Patent Abstract:
A device is disclosed for introducing a flexible elongated element through at least two portions of a subject. In an embodiment, the device includes a proximal end and a distal end, as well as an advancement unit for longitudinally advancing the flexible elongated element toward the distal end such that a distal end of the elongated element may pass from the distal end of said device with sufficient force to pass through the portions of the subject. The device also includes a securing unit for variably adjusting a securing force applied by the flexible elongated element to secure together the portions of the subject.

Full Description:
REFERENCE TO EARLIER APPLICATIONS 
     This is a continuation-in-part of pending prior U.S. patent application Ser. No. 10/014,991, filed Dec. 11, 2001 by Gregory E. Sancoff et al. for SURGICAL SUTURING INSTRUMENT AND METHOD OF USE. 
     This patent application also claims benefit of now abandoned prior U.S. Provisional Patent Application Ser. No. 60/322,409, filed Sep. 14, 2001 by Frederic P. Field et al. for ENDOSCOPIC SUTURING INSTRUMENT. 
     The two above-identified documents are hereby incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     This invention relates to medical instruments and procedures in general, and more particularly to suturing instruments and methods for suturing. 
     BACKGROUND OF THE INVENTION 
     Suturing instruments are typically used to draw together two or more portions of a subject patient (e.g., tissue such as muscle or skin) or to attach an object to the patient (e.g., to attach a piece of surgical mesh to the abdominal wall of the patient during hernia repair surgery). 
     Certain suturing instruments employ a needle that precedes a length of suture material through a subject. 
     For example, U.S. Pat. Nos. 3,470,875; 4,027,608; 4,747,358; 5,308,353; 5,674,230; 5,690,653; 5,759,188; and 5,766,186 generally disclose suturing instruments in which a needle, with trailing suture material, is passed through a subject. 
     U.S. Pat. Nos. 4,890,615; 4,935,027; 5,417,700; and 5,728,112 generally disclose suturing instruments in which suture material is passed through the end of a hollow needle after that needle has passed through a subject. 
     With all of the foregoing devices, a needle must be passed through the subject in order to deploy the suture. This is generally undesirable, since the needle typically leaves a larger hole in the subject than is necessary to accommodate only the suture material. In this respect it should be appreciated that it is generally desirable to alter each portion of the material being sutured as little as possible. 
     A suturing instrument has been devised which permits the suture material itself to pierce the subject without the use of a needle. However, this device does not permit sufficient flexibility with regard to the amount of tension that may be applied to the suture and tissue. 
     More particularly, U.S. Pat. No. 5,499,990 discloses a suturing instrument in which a 0.25 mm stainless steel suturing wire is advanced to the distal end of a suturing instrument, whereupon the distal end of the suturing wire is caused to travel in a spiral direction so as to effect stitches joining together two portions of a subject. After the spiral is formed, the beginning and end portions of the suture may be bent toward the tissue in order to inhibit retraction of the suture wire into the tissue upon removal of the suturing instrument. The stainless steel wire is sufficiently firm to hold this locking set. In addition, after the spiral is formed, the radius of the deployed suture spiral may then be decreased by advancing an outer tube over a portion of the distal end of the instrument. Again, the stainless steel wire is sufficiently firm to hold this reducing set. 
     Unfortunately, however, such a system does not permit sufficient flexibility in all situations with regard to the appropriate amount of tension to be applied to the subject, since the wire is relatively firm (i.e., firm enough to hold its sets). Such a system also does not provide sufficient flexibility with regard to the appropriate type of suture stitch to be applied, since the device is specifically configured to provide only a spiral suture stitch. 
     In contrast to the aforementioned limitations of the suturing instrument of U.S. Pat. No. 5,499,990, it is desirable that a suturing instrument approximate the portions of the material which is to be joined in the correct physiological relationship, and to urge the portions together with an appropriate amount of force. If too much force (or tension) is applied to the suture material, then the subject portions may become necrotic or the sutures may cut through the subject. If too little tension is applied to the suture material, then the healing process may be impaired. 
     U.S. Pat. No. 4,453,661 discloses a surgical instrument for applying staples. The staples are formed from the distal end of a length of wire. The distal end of the wire is passed through a subject, and thereafter contacts a die that causes the wire to bend, thereby forming the staple. The wire is sufficiently firm to take the set imposed by the die. The staple portion is then cut from the wire by a knife. Again, such a system suffers from the fact that it does not permit sufficient flexibility in all situations with regard to the appropriate tension to be applied to the subject, since the attachment is made by a staple which has a predefined geometry and is formed with relatively firm wire. In addition, the system is limited as to the type of fastening which may be applied, since the surgical instrument is limited to only applying wire staples. 
     There is a need, therefore, for a new suturing device that permits minimally disruptive suturing and permits flexibility in the placement, application, and tensioning of the suture material. 
     SUMMARY OF THE INVENTION 
     The invention provides a device for introducing a flexible elongated element through a subject. In one embodiment, the device includes a proximal end and a distal end, as well as an advancement unit for longitudinally advancing the flexible elongated element toward the distal end of the device such that a distal end of the flexible elongated element may pass from the distal end of the device with sufficient force to pass through the subject. The device also includes a securing unit for variably adjusting a securing force applied by the flexible elongated element so as to provide the desired securement to the subject. 
     In further embodiments, the device includes a guide tube for guiding the flexible elongated element through the device, toward the distal end of the device, as well as a rotation unit for rotating the distal end of the device so as to cause the flexible elongated element to wrap around itself, whereby to adjustably apply the securing force to the flexible elongated element. 
     In another aspect of the invention, there is provided a suturing device comprising: a housing; a shaft extending distally from said housing, at least a portion of said shaft being flexible; a pair of opposing jaws located at a distal end of said shaft; a suture drive mechanism located in said housing and adapted to advance suture material through said shaft, through one of said jaws, through a subject to be sutured, and into the other jaw; and a jaw rotation mechanism located in said housing and adapted to rotate said jaws so as to secure the suture material to the subject. 
     In another aspect of the invention, there is provided a suturing device comprising: a housing; a shaft extending distally from said housing; a pair of opposing jaws located at a distal end of said shaft, said opposing jaws being (i) pivotally connected to said distal end of said shaft, and (ii) pivotally connected to an inner yoke movable relative to said distal end of said shaft, whereby movement of said inner yoke in a distal direction causes said opposing jaws to open relative to one another, and movement of said inner yoke in a proximal direction causes said opposing jaws to close relative to one another; a suture drive mechanism located in said housing and adapted to advance suture material through said shaft, through one of said jaws, through a subject to be sutured, and into the other jaw; and a jaw rotation mechanism located in said housing and adapted to rotate said jaws so as to secure the suture material to the subject. 
     In another aspect of the invention, there is provided a suturing device comprising: a housing; a shaft extending distally from said housing, at least a portion of said shaft being flexible; a pair of movable jaws pivotally connected to the distal end of said shaft in opposing relation such that said jaws can open and close relative to one another; a suture drive mechanism located in said housing and adapted to advance suture material through said shaft, through one of said jaws, through a subject to be sutured, and into the other jaw; a jaw rotation mechanism located in said housing and adapted to rotate said jaws so as to secure the suture material to the subject. 
