Endoscopic multiple ligating clip applier

Abstract: An endoscopic clip applying system as described which contains a venting system and a clip applying support system which prevents closure of the mechanism before firing. Also, the system ensures proper loading of the clips and prevents them from falling out during loading. Further, the system describes an easily manufacturable, positively opening system which has minimized size requirements. Furthermore, a lock-out mechanism is provided so that the mechanism may not be inadvertently fired. The shaft resists excessive torque as well as holds the clip in place during firing. There are provisions for sealant and non-back up of the clips, as well as features which make the clip properly placed for closure.

Description: Generally, this invention relates to ligating clip appliers. More specifically, this invention relates to endoscopic ligating clip appliers. Most specifically, this invention relates to endoscopic ligating clip appliers, where the applier is capable of placing down a sequential number of clips from a multiple clip applying cartridge. There have been many advances in recent years in the field of endoscopy. Many of these advances have come due to the increased versatility of endoscopic staple and clip applying mechanisms. These mechanisms are placed through the cannula of an endoscopic trocar so that tissue may be cut, stapled or ligated. With use of these endoscopic stapling and ligating mechanisms, there have become available means for the proliferation of endoscopic ligating procedures. EP-A-0409569 discloses a multiple ligating clip applier comprising an endoscopic clip applying mechanism including a pair of jaws, a feeder mechanism including a feed bar for feeding ligating clips to the clip applying mechanism, and a firing mechanism held remotely from the clip applying mechanism by a support tube. The feed bar and the firing mechanism can be prevented from actuating by provision of a locking means comprising a resilient catch. When the applier is to be used, however, the locking means can be released. Document GB-A-2 128 477 discloses a non-endoscopic ligating clip applier comprising a pair of jaws for applying ligating clips, a clip firing mechanism held remotely from the clip applying mechanism, and a clip feeder mechanism which prevents inadvertent closure of the jaws when pressure is applied on the jaws, the feeder mechanism including a feed bar for feeding ligating clips to the clip applying mechanism, the feed bar having outer edges which contact inner edges of the jaws when the feed bar is advanced towards the clip applying mechanism. It is an object of the invention to provide a multiple ligating clip applier which provides for clip closure without the threat of dropping the clip from the instrument into the wound site or accidental closure of the jaws during insertion of the applier through a cannula of a trocar. The present invention provides an endoscopic multiple ligating clip applier according to claim 1. The device is created so that the clips are applied in one orientation, but it is understood that the clip applier can be rotated to advantageously orient the system. The preferred clip applying mechanism of the invention also has a venting system which comprises a channel through which the device may be vented. This helps insure adequate firing within the system. There is also described a feed bar support mechanism which contains a pair of protrusions which prevent the deflection of the clip applier jaws during its insertion into the cannula. Furthermore, there is described a cam channel mechanism which provides a uniform closing force upon the ligating clip held within the jaws. A tab within the cam channel prevents the jaws from closing, so that these jaws may reliably receive a new clip after the instrument has been fired to place a clip around tissue. Other novel features are provided in this system. First, there is a mechanism comprising a lever which falls into the firing path of the device so that the instrument cannot be fired after the last clip has been fired from the mechanism. Second, a finger located on the clip applying mechanism is described, which secured holds the clip about to be fired in place on the jaws of the instrument. Third a torque-resisting shaft is placed on the instrument, to prevent transverse deflection of the tip of the instrument during firing. Another set of unique features of the instrument are such things as a pair of jaws provide for multiple contact during firing, to minimize deflection in the arms of the jaws, enabling proper closure of the clip. This minimization of deflection provides for more consistent and improved clip closure. A clip feeding escapement system