  6  are deployable out of a housing  12  and into tissue surrounding a puncture wound  14 . Deployment is via an actuator, such as a plunger  3 , coupled to a pair of rigid driving members  5 , which are suitably attached to the suture carriers  10 . In this disclosed embodiment, the plunger  3  is pushed, simultaneously driving the suture carriers  10  and formed tips  6  into a catch mechanism  16 . The suture carriers  10  are then retracted back into the housing  12 . The housing  12  (now containing only the suture carriers  10  without the formed tips  6 ) and the catch mechanism  16  with the captured formed tips  6  are retracted as shown in  FIGS. 1G and 1H . With a loop of suture  4  having thus been placed in the tissue surrounding the puncture wound  14 , the suture device  2  is removed from the wound  14 , thereby pulling the ends of the suture  4  with it ( FIG. 1H ). Closure of the puncture wound  14  is accomplished by cutting the suture  4  to disconnect the formed tips  6  from the installed suture  4 , tying a knot with the now-free ends of the installed suture  4 , and pushing into the wound  14  the knot and any suture  4  extending out of the wound  14 . Superficial closure is then performed by normal means according to a surgeon&#39;s preference. 
   The suture carrier path shown in  FIGS. 1A-1H  is generally circular; however, it is contemplated that the above embodiment may be modified to include suture carrier paths other than circular, such as helical, elliptical, or straight, by modification of the suture carriers and/or the suture carrier guides defined by the housing  12 . It is also possible to adapt the above configuration to allow each of the suture carriers to be actuated and driven independently by dividing the deployment controls and the suture carrier drivers into separate left and right hand members. Further, it is possible to utilize a tool that uses only a single suture carrier and guides the carrier through both sides of the wound as opposed to the double suture carrier configuration described above. 
   Referring to  FIG. 2A , a formed tip  234  (such as the formed tip  6  described above and the one described hereinafter) comprises a body  236  having a shoulder  238 . The shoulder  238  is the rear surface of the formed tip body  236  that engages a catch. A length of suture material  242  is inserted into a hole  244  located on the shoulder  238  and attached to the formed tip  234  thereby. The suturing material  242  is attached to the body  236  by any suitable means, such as crimping or adhesive bonding. The rectangular shaped body  236  is merely illustrative, and the shape may be varied to fit a particular application. For example, a simple elongated cylinder or a triangular block may be used, as shown in  FIGS. 2B-2E . The formed tip  234  can be manufactured from a plastic, metal, or polymer compound and can be formed by, for example, extrusion, molding, or machining. Furthermore, the type of material(s) used to form the suture is not critical to the present invention, as long as the material(s) used is/are biocompatible. The formed tip  234  of the present invention may be used with any type or size (length, cross-sectional shape) of suture material. The surgeon will select the length, diameter, and characteristics of the suture to suit a particular application. 
   Various possible formed tips according to the invention are now described with reference to  FIGS. 2B-2H . 
   In  FIG. 2B , the suture  242  is shown attached to an elongated cylindrically-shaped body  235 , which may illustratively be somewhat rigid, at least as compared to the suture  242 , to facilitate capture by a catch. As illustrated in  FIG. 2C , an end portion of the suture  242  may be molded or otherwise formed within the body  235  of the formed tip. 
   In  FIGS. 2D and 2E , the body  237  has a generally triangular cross-sectional shape and is shown attached to the suture  242 . It will be appreciated that the suture  242  may be inserted into a mold in which a plastic or plastic-like material of the body  237  is injected. Alternatively, the suture  242  may be held within a hole  245  within the body  237  by adhesive bonding. 
     FIGS. 2F-2H  show how a body  239  may be clamped downwardly on a suture  242  and welded or otherwise pressure formed and closed to capture the suture  242 . The body  239  is an elongated member having a C-shaped cross-section, as shown in  FIG. 2F , to receive the suture  242 . The body  239  may have a plurality of ridges  241  as shown to grip the suture  242  when the C-shaped body  239  is clamped with forces F as shown in  FIG. 2G  to produce the cross sectional shape shown in  FIG. 2H . Techniques for welding or joining plastic by the application of pressure and energy to capture another material, such as a suture, are well known. 