     In another aspect of the invention, there is provided a suturing device comprising: a housing; a shaft extending distally from said housing; a pair of opposing jaws located at a distal end of said shaft; a suture drive mechanism located in said housing and adapted to advance suture material through said shaft, through one of said jaws, through a subject to be sutured, and into the other jaw; a jaw rotation mechanism located in said housing and adapted to rotate said saws so as to secure the suture material to the subject; and a source of suture material located in the device, said suture material comprising (i) a distal portion having properties favorable for penetrating, twisting and cutting operations, and (ii) a proximal portion having properties favorable for driving operations, said source of suture material being located in the device so that said proximal portion is engaged by said suture drive mechanism. 
     In another aspect of the invention, there is provided a suture material, comprising: a distal portion having properties favorable for penetrating, twisting and cutting operations; and a proximal portion having properties favorable for driving operations. 
     In another aspect of the invention, there is provided a method for treating gastroesophogeal reflux disease (GERD), comprising: providing a suturing device comprising: a housing; a shaft extending distally from said housing; a pair of opposing jaws located at a distal end of said shaft; a suture drive mechanism located in said housing and adapted to advance suture material through said shaft, through one of said jaws, through a subject to be sutured, and into the other jaw; and a jaw rotation mechanism located in said housing and adapted to rotate said jaws so as to secure the suture material to the subject; advancing the distal end of the suturing device into a patient&#39;s stomach so that the distal end of the suturing device is adjacent to the wall of the stomach below the lower esophageal sphincter (LES); gathering together portions of the stomach wall below the LES with the pair of opposing jaws; operating the suture drive mechanism so as to advance suture material through the gathered-together portions of the stomach wall; and operating the jaw rotation mechanism so as to secure the suture material to the subject and thereby secure together the gathered-together portions of the stomach wall. 
     In another aspect of the invention, there is provided a method for effecting hemostasis, comprising: providing a suturing device comprising: a housing; a shaft extending distally from said housing; a pair of opposing jaws located at a distal end of said shaft; a suture drive mechanism located in said housing and adapted to advance suture material through said shaft, through one of said jaws, through a subject to be sutured, and into the other jaw; and a jaw rotation mechanism located in said housing and adapted to rotate said jaws so as to secure the suture material to the subject; advancing the distal end of the suturing device into a patient adjacent to tissue which would benefit by effecting hemostasis; gathering together portions of the tissue which would benefit by effecting hemostasis with the pair of opposing jaws; operating the suture drive mechanism so as to advance suture material through the gathered-together portions of the tissue; and operating the jaw rotation mechanism so as to secure the tissue and thereby effect hemostasis. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and other objects and features of the present invention will be more fully disclosed or rendered obvious by the following detailed description of the preferred embodiment of the invention, which is to be considered together with the accompanying drawings wherein like numbers refer to like parts, and further wherein: 
         FIG. 1  is a side view of a suturing instrument formed in accordance with the present invention; 
         FIG. 2  is a partial side view, partially in section, of the suturing instrument shown in  FIG. 1 ; 
         FIG. 3  is a partial top view, partially in section, of the suturing instrument shown in  FIG. 1 ; 
         FIG. 4  is a schematic partial side view showing some of the internal components of the suturing instrument shown in  FIG. 1 ; 
         FIG. 4A  is a perspective view of a drive barrel assembly incorporated in the suturing instrument shown in  FIG. 1 ; 
         FIG. 5  is a perspective view of a wire guide support unit incorporated in the suturing instrument shown in  FIG. 1 ; 
         FIG. 6  is a perspective view of the suturing instrument&#39;s wire supply cartridge, which includes the wire guide support unit shown in  FIG. 5 ; 
         FIG. 7  is a perspective view, partially in section, of the wire supply cartridge shown in  FIG. 6 ; 
         FIG. 8  is a perspective rear view of the drive barrel assembly incorporated in the suturing instrument shown in  FIG. 1 , with the drive barrel assembly&#39;s release lever being shown in its closed position; 
         FIG. 9  is a perspective view of the proximal (i.e., rear) end of the drive barrel assembly shown in  FIG. 8 , with the release lever being shown in its open position; 
         FIG. 10  is a perspective view of the proximal (i.e., rear) end of the same drive barrel assembly, with the release lever being shown in its closed position, and with the wire guide and wire guide support unit being advanced relative to the drive barrel assembly (but with the remainder of the wire supply cartridge being removed from view); 
         FIG. 11  is a schematic view taken along the line  11 — 11  of  FIG. 4 ; 
         FIG. 12  is a side view of a shaft and an end effector portion of the suturing instrument shown in  FIG. 1 ; 
         FIG. 13  is a side view of the end effector portion of the suturing instrument shown in  FIG. 1 ; 
         FIG. 14  is a side view, partially in section, of the end effector portion shown in  FIG. 13 , with the end effector portion being shown with its cutting bar in its forward (i.e., non-cutting) position; 
         FIG. 15  is a side view, partially in section, of the end effector portion shown in  FIG. 14 , but with the end effector portion being shown with its cutting bar in its retracted (i.e., cutting) position; 
         FIG. 16  is a perspective view of the end effector portion of the suturing instrument shown in  FIG. 1 ; 
         FIGS. 17A–17J  show various steps in a suturing operation conducted with the suturing instrument shown in  FIG. 1 ; 
         FIG. 18  is a sectional view showing one possible construction for the suturing instrument&#39;s fixed jaw portion and its associated cutting bar; 
         FIG. 19  is a side view showing a piece of wire cut with the apparatus shown in  FIG. 18 ; 
         FIG. 20  is a sectional view showing another possible fixed construction for the suturing instrument&#39;s fixed jaw portion and its associated cutting bar; 
         FIG. 21  is a side view showing a piece of wire cut with the apparatus shown in  FIG. 20 ; 
         FIG. 22  is a side view, partially in section, of the end effector portion of the device, wherein the end effector portion includes a piezoelectric element to aid in wire penetration; 
         FIG. 23A  is a schematic diagram of the device&#39;s fixed jaw portion, illustrating how the suture wire may sometimes curve as it exits the fixed jaw portion; 
         FIG. 23B  is a schematic diagram of a modified form of the device&#39;s fixed jaw portion, illustrating how the profile of the device can be modified so as to counteract the aforementioned wire curvature; 
         FIG. 23C  is a schematic diagram of a modified form of the device&#39;s movable jaw portion, illustrating how the mouth of the movable jaw portion&#39;s opening may be enlarged so as to facilitate suture capture; 
         FIG. 24  is a schematic diagram of a modified form of the device, wherein one or more legs have been provided to help stabilize the tissue during suturing; 
         FIG. 25  is a schematic diagram of another modified form of the device, wherein a second set of jaws have been added to the device to help stabilize the tissue during suturing; 
         FIGS. 26–29   a  are schematic diagrams of a preferred embodiment of the present invention illustrating a novel procedure to address gastroesophogeal reflux disease (GERD); 
         FIGS. 30–39  are schematic diagrams of modified forms of suturing instruments with two movable jaw portions for gripping tissue; and 
         FIG. 40  is a schematic diagram of a supply suture wire having a softer distal wire portion optimized for tissue penetration, twisting and cutting, and a harder proximal wire portion optimized for driving. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Overview 
     Looking first at  FIG. 1 , there is shown a suturing instrument  10  which comprises a preferred embodiment of the present invention. Suturing instrument  10  includes a housing  12 , a handle  14 , a shaft  16  and an end effector  18 . Suturing instrument  10  also includes a wire advance button  20 , a jaw closing actuator  22 , a wire cutting actuator  24 , a left-thumb-actuated rotation button  26 , and a right-thumb-actuated rotation button  28  ( FIG. 3 ). Suturing instrument  10  also includes a wire supply cartridge  30 , as well as a shaft retaining nut  32 . Shaft retaining nut  32  allows shaft  16  to be dismounted from the remainder of the device for cleaning purposes. 
