GB2482638A

GB2482638A - Suture device

Info

Publication number: GB2482638A
Application number: GB1120371.8A
Authority: GB
Inventors: Hiroyuki Asano; Yoshinori Mizumoto
Original assignee: MIZUTEC CO Ltd; Piolax Medical Devices Inc
Current assignee: MIZUTEC CO Ltd; Piolax Medical Devices Inc
Priority date: 2009-05-26
Filing date: 2010-05-18
Publication date: 2012-02-08
Anticipated expiration: 2030-05-18
Also published as: GB201120371D0; GB2482638B; DE112010002096T5; WO2010137256A1; JPWO2010137256A1; JP5314756B2

Abstract

Provided is a suture device capable of reliably inserting a suture needle into a target portion of a tissue. A suture device (10) comprising: a suture needle (20) which has a needle section (21) consisting of a shape memory alloy, having a pointed tip, and having provided at the tip thereof a needle hole (23) through which a suture thread can be passed, and also has an operation thread (28) which is connected to the base end of the needle section (21) through a connection section (27) and moves the needle section (21) in a predetermined direction; and a tube-like member (30) which slidably contains the suture needle (20). The tip of the tube-like member (30) comprises a pointed piercing section (33), and the suture needle (20) is configured to extend and retract within the inner periphery of the piercing section (33).

Description

Title of the hventjon

SUTURING rNSTRuNrENT

Technical Field

[0001] The present invention relates to a suturing instrument in which a tissue of a living body, for example, incised to be depressed like a crater by excising a tumor, a polyp or the like from the tissue is sutured with suture thread.

Baekgrond Art [0002] A tumor, a polyp or the like formed in an inner wall of the stomach, the large intestine or the like has been heretofore excised in concurrence with endoscopic inspection. That is, after an endoscope is stopped short of a target such as a tumor, a polyp or the like, a knife, a snare or the like is inserted in the body through a lumen of the endoscope and the tumor, the polyp or the like is excised with the knife, the snare or the like while visually recognized by the endoscope. In this manner, the tumor, the polyp or the like can be excised without any large-scale surgical operation on the body so that the burden imposed on the patient can be lightened remarkably [0003) The tissue of the living body from which the tumor, the polyp or the like has been excised has marginal wall portions separated by a crater-like depression, an operative wound or the like. As a result, bealing the tissue may be retarded or hyperplasia of the tissue may occur easily. For this reason, it is preferable that the separated wail portions of the tissue are sutured with suture thread after an excision operation of the polyp or the like to quicken benlixig of the excised region. This suturing can be performed such that a suture needle having a front end with a suture thread attached is stuck into the separated wall portions to pass the suture thread through the two wall portions and then the suture thread is fastened suitably.

[0004] A suturing instrument inchgling a tubular needle assembly, a puncture chip fixed to a front end portion of the needle assembly, shaped like a cylinder, curved like an arch and having a pointed front end obliquely cut, a long tubular knot arrangement assembly slidably disposed on an outer circumference of the needle assembly, and a hoop member disposed inside the needle assembly, coming in and out of the front end of the puncture chip and gripping a suture thread, has been disclosed in Patent Document 1. The hoop member is spread and cpened like a pantograph when the hoop member is protruded from the front end of the puncture chip. The hoop member is folded and contained in the puncture chip by being puUed into the puncture chip.

[0005] When the suturing instrument is used for suturing separated wall portions, the hoop member with the suture thread held therein is first contained in the needle assembly. After the front end portion of an insertion tube of an endoscope is then moved to a place near a target tissue, the sut-urmg instrument is inserted through a lumen of the endoscope, the puncture chip at the front end of the needle assembly is protruded from the front end of the lumen of the endoscope and the puncture chip is stuck into a predetermined place of one wall portion of the tissue. Then, the needle assembly is pushed in so that the puncture chip is passed through the one wall portion.

Then, the hoop member is protruded from the front end of the puncture chip arid spread and opened to thereby release the suture thread from the hoop member, so that the suture thread is passed thxough the one wall portion.

[0006] Then, the hoop member is pulled into the needle assembly, the needle assembly is drawn out of the wall portion, the suture thread passed through the wall portion is caught in the spread and opened hoop member again, and the hoop member is moved back so as to be contained in the needle assembly. In this state, the puncture chip is stuck into the other all portion of the tissue. Then, the suture thread is passed through the other wall portion in the same procedure as desctibed above and the suture thread passed through the two wall portions s fastened suitably to thereby suture the tissue.

