Patent Publication Number: US-2023157683-A1

Title: Suturing instrument

Description:
FIELD OF THE INVENTION 
     The present invention relates to a suturing instrument, for example, a suturing instrument for suturing two portions of a human or animal body together, and in particular, though not limited to a suturing instrument for suturing two portions of a lumen, vessel or organ together within the human or animal body. 
     BACKGROUND TO THE INVENTION 
     In the carrying out of minimally invasive surgery, for example, in the carrying out of surgery using an endoscope or a laparoscope, whereby the endoscope or laparoscope is introduced into the interior of a lumen, vessel, organ or cavity in the human or animal body, and where such a lumen, vessel or organ is to be sutured, in general, it is necessary to suture the lumen, vessel or organ internally within the interior of the lumen, vessel or organ. For example, in the carrying out of a bariatric procedure, such as an endoscopic sleeve gastroplasty procedure on a subject, in which a gastric sleeve is formed passing through the stomach of the subject, an endoscope is entered orally through the oesophagus into the stomach of the subject. A suturing instrument is entered into the stomach of the subject through an instrument bore extending through the endoscope for suturing the opposite walls of the stomach together in order to form the gastric sleeve extending through the stomach of the subject. 
     Another procedure in which it is necessary to suture a lumen, vessel or organ within the interior of the lumen, vessel or organ is in a procedure for everting a polyp in the colon of a subject in order to facilitate subsequent severing of the everted polyp from the colon wall on the external side thereof. Other procedures which require the suturing of a lumen, vessel or organ interiorly in the lumen, vessel or organ, are procedures which are carried out laparoscopically, whereby a laparoscope is entered into a cavity in the human or animal subject, for example, the abdominal cavity, and the laparoscope is then entered from the abdominal cavity into the lumen, vessel or organ in which the procedure is to be carried out. In such cases, a suturing instrument is entered into the lumen, vessel or organ through an instrument bore in the endoscope or the laparoscope, and suturing of the lumen, vessel or organ is carried out by the suturing instrument internally within the lumen, vessel or organ. 
     Additionally, in laparoscopic surgery it may be necessary to suture a lumen, vessel or organ externally of the lumen, vessel or organ in a cavity, in which the lumen, vessel or organ is located, for example, a lumen, vessel or organ in the peritoneal cavity. In such cases a laparoscope is entered into the peritoneal cavity and a suturing instrument is then entered through an instrument bore in the laparoscope into the peritoneal cavity. 
     However, known suturing instruments suffer from various disadvantages. For example, in suturing instruments known heretofore, it is necessary to withdraw the suturing instrument after each suture has been inserted in order to recharge the suturing instrument with the next suture. This is inconvenient, and is also time consuming, which in turn results in unnecessary increase in the time required to carry out the procedure, and in turn the time during which a subject must remain under an anaesthetic. 
     There is therefore a need for a suturing instrument which addresses this problem. 
     SUMMARY OF THE INVENTION 
     According to the invention there is provided a suturing instrument comprising:
         an elongated cannula extending from a proximal end to a distal end and having a suture bore extending longitudinally therethrough for accommodating a plurality of sutures therein, the cannula terminating at its distal end in a distal piercing tip,   the sutures being of the type comprising:
           a suture thread terminating at its opposite ends in respective   anchor elements,   
           the suture thread being configured to form
           a loop extending from one anchor element to the other one of the anchor elements, and   a cinch clip located on the loop of the suture thread and being urgeable along the loop towards the anchor elements for progressively reducing the effective length of the suture thread between the anchor elements,   
           the suture bore of the cannula being configured for accommodating at least a part of the sutures therein with at least the anchor elements of the sutures being located in the suture bore, and   a pusher element for selectively and sequentially discharging the suture from the suture bore through the distal piercing tip of the cannula, and for selectively and sequentially discharging the anchor elements of each suture through the distal piercing tip of the cannula.       

     In one embodiment of the invention the pusher element is slideable in the suture bore. 
     In one embodiment of the invention the pusher element extends into the suture bore from the proximal end of the cannula. 
     In another embodiment of the invention an urging means is provided for urging the pusher element distally in the suture bore for selectively and sequentially discharging the anchor elements from the suture bore. 
     In one embodiment of the invention the suture bore is configured for accommodating the anchor elements of each suture aligned with each other, and preferably, for accommodating the anchor elements of the respective sutures aligned with each other, and advantageously, for accommodating the anchor elements aligned with the suture bore. 
     In another embodiment of the invention the suture bore is configured for accommodating elongated anchor elements of the respective sutures, and preferably, for accommodating the elongated anchor elements aligned longitudinally with each other. 
     In another embodiment of the invention the suture bore is configured for accommodating the anchor elements of the respective sutures aligned end-to-end with each other. 
     In another embodiment of the invention the suture bore of the cannula is configured for accommodating the cinch clips of the respective sutures, and preferably, the suture bore is configured for accommodating elongated cinch clips of the respective sutures, and preferably, the suture bore is configured to accommodate the cinch clips of the respective sutures longitudinally aligned with the suture bore, and preferably, longitudinally aligned with each other in the suture bore. 
     In another embodiment of the invention the suture bore is configured to accommodate the cinch clips aligned with the anchor elements of the respective sutures. Preferably, the suture bore is configured for accommodating the cinch clips of the respective sutures aligned end-to-end with adjacent anchor elements. 
     In another embodiment of the invention the suture bore is configured to accommodate the cinch clip of each suture located between the anchor elements of the corresponding suture. 
     In an alternative embodiment of the invention the suture bore is configured for accommodating the cinch clip of each suture located distally relative to the anchor elements of the corresponding suture. 
     In a further alternative embodiment of the invention the suture bore is configured for accommodating the cinch clip of each suture located proximally relative to the anchor elements of the corresponding suture. 
     In another embodiment of the invention the pusher element is configured to selectively and sequentially discharge the cinch clip and the anchor elements of each suture, from the suture bore through the distal piercing tip of the cannula. 
     In another embodiment of the invention an elongated longitudinal slot extends longitudinally along the cannula and through the cannula from an outer side to an inner side of the cannula wall for accommodating the suture threads of the respective sutures therethrough. 
     In another embodiment of the invention the longitudinal slot extends into the cannula from the distal piercing portion thereof. 
     In one embodiment of the invention the cannula terminates in a distal piercing portion extending proximally from the distal piercing tip, and preferably, the distal piercing portion is substantially rigid for piercing through tissue. 
     In another embodiment of the invention the cannula comprises an intermediate portion extending from the distal piercing portion to a proximal portion adjacent the proximal end of the cannula. Preferably, the intermediate portion of the cannula is configured to be flexible and bendable for flexing and bending to accommodate manoeuvring of the suturing instrument through bends and curves through which the suturing instrument must be passed to gain access to the lumen, vessel or organ. 
     In one embodiment of the invention an interrupted helical slot extends through the peripheral wall of the intermediate portion of the cannula, and the interrupted helical slot extends along the intermediate portion thereof. Preferably, the interrupted helical slot extends the length of the intermediate portion of the cannula from the distal piercing portion to the proximal portion thereof. 
     In one embodiment of the invention the interrupted helical slot comprises a plurality of slot sections extending partly around the peripheral wall of the intermediate portion of the cannula with interrupted sections of the interrupted helical slot located between adjacent pairs of the slot sections. 
     In one embodiment of the invention the interrupted helical slot is of pitch lying in the range of 0.8 mm to 1.5 mm, and preferably, the pitch of the interrupted helical slot lies in the range of 1.1 mm to 1.3 mm, and advantageously, the pitch of the interrupted helical slot is approximately 1.2 mm. 
     In another embodiment of the invention the kerf width of the helical slot is approximately 0.025 mm. 
     In one embodiment of the invention each slot section extends partly around the intermediate portion of the cannula an angular distance in the range of 1700 to 350°. Preferably, each slot section extends partly around the intermediate portion of the cannula an angular distance in the range of 2100 to 290°. 
     Advantageously, each slot section extends partly around the intermediate portion of the cannula an angular distance in the range of 2200 to 260°. Preferably, each slot section extends partly around the intermediate portion of the cannula an angular distance of approximately 240°. 
     In another embodiment of the invention each interrupted section of the interrupted helical slot extends partly around the intermediate portion of the cannula an angular distance in the range of 100 to 190°. Preferably, each interrupted section of the interrupted helical slot extends partly around the intermediate portion of the cannula an angular distance in the range of 20° to 130°. Advantageously, each interrupted section of the interrupted helical slot extends partly around the intermediate portion of the cannula an angular distance in the range of 30° to 70°, and ideally, each interrupted section of the interrupted helical slot extends partly around the intermediate portion of the cannula an angular distance of approximately 40°. 