provides that only one clip is actually applied to the open jaws after the clip has been fired. Furthermore, there is a sealing system provided for in the mechanism which adequately provides the sealing of pneumoperitoneum. Also, there is located on the shroud of the instrument a v-shaped notch, which helps maintain the tissue on the jaws of the instrument. This notch helps secure proper position of the tissue for firing of the instrument and clip closure. This device has been described in connection with a number of various features contained in its embodiment. These features will be better understood when taken in connection with the attached detailed description of the drawings and described in connection with the following detailed description of the invention. Figure 1 is a perspective view of the left hand side of the endoscopic multiple clip applying instrument of this invention; Figure 2 is a side plan view of the instrument of the invention in the open position; Figure 3 is a side plan view of the instrument of the invention in the closed position; Figure 4 is a perspective view of the instrument of the invention inserted through a trocar; Figure 5 is an assembly view of the handle of the invention; Figure 6 is a partial cut-away view of the handle of the invention in its relaxed position; Figure 7 is a partial cut-away view of the handle of the invention in its firing postion; Figure 8 is an assembly view of the tubular endoscopic portion of the instrument of the invention; Figures 9, 10 and 11 are sequential plan views of the clip as placed in the jaws of the invention when in the open, closing and closed positions respectively; Figure 12 is a longitudinal cross-sectional view of the invention taken across lines 12-12 as seen in Figure 2; Figure 13 is a cross-sectional view of the invention taken along lines 13-13 as seen in Figure 1; Figure 14 is a cross-sectional view as taken across lines 14-14 of Figure 1; Figure 15 is a cross-sectional view of the invention describing the cam channel mechanism taken across lines 15-15 of Figure 2; Figure 15A is a cross-section view taken across lines 15A-15A of Figure 15; Figure 16 is a cross-sectional view of the invention describing the handle-latch combination; Figure 16A is a cross-sectional view of the invention taken across lines 16-16 of Figure 3 emphasizing the lockout mechanism used in the endoscopic clip applier; Figure 16B is a cross-sectional view of the invention taken across lines 16-16 of Figure 3, emphasizing the rearward retention mechanism for the clip applier in the open-state with an unformed clip of the invention; Figure 16C is an identical view as Figure 16B, except that it demonstrates the jaws in a closed state, with a formed clip; Figure 17 is a plan view of the jaw component of the invention; Figure 18 is a view of the jaw as seen in Figure 17 when in the closed postion; Figure 18A is a cross-sectional view across lines 18A-18A of Figure 18; Figure 18B is a cross-sectional view across lines 18B-18B of Figure 18; Figure 19A is a cross-sectional view of the clip feeding escapement system of this invention across lines 19A-19A of Figure 1; Figure 19B is the view of Figure 19A in the closed position; Figure 20 is a partial cross-sectional view of the shaft assembly across lines 20-20 as seen in Figure 1; and Figure 21 is a cross-sectional view of Figure 20 as seen across lines 21-21 of Figure 20; Figures 22A, 22B and 22C are sequential views of the clip feed timing mechanism of the invention. An endoscopic multiple ligating clip application mechanism 1 is shown in Figures 1-22. As better seen in Figures 1, 2, 3 and 4, this multiple ligating clip mechanism 1 is useful for applying clips through a surgical trocar. As seen in Figure 4, the ligating clip mechanism 1 is applied through the cannula of a trocar, so that a vessel can be occluded or tissue can be clamped. The mechanism applies a series of clips 8 by means of jaws 11 which are fired remotely by a trigger 25. As seen in Figures 2 and 3, the trigger 25 is compressed, causing the jaws 11 to close, and squeezing a ligating clip 8 therein. After closing the clip 8, the jaws 11 are released and there is loaded another clip 8 in its place. As better seen in Figures 5, 6 and 7, there is described handle halves 16, 28 which enclose the trigger 25 mechanism for firing the device. The handle halves 16, 28, surround the firing mechanism and afford a pivot point 110 around which trigger 25 rotates. Trigger 25 is associated with a former plate 22 and a feeder link 23. As seen on the right hand side of Figure 5, feeder link 23 is attached to the trigger 25 and holds in place the feeder plate 24. Feeder plate 24 is connected to return spring 27, at post 24a which is in turn