Prior Art Document

Patent Document [0007] Patent Document 1: JP-2004-508 128-A

Summary of the Invention

Problems that the Invention is to Solve [0008] In Patent Document 1, the puncture chip at the front end of the needle assembly is designed to be stuck directly into wall portions of a tissue. There is however a possibility that the front end portion will be blurred or bent to make it impossible to stick the puncture chip into the target place accurately when the puncture chip is stuck into the tissue because the puncture chip is shaped like a needle thin enough to be stuck into the tissue. For this reason, there is a problem that it takes a long time for the suturing work or it is difficult to perform suturing in an appropriate position.

[0009] An object of the invention is to provide a suturing instrument which can stick a suture needle into a target position of a tissue surely.

Means for Solving the Problcns [0010] Inventive aspect I provides a suturing instrument for suturing a tissue with a suture thread, including: a suture needle having a needle portion made of a shape memory alloy, having a shape pointed at its front end and provided with a needle's eye for passing a suture thread through at its front end portion, and an operation wire connected to a base end portion of the needle portion through a connection portion and provided for moving the needie portion in a predctexmined direction; and a tubular member which slidably contains the suture needle, wherein a front end of the tubular member forms a pointed puncture portion such that the suture needle comes in and out of an inner circumference of the puncture portion.

[0011] For use of the suturing instrinnent. the suture needle with a suture thread passed through its needle's eye is first contained in the tubular member, and then the tubular member is inserted in a body through a lumen or the like of an endoscope so that the puncture portion at the front end of the tubular member is made to reach the side in front of a tissue depressed Like a crater or cut off and necessary to be sutured, for example, because a tumor, a polyp or the like is excised.

[0012) Then, when the target is set at a predetermined position in one of separated wall portions of the tissue, the puncture portion of the tubular member is stuck into the predetermined position to alii the tubular member with the predetermined position.

[0013) Then, the suture needle is pushed out so that the suture needle is protruded from the puncture portion and stuck into the predetermined position of the tissue.

The suture needle is further pushed so that the suture needle is protruded from the other separated wall portion of the tissue. As a result, the suture needle and the suture thread are passed through the two separated wail portions of the tissue.

[0014] In this state, while one end of the suture thread is held by forceps or the like, the suture needle is pulled out of the two wall portions of the tissue to thereby leave the suture thread passed through the two wall portions of the tissue. The suture thread is fastened suitably so that the separated wall portions of the tissue can be sutured.

[0015] The suturing instrument is designed so that the puncture portion of the tubular member is stuck into the predetermined position of the tissue before the suture needle is stuck into the predetermined position of the tissue. On this occasion, because the tubular member containing the suture needle is larger than the suture needle, the tubular member can be stuck into while aligned with the predetermined position of the tissue surely with neither displacement nor blurring. Then, by protruding the suture needle from the puncture portion, the suture needle can be stuck into the target position of the tissue surely.

[0016] In this manner, because the puncture portion of the tubuJar member thicker than the suture needle is stuck into the predetermined position of the tissue so that the tubular member can be aligned and fixed before the suture needle is stuck into the tissue, the suture needle can be stuck into the target position stably and surely.

[0017] Inventive aspect 2 provides, based on Inventive aspect 1, the suturing instrument, wherein the tubular member has a puncture tube extending linearly with a predetermined length to form the puncture portion at its front end portion, and an operation tube connected to a base end side of the puncture tube, and wherein the operation tube is formed like a coil in which a wire material is [0018] According to the above co figuration, even wben the suture needle is bent, the suture needle can be contained while expanded linearly by the puncture tube extending linearly. Because the puncture tube extends linearly, the predetermined position of the tissue can be set as a target easily, so that the puncture portion can be stuck into the predetermined position of the tissue. Because the coil-like operation tube is connected to the base portion side of the puncture tube, the tubular member can be inserted while bent flexibly along the bent path of an endoscope or the like.

[0019] Inventive aspect 3 provides, based on Inventive aspect 1, the suturing instrument, wherein the tubular member has a puncture tube extending linearly with a predetermined length to form the puncture portion at its front end portion, and an operation tube connected integrally to a base end side of the puncture tube, and wherein a plurality of slits extending with a predetermined length along a circumferential direction are formed in the operation tube at regular intervals along an axial direction.

