CA2462319C - Surgical jaw assembly with increased mechanical advantage - Google Patents

Abstract

A flexible clip applier includes a ratchet mechanism adapted to locate a clip pusher to a known location after deployment of a distalmost clip. In addition, the clip applier includes a flexible housing into which a train of clips may be chambered. The flexible housing is constrained from elongation when subject to tensile forces. In accord with another aspect of the invention, the jaw assembly is adapted to have relatively high mechanical leverage which facilitates tissue compression prior to application of a clip.

Description

.2 1. Field of the Invention 6 This invention relates broadly to surgical 7 instruments. Particularly, this invention relates'to 8 flexible endoscopic instruments for use through an 9 endoscope. More particularly, this invention relates to a surgical clip applier which is adapted for use through an 11 endoscope and may be used to clamp and/or suture, ducts, 12 vessels, and other tissues, to anchor a tissue, or to 13 attach a foreign body to a tissue.

2. State of the Art 16 Surgical clips are generally used to apply clamping 17 force to ducts, vessels, and other tissues. In addition, 18 surgical clips are particularly useful in controlling 19 bleeding of a tissue in lieu of suturing or stapling where suturing or stapling is difficult.

22 All of the currently available surgical multi-firing 23 clip appliers are substantially rigid devices intended to 1 extend through a trocar port or through an incision to a 2 surgical site requiring application of a clip. The devices 3 have been rigid because a stiff pushing element has been 4 required in order to exert the required pushing force to move the clip over the tissue.

7 However, there is a substantial need for a flexible 8 clip applier, particularly one insertable through a lumen 9 of an endoscope. The ability to apply clips through an endoscope would permit myriad minimally invasive surgical 11 solutions to medical problems, especially those of the 12 gastrointestinal tract. However, it is accepted theory 13 that the transmitted force required to advance or form a 14 clip over tissue cannot be produced in the distalmost end of a long flexible device that is commonly constructed with 16 a metal tubular coil, or polymer tube, such as an 17 endoscopic device or catheter. For example, C. Paul Swain, 18 MD, a recognized expert in endoscopic instruments and 19 particularly endoscopic stapling devices, has stated that "[i)t is hard to exert more than 200g of force on the 21 tissue when pushing . . .. This fact is of course one 22 feature that makes intervention at flexible endoscopy 23 relatively safe". See C. Paul Swain, "What Endoscopic 1 Accessories Do We Really Need?", Emerging Technologies in 2 Gastrointestinal Endoscopy, Gastrointest. Endosc., Vol. 7, 3 No. 2, pp. 313-330 (April 1997). Yet, a pushing force 4 substantially greater than 200g is required to push a clip over compressed tissue. In fact, it is believed a force in 6 excess of 500 grams (1.1 lbs) is required for a 7 satisfactory instrument, and substantially greater. forces, 8 e.g., in excess of 1500 grams (3.3 lbs) would be desirable.

Generally a flexible endoscopic device (e.g., a biopsy 11 forceps device) includes an outer tubular member,'typically 12 being constructed of a metal tubular coil or a polymer tube 13 which is poor in transmitting forces that impart tensile 14 stresses to the outer tubular member, a control element longitudinally movable relative to the tubular member, an 16 end effector coupled to the distal ends of both the tubular 17 member and the control element such that relative' movement 18 of the control element and the tubular member causes 19 operation of the end effector, and a handle which moves the control element relative to the handle.

22 This type of flexible endoscopic instrument is limited 23 in the amount of pushing force it can generate for several 1 reasons. Compression of a flexible control element 2 (pushing element) tends to cause the pushing element to 3 buckle within the outer flexible sheath of the device. If 4 a relatively larger diameter flexible pushing element is used such that it better resists buckling, the pushing 6 element may impart too much stiffness to the flexing of the 7 endoscopic instrument. In addition, a flexible pushing 8 element of larger diameter is subject to greater frictional 9 forces within the outer sheath which reduces the force transmitted from the handle to the end effector. If the 11 flexible pushing element is made relatively smaller in 12 diameter, it is subject to kinking which will result in 13 little to no force transmitted to the distal end. Kinking 14 is especially a problem in endoscopic instruments, as the endoscope and its lumen may be extended through a tortuous 16 path. For these reasons and others, mechanical application 17 of a relatively large distal end pushing force and 18 particularly clip application have been absent from the 19 capability of flexible endoscopic tools.

21 In addition, it is important that the tissue about 22 which a clip is to be applied be substantially compressed.
23 While the jaws apply a clamping force which compresses the I tissue, large clamping forces are difficult to achieve due 2 to the dimensions of the relatively small jaw assembly.

3 That is, the dimensions are such that the lever arm between 4 a pivot of the jaw assembly and each jaw tang is relatively short, limiting the mechanical leverage on the jaw 6 assembly.

It is therefore an object of the invention to provide 11 a flexible endoscopic device capable of being subject to 12 large tensile forces.

14 It is also an object of the invention to provide a flexible endoscopic device capable of generating a 16 relatively large clamping force at its jaw assembly.

18 It is another object of the invention to provide a 19 flexible endoscopic device having a jaw assembly with increased mechanical advantage.

p 1 it is a further object of the invention to provide a -2 flexible endoscopic device which has a reliable ratchet 3 mechanism at its distal end.

It is an additional object of the invention to provide 6 a flexible endoscopic clip applier which is adapted to 7 store a plurality of clips and which can controllably 8 dispense the clips one at a time over compressed tissue.

It is yet another object of the invention to provide a 11 flexible endoscopic clip applier which is torqueable.

13 In accord with these objects, which will be discussed 14 in detail below, a surgical clip applier is provided having a flexible, preferably flat wire wound outer tubular coil, 16 a pair of jaws rotatable about a clevis at the distal end 17 of the tubular coil, a set of end effector wires extending 18 through the outer tubular coil and coupled to the jaws, and 19 a clip-advancing wire extending through the tubular coil.
A lubricious, preferably extruded polymer, multilumen 21 barrier sheath extends within the tubular coil and 22 separates the wires from each other and the tubular coil.

1 A clip chamber is provided in the distal end of the 2 tubular coil and stores a plurality of linearly arranged 3 clips. According to one embodiment of the clip chamber, 4 the clip chamber comprises a separate tubular member coupled to the distal end of the tubular coil. The 6 separate tubular member may be another coil, and preferably 7 a flat wound coil, or may be a helically cut tube in which 8 each helical winding is interlocked with an adjacent 9 winding such that the tube is flexible yet will not elongate when subject to tensile force.

12 A clip pusher is provided at a distal end of the clip-13 advancing wire, and adapted to advance the clips in the 14 chamber toward the jaws when the clip-advancing wire is advanced through the barrier sheath and outer tubular coil.
16 According to a preferred aspect of the invention, the clip 17 pusher and clip chamber cooperate to provide a ratchet 18 mechanism whereby clips may be distally advanced 19 therethrough but are prevented from proximal retraction through,more than a predefined distance. Thus, the clip 21 pusher and clips in the chamber can be withdrawn to 22 respective known positions after the successive deployment 23 of a distalmost clip. This permits the clip pusher to be S

1 located at a known position within the clip chamber 2 regardless of the degree of flexion to which the endoscopic 3 clip applier is subject. According to a first embodiment 4 of the ratchet mechanism, notches are provided in the clip-advancing wire and a resilient catch is provided to a 6 keyhole element within the tubular coil. The clip-7 advancing wire may be moved distally relative to the catch, 8 but the catch limits retraction of the clip-advancing wire.
9 According to a second embodiment of the ratchet mechanism, a ratchet structure is provided to the,clip-advancing wire 11 and a pawl is fixed to a mount which-is longitudinally 12 disposed between two sections of the outer tubular member, 13 i.e., the coil and the clip chamber. According to a third 14 embodiment of the ratchet mechanism, two longitudinally extending brackets are disposed within a distal portion of 16 the outer tubular member. The brackets include flexible 17 arms which extend into the chamber and limit retraction of 18 the clip pusher after advancement past a pair of the arms.
19 As such, each ratchet mechanism controllably locates the pusher within the outer tubular member. In addition, in 21 each of the embodiments, structure is provided to permit 22 transmission of torque from the clip-advancing wire or clip 1 pusher to the outer tubular member, and thus the jaw 2 assembly.