     In another embodiment of the invention the outer diameter of the cannula lies in the range of 0.7 mm to 1.8 mm, and preferably, the outer diameter of the cannula is approximately 1.27 mm. 
     In one embodiment of the invention the wall thickness of the cannula lies in the range of 0.05 mm to 0.3 mm, and preferably, the wall thickness of the cannula is approximately 0.0762 mm. 
     In another embodiment of the invention the suture accommodating bore of the cannula is of transverse cross-section just slightly greater than the maximum transverse cross-sectional dimension of the anchor elements or the cinch clip, whichever of which is of the greatest maximum transverse cross-section. 
     In another embodiment of the invention the structure bore of the cannula is of transverse cross-section to slideably accommodate the sutures therein with the suture thread extending along the side of each anchor element, and preferably, the suture bore of the cannula is of transverse cross-section to slideably accommodate the sutures with the suture thread extending along the side of the cinch clips. 
     In one embodiment of the invention a retaining means is provided for releasably retaining the sutures in the suture bore, and preferably, the retaining means is located adjacent the distal end of the cannula, and advantageously, the retaining means is located just slightly spaced apart longitudinally from the distal piercing tip. 
     In one embodiment of the invention the retaining means comprises a retaining projection extending inwardly into the suture bore, preferably the retaining projection is formed by inwardly impressing a dimple into the cannula wall from the outer surface thereof, and preferably, a portion of the cannula adjacent which the dimple is impressed into the wall of the cannula is configured to be resilient to permit outward movement of the portion of the cannula from which the retaining projection projects, and in turn outward movement of the retaining projection, in order to accommodate passage of the distal most one of the anchor elements or the cinch clip of the distal most suture in the suture bore past the retaining projection in response to distal urging thereof by the pusher element. Preferably, the resilience of the portion of the cannula from which the retaining projection projects is such as to return it to its undisturbed state for in turn returning the retaining projection to engage and retain captive the next distal most one of the anchor elements or the cinch clip of the distal most suture in the suture bore. 
     In another embodiment of the invention the urging means is configured for urging the anchor elements and the cinch clips of the respective sutures from the suture bore through the distal piercing tip of the cannula. 
     Preferably, the urging means is configured to urge the pusher element distally selectively and sequentially through a plurality of respective predefined distances for selectively and sequentially discharging the ones of the anchor elements and the cinch clip of each suture in the suture bore of the cannula through the distal piercing tip of the cannula. 
     In one embodiment of the invention the distance through which the urging means is configured to urge the pusher element distally in the suture bore for discharging each one of the anchor elements and/or each one of the cinch clips corresponds to the length of the distal most one of the anchor elements and/or the cinch clip of the distal most suture in the suture bore, and advantageously, the distance through which the urging means is configured to urge the pusher element distally in the suture bore for discharging each one of the anchor elements and/or each one of the cinch clips is substantially equal to the length of the distal most one of the anchor elements and/or the cinch clip of the distal most suture in the suture bore of the cannula. 
     In another embodiment of the invention the urging means is configured to urge the pusher element distally in the suture bore for discharging each one of the anchor elements and/or the cinch clips from the suture bore respective first, second and third predefined distances substantially equal to the respective lengths of the anchor elements and the length of the cinch clip. 
     In one embodiment of the invention the first and second predefined distance are of similar length, and preferably, are of equal length, and advantageously, the third predefined distance is of a substantially similar length to the first predefined distance, and advantageously, the third predefined distance is of length substantially equal to the first predefined distance. 
     In one embodiment of the invention the urging means comprises a linear motor, and in another embodiment of the invention the urging means comprises a rotary stepper motor. 
     In one embodiment of the invention a transmission means is provided for transmitting drive from the urging means to the pusher element. 
     In a further embodiment of the invention a controller is provided for controlling the operation of the urging means, and preferably, the controller is responsive to an activation signal for operating the urging means to urge the pusher element distally in the suture bore through each one of the predefined distances. 
     Preferably, the controller is responsive to the activation signal for operating the urging means to urge the pusher element distally in the suture bore through the first predefined distance for urging a first one of the anchor elements of the sutures from the suture bore of the cannula through the distal piercing tip thereof. 
     In another embodiment of the invention the controller is responsive to the activation signal for operating the urging means to urge the pusher element distally in the suture bore through the second predefined distance for discharging a second one of the anchor elements of the sutures from the suture bore of the cannula through the distal piercing tip thereof. 
     In a further embodiment of the invention the controller is responsive to the activation signal for urging the pusher element distally in the suture bore through the third predefined distance for discharging the cinch clip of the sutures from the suture bore of the cannula through the distal piercing tip thereof. 
     In one embodiment of the invention the activation signal is derived from a human operable switch. 
     In one embodiment of the invention the human operable switch comprises a foot operable switch, and preferably, an electrical switch operable by a foot pedal. 
     In another embodiment of the invention the human operable switch comprises a manually operable switch. 
     In one embodiment of the invention the controller is programmed to operate the urging means to urge the distal most pusher element distally in the suture bore one of a first predefined distance of the predefined distances to discharge one of the anchor elements adjacent the distal piercing tip from the suture bore through the distal piercing tip. 
     In another embodiment of the invention the controller is programmed to operate the urging means to urge the pusher element distally in the suture bore one of a second predefined distance of the predefined distances to discharge one of the cinch clips adjacent the distal piercing tip from the suture bore through the distal piercing tip. 
     In one embodiment of the invention the anchor elements of the respective sutures are of the same length. 
     In another embodiment of the invention the cinch clips of the respective sutures are of the same length. 
     In a further embodiment of the invention the cinch clips of the respective sutures are of the same length as the anchor elements thereof. 
     In one embodiment of the invention the second predefined distance is equal to the first predefined distance, and in another embodiment of the invention the third predefined distance is equal to the first predefined distance. 
     In another embodiment of the invention the controller is responsive to each activation signal for operating the urging means to urge the pusher element distally through one of the predefined distances. 
     In one embodiment of the invention the controller comprises a signal processor, and preferably, a programmable signal processor, and advantageously, the signal processor comprises a microcontroller. 
     In one embodiment of the invention the signal processor is programmed to count the anchor elements and/or the cinch clips, as the case may be, as the anchor elements and the cinch clips are being discharged from the suture bore, in order that the signal processor can determine the identity of the distal most one of the anchor elements and/or the cinch clip in the suture bore of the cannula. 
     In another embodiment of the invention a sensor is provided for detecting the distal most one of the anchor elements and the cinch clip of the distal most suture in the suture bore, the sensor being configured to produce a signal indicative of the one of the anchor element and the cinch clip which is distal most in the suture bore. 
     In one embodiment of the invention the sensor is located adjacent the distal end of the cannula, and preferably, the sensor is located in or on the cannula slightly spaced apart longitudinally from the distal piercing tip thereof. 
     In another embodiment of the invention the suturing instrument comprises an outer sleeve extending from a proximal end to a distal end and having a cannula bore configured for accommodating the cannula therein. 
     In one embodiment of the invention the cannula is slideable within the cannula bore. 
     In another embodiment of the invention the cannula is of a length greater than the length of the outer sleeve. 
     In an alternative embodiment of the invention the outer sleeve is of a length greater than the length of the cannula. 
     In one embodiment of the invention the outer sleeve terminates adjacent the proximal end thereof in a primary handle, and advantageously, the cannula terminates adjacent the proximal end thereof in a secondary handle. Preferably, the secondary handle is slideable relative to the primary handle for urging the cannula distally and proximally for urging the cannula distally through the distal end of the outer sleeve for urging the distal piercing tip of the cannula, and for withdrawing the distal piercing tip of the cannula into the outer sleeve through the distal end thereof. 
     The invention also provides the suturing instrument according to the invention comprising a plurality of the sutures located in the suture bore. 
     In one embodiment of the invention each suture comprises a suture thread terminating at its opposite ends in respective anchor elements, the suture thread being configured to form a loop extending from one anchor element to the other one of the anchor elements, and a cinch clip located on the loop of the suture thread and being urgeable along the loop towards the anchor elements for progressively reducing the effective length of the suture thread between the anchor elements. 
     In one embodiment of the invention the sutures are located in the suture bore with the anchor elements of each suture located in the suture bore and aligned with each other, and preferably, with the anchor elements of the respective sutures aligned with each other. 
     In another embodiment of the invention the anchor elements of the respective sutures comprise elongated anchor elements, and preferably, the sutures are located in the suture bore with the elongated anchor elements aligned longitudinally with each other. 