     As will be discussed in further detail below, generally during use, suture wire (comprising wire formed of metal or any other suitable material having the required flexibility and stiffness) is drawn from a winding in wire supply cartridge  30  and is pushed through housing  12  and shaft  16  to end effector  18 , which includes a pair of opposing jaw portions. The jaw portions may be brought together around the material which is to be sutured by actuating jaw closing actuator  22  when the jaw portions are positioned at an appropriate surgical location. The suture wire is driven through housing  12  and shaft  16  to end effector  18  by actuating wire advance button  20 . The suture wire is driven from one jaw portion to the other jaw portion with sufficient force to penetrate the tissue placed between the jaw portions, and the suture wire is permitted to pass through the second jaw portion. The jaw portions are then permitted to separate and move away from the tissue, leaving the suture wire extending from the subject tissue to each of the two jaw portions. Shaft  16  and end effector  18  (together with wire supply cartridge  30 ) may then be rotated with respect to housing  12  and handle  14  by actuating either left-thumb-actuated rotation button  26  or right-thumb-actuated rotation button  28 . This causes the portions of the suture wire that extend from the tissue to be twisted about one another so as to form a closed loop extending through the tissue. It will be appreciated that the size of this closed loop may be adjustably reduced by increasing the degree of twisting in the wire. The twisted loop of suture wire may then be cut off, at end effector  18 , from the remaining portion of the suture wire that extends back through the suturing instrument. Such cutting may be effected by actuating wire cutting actuator  24 . 
     As will be discussed in further detail below, wire supply cartridge  30  may be supplied separately from suturing instrument  10 , with the wire supply cartridge  30  being loaded into suturing instrument  10  prior to commencing a suturing operation. As will also be discussed in further detail below, wire supply cartridge  30  may be disposable, such that the cartridge may be discarded after all of its wire has been used up. 
     Construction Details 
     As shown in  FIGS. 2 and 4 , handle  14  provides a cavity that may receive batteries  34 . In other embodiments, the unit may be powered remotely via a power transmission cord or any other source of suitable power. 
     Batteries  34  supply a ground (or negative) potential to a ground connector post  36  ( FIG. 2 ), which in turn communicates with a rotary ground communicator  38 . Rotary ground communicator  38  permits electrical contact to be maintained with ground connector post  36  when rotary ground communicator  38  is rotated with respect to ground connector post  36 , as occurs when shaft  16  and end effector  18  are rotated so as to twist closed suture wire extending through the tissue. 
     Batteries  34  supply a positive potential to wire advance button  20 , and to a first connector post  40 , which in turn communicates with a first rotary electrical communicator  42 . First rotary electrical communicator  42  permits electrical contact to be maintained with first connector post  40  when first rotary electrical communicator  42  is rotated with respect to first connector post  40 . The positive potential from batteries  34  is also supplied (in parallel) to each thumb-activated rotation button  26 ,  28  ( FIG. 3 ), and to a second connector post  44  ( FIG. 2 ), which in turn communicates with a second rotary electrical communicator  46 . Again, second rotary electrical communicator  46  permits electrical contact to be maintained with second connector post  44  when second rotary electrical communicator  46  is rotated with respect to second connector post  44 . Each of the connector posts  36 ,  40  and  44  may be spring-biased so as to remain in contact with its respective rotary communicator. In view of the foregoing construction, the positive potentials may be switched on by depressing the respective actuator button  20 ,  26 ,  28 . Handle  14  also includes a cap  48  which may be removed so as to permit insertion of batteries  34 . 
     First rotary electrical communicator  42  is in electrical communication with a wire advance motor  50  shown in  FIGS. 2 and 4 . The output shaft of wire advance motor  50  is coupled to a miter drive gear  52 , which is in turn coupled to a miter follower gear  54 . Miter follower gear  54  is coupled to a drive wheel  56  which contacts the suture wire  58 , as will be described in further detail below with reference to  FIGS. 5-10 . 
     Second rotary electrical communicator  46  is in electrical communication with a shaft rotation motor  60  ( FIGS. 3 and 4 ), the output of which is coupled to a pinion gear  62  ( FIGS. 4 ,  4 A and  11 ) that rotates along an internal gear  64  ( FIGS. 4 and 11 ). As shown in  FIG. 3 , left-thumb-actuated rotation button  26  and right-thumb-activated rotation button  28  may be provided to permit the user to use the thumb of either their left hand or their right hand, respectively, so as to actuate shaft rotation motor  60 . In this respect it will be appreciated that, inasmuch as left-thumb-actuated rotation button  26  and right-thumb-actuated rotation button  28  are wired in parallel, shaft rotation motor  60  will rotate in the same direction regardless of which button (i.e., button  26  or button  28 ) may be actuated. 
     Jaw closing actuator  22  ( FIGS. 2 and 4 ) is coupled to a jaw linkage coupler  66 , which in turn contacts a jaw linkage  68  ( FIGS. 2 and 14 ). When jaw closing actuator  22  is pulled toward handle  14  ( FIG. 2 ), jaw closing actuator  22  pivots on its pivot pin  67  ( FIG. 4 ) so as to drive jaw linkage coupler  66  distally, against the force of biasing spring  69 , and so as to cause the jaw linkage  68  to move forward toward the distal end of suturing instrument  10 . This action will in turn cause movable jaw portion  98  to close on fixed jaw portion  96  ( FIG. 17A ), as will hereinafter be discussed in further detail. When jaw closing actuator  22  is subsequently released, biasing spring  69  ( FIG. 4 ) drives jaw linkage coupler  66  proximally, so as to cause jaw linkage  68  to move proximally. This action will cause movable jaw portion  98  to open relative to fixed jaw portion  96  ( FIG. 14 ), as will hereinafter be discussed in further detail. The action of jaw linkage  68  at the distal end of the device is discussed further below with reference to  FIGS. 13 and 14 . 