4 The jaws include clamping surfaces which operate to compress tissue between the jaws when the jaws are closed, 6 guides in which a distalmost clip rides distally and is 7 advanced over the clamped tissue when the line of clips is 8 advanced by the clip pusher, and a distal anvil which 9 operates to bend a portion of the distalmost clip to enhance its retention on the clamped tissue. According to 11 a preferred aspect of the invention, portions of the jaws 12 and the clevis define a circumferential ridge of greater 13 diameter than the remainder of the jaws and clevis. This 14 ridge operates to permit the pivot axis of the jaws and the tang holes of the jaws (at which the control wires are 16 coupled to the tang of the jaws) to be moved further apart 17 than otherwise possible to effect substantially greater 18 mechanical advantage in closing the jaws.

A proximal handle is provided for movement - of the 21 clip-advancing wire and end effector wires relative to the 22 barrier sheath to effect (1) clamping and rotation of the 23 jaws (relative to each other and about the longitudinal 9 _ 1 axis of the tubular coil), and (2) advancement of the clip-2 advancing wire to effect distal movement of a clip.

4 The flat wire wound tubular coil is preferred over round wire (though not necessarily required over a round 6 wire wound tubular coil) because it is flexible, yet 7 sufficiently longitudinally stiff such that the device may 8 be pushed through the lumen of the endoscope. In addition, 9 the flat wire wound tubular coil can be made with a high preload and has a tensile spring constant sufficiently high 11 that it resists buckling and uncoiling during application 12 of a pushing force by the handle against the clip-advancing 13 wire. The clip-advancing wire has a sufficiently large 14 diameter to transmit force, yet small enough to minimize internal friction when moved within a device flexed through 16 a tortuous path in an endoscope. The end effector wires 17 are large enough to handle the high closing force from the 18 handle, and to resist compressive buckling when moved in an 19 opposite direction, yet small enough to be coupled to diminutive jaws. The multilumen barrier sheath supports 21 the clip- advancing wire and end effector wires along their 22 length to reduce compressive buckling, and provides a 23 separation layer to reduce friction. Movement of the clip--I advancing wire relative to the outer tubular coil causes a 2 compressive force in the clip-advancing wire and tensile 3 forces in the outer tubular member such that a relative 4 pushing force is transmitted to the distal end of the clip-advancing wire in excess of the perceived threshold of the 6 200 grams (0.44 lbs). In fact, one embodiment of the 7 device of the invention, sized for endoscopic use, provides 8 a pushing force in excess of 2267 grams (5 lbs).

In operation, the jaws can be moved through a working 11 channel of an endoscope in a closed position. Once exited, 12 the handle can be operated to open the jaws and rotate the 13 jaws to a desired orientation. The jaws are positioned on 14 either side of tissue about which it is desired to place a clip and the handle is operated to pull the end effector 16 wires such that the jaws clamp about the tissue. The 17 handle is then locked to maintain the jaws in the clamped 18 position. The handle is operated to effect advancement of 19 the clip-advancing wire through the tubular coil such that a clip is advanced through the jaw guides and over the 21 tissue. The clip is advanced until a portion thereof is 22 forced against the anvil of the jaws to effect bending of 23 the clip portion such that that portion moves laterally to 1 pierce the clamped tissue. After the clip is applied, the 2 jaws are released from about the tissue, and the end 3 effector assembly may then be moved to another tissue 4 location to apply additional clips.

6 Additional objects and advantages of the invention 7 will become apparent to those skilled in the art upon 8 reference to the detailed description taken in conjunction 9 with the provided figures.

13 Fig. 1 is a partial section side elevation view of a 14 surgical clip applier according to the invention, shown with the handle configured to provide the jaws in an open 16 configuration;

18 Fig. 2 is a broken perspective view of a distal 19 portion of the clip applier according to the invention;

21 Fig. 2A is an exploded and broken perspective view of 22 a distal portion of the clip applier according to the 23 invention;

2 Fig. 2B is a broken schematic view of a distal end of 3 the clip-advancing wire and the coil connector;

Fig. 2C is a broken schematic view of a distal end of 6 the clip-advancing wire and the coil connector illustrating 7 the limitation on proximal movement of the clip-advancing 8 wire relative to the coil connector;

Fig. 3 is a perspective view of the jaw assembly of 11 the clip applier according to the invention, and a clip;

13 Fig. 4 is a partial section side elevation view of a 14 surgical clip applier according to the invention, showing the right side of the handle positioned to place the jaws 16 in an unloaded closed configuration;

18 Fig. 4A is a view similar to Fig. 4, illustrating 19 alternative embodiments to the handle of the clip applier according to the invention;

r 1 Fig. 5 is an enlarged view of the handle of the 2 surgical clip applier with the handle in the same position 3 as shown in Fig. 4;

Fig. 6 is a view similar to Fig. 4 of the left side of 6 the handle;

8 Fig. 7 is a view similar to Fig. 6 with the addition 9 of the various springs;

11 Fig. 8 is an enlarged broken section view of the 12 proximal left side of the handle of the clip applier 13 according to the invention;

Fig. 9 is an enlarged side perspective view of the end 16 effector assembly;

18 Fig. 10 is an enlarged distal end perspective view of 19 the end effector assembly;

21 Fig. 11 is a broken partial section side elevation 22 view of the distal end of the clip applier according to the 23 invention;

2 Fig. 12 is a view similar to Fig. 1, showing the 3 handle configured such that the jaws are in a unloaded 4 closed position, and shown without the pinion on the jaw closing lever;

7 Fig. 13 is a partial section perspective view of a 8 surgical clip applier according to the invention, 9 illustrating rotation of the end effector assembly by operation of the rotation knob;

12 Fig. 14 is a partial section side elevation view of a 13 surgical clip applier according to the invention, showing 14 the jaws in a clamped configuration;

16 Fig. 15 is a partial section side elevation view of a 17 surgical clip applier according to the invention, showing 18 the jaws in a clamped configuration and the clip-advancing 19 lever actuated;

21 Fig. 16 is an enlarged partial section view of the 22 handle of the surgical clip applier, showing the clip-23 advancing lever actuated;

2 Fig. 17 is a longitudinal section view of the distal 3 end of the clip applier according to the invention, shown 4 with the jaws in a closed configuration and a formed clip therebetween;

7 Fig. 18 is a broken partial section side elevation 8 view of the distal end of the clip applier according to the 9 invention, shown with the jaws in an open configuration and a formed clip therebetween;

12 Fig. 19 is a broken partial section side elevation 13 view of the distal end of the clip applier according to the 14 invention, shown with the jaws in an open configuration, the formed clip released, and the retainer of a subsequent 16 clip protruding between the jaws;

18 Fig. 20 is a longitudinal section view of the distal 19 end of the clip applier according to the invention, shown with the jaws in an open configuration and the retainer 21 retracted relative to the view of Fig. 19;

j 1 Fig. 21 is a partial section side elevation view of a 2 surgical clip applier according to the invention, shown 3 with the jaws in an open position and a formed clip 4 released therefrom;

6 Fig. 22 is a table listing dimensions for the tubular 7 coil, clip-advancing wire, and end effector wires of six 8 prototypes, and the resultant output force achieved with 9 the prototype;

11 Fig. 23 is an efficiency plot of the prototypes 12 described in the table of Fig. 22;

14 Fig. 24 is a broken perspective view of a distal end of clip applier device of the invention, showing second 16 embodiments of a ratchet mechanism and clip chamber 17 according to the invention;

19 Fig. 25 is an enlarged broken perspective view of a portion of the ratchet mechanism of Fig. 24;

22 Fig. 26 is a partial broken perspective view of a 23 distal end of clip applier device of the invention, showing ` a a 1 the second embodiments of a ratchet mechanism and clip 2 chamber according to the invention;

4 Fig. 27 is an enlarged partial broken perspective view of a portion of the ratchet mechanism and clip chamber of 6 Fig. 26;

8 Fig. 28 is a side elevation of helical cut metal tube 9 for use as a clip chamber in accord with the invention;

11 Fig. 29 is an end view of the metal tube of Fig. 28, 12 with a clip shown within in broken lines;

14 Fig. 30 is a partial broken perspective view of a third embodiment of a ratchet mechanism and clip chamber, 16 as well as an alternate jaw assembly according to the 17 invention;

19 Fig. 31 is a partial broken exploded perspective view similar to Fig. 30;

1 Fig. 32 is a perspective view of the alternate jaw 2 assembly according to the invention, with the jaws shown in 3 an open position; and Fig. 33 is a perspective view of the alternate jaw 6 assembly according to the invention, with the jaws shown in 7 a closed position.