     In another embodiment of the invention the sutures are located in the suture bore with the anchor elements of the respective sutures aligned with each other end-to-end. 
     In another embodiment of the invention the sutures are located in the suture bore with the cinch clips of the respective sutures located in the suture bore. 
     In one embodiment of the invention the cinch clip of each suture comprises an elongated cinch clip, and preferably, the sutures are located in the suture bore with the cinch clips of the respective sutures longitudinally aligned with the suture bore, and preferably, longitudinally aligned with each other in the suture bore. 
     In another embodiment of the invention the sutures are located in the suture bore with the cinch clips aligned with the anchor elements of the respective sutures. Preferably, the sutures are located in the suture bore with the cinch clips of the respective sutures aligned end-to-end with adjacent anchor elements. 
     In another embodiment of the invention the sutures are located in the suture bore with the cinch clip of each suture located between the anchor elements of the corresponding suture. 
     In an alternative embodiment of the invention the sutures are located in the suture bore with the cinch clip of each suture located distally relative to the anchor elements of the corresponding suture. 
     In a further alternative embodiment of the invention the sutures are located in the suture bore with the cinch clip of each suture located proximally relative to the anchor elements of the corresponding suture. 
     In one embodiment of the invention the anchor elements of the respective sutures are of the same length. 
     In another embodiment of the invention the cinch clips of the respective sutures are of the same length. 
     In a further embodiment of the invention the cinch clips of the respective sutures are of the same length as the anchor elements thereof. 
     The invention also provides the suturing instrument comprising a plurality of the sutures located in the suture bore. 
     Additionally, the invention provides a method for suturing two portions of a lumen, vessel or organ in a cavity of the body of a human or animal subject either internally in the interior of the lumen, vessel, organ or cavity, or externally of the lumen, vessel or organ in the interior of the cavity, the method comprising:
         entering the suturing instrument according to the invention charged with a plurality of sutures into the one of the lumen, vessel, organ or cavity in which the suturing is to be carried out,   sequentially inserting the sutures in parts of the portions of the lumen, vessel, organ or cavity to be sutured at spaced apart intervals along the respective portions with the suture thread of each suture extending from the anchor elements thereof through the corresponding parts of a pair thereof of the respective portions of the lumen, vessel or organ, with the parts of each pair thereof being located on the respective portions of the lumen, vessel, organ or cavity, and   tightening the sutures to draw the portions of the lumen, vessel or organ together.       

     In one embodiment of the invention the parts of the portions of the lumen, vessel, organ or cavity are invaginated, and the sutures are inserted in the invaginated parts with the suture thread of each suture extending from the anchor elements thereof through the corresponding pair of the invaginated parts. 
     In one embodiment of the invention each suture is inserted into the corresponding pair of the invaginated parts by the suturing instrument by sequentially urging the distal piercing tip of the cannula through the invaginated parts of the pair thereof,
         each time the cannula has been urged through the respective invaginated parts of one of the pair thereof, the pusher element of the suturing instrument is urged distally in the suture bore of the cannula to discharge the distal most one of the anchor elements of the distal most suture in the suture bore of the cannula through the distal piercing tip of the cannula to deposit that distal most one of the anchor elements on a distal side of the corresponding one of the pair of the invaginated parts, and   withdrawing the cannula from the corresponding one of the invaginated part of the pair thereof with the suture thread extending from the corresponding one of the anchor elements through the corresponding one of the invaginated part of the pair thereof.       

     In another embodiment of the invention when each of the anchor elements of the suture just discharged from the suture bore are located on the distal sides of the invaginated parts of the pair thereof with the suture thread of the suture extending from the respective anchor elements through the corresponding invaginated parts of the pair thereof, and with the suture thread forming a loop extending through the cinch clip of the suture, the suture is tightened by urging the cinch clip along the loop towards the anchor elements to reduce the effective length of the suture thread extending between the anchor elements. 
     In another embodiment of the invention the cinch clip of the distal most suture in the suture bore of the cannula of the suturing instrument is discharged from the suture bore through the distal piercing tip of the cannula in the sequence in which the cinch clip of the distal most suture is located with the anchor elements of the distal most suture in the suture bore. Preferably, the cinch clip is urged from the suture bore by urging the pusher element distally in the suture bore. 
     Preferably, the pusher element is urged distally in the cannula bore through the predefined distance corresponding to the length of the cinch clip for urging the cinch clip from the suture bore. 
     In another embodiment of the invention the distal piercing tip of the cannula is sequentially urged through respective parts of a wall of the lumen, vessel or organ adjacent the portions to be sutured together, and the pusher element is operated to urge the distal most one anchor elements of the distal most suture in the suture bore of the cannula through the distal piercing tip thereof on each part of the pair thereof of the wall of the lumen, vessel or organ being pierced by the cannula to deposit the corresponding anchor element on the distal side of the wall of the lumen, vessel or organ, and the cannula is withdrawn from the corresponding part of the wall of the lumen, vessel or organ with the suture thread extending from the anchor element through the wall of the lumen, vessel or organ. 
     In another embodiment of the invention when each of the anchor elements of the suture just discharged from the suture bore of the cannula are located on the distal sides of the wall adjacent the portions thereof to be sutured together, with the suture thread extending from the respective anchor elements through the portions of the wall to be sutured together, and with the suture thread forming the loop extending through the cinch clip, the suture is tightened by urging the cinch clip along the loop of the suture thread thereof towards the anchor elements for reducing the effective length of the suture thread extending between the anchor elements. 
     In one embodiment of the invention tightening of the sutures commences when the sutures have been inserted in some or all of the pairs of the parts of the wall or through the wall adjacent the portions of the lumen, vessel or organ to be sutured together, and preferably, the sutures are tightened when all of the sutures have been inserted into the respective pairs of the parts or through the wall adjacent the portions of the lumen, vessel or organ. 
     Preferably, the sutures are sequentially tightened. 
     In an alternative embodiment of the invention the sutures are simultaneously tightened. 
     In a further alternative embodiment of the invention each suture is tightened when the suture has been inserted into the corresponding pair of the parts or through the wall adjacent the portions of the lumen, vessel or organ to be sutured together. 
     In one embodiment of the invention the sutures are tightened by a tightening instrument comprising an engagement means or a grabbing means for engaging or grabbing the loop of each suture, urging the loop engaged or grabbed by the engagement means or the grabbing means to urge the cinch clip of the suture against a distal abutment face of an abutment member of the tightening instrument, and urging the loop through the cinch clip to urge the cinch clip along the loop towards the anchor elements of the suture. 
     In another embodiment of the invention the suturing instrument comprises the tightening instrument. 
     In an alternative embodiment of the invention the tightening instrument comprises a separate instrument to that of the suturing instrument. 
     In one embodiment of the invention the suturing is carried out internally in the interior of the lumen, vessel, organ or cavity, and the suturing instrument is entered into the interior of the lumen, vessel, organ or cavity, and preferably, the invaginated parts extend internally into the interior of the lumen, vessel, organ or cavity. 
     In an alternative embodiment of the invention the suturing is carried out externally of the lumen, vessel or organ internally in the cavity in which the lumen, vessel or organ is located, and the suturing instrument is entered into the cavity, and preferably, the invaginated parts extend from the lumen, vessel or organ into the cavity. 
     In another embodiment of the invention each invaginated part of each pair thereof is retained invaginated by a band extending tightly around the invaginated part which preferably, extends around the invaginated part adjacent the root thereof. 
     In another embodiment of the invention the parts are invaginated by an invaginating instrument, which preferably, sucks the parts to be invaginated into a suction recess thereof, and preferably, each invaginated part is retained in the suction recess while the band is being placed on the invaginated part. 
     In another embodiment of the invention the invaginating instrument comprises a multiband ligator. 
     In a further embodiment of the invention the suturing instrument is entered into the lumen, vessel, organ or cavity by an access device, and preferably, the suturing instrument is entered into the lumen, vessel, organ or cavity through an instrument bore in the access device. 
     Alternatively, the suturing instrument is entered into the lumen, vessel, organ or cavity with the suturing instrument extending longitudinally along an outer side of the access device. 
     In one embodiment of the invention the suturing instrument is secured to the outer side of the access device, and preferably, is releasably secured to the outer side of the access device. 
     In another embodiment of the invention the suturing instrument is secured to the outer side of the access device by a plurality of clips spaced apart longitudinally along the suturing instrument and the access device. 
     In another embodiment of the invention the clips are configured to releasably engage the suturing instrument, and in another embodiment of the invention the clips are configured to releasably engage the access device. Advantageously, the clips are configured to releasably engage both the suturing instrument and the access device. 