     Wire cutting actuator  24  is coupled to a wire cutting linkage coupler  70  ( FIGS. 2 and 4 ), which in turn contacts a wire cutting linkage  72  ( FIGS. 2 ,  14  and  15 ). When wire cutting actuator  24  is pulled toward handle  14  ( FIG. 2 ), wire cutting actuator  24  pivots on its pivot pin  73  ( FIG. 4 ) so as to drive wire cutting linkage coupler  70  proximally, against the force of biasing spring  69 , and so as to cause wire cutting linkage  72  to move proximally, away from the distal end of suturing instrument  10 . This action will in turn cause cutting bar  104  ( FIG. 14 ) to move proximally ( FIG. 15 ) so as to effect wire cutting, as will hereinafter be discussed in further detail. When wire cutting actuator  24  is subsequently released, biasing spring  69  drives wire cutting linkage coupler  70  distally, so as to cause wire cutting linkage  72  to move distally. This action causes cutting bar  104  to move distally, so as to assume the position shown in  FIG. 14 . Wire cutting linkage  72  moves adjacent to, and independent of, jaw linkage  68  discussed above. The action of wire cutting linkage  72  at the distal end of the device is discussed further below with reference to  FIGS. 14 and 15 . 
     The wire supply cartridge  30  shown in  FIG. 1  includes a wire guide support unit  74 , as shown in  FIGS. 5–7 . A supply coil of suture wire  58  (comprising wire formed of metal or any other suitable material having the required flexibility and stiffness) may be supplied in the base of cartridge  30  and is fed into the support unit  74  as shown in  FIG. 7 . A wire guide  76  surrounds suture wire  58 , from support unit  74  to the distal end of suturing instrument  10 , adjacent to end effector  18  ( FIGS. 5–7 ,  14  and  15 ). Wire guide  76  ensures that suture wire  58  does not bend or buckle as the suture wire is pushed through housing  12  and shaft  16 . More particularly, wire guide  76  preferably forms a sufficiently close sliding fit with suture wire  58  such that suture wire  58  cannot bend or buckle as the suture wire is advanced through suturing instrument  10 . At the same time, wire guide  76  is also formed so as to present a minimum of friction to suture wire  58  as the suture were is advanced through the instrument. The foregoing characteristics are important, inasmuch as suture wire  58  is extremely thin and flexible and highly susceptible to bending or buckling in the absence of some sort of lateral support. 
     By way of example but not limitation, where suture wire  58  is formed out of stainless steel and has a diameter of 0.005 inch, wire guide  76  might have an inside diameter of 0.008 inch and an outside diameter of 0.016 inch. In addition, wire guide  76  is preferably formed out of polytetrafluoroethylene (PTFE) or some other relatively lubricious material. Alternatively, the interior of wire guide  76  may be coated with a lubricant so as to facilitate closely-supported, low-friction passage of the suture wire through the wire guide. 
     Further by way of example but not limitation, in one preferred form of the invention, suture wire  58  may comprise 316 LVM stainless steel having a tensile strength of 170 kpsi. 
     Although wire guide  76  extends through support unit  74  ( FIG. 7 ), wire guide  76  has two openings  78  (one on either side of wire guide  76 , only one of which is shown in  FIG. 5 ) in the center of support unit  74 . Openings  78  expose a portion of suture wire  58  so that wire drive wheel  56  ( FIG. 8 ) may contact suture wire  58  and urge the suture wire forward toward the distal end of suturing instrument  10 , as will be discussed in detail below with reference to  FIGS. 8–10 . 
     As shown in  FIGS. 2 ,  3 ,  4 A and  8 , housing  12  receives a drive barrel assembly  80  that contains the aforementioned motors  50  and  60 , and provides a distally-extending barrel shaft  81  ( FIGS. 4A and 8 ), on the outside of which are located the rotary communicators  38 ,  42  and  46 . A recess  82  ( FIG. 4A ) is provided on the distal end of barrel shaft  81  for receiving a coupling pin  84  ( FIGS. 2 and 4 ) which is located on the proximal end of shaft  16 , such that rotation of drive barrel assembly  80  causes rotation of coupling pin  84  and hence shaft  16 . Drive barrel assembly  80  is rotationally held within housing  12  by bearings  86 , as shown in  FIGS. 2 and 3 . 
     Looking next at  FIGS. 7–10 , wire supply cartridge  30  may be attached to drive barrel assembly  80  by rotating a release lever  87  away from the center of drive barrel assembly  80  ( FIGS. 8 and 9 ), so as to move a carriage  88  relative to drive barrel assembly  80 . Most particularly, release lever  87  rides on a pin  90 , and rotation of release lever  87  from the position shown in  FIG. 8  to the position shown in  FIG. 9  draws carriage  88 , as well as a wire follower wheel  92 , away from the center of drive barrel assembly  80 . Once wire follower wheel  92  is separated from wire drive wheel  56  by a sufficient distance to expose the drive barrel assembly&#39;s central passageway  93  ( FIG. 9 ), wire guide  76  (overlying suture wire  58 ) may be inserted into passageway  93  ( FIG. 10 ), and wire guide support unit  74  ( FIGS. 6 ,  7  and  10 ) may be inserted between wheels  56  and  92  ( FIG. 10 ), such that wheels  56  and  92  contact either side of suture wire  58  through openings  78  formed in either side of wire guide  76 . A biasing spring  94  ( FIGS. 8–10 ) is provided on carriage  88  to urge wire follower wheel  92  into close contact with suture wire  58 . In other embodiments, wire follower wheel  92  may also be driven indirectly by wire drive wheel  56  in order to provide additional forces to move suture wire  58  distally (i.e., forward, toward the tool&#39;s end effector  18 ). 
     Pinion gear  62  ( FIGS. 4 ,  4 A and  11 ) extends distally from drive barrel assembly  80  and engages the housing&#39;s internal gear  64 , as shown in  FIGS. 4 and 11 . As a result of this construction, when shaft rotation motor  60  is actuated, pinion gear  62  rotates around internal gear  64 , bringing with it the entire drive barrel assembly  80 . This in turn causes shaft  16  to rotate, since shaft  16  is coupled to drive barrel assembly  80 . More particularly, the rotation of drive barrel assembly  80  is transferred to shaft  16  through the shaft&#39;s coupling pin  84  ( FIGS. 2 ,  4  and  12 ), which is seated in recess  82  ( FIG. 8 ) of drive barrel assembly  80 . 
     End effector  18  (FIGS.  1  and  13 – 16 ) includes the fixed jaw portion  96  and the movable jaw portion  98 . Movable jaw portion  98  is coupled to the aforementioned jaw linkage  68  ( FIG. 14 ) via a jaw linkage pin  100 , such that when jaw linkage  68  is moved distally (i.e., by pulling jaw closing actuator  22  toward handle  14 ), jaw portion  98  is rotated about a pivot pin  102  ( FIG. 13 ) and closes onto fixed jaw portion  96 . Conversely, when jaw linkage  68  is moved proximally (i.e., by the power of biasing spring  69  acting on jaw linkage coupler  66  and hence jaw linkage  68 ), movable jaw portion  98  will open away from fixed jaw portion  96 . It will be appreciated that the force of biasing spring  69  will normally keep movable jaw portion  98  open relative fixed jaw portion  98  ( FIGS. 1 ,  13  and  14 ), unless and until jaw closing actuator  22  is activated so as to overcome the bias of spring  69 . 
