US20050125010A1 - Flexible surgical clip applier - Google Patents

Abstract

A flexible clip applier includes a flat wire wound tubular coil, a pair of jaws at the end of the coil, end effector wires extending through the coil and coupled to the jaws, and a clip-advancing wire extending through the coil. A clip chamber is defined in the distal end of the coil. A clip pusher is provided at a distal end of the clip-advancing wire, and advances a clip into the jaws when the clip-advancing wire is moved distally. The jaws include channels in which a distalmost clip rides when the jaws are closed and the pusher is advanced, thereby causing the distalmost clip to be pushed over the tissue, and a distal anvil which operate to bend a portion of the clip to facilitate its retention on the clamped tissue. The device can push a clip with a force in excess of 1500 grams.

Description

• This application is a continuation-in-part of U.S. Ser. No. 09/891,775, filed Jun. 25, 2001, which is hereby incorporated by reference herein in its entirety.
BACKGROUND OF THE INVENTION
• 1. Field of the Invention
• This invention relates broadly to surgical devices. In particular, this invention relates to a surgical clip applier which is adapted for use through an endoscope and may be used to clamp and/or suture, ducts, vessels, and other tissues, to anchor a tissue, or to attach a foreign body to a tissue. In addition, this invention relates to a flexible surgical device adapted to provide a relatively large pushing force at the distal end of the device relative to an outer tubular element of the device. For purposes of the invention, “pushing force” is defined as a force transmitted from a proximal handle to a distal end of a flexible advancing element extending through the outer tubular element which imparts compression to the advancing element and tension to the outer tubular element.
• 2. State of the Art
• Surgical clips are generally used to apply clamping force to ducts, vessels, and other tissues. In addition, surgical clips are particularly useful in controlling bleeding of a tissue in lieu of suturing or stapling where suturing or stapling is difficult.
• All of the currently available surgical multifiring clip appliers are substantially rigid devices intended to extend through a trocar port or through an incision to a surgical site requiring application of a clip. The devices have been rigid because a stiff pushing element has been required in order to exert the required pushing force to move the clip over the tissue.
• However, there is a substantial need for a flexible clip applier, particularly one insertable through a lumen of an endoscope. The ability to apply clips through an endoscope would permit myriad minimally invasive surgical solutions to medical problems, especially those of the gastrointestinal tract. However, it is accepted theory that the transmitted force required to advance or form a clip over tissue cannot be produced in the distalmost end of a long flexible device that is commonly constructed with a metal tubular coil, or polymer tube, such as an endoscopic device or catheter. For example, C. Paul Swain, Md., a recognized expert in endoscopic instruments and particularly endoscopic stapling devices, has stated that “[i]t is hard to exert more than 200 g of force on the tissue when pushing . . . This fact is of course one feature that makes intervention at flexible endoscopy relatively safe”. See C. Paul Swain, “What Endoscopic Accessories Do We Really Need?”, Emerging Technologies in Gastrointestinal Endoscopy,Gastrointest. Endosc., Vol. 7, No. 2, pp. 313-330 (April 1997). Yet, a pushing force substantially greater than 200 g is required to push a clip over compressed tissue. In fact, it is believed a force in excess of 500 grams (1.1 lbs) is required for a satisfactory instrument, and substantially greater forces, e.g., in excess of 1500 grams (3.3 lbs) would be desirable.
• Generally a flexible endoscopic device (e.g., a biopsy forceps device) includes an outer tubular member, typically being constructed of a metal tubular coil or a polymer tube which is poor in transmitting forces that impart tensile stresses to the outer sheath, a control element longitudinally movable relative to the tubular member, an end effector coupled to the distal ends of both the tubular member and the control element such that relative movement of the control element and the tubular member causes operation of the end effector, and a handle which moves the control element relative to the handle. This type of flexible endoscopic instrument is limited in the amount of pushing force it can generate for several reasons. Compression of a flexible control element (pushing element) tends to cause the pushing element to buckle within the outer flexible sheath of the device. If a relatively larger diameter flexible pushing element is used such that it better resists buckling, the pushing element may impart too much stiffness to the flexing of the endoscopic instrument. In addition, a flexible pushing element of larger diameter is subject to greater frictional forces within the outer sheath which reduces the force transmitted from the handle to the end effector. If the flexible pushing element is made relatively smaller in diameter, it is subject to kinking which will result in little to no force transmitted to the distal end. Kinking is especially a problem in endoscopic instruments, as the endoscope and its lumen may be extended through a tortuous path. For these reasons and others, mechanical application of a relatively large distal end pushing force and particularly clip application have been absent from the capability of flexible endoscopic tools.
SUMMARY OF THE INVENTION
• It is therefore an object of the invention to provide a flexible endoscopic device capable of generating a relatively large pushing force at its distal end.
• It is another object of the invention to provide an endoscopic clip applier.
• It is a further object of the invention to provide a flexible clip applier which can exert a pushing force of at least 500 grams (1.1 lbs), and preferably in excess of 1500 grams (3.3 lbs) via a manually actuatable handle.
• It is an additional object of the invention to provide a surgical clip applier which is adapted for use in minimally invasive surgery.
• It is also an object of the invention to provide a surgical clip applier which has a pushing element which is not subject to kinking.
• It is yet another object of the invention to provide a surgical clip applier which has a pushing element which does not create unsuitably high frictional forces within the outer sheath.
• It is still a further object of the invention to provide a surgical clip applier which can store and apply multiple clips.