connected to a post 22a on former plate 22. Thus, when the trigger is fired, the former plate 22 is pushed forward. Pivot 113 on trigger 25 slides in channel 115 in handle half 16 and causes slot 111 to be urged toward the rear of the instrument. Slot 118 on feeder link 23, in turn, causes feeder plate 24 to be urged to the rear of the instrument. Simultaneously trigger 25 rotates so that slots 114 causes dowel pin 26 to slide in slot 112 of plate 24. Also, dowel pin 26 urges point 116 in former plate 22 forward, as it slides within slot 117 in handle half 16. When the trigger 25 is released, the tension on return spring 27 causes the trigger 25 to return to its position, by acting upon feeder plate 24 through post 24a and former plate 22 through post 22a so that trigger 25, dowel pin 26, and the former plate 22 are moved back to their non-stressed position. Dowel pin 26 holds feeder plate 24 in place on right handle 16. An anti back-up lever 19, lost motion lever 18, latch 17, and torsion spring 20 and pre-cock trigger 21 will all be further described as part of this invention. When the trigger 25 is activated, the former plate 22 is caused to move forward so that cam channel 12 connected to former plate 22 within support tube 15 is moved forward. This actuates the endoscopic clip applying mechanism. As seen in Figure 8, the feed bar 9 and cam channel 12 surround floor 10. These mechanisms are sealed between lower shroud 13 and seal cap 14 within the support tube 15. Attached to cam channel 12 is jaw 11. This jaw will close about a ligating clip 8 to seal tissue or vessels. Held in clip track 4 is feeder spring 5, lock lever 6, feed shoe 7, and a series of clips 8. The clip track 4 is capable of advancing forward a series of clips and loading them within the arms of jaw 11. A lifter spring 3 is held in place over clip track 4 by top shroud 2, and will place the first clip 8a of a stack of clips 8 into the plane of feed bar 9 to be positioned into jaws 11. Also, the seal cap 14 and lower shroud 13 hold cam channel 12, floor 10 and feed bar 9 in place within the support tube 15. In operation, the trigger 25 is fired and former plate 22 causes cam channel 12 to move forward. Cam channel 12 encloses jaws 11 to seal a clip 8 around tissue. After trigger 25 is released, cam channel 12 retracts so that jaws 11 open. The magazine of clips 8 is advanced forward so that another clip 8 is held within jaw 11. This occurs when spring 27 is released, causing feeder plate 24 to advance. This in turn causes feed bar 9 to advance the first clip 8a from the stack of clips 8 whch has been positioned in the path of the feed bar 9 by spring 3 into jaws 11. This operation can best be seen by observing Figures 9, 10 and 11 in conjunction with Figures 6 and 7. Of course, each of the mechanisms as disclosed by this invention will be further described herein. Specifically, it is to be noted that the orientation of clips 8 is transverse to that of the orientation of the handle portion of the instrument 1. In this way, the user is able to grip the trigger 25 on the handles 16, 28 of the instrument 1 so that the user's hand is held parallel to the plane on which the clips are fired. This affords a more typical reference point for the user, so that it is more comfortable for operation of the instrument. Now, each of the various features of the clip applying mechanism will be described. The first feature is a venting system for endoscopically applying these clips. As seen in Figure 12, there is located a vent 120 on the outside of the instrument. This vent 120 is attached to an open channel 122 within the lower shroud 13 within the support tube 15. Open channel 122 is connected to a hole 124 in the lower shroud 13. This allows fluid passage between tube 15 and lower shroud 13. This hole in lower shroud 13 affords fluid passage between the upper portion 126 of the instrument and the inner channel within lower shroud 13. This open channel 122 within support tube 15 runs along the longitudinal axis of the support tube 15 and provides a path of least resistance for fluid flow. The hole 124 in the lower shroud 13 at the end of this channel 122 provides a venting path to the upper portion 126 of the shaft assembly. Fluid is therefore vented from the instrument 1. The instrument is much more capable of functioning under between 13,3 and 20,0 mbar (10 and 15 mm mercury pressure). Pressure is equalized across the entire insturment, and a path of least resistance is provided. In this way, the likelihood of functional failures of the instrument when used interoperatively is reduced. Furthermore, as seen in Figures 13 and 14, there is also disclosed a support mechanism for the endoscopic multiple clip applier. This support