     Wire cutting linkage  72  ( FIGS. 2 ,  3 ,  14  and  15 ) is coupled to the cutting bar  104  ( FIGS. 14 and 15 ) that includes a small opening  106  through which suture wire  58  may pass, as will hereinafter be discussed in further detail. Preferably cutting bar  104  is slidably received in a passageway  107  ( FIGS. 14 ,  15 ,  16  and  17 H) formed in fixed jaw portion  96 . In one position ( FIG. 14 ), cutting bar  104  is positioned in fixed jaw portion  96  such that the cutting bar&#39;s opening  106  is aligned with a channel  108  formed in fixed jaw portion  96 , whereby suture wire may be passed from the distal end of wire guide  76 , through channel  108  formed in fixed jaw portion  96  (where it undergoes an approximately 90 degree change of direction), through opening  106  in cutting bar  104 , through a channel extension  108 A formed in fixed jaw portion  96 , and across to movable jaw portion  98 , as will hereinafter be discussed in further detail. However, when wire cutting linkage  72  is moved proximally by pulling wire cutting actuator  24  toward handle  14 , cutting bar  104  is also moved proximally ( FIG. 15 ) so as to cut any suture wire extending from channel  108  (in fixed portion  96 ) into opening  106  (in cutting bar  104 ). In this respect it will be appreciated that it is desirable to form channel extension  108 A with a length greater than channel  108  (see  FIGS. 14 and 15 ) so as to prevent the suture wire from being cut in two places (i.e., at channel  108  and again at channel extension  108 A) when cutting bar  104  is moved proximally by pulling on wire cutting actuator  24 . At the same time, however, it should also be appreciated that the fixed jaw portion&#39;s channel  108  and channel extension  108 A, and the cutting bar&#39;s opening  106 , are all sized, relative to suture wire  58 , so as to provide as much support as possible to the suture wire as it passes through, and out of, fixed jaw portion  96 . 
     It will be appreciated that the force of biasing spring  69  will normally keep cutting bar  104  in its distal position (i.e., with the cutting bar&#39;s opening  106  aligned with the fixed jaw portion&#39;s channel  108 ), unless and until wire cutting actuator  24  is activated so as to overcome the bias of spring  69 . 
     In view of the foregoing construction, it will be seen that: (1) release lever  87  ( FIGS. 8–10 ) may be activated so as to move wire follower wheel  92  away from, and toward, wire drive wheel  56  so as to permit a full wire supply cartridge  30  (FIGS.  1  and  5 – 7 ) to be loaded into suturing instrument  10 ; (2) activating jaw closing actuator  22  will cause movable jaw portion  98  to close on fixed jaw portion  96 ; (3) activating wire advance button  20  will cause wire drive wheel  56  to advance suture wire  58  through housing  12  and shaft  16 ; (4) activating rotation button  26  and/or rotation button  28  will cause shaft  16  to rotate relative to housing  12 ; and (5) activating wire cutting actuator  24  will cause cutting bar  104  to move proximally so as to sever any suture wire extending from fixed jaw portion  96 . 
     Operation 
     Suturing instrument  10  may be used to apply wire suture  58  to a subject so as to effect a desired suturing operation. 
     By way of example but not limitation, and looking now at  FIGS. 17A–17J , suturing instrument  10  may be used to suture together two portions  110 ,  112  of a subject which is to be sutured. In a typical case, portions  110 ,  112  might comprise two sections of severed tissue which need to be reattached to one another, or two pieces of previously unattached tissue which need to be attached to one another. However, one or the other of the portions  110 ,  112  might also comprise artificial mesh or some other object being attached to tissue, etc. In addition, in a typical case, portions  110 ,  112  might be located relatively deep within a patient, and might be accessed during a so-called “minimally invasive”, or a so-called “closed surgery”, procedure; however, in other circumstances, portions  110 ,  112  might be accessed during a conventional, or so-called “open surgery”, procedure. This later situation might include procedures done at the outer surface of the patient&#39;s body, i.e., where portions  110 ,  112  comprise surface subjects. 
     In any case, suturing instrument  10  is initially prepared for use by installing batteries  34  into handle  14 , if batteries  34  are not already installed, and by installing wire supply cartridge  30  into the suturing instrument, if a cartridge  30  is not yet installed. As noted above, wire supply cartridge  30  is installed in suturing instrument  10  by (1) moving the drive barrel assembly&#39;s release lever  87  to its open position ( FIG. 9 ), so as to move wire follower wheel  92  away from wire drive wheel  56  and thereby expose the barrel assembly&#39;s central passageway  93 ; (2) passing the distal end of the cartridge (i.e., the distal end of wire guide  76 ) through drive barrel assembly  80  and shaft  16  until the distal end of wire guide  76  is in communication with the channel  108  formed in fixed jaw portion  96  ( FIG. 14 ), at which point the cartridge&#39;s wire guide support unit  74  will be positioned intermediate wire drive wheel  56  and wire follower wheel  92  ( FIG. 2 ); and (3) moving the drive barrel assembly&#39;s release lever  87  back to its closed position ( FIG. 8 ), so as to cause wire drive wheel  56  and wire follower wheel  92  to extend through the wire guide&#39;s openings  78  and engage suture wire  58 . 
     At this point suturing instrument  10  will be ready for use, with its movable jaw portion  98  being opened away from its fixed jaw portion  96 , and with its cutting bar  104  being in its forward ( FIG. 14 ) position. 
     Next, suturing instrument  10  has its movable jaw portion  98  moved into engagement with its fixed jaw portion  96  (i.e., the jaws  96 ,  98  are placed in their “closed” position) by pulling jaw closing actuator  22  toward handle  14 , and then the distal end of suturing instrument  10  is moved adjacent to subject portions  110 ,  112  ( FIG. 17A ). 
     In the case of a so-called closed surgical procedure, such positioning will generally involve moving the distal end of the suturing instrument through a cannula and into an interior body cavity; however, it is also envisioned that one might move the distal end of the suturing instrument directly into an otherwise-accessible body cavity, e.g., directly into the colon or esophagus, etc. In the case of a so-called open surgical procedure, such positioning might involve positioning the distal end of the suturing instrument adjacent to more readily accessible subject portions  110 ,  112 . 
     In any case, once the distal end of suturing instrument  10  has been placed adjacent to subject portions  110 ,  112 , jaw closing actuator  22  is released, such that biasing spring  69  ( FIG. 4 ) will cause movable jaw portion  98  to open away from fixed jaw portion  96  ( FIG. 171B ). Then the distal end of suturing instrument  10  is moved so that its jaws  96 ,  98  straddle subject portions  110 ,  112 , and then jaw closing actuator  22  is actuated again, by pulling jaw closing actuator  22  toward handle  14 , so as to close movable jaw portion  98  against fixed jaw portion  96 , whereby to capture subject portions  110 ,  112  ( FIG. 17C ). 
     Next, wire advance button  20  is activated so as to cause suture wire  58  to be driven forward, out of the distal end of wire guide  76 , through the fixed jaw portion&#39;s channel  108 , through opening  106  in cutting bar  104 , through the fixed jaw portion&#39;s channel extension  108 A, through subject portions  110 ,  112 , and finally through an opening  113  ( FIGS. 14 ,  15  and  17 C) formed in movable jaw portion  98 . Suture wire  58  is preferably advanced so that a length  58 A of wire  58  extends approximately 1 centimeter out of the bottom end of movable jaw portion  98  ( FIG. 17C ). In this respect it will be appreciated that, as suture wire  58  leaves fixed jaw portion  96  and engages subject portions  110 ,  112 , the fixed jaw portion&#39;s channel  108 , the cutting bar&#39;s opening  106  and the fixed jaw portion&#39;s channel extension  108 A will support the thin suture wire so as to enable the suture wire to penetrate subject portions  110 ,  112 . 