• In accord with these objects, which will be discussed in detail below, a surgical clip applier is provided having a flexible, preferably flat wire wound outer tubular coil, a pair of jaws at the distal end of the tubular coil, a set of end effector wires extending through the outer tubular coil and coupled to the jaws, and a clip-advancing wire extending through the tubular coil. A lubricious, preferably extruded polymer, multilumen barrier sheath extends within the tubular coil and separates the wires from each other and the tubular coil. A clip chamber is provided in the distal end of the tubular coil and stores a plurality of linearly arranged clips. A clip pusher is provided at a distal end of the clip-advancing wire, and adapted to advance the clips in the chamber toward the jaws when the clip-advancing wire is advanced through the barrier sheath and outer tubular coil. The jaws include clamping surfaces which operate to compress tissue between the jaws when the jaws are closed, guides in which a distalmost clip rides distally and is advanced over the clamped tissue when the line of clips is advanced by the clip pusher, and a distal anvil which operates to bend a portion of the distalmost clip to enhance its retention on the clamped tissue. A proximal handle is provided for movement of the clip-advancing wire and end effector wires relative to the barrier sheath to effect (1) clamping and rotation of the jaws (relative to each other and about the longitudinal axis of the tubular coil), and (2) advancement of the clip-advancing wire to effect distal movement of a clip.
• The flat wire wound tubular coil is preferred over round wire (though not necessarily required over a round wire wound tubular coil) because it is flexible, yet sufficiently longitudinally stiff such that the device may be pushed through the lumen of the endoscope. In addition, the flat wire wound tubular coil can be made with a high preload and has a tensile spring constant sufficiently high that it resists buckling and uncoiling during application of a pushing force by the handle against the clip-advancing wire. The clip-advancing wire has a sufficiently large diameter to transmit force, yet small enough to minimize internal friction when moved within a device flexed through a tortuous path in an endoscope. The end effector wires are large enough to handle the high closing force from the handle, and to resist compressive buckling when moved in an opposite direction, yet small enough to be coupled to diminutive jaws. The multilumen barrier sheath supports the clip-advancing wire and end effector wires along their length to reduce compressive buckling, and provides a separation layer to reduce friction. Movement of the clip-advancing wire relative to the outer tubular coil causes a compressive force in the clip-advancing wire and tensile forces in the outer tubular member such that a relative pushing force is transmitted to the distal end of the clip-advancing wire in excess of the perceived threshold of the 200 grams (0.44 lbs). In fact, one embodiment of the device of the invention, sized for endoscopic use, provides a pushing force in excess of 2267 grams (5 lbs).
• In operation, the jaws can be moved through a working channel of an endoscope in a closed position. Once exited, the handle can be operated to open the jaws and rotate the jaws to a desired orientation. The jaws are positioned on either side of tissue about which it is desired to place a clip and the handle is operated to pull the end effector wires such that the jaws clamp about the tissue. The handle is then locked to maintain the jaws in the clamped position. The handle is operated to effect advancement of the clip-advancing wire through the tubular coil such that a clip is advanced through the jaw guides and over the tissue. The clip is advanced until a portion thereof is forced against the anvil of the jaws to effect bending of the clip portion such that that portion moves laterally to pierce the clamped tissue. After the clip is applied, the jaws are released from about the tissue, and the end effector assembly may then be moved to another tissue location to apply additional clips.
• Additional objects and advantages of the invention will become apparent to those skilled in the art upon reference to the detailed description taken in conjunction with the provided figures.
BRIEF DESCRIPTION OF THE DRAWINGS
• FIG. 1 is a partial section side elevation view of a surgical clip applier according to the invention, shown with the handle configured to provide the jaws in an open configuration;
• FIG. 2 is a broken perspective view of a distal portion of the clip applier according to the invention;
• FIG. 2A is an exploded and broken perspective view of a distal portion of the clip applier according to the invention;
• FIG. 2B is a broken schematic view of a distal end of the clip-advancing wire and the coil connector;
• FIG. 2C is a broken schematic view of a distal end of the clip-advancing wire and the coil connector illustrating the limitation on proximal movement of the clip-advancing wire relative to the coil connector;
• FIG. 3 is a perspective view of the jaw assembly of the clip applier according to the invention, and a clip;
• FIG. 4 is a partial section side elevation view of a surgical clip applier according to the invention, showing the right side of the handle positioned to place the jaws in an unloaded closed configuration;
• FIG. 4A is a view similar toFIG. 4, illustrating alternative embodiments to the handle of the clip applier according to the invention;
• FIG. 5 is an enlarged view of the handle of the surgical clip applier with the handle in the same position as shown inFIG. 4;
• FIG. 6 is a view similar toFIG. 4 of the left side of the handle;
• FIG. 7 is a view similar toFIG. 6 with the addition of the various springs;
• FIG. 8 is an enlarged broken section view of the proximal left side of the handle of the clip applier according to the invention;
• FIG. 9 is an enlarged side perspective view of the end effector assembly;
• FIG. 10 is an enlarged distal end perspective view of the end effector assembly;
• FIG. 11 is a broken partial section side elevation view of the distal end of the clip applier according to the invention;
• FIG. 12 is a view similar toFIG. 1, showing the handle configured such that the jaws are in a unloaded closed position, and shown without the pinion on the jaw closing lever;
• FIG. 13 is a partial section perspective view of a surgical clip applier according to the invention, illustrating rotation of the end effector assembly by operation of the rotation knob;
• FIG. 14 is a partial section side elevation view of a surgical clip applier according to the invention, showing the jaws in a clamped configuration;
• FIG. 15 is a partial section side elevation view of a surgical clip applier according to the invention, showing the jaws in a clamped configuration and the clip-advancing lever actuated;
• FIG. 16 is an enlarged partial section view of the handle of the surgical clip applier, showing the clip-advancing lever actuated;
• FIG. 17 is a longitudinal section view of the distal end of the clip applier according to the invention, shown with the jaws in a closed configuration and a formed clip therebetween;
• FIG. 18 is a broken partial section side elevation view of the distal end of the clip applier according to the invention, shown with the jaws in an open configuration and a formed clip therebetween;
• FIG. 19 is a broken partial section side elevation view of the distal end of the clip applier according to the invention, shown with the jaws in an open configuration, the formed clip released, and the retainer of a subsequent clip protruding between the jaws;
• FIG. 20 is a longitudinal section view of the distal end of the clip applier according to the invention, shown with the jaws in an open configuration and the retainer retracted relative to the view ofFIG. 19;
• FIG. 21 is a partial section side elevation view of a surgical clip applier according to the invention, shown with the jaws in an open position and a formed clip released therefrom;