11 Turning now to Figs. 1, 2, 2A and 3, an embodiment of 12 a flexible clip applier 10 according to the invention 13 suitable for insertion through a working channel (lumen) of 14 an endoscope is shown. The clip applier 10 generally includes a flexible, flat wire wound outer tubular coil 12 16 having an end effector assembly 13 mounted at a distal end 17 16 thereof. The end effector assembly 13 includes a clevis 18 (jaw mount) 14 rotatably supporting a pair of jaws 18, 20.
19 End effector wires 22, 24 extend through the tubular coil 12 and have distal ends 26 respectively coupled to the jaws 21 18, 20. A clip-advancing wire 30 extends through the 22 tubular coil 12 and includes a distal end 32 provided with 23 a clip pusher 34. A lubricious, preferably extruded, I multilumen barrier sheath 36 extends through substantially 2 the entire length of the outer tubular coil 12 and 3 separates the end effector wires 22, 24 and clip-advancing 4 wire 30 from each other and the outer tubular coil 12. A
proximal handle assembly 40 is provided for moving the end 6 effector wires 22, 24 and clip-advancing wire 30 relative 7 to the tubular coil 12 to effect clamping and rotation of 8 the jaws and advancement of a clip, as described in detail 9 below.

11 Referring to Figs. 4 and 5, more particularly, the 12 handle assembly 40 includes a housing defined by two shell 13 portions 42, 44, a stationary handle 46, a jaw closing 14 lever 48 linearly movable within a slot.50 in the housing and relative to the stationary handle 46, and a clip-16 advancing lever 52 rotatably mounted on the jaw closing 17 lever 48 with a pivot pin 54. The jaw closing lever 48 is 18 coupled to the end effector wires 22, 24, as described in 19 detail below. The jaw closing lever 48 is biased into an open position (away from the stationary handle 46) with a 21 constant force spring 56 held in a distal portion of the 22 housing such that the jaws 18, 20 are in an open 23 configuration when no manual force is applied against the I force of the spring 56 to move the jaw closing.lever toward 2 the stationary handle. The clip-advancing lever 52 is 3 forced into an open position, also away from the stationary 4 handle 46, with a torsion spring 58 (Figs. 4 and 7). The clip-advancing lever 52 is coupled to the clip-advancing 6 wire 30, as discussed in detail below, with rotation of the 7 clip-advancing lever 52 operating to move the clip pusher 8 34 at the distal end 32 of the clip-advancing wire 30 9 longitudinally within the tubular coil.

11 A tube 60 extends from the interior of the handle 40 12 to the exterior and includes a proximal rotation knob 62.
13 The proximal end of the clip-advancing wire 30 is clamped, 14 or otherwise held, within the tube 60 such that rotation of the knob 62 causes rotation of the entire clip-advancing 16 wire. A distal end 64 of the tube 60 is rotatably coupled 17 within a collar 66. The collar 66 is fixedly coupled to a 18 rack 68. Linear movement of the rack 68 within the housing 19 causes the tube to move longitudinally within and outside the housing.

22 Alternatively, referring to Fig. 4A, the tube 60 may 23 be telescoping, having two rotationally interfering I sections 60a and 60b, such that movement of the rack 68 2 moves a distal section 60a of the tube relative to a 3 proximal section 60b, thereby maintaining a constant length 4 for extension of the proximal section 60b of the tube outside the housing. The rotationally interfering 6 portions, e.g., each having a hex shape, permit 7 rotationally forces to be transmitted from the knob' 62 to 8 the distal end 64 of the tube.

Referring back to Fig. 4, a pinion 70 is rotatably 11 mounted at 72 to an upper portion 74 of the clip-advancing 12 lever 52 and positioned to act on the rack 68 when the 13 clip-advancing lever is rotated. As such, when the clip-14 advancing lever 52 is rotated about pivot 54 toward the jaw closing lever 48, the rack 68 and the clip-advancing wire 16 30 are advanced. The rack 68 is preferably substantially 17 longer than what is required by the number of teeth on the 18 pinion 70. As a result, the pinion 70 can act upon the 19 rack 68 in any location at which the jaw closing lever 48 may be positioned upon closing the jaws 18, 20. Thus, when 21 the jaw closing lever 48 is pulled back toward the 22 stationary handle 46 to effect closure of the jaws 18, 20 23 about tissue, the jaw closing lever 48 may be located at a 1 location which is consistent with the thickness and 2 consistency of the tissue about which the jaws are to be 3 closed.

The teeth of the pinion 70 are preferably at a 6 positive engagement angle relative to the teeth of the rack 7 68 because of the location of the pinion pivot axis 72.

8 Then, when the pinion is rotated, the rack is moved 9 longitudinally. A leaf spring 76 acts between the pinion 70, at hole 78, and the advancing lever 52 at shelf 77 to 11 force the pinion 70 into the rack 68. After firing a clip, 12 as discussed below, release of the clip-advancing lever 52 13 allows the spring 58 to return the lever 52 back to.its 14 unbiased position, and the pinion 70 rotates about the pinion axis 72 against the leaf spring 76 and over the rack 16 68.

18 Turning now to Figs. 6 through 8, the jaw closing 19 lever 48 includes a spring activated catch system 80 which locks the jaw closing lever when a predetermined load is 21 applied thereto rather than when the closing lever is 22 located at any particular location. The catch system 80 23 includes the following structures on an upper mount portion 1 82 of the jaw closing lever 48: a proximal spring mount 84;
2 two spaced apart bolts 86, 88; and a locking tooth 90. The 3 locking tooth 90 includes a proximal cam 92. The catch 4 system 80 further includes the following additional structures: a latch 94 having a linear slot 96 and a cam 6 slot 98, which are positioned over bolts 86, 88 7 respectively; an end effector wire mount 100 to which the 8 proximal ends of the end effector wires 22, 24 are 9 attached; an upper cam surface 102 for the below-described lever lock 110; and a spring catch 104. An extension 11 spring 106 (Fig. 7) is held between the spring mount 84 and 12 spring catch 104. A generally L-shaped lever lock 110 is 13 rotatably coupled about a lever pivot 114 formed at the 14 proximal end of the handle. An elongate portion 116 of the lock 110 includes a comb;. i.e., the portion 116 includes a 16 plurality of teeth 118, each of which include a distal 17 camming surface 120. Another portion 122 of the lever lock 18 110 is provided with a release button 124 which extends 19 outside of the handle housing. A torsion spring 130 is provided about the pivot 114 to bias the lever lock 110 21 down toward'the locking tooth 90. A safety 132 is also 22 provided to prevent release of the jaw closing lever 48 23 when the clip-advancing lever 52 is moved from an unbiased t j 1 position, thereby preventing inadvertent release of 2 unapplied clips.

4 Once the jaws are closed about tissue, as discussed further below, it is desired to maintain their closed 6 position until a clip is advanced over the tissue. In view 7 of this object, the catch system 80 function as follows.

8 Still referring to Figs. 6 through 8, the cam surface 102 9 is generally adapted to position the teeth 118 of the lever lock 110 located in front of the locking tooth 90 above the 11 locking tooth, such that the jaw closing lever 48 may be 12 moved linearly. When the jaw closing lever 48 is moved 13 toward the stationary lever 46, tension is increased in the 14 end effector wires 22, 24 to move the jaws 18, 20 from an open position to a closed position. As the tension 16 increases in the end effector wires 22, 24 and exceeds the 17 tension of the extension spring 106, the latch 94 moves 18 distally relative to the jaw closing lever 48. Then, 19 movement of the jaw closing lever 48 relative to the latch 94 causes the bolts 86, 88 to ride within the linear slot 21 96 and the caroming slot 98, respectively. Referring to 22 Fig. 8, movement of bolt 88 within camming slot 98 forces 23 the proximal end of the latch 94 downward and permits the I lever lock 110 to rotate clockwise. This causes the 2 locking tooth 90 to engage the toothed portion 116 of the 3 lever lock 110 and lock the position of the jaw closing 4 lever 48. The load applied to the end effector wires is then limited to the force applied by the extension spring 6 106 (Fig. 7). The jaw closing lever 48 then may be 7 released by pushing the release button 124 sufficiently to 8 rotate the lever lock 110 against the bias of the torsion 9 spring 130 and clear the locking tooth 90.

11 Turning now to Figs. 1, 2, 4 and 6, the distal end of 12 the housing 42, 44 of the handle assembly 40 includes a 13 slot 131 in which two preferably substantially rigid and 14 preferably low friction tubes 133, 135, e.g., brass tubes, are provided. The proximal end 136 of the tubular coil 12 16 is coupled to the housing in alignment with the tubes 133, 17 135 with a flare nut coupling 138 or an equivalent 18 assembly. The clip-advancing wire 30 extends from the 19 rotation tube 60 through tube 133 and into a clip-advancing wire lumen 140 of the barrier sheath 36. The clip-21 advancing wire 30 extends therethrough to the distal end 16 22 of the tubular coil 12. The end effector wires 22, 24 23 extend from end effector wire mount 100 through tube 135 f {

1 and into respective end effector wire lumina 142, 144 of 2 the barrier sheath 36, and then extend therethrough to the 3 distal end of the tubular coil. Wires 22, 24 and 30 are 4 provided in separate lumina within the barrier sheath 36 in order to minimize friction between the wires and reduce 6 buckling and kinking of the wires along the length of the 7 tubular coil 12.