[0020] According to the above configuration, also, the bent suture needle can be contained while expanded linearly by the puncture tube extending linearly. The puncture portion can be stuck into the predetermined position of the tissue surely Because the operation tube integrally connected to the base end side of the puncture tube is provided with slits which are formed at regular intervals along an axial direction so as to extend with a predetermined length along a circumferential direction, the operation member can be inserted while bent flexibly along the bent path of an endoscope or the like. Because the puncture tube and the operation tube are integrated with each other; there is merely little kinking in a boundary portion between the puncture tube and the operation tube so that workability can be improved.

[0021] Invenlive aspect 4 provides, based on any one of Inventive aspects I to 3, the suturing instrument, wherein a transfer tube is disposed on an outer circumference of the tubular member to allow the transfer tube to slide.

[0022] According to the above configuration, because the transfer tube is slidably disposed on the outer circumference of the tubular member, the inner circumference of a lumen or the like of an endoscope can be prevented from being damaged even when the transfer tube is inserted in the lumen or the like of the endoscope in the condition that the tubular member containing the suture needle is further contained in the transfer tube so that the pointed puncture portion of the tubular member is contained in the transfer tube.

[0023] Inventive aspect 5 provides) based on any one of Inventive aspects I to 4, the suturing instrument, wherein the needle portion of the suture needle is formed so that a portion stuck into a tissue is made of flat wire or triangular wire shaped like a triangle in sectional view, and wherein at least one part of the portion stuck into the tissue is given a shape curved while a flat surface side of the flat wire or triangular wire faces outward.

[0024] According to the above configuration, because the needle portion is made of flat wire or triangular wire shaped like a triangle in sectional view, the flat portion of the flat wire or triangular wire hardly comes into contact with the inner circumference of the tubular member when the operation wire is pushed out and in to move the suture needle into the tube to contain the suture needle in the tubular member or to protrude the suture needle from the tubular member. That is, because opposite side portions of the flat wire or corner portions of the triangular wire mainly come into contact with the inner circumference of the tubular member, sliding resistance of the needle portion to the inner circumference of the tubular member can be reduced. As a result, the operation of pushing out and in the suture needle becomes easy so that the suture needle can be moved smoothly relative to the tubular member. e

[0025} Because the needle portion is provided as flat wire or triangular wire, the sectional area can be reduced while the width necessary for providing the needle's eye can be kept sufficient. Because the sectional area is reduced remarkably compared with the case where the needle portion is provided as round wire or the like having a thickness necessary for forming the needle's eye, the needle portion can be passed through the tissue easily and the size of the bole formed in the tissue can be reduced to lighten damage of the tissue, [00261 Inventive aspect 6 provides, based on any one of Inventive aspects 1 to 5, the suturing instrument, wherein the needle portion of the suture needle has a linear portion extending linearly with a predetermined length from the front end portion, and wherein the needle portion is curved from a base portion side of the linear portion.

[0027] According to the above configuration, even when the distance between one wail portion and the other wall portion in the tissue to be sutured is long, the linear portion extending linearly in the suture needle can be stuck in the wall portions surely to pass the suture thread through the two wall portions of the tissue so that the suturing [0028] Inventive aspect 7 provides, based on any one of Inventive aspects 1 to 6, the suturing instrument, wherein the needle portion of the suture needle is bent at a curvature angle 0 of 190 to 540 degrees when a position starting bending from the linear portion at the base end portion is A, a position of the bent portion of the needle portion farthest from an axial line of the operation wire is B, a front end position of the needle portion is C, a midpoint between the position A and the position B is a center 0, and the curvature angle e is an angle by which a line connecting the position C and the center 0 rotates around the center 0 relative to a line connecting the position A and the center 0.

[0029] According to the above configuration, because the front end portion of the needle portion is curved at a curvature angle 0 larger than 190 degrees, the needle portion is curved gradually largely as the front end portion of the needle portion is protruded from the puncture portion of the tubular member. For this reason, because the front end of the needle portion is curved so that the suture thread can be protruded so as to move largely away from the affected part after the needle portion is stuck into at least one pair of wall portions of the tissue to be sutured, the suture thread passed through at least one pair of wall portions can be held by forceps or the like. Because the needle portion stuck into the tissue is hardly dropped out of the tissue in the middle of operation, the suturing operation can be performed easily.

[0030] Inventive aspect 8 provides, based on any one of Inventive aspects 1 to 7, the suturing instrument, wherein the needle portion of the suture needle has a small curvature portion and a large curvature portion in a shape curved from the front end to the base portion side.