• FIG. 22 is a table listing dimensions for the tubular coil, clip-advancing wire, and end effector wires of six prototypes, and the resultant output force achieved with the prototype; and
• FIG. 23 is an efficiency plot of the prototypes described in the table ofFIG. 22.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
• Turning now toFIGS. 1, 2,2A and3, aflexible clip applier10 suitable for insertion through a working channel (lumen) of an endoscope is shown. Theclip applier10 generally includes a flexible, flat wire wound outertubular coil12 having anend effector assembly13 mounted at adistal end16 thereof. Theend effector assembly13 includes a clevis (jaw mount)14 rotatably supporting a pair ofjaws18,20.End effector wires22,24 extend through thetubular coil12 and havedistal ends26 respectively coupled to thejaws18,20. A clip-advancingwire30 extends through thetubular coil12 and includes adistal end32 provided with aclip pusher34. A lubricious, preferably extruded,multilumen barrier sheath36 extends through substantially the entire length of the outertubular coil12 and separates theend effector wires22,24 and clip-advancingwire30 from each other and the outertubular coil12. Aproximal handle assembly40 is provided for moving theend effector wires22,24 and clip-advancingwire30 relative to thetubular coil12 to effect clamping and rotation of the jaws and advancement of a clip, as described in detail below.
• Referring toFIGS. 4 and 5, more particularly, thehandle assembly40 includes a housing defined by twoshell portions42,44, astationary handle46, ajaw closing lever48 linearly movable within aslot50 in the housing and relative to thestationary handle46, and a clip-advancinglever52 rotatably mounted on thejaw closing lever48 with apivot pin54. Thejaw closing lever48 is coupled to theend effector wires22,24, as described in detail below. Thejaw closing lever48 is biased into an open position (away from the stationary handle46) with aconstant force spring56 held in a distal portion of the housing such that thejaws18,20 are in an open configuration when no manual force is applied against the force of thespring56 to move the jaw closing lever toward the stationary handle. The clip-advancinglever52 is forced into an open position, also away from thestationary handle46, with a torsion spring58 (FIGS. 4 and 7). The clip-advancinglever52 is coupled to the clip-advancingwire30, as discussed in detail below, with rotation of the clip-advancinglever52 operating to move theclip pusher34 at thedistal end32 of the clip-advancingwire30 longitudinally within the tubular coil.
• Atube60 extends from the interior of thehandle40 to the exterior and includes aproximal rotation knob62. The proximal end of the clip-advancingwire30 is clamped, or otherwise held, within thetube60 such that rotation of theknob62 causes rotation of the entire clip-advancing wire. Adistal end64 of thetube60 is rotatably coupled within acollar66. Thecollar66 is fixedly coupled to arack68. Linear movement of therack68 within the housing causes the tube to move longitudinally within and outside the housing.
• Alternatively, referring toFIG. 4A, thetube60 may be telescoping, having two rotationally interferingsections60aand60b, such that movement of therack68 moves adistal section60aof the tube relative to aproximal section60b, thereby maintaining a constant length for extension of theproximal section60bof the tube outside the housing. The rotationally interfering portions, e.g., each having a hex shape, permit rotationally forces to be transmitted from theknob62 to thedistal end64 of the tube.
• Referring back toFIG. 4, apinion70 is rotatably mounted at72 to anupper portion74 of the clip-advancinglever52 and positioned to act on therack68 when the clip-advancing lever is rotated. As such, when the clip-advancinglever52 is rotated aboutpivot54 toward thejaw closing lever48, therack68 and the clip-advancingwire30 are advanced. Therack68 is preferably substantially longer than what is required by the number of teeth on thepinion70. As a result, thepinion70 can act upon therack68 in any location at which thejaw closing lever48 may be positioned upon closing thejaws18,20. This, when thejaw closing lever48 is pulled back toward thestationary handle46 to effect closure of thejaws18,20 about tissue, thejaw closing lever48 may be located at a location which is consistent with the thickness and consistency of the tissue about which the jaws are to be closed.
• The teeth of thepinion70 are preferably at a positive engagement angle relative to the teeth of therack68 because of the location of thepinion pivot axis72. Then, when the pinion is rotated, the rack is moved longitudinally. Aleaf spring76 acts between thepinion70, athole78, and the advancinglever52 atshelf77 to force thepinion70 into therack68. After firing a clip, as discussed below, release of the clip-advancinglever52 allows thespring58 to return thelever52 back to its unbiased position, and thepinion70 rotates about thepinion axis72 against theleaf spring76 and over therack68.
• Turning now toFIGS. 6 through 8, thejaw closing lever48 includes a spring activatedcatch system80 which locks the jaw closing lever when a predetermined load is applied thereto rather than when the closing lever is located at any particular location. Thecatch system80 includes the following structures on anupper mount portion82 of the jaw closing lever48: aproximal spring mount84; two spaced apartbolts86,88; and a lockingtooth90. The lockingtooth90 includes a proximal cam92. Thecatch system80 further includes the following additional structures: alatch94 having alinear slot96 and acam slot98, which are positioned overbolts86,88 respectively; an endeffector wire mount100 to which the proximal ends of theend effector wires22,24 are attached; anupper cam surface102 for the below-describedlever lock110; and aspring catch104. An extension spring106 (FIG. 7) is held between thespring mount84 andspring catch104. A generally L-shapedlever lock110 is rotatably coupled about alever pivot114 formed at the proximal end of the handle. Anelongate portion116 of thelock110 includes a comb; i.e., theportion116 includes a plurality ofteeth118, each of which include a distal camming surface120. Anotherportion122 of thelever lock110 is provided with arelease button124 which extends outside of the handle housing. Atorsion spring130 is provided about thepivot114 to bias thelever lock110 down toward the lockingtooth90. Asafety132 is also provided to prevent release of thejaw closing lever48 when the clip-advancinglever52 is moved from an unbiased position, thereby preventing inadvertent release of unapplied clips.