9 Turning again to Fig. 4A, rather than using tubes to direct the wires from the housing into the barrier sheath 11 in tubular coil, the housing may be formed with channels 12 which provide the same function. For example, channels 13 132a, 132b are adapted to direct the clip-advancing wire 30 14 and end effector wires 22, 24, respectively, into the barrier sheath 36 within the tubular coil 12. In addition, 16 the housing may be formed with distal structure, e.g., a 17 cylindrical protrusion 146, facilitating the coupling of a 18 flare nut assembly thereto.

Referring back to Fig. 2, the tubular coil 12 is a 21 preferably stainless steel (or other metal or metal alloy) 22 flat wire wound wire tubular coil, though a round wire 23 wound tubular coil may be used. The tubular coil 12 is 1 fairly stiff such that the device can be pushed through the 2 endoscope to the treatment area. The tubular coil 12 has a 3 spring constant sufficiently high in order to resist 4 uncoiling when subject to the tensile load created when the handle applies a pushing force to the clip-advancing wire 6 and the clips, as discussed in more detail below, and 7 minimize buckling during force transmission. In addition, 8 the tubular coil 12 is preloaded such that each turn is 9 substantially in contact with the adjacent turns 3600 around the tubular coil. The outer diameter of the tubular 11 coil 12 has an outer diameter smaller than the inner 12 diameter of the working channel (lumen) of an endoscope for 13 which it is intended, and the inner diameter of the tubular 14 coil should be maximized so that it may readily accept the barrier sheath, and clip-advancing wire and end effector 16 wires, as well as clips, as discussed below. In preferred 17 embodiments, the tubular coil 12 of a device adapted for an 18 endoscope having a 3.2 mm working channel has an outer 19 diameter preferably not exceeding approximately 3.175 mm (0.125 inch), and a preferably an inner diameter of at 21 least approximately 0.90 mm (0.035 inch) so that it may 22 accept the end effector wires 22, 24, clip-advancing wire 23 30, barrier sheath 36, and clips 202. That is, as shown in I Fig. 11, the distal end of the coil defines a clip chamber 2 200 for storing a train of clips 202, as discussed in more 3 detail below. The inner diameter of the coil 12 4 preferably corresponds to the transverse dimension of a clip 202, discussed below, so that the clip is stably 6 directed through the chamber-200. The wire of the tubular 7 coil 12 has a width W preferably between approximately 8 0.635 mm to 1.270 mm (0.025 inch to 0.050 inch), and a 9 thickness T preferably at least approximately 0.13 mm to 0.75 mm (0.005 inch to 0.030 inch). The tubular coil 11 length should at least be the length-of the endoscope 12 working channel, generally 150 cm to 250 cm. A substantial 13 length of the tubular coil 12 is preferably covered in a 14 high density polyethylene (HDPE) sheath 150 (Figs. 1, 2 and 2A).

17 The barrier sheath 36 within the tubular coil is 18 preferably non-circular in shape to reduce contact points 19 and thereby minimize friction between the barrier sheath and the tubular coil. The primary purpose of the sheath is 21 to maintain a close fitting bearing surface for the clip-22 advancing wire, although its three distinct lumina help 23 reduce friction between all the wires. The sheath 36 I preferably free floats within the tubular coil; i.e., it is 2 not attached to the tubular coil at its ends or along its 3 length. Preferred cross-sectional shapes include generally 4 rectangular and triangular (each with or without broken or rounded edges) and trefoil. The barrier sheath 36 is 6 preferably an extrusion made from polypropylene, an FEP

7 fluoropolymer resin (FEP), polytetrafluoroethylene'(PTFE), 8 high density polyethylene (HDPE), nitrol polyvinyl 9 chloride, nylon, or any other lubricious polymer.

11 The clip-advancing wire 30 is preferably made of 12 nickel-titanium alloy (NiTi) or stainless steel. The NiTi 13 construction permits the clip-advancing wire 30 to transmit 14 torque (by rotation of the rotation knob 62) without taking a cast, and with minimal whipping. The clip-advancing wire 16 30 has a sufficiently large diameter to transmit force, yet 17 not so large that it is prevented from functioning through 18 a tortuous path or fit within the tubular coil 12. A

19 preferred diameter for the clip-advancing wire is approximately 0.375 mm to 0.89 mm (0.015 inch to 0.035 21 inch).

1 Referring to Figs. 2, 2A and 2B, the distal end 32 of 2 the clip-advancing wire 30 has a non-circular cross-3 section, and is preferably rectangular in shape. The 4 distal end 32 is preferably a length four to five times the length of the clip pusher 34. A coil connector 152 is 6 coupled within the distal portion 16 of the tubular coil 7 12, e.g., by welding, press fitting, interference fit, 8 pinning, etc., preferably approximately 25 mm to 50 mm from 9 the distal end of the tubular coil (i.e., the length of a linear arrangement of five or so clips), and includes a 11 central keyhole 156 having a non-circular cross section, 12 and two end effector channels 158 (only one shown) through 13 which the end effector wires 22, 24 extend. The distal end 14 32 of the clip-advancing wire 30 can be longitudinally moved through the keyhole 156, with the transition 159 of 16 the clip-advancing wire 30 from non-circular to circular 17 outer shape functioning as a stop against the keyhole 156 18 for additional distal movement.

In the flexible clip applier 10 there is a need to 21 know the precise location of the clip pusher 34. This is 22 rendered difficult by a bending of the device, which alters 23 the relative positions of the clip-advancing wire 30 1 relative to the coil 12. Thus, referring to Fig. 2B, the 2 distal end 32 of the clip-advancing wire 30 also includes a 3 ratchet mechanism partially defined by notches 250 along 4 one side 251 of the distal end 32 which have a distal surface 252 substantially perpendicular to the side 251 and 6 proximal beveled surface 254. The ratchet mechanism is 7 also defined by a resilient pawl 256 on the coil connector 8 152. The pawl 256 is in alignment with the notches 250.

9 When the clip-advancing wire 30 is moved distally through the keyhole 156, the pawl 256 rides against the beveled 11 surface 254 of the notches 250, and bends for clearance.

12 However, as distal surface 252 interferes with the pawl 256 13 when the clip-advancing wire 30 is moved proximally 14 relative to the coil connector 152, the clip-advancing wire 30 may not be moved proximally by a distance which would 16 cause a notch 250 to pass the pawl 256 (Fig. 2C). As such, 17 after distal advancement of the clip-advancing wire and 18 clip pusher and deployment of a clip, proximal retraction 19 of the clip-advancing wire and clip pusher references the clip pusher to a precise predefined location.

1 Moreover, rotation of the clip-advancing wire 30 2 causes a rotational moment to be applied to the connector 3 152 and consequently the distal end of the tubular coil 12.
4 The distal end of the preloaded tubular coil 12 can be thereby rotated 360 in each of the clockwise and 6 counterclockwise directions by rotation of the rotation 7 knob 62 attached to the proximal end of the clip-advancing 8 wire 30. Because the end effector assembly 13 is attached 9 to the distal end of the tubular coil, rotation of knob 62 effects rotation of the end effector assembly 13 and the 11 jaws 18, 20.

13 The end effector wires 22, 24 are large enough in 14 diameter to preferably handle up to fifteen pounds of closing force from the handle assembly and also to handle 16 the force required to open the jaws 18, 20 without 17 buckling. However, the end effector wires must be small 18 enough in diameter to attach to the jaws, and fit in the 19 tubular coil 12. A preferred diameter for the end effector wires is approximately 0.178 mm to 0.375 mm (0.007 inch to 21 0.015 inch), though other sizes may be used.