   Referring now to  FIG. 3A , a suture carrier  246  (such as the suture carriers described above and the one described hereinafter) comprises a body  248  defining a lumen  259 , a notch  250  to receive a formed tip  234 , and a sharpened end  252  for tissue penetration. Forming or machining may be used to fabricate the sharpened end  252 . The lumen  259  is in communication with the notch  250  at one end and with an aperture  258  at the other end. The notch  250  is sized and shaped to releasably engage the formed tip  234 . A length of suture material  242  attached to the formed suture tip  234  is inserted into the notch  250 , through the lumen  259 , and out the aperture  258 . The attached formed tip  234  is then releasably engaged with the notch  250 . Alternatively, the suture carrier  246  can be a solid piece with the suture  242  disposed in a groove in the outer surface of the suture carrier  246 . 
     FIG. 3B  depicts an enlarged view of the tip of the suture carrier  246 . The formed tip  234  is releasably engaged with the notch  250  so that the body  236  protrudes slightly from the notch  250 . The rear surface of the body  236 , which forms the shoulder  238 , faces away from the sharpened tip  252 . The formed tip  234  is engaged with the notch  250  such that the body  234  is held in place by frictional forces when the suture carrier  246  is extended forward. The body  236  is released from the notch  250  when the suture carrier  246  is retracted from a catch. The shoulder  238  is dimensioned so as to be retained by the catch when the suture carrier  246  exits the catch. The interaction of the suture carrier  246  and various catches is described in greater detail with respect to  FIGS. 4 and 5 . 
     FIGS. 4 and 5  depict alternate catches and illustrate their operation. Referring to  FIG. 4 , the catch  260  includes openings  262  defined by successive ribs  264 . The catch  260  receives a suture carrier  246  (not shown) and a suture  242  with a formed tip  234  through opening  262 , the ribs  264  deflect slightly to allow the suture carrier  246  and formed tip  236  to pass through. After the formed tip shoulder  238  has passed the ribs  264  and the suture carrier  246  has been withdrawn, thereby releasing the formed tip  234 , the ribs  264  spring back to their original position defining the openings  262 . The openings  262  are chosen to be smaller in dimension than the formed tip shoulder  238 . This causes the catch  260  to retain the formed tip  234 , because due to the flat rear surface of the shoulder  238 , the formed tip  236  cannot pass back through an opening  262 . When it is necessary to remove the formed tip  234  from the catch  260 , it may be moved toward an enlarged portion  265  of opening  262 . The enlarged portion  265  is sized to allow the formed tip shoulder  238  to pass through without resistance. The catch  260  is preferably constructed of thin stainless steel of high temper, such as ANSI 301 full hard. The catch  260  may be fabricated by means of stamping, laser machining, or chemical etching. 
   Referring now to  FIG. 5 , a catch  266  includes a frame  268  to which is attached a woven mesh  270 . Threads  272  creating the woven mesh  270  may be nylon, polyester, or the like woven in a common over/under pattern. The weaving of the threads  272  creates windows  274  in the mesh through which a suture carrier  246  may be passed. The suture carrier  246  is constructed such that the shoulder  238  of the formed tip  234  is larger than the windows  274 , or conversely, the windows  274  are chosen to be smaller than the shoulder  238 . The sharpened end  252  of the suture carrier  246  pushes the threads  272  aside creating room for the shoulder  238  to pass through the windows  274 . Upon withdrawal of the suture carrier  246 , the threads  272  return to their original positions and the catch  266  retains the formed tip  234  (once again due to the flat rear surface of the shoulder  238 , which is larger than the windows  274 ). 