• Once the jaws are closed about tissue, as discussed further below, it is desired to maintain their closed position until a clip is advanced over the tissue. In view of this object, thecatch system80 function as follows. Still referring toFIGS. 6 through 8, thecam surface102 is generally adapted to position theteeth118 of thelever lock110 located in front of the lockingtooth90 above the locking tooth, such that thejaw closing lever48 may be moved linearly. When thejaw closing lever48 is moved toward thestationary lever46, tension is increased in theend effector wires22,24 to move thejaws18,20 from an open position to a closed position. As the tension increases in theend effector wires22,24 and exceeds the tension of theextension spring106, thelatch94 moves distally relative to thejaw closing lever48. Then, movement of thejaw closing lever48 relative to thelatch94 causes thebolts86,88 to ride within thelinear slot96 and thecamming slot98, respectively. Referring toFIG. 8, movement ofbolt88 withincamming slot98 forces the proximal end of thelatch94 downward and permits thelever lock110 to rotate clockwise. This causes the lockingtooth90 to engage thetoothed portion116 of thelever lock110 and lock the position of thejaw closing lever48. The load applied to the end effector wires is then limited to the force applied by the extension spring106 (FIG. 7). Thejaw closing lever48 then may be released by pushing therelease button124 sufficiently to rotate thelever lock110 against the bias of thetorsion spring130 and clear the lockingtooth90.
• Turning now toFIGS. 1, 2,4 and6, the distal end of thehousing42,44 of thehandle assembly40 includes aslot131 in which two preferably substantially rigid and preferablylow friction tubes133,135, e.g., brass tubes, are provided. Theproximal end136 of thetubular coil12 is coupled to the housing in alignment with thetubes133,135 with aflare nut coupling138 or an equivalent assembly. The clip-advancingwire30 extends from therotation tube60 throughtube133 and into a clip-advancingwire lumen140 of thebarrier sheath36. The clip-advancingwire30 extends therethrough to thedistal end16 of thetubular coil12. Theend effector wires22,24 extend from endeffector wire mount100 throughtube135 and into respective endeffector wire lumina142,144 of thebarrier sheath36, and then extend therethrough to the distal end of the tubular coil.Wires22,24 and30 are provided in separate lumina within thebarrier sheath36 in order to minimize friction between the wires and reduce buckling and kinking of the wires along the length of thetubular coil12.
• Turning again toFIG. 4A, rather than using tubes to direct the wires from the housing into the barrier sheath in tubular coil, the housing may be formed with channels which provide the same function. For example,channels132a,132bare adapted to direct the clip-advancingwire30 andend effector wires22,24, respectively, into thebarrier sheath36 within thetubular coil12. In addition, the housing may be formed with distal structure, e.g., acylindrical protrusion146, facilitating the coupling of a flare nut assembly thereto.
• Referring back toFIG. 2, thetubular coil12 is a preferably stainless steel (or other metal or metal alloy) flat wire wound wire tubular coil, though a round wire wound tubular coil may be used. Thetubular coil12 is fairly stiff such that the device can be pushed through the endoscope to the treatment area. Thetubular coil12 has a spring constant sufficiently high in order to resist uncoiling when subject to the tensile load created when the handle applies a pushing force to the clip-advancing wire and the clips, as discussed in more detail below, and minimize buckling during force transmission. In addition, thetubular coil12 is preloaded such that each turn is substantially in contact with the adjacent turns 360° around the tubular coil. The outer diameter of thetubular coil12 has an outer diameter smaller than the inner diameter of the working channel (lumen) of an endoscope for which it is intended, and the inner diameter of the tubular coil should be maximized so that it may readily accept the barrier sheath, and clip-advancing wire and end effector wires, as well as form a chamber for a plurality of clips, as discussed below. In preferred embodiments, thetubular coil12 of a device adapted for an endoscope having a 3.2 mm working channel has an outer diameter preferably not exceeding approximately 3.175 mm (0.125 inch), and a preferably an inner diameter of at least approximately 0.90 mm (0.035 inch) so that it may accept theend effector wires22,24, clip-advancingwire30,barrier sheath36, and clips202. The tubular coil inner diameter preferably corresponds to the transverse dimension of aclip202, discussed below, so that the clip is stably directed through thechamber200. The wire of thetubular coil12 has a width W preferably between approximately 0.635 mm to 1.270 mm (0.025 inch to 0.050 inch), and a thickness T preferably at least approximately 0.13 mm to 0.75 mm (0.005 inch to 0.030 inch). The tubular coil length should at least be the length of the endoscope working channel, generally 150 cm to 250 cm. A substantial length of thetubular coil12 is preferably covered in a high density polyethylene (HDPE) sheath150 (FIGS. 1, 2 and2A).
• Thebarrier sheath36 within the tubular coil is preferably non-circular in shape to reduce contact points and thereby minimize friction between the barrier sheath and the tubular coil. The primary purpose of the sheath is to maintain a close fitting bearing surface for the clip-advancing wire, although its three distinct lumina help reduce friction between all the wires. Thesheath36 preferably free floats within the tubular coil; i.e., it is not attached to the tubular coil at its ends or along its length. Preferred cross-sectional shapes include generally rectangular and triangular (each with or without broken or rounded edges) and trefoil. Thebarrier sheath36 is preferably an extrusion made from polypropylene, an FEP fluoropolymer resin (FEP), polytetrafluoroethylene (PTFE), high density polyethylene (HDPE), nitrol polyvinyl chloride, nylon, or any other lubricious polymer.
• The clip-advancingwire30 is preferably made of nickel-titanium alloy (NiTi) or stainless steel. The NiTi construction permits the clip-advancingwire30 to transmit torque (by rotation of the rotation knob62) without taking a cast, and with minimal whipping. The clip-advancingwire30 has a sufficiently large diameter to transmit force, yet not so large that it is prevented from functioning through a tortuous path or fit within thetubular coil12. A preferred diameter for the clip-advancing wire is approximately 0.375 mm to 0.89 mm (0.015 inch to 0.035 inch).
• Referring toFIGS. 2, 2A and2B, thedistal end32 of the clip-advancingwire30 has a non-circular cross-section, and is preferably rectangular in shape. Thedistal end32 is preferably a length four to five times the length of theclip pusher34. Acoil connector152 is coupled within thedistal portion16 of thetubular coil12, e.g., by welding, press fitting, interference fit, pinning, etc., preferably approximately 25 mm to 50 mm from the distal end of the tubular coil (i.e., the length of a linear arrangement of five or so clips), and includes acentral keyhole156 having a non-circular cross section, and two end effector channels158 (only one shown) through which theend effector wires22,24 extend. Thedistal end32 of the clip-advancingwire30 can be longitudinally moved through thekeyhole156, with thetransition159 of the clip-advancingwire30 from non-circular to circular outer shape functioning as a stop against thekeyhole156 for additional distal movement.
• Referring toFIG. 2B, thedistal end32 of the clip-advancingwire30 also includesnotches250 along oneside251 of thedistal end32 which have adistal surface252 substantially perpendicular to theside251 and proximalbeveled surface254. Thecoil connector152 includes aresilient catch256 in alignment with thenotches250. When the clip-advancingwire30 is moved distally through thekeyhole156, thebeveled surface254 of thenotches250 rides against thecatch256, bending the catch for clearance. However, asdistal surface252 interferes with thecatch256 when the clip-advancingwire30 is moved proximally relative to thecoil connector152, the clip-advancingwire30 may not be moved proximally by a distance which would cause anotch250 to pass the catch256 (FIG. 2C).