mechanism provides longitudinal support for the ligating clip 8 during application onto tissue, and transverse support of the jaws 11 during insertion through the cannula 105 of the trocar during endoscopic surgery. As seen in Figures 13 and 14, when the instrument jaws 11 are opened the ligating clip 8 is positioned between the jaws 11a, 11b of the instrument. The feed bar 9 is advanced completely forward. When the instrument is inserted through a cannula of a trocar and applied to tissue it is important that the jaws are prevented from closing. As seen in Figure 14, there are outboard protrusions 132 on the feed bar 9. These outward protrusions 132 contact the angled arms 134 of the clip 8 in the jaws. Also, the feed bar 9 has a tapered outer edges 130 which contacts the inner edges 136 of the jaw 11. Thus, jaws 11a, 11b are prevented from being squeezed transversely during insertion through a cannula 105. The outboard protrusions 132 prevent the clip 8 from moving longitudinally during insertion, and the outer edges 130 of the feed bar 9 prevent the inadvertent jaw closure during insertion. This aspect advantageously promotes improved clip closure and prevents dropping of a clip from the instrument into the wound site during usage. Another feature is the clip closure cam channel 12 used in this instrument. Cam channel 12 helps close the jaws 11 of the ligating clip instrument. The cam channel mechanism 12 travels longitudinally along the axis of the tubular support tube 15 of the instrument. The cam channel 12 lies in the longitudinal axis of the jaws 11. The distal end 140 of the cam mechanism is rectangular and cross sectioned, as can be seen in Figure 15. As in Figure 15A, on the anterior surface of the cam channel 12 there is a dovetail joint 142, 142a, which holds the cam channel 12 together mechanically. This dovetail mechanical lock reduces the transverse (side-to-side) deflection of the cam channel 12 during clip formation. In this way, while the longitudinal motion of the cam channel 12 takes place, transverse motion of the cam channel 12 is prevented. Therefore, the dovetail mechanical lock 142, 142A incorporated into the cam channel 12 improves the dimensional stability cam channel 12 and improves the reliability of closure of the ligating clip 8. As also seen in Figure 15, there is described a pair of tabs 144 in the cam channel 12. These tabs 144 are bent at the distal end of the cam channel 12 and are oriented perpendicularly through the longitudinal axis of the jaw 11 of the instrument 1. When jaws 11a, 11b are open, the outer edges of the tabs 144 rest on the arms of 11a, 11b of the jaws 11, preventing them from being moved inwardly toward each other, as during closure of the mechanism. When there is a ligating clip 8 closed within the jaws 11, the cam channel 12 retracts from the forming site and the edges of the tabs 144 again contact the edges of the jaws 11, forcing the jaws 11 outward. This guarantees that the jaws are open to receive a clip. Clip feeding reliability of the instrument is increased, while not compromising the process of clip closure. As seen in Figure 16A, there is also described in this instrument a pivoting lock-out lever 6, which is attached to the feeder shoe 7. The lever 6 pivots upon contact with top shroud 2 into the path of the feed bar 9, as seen in Figure 16A. This lever 6 when downwardly pivoted, as seen in Figure 16a, prohibits the complete forward motion of the feed bar 9. This then causes the biased latch 17 to engage wall 150 of the former plate 22, seen in Figure 16. Therefore, this multiple redundant system allows for locking of the instrument after the last clip 8 is fired at the forward end of the instrument by the jaws 11, as well as at the rearward end of the instrument. The lock-out lever 6 pivots into place only when there are no remaining clips 8 in clip track 4. Had there been a remaining clip 8, the feeder spring 5 would not have been able to bias feed shoe 7 to clear the path for the lock-out lever 6, such that lever 6 is caused to pivot into the path of the feed bar 9. When this locking out by lever 6 occurs, the feed bar is prevented from completely moving forward and therefore the biased latch 17 engages the wall 150 of the former plate 22. Also, as seen in Figure 16B, there is described a mechanism that minimizes the rearward movement of a clip 8 in the applier during application onto the vessel. It is also capable of maintaining the clip 8 in its proper forming area throughout complete closure of the mechanism. This mechanism comprises of the floor 10 held within support tube 15. The floor 10 protrudes into the longitudinal plane of the clip forming area 160 of the jaws 11A, 11B of the instrument. A clip retaining