     FIGS. 6A and 6B  depict one embodiment of a suture carrier and catch system. Referring to  FIG. 6A , an elongate body member  718  is formed of two complementary housing halves  720   a,b . It is to be understood that for clarity only one of the housing halves  720   a  of the elongate body member  718  is shown in  FIGS. 6A and 6B . The housing halves  720   a,b  are configured to create a guided pathway  722  that includes a suture carrier channel  724  and a flexible carrier driver guide track  726 . A suture carrier  728  and flexible carrier driver  730  are joined at an end  732  of the suture carrier  728 . Crimping, welding, adhesive bonding, or various other techniques can accomplish the attachment between the suture carrier  728  and the flexible carrier driver  730  at the end  732 . A formed tip  734  and a length of suture material  742  are attached to the suture carrier  728 . Further incorporated in the housing halves  720  are a pair of catch pockets  746   a,b , which position and retain a catch  748 . Referring to  FIG. 7 , the catch  748  includes openings  750  defined by ribs  752 . The configuration and function of the formed tip catch  748  is similar to that described earlier with respect to  FIG. 4 . When the catch  748  is fabricated by means of chemical etching, the preferred method is to etch from a single side, known in the art as single sided etching. When the catch  748  is etched from a single side, the ribs  752  have a tapered cross-section  753  as shown in  FIG. 8 . The tapered cross section  753  helps to guide the sharpened end of the suture carrier  728  into the catch openings  750 , thereby minimizing the chance of the sharpened end of the suture carrier  728  hitting the top of the ribs  752 . 
   With renewed reference to  FIGS. 6A and 6B , the operation of this embodiment will be described.  FIG. 6A  shows the formed tip  734  loaded into the suture carrier  728 , which is depicted in the retracted position. In this position, the body  718  may be passed through a surgical trocar and into a body cavity for operation of the device. As shown in  FIG. 6B , as the flexible carrier driver  730  is advanced into the suture carrier channel  724 , the suture carrier  728 , holding the formed tip  734  and trailing the suture  742 , is driven in a semi-circular path that intersects the catch  748 . The formed tip  734  is received and retained by the catch  748  in a manner previously described with respect to  FIG. 4 . The flexible carrier driver  730  may be retracted back into the flexible carrier driver guide track  726 , causing the suture carrier  728  to rotate back into the suture carrier channel  724 . The instrument may be removed from the surgical trocar, and the process repeated on the other side of the wound. 
     FIGS. 6C and 6D  depict an alternate suture carrier and catch system. Referring to  FIG. 6C , an elongate body member  770  is comprised of a pair of complementary housing halves  772   a,b . It is to be understood that for clarity only one of the housing halves  772   a  of the body  770  is shown in  FIGS. 6C and 6D . The housing halves  772   a,b  are configured to create a guided pathway  774  that defines a suture carrier channel  776  and a flexible carrier driver guide track  778 . A suture carrier  780  and flexible carrier driver  782  are joined at a saddle  784  of the suture carrier  780 . The saddle  784  comprises a channel, groove, or opening formed in the proximate end of the suture carrier  780  into which the flexible carrier driver  782  may enter. Crimping, welding, adhesive bonding, or various other techniques can accomplish the attachment between the suture carrier  780  and the flexible carrier driver  782  at the saddle  784 . A formed tip  790  and a length of suture material  794  are attached to the suture carrier  780 . Further incorporated in the housing halves  772   a,b  are a pair of catch pockets  798   a,b  that position and retain a catch  800 . The configuration and function of the catch  800  is similar to that described earlier with respect to  FIG. 4 . The suture carrier  780  carries the formed tip  790  of the suture through the tissue and into the catch  800  as previously described. 
   Although the operation of this embodiment is similar to that described in  FIGS. 6A and 6B , there are some differences. Referring back to  FIGS. 6A and 6B , as the suture carrier  728  approaches the end of its stroke, as illustrated in  FIG. 6B , the circumferential length of the suture carrier  728  left inside the suture carrier channel  724  is minimal. This may allow the suture carrier  728  holding the formed tip  734  to drift off of the prescribed arcuate path that terminates in the formed tip catch  748 . This drift may allow the sharpened end of the suture carrier  728  to miss the catch  748 , causing an incomplete suturing cycle. Therefore, it is desirable to increase the circumferential length of the suture carrier left inside the guide track in order to improve the guidance of the suture carrier. 