• Moreover, rotation of the clip-advancingwire30 causes a rotational moment to be applied to theconnector152 and consequently the distal end of thetubular coil12. The distal end of the preloadedtubular coil12 can be thereby rotated 360° in each of the clockwise and counterclockwise directions by rotation of therotation knob62 attached to the proximal end of the clip-advancingwire30. Because theend effector assembly13 is attached to the distal end of the tubular coil, rotation ofknob62 effects rotation of theend effector assembly13 and thejaws18,20.
• Theend effector wires22,24 are large enough in diameter to preferably handle up to fifteen pounds of closing force from the handle assembly and also to handle the force required to open thejaws18,20 without buckling. However, the end effector wires must be small enough in diameter to attach to the jaws, and fit in thetubular coil12. A preferred diameter for the end effector wires is approximately 0.178 mm to 0.375 mm (0.007 inch to 0.015 inch), though other sizes may be used.
• Referring toFIGS. 9 and 10, theclevis14 of theend effector assembly13 is preferably coupled directly to the distal end of thetubular coil12. Theclevis14 includes acentral clip channel164 having a preferably rectangular cross section, and twolateral openings165 through which the distal ends of theend effector wires26,28 can respectively exit. Thejaws18,20 are each rotatably coupled about theclevis14 with a respective axle166 (one shown) which does not interfere with thechannel164. Eachjaw18,20 includes aproximal tang168,169 respectively, which is coupled to the distal ends of the respectiveend effector wires26,28. The distal portion of eachjaw18,20 includes aclip guide170,172, respectively, and clampingsurfaces174,176 onjaw18, and clampingsurfaces178,180 onjaw20 extending along each side of theguide172. All of the clamping surfaces174,176,178,180 preferably have proximally directedteeth182 which pulls target tissue toward theclip channel164 as the jaws are closed, and also securely grips the tissue when a clip is advanced thereover. The distal end ofjaw18 includes ananvil184 which is in alignment with theclip guide170 which curves (or is angled) towardjaw20.Jaw20 includes two distal anvil guides186,188 between which theanvil184 is positioned when the jaws are moved to a closed position.Jaw20 also defines adistal well190 between the anvil guides186,188 which is lower than the surface ofclip guide172.
• Referring toFIG. 11, aclip chamber200 for storing a plurality of linearly arranged clips202 (FIG. 2A), described further below, is formed between the coil connector152 (FIGS. 2 and 2A) and thedistal end16 of thetubular coil12. Theclip chamber200 extends into theclip channel164 of theclevis14. Theclip pusher34 is provided at the proximal end of the chamber and situated to push on a proximalmost clip such that all clips in front of theclip pusher34 are advanced toward thejaws18,20 when the clip-advancinglever52 is actuated to cause the clip-advancingwire30 to move distally relative to thetubular coil12.
• Theclip pusher34, preferably made of stainless steel, is coupled to thedistal end32 of the clip-advancingwire30, e.g., by mechanical joining or welding. Theclip pusher34, as described in more detail below, is provided with a shape substantially similar to the distal portion of a clip202 (FIG. 2A) adapted to be used in the clip applier.Such clips202 are described in detail in previously incorporated U.S. Ser. No. 09/891,775. Generally, referring toFIG. 2A, theclips202 are each in a generally U-shaped configuration with first andsecond arms204,206, and abridge portion208 therebetween. Thefirst arm204 extends into adeformable retainer214 preferably having a tissue-piercing end216 and preferably also ahook218, and thesecond arm206 is provided with atip210 preferably having one or more catches212. Theclip202 is provided with structure that facilitates the stacking (or chaining) of a plurality of clips in theclip chamber200. The structure includes: anotch220 at a junction of thesecond arm206 and thebridge portion208 which is adapted to receive thetip210 of thesecond arm206 of another clip; anelongate recess222 along the exterior of thefirst arm204 which is adapted to receive theretainer214 of the first arm of another clip; and aninterior configuration224 at the ends of the first and second arms which corresponds to an exterior shape of theproximal bridge portion208 of another clip. In one embodiment, theclips202 are each approximately 6.86 mm (0.27 inch) in length from thebridge208 to the end of theretainer214, have a width of approximately 0.90 mm (0.035 inch), and a height of 1.80 mm (0.070 inch). However, it is understood that the clip dimensions may be adapted for use in devices having tubular coil inner diameters of various sizes.
• Referring toFIGS. 2 and 2A, theclip pusher34 includes arear clip seat228 which corresponds to the exterior shape of the proximal end of the clip. Theclip pusher34 also includes adistally extending arm230 having a distal clip catch232 (adapted to seat in therecess222 of clip202), and ashoulder234 adjacent theclip seat228 on the side opposite thearm230. As such, theclip pusher34 includes structure which is adapted to conform the proximal end of aclip202 for transferring a pushing force relative to the tubular coil. In addition, theclip catch232, by engaging in therecess222 of aclip202, prevents clips from unintentionally moving distally. The clip catch also permits moving aclip202 proximally, by retracting theclip pusher34 such that theclip catch232 forces back against wall at the rear of therecess222 and pulls the engaged clip proximally, which in turn moves other clips in the ‘chain’. The operation of the distal portion of the device10 (including theend effector assembly13, theclip pusher34, and the clip chamber200) will become evident with reference to the following description of the use of thedevice10.
• Referring toFIGS. 4 and 12, thejaw closing lever48 is moved toward thestationary handle46, against the bias ofspring56, to cause thejaws18,20 of theend effector13 to move into a closed position. Movement of thelever48 adapts, in size, the distal end of the device for delivery through the lumen (working channel) of an endoscope, but preferably does not substantially load theend effector wires22,24. Once theend effector assembly13 has exited the distal end of the endoscope, thejaw closing lever48 can be released to open the jaws (FIG. 1). Referring now toFIG. 13, theproximal rotation knob62 can be rotated which, as discussed above, effects rotation of the entire clip-advancingwire30 and, hence, rotation of theend effector assembly13. Briefly, this is because theend effector assembly13 is coupled to thetubular coil12 and the tubular coil is provided with a fixedcoil connector152 which is rotated by rotation of thedistal end32 of the clip-advancingwire30.