     In another embodiment of the invention the invaginating instrument is entered into the lumen, vessel, organ or cavity through the access device. 
     In another embodiment of the invention the tightening instrument is entered into the lumen, vessel, organ or cavity through the access device. 
     In one embodiment of the invention the access device comprises an endoscope, and in another embodiment of the invention the access device comprises a laparoscope. 
     In a further embodiment of the invention the organ in which the portions thereof are to be sutured together, comprises a stomach, and preferably, the front and side walls of the stomach are to be sutured together. 
     In one embodiment of the invention the suturing of the stomach is carried out internally in the interior of the stomach, and preferably, the invaginated parts of the stomach extend from the front and rear walls thereof internally into the interior of the stomach. 
     In one embodiment of the invention the suturing of the front and rear walls of the stomach together is carried out to form a gastric sleeve in a sleeve gastroplasty procedure. 
     Preferably, the sleeve gastroplasty procedure comprises an endoscopic sleeve gastroplasty procedure. 
     Advantages of the Invention 
     The advantages of the suturing instrument according to the invention are many. A particularly important advantage of the invention is that the suturing instrument according to the invention enables a plurality of sutures to be inserted in a lumen, vessel or organ, without having to withdraw the suturing instrument to recharge the suturing instrument with a new suture, each time a suture has been inserted in the lumen, vessel or organ. This provides the particularly important advantage in that the time required for suturing within a lumen, vessel or organ with a plurality of sutures is significantly reduced. This advantage is achieved by virtue of the fact that the cannula of the suturing instrument defines an elongated suture accommodating bore, in which a plurality of sutures are stored, and a further advantage of the invention is achieved by the provision of the urging means for urging the pusher element, for in turn selectively and sequentially discharging the sutures from the suture bore, and additionally, for urging the cinch clips of the respective sutures from the suture bore. 
     The provision of the controller for controlling the operation of the urging means for selectively and sequentially urging the sutures from the suture bore, and also for selectively and sequentially urging the anchor elements and the cinch clips of the respective sutures from the suture bore, provides a further advantage, in that the anchor elements and the cinch clips of sutures can be automatically discharged from the suture bore of the cannula by applying an activation signal to the controller. 
     The provision of the controller as a programmable controller enables selective and sequential discharge of the anchor elements and the cinch clips of the respective sutures from the suture bore in cases where the anchor elements of each suture are of different lengths to each other, and additionally, where the cinch clips are of different length to either of the lengths of the anchor elements. Indeed, the controller may be programmed to discharge anchor elements and cinch clips of sutures in which the anchor elements and the cinch clips of the respective sutures are of different lengths from one suture to the next. 
     The invention will be more clearly understood from the following description of some preferred embodiments thereof which are given by way of example only with reference to the accompanying drawings, in which: 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a cross-sectional side elevational view of a suturing instrument according to the invention illustrating a part of the suturing instrument in block representation, 
         FIG.  2    is a cross-sectional side elevational view of a portion of the suturing instrument of  FIG.  1    illustrated in a different state to that of  FIG.  1   , 
         FIG.  3    is a perspective view of a suture for use in the suturing instrument of  FIG.  1   , 
         FIG.  4    is a perspective view of a portion of the suturing instrument of  FIG.  1   , 
         FIG.  5    is an enlarged side elevational view of a detail of the portion of  FIG.  4    of the suturing instrument of  FIG.  1   , 
         FIG.  6    is an enlarged perspective view of another part of the portion of  FIG.  4    of the suturing instrument of  FIG.  1   , 
         FIG.  7    is a cross-sectional angular end elevational view on the line VII-VII of  FIG.  5   , 
         FIGS.  8  to  11    are perspective views of a portion of the suturing instrument of  FIG.  1    illustrated in use suturing parts of a stomach together, 
         FIG.  12    is a perspective view of a greater portion of the stomach of  FIGS.  8  to  11    during the suturing procedure illustrated in  FIGS.  8  to  11   , 
         FIG.  13    is a cross-sectional side elevational view through the stomach of  FIG.  12   , 
         FIG.  14    is a perspective view of the stomach illustrated in  FIG.  12    with the suturing procedure completed, 
         FIG.  15    is a transverse cross-sectional end elevational view of the stomach of  FIG.  12    with the suturing procedure completed, 
         FIG.  16    is a cross-sectional side elevational view of a portion of a suturing instrument according to another embodiment of the invention, 
         FIG.  17    is a cross-sectional side elevational view of the portion of the suturing instrument of  FIG.  16    illustrating the suturing instrument of  FIG.  16    in a different state to that of  FIG.  16   , 
         FIG.  18    is a perspective view of a portion of a suturing instrument according to a further embodiment of the invention, and 
         FIG.  19    is a perspective view of a portion of the suturing instrument of  FIG.  18   . 
     
    
    
     Referring to the drawings and initially to  FIGS.  1  to  7    thereof, there is illustrated a suturing instrument according to the invention indicated generally by the reference numeral  1 . The suturing instrument  1  is particularly suitable for suturing two portions of a lumen, vessel or organ together with the suturing instrument  1  located internally within the interior of the lumen, vessel or organ, and the suturing of the portions of the lumen, vessel or organ to be sutured together are to be sutured from within the lumen, vessel or organ of a human or animal subject, as will be described below with reference to  FIGS.  8  to  15   . The suturing instrument  1  is also suitable for suturing a lumen, vessel or organ, where the suturing is being carried out externally of the lumen, vessel or organ in a cavity, for example, in the peritoneal cavity of a human or animal subject. 
     The suturing instrument  1  comprises an elongated outer sleeve  3  of circular transverse cross-section, extending between a proximal end  4  and a distal end  5 . An elongated cannula accommodating bore  7  of circular transverse cross-section extends longitudinally through the outer sleeve  3  from the proximal end  4  to the distal end  5  for slideably accommodating an elongated cannula  9  extending longitudinally therein. The outer sleeve  3  terminates adjacent the proximal end  4  thereof in a primary handle  6  to which the outer sleeve  3  is rigidly secured. 
     The cannula  9  extends from a proximal end  10  to a distal end  11 , and terminates in its distal end  11  in a distal piercing tip  12 . The cannula  9  is of circular transverse cross-section and is slideable in the cannula bore  7  of the outer sleeve  3 . An elongated suture accommodating bore  14  of circular transverse cross-section extends longitudinally through the cannula  9  from the proximal end  10  to the distal end  11  for accommodating a plurality of sutures  15  therein as will be described below. 
     The cannula  9  is slideable in the outer sleeve  3  from a withdrawn state illustrated in  FIG.  1    to an extended state illustrated in  FIG.  2   . In the withdrawn state of the cannula  9 , the distal piercing tip  12  is located within the distal end  5  of the outer sleeve  3  to protect the distal piercing tip  12 , and also to prevent inadvertent piercing of tissue of the lumen, vessel or organ by the distal piercing tip  12 . In the extended state of the cannula  9 , the distal piercing tip  12  extends outwardly from the distal end  5  of the outer sleeve  3  for piercing tissue into which one of the sutures  15  are to be inserted during suturing of the lumen, vessel or organ. 
     A secondary handle  8  is slideably mounted on the primary handle  6 , and is rigidly connected to the cannula  9  adjacent the proximal end  10  for operating the cannula  9  in the cannula bore  7  of the outer sleeve  3  between the withdrawn state and the extended state. The cannula  9  extends from the proximal end  4  of the outer sleeve  3  to the secondary handle  8  through a bore  16  extending through the primary handle  6 . By urging the secondary handle  8  distally in the direction of the arrow A, relative to the primary handle  6 , the cannula  9  is urged from the withdrawn state within the outer sleeve  3  to the extended state with the distal piercing tip  12  extending distally outwardly from the distal end  5  of the outer sleeve  3 . 
     Before describing the suturing instrument  1  in further detail, one of the sutures  15  will first be described with reference to  FIG.  3   . The sutures  15  are identical to each other. Each suture  15  comprises a suture thread  17  terminating in its opposite ends  18  in respective anchor elements  19 . The anchor elements  19  of each suture  15  comprise respective tubular anchor bars  20  of external circular, substantially constant transverse cross-section of diameter which is less than the diameter of the suture bore  14  of the cannula  9 , so that the anchor bars  20  are slideable within the suture bore  14 . The anchor bars  20  of the anchor elements  19  of the respective sutures  15  are of the same diameter and of the same length. The anchor bars  20  anchor the suture  15  in the respective parts of the lumen, vessel or organ to be sutured together as will be described below. The suture thread  17  is secured in each anchor bar  20  intermediate the respective ends of the anchor bar  20 , and extends from the anchor bars  20  to form a loop  22 . 