1 Referring to Figs. 9 and 10, the clevis 14 of the end 2 effector assembly 13 is preferably coupled directly to the 3 distal end of the tubular coil 12. The clevis 14 includes 4 a central clip channel 164 having a preferably rectangular cross section, and two lateral openings 165 through which 6 the distal ends of the end effector wires 26, 28 can 7 respectively exit. The jaws 18, 20 are each rotatably 8 coupled about the clevis 14 with a respective axle 166 (one 9 shown) which does not interfere with the channel 164. Each jaw 18, 20 includes a proximal tang 16,8, 169 respectively, 11 which is coupled to the distal ends of the respective end 12 effector wires 26, 28. The distal portion of each jaw 18, 13 20 includes a clip guide 170, 172, respectively, and 14 clamping surfaces 174, 176 on jaw 18, and clamping surfaces 178, 180 on jaw 20 extending along each side of the guide 16 172. All of the clamping surfaces 174, 176, 178, 180 17 preferably have proximally directed teeth 182 which pulls 18 target tissue toward the clip channel 164 as the jaws are 19 closed, and also securely grips the tissue when a clip is advanced thereover. The distal end of jaw 18 includes an 21 anvil 184 which is in alignment with the clip guide 170 22 which curves (or is angled) toward jaw 20. Jaw 20 includes 23 two distal anvil guides 186, 188 between which the anvil 1 184 is positioned when the jaws are moved to a closed 2 position. Jaw 20 also defines a distal well 190 between 3 the anvil guides 186, 188 which is lower than the surface 4 of clip guide 172.

6 Referring to Fig. 11, the clip chamber 200 for storing 7 a plurality of linearly arranged clips 202 (Fig. 2A), 8 described further below, is formed between the coil 9 connector 152 (Figs. 2 and 2A) and the distal end 16 of the tubular coil 12. The clip chamber 200 is aligned with 11 the clip channel 164 of the clevis 14. The clip pusher 34 12 is provided at the proximal end of the chamber and situated 13 to push on a proximalmost clip such that all clips in front 14 of the clip pusher 34 are advanced toward the jaws 18, 20 when the clip-advancing lever 52 is actuated to cause the 16 clip-advancing wire 30 to move distally relative to the 17 tubular coil 12.

19 The clip pusher 34, preferably made of stainless steel, is coupled to the distal end 32 of the clip-21 advancing wire 30, e.g., by mechanical joining or welding.
22 The clip pusher 34, as described in more detail below, is 23 provided with a shape substantially similar to the distal 1 portion of a clip 202 (Fig. 2A) adapted to be used in the 2 clip applier. Such clips 202 are described in detail in 3 U.S. Patent No. 6,716,226.

4 Generally, referring to Fig. 2A, the clips 202 are each in a generally U-shaped configuration with first and second 6 arms 204, 206, and a bridge portion 208 therebetween. The 7 first arm 204 extends into a. deformable retainer 214 8 preferably having a tissue-piercing end 216 and preferably 9 also a hook 218, and the second arm 206 is provided with a tip 210 preferably having one or more catches 212. The 11 clip 202 is provided with structure that facilitates the 12 stacking (or chaining) of a plurality of clips in the clip 13 chamber 200. The structure includes: a notch 220 at a 14 junction of the second arm 206 and the bridge portion 208 which is adapted to receive the tip 210 of the second arm 16 206 of another clip; an elongate recess 222 along the 17 exterior of the-first arm 204 which is adapted to receive 18 the retainer 214 of the first arm of another clip; and an 19 interior configuration 224 at the ends of the first and second arms which corresponds to an exterior shape of the 21 proximal bridge portion 208 of another clip. In one 22 embodiment, the clips 202 are each approximately 6.86 mm 23 (0.27 inch) in length from the bridge 208 to the end of the I retainer 214, have a width of approximately 0.90 mm (0.035 2 inch), and a height of 1.80 mm (0.070 inch). However, it 3 is understood that the clip dimensions may be adapted for 4 use in devices having tubular coil inner diameters of various sizes.

7 Referring to Figs. 2 and 2A, the clip pusher 34 8 includes a rear clip seat 228 which corresponds to the 9 exterior shape of the proximal end of the clip. The clip pusher 34 also includes a distally extending arm 230 having 11 a distal clip catch 232 (adapted to seat in the recess 222 12 of clip 202), and a shoulder 234 adjacent the clip seat 228 13 on the side opposite the arm 230. As such, the clip pusher 14 34 includes structure which is adapted to conform the proximal end of a clip 202 for transferring a pushing force 16 relative to the tubular coil. In addition, the clip catch 17 232, by engaging in the recess 222 of a clip 202, prevents 18 clips from unintentionally moving distally. The clip catch 19 also permits moving a clip 202 proximally, by retracting the clip pusher 34 such that the clip catch 232 forces back 21 against wall at the rear of the recess 222 and pulls the 22 engaged clip proximally, which in turn moves other clips in 23 the `chain'. The operation of the distal portion of the 1 device 10 (including the end effector assembly 13, the clip 2 pusher 34, and the clip chamber 200) will become evident 3 with reference to the following description of the use of 4 the device 10.

6 Referring to Figs. 4 and 12, the jaw closing lever 48 7 is moved toward the stationary handle 46, against the bias 8 of spring 56, to cause the jaws 18, 20 of the end effector 9 13 to move into a closed position. Movement of the lever 48 adapts, in size, the distal end of the device for 11 delivery through the lumen (working channel) of an 12 endoscope, but preferably does not substantially load the 13 end effector wires 22, 24. Once the end effector assembly 14 13 has exited the distal end of the endoscope, the jaw closing lever 48 can be released to open the jaws (Fig. 1).
16 Referring now to Fig. 13, the proximal rotation knob 62 can 17 be rotated which, as discussed above, effects rotation of 18 the entire clip-advancing wire 30 and, hence, rotation of 19 the end effector assembly 13. Briefly, this is because the end effector assembly 13 is coupled to the tubular coil 12 21 and the tubular coil is provided with a fixed coil 22 connector 152 which is rotated by rotation of the distal 23 end 32 of the clip-advancing wire 30.

2 Turning now to Fig. 14, once the jaws 18, 20 of the 3 end effector assembly 13 are positioned on either side of 4 tissue (not shown) about which it is desired to place a clip 202 (Figs. 2 and 2A), the jaw closing lever 48 is 6 again moved toward the stationary handle 46 to clamp the 7 jaws about the tissue. The lever 48 is moved relatively 8 further than shown in Fig. 12, as the wires 22, 24 will be 9 under load to compress the tissue. Referring back to Figs.

9 and 10, the teeth 182 on the clamping surfaces 174, 176, 11 178, 180 of the jaws 18, 20 are angled proximally to pull 12 the tissue into the jaws assembly and securely hold the 13 tissue against the distally directed force of an advanced 14 clip. As the jaws close, the anvil 184 moves between the anvil guides 186, 188, and may partially or fully pierce 16 the tissue.

18 Once the jaws are fully clamped about the tissue, the 19 locking tooth 90 engages with the lever lock 110 as the latch 94 moves down to allow engagement and thereby lock 21 the jaw closing lever 48 relative to the stationary handle 22 46, as discussed above with respect to Figs. 6 and 7. As 23 discussed above, the jaws are locked based upon the load in 1 the handle, rather than at any particular position. This 2 permits locking the jaws about tissues of various 3 thicknesses and compressive properties. Moreover, it is 4 noted that when the jaws 18, 20 are fully clamped, the end effector wires 22, 24 are placed under tension which 6 provides compression to the tubular coil 12 such that the 7 coil has an effectively higher tensile limitation before 8 stretching.

Referring now to Figs. 15 and 16, after the jaws are 11 clamped about the tissue, the clip-advancing lever 52 is 12 rotated about the pivot pin 54 to effect advancement of the 13 clip-advancing wire 30 through the tubular coil 12. More 14 particularly, as lever 52 is rotated toward the jaw closing lever 48, the pinion 70 engages the rack 68 to move the 16 rack relatively distally. As the proximal end of the clip-17 advancing wire 30 is longitudinally fixed relative to the 18 rack 68, the distal end 32 of the clip-advancing wire 30 is 19 consequently moved distally. Referring to Figs. 10 and 17, the pusher 34, at the distal end 32 of the clip-advancing 21 wire 30 distally advances the clips 202a, 202b, 202c, 202d 22 in the chamber 200, and particularly forces the distalmost 23 clip 202a through the channel 164 in the clevis 14 and 1 between the jaws 18, 20. As clip 202a is further advanced, 2 the first and second arms 204, 206 ride in guides 170, 172, 3 respectively, and are forced over the tissue held between 4 the jaws 18, 20. When the retainer 214 on the first arm 204 of the clip 202a is forced against the anvil 184, the 6 retainer 214 is bent toward jaw 20; the tip 216 pierces the 7 tissue between the jaws 18, 20 (or is guided into the 8 pierce hole made by the anvil 184 when the jaws clamped the 9 tissue); and the tip 216 enters the well 190 at the distal end of jaw 20 to extends around the tip 210 of the second 11 arm 206 which overhangs the well. The hook 218 at the tip 12 216 of the retainer 214 may engage (although it does not 13 necessarily engage), the latch 212 at the distal end of the 14 second arm 206. The force provided by the clip-advancing wire 30 to advance a clip 202 over the clamped tissue, to 16 bend the retainer 214 against the anvil 184, and to force 17 the tip 216 of the retainer to pierce tissue is at least 18 500 grams (1.1 lbs), and more typically approaches 1500 19 grams (3.3 lbs) or higher.