   Accordingly, the embodiment illustrated in  FIGS. 6C and 6D  equips the suture carrier  780  with the saddle  784 . The saddle  784  allows the flexible carrier driver  782  to exit from the suture carrier  780  at a point along the circumference, rather than at a distal end  804 . This may be seen to increase the overall arc length of the suture carrier  780  when compared with the suture carrier  728  shown in  FIG. 6A . As a result, when the flexible carrier driver  782  is slidably moved in the guided pathway  774 , the suture carrier  780  rotates within the suture carrier channel  776  such that when the formed tip  790  enters the catch  800 , a significantly larger portion of the suture carrier  780  is still captured within the suture carrier channel  776 . This may provide additional guidance to the suture carrier  780  as it penetrates tissue. This geometry may also allow for a longer stroke length and greater tissue bite. 
   Referring to  FIG. 9A , the distal end of an elongate body  858  is comprised of a pair of complementary housing halves  860   a,b . It is to be understood that for clarity only one of the housing halves  860   a  of the body  858  is shown in  FIG. 9A . The housing halves  860   a,b  are configured to create a guided pathway  862  that defines a suture carrier channel  864  and a flexible carrier driver guide track  866 . A suture carrier  868  includes a saddle  872 , to which is attached a carrier bearing  874 . The saddle  872  comprises a channel, groove, or opening formed in the proximate end of the suture carrier  868  into which the flexible carrier driver  870  may enter. 
   The construction of the suture carrier may be best understood by referring to  FIG. 11A , where a cross-sectional view shows the suture carrier  868  and the carrier bearing  874 . The carrier bearing  874  further includes bearing wings  876   a,b . The carrier bearing  874  may be joined by welding, adhesive bonding, or the like to the suture carrier  868 . 
   The suture carrier  868  may also be formed by another method.  FIG. 11B  shows a cross-sectional view of a suture carrier  878  that has been formed out of, for example a 17-4 stainless steel alloy by a process called metal injection molding. This process allows the suture carrier  878  to be formed in a monolithic fashion such that the suture carrier  878 , bearing wings  880   a,b , and saddle are formed as one piece. Other processes such as die casting, investment casting, or powdered metal could also be used to create a monolithic suture carrier  878 . 
   Another embodiment of the suture carrier, indicated generally at  885  in  FIG. 9B , includes a sharpened end  886  at the distal end adapted to penetrate tissue and a groove  887  at the proximal end adapted to contain a flexible suture driver  888  as previously described. A series of pins  889   a,b, c, d  are attached to the sides of the suture carrier  885 . The pins  889   a,b, c, d  are dimensioned to be slidably disposed within the groove  884  in the suture carrier channel  864 , and to provide guidance and stability to the suture carrier  885  in a fashion similar to that described with reference to  FIG. 9A  below. 
   Referring again to  FIG. 9A , the suture carrier  868  and flexible carrier driver  870  are joined as previously described at saddle  872  of the suture carrier  868 , which incorporates bearing wings  876 . The suture carrier  868  has a sharpened distal end  882  adapted to penetrate tissue as previously described in other embodiments. Alternatively, the suture carrier  868  may include an aperture located at its distal end for receiving a surgical needle, the needle being permanently attached to the suture carrier  868 . The needle includes a sharpened distal tip and a notch for holding a formed suture tip. The surgical needle can be permanently attached to the suture carrier  868  by welding, chemical bonding, or similar technique. In this embodiment, the suture carrier guide track  864  further incorporates a groove  884  adapted to receive the bearing wings  876   a,b .  FIG. 12  depicts a detailed cross-sectional view of the groove  884  and the bearing wings  876 .  FIG. 13  depicts a detailed cross-sectional view of the suture carrier guide track  864  and illustrates an area of the suture carrier  868  and of the suture carrier guide track  864  where there are no bearing wings  876 . It should be understood that the cross-section shown in  FIG. 13  of the suture carrier  868  could be of solid material instead of tubular material if the cross-section were illustrating a monolithic part, such as suture carrier  878 . It may also be understood from the foregoing illustrations, that the width and depth of the bearing wings  876   a,b  shown in  FIG. 11A  and the bearing wings  880   a,b  shown in  FIG. 11B  are not to be taken as literal illustrations of the physical dimensions of those features, as the width and depth may be varied in order to achieve more or less guidance and bearing surface area as the designer deems appropriate. 