• Turning now toFIG. 14, once thejaws18,20 of theend effector assembly13 are positioned on either side of tissue (not shown) about which it is desired to place a clip202 (FIGS. 2 and 2A), thejaw closing lever48 is again moved toward thestationary handle46 to clamp the jaws about the tissue. Thelever48 is moved relatively further than shown inFIG. 12, as thewires22,24 will be under load to compress the tissue. Referring back toFIGS. 9 and 10, theteeth182 on the clamping surfaces174,176,178,180 of thejaws18,20 are angled proximally to pull the tissue into the jaws assembly and securely hold the tissue against the distally directed force of an advanced clip. As the jaws close, theanvil184 moves between the anvil guides186,188, and may partially or fully pierce the tissue.
• Once the jaws are fully clamped about the tissue, the lockingtooth90 engages with thelever lock110 as thelatch94 moves down to allow engagement and thereby lock thejaw closing lever48 relative to thestationary handle46, as discussed above with respect toFIGS. 6 and 7. As discussed above, the jaws are locked based upon the load in the handle, rather than at any particular position. This permits locking the jaws about tissues of various thicknesses and compressive properties. Moreover, it is noted that when thejaws18,20 are fully clamped, theend effector wires22,24 are placed under tension which provides compression to thetubular coil12 such that the coil has an effectively higher tensile limitation before stretching.
• Referring now toFIGS. 15 and 16, after the jaws are clamped about the tissue, the clip-advancinglever52 is rotated about thepivot pin54 to effect advancement of the clip-advancingwire30 through thetubular coil12. More particularly, aslever52 is rotated toward thejaw closing lever48, thepinion70 engages therack68 to move the rack relatively distally. As the proximal end of the clip-advancingwire30 is longitudinally fixed relative to therack68, thedistal end32 of the clip-advancingwire30 is consequently moved distally. Referring toFIGS. 10 and 17, thepusher34, at thedistal end32 of the clip-advancingwire30 distally advances theclips202a,202b,202c,202din thechamber200, and particularly forces thedistalmost clip202athrough thechannel164 in theclevis14 and between thejaws18,20. Asclip202ais further advanced, the first andsecond arms204,206 ride inguides170,172, respectively, and are forced over the tissue held between thejaws18,20. When the retainer2.14 on thefirst arm204 of theclip202ais forced against theanvil184, theretainer214 is bent towardjaw20; the tip216 pierces the tissue between thejaws18,20 (or is guided into the pierce hole made by theanvil184 when the jaws clamped the tissue); and the tip216 enters the well190 at the distal end ofjaw20 to extends around thetip210 of thesecond arm206 which overhangs the well. Thehook218 at the tip216 of theretainer214 may engage (although it does not necessarily engage), thelatch212 at the distal end of thesecond arm206. The force provided by the clip-advancingwire30 to advance aclip202 over the clamped tissue, to bend theretainer214 against theanvil184, and to force the tip216 of the retainer to pierce tissue is at least 500 grams (1.1 lbs), and more typically approaches 1500 grams (3.3 lbs) or higher.
• Referring now toFIGS. 6 and 18, after the clip is applied, thejaws18,20 are released from about the tissue. This is done by pressing therelease button124 of thelever lock110 such that thejaw closing lever48 is permitted to move relative to thestationary handle46.
• Referring toFIG. 19, the clip is then released from the end effector jaw assembly by moving the jaw assembly relative to the appliedclip202a. The end effector assembly may then be moved to another tissue location to apply additional clips.
• It is noted that afterclip202ais released, theretainer214bofclip202bpartially extends into the space between thejaws18,20. If not retracted, thisretainer214bwould obstruct positioning thejaws18,20 about the tissue and subsequent clip application during the procedure. However, when the clip-advancinglever52 is released, torsion spring58 (FIG. 4) operates to pull back the clip-advancingwire30 and theclip pusher34 and thereby retract the ‘chain’ of clips. That is, theclip catch232 of the clip pusher pulls back onclip202d, and the retainer214dofclip202dpulls backclip202c, and so on, until the extendingretainer214bis pulled within thechamber164 of the clevis, and the space between thejaws18,20 is cleared, as shown inFIGS. 20 and 21. The clip-advancing wire is limited in the distance by which it can be retracted; it may be retracted only so far as permitted by interference of aridge250 on the clip-advancingwire30 located just distal thecatch256 of thecoil connector152, and the catch256 (FIG. 2B), which is constructed to be approximately the length of the protrudingretainer214b.
• The device may then be used to apply another clip, or the jaws may be closed and the device may be withdrawn through the endoscope.
• The resulting clip applier is capable of transmitting a pushing force at the distal end of the clip-advancing wire, resulting from the compressive force appliable to the clip-advancing wire and the relative tensile force appliable to the outer tubular coil and end effector wires, far in excess of the perceived threshold of the 200 grams (0.44 lbs) in the prior art. In fact, as discussed below, one embodiment of the device of the invention provides a pushing force in excess of 2267 grams (5 lbs).
• More particularly, referring toFIG. 22, a table listing part dimensions of six prototype device, and the resultant output forces achieved with prototype devices is provided.FIG. 23 provides an efficiency plot (input pushing force v. output pushing force) for the use of the prototypes. In all prototypes, the tubular coil, clip-advancing wire, and end effector wires are made from stainless steel. Details of the table and the efficiency plot are discussed below with respect to Examples 1 through 6.
EXAMPLE 1
• In a first prototype, indicated by ‘RUN #1’, ‘RUN #2’ and ‘RUN #3’, thetubular coil12 has an outer diameter of 0.09 inch and an inner diameter of 0.06 inch. The clip-advancingwire30 has an outer diameter of 0.017 inch and theend effector wires22,24 each have an outer diameter of 0.011 inch. The proximal end of theend effector wires22,24 are pulled with 11 lbs of force which generally results in 5 to 10 lbs of force at the distal end of the end effector wires, depending on the degree to which thetubular coil12 is bent (modeled by looping the tubular coil through two inch loops); i.e., frictional losses reduce the transmitted force. Moreover, it is noted that whatever force is transmitted to the distal end of theend effector wires22,24, only approximately one-fifth of that force is applied to the jaws, as the distance from thejaw tang168 to thepivot166 is relatively shorter than the length of the end of the jaw (anvil184) to thepivot166, approximately in a one to five ratio. As such, an input force of 11 lbs may results in one to two lbs of force on thejaws18,20. Applying the pulling force simulates the in-use condition in which the pushing force is transmitted.
• With thetubular coil12 extending relatively straight (i.e., through no loops) in ‘RUN #1’, an input pushing force of 8 lbs on the proximal end of the clip-advancing wire30 (i.e., a pushing force of 8 lbs on the rack68) resulted in an output pushing force of 3.82 lbs (1732.7 grams) at theclip pusher34 at thedistal end32 of the clip-advancingwire30. With thetubular coil12 extending through one two-inch loop in ‘RUN #2’, an input pushing force of 8 lbs resulted in an output pushing force of 3.42 lbs (1551.3 grams). With thetubular coil12 extending through two two-inch loops, in ‘RUN #3’, an input pushing force of 7 lbs resulted in an output pushing force of 3.37 lbs (1528.6 grams).