21 Referring now to Figs. 6 and 18, after the clip is 22 applied, the jaws 18, 20 are released from about the 23 tissue. This is done by pressing the release button 124 of 1 the lever lock 110 such that the jaw closing lever 48 is 2 permitted to move relative to the stationary handle 46.

4 Referring to Fig. 19, the clip is then released from the end effector jaw assembly by moving the jaw assembly 6 relative to the applied clip 202a. The end effector 7 assembly may then be moved to another tissue location to 8 apply additional clips.

It is noted that after clip 202a is released, the 11 retainer 214b of clip 202b partially extends into the space 12 between the jaws 18, 20. If not retracted, this retainer 13 214b would obstruct positioning the jaws 18, 20 about the 14 tissue and subsequent clip application during the procedure. However, when the clip-advancing lever 52 is 16 released, torsion spring 58 (Fig. 4) operates to pull back 17 the clip-advancing wire 30 and the clip pusher 34 and 18 thereby retract the `chain' of clips. That is, the clip 19 catch 232 of the clip pusher pulls back on clip 202d, and the retainer 214d of clip 202d pulls back clip 202c, and so 21 on, until the extending retainer 214b is pulled within the 22 chamber 164 of the clevis, and the space between the jaws 23 18, 20 is cleared, as shown in Figs. 20 and 21. The clip-1 advancing wire is limited in the distance by which it can 2 be retracted; it may be retracted only so far as permitted 3 by interference of a ridge 250 on the clip-advancing wire 4 30 located just distal the catch 256 of the coil connector 152, and the catch 256 (Fig. 2B), which is constructed to 6 be approximately the length of the protruding retainer 7 214b.

9 The device may then be used to apply another clip, or the jaws may be closed and the device may be withdrawn 11 through the endoscope.

13 The resulting clip applier is capable of 14 transmitting a pushing force at the distal end of the clip-advancing wire, resulting from the compressive force 16 appliable to the clip-advancing wire and the relative 17 tensile force appliable to the outer tubular coil and end 18 effector wires, far in excess of the perceived threshold of 19 the 200 grams (0.44 lbs) in the prior art. In fact, as discussed below, one embodiment of the device of the 21 invention provides a pushing force in excess of 2267 grams 22 (5 lbs).

1 More particularly, referring to Fig. 22, a table 2 listing part dimensions of six prototype device, and the 3 resultant output forces achieved with prototype devices is 4 provided. Fig. 23 provides an efficiency plot (input pushing force v. output pushing force) for the use of the 6 prototypes. In all prototypes, the tubular coil, clip-7 advancing wire, and end effector wires are made from 8 stainless steel. Details of the table and the efficiency 9 plot are discussed below with respect to Examples 1 through 6.

13 In a first prototype, indicated by `RUN #1', `RUN #2' 14 and `RUN #3', the tubular coil 12 has an outer diameter of 0.09 inch and an inner diameter of 0.06 inch. The clip-16 advancing wire 30 has an outer diameter of 0.017 inch and 17 the end effector wires 22, 24 each have an outer diameter 18 of 0.011 inch. The proximal end of the end effector wires 19 22, 24 are pulled with 11 lbs of force which generally results'in 5 to 10 lbs of force at the distal end of the 21 end effector wires, depending on the degree to which the 22 tubular coil 12 is bent (modeled by looping the tubular 23 coil through two inch loops); i.e., frictional losses 1 reduce the transmitted force. Moreover, it is noted that 2 whatever force is transmitted to the distal end of the end 3 effector wires 22, 24, only approximately one-fifth of that 4 force is applied to the jaws, as the distance from the jaw tang 168 to the pivot 166 is relatively shorter than the 6 length of the end of the jaw (anvil 184) to the pivot 166, 7 approximately in a one to five ratio. As such, an'input 8 force of 11 lbs may results in one to two lbs of force on 9 the jaws 18, 20. Applying the pulling force simulates the in-use condition in which the pushing force is transmitted.

12 With the tubular coil 12 extending relatively straight 13 (i.e., through no loops) in `RUN #1', an input pushing 14 force of 8 lbs on the proximal end of the clip-advancing wire 30 (i.e., a pushing force of 8 lbs on the rack 68) 16 resulted in an output pushing force of 3.82 lbs (1732.7 17 grams) at the clip pusher 34 at the distal end 32 of the 18 clip-advancing wire 30. With the tubular coil 12 extending 19 through one two-inch loop in `RUN #2', an input pushing force of 8 lbs resulted in an output pushing force of 3.42 21 lbs (1551.3 grams). With the tubular coil 12 extending 22 through two two-inch loops, in `RUN #3', an input pushing 1 force of 7 lbs resulted in an output pushing force of 3.37 2 lbs (1528.6 grams).

In a second prototype, indicated by `RUN #4', the 6 diameters of the tubular coil 12 and end effector wires 22, 7 24 are the same as Example 1. However, the diameter of the 8 clip-advancing wire 30 is decreased to 0.015 inch. With 9 the tubular coil 12 extending through no loops, a six pound input pushing force resulted in an output pushing force of 11 2.11 lbs (957 grams).

14 In a third prototype, indicated by `RUN #5', `RUN #6' and `RUN #7', the diameters of the tubular coil 12 and end 16 effector wires 22, 24 are the same as Example 1. However, 17 the diameter of the clip-advancing wire 30 is increased to 18 0.02 inch. With the tubular coil 12 extending through no 19 loops in `RUN #5', an input pushing force of 8 lbs resulted in an output pushing force of 4.03 lbs (1828 grams). With 21 the tubular coil 12 extending through one two-inch loop in 22 `RUN #6', an input pushing force of 8 lbs resulted in an 23 output pushing force of 4.08 lbs (1851 grams). With the 1 tubular coil extending through two two-inch loops, in `RUN
2 #7', an input pushing force of 8 lbs resulted in an output 3 pushing force of 3.54 lbs (1605.7 grams).

6 In a fourth prototype, indicated by `RUN #8' and `RUN
7 #9', the device includes a tubular coil 12 having an outer 8 diameter of 0.086 inch and an inner diameter of .053 inch, 9 a clip-advancing wire 30 having a diameter of 0.017 inch, and end effector wires 22, 24 having diameters of 0.009 11 inch. With the tubular coil extending through no loops, an 12 input pushing force of 8 lbs resulted in 4.61 lbs (2091 13 grams) of output pushing force. With the tubular coil 14 extending through two two-inch loops, an input pushing force of 8 lbs resulted in 4.28 lbs (1941.3 grams) of 16 output pushing force.

19 In a fifth prototype, indicated by `RUN #10', the clip-advancing wire 30 and end effector wires 22, 24 of the 21 device 10 have the same diameters as Example 4. The 22 tubular coil 12 has an outer diameter of 0.086 inch and an 23 inner diameter of 0.054 inch. With the tubular coil 12 1 extending through no loops, an input pushing force of 8 lbs 2 resulted in 4.42 lbs (2004.9 grams) of output pushing 3 force.

6 In a sixth prototype, indicated by `RUN #11', the 7 clip-advancing wire 30 and end effector wires 22, 24 of the 8 device 10 have the same diameters as Example 4. The 9 tubular coil 12 has an outer diameter of 0.083 inch and an inner diameter of 0.054 inch. With the tubular coil 12 11 extending through no loops, an input pushing force of 8 lbs 12 resulted in 5.17 lbs (2345 grams) of output pushing force.

14 Other flexible clip appliers suitable for use through a relatively smaller 2.6 mm diameter endoscope have also 16 been constructed and tested. For example, one clip applier 17 has a tubular coil 12 with an outer diameter of 0.092 inch, 18 and an inner diameter of 0.060 inch, a clip-advancing wire 19 30 with a diameter of 0.022 inch, and end effector wires 22, 24 each with a diameter of 0.013 inch. The device can 21 apply a pushing force of between 3 lbs (1361 grams). and 5 22 lbs (2268 grams) depending on the number of two-inch loops 23 through which the tubular coil was wound.