     The loop  22  of each suture  15  extends through a corresponding cinch clip  24  which is formed from a tubular member  25 , opposite side walls  26  of which are crimped towards each other at  27 . Top and bottom slots  28  and  29  formed in top and bottom walls  30  and  32 , respectively, of the cinch clip  24  accommodate the loop  22  of the suture thread  17  therethrough. The crimping  27  of the side walls  26  of the tubular member  25  is such as to form a friction grip on legs  34  of the loop  22 . The friction grip exerted on the legs  34  of the loop  22  is such as to permit the loop  22  to be drawn through the slots  28  and  29  of the cinch clip  24  for urging the cinch clip  24  along the loop  22  towards the anchor bars  20 , when a sufficient pulling force is applied to the loop  22 , for reducing the effective length of the suture thread  17  between the anchor bars  20  and the cinch clip  24 . However, the frictional force exerted by the friction grip of the crimped side walls  26  on the legs  34  of the loop  22  is sufficient for retaining the cinch clip  24  on the loop  22  at a desired position relative to the anchor bars  20  when the effective length of the suture thread  17  between the anchor bars  20  and the cinch clip  24  has been reduced to the desired effective length. This will be described in more detail below. 
     The maximum external transverse cross-sectional dimension of the cinch clip  24  is between the outer surfaces of the top wall  30  and the bottom wall  32  of the cinch clip  24 , and is substantially similar to the external transverse cross-section of the anchor bars  20  so that the cinch clips  24  of the sutures  15  are slideable within the suture bore  14  of the cannula  9 . The length of the cinch clip  24  of each suture  15  is the same as the length of each one of the anchor bars  20  of the sutures  15 . 
     In this embodiment of the invention the suture threads  17  of the respective sutures  15  are of nylon material, but may be of any other suitable biocompatible material, for example, polypropylene material or other suitable polymer material. The anchor bars  20  and the cinch clips  24  are of stainless-steel material, but may be of any other suitable biocompatible material, for example, a plastics material or a polymer material, and may, for example, be formed by injection moulding, or any other suitable plastics or polymer forming process. Additionally, the anchor bars  20  and the cinch clips  24  may be of different materials to each other. The total length of the suture thread  17  of each suture  15  from one anchor bar  20  to the other anchor bar  20  through the cinch clip  24 , in this particular case is approximately 118 mm, although it will be readily apparent to those skilled in the art that the length of the suture thread will be dependent on the lumen, vessel or organ, the portions of which are to be sutured together. 
     Returning now to the suturing instrument  1 , the diameter of the suture bore  14  of the cannula  9  is sufficient to accommodate the suture thread  17  of each suture  15  along with the anchor bars  20  and the cinch clip  24  of each suture  15  with the anchor bars  20  and the cinch clip  24  of each suture  15  aligned longitudinally with each other in the suture bore  14 , and the suture thread  17  extending along the anchor bars  20  and along the cinch clip  24  within the suture bore  14  of the cannula  9 . The anchor bars  20  and the cinch clip  24  of each suture  15  may be arranged in the suture bore  14  in any desired order. In this embodiment of the invention the cinch clip  24  of each suture  15  is arranged in longitudinal alignment with the anchor bars  20  of each suture  15  between the respective anchor bars  20 , with the opposite ends of the cinch clip  24  abutting adjacent ends of the anchor bars  20 . 
     A pusher element, in this embodiment of the invention an elongated pusher rod  35  of circular external transverse cross-section extending from a proximal end  36  to a distal end  37  is slideably located in the suture bore  14  of the cannula  9  for sequentially discharging the sutures  15  from the suture bore  14  of the cannula  9 , and for sequentially discharging the anchor bars  20  and the cinch clip  24  of each suture  15 . The distal end  37  of the pusher rod  35  extends into the suture bore  14  of the cannula  9  through a bore  33  extending through the secondary handle  8  and in turn through the proximal end  10  of the cannula  9 . The external diameter of the pusher rod  35  is less than the diameter of the suture bore  14  of the cannula  9 , so that the pusher rod  35  is slideable in the suture bore  14 . The pusher rod  35  is urgeable in the suture bore  14  in a distal direction, namely, in the direction of the arrow B, for selectively and sequentially discharging the sutures  15  from the suture bore  14  of the cannula  9  through the distal piercing tip  12  thereof, and when discharging each suture  15  from the cannula  9 , to also discharge the anchor bars  20  and the cinch clip  24  of the suture  15  selectively and sequentially through the distal piercing tip  12  of the cannula  9  in the order in which the anchor bars  20  and the cinch clip  24  of each suture  15  are located in the suture bore  14 . The distal end  37  of the pusher rod  35  is configured to engage the proximal most one of the anchor bars  20  or the cinch clip  24 , as the case may be, of the proximal most suture  15  in the suture bore  14  of the cannula  9 , so that as the pusher rod  35  is selectively and incrementally urged distally through the suture bore  14 , the anchor bars  20  and the cinch clips  24  of the respective sutures  15  are sequentially discharged from the suture bore  14  through the distal piercing tip  12  of the cannula  9 . 
     An urging means, in this embodiment of the invention comprising an actuator, which in this case comprises a linear actuator  38  illustrated in block representation in  FIG.  1   , is configured to incrementally urge the pusher rod  35  through the suture bore  14  for selectively and sequentially discharging the anchor bars  20  and the cinch clip  24  of each suture  15  from the suture bore  14  through the distal piercing tip  12  of the cannula  9  as that suture  15  is being discharged from the cannula  9 . The linear actuator  38  may comprise an electrically powered linear motor, or an electrically powered stepper motor, which would transmit drive to the pusher rod  35 , through a transmission means, for example, a rack and pinion drive, and may be located internally in or externally on the secondary handle  8 , or in any other suitable location. 
     A controller  39  is responsive to an activation signal to operate the linear actuator  38  to urge the pusher rod  35  distally in the suture bore  14  through a predefined distance. 
     In this embodiment of the invention the controller  39  comprises a signal processor provided by a programmable microcontroller  39  located in the primary handle  6 , which is programmed to activate the linear actuator  38  to urge the pusher rod  35  distally through the predefined distance in response to the activation signal. The length of the predefined distance through which the pusher rod  35  is urged in response to each one of the activation signals is equal to the length of one of the anchor bars  20 . Since the length of the anchor bars  20  and the length of the cinch clips  24  are the same, each time the pusher rod  35  is urged distally in the suture bore  14  through the predefined distance, the distal most one of the anchor bars  20  and the cinch clip  24  of the distal most suture adjacent the distal piercing tip  12  of the cannula is urged from the suture bore  14  through the distal piercing tip  12 . 
     The activation signal may be generated or derived from any suitable source, for example, by an electrical switch, a key pad or any other suitable signal generating means. In this embodiment of the invention the activation signal is produced by a human operable electrical switch, which in this case comprises a foot pedal operated electrical switch  40 . The foot pedal switch  40  is configured, so that each time it is operated it produces one of the activation signals. The microcontroller  39  is responsive to each activation signal from the foot pedal switch  40  for operating the linear actuator  38  for in turn urging the pusher rod  35  along the suture bore  14  another one of the predefined distances. 
     A power supply  41  is provided for supplying power to the microcontroller  39  and the linear actuator  38  for powering thereof, and to the foot pedal switch  40 . 
     The outer sleeve  3  of the suturing instrument  1  is of a flexible bendable material in order to accommodate bending and flexing of the outer sleeve  3  during manoeuvring of the suturing instrument  1  through bends and curves in the anatomy of a subject through which the suturing instrument  1  must be passed in order to access the lumen, vessel, organ or cavity in which the suturing is to be carried out. In this embodiment of the invention the material of the outer sleeve  3  comprises a PTFE material, and is formed by extruding the PTFE material. However, it will be understood that the outer sleeve  3  may be of any other suitable material, and in some embodiments of the invention the outer sleeve  3  may comprise a braided cable, for example, a Bowden cable. 
     Referring now to  FIGS.  4  to  7   , the cannula  9  will now be described in detail. The cannula  9  comprises a tubular member  42  of stainless-steel material of constant circular transverse cross-section and having a peripheral wall  43  of constant radial thickness along its length. The outer diameter of the tubular member  42  is approximately 1.27 mm, and the radial thickness of the wall  43  of the tubular member  42  is approximately 0.0762 mm. The tubular member  42  terminates in a distal piercing portion  44  which is substantially rigid for piercing through tissue of the lumen, vessel or organ which is to be sutured. An intermediate portion  45  extends from the distal piercing portion  44  to a proximal end portion  46  of the tubular member  42 , which terminates in and defines the proximal end  10  of the cannula  9 . 