[0031] According to the above coniiguration because the needle portion has a small curvature portion and a large curvature portion, the needle portion is bent to thaw a sharp curve when the front end portion of the needle portion is gradually pushed out of the puncture portion of the tubular member so that the large curvature portion is protruded. Thus, the needle tip protruded from the tissue is curved to move away from the tissue so that the needle tip once stuck into the tissue can be prevented from being dropped out of the tissue. The suture thread passed through the needle's eye also moves away from the tissue so that the suture thread can be held by forceps or the like easily. Accordingly, the suturing work can be performed easily.

Effect of the Invention [0032] According to the invention, configuration is made so that the puncture portion of the tubular member thicker than the suture needle is stuck into a predetermined position of a tissue before the suture needle is stuck into the tissue. Accordingly, the tubular member can be aligned and fixed, so that the suture needle can be stuck into the target position stably and surely.

Brief Description of the Drawings

[0033] [Fig. 1] A perspective view showing a first embodiment of a suturing instrument according to the invention.

[Fig. 2] An enlarged perspective view of main part of the suturing instrument [Fig. 3] Views showing a suture needle in the suturing instrument, in which (a) is an enlarged perspective view of main part thereof, Cb) is an enlarged side view of main part thereof, and (c) is an enlarged side view of main part showing another structure of the suture needle.

[Fig. 4] Views showing the front end shape of the suture needle in the suturing instrizxnent, in which (a) is an enlarged perspective view, (b) is an enlarged plan view, and (c) is a sectional view taken along the line G-G in (b).

[Fig. 5] Views showing the front end shape of a tubular member in the suturing instrument, in which (a) is an enlarged perspective view, and (b) is an enlarged side view, [Fig. 6) Views showing states of use of the suturing instrument, in which (a) is a sectional view in a first use state, (b) is a sectional view in a second use state, (c) is a sectional view in a third use state, and (d) is a sectional view in a fourth use state.

[Fig. 7] Views showing states of use of the suturing instrument, in which (a) illustrates a first use state, (b) illustrates a second use state, and (c) illustrates a third use state.

[Fig. 81 Views showing states of use of the suturing instrument, in which (a) illustrates a fourth use state, (b) illustrates a fifth use state, and (c) illustrates a sixth use state.

[Fig. 9) An enlarged side view of main part showing a second embodiment of the suturing instrument according to the invention.

[Fig. 10] Views showing a third embodiment of the suturing instrument according to the invention, in which (a) is an enlarged perspective view of main part, and (b) is an enlarged side view of main part.

[Fig. 11] Views showing a fourth embodiment of a suture needle according to the invention, in which (a) illustrates main part thereoL (b) illustrates a first use state, (c) illustrates a second use state, (d) illustrates a third use state, and (e) illustrates a fourth use state.

[Fig. 12] Views showing a fifth embodiment of the suture needle according to the invention, in which (a) illustrates main part thereof, (b) illustrates a first use state, (c) illustrates a second use state, (d) illustrates a third use state, and (e) illustrates a fourth use state.

[Fig. 13] Views showing a sixth embodiment of the suture needle according to the invention, in which (a) illustrates main part thereof, (b) illustrates a first use state, (c) illustrates a second use state, (d) illustrates a third use state, and (e) illustrates a fourth use state.

[Fig. 14) Views showing a seventh embodiment of the suture needle according to the invention, in which (a) illustrates main part thereof, (b) illustrates a first use state (c) illustrates a second use state, (d) illustrates a third use state, and (e) illustrates a fourth use state.

[Fig.. 15] Views showing an eighth embodiment of the suture needle according to the invention, in which (a) is an enlarged perspecnve view of main part thereof, (b) is a sectional view taken along the anow Line F-F in (a), and (c) is an enlarged perspective view of main part showing another shape of the needle portion in the same embodiment.

[Fig. 16] A perspective view showing a ninth embodiment of the suturing instrument according to the invention.

Mode for Carrymg Out the hivention [0034] A first embodiment of a suturing instrument according to the invention will be described below with reference to Figs. I to 8 The suturing instrument 10 according to the invention is used for occluding a tissue P again by suturing separated wall portions V of the tissue P after a tumor a polyp or the like generated in an inner wall of the stomach, the large intestine or the like is excised (see Figs. 7 and 8).

{0035] As shown in Fig. 1, the suturing instrument 10 in this embodiment has: a suture needle 20 to which a suture thread I (see Figs. 6 to 8) for suturing the wall portions V is attached; a tubujar member 30 in which the suture needle 20 is contained so as to be slidable; a transfer tube 40 which is disposed outside the tubular member 30 so as to be slidable; and an operation device 50 for. operating the suture needle 20, the tubular member 30 and the transfer tube 40.