     Once this has been done, jaw closing actuator  22  is released so as to permit movable jaw portion  98  to return to its “open” position relative to fixed jaw portion  96 , and then wire advance button  20  is used to pay out additional suture wire  58  as the distal end of suturing instrument  10  is stepped back (e.g., by about a centimeter or so) from subject portions  110 ,  112  ( FIG. 17D ). 
     Then jaw closing actuator  22  is used to move jaw portion  98  back into engagement with fixed jaw portion  96  once more ( FIG. 17E ). 
     Next, left-thumb-actuated rotation button  26 , or right-thumb-actuated rotation button  28 , is used to rotate shaft  16  and hence end effector  18 . This causes suture wire  58  to twist on itself, initially creating a relatively large loop  116  ( FIG. 17F ) of suture wire  58  extending from subject portions  110 ,  112  toward suturing instrument  10 . However, as rotation button  26  and/or rotation button  28  is used to rotate shaft  16  (and hence end effector  18 ) more and more, the loop  116  of suture material will progressively close down ( FIG. 17G ) so as to form a tight binder for subject portions  110 ,  112 . In this respect it will be appreciated that the longer the period of time that end effector  18  is rotated, the greater the amount of twisting of suture wire  58 , and the greater the force holding subject portions  110 ,  112 . In this respect it will also be appreciated that suture wire  58  is preferably carefully selected with respect to its flexibility relative to the strength of subject portions  110 ,  112 . In particular, suture wire  58  is chosen so as to have a flexibility such that the suture wire will twist, and loop  116  will close down, before subject portions  110 ,  112  will undergo substantial deformation and/or tearing. By way of example but not limitation, in practice, it has been found that 0.005 inch diameter stainless steel wire can be used with most types of mammalian tissue such that the suture wire can be twisted closed without causing substantial deformation and/or tearing of the tissue. 
     Once suture wire  58  has been tightened to the desired degree, rotation of shaft  16  and end effector  18  is stopped, i.e., by releasing button  26  or button  28 . Then wire cutting actuator  24  is depressed (e.g., it is pulled back toward handle  14 ) so as to pull cutting bar  104  proximally and thereby sever the suture wire  58  as the suture wire emerges from the fixed jaw portion&#39;s channel  108  and enters the cutting bar&#39;s opening  106  ( FIG. 17H  and  FIG. 15 ). This action separates the deployed suture wire extending through subject portions  110 ,  112  from the suture wire remaining in wire supply cartridge  30 , wire guide  76  and the fixed jaw portion&#39;s channel  108 . 
     Then wire cutting actuator  24  is released, allowing biasing spring  69  to return cutting bar  104  to return to its distal position, and then jaw closing actuator  22  is released, allowing movable jaw portion  98  to move away from fixed jaw portion  96 . Suturing instrument  10  may then be removed from subject portions  110 ,  112  which action will pull wire length  58 A from movable jaw portion  98  ( FIG. 171 ). 
     The deployed suture wire  58  may then be pressed down flat against subject portions  110 ,  112 , or rounded into a ball, or otherwise operated upon, so as to reduce the profile of, or reduce the tendency to snag on, the deployed suture wire ( FIG. 17J ). 
     It will be appreciated that suturing instrument  10  will have application in a broad range of different suturing operations. More particularly, it will be appreciated that suturing instrument  10  will have application in both “open” and “closed” surgical procedures, with the former including, but not limited to, large entry procedures, relatively shallow procedures, and surface procedures; and with the latter including, but not limited to, surgical procedures where access is gained to an interior structure through the use of a cannula, and surgical procedures where access is gained directly to an internal body cavity without the use of a cannula, e.g., such as a procedure conducted within the colon or the esophagus. 
     It will also be appreciated that suturing instrument  10  will have application where two portions of tissue must be attached to one another (e.g., where two severed pieces of tissue must be re-attached to one another, or where two separate pieces of tissue must be attached to one another, or where two sections of a single piece of tissue must be approximated to one another), and where an object must be attached to the patient (e.g., where surgical mesh must be attached to the patient&#39;s abdominal wall during hernia repair surgery, etc.). 
     Among other things, it is believed that suturing instrument  10  will have particular application in the areas of general laparoscopic surgery, general thoracic surgery, cardiac surgery, general intestinal surgery, vascular surgery, skin surgery and plastic surgery. 
     Looking next at  FIGS. 18 and 19 , it will be seen that where the fixed jaw portion&#39;s channel  108  is disposed so as to be substantially aligned with the center of cutting bar  104  ( FIG. 18 ), suture wire  58  will be cut with a relatively flat leading end  58 B ( FIG. 19 ). However, it has sometimes been found helpful to provide suture wire  58  with a relatively sharp leading point. Such a leading point can help open the subject for the following portion of the suture wire. In addition, such a leading point can help the suture wire penetrate the subject with a substantially straight path, so that the suture wire will reliably enter the movable jaw portion&#39;s opening  113 . To this end, it has been found that moving the fixed jaw portion&#39;s channel  108  off-center relative to cutting bar  104  ( FIG. 20 ) will cause the leading end  58 B of suture wire  58  to be formed with a relatively sharp tip  58 C ( FIG. 21 ). 
     It is also possible to use suturing instrument  10  to ligate a subject rather than to pass a suture through the subject. For example, suturing instrument  10  might be used to ligate a blood vessel with suture wire  58 . In this case, suturing instrument  10  is deployed so that suture wire  58  will pass around the far side of the subject, rather than through the subject as in the case of the suturing operation of the type described above. 
     By way of example but not limitation, in a typical ligating operation, movable jaw portion  98  is first opened relative to fixed jaw portion  96 . Then suturing instrument  10  is positioned about the subject so that when movable jaw portion  98  is thereafter closed toward fixed jaw portion  96 , the fixed jaw portion&#39;s channel  108  and the movable jaw portion&#39;s opening  113  will both lie on the far side of the subject. The movable jaw portion  98  is then closed against the fixed jaw portion  96 , and suture wire  58  is passed from fixed jaw portion  96  to movable jaw portion  98 , i.e., around the far side of the subject. The movable jaw portion  98  is then opened, and suture wire  58  is payed out as the instrument is stepped back from the subject. Then the movable jaw portion  98  is again closed against the fixed jaw portion  96 . The shaft of the instrument is then rotated so as to form, and then close down, the ligating loop. Then cutting bar  104  is activated so as to cut the ligating loop from the remainder of the suture wire still in the tool, the movable jaw member  98  is opened, and the instrument is withdrawn from the surgical site. The deployed suture wire  58  may then be pressed down flat against the subject, or rounded into a ball, or otherwise operated upon, so as to reduce the profile of, or reduce the tendency to snag on, the deployed suture wire. As will be appreciated by a person skilled in the art, where instrument  10  is to be used for ligating purposes, fixed jaw portion  96  and movable jaw portion  98  might be formed with a greater longitudinal length so as to facilitate passing the suture wire around the far side of the subject. Furthermore, movable jaw member  98  might be formed with a recess, intermediate its jaw linkage pin  100  ( FIG. 15 ) and its opening  113 , for accommodating the subject, whereby to prevent compressing the subject when movable jaw member  98  is moved into engagement with fixed jaw member  96 . 