     An interrupted helical slot  47  extends through the peripheral wall  43  of the tubular member  42  and extends along the intermediate portion  45  in order to provide the intermediate portion  45  with flexibility and bendability, so that the intermediate portion  45  is sufficiently bendable and flexible for manoeuvring the suturing instrument through bends and curves through which the suturing instrument must be passed in order to gain access to the lumen, vessel or organ in which suturing is to be carried out. In this embodiment of the invention the interrupted helical slot  47  comprises a plurality of helical slot sections  48  interrupted by a plurality of interrupted sections  49 . Each interrupted section  49  is located between an adjacent pair of the slot sections  48 . Each slot section  48  extends partly around the tubular member  42  an angular distance of approximately 240°, and each interrupted section  49  of the interrupted helical slot extends partly around the tubular member  42  an angular distance of approximately 40° between the adjacent pair of the slot sections  48 . The pitch of the interrupted helical slot  47  is approximately 1.2 mm, and the kerf width of the slot of each slot section  48  is approximately 0.025 mm. 
     The tubular member  42  is sheathed with a fine sleeve  50  of extruded polymer material heat shrunk onto the tubular member  42  over the entire length of the tubular member  42 , see  FIG.  7   . The polymer may be any suitable heat shrinkable polymer material, for example, FEP or PTFE. 
     A retaining means for releasably retaining the distal most one of the anchor bars  20  or the cinch clip  24 , as the case may be, of the distal most one of the sutures  15  in the suture bore  14  comprises an inwardly impressed dimple  51  formed on one side of the peripheral wall  43  in the distal piercing portion  44  of the cannula  9  adjacent the distal piercing tip  12  to form a corresponding inwardly extending retaining projection  52  extending inwardly into the suture bore  14 . 
     A relieving slot  53  extends longitudinally from the distal piercing tip  12  into the distal piercing portion  44  of the cannula  9  to permit outward movement of the dimpled portion of the tubular member  42  adjacent the dimple  51  in order to allow outward movement of the retaining projection  52  for releasing the distal most one of the anchor bars  20  or the cinch clip  24 , as the case may be, of the distal most one of the sutures  15 , as the pusher rod  35  is being urged distally in the suture bore  14  through the predefined distance for discharging the distal most one of the anchor bars  20  or the cinch clip  24  from the suture bore  14  through the distal piercing tip  12 . The inherent resilience of the tubular member  42  is sufficient to return the portion of the tubular member  42  with the dimple  51  to its normal undisturbed state when the distal most one of the anchor bars  20  or the cinch clip  24  has passed the retaining projection  52 , so that the next distal most one of the anchor bars  20  or the cinch clip  24  is retained by the retaining projection  52  as it returns to its undisturbed state. The retained next distal most one of the anchor bars  20  or the cinch clip  24  is retained captive by the retaining projection  52 , until the pusher rod  35  is urged distally further along the suture bore  14  through the next one of the predefined distances for urging that retained next one of the anchor bars  20  or the cinch clip  24  passed the retaining projection  52  from the suture bore  14 . 
     While the cannula  9  has been described as being of tubular steel, the cannula  9  may be of any other suitable material, and in some embodiments of the invention may be of a plastics or polymer material which would be inherently flexible and bendable, but over a short length, for example, over the length of the distal piercing portion  44  would be substantially rigid, and would be of sufficient rigidity to achieve piercing of the tissue by the distal piercing tip  12  of the cannula  9 . Needless to say, while specific linear and angular dimensions of the interrupted helical slot  47  including the slot sections  48  and the interrupted sections  49  thereof have been described, it will be readily understood that the interrupted helical slot  47  may be of any other suitable angular and linear dimensions. Needless to say, in cases where the tubular member  42  of the cannula  9  is of an inherently flexible bendable material, the intermediate portion  45  of the tubular member  42  of the cannula may be provided without an interrupted helical slot. 
     The advantage of providing an interrupted helical slot  47  in the intermediate portion  45  of the tubular member  42  which is insufficiently flexible and bendable for passing through the various bends and curves in a subject through which the suturing instrument must pass in order to gain access to the lumen, vessel or organ is that the interrupted helical slot  47  while providing the necessary degree of flexibility and bendability does not affect the linear dimensional stability of the tubular member  42 , so that the length of the intermediate portion  45  of the tubular member  42  remains constant during bending and flexing thereof, and during urging of the cannula  9  to pierce through a part of the lumen, vessel or organ during suturing thereof. 
     The pusher rod  35  is likewise of a flexible bendable material, in this embodiment of the invention a stainless-steel material. However, it is envisaged that the pusher rod may comprise an elongated wire of nitinol titanium, and such a pusher rod would have a considerable degree of flexibility and bendability. 
     To assist in further understanding of the suturing instrument  1 , the use of the suturing instrument  1  in suturing two portions of a lumen, vessel or organ together, will now be described with reference to  FIGS.  8  to  15   . In this example of the use of the suturing instrument  1 , the suturing instrument  1  will be described in the carrying out of an endoscopic sleeve gastroplasty procedure, in which a gastric sleeve  59  is formed extending through a stomach  56  of a subject. The gastric sleeve  59  is formed by suturing opposite side walls, namely, a front side wall  54  and a rear side wall  55  of the stomach  56  of the subject together. 
     An endoscope (not shown) is initially urged orally through the oesophagus and into the interior  57  of the stomach  56  of a subject. Initially spaced apart parts  58  of the front and rear side walls  54  and  55 , along which the side walls are to be sutured together to form the gastric sleeve  59  through the stomach  56 , are invaginated to form respective lines  60  of invaginated parts  58   a  and  58   b  in pairs thereof on the side walls  54  and  55 , respectively. The invaginated parts  58   a  and  58   b  of each pair thereof extend from the side walls  54  and  55 , respectively, inwardly into the interior  57  of the stomach  56 . The invaginated parts  58   a  of the pairs of the invaginated parts  58   a  and  58   b  are illustrated in  FIG.  13    spaced apart along the line  60  thereof on the front side wall  54  of the stomach  56 . The invaginated parts  58   b  of the pairs of the invaginated parts  58   a  and  58   b  are formed along the line  60  on the rear wall  55  of the stomach  56 . One of the invaginated part  58   a  and one of the invaginated part  58   b  of one pair thereof are illustrated in  FIG.  15    on the front and rear walls  54  and  55 , respectively, of the stomach  56 .  FIG.  12    illustrates three pairs of the invaginated parts  58   a  and  58   b  formed on the front and rear walls  54  and  55 , respectively, of the stomach  56 . 
     The invaginated parts  58   a  and  58   b  of each pair thereof may be formed by any suitable invaginating means, for example, by a multiband ligator which will be well known to those skilled in the art, or by a mechanical grabber. In cases where the invaginated parts  58   a  and  58   b  are formed by a multiband ligator, the multiband ligator is passed into the stomach  56  through an instrument bore of the endoscope. As each invaginated part  58   a  and  58   b  are formed, a band (not shown) is placed by the multiband ligator around the corresponding one of the invaginated parts  58   a  and  58   b  adjacent the root thereof in order to retain the invaginated part  58   a  or  58   b  invaginated. The band tightly grips the root of the corresponding invaginated part  58   a  or  58   b.    
     Once the lines  60  of the invaginated parts  58   a  and  58   b  have been formed on the respective opposite side walls  54  and  55  in the interior  57  of the stomach  56  in the pairs thereof, suturing of the stomach to form the gastric sleeve  59  therein commences. The suturing instrument  1  is entered into the stomach  56  through an instrument bore of the endoscope (not shown). During entry of the suturing instrument  1  into the stomach  56 , the cannula  9  is in the withdrawn state withdrawn into the outer sleeve  3 , so that the distal piercing tip  12  of the cannula  9  is located within the cannula bore  7  of the outer sleeve  3  in order to protect the distal piercing tip  12 , and to avoid the distal piercing tip  12  invertedly piercing tissue within the stomach  56 . 
     When the distal end  5  of the outer sleeve  3  is adjacent the first one of the invaginated parts  58   a  and  58   b  of the first pair thereof to be sutured, for example, the invaginated part  58   a  of the distal most pair of the invaginated parts  58   a  and  58   b  in the stomach  56 , the cannula  9  is urged by the secondary handle  8  from the withdrawn state to the extended state with the distal piercing tip  12  extending distally out of the distal end  5  of the outer sleeve  3 . The distal piercing tip  12  of the cannula  9  is then urged through the first one of the invaginated parts  58   a  of the first pair thereof, see  FIG.  8   . The foot pedal switch  40  is operated to produce the first one of the activation signals to the microcontroller  39 . The microcontroller  39  in turn activates the linear actuator  38  to urge the pusher rod  35  distally through one of the predefined distance, for in turn urging the first and distal most one of the anchor bars  20   a  of the distal most suture  15  in the suture bore  14  past the retaining projections  52 , and in turn, through the distal piercing tip  12 , so that the first anchor bar  20   a  is deposited on the distal side of the first one of the invaginated parts  58   a  of the first pair thereof, see again  FIG.  8   . 