[0036] The suture needle 20 will be described rst in conjunction with Figs 2 and 3.

The suture needle 20 has a needle portion 21, and an operation wire 28 coni,ected to a base end portion of the needle portion 21 through a connection portion 27.

[0037] The operation wire 28 serves for moving the needle portion 21 connected to its end in a predetermined direction. In this embodiment, the operation wire 28 is made of a linear wire material which extends with a predetermined length For example, stainless steel, Ni, W, piano wire, phosphor bronze or superelastic alloy such as Ni-Ti system, Ni-Ti-X (X'=Fe, Cu, V, co, etc.), Cu-Al-Ni system or Cu-Zn-X (XSi, Al, Sn, Fe, etc.) or synthetic resin such as Nylon or polyester can be used as the material of the operation wire 28. A stranded wire made by suitably twisting plural wire materials may be used as the operation wire 28. The form of the operation wire 28 is not particularly limited.

[0038] On the other band, the needle portion 21 is made of a shape memory alloy, has a shape tapered off toward a front end 22a and provided with front end portion 22 so that a suture thread T can be inserted through a needle's eye 23. The needle portion 21 in this embodiment is formed so that a predetemjined shape is given to a flat wire extending like a belt with a predeterr.nixied length.

[0039] As shown in (a) and (b) of Fig. 4, opposite side edges 22b and 22b of the front end portion 22 of the needle portion 21 are inclined so that the front end portion 22 is formed into a tapered shape which is tapered off toward the foremost end but widened gradually from one flat surface side to the other flat surface side (see (c) of Fig. 4).

As a result, the front end portion 22 of the needle portion 21 is shaped like a trapezoid in sectional view and the front end 22a is pointed. This front end 22a forms a portion which is stuck into the tissue p in the invention.

[0040] The flat wire forming the needle portion 21 is shaped like a belt which is rectangular in section and which has a predetermined plate width W (see (a) of Fig. 3) and a plate thickness t (see (b) of Pig. 3) smaller in size than the plate width W. A flat wire having a plate width W of 0.5 to 2.0mm and a plate thickness of 0.1 to 0.4mm is preferably used. The needle's eye 23 formed at the front end of the needle portion is shaped like a long hole which gets long along an extending direction of the needle portion 21. The transverse diameter of the needle's eye 23 is set to be in a range of 0.5 to 2.0mm and the conjugate diameter of the needle's eye 23 is set to be in a range of 0.5 to 1.5mm. The needl&s eye 23 may be shaped like a circle, a square, a polygon, etc. The shape of the needie's eye 23 is not particularly limited.

[0041] The needle portion 21 made of a flat wire is given a shape curved while one flat surface side of the front end portion 22 faces outward. In this embodiment, the needle portion 21 is given a shape such that the front end portion 22 is curved toward the base end portion 26 and further curved to make one revolution like a ring so that the front end portion 22 is turned in reverse to the base end portion 26 (see (a) and (b) of Pig. 3). As shown in (a) and (b) of Fig. 3, the needle portion 21 has a linear portion 24 which extends linearly with a predetermined length from the front end portion 22 toward the base end portion 26. A bent portion 25 formed to make one revolution like a ring is provided so as to extend from the base end of the linear portion 24.

[00421 As shown in (b) of Fig. 3, when a position where the needle portion 21 begins to be bent from the linear portion of the ba.se end portion 26 is defined as A, a position where the bent portion 25 of the needle portion 21 is farthest from the axial line of the operation wire 28 is defined as B, a front end position of the needle portion 21 is defined as C, a midpoint between the position A and the position B is defined as a center 0, and an angle by which a line connecting the position C and the center 0 rotates around the center 0 with respect to a line connecting the position A and the center 0 is defined as a curvature angle 0, the curvature angle 0 is formed to be in a range of 190 to 540 degrees. In this embodiment, the curvature angle 0 is set to be about 425 degrees (360 degrees + 65 degrees). If the curvature angle 0 is smaller than 190 degrees, the needle portion 21 is hardly stuck into the wail portions V of the tissue P. If the curvature angle 0 is larger than 450 degrees, handling property from the operator's hand is lowered.