   The operation of the embodiment described in  FIGS. 9A through 13  is identical to that previously described in  FIGS. 6C and 6D , with the exception that the bearing wings  876   a,b  are adapted to rotationally slide in the grooves  884   a,b  of the housing halves  860   a,b . This provides axial and torsional guidance and resistance to deflection of the suture carrier  868  from the anticipated path. Performance improvements over the embodiment described in  FIGS. 6C and 6D  relate primarily to an increased ability to torque and/or lift the device while the suture carrier is exposed to the tissue to be sutured. 
   The preferred material for the flexible carrier driver  870  is an alloy of nickel and titanium known in the art as nitinol. This material has both austenitic and martensitic forms, and can be alloyed to exhibit properties of both forms as the material moves through a transition temperature that can be varied. The martensitic form of the alloy, when processed into, for example wire, has a lead-solder like consistency and easily deflects plastically to a certain point, beyond which a considerable amount of force is necessary to cause further deflection. This elastic behavior is what allows the material to be both flexible and exhibit high column strength when properly constrained. Thus, the flexible carrier driver  870  is constrained in a track that allows it to be moved axially, but constrains its deflection off-axis. 
   Another embodiment of the invention is shown in  FIGS. 14-18 . This embodiment of the present invention is particularly well suited for, e.g., the fixation of sutures to the Cooper&#39;s ligament during the performance of a Burch bladder neck suspension via a transvaginal approach. As will become apparent, this embodiment includes features for limiting the depth of the sharpened end penetration for placing sutures in, for example, ligaments lying directly on bone, and for accommodating the anatomy of, for example, the female pelvis. 
     FIG. 14  depicts a suturing instrument  300  including a pair of handles  302   a,b , an elongate body  304 , distal tips  306   a,b , and an actuator button  308 .  FIG. 15  depicts the suturing instrument  300 , the handle  302   a , the elongate body  304 , the distal tip  306   a , and the actuator button  308  in cross-section. The actuator button  308  includes a button head  310 , a button shaft  312 , a series of button bearing surfaces  314   a,b, c, d , a button end  316 , and a hole  318 . The button bearing surfaces  314   a,b,c,d  ride along a cylindrical surface  320  that is formed by the inside diameter of the elongate body  304 . A wireform  322  is inserted into the hole  318 , coupling it to the actuator button  308 . A spring  324  encircles the wireform  322 , abuts the button end  316 , and is compressed between the button end  316  and a spring washer  326 . The spring washer  326  is seated upon a center tube  328 . The center tube  328  is housed by the cylindrical surface  320  and is constrained at the distal end by the distal tip  306 . A pusher wire  330  is attached to the wireform  322  by means of a weld, a coupling, adhesive, or other means, and is slidably disposed within a proximal guidance sleeve  332  and a distal guidance sleeve  334 , said sleeves  332 ,  334  being disposed within a cylindrical surface  336  formed by the inside diameter of the center tube  328 . 
   The pusher wire  330  is preferably constructed of nitinol wire, so chosen as previously discussed for its combination of properties that allow for bendability and high column strength when constrained. The constraints in this construction are provided by the proximal guidance sleeve  332  and the distal guidance sleeve  334 . 
     FIG. 16  depicts the distal end of the suturing device  300 . For the purposes of clarity, only one of the distal tips  306   a  is shown and cross-sectional representations of the center tube  328 , the distal guide tube  334 , and the elongate outer tube  304  are shown. The pusher wire  330  is attached by welding or other means to a coupling  338 , which is slidably disposed within a track  340 . The coupling  338  is also attached to a carrier wire  342 , which by virtue of its attachment to the coupling  338 , is also slidably disposed within the track  340 . The carrier wire  342  is attached to a suture carrier  344  by welding or other means. The carrier  344  is rotatably and slidably disposed within a suture carrier channel  346  molded into the distal tip  306 . The relationship between the carrier wire  342 , the carrier  344 , and the channel  346  is similar to that previously described in  FIGS. 9-13 . The coupling  338  abuts a backstop washer  348  that is slidably disposed about the pusher wire  330 , and constrained within a pocket  350 . The pocket  350  includes a back wall  352 , against which the backstop washer  348  rests. 