2 It is therefore appreciated that other dimensions may 3 be used for devices intended for use in endoscopes having 4 working channels of other sizes. Moreover, the device may be used outside an endoscope, where it is not limited by 6 the size of the working channel.

8 There are also alternative embodiments to various 9 aspects of the device. For example, other ratchet mechanisms and clip chambers can be used. Referring to 11 Figs. 24 through 27, a second ratchet mechanism and second 12 clip chamber according to the invention is shown. The 13 ratchet mechanism includes ratchet 300 defined in the 14 distal end 302 of the clip-advancing wire 30. The ratchet 300 includes a plurality of alternating teeth 334 and 16 notches 336 defined by shoulders 338-and ramps 340. A

17 longitudinal lower slot 304 is also defined in the distal 18 end 302 of the wire. The teeth, notches, and slot may be 19 machined into the wire 30. The distal end 302 of the wire 30 is provided with a clip pusher 34. The distal end 302 21 of the wire 30 is preferably coupled to the clip pusher 34 22 by posts 342 extending through corresponding holes 344 in 23 each.

2 The distal end 16 of the coil 12 is provided with a 3 pawl mount 346. A second flexible tubular member 310, 4 approximately one to three inches in length, extends between the pawl mount 346 and the jaw assembly 13 to 6 define a clip chamber 320. The second tubular member 310 7 may be a section of a wire coil, preferably. similar in 8 construction to coil 12. Alternatively, the second tubular 9 member may be of a substantially different construction, as described in detail below with.respect to Figs. 26 and 27.
11 Regardless, the pawl mount 346 preferably has substantially 12 the same outer diameter as coil 12 and second tubular 13 member 310. The pawl mount 346 is fixedly coupled to the 14 distal end 16 of the coil 12 and the second tubular member 310, preferably by crimping or welding.

17 The pawl mount 346 defines first and second 18 circumferential grooves 348, 350. A first ring 352 is 19 provided in the first groove 348 and includes a portion extending substantially radially inward to define a 21 resilient ratchet pawl 354. The ratchet pawl 354 extends 22 into one of the notches 336 of the ratchet 300. When the 23 clip-advancing wire 30 is moved distally relative to the f 1 coil 12, the ratchet pawl 354 rides up a ramp 340 and moves 2 into a relatively proximal notch 336. When the clip-3 advancing wire 30 is moved proximally relative to the coil 4 12, the ratchet pawl 354 will abut against a distally-adjacent shoulder 338 to limit proximal movement to a 6 predetermined maximum amount regardless of the longitudinal 7 location of the clip pusher 34 within the clip chamber 320.
8 A second ring 356 is provided in the second groove 350 and 9 includes a portion extending substantially radially into the slot 304. The ratchet pawl 354 and alignment pawl 358 11 together prevent rotation of the distal end 302 of the wire 12 300 relative to the pawl mount 346. Thus, any torque 13 provided to the clip-advancing wire 300 will be transferred 14 to the mount 346 and then to the distal end 16 of the coil 12. The coil 12 will unwind when subject to the torque and 16 effect rotation of the distal end effector assembly 13 17 corresponding to the input torque.

19 Turning now to Figs. 28 and 29, an alternate construction for the second tubular member 310 is provided 21 as a one piece helically cut, e.g. by laser, metal or metal 22 alloy tube 310a. In order to constrain the cut tube 310a 23 from elongating under tensile load or from unwinding when ' 1 subject to torque, each helical turn, e.g. turn 370a, is 2 mechanically coupled to an adjacent turn, e.g. turn 372a, 3 via a bridge (or link) 374a extending from one turn 370a 4 which is permanently interlocked in a space 376a in the adjacent turn 372a. The bridges extend substantially 6 parallel to a longitudinal axis A of the tube 310a and are 7 preferably omega-shaped (Q) with a wide free end and a 8 narrow neck. As such, the mechanical interlocks are 9 similar to interlocked pieces of a jigsaw puzzle.

Preferably one or more such bridges are provided to each 11 turn. A non-integer number of bridges may be provided to 12 any turn, and a non-integer number of bridges fewer than 13 one may also be provided to one or more turns. The tube 14 310a preferably has a non-circular interior cross-sectional shape such as cruciform. Such a shape holds a train of 16 clips therein in a desired orientation. That is, clip 202 17 (shown in broken lines) and all other clips in the clip 18 chamber 320a cannot rotate about the longitudinal axis of 19 the chamber and thus will be properly aligned for advancement into the jaw assembly 13 even as the tube 310a 21 is torqued. Moreover, such shape provides lateral channels 22 378a, 379a through which control wires can be located.

1 In view of the above, the clevis 14 of the jaw 2 assembly 13 can be coupled to the distal end of the second 3 tubular member 310 (Fig. 26) or 310a (Fig. 28).

Turning now to Figs. 30 and 31, a third embodiment of 6 a ratchet mechanism is shown. The ratchet mechanism 7 includes two preferably hermaphroditic ratchet brackets 8 430, 432 provided in and coupled to the distal end 16 of 9 the coil 12. The brackets 430, 432 together define a substantially rectangular space therebetween which operates 11 as a clip chamber 420 for feeding the clip train in a set 12 orientation toward the jaw assembly 513 (an alternate 13 embodiment of jaw assembly 13, discussed in more detail 14 below). Jaw assembly 13 may also be used. The distal end of each bracket includes a post 450 adapted to engage a 16 clevis 514 of the jaw assembly 513 and properly position 17 the chamber 420. relative to the clevis. Each bracket 430, 18 432 also includes several longitudinally-displaced pairs of 19 resilient arms 434. The arms 434 are connected at their proximal ends 436 to the brackets, with their distal ends 21 438 biased into the clip chamber between the brackets. The 22 clip pusher 34 is advanceable through the clip chamber 420 23 past the arms 434 such that the arms 434 are forced 1 laterally against their bias. As the clip pusher 34 is 2 advanced past each pair of arms on the brackets 430, 432, 3 the distal ends 438 of the arms once again enter the clip 4 chamber 420 and limit retraction of the clip pusher. Thus, each time the clip-advancing wire 30 and clip pusher 34 are 6 advanced to deploy a distalmost clip 202, the clip pusher 7 34 may be retracted only to a location defined by the 8 distal ends 438 of the arms 434 proximally adjacent the 9 clip pusher.

11 Referring now to Figs. 32 and 33, an alternate 12 embodiment of a jaw assembly 513 is shown. The jaw 13 assembly is substantially similar to the jaw assembly 13, 14 with the following modifications. The proximal portion of the jaws and the distal portion of the clevis have an 16 enlarged combined circumference relative to the remainder 17 of the jaw assembly. That is, at the location of the jaw 18 pivot 566 a circumferential ridge 592 is defined by the 19 jaws 518, 520 and the clevis 514. This ridge 592 provides the jaw assembly 513 with sufficient structural integrity 21 at the location of the ridge 592 so that the jaw pivot 22 holes 594 and the jaw tang holes 596, 598 (at which control 23 wires 22, 24 are attached to the jaws) may be located 1 relatively farther apart than with respect to jaw assembly 2 13. Without the ridge 592, the jaws 518, 520 and clevis 3 514 would be unable to define the pivot and tang holes at 4 the shown locations. By locating the pivot and tang holes 594, 596, 598 at the ridge 592, the lever arm between the 6 pivot holes and the holes is increased in length, providing 7 a significant increase in mechanical advantage when opening 8 and closing jaws 518, 520. This mechanical advantage 9 facilitates compression of tissue between the jaws. Where each of the jaws 518, 520 has an overall length L of 11 approximately 0.450 inch (11.4 mm), a jaw cup length C of 12 approximately 0.364 inch (9.2 mm), and a distal diameter D1 13 of approximately 0.126 inch (3.2 mm), the diameter D2 across 14 the ridge is preferably approximately 0.138 inch (3.5 mm).
That is, the diameter D2 is preferably approximately 0.012 16 inch (0.3 mm) or slightly more than nine percent (9%) 17 larger than D1. The distance between the centers of the 18 pivot hole and the tang hole, and thus the length of the 19 lever arm LA (the vertical component) (Fig. 32), is approximately 0.066 inch (1.67 mm). In jaw assembly 13, 21 the length of the lever arm is approximately 0.043 inch 22 (1.09 mm). Thus, jaw assembly 513 provides an I approximately fifty percent increase in mechanical 2 advantage over jaw assembly 13.

4 Significantly, the diameter D2 across ridge 592 is approximately the same as the diameter of the lumen of the 6 endoscope for which the clip,applier 10 is intended; i.e. a 7 3.5 mm diameter ridge for a 3.5 mm diameter lumen. Thus, 8 the ridge is within five percent of the diameter of the 9 endoscope lumen,'and larger than the remainder of the end effector by preferably five to fifteen percent.