     Suture wire  58  may comprise a wire formed out of a metal or any other suitable material having the required flexibility and stiffness. By way of example but not limitation, suture wire  58  may comprise stainless steel, titanium, tantalum, etc. 
     If desired, suture wire  58  may also be coated with various active agents. For example, suture wire  58  may be coated with an anti-inflammatory agent, or an anti-coagulant agent, or an antibiotic, or a radioactive agent, etc. 
     Looking next at  FIG. 22 , it is also possible to impart ultrasound energy to the wire in order to make tissue penetration easier. More particularly, because of the small cross-sectional area of the wire and the propensity for the wire to buckle when axially loaded, it is beneficial to be able to advance the wire into tissue with a minimum of load. This can be achieved by appropriately applying ultrasound energy to the wire. 
     A piezoelectric element  200  is placed at the outside radius of the wire guide path  108  at the right angle bend in the fixed jaw portion  96  just before where the wire enters the tissue. The piezoelectric element  200  vibrates at a position along this bend such that it supports the wire in completing the turn but also imparts a component of displacement in the direction of the tissue. Displacement of this kind at ultrasonic frequencies, in addition to the existing wire driving means, would cause the tip of the wire to penetrate the tissue using less force. In addition to reducing the tendency for outright wire buckling, lowering the wire loads will also allow the wire penetration to proceed in a straighter path. 
     Looking next at  FIG. 23A , it will be seen that, in some circumstances, the suture wire  58  may exit fixed jaw portion  96  with a curvature, due to the fact that suture wire  58  follows curved channel  108  in fixed jaw portion  96 . In some cases this curvature in the suture wire  58  may be quite modest, so that it may be effectively ignored. However, in other circumstances, this curvature might be large enough to cause the suture wire advancing out of fixed jaw portion  96  to miss the target opening  113  in movable jaw portion  98 . In this case the curvature in suture wire  58  can present a significant problem. However, and looking now at  FIG. 23B , it has been found that the profile of the cutting bar&#39;s opening  106  may be modified so as to provide a deflecting die which will counteract undesirable curvature in the suture wire and return the suture wire to a straight path as the suture wire exits fixed jaw portion  96 . Alternatively, the profile of the fixed jaw portion&#39;s channel  108  may be modified, adjacent to cutting bar  104 , so as to provide a similar deflecting die which will counteract undesirable curvature in the suture wire and return the suture wire to a straight path as the suture wire exits fixed jaw portion  96 . Futhermore, and looking now at  FIG. 23C , the mouth of the movable jaw portion&#39;s opening  113  may be enlarged to help capture a suture wire deviating from a straight path. 
     Looking next at  FIG. 24 , it will be seen that one or more legs  300  may be provided on suturing instrument  10 , wherein legs  300  help stabilize the tissue during suturing. 
     And looking next at  FIG. 25 , it will be seen that a grasper  400 , comprising jaws  405  and  410 , may be added to suturing instrument  10  to help stabilize the tissue during suturing. 
     If desired, the end effector  18  of suturing instrument  10  may be constructed so as to have two movable, opposing jaws, rather than one fixed jaw and one movable jaw as described above. 
     Also, if desired, shaft rotation motor  60  and thumb buttons  26 ,  28  may be configured so that depressing one button (e.g., button  26 ) will cause end effector  18  to rotate in one direction (e.g., clockwise), and depressing the other button (e.g., button  28 ) will cause end effector  18  to rotate in the opposite direction (e.g., counterclockwise). 
     Significantly, it has been found that the present invention has particular application in a novel procedure to address gastroesophogeal reflux disease (GERD), among others. 
     More particularly, with this novel procedure, suturing instrument  10  may be used to gather tissue below the stomach&#39;s lower esophageal sphincter (LES) so as to improve its function and thereby reduce the symptoms of GERD. In one preferred form of the invention, and looking now at  FIGS. 26–29 , suturing instrument  10  is inserted into the interior of a patient&#39;s stomach so that its end effector  18  is located adjacent to the wall of the LES ( FIG. 26 ), jaw portions  96  and  98  are used to gather together two spaced sections  110 ,  112  of the wall of the LES ( FIG. 27 ), and then suture wire  58  is used to secure together, in the manner previously described, the gathered-together portions of the stomach wall below the LES ( FIGS. 28 and 29 ). The foregoing steps may be repeated as many times as is necessary to adequately gather the stomach wall below the patient&#39;s LES and thereby improve its function and reduce the symptoms of GERD. 
     In this respect it has also been found that it may be useful to construct suturing instrument  10  in certain ways, or to modify suturing instrument  10  in certain ways, so as to facilitate its use in the aforementioned GERD procedure, among others. 
     Thus, for example, it has been found that the aforementioned GERD procedure may be advantageously carried out by approaching the LES through the esophagus, preferably through the working lumen of an endoscope. To this end, suturing instrument  10  is preferably formed so as to be flexible along its length. This may be accomplished by forming shaft  16  ( FIGS. 1 and 14 ) out of a flexible material, and by forming its internal components (e.g., jaw linkage  68 , wire cutting linkage  72  and wire guide  76 ) out of flexible elements. By way of example but not limitation, shaft  16  may be formed with a plastic, metal-reinforced construction, such as a construction of the sort used to form flexible endoscopes; jaw linkage  68  and wire cutting linkage  72  may be formed out of flexible metal rods; and wire guide  76  may be formed out of polytetrafluoroethylene (PTFE). Alternatively, and looking next at  FIG. 29A , a portion of shaft  16  may be removed, e.g., at A, so as to leave a smaller, flexible spine B connecting a distal section C with a proximal section D. If desired, spine B may be formed integral with, and out of the same material as, distal section C and proximal section D; alternatively, spine section B may be formed out of another material, e.g., Nitinol. Furthermore, if desired, the connecting section B could be located along the center axis of shaft  16 , e.g., by making it out of a separate piece of material connected to both distal section C and proximal portion D. This latter construction can be particularly advantageous in that it can be relatively stiff in torsion as to transmit torque, yet flexible in bending along its length. 
     Furthermore, in using suturing instrument  10  in the aforementioned GERD procedure, it has been found that the LES can frequently be difficult to grasp and draw together, due to (i) the angle of attack to the tissue, (ii) the slippery nature of the tissue, and (iii) the variable tones of the tissue. As a result, it has also been found that it can be helpful to provide two movable jaw portions for gripping the tissue. 