finger 156 on the floor 10 is provided with a perpendicularly bent tab 154 at its distal end, as seen in Figure 16B. This retaining finger is unitary to the floor 10 and is also biased so that it is parallel with the longitudinal plane of the jaw clip forming area 160. Distal tab 154 of the finger 156 is positioned perpendicularly to the forming area such that the tab minimizes the rearward movement of the clip 8 within the jaws 11A, 11B. As the jaws close, the floor 10 is ramped out of the plane of the clip forming area. Yet, throughout closure of the clip and ramping of the floor 10, the bent tab 156 of the clip retaining finger remains in the plane of the clip 8 and clip forming area 160 of the jaws 11A, 11B and is positioned behind the apex of the clip 8. This is better seen in Figure 16C. Therefore, the movement of the clip 8 as held within the jaws 11 is always controlled and the finger 156 and tab 154 of the floor 10 constantly remain in the plane of the forming of a clip 8. As may be seen in Figure 8, support tube 15 is torque resistant. That is, the support tube 15 is cylindrical and hollow and is made of a non-resilient material. The tube ends near the distal end of the shaft, and close to the clip forming jaws 11. It is connected to the top shroud 2 so that the positioning of these elements together provide the necessary resistive support of the mechanism for the forming of clip 8. Because the material from which the support tube 15 is made is nonresilient, the stability of the instrument is increased and this helps increase the placement accuracy of a clip 8. As seen in Figures 17, 18, 18A and 18B, the jaws 11A, 11B of the instrument are described so that they contact at their distal end 178 and at primary heel 176 located proximally to the closing ramps 172 of each jaw. This is better seen in Figures 18 and 18A. As seen in Figure 17, the jaws 11a, 11b are generally maintained in an open position. The contact of the primary heels 176 minimizes the deflection in the arms 172 of the jaws 11a, 11b to properly close a clip 8. This initial contact minimizes arm deflection and torque and supports the system during loading. When the jaw is fully closed, as seen in Figures 18 and 18B, the last portion of clip closure causes the magnitude of loading conditions to increase. Two opposing posts 174, called anti-torque posts, contact with each other near the forming areas of the jaws and counteract the torque placed on the jaws. This provides for a more consistent and improved clip closure. Also, the tips 178 of each jaw contact. Thus, with the anti-torque mechanism described herein, the jaws may be smaller in size as they do not need to be as torque resistant. The jaws 11a, 11b also provide improved clip closure mechanism because deflection is minimized. This provides for reliability of the instrument along with minimization of size. As seen in Figures 19A and 19B, there is described a feeding and escapement system which improves the clip feeding reliability of the endoscopic multiple clip applier 1. This is done by minimizing the possibility of double feeding of clips into the jaws. The system consists of two independent parts. A valve 182 unitary to the clip track 4 holds the stack of clips 8 stationary while the forward most clip is biased by lifter spring 3 into the plane of feed bar 9. As the instrument is actuated, the feed bar 9 is caused to retract toward the rear of the instrument, and from the lifter spring 3. When the feed bar 9 retracts, the ramp 180 on feed bar 9 is engaged with primary valve 182 located in the clip track 4, thus, clip track 4 is closed. When clip track 4 is closed, the stack of clips 8 is held stationary. As the feed bar 9 retracts further from lifter spring 3, valve 182 is closed by ramp 180, and lifter spring 3 is actuated, causing the forward most clip 8 to be biased into the plane of the feed bar 9 so that it may be the next clip 8 loaded within the jaw. This is better seen in Figure 19B. Only one clip 8, however, can be biased toward the feed bar, because the primary valve 182 located in clip track 4 previously uses check port 184 to hold back any additional clips 8 in the clip stack. The possibility of double feeding of clips is reduced, improving the reliability of the applier. As seen in Figures 20 and 21, there is disclosed a sealing mechanism located near the proximal end of the shaft assembly of the endoscopic multiple clip applier. The sealing mechanism is circular in cross section and fits tightly through four crushed ribs 196 within the fits tightly through four crushed ribs 196 within the shaft support tube 15. Within the sealing mechanism are three chambers 190, 192 as identified in Figure 20, through which the feeding and forming mechanisms