   The track  340  terminates distally in a pocket  354  that includes a wall  356 . A downstop washer  358  is slidably disposed about the carrier wire  342  and constrained within the pocket  354 . Positioned at the terminus of the path of the carrier  344  is a catch  360  that is held distally in a pocket  362  and proximally in a pocket  364 . The catch  360  is similar in construction and function to the catch described with respect to  FIGS. 4 ,  7 , and  8 . The distal tips  306   a,b  are held together by rivets placed in rivet holes  366   a,b,c,d  and by tip shafts  368   a,b  being inserted into the cylindrical surface  320 , which is the inside diameter of the elongate body  304 . A depression  370  in the elongate body  304  may be formed by mechanical means such as striking with a pin or forming with a die. The depression  370  is engaged in a rotation pocket  372   a,b  that is formed as a feature of the distal tips  306   a,b , and will be further described with respect to  FIGS. 18A-18B . 
     FIGS. 17A-17D  depict a sequence of operation of the suturing instrument shown in  FIGS. 14-16 . Although this description relates to a specific application, i.e., the performance of a Modified Burch bladder neck suspension via a transvaginal approach, it is to be understood that the principles and construction herein described may be applied to other areas of the human body, and for other procedures requiring suturing body structures, such as ligaments that are in direct communication with bone.  FIG. 17A  depicts a cross-sectional view of the distal tip of the suturing device  300 . The suturing device  300  is shown with a suture  374  attached to a suture formed tip  376  in a manner similar to that described with respect to  FIG. 2  and is shown loaded into the suture carrier  344  in preparation for actuation. The suturing device  300  has been placed against a ligament  378  that lies directly on a bone  380 . Referring to  FIGS. 15 and 17A , it may be seen that the pusher wire  330  is held in tension by the spring  324 , as the coupling  338  shown in  FIG. 17A  abuts the backstop washer  348  that is held against the back wall  352 , positioning the suture carrier  344  in its retracted position. 
   As those skilled in the art will appreciate, it can be quite difficult to drive a suture through a ligament that lies directly on bone, as the bone&#39;s density typically does not allow a suture needle to penetrate it. Thus a skimming path should be taken to avoid hitting bone, but ensuring good penetration of the ligament and a subsequent “good bite” of tissue. In the case of the Cooper&#39;s ligament that is the focus of the anterior fixation point for the Modified Burch bladder neck suspension procedure, the difficulty in placing those sutures is directly attributable to the ligament lying on the bone and the problems with exposure of the ligament to the surgeon. 
   Again referring to  FIG. 15 , and now  FIG. 17B , the actuator button  308  is depressed by pushing on button head  310 , which via attachment to the wireform  322  is attached to pusher wire  330 , which moves coupling  338  along track  340  while concomitantly moving the carrier wire  342 , which slidably and rotatably moves the suture carrier  344  in the channel  346  and drives the sharpened end of the suture carrier  344  into the ligament  378 . The suture carrier  344  skims or slides along the surface of the bone  380 , maximizing the depth of penetration, but not digging in or penetrating the bone surface. 
   Referring now to  FIG. 17C , the coupling  338  reaches a point in its travel along the track  340  where it pushes the downstop washer  358  against the wall  356  of the pocket  354 . This action limits the outward travel of the suture carrier  344  to prevent overdriving and reduces or eliminates the possibility of expelling the suture carrier  344  from the distal tip  306 . The suture carrier  344  drives the formed tip  376  and attached suture  374  through ligament  378  and into the catch  360 , where it is received and retained in a manner previously described. As the button  308  is released, the spring  324  urges the button  308  proximally, moving the pusher wire  330 , the coupling  338 , the carrier wire  342 , and the suture carrier  344  along with it to the position shown in  FIG. 17D , where the backstop washer  348  arrests the proximal movement in a manner previously described, leaving the formed tip  376  in the catch  360  and the suture  374  driven through the ligament  378 . 