     The cannula  9  is then withdrawn from the first invaginated part  58   a  of the first pair thereof with the suture thread  17  of the suture  15  extending from the first anchor bar  20   a  through the first invaginated part  58   a  of the first pair thereof, see  FIG.  9   . The foot pedal switch  40  is again operated to produce the next one of the activation signals, which in turn results in the microcontroller  39  operating the linear actuator  38  to again urge the pusher rod  35  distally through another one of the predefined distances for in turn discharging the cinch clip  24  of the distal most suture  15  from the suture bore  14  into the stomach  56 , see again  FIG.  9   . 
     The distal piercing tip  12  of the cannula  9  is urged through the second invaginated part  58   b  of the first pair thereof, and the foot pedal switch  40  is again operated to produce the next one of the activation signals. The microcontroller  39  in response to that activation signal again operates the linear actuator  38  to urge the pusher rod  35  distally through a further one of the predefined distances in the suture bore  14  to discharge the second and now the distal most one of the anchor bars  20   b  of the distal most suture  15  from the suture bore  14 , and to deposit the second anchor bar  20   b  on the distal side of the second invaginated part  58   b  of the first pair thereof, see  FIG.  10   . The cannula  9  is withdrawn from the second invaginated part  58   b  with the suture thread  17  extending from the second anchor bar  20   b  through the second invaginating part  58   b  of the first pair thereof, and with the cinch clip  24  located proximally of the first and second invaginated parts  58   a  and  58   b  on the loop  22  formed by the legs  34  of the suture thread  17  extending from the first and second anchor bars  20   a  and  20   b , see  FIG.  11   . 
     With the suture  15  so inserted in the first and second invaginated parts  58   a  and  58   b  of the first pair thereof, the now distal most suture  15  in the suture bore  14  of the cannula  9  is inserted into the next pair of the invaginated parts  58   a  and  58   b  in a similar manner to that just described, and so on for the remaining pairs of the invaginated parts  58   a  and  58   b . When sutures  15  have been inserted into all of the pairs of the invaginated parts  58   a  and  58   b , see for example,  FIGS.  12  and  13   , the suturing instrument  1  is withdrawn through the endoscope (not shown). 
     A suture tightening instrument is then urged into the stomach  56  through an instrument bore of the endoscope for tightening the sutures  15  to draw the invaginated parts  58   a  and  58   b  of each pair thereof together. Each suture  15  is tightened by holding the loop  22  of the suture thread  17 , and urging the cinch clip  24  along the legs  34  of the loop  22  towards the anchor bars  20  to reduce the effective length of the suture thread  17  between the anchor bars  20 , thereby drawing the invaginated parts  58   a  and  58   b  of the corresponding pair thereof together. Any suitable type of suture tightening instrument may be used. 
     Typically, such a suture tightening instrument would comprise an outer sleeve terminating in a distal abutment end. An operating rod terminating in a distal hook or a distal grabber would be slideable in the outer sleeve for engaging the loop  22  of each suture  15 , and for drawing the loop  22  into the outer sleeve until the cinch clip  24  abutted the distal abutment end of the outer sleeve. The loop  22  of the suture  15  would then be drawn further into the outer sleeve of the tightening instrument, for in turn urging the cinch clip  24  along the loop  22  towards the anchor bars  20 . 
     With the hook or grabber extending outwardly from the distal end of the sleeve, the hook or grabber is engaged with the loop  22  of the first of the sutures  15  to be tightened. The hook or grabber is then withdrawn into the sleeve thereby pulling the loop  22  therein until the cinch clip  24  engages the distal abutment end of the sleeve. Once the cinch clip  24  engages the distal abutment face of the sleeve, further pulling of the loop  22  into the bore of the outer sleeve results in the cinch clip  24  being urged along the loop  22  towards the anchor bars  20 , thereby progressively reducing the effective length of the suture thread  17  between the anchor bars  20  and the cinch clip  24 , for in turn drawing the invaginated parts  58   a  and  58   b  of the pair thereof together. Drawing the first and second invaginated parts  58   a  and  58   b  together results in the front and rear walls  54  and  55  of the stomach  56  adjacent the corresponding pair of the invaginated parts  58   a  and  58   b  being drawn together. As discussed above, the frictional grip of the crimped parts  27  of the side walls  26  of the cinch clips  24  acting on the legs  34  of the loops  22  of the suture thread  17  of the respective sutures  15  is sufficient to retain the cinch clips  24  at the desired position on the loops  22  of the sutures  15 , thereby retaining the invaginated parts  58   a  and  58   b  of the pair thereof together. 
     On completion of tightening of the suture  15  of the first pair of the invaginated parts  58   a  and  58   b , the suture  15  on the next adjacent pair of the invaginated parts  58   a  and  58   b  is then tightened, and so on until all the sutures  15  have been tightened, thereby drawing the pairs of the invaginated parts  58  together, and in turn drawing the front and rear walls  54  and  55  of the stomach  56  together along the line  60  of the invaginated parts  58  to form the gastric sleeve  59  extending through the stomach  56 , see  FIG.  15   . On completion of tightening of the sutures  15 , the suture tightening instrument is then withdrawn through the endoscope. 
     Referring now to  FIGS.  16  and  17   , there is illustrated a portion of a suturing instrument according to another embodiment of the invention indicated generally by the reference numeral  65 . The suturing instrument  65  is substantially similar to the suturing instrument  1  described with reference to  FIGS.  1  to  7   , and similar components are identified by the same reference numerals. Although in  FIGS.  16  and  17    the suturing instrument  65  is illustrated without an outer sleeve, similar to the outer sleeve  3  of the suturing instrument  1 . The suturing instrument  65  will be provided with an outer sleeve similar to the outer sleeve  3  of the suturing instrument  1 . 
     The only difference between the suturing instrument  65  and the suturing instrument  1  relates to the manner in which the sutures  15  are located in the suture bore  14  of the cannula  9  of the suturing instrument  65 . In this embodiment of the invention each suture  15  is located in the suture bore  14  with the anchor bars  20  located end-to-end and abutting each other, and the cinch clip  24  is located distally of the two anchor bars  20 . Otherwise, the suturing instrument  65  is similar to that of the suturing instrument  1 . 
     In use, before each pair of invaginated parts  58  of the lumen, vessel or organ are pierced by the distal piercing tip  12  of the cannula  9  of the suturing instrument  65 , the foot pedal switch  40  must be operated to produce the activation signal to the microcontroller  39  in order to operate the linear actuator  38  to urge the pusher rod  35  through one of the predefined distances for discharging the cinch clip  24  of the distal most one of the sutures  15  from the suture bore  14  through the distal piercing tip  12  into the interior of the lumen, vessel or organ. Once the cinch clip  24  has been discharged from the suture bore  14  of the cannula  9 , the distal piercing tip  12  of the cannula  9  is urged through the first invaginated part  58   a  of the first pair thereof. The foot pedal switch  40  is operated for in turn operating the linear actuator  38  to urge the pusher rod  35  through another one of the predefined distances for discharging the distal most one of the anchor bars  20  from the suture bore  14  to the distal side of the pierced invaginated part  58   a  of the pair thereof. Thereafter, operation of the suturing instrument  65  is similar to the operation of the suturing instrument  1 . 
     Referring now to  FIGS.  18  and  19   , there is illustrated a portion of a suturing instrument according to another embodiment of the invention indicated generally by the reference numeral  70 . The suturing instrument  70  is substantially similar to the suturing instrument  1 , and similar components are identified by the same reference numerals. The main difference between the suturing instrument  70  and the suturing instrument  1  is that in this embodiment of the invention the cannula  9  is not provided with the interrupted helical slot. However, in this embodiment of the invention the tubular member  42  of the cannula  9  is provided with a longitudinally extending slot  71  extending through the peripheral wall  43  of the tubular member  42  from the distal end  11 , terminating just short of the proximal end  10  of the cannula  9 . The longitudinally extending slot  71  communicates with the suture bore  14  for accommodating the suture threads  17  of the respective sutures  15  therethrough. The majority of the suture threads  17  of the sutures may be located in the slot  71  or may extend through the slot  71 , and thus into the cannula bore  7  of the outer sleeve  3 . The provision of the slot  71  to accommodate the suture threads  17  therein or therethrough allows the cannula  9  to be provided with a slightly smaller diameter suture bore  14 . By reducing the diameter of the suture bore  14  of the cannula  9 , the cannula  9  may be provided to be of smaller outer diameter than would otherwise be the case. The diameter of the cannula  9  dictates the diameter of the invaginated parts  58  which must be formed, and therefore by reducing the diameter of the cannula  9 , the diameter of the invaginated parts  58  may also be reduced. 