EXAMPLE 2
• In a second prototype, indicated by ‘RUN #4’, the diameters of thetubular coil12 andend effector wires22,24 are the same as Example 1. However, the diameter of the clip-advancingwire30 is decreased to 0.015 inch. With thetubular coil12 extending through no loops, a six pound input pushing force resulted in an output pushing force of 2.11 lbs (957 grams).
EXAMPLE 3
• In a third prototype, indicated by ‘RUN #5’, ‘RUN #6’ and ‘RUN #7’, the diameters of thetubular coil12 andend effector wires22,24 are the same as Example 1. However, the diameter of the clip-advancingwire30 is increased to 0.02 inch. With thetubular coil12 extending through no loops in ‘RUN #5’, an input pushing force of 8 lbs resulted in an output pushing force of 4.03 lbs (1828 grams). With thetubular coil12 extending through one two-inch loop in ‘RUN #6’, an input pushing force of 8 lbs resulted in an output pushing force of 4.08 lbs (1851 grams). With the tubular coil extending through two two-inch loops, in ‘RUN #7’, an input pushing force of 8 lbs resulted in an output pushing force of 3.54 lbs (1605.7 grams).
EXAMPLE 4
• In a fourth prototype, indicated by ‘RUN #8‘and ’ RUN #9’, the device includes atubular coil12 having an outer diameter of 0.086 inch and an inner diameter of 0.053 inch, a clip-advancingwire30 having a diameter of 0.017 inch, andend effector wires22,24 having diameters of 0.009 inch. With the tubular coil extending through no loops, an input pushing force of 8 lbs resulted in 4.61 lbs (2091 grams) of output pushing force. With the tubular coil extending through two two-inch loops, an input pushing force of 8 lbs resulted in 4.28 lbs (1941.3 grams) of output pushing force.
EXAMPLE 5
• In a fifth prototype, indicated by ‘RUN #10’, the clip-advancingwire30 andend effector wires22,24 of thedevice10 have the same diameters as Example 4. Thetubular coil12 has an outer diameter of 0.086 inch and an inner diameter of 0.054 inch. With thetubular coil12 extending through no loops, an input pushing force of 8 lbs resulted in 4.42 lbs (2004.9 grams) of output pushing force.
EXAMPLE 6
• In a sixth prototype, indicated by ‘RUN #111’, the clip-advancingwire30 andend effector wires22,24 of thedevice10 have the same diameters as Example 4. Thetubular coil12 has an outer diameter of 0.083 inch and an inner diameter of 0.054 inch. With thetubular coil12 extending through no loops, an input pushing force of 8 lbs resulted in 5.17 lbs (2345 grams) of output pushing force.
• Other flexible clip appliers suitable for use through a relatively smaller 2.6 mm diameter endoscope have also been constructed and tested. For example, one clip applier has atubular coil12 with an outer diameter of 0.092 inch, and an inner diameter of 0.060 inch, a clip-advancingwire30 with a diameter of 0.022 inch, andend effector wires22,24 each with a diameter of 0.013 inch. The device can apply a pushing force of between 3 lbs (1361 grams) and 5 lbs (2268 grams) depending on the number of two-inch loops through which the tubular coil was wound.
• It is therefore appreciated that other dimensions may be used for devices intended for use in endoscopes having working channels of other sizes. Moreover, the device may be used outside an endoscope, where it is not limited by the size of the working channel.
• From the foregoing examples, it will be appreciated that a flexible surgical clip applier, suitable for use through an endoscope is hereby provided. The device is capable of effecting a pushing force far in excess of the previously considered limitation of approximately 200 grams for a mechanical system sized to be used through an endoscope. See C. Paul Swain, “What Endoscopic Accessories Do We Really Need?”, Emerging Technologies in Gastrointestinal Endoscopy,Gastrointest. Endosc., Vol. 7, No. 2, pp. 313-330 (April 1997), discussed above. This substantial force permits clips to be forced over tissue and thereby makes available clip clamping, closure, and ‘suturing’ in an endoscopic procedure.
• There have been described and illustrated herein embodiments of a flexible surgical clip applier. While particular embodiments of the invention have been described, it is not intended that the invention be limited thereto, as it is intended that the invention be as broad in scope as the art will allow and that the specification be read likewise. Thus, while particular materials have been disclosed, it will be appreciated that other materials can be used as well. In addition, while particular dimensions have been disclosed, it will be understood that other suitable dimensions can be used as well. Also, while the device has particularly been described for use in endoscopic procedures, where a great need exists for such a device, it will be appreciated that flexible, non-endoscopic devices are considered within the scope of the invention. For example, the tubular coil may have a substantially shorter length and the device may be used through body orifices such as the ear canal, the nasal passages, and through the larynx and trachea. By way of another example, elements of the device may have substantially larger dimensions and the device can be used through a trocar port. Furthermore, while both jaws are shown rotatable about a clevis, it will be appreciated that only one jaw need be rotatable relative to the other. Also, while two clip guides, one on each jaw, are shown, it is recognized that only a single clip guide on one of the jaws is required. Moreover, while the device of the invention is described as having two end effector wires, it will be appreciated that a single control wire may be used which is coupled to at least one of the jaws, and the other jaw may be stationary or mechanically linked to also close and open upon actuation of the single end effector wire. Also, while the device has been described with respect to a clip-advancing wire and end effector wires, it will be appreciated that reference to the ‘wires’ is intended to also include non-metal filaments, multifilamentary constructs, such as cables, and coils. In addition, while the end effector wires when subject to a tensile force create a compressive force on the tubular coil which effectively increases its tensile capability to facilitate pushing a clip over clamped tissue without exceeding the tensile limitation of the coil, it is recognized that other mechanisms may be used to increase the tensile limitation of the coil. For example, a preferably flat and preferably wire ribbon may be coupled to the inside the coil to limit the amount by which the coil can be stretched. Furthermore, while the ability to provide a relative high pushing force at the distal end of a clip-advancing wire is disclosed with respect to a clip applier, it is recognized that such capability has application to instruments other than clip appliers; for example, for endoscopic staplers, lithotriptors, or any other instrument where it is desired to hold tissue and apply a pushing force, such as a device for tagging. It will therefore be appreciated by those skilled in the art that yet other modifications could be made to the provided invention without deviating from its spirit and scope as claimed.