of the instrument pass. The primary chamber 190 is an area through which a sealant fluid may be injected. Sealent may be inserted through insertrion holes 194, 198. The outer or secondary chambers 192 are provided as spill-over areas for the sealant. This is better seen in Figure 20. The ends of the sealing mechanism are closed to prohibit the migration of sealant from the chambers 190 to the functional areas of the instrument. The sealing system provides a cushioning mechanism to minimize instrument recoil during firing and retraction of trigger 25. This closed sealing mechanism also prevents the intraoperative gross loss of pressure through the instrument itself, while minimizing, through ribs 196, the possibility of instrument functional failure due to sealant migration. The system is sealed from outside the patient, and it is itself sealed from the moving parts of the instruments. As seen in Figures 22A, 22B and 22C, the triggering system taken in conjunction with Figure 5 consists of a precock trigger 21, which is pre-stressed and pivots on a post 206 into handle portion 16. Precock trigger 21 is biased so that there is eliminated any clearance between the precock trigger 21 and the former plate 22 located within the handles 16, 28. As the feeder plate 24 is retracted to the rear of the instrument away from the forming site (Figure 22B), during handle actuation, a camming surface 196 on the feeder plate 24 contacts a cylindrical post 198 on the precock trigger 21. This causes the rotation of the precock trigger 21 into its precocked position as seen in Figure 22B. In its precocked position a projection 200 of the precock trigger 21 becomes locked behind a wall 202 extending from the former plate 22. The precock trigger 21 now blocks the path of a tab 204 extending from feeder plate 24. The feeder plate 24 cannot feed the next clip 8 into the jaws from this point until the timing wall 202 extending from the former plate 22 allows the precock trigger 21 to rotate out of the path of the feeder plate 24. This method of timing causes a sequencing operation for feeding clips which eliminates the possibility of feeding a second clip into the jaws 11 of the instrument in the event that the instrument is partially fired and re-opened. As can be further seen in Figures 5 and 22C, torsion spring 20 connects to both lost motion lever mechanism 18 and anti back-up lever 19. The objective of the anti back-up lever 19 is to assure that a pressure is constantly maintained on the jaws 11 by cam channel 12 as the clip is being closed. Anti back-up lever 19 therefore causes cam channel 12 to be constantly urged forward. This prevents the clip 8 from falling out from the jaws 11a, 11b until the applier is fully actuated. The system is actuated by rotation of the precock trigger 21, so that the tab 208 extending from the base of the precock trigger 21 into hole 210 of the lost motion lever 18 (and thus connected to the anti back-up lever 19 via torsion spring 20) acts as a toggle mechanism to engage and disengage the anti back-up lever 19. The hole width 210 of the lost motion lever 18 determines the relative motion of the precock trigger 21 and the lost motion lever 18. This allows timing of the anti back-up actuation mechanism a9 to be adjusted in relation to the actuation of the precock trigger 21. The anti back-up lever 19 is constructed of a resilient material and has teeth 214 which engage the metallic teeth 212 on former plate 22, as seen in Figure 5. The anti back-up lever 19 has a cam surface which tends to cam the teeth 214 away from former plate 22, in the event that the anti back-up mechanism must be overridden. Finally, as seen Figures 9, 10 and 11, there is a tissue stop located as a V notch 220 in top shroud 2. This tissue stop is located on the rear end of the clip forming area within the jaws 11. As seen in Figure 9, this maintains the clip 8 within the forming areas of the jaws 11 and guarantees proper gap size of the clips. It also prevents the possibility of tissue damage by closing the clips too loosely or too tightly. This idea promotes more secure clip closure and minimizes the possibility of damage to tissue. Thus, as can be seen, in operation the mechanisms of this invention all function similarly, so that the system is able to operate a closure of a ligating clip about a blood vessel. The handle operates to actuate the jaws to close the clip. The various spring and trigger mechanisms operate to keep the clip adequately supported and provide enough force for closing. As has been described, there are numerous safety and redundant systems so that closure is assured. Therefore, while many objects and features have been described, the invention is defined in the attached claims.