     A further advantage of the provision of the slot  71 , is that it allows the suture threads  17  of the sutures  15  to be located in the cannula bore  7  of the outer sleeve  3 , and since the inner and outer diameters of the outer sleeve  3  is less critical than the outer diameter of the cannula  9 , the suture threads  17  of the sutures can be stored in the cannula bore  7  of the outer sleeve  3  without having any detrimental effect on the suturing instrument  70 . 
     Otherwise, the suturing instrument  70  and its use are similar to the suturing instrument  1 . 
     The anchor bars  20  and the cinch clips  24  may be arranged in the suture bore  14  of the cannula  9  of the suturing instrument  70  in either of the arrangements described with reference to the cannula  9  of the suturing instrument  1  or in the cannula  9  of the suturing instrument  65 . It will of course be appreciated that in some embodiments of the suturing instruments  1 ,  65  and  70 , the anchor bars  20  and the cinch clip  24  of each suture  15  may be arranged with the cinch clip  24  proximal of the two corresponding anchor bars  20 . 
     While the urging means for urging the pusher rod  35  through the predefined distances has been described as comprising a linear actuator, any other suitable actuators may be provided, and such actuators may comprise either linear or rotary motor. When provided as a rotary motor, a transmission system between the rotary motor and the pusher rod would be provided for converting rotational motion of the rotary motor into linear motion of the pusher rod. Such a transmission system may, for example, comprise a rack and pinion drive or a worm and gear drive or both. It will also be appreciated that instead of the actuator being electrically powered, the actuator may be pneumatically powered. Further, it will be appreciated that the linear motor or indeed a rotary motor of the linear actuator may act on the pusher rod through a ratchet system, whereby, the ratchet would sequentially engage spaced apart projections or recesses on the pusher rod for urging the pusher rod through the predefined distances. 
     It will also be appreciated that any number of sutures may be located in the suture bore of the cannula  9 , and the number of sutures which may be located in the suture bore of the cannula would be limited only by the length of the cannula. 
     While the suturing instruments have been described as comprising sutures of a specific type, it will be readily apparent to those skilled in the art that any other suitable sutures may be used in conjunction with the suturing instruments. It will be appreciated that the sutures may comprise different types of anchor bars and cinch clips to those described. Further, it will be appreciated that while it is desirable, it is not essential that the anchor bars of each suture be of the same length, and furthermore, it will be appreciated that the cinch clips of each suture need not be the same length as the anchor bars thereof. 
     In cases where the anchor bars of each suture are of different lengths, and the cinch clip of each suture is of a different length to the anchor bars, the microcontroller would be programmed to operate the linear actuator to urge the pusher rod  35  through the appropriate first, second or third predefined distance depending on the lengths of the anchor bars and/or cinch clips for discharging the relevant ones of the anchor bars and/or the cinch clip, as the case may be, and the first, second and third predefined distance through which the pusher rod  35  would be urged by the actuator would correspond to the length of the respective ones of the anchor bars and the cinch clip to be discharged from the suture bore through the distal piercing tip  12  of the cannula. 
     Needless to say, it is not essential that the anchor bars be of circular transverse cross-section, all that is required is that they be of cross-sectional dimensions suitable for sliding in the suture bore of the cannula. Needless to say, other types of cinch clips may be used in conjunction with the sutures other than a cinch clip of the type illustrated in  FIG.  3   . 
     While the cannula and the outer sleeve of the suturing instruments according to the invention have been described as being of circular transverse cross-section, it will be readily apparent to those skilled in the art that the outer sleeve and the cannula of the suturing instruments may be of any suitable transverse cross-section, for example, the cannula and the outer sleeve may be of square, rectangular, triangular, hexagonal, octagonal, or any other suitable transverse cross-section. Further, it is envisaged that the transverse cross-section of the cannula may be different to that of the outer sleeve. Additionally, in some embodiments of the invention it is envisaged that the cannula may be keyed in the outer sleeve in order to prevent rotation of the cannula in the outer sleeve relative to the outer sleeve. 
     Additionally, it is envisaged that in some embodiments of the invention the suturing instrument may be provided without an outer sleeve. 
     It is also envisaged that in some embodiments of the invention a sensing means may be provided adjacent the distal end of the cannula which would be capable of identifying and distinguishing between the cinch clip and the anchor elements of each suture, and may also be configured to distinguish between the two anchor elements of each suture. Such a sensing means would produce a signal indicative of the one of the cinch clip and the anchor elements adjacent the distal piercing tip of the cannula and next to be discharged therethrough. The signals from the sensing means would be read by the microcontroller, which would then control the linear actuator to urge the pusher rod distally the appropriate predefined distance for discharging the relevant one of the suture or anchor element adjacent the distal piercing tip of the cannula. 
     It is also envisaged that the microcontroller  39  may be pre-programmed to operate the linear actuator through three predefined distances, for example, a first predefined distance to discharge one of the anchor bars of each suture from the suture bore of the cannula, a second predefined distance to discharge the other one of the anchor bars of each suture from the suture bore of the cannula, and a third predefined distance to discharge the cinch clip of each suture from the suture bore of the cannula. It is envisaged that the sequence of the first, second and third predefined distances through which the linear actuator  38  would be operated would be selectable, and would be selectable to match the sequence in which the anchor bars and the cinch clips of the respective sutures are located in the suture bore of the cannula. It is also envisaged that the lengths of the first, second and third predefined distances would be such as to match the lengths of the respective anchor elements and the cinch clip, and would be selectable. 
     While the suturing instrument has been described for use in an endoscopic sleeve gastroplasty procedure, it will be readily apparent to those skilled in the art that the suturing instruments according to the invention may be used for suturing any two portions of a lumen, vessel or organ together either internally in or externally of the lumen, vessel or organ. 
     It will also be appreciated that while the suturing instruments have been described for suturing the portions of the lumen, vessel or organ together by forming invaginated parts of the lumen, vessel or organ adjacent the areas which are to be sutured together, while this is an advantageous way of suturing portions of a lumen, vessel or organ together, other suitable methods may be used. For example, in some embodiments of the invention it is envisaged that the suturing instrument may be operated within the lumen, vessel or organ, and the distal piercing tip  12  of the cannula  9  would be urged through one of the portions of the wall of the lumen, vessel or organ to be sutured from the interior thereof, and one of the anchor bars of the suture would be deposited on the exterior side of the wall of that portion of the lumen, vessel or organ. The distal piercing tip of the cannula would then be operated to pierce through the other portion of the wall of the lumen, vessel or organ to be sutured and would deposit the other one of the anchor bars of the suture on the exterior side of the wall of that portion of the wall of the lumen, vessel or organ. Further sutures would be inserted sequentially along the portions of the lumen, vessel or organ at spaced apart intervals along the portions thereof in a similar manner. The sutures would then be tightened, thereby pulling the two portions of the wall or walls of the lumen, vessel or organ together. Needless to say, such a suturing operation could be carried out externally of the lumen, vessel or organ whereby the suturing instrument would be operated to pierce through the wall of the lumen, vessel or organ from the exterior to the interior thereof. 
     It is also envisaged that as well as the suturing instrument being entered into the lumen, vessel or organ to be sutured through the instrument bore of an endoscope, the suturing instrument may be entered into a lumen, vessel or organ or indeed a cavity in which suturing is to be carried out through the instrument bore of any other suitable access device, for example, a laparoscope, colonoscope, or any other suitable access devices. 
     While the parts to be invaginated have been described as being invaginated by a multiband ligator, any other suitable invaginating means for forming invaginated parts may be used, for example, a grabber or a grasper, which would grab or grasp a part of the portion of the lumen, vessel or organ to be sutured and would pull the part inwardly, or outwardly as the case may be from the wall of the subject, and while the part is grabbed or grasped, the cannula would be operated to pierce through the grabbed or grasped part, and the distal most one of the anchor bars of the distal most suture in the suture bore would be dispensed on the distal side of the grabbed or grasped part. Once the cannula has been withdrawn from the grabbed or grasped part, the grabber or grasper would release the invaginated part.