     More particularly, and looking now at  FIGS. 30–39 , two movable jaw portions  96 A,  98 A may be provided at the distal end of shaft  16 . Jaw portions  96 A,  98 A are pivotally pinned, via pivot pins  100 A and  100 B, respectively, to an outer yoke  16 A secured to the distal end of shaft  16  ( FIG. 31 ). At the same time, jaw portions  96 A,  98 A are also pivotally pinned, via pivot pins  100 C riding in a slot  100 D, to an inner yoke  16 B ( FIG. 33 ). Inner yoke  16 B is movably disposed within outer yoke  16 A and is secured to the end of jaw linkage  68 A. As a result of this construction, when inner yoke  16 B is moved distally by jaw linkage  68 A, jaw portions  96 A,  98 A will open relative to one another ( FIG. 31 ); and when inner yoke  16 B is moved proximally by jaw linkage  68 A, jaw portions  96 A,  98 A will close together ( FIG. 37 ). The foregoing construction is highly advantageous for several reasons, among others: (i) by providing two movable jaw portions, the mouth of the suturing instrument can be enlarged so as to facilitate gripping and drawing together tissue, e.g., such as in the aforementioned GERD procedure, and (ii) by using a single, movable inner yoke  16 B to open and close jaw portions  96 A,  98 A pinned to a fixed outer yoke  16 A, the two jaw portions can be made to reliably open and close to a corresponding and symmetrical extent, thereby ensuring uniform mouth operation at all times. 
     In addition to the foregoing, jaw portions  96 A,  98 A are preferably provided with offset distal teeth (or fangs)  96 B,  98 B, respectively ( FIG. 30 ). These teeth (or fangs)  96 B,  98 B enhance the ability of the jaw portions to grip tissue, particularly hard-to-grip tissue such as the LES during the aforementioned GERD procedure. 
     Inasmuch as jaw portions  96 A,  98 A both move, it can also be advantageous to modify certain aspects of the suturing instrument from the construction previously disclosed. More particularly, with the suturing instrument disclosed above, jaw portion  96 , which delivers suture wire  58  to the tissue, is fixed relative to shaft  16 , and wire guide  76  extends linearly into jaw portion  96  and preferably confronts a stop shoulder ( FIG. 14 ). However, with the embodiment disclosed in  FIGS. 30–39 , both jaw portion  96 A and jaw portion  98 A move relative to shaft  16 . As a result, with the construction of  FIGS. 30–39 , it is preferred that the distal end of wire guide  76 A ( FIG. 39 ) terminate in jaw portion  96 A in a slightly different manner so that suture wire  58  can be reliably guided into the wire guide path in jaw portion  96 A. At the same time, inasmuch as it is desirable to increase the radius of curvature imposed on suture wire  58 , it is preferred that wire guide  76 A be outboard of pivot pin  100 A, so that wire guide  76 A can “cut the corner” when jaw portion  96 A is in its open position ( FIG. 33 ). To this end, since the distal end of wire guide  76 A may move slightly relative to jaw portion  96 A depending on the pivotal position of jaw portion  96 A, it is preferred that the distal end of wire guide  76 A be provided with a flange  76 B ( FIG. 33 ) which is received in a slot  96 C which is formed in jaw portion  96 A, whereby wire guide  76 A can be attached to jaw portion  96 A with a floating engagement. 
     In order to prevent cutting bar  104  and/or wire cutting linkage  72  from impeding the opening and/or closing of jaw portion  96 A, it is preferred that cutting bar  104  and wire cutting linkage  72  be sized so that they can both be fully withdrawn from jaw portion  96 A when cutting bar  104  is in its withdrawn (i.e., proximal) position. And in one preferred form of the invention, cutting bar  104  and its associated wire cutting linkage  72  are replaced by a single cutting rod  104 A ( FIGS. 37 and 38 ) which extends from housing  12  to the end of shaft  12 . The distal end of cutting rod  104 A is used to selectively intrude across the wire guide path formed in jaw portion  96 A so as to sever suture wire deployed from the suturing instrument. Cutting rod  104 A is preferably formed out of a flexible material, such that cutting rod  104 A can extend into jaw portion  96 A even when intervening tissue should prevent full closure of jaw portion  96 A and  98 A. 
     In the aforementioned GERD procedure, it has been found that where the LES is accessed through the esophagus, wire must be driven a fairly long distance, e.g., from an area proximal to the proximal end of the endoscope (typically located a significant distance from the patient&#39;s mouth) to an area distal to the distal end of the endoscope (typically located at the LES). In practice, this is typically a distance of approximately 3 feet for a gastroscope (and up to 5 feet long for a colonoscope, when doing colon procedures, see below). However, it has been found that it can be difficult to drive the suture wire such a long distance. This is because the suture wire is typically chosen for its penetrating, twisting and cutting characteristics, and this typically means using relatively soft wire, e.g., 316L stainless steel wire having a tensile strength of 160 kpsi. Thus, in one form of the invention, it has been found helpful to supply suture wire  59 A ( FIG. 40 ) of two differing characteristics: (i) a softer distal wire portion  59 B optimized for tissue penetration, twisting and cutting, and a harder proximal wire portion  59 C optimized for driving. By way of example, while distal wire portion  59 B might comprise 316L stainless steel with a tensile strength of 160 kpsi, proximal wire portion  59 C might comprise 304 stainless steel with a tensile strength of 430 kpsi. Distal wire portion  59 B might be incorporated with wire supply cartridge  30  during manufacture, or distal wire portion  59 B might be added to wire supply cartridge  30  and/or suturing instrument  10  after proximal wire portion  59 C has been installed in wire supply cartridge  30 . Distal wire portion  59 B may or may not be secured to proximal wire portion  59 C. 
     It should also be appreciated that while suturing instrument  10  uses the aforementioned drive barrel assembly  80  ( FIG. 8 ) to drive suture wire  58  (or suture wire  58 A), other apparatus may be used to drive the suture wire, e.g., a wire drive mechanism such as is disclosed in pending U.S. patent application Ser. No. 10/051,322, filed Jan. 18, 2002 by Frederic P. Field et al. for SURGICAL SUTURING INSTRUMENT AND METHOD OF USE; or a wire drive mechanism such as is disclosed in pending U.S. patent application Ser. No. 10/039,601, filed Oct. 19, 2001 by Frederic P. Field et al. for SURGICAL SUTURING INSTRUMENT AND METHOD OF USE; or a wire drive mechanism such as is disclosed in pending U.S. patent application Ser. No. 10/082,510, filed Oct. 19, 2001 by Frederic P. Field et al. for SURGICAL SUTURING INSTRUMENT AND METHOD OF USE; or any other wire drive mechanism consistent with the present invention. The three aforementioned patent applications are hereby incorporated herein by reference. 
     The foregoing constructions and/or modifications have been found to be particularly advantageous for effecting the aforementioned GERD procedure, particularly when accessing the LES through the esophagus. However, it should also be appreciated that one or more of these constructions and/or modifications may also be applicable to other surgical procedures including, but not limited to, a gastric bypass procedure; hemostasis for peptic ulcer disease; closing perforations within the gastrointestinal tract; fixing stents within the gastrointestinal tract or elsewhere in the body; fixing GERD monitoring apparatus in place within the gastrointestinal tract; closing endoscopic mucosal resection (EMR) sites within the stomach and/or the colon; and in other surgical procedures which will be obvious to those skilled in the art in light of the present disclosure. 
     Modifications 
     It will be appreciated by those skilled in the art that numerous modifications and variations may be made to the above-disclosed embodiments without departing from the spirit and scope of the present invention.

Technology Classification (CPC): 0