Claims: An endoscopic multiple ligating clip applier comprising: a clip applying mechanism including a pair of jaws (11a, 11b), a firing mechanism (25) held remotely from said clip applying mechanism by a support tube (15), said support tube (15) being provided with an open channel (122) communicating with a vent (120), to allow fluid to be vented from said ligating clip applier, and a feeder mechanism including a feed bar (9) for feeding ligating clips (8) to said clip applying mechanism, the feed bar (9) having outer edges (130) which contact inner edges (136) of said jaws (11a, 11b) when said feed bar (9) is advanced towards said clip applying mechanism, whereby inadvertent closure of said jaws (11a, 11b) during their insertion into the cannula (105) of a trocar is prevented. A clip applier according to claim 1, wherein said feed bar (9) comprises a pair of protrusions (132) for preventing longitudinal movement of the ligating clips (8) during its insertion into the cannula (105) of a trocar. A clip applier according to any preceding claim wherein said jaws (11a, 11b) are closed by means of a cam channel (12) having opposed internal surfaces which bear on outer surfaces of said jaws (11a, 11b) when said cam channel (12) is advanced toward the distal end (178) of said jaws (11a, 11b). A clip applier according to claim 3, wherein said means (144) for retaining said jaws (11a, 11b) in an open position comprise tabs in said cam channel (12). A clip applier according to any preceding claim, comprising a lockout lever (6) to prevent movement of said feed bar (9) towards said clip applying mechanism when no ligating clips remain in said ligating clip applier. A clip applier according to any preceding claim, comprising a clip retaining mechanism (156) for minimizing rearward movement of the clip (8) in the clip applier during closure of said jaws (11a, 11b). A clip applier according to any preceding claim, wherein said jaws (11a, 11b) are so shaped as to contact at their distal end (178) and at a point (176) located proximally to the closing ramps (172) of each jaw. A clip applier according to any preceding claim, wherein the jaws (11a, 11b) comprise opposing posts (174) which contact with each other near the forming areas of the jaws upon closure of said jaws. A clip applier according to any preceding claim, comprising a valve (182) for holding stationary all but the forwardmost ligating clip (8) of a stack of clips. A clip applier according to any preceding claim, comprising a sealing system (190, 192, 194) for maintaining pneumoperitoneum during use of the applier. A clip applier according to any preceding claim having a tissue stop (220) for ensuring that ligating clips (8) are closed to the proper gap size.

Inventors: BURBANK JOHN E, MURRAY MICHAEL A, NOBIS RUDOLPH H, RECKELHOFF JEROME E, STEFANCHIK DAVID, BURBANK, JOHN E., MURRAY, MICHAEL A., NOBIS, RUDOLPH H., RECKELHOFF, JEROME E., STEFANCHIK, DAVID
Applicants: ETHICON INC, ETHICON, INC.
Application year: 1992
Main classification: A61B17
IPC codes: A61B17