   A variation of this embodiment can be seen with respect to  FIGS. 10 and 16 . In the embodiment shown in  FIG. 10 , the path of the suture carrier  868 , illustrated by a phantom line in  FIG. 10 , exits the housing  860  in a direction that is substantially perpendicular to the surface of the housing  860  and presents an opportunity for the suture carrier  868  to be driven directly into the tissue surface placed against the exit port. Thus, if there were bone immediately underlying that tissue, this would allow the sharpened end of the suture carrier  868  to be driven directly into bone. In the embodiment shown in  FIG. 16 , a phantom line illustrates a different type of carrier path. In this embodiment, the carrier path exits the distal tip  306  in a direction that approaches being substantially tangential to the surface of the distal tip  306 . This substantially tangential exit path allows this instrument to achieve the skimming tissue bite referred to earlier. As shown in  FIGS. 17A-17D , when the surface surrounding the exit port of this device is placed next to a tissue surface, the sharpened end of the suture carrier  344  takes a skimming tissue bite, thereby minimizing any possible penetration of bone underlying the tissue. 
   Another aspect of this embodiment which is advantageous to the function of the device is the ability to rotate the distal tip  306  of the instrument relative to the elongate body  304 , thereby allowing the instrument to conform to the contours of, for example, the pelvic brim. This is accomplished by incorporating the construction illustrated in  FIGS. 18A and 18B . For clarity, the elongate body  304  has been shown in partial cross-section so that the depression  370  may be seen to engage the rotation pockets  372   a,b . This engagement couples the distal tips  306   a,b  to the elongate body  304 , as previously described, and also allows the assembly of the distal tips  306   a,b  to be rotated axially along the cylindrical surface  320 . 
   In yet another embodiment, the instrument can be adapted to facilitate access into the abdominal cavity and the placement of suture(s) radially in a body lumen. Such instrument may be particularly useful where anastomosis is required such as urethral anastomosis following radical prostatectomy or in blood vessel or bowel anastomosis. Referring to  FIGS. 19A-19C , the suturing instrument  66  includes an elongated body member  82  and a rotatable head  124 . The elongated body member  82  can include an elbow  122  (or bend). The head  124  rotates by angular increments. The elongated body member  82  includes an engaging element located at its distal end  128 . The head  124  includes an engaging element located at its proximal end  126  for mating with the engaging element of the elongated body member  82 . The head  124  includes a dilator cap or a bullet-shaped end at the distal end  130  of the head  124  to maintain the urethra or any other body lumen in a dilated configuration. The rotation of the head  124  is performed manually between each application of a suture in a body lumen and before reloading with the needle and suture to permit application of a series of sutures along the circumference of the lumen, at incremental angular positions that can be as small as 10°. The embodiment of the suturing instrument featuring an elbow and rotatable head is particularly adapted to perform suturing after removal of the prostate to connect the bladder to the urethra or generally following any other type of resection. 
   In one embodiment, the rotatability of the head  124  is accomplished with the structure depicted in  FIGS. 19D-19F . The head  124  includes an engaging element with a male configuration  123 . The male configuration  123  includes a series of fluted cuts  133  located along 330° of its perimeter. The male configuration  123  includes a stop to prevent the head  124  from rotating 360°. The elongated body member  82  includes an engaging element with a female configuration  125  and a flexible detent  131 . The female configuration  125  is a substantially circular recess with the flexible detent  131  mounted within the elongated body member  82  and protruding into the substantially circular recess. The flexible detent  131  can be a length of spring wire or a pin and can be made of nitinol. The head  124  can be positioned by rotating the male configuration  123  engaging element with respect to the female configuration  125  engaging element, deflecting the flexible detent  131 , and then allowing the flexible detent  131  to mechanically engage the fluted cut  133  which corresponds to the desired angular orientation. The head can be positioned in angular increments of 30°. In addition, the head  124  depicted in  FIGS. 19D-19F  includes a suture carrier  127  and a catch mechanism  129 , which perform substantially the same and are constructed substantially the same as the prior-described suture carriers and catches. 
   Having described certain embodiments of the invention, it will be apparent to those of ordinary skill in the art that other embodiments incorporating the concepts disclosed herein can be used without departing from the spirit and the scope of the invention. Accordingly, the described embodiments are to be considered in all respects only as illustrative and not restrictive.