12 It is recognized that it would not be possible to 13 increase the mechanical advantage by increasing the entire 14 diameter of the jaw assembly to approach the diameter of the endoscope lumen, as such would result in frictional 16 forces between jaw assembly and the-lumen of the endoscope 17 which would essentially prohibit tracking the instrument 18 through the endoscope. However, by providing a relatively 19 small surface area with the relatively larger diameter, the resulting increase in frictional force is relatively small 21 so as to not substantially interfere with movement of the 22 instrument through the endoscope. For larger or smaller 23 instruments, a ridge of similar proportion (i.e., up to 1 fifteen percent greater than the remaining diameter) can 2 likewise be provided for similar advantage.

4 From the foregoing embodiments and examples, it will be appreciated that a flexible surgical clip applier, 6 suitable for use through an endoscope is hereby provided.
7 The device is capable of effecting a pushing force far in 8 excess of the previously considered limitation of 9 approximately 200 grams for a mechanical system sized to be used through an endoscope. See C. Paul Swain, "What 11 Endoscopic Accessories Do We Really Need?", Emerging 12 Technologies in Gastrointestinal Endoscopy, Gastrointest.
13 Endosc., Vol. 7, No. 2, pp. 313-330 (April 1997), discussed 14 above. This substantial force permits clips to be forced over tissue and thereby makes available clip clamping, 16 closure, and `suturing' in an endoscopic procedure.

18 There have been described and illustrated herein 19 embodiments of a flexible surgical clip applier. While particular embodiments of the invention have been 21 described, it is not intended that the invention be limited 22 thereto, as it is intended that the invention be as broad 23 in scope as the art will allow and that the specification 1 be read likewise. Thus, while particular materials have 2 been disclosed, it will be appreciated that other materials 3 can be used as well. In addition, while particular 4 dimensions have been disclosed, it will be understood that other suitable dimensions can be used as well. Also, while 6 the device has particularly been described for use in 7 endoscopic procedures, where a great need exists for such a 8 device, it will be appreciated that flexible, non-9 endoscopic devices are considered within the scope of the invention. For example, the tubular coil may have a 11 substantially shorter length and the device may be used 12 through body orifices such as the ear canal, the nasal 13 passages, and through the larynx and trachea. By way of 14 another example, elements of the device may have substantially larger dimensions and the device can be used 16 through a trocar port. Furthermore,- while both jaws are 17 shown rotatable about a clevis, it will be appreciated that 18 only one jaw need be rotatable relative to the other.

19 Also, while two clip guides, one on each jaw, are shown, it is recognized that only a single clip guide on one of the 21 jaws is required. Moreover, while the device of the 22 invention is described as having two end effector wires, it 23 will be appreciated that a single control wire may be used I which is coupled to at least one of the jaws, and the other 2 jaw may be stationary or mechanically linked to also close 3 and open upon actuation of the single end effector wire.

4 Also, while the device has been described with respect to a clip-advancing wire and end effector wires, it will be 6 appreciated that reference to the `wires' is intended to 7 also include non-metal filaments, multifilamentary=

8 constructs, such as cables, and coils. In addition, while 9 the end effector wires when subject to a tensile force create a compressive force on the tubular coil which 11 effectively increases its tensile capability to facilitate 12 pushing a clip over clamped tissue without exceeding the 13 tensile limitation of the coil, it is recognized that other 14 mechanisms may be used to increase the tensile limitation of the coil. For example, a preferably flat and preferably 16 wire ribbon may be coupled to the inside the coil. to limit 17 the amount by which the coil can be stretched.

18 Furthermore, while the ability to provide a relative high 19 pushing force at the distal end of a clip-advancing wire is disclosed with respect to a clip applier, it is recognized 21 that such capability has application to instruments other 22 than clip appliers; for example, for endoscopic staplers, 23 lithotriptors, or any other instrument where it is desired 9 ~

1 to hold tissue and apply a pushing force, such as a device 2 for tagging. It will therefore be appreciated by those 3 skilled in the art that yet other modifications could be 4 made to the provided invention without deviating from its spirit and scope as claimed.

Claims (20)

1. A jaw assembly, comprising:

a) a clevis having proximal and distal portions, said distal portion defining a,pivot axis;

b) a first jaw coupled to said clevis; and c) a second jaw having a proximal tang and being rotatably coupled to said clevis about said pivot axis, wherein said first and second jaws define a first outer diameter of said jaw assembly, and said second jaw defines a second outer diameter at a location through which said pivot axis extends larger than said first outer diameter.

2. A jaw assembly according to claim 1, wherein:

said first jaw includes a proximal tang and is rotatably coupled to said clevis about said pivot axis.

3. A jaw assembly according to claim 1, wherein:

said proximal portion of said clevis is provided with said first outer diameter.

4. A jaw assembly according to claim 1, wherein:

said second outer diameter is at least five percent larger than said first outer diameter.

5. A jaw assembly according to claim 1, wherein:

said second outer diameter is between five and fifteen percent larger than said first outer diameter.

6. A jaw assembly according to claim 1, wherein:

said second outer diameter is approximately 3.5 mm.

7. A jaw assembly comprising:

a) a clevis having proximal and distal portions;

b) a first jaw having proximal and distal portions; and c) a second jaw having proximal and distal portions, said proximal portion of said second jaw defining a pivot axis about which said second jaw is rotatable relative to said first jaw on said clevis, wherein said proximal portions of said first and second jaws define a circumferential ridge about said jaw assembly extending radially beyond said distal portions of said first and second jaws.

8. A jaw assembly according to claim 7, wherein:
said ridge extends radially beyond said clevis.

9. A jaw assembly according to claim 7, wherein:

said distal portions of said jaws define a first outer diameter, said ridge defines a second outer diameter, and said proximal portion of said second jaw defines a tang hole, wherein a distance between said pivot axis and said tang hole is greater than structurally possible if said ridge was of said first outer diameter.

10. A jaw assembly according to claim 7, wherein:

said distal portions of said jaws define a first outer diameter, and said ridge defines a second outer diameter at least five percent larger than said-first outer diameter.

11. A jaw assembly according to claim 10, wherein:

said distal portions of said jaws define a first outer diameter, and said ridge defines a second outer diameter less than fifteen percent larger than said first outer diameter.

12. A jaw assembly according to claim 10, wherein:

said second outer diameter is approximately 3.5 mm.

13. A jaw assembly, comprising:

a) a tubular member having proximal and distal ends;
b) jaw assembly coupled to-said distal end, said jaw assembly including i) a clevis having proximal and distal portions, said distal portion defining a pivot axis, ii) a first jaw coupled to said clevis, and iii) a second jaw having a proximal tang and being rotatably coupled to said clevis about said pivot axis, wherein said first and second jaws define a first outer diameter of said jaw assembly, and said second jaw defines a second outer diameter at a location through which said pivot axis extends larger than said first outer diameter; and c) actuation means for moving said second jaw relative to said first jaw.

14. An endoscopic surgical device, comprising:

a) a tubular member having proximal and distal ends;

b) jaw assembly coupled to said distal end, said jaw assembly including i) a clevis having proximal and distal portions, ii) a first jaw having proximal and distal portions, and iii) a second jaw having proximal.and distal portions, said proximal portion of said second jaw defining a pivot axis about which said second jaw is rotatable relative to said first jaw on said clevis, wherein said proximal portions of said first and second jaws define a circumferential ridge about said jaw assembly extending radially beyond said distal portions of said first and second jaws; and c) actuation means for moving said second jaw relative to said first jaw.

15. An endoscopic assembly, comprising:

a) an endoscope having a working channel with a first diameter; and b) an endoscopic instrument extending at least partially within said working channel, said endoscopic instrument including a distal end effector assembly provided with a ridge about its circumference thereby defining ridged and non-ridged portions of said end effector assembly, wherein said ridged portion approximates said first diameter and said non-ridged portion has a second diameter less than said first diameter.

16. An endoscopic assembly according to claim 15, wherein:
said first diameter is approximately 3.5 mm.

17. An endoscopic assembly according to claim 15, wherein:
said distal end effector assembly is a jaw assembly.

18. An endoscopic assembly according to claim 15, wherein:

said first diameter is at least five percent greater than said second diameter.

19. An endoscopic assembly according to claim 15, wherein:
said first diameter is between five and fifteen percent greater than said second diameter.

20. The jaw assembly of any one of claims 1-13, wherein the second outer diameter is coaxial with the pivot axis.