Claims (16)

1-34. (canceled)

35. A flexible surgical device, comprising:

a) a flexible outer tubular member having proximal and distal ends;

b) a flexible advancing element extending through said tubular member and having proximal and distal ends; and

c) a handle coupled to said flexible outer tubular member and to said flexible clip-advancing element and adapted to move said advancing element distally relative to said tubular member, wherein said flexible advancing element, said tubular member, and said handle are adapted such that said handle under manual application of force can cause said advancing element to provide a distal pushing force of at least 500 grams at said distal end of said advancing element.

36. A flexible surgical device according toclaim 35, wherein:

said advancing element provides a distal pushing force of at least 1000 grams at said distal end of said advancing element.

37. A flexible surgical device according toclaim 35, wherein:

said advancing element provides a distal pushing force of at least 1500 grams at said distal end of said advancing element.

38. A flexible surgical device according toclaim 35, wherein:

said advancing element provides a distal pushing force of at least 2000 grams at said distal end of said advancing element.

39. A flexible surgical device according toclaim 35, wherein:

said outer tubular member is a flat wire wound tubular coil.

40. A flexible surgical device according toclaim 35, further comprising:

d) an end effector assembly at said distal end of said tubular member; and

e) at least one control wire extending through said tubular member, said control wire having a proximal end coupled to said handle such that operation of said handle causes relative proximal and distal movement of said at least one control wire relative to said outer tubular member, and a distal end coupled to said end effector assembly such that movement of said at least one control wire relative to said outer tubular member causes operation of said end effector.

41. A flexible surgical device according toclaim 40, wherein:

when said handle is operated to cause said at least one control wire to be moved proximally relative to said outer tubular member, said at least one control wire goes into tension and places a compressive force on said outer tubular member, thereby increasing an effective tensile limitation of said outer tubular member.

42. A flexible surgical device according toclaim 40, further comprising:

f) an inner sheath extending within the outer tubular member, said sheath including a first lumen for said advancing wire, at least one second lumen for said at least one control wire, said advancing wire extending through said first lumen and said at least one control wire extending through said at least one second lumen.

43. A flexible surgical device according toclaim 42, wherein:

said sheath has a non-circular cross-sectional shape.

44. A flexible surgical device according toclaim 40, wherein:

said end effector assembly includes a pair of jaws.

45. A flexible surgical device according toclaim 44, wherein:

at least one of said pair of jaws is rotatable relative to the other of said pair of jaws.

46. A flexible surgical device according toclaim 35, wherein:

said distal end of said advancing element is provided with a structure adapted to push a surgical clip.

47. A flexible surgical device according toclaim 35, wherein:

said distal end of said tubular member is provided with a clip chamber adapted to hold a plurality of surgical clips.

48. A flexible surgical device according toclaim 35, wherein:

said outer tubular member has an outer diameter not exceeding 3.2 mm.

49. A flexible surgical device according toclaim 35, wherein:

said outer tubular member has a length of 150 cm to 250 cm.

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