[00431 When the maximum diameter of the bent portion 25 of the needle portion 21 is defmed as R (distance between the position A and the position B), the maximum diameter R may preferably be in a range of S to 20mm. If the maximum diameter R is smaller than 5mm, the elastic restoring force of the needle portion 21 becomes so large that resistance at putting the needle portion 21 in the tubular member 30 becomes large to make it diflicuit to put the needle portion 21 in the tubular member 30. On the other hand, if the maximum diameter l is Larger than 20mm, the elastic restoring force of the needle portion 21 becomes so small that the needle portion 21 is hardly stuck into the wall portions V of the target tissue P. [0044] As the shape memory alloy used in the needle portion 21, Ni-Ti system, Ni-Ti-X (X=Fe, Cu, V, Co, etc.), Cu-Al-Ni system, Cu-Zn-X (X=Si, Al, Sn, Fe, etc.) or the like can be used. The shape memory alloy used in the needle portion 21 has a transition point not higher than ordinary temperature, so that the shape given to the needle portion 21 is kept so as to exhibit superelasticity when the suture needle 21 is contained in the tubular member 30 and the transfer tube 40 or used in a human body.

As another method, the transition point may be set to be not lower than the human body's temperature so that the needle portion 21 can be restored to its original shape by a suitable heating unit.

(0045] As shown in (b) of Fig. 3, the base end portion 26 of the needle portion 21 is.

lapped over a belt-like connection piece 28a connected to the front end portion of the operation wire 28, and bonded to the belt-like connection piece 28a by the connection portion 27 made of wax, solder or an adhesive agent, so that the operation wire 28 is connected to the base end portion 2.6 of the needle portion 21 through the connection portion 27.

[00461 The needle portion 21 of the suture needle 20 may have a structure shown in (c) of Fig. 3, arid the shape given to the needle portion 21 is not particularly limited.

The needle portion 21 shown in (c) of Fig 3 has a linear portion 24 made of flat wire and extending linearly from the front end portion 22 in the same manner as the needle portion 21 shown in (a) and (b) of Fig. 3. The linear portion 24 is formed to be substantially parallel to the base end portion 26 through the bent portion 25, so that the needle portion 21 is bent to be substantially Ti-shaped as a whole. The curvature angle (3is about 245 degrees (180 degrees + 65 degrees).

[0047] The suture needle 20 having the aforementioned structure is designed to be slidably contained in the tubular member 30 shaped like a pipe. Referring to Figs. 2, and 6 the tubular member 30 in this embodiment has a puncture tube 31 extending linearly with a predetermined length, and an operation tube 35 connected to the base end side of the puncture tube 31.

[0048] The puncture tube 31 has a pointed puncture portion 33 provided in its front end portion. The puncture portion 33 is a portion stuck into the wail portions V of the target tissue P (see Fig. 7) and designed so that the suture needle 20 can go in and out of the inner circuxference of the puncture portion 33 (see Fig. 6), and also a portion designed so that the needle portion 21 of the suture needle 20 formed into a predetermined shape can be drawn out. and put iii.

[0049] As shown in Fig. 5, the front end portion of the puncture tube 31 is cut obliquely at a predetermined angle with respect to a segment S along the axial direction of the puncture tube 31 to thereby form the pointed puncture portion 33 at the front end of the puncture tube 31.

[0050] The length L from the front end to the base end of the puncture portion 33 shown in (b) of Fig. 5 may preferably be in a range of 2 to 5mm. If the length L of the puncture portion 33 is smaller than 2rnni. the depth of puncture of the wall portions V of the tissue P is so insufficient that it is difficult to align the tubular member 30 with the wall portions V stably. On the other hand, if the length L is larger than 5mm, the puncture portion 33 is stuck into the wall portions V of the tissue P more deeply than necessary so that invasion of the tissue P increases.

[0051] The operation tube 35 connected to the base end portion of the puncture portion 33 Is formed from flat wire coiled at intervals of a predetermined pitch in order to enhance flexibility of the operation tube 35. In this embodiment, the operation tube 35 is fotmed from solid-coiled flat wire. The front end portion of the operation tube 35 is disposed on the outer circumference of the base end portion of the puncture tube 31 and bonded thereto by solder, an adhesive agent or the like to thereby connect the operation tube 35 to the puncture tube 31 [0052] For example, stainless steel, Ni, W, phosphor bronze or shape memory alloy such as Ni-Ti system, Ni-Ti-X (X=Fe, Cu, V Co, etc.) or Cu-AlNi system, Cu-Zn-X (X=Si, Al, Sn, Fe, etc.) can be used as the material of each of the puncture rube 31 and the operation tube 35. Stainless steel having high rigidity may preferably be used as the puncture tube 31 so as to be easily stuck into the wall portions V of the tissue P. Also, stainless steel having high rigidity may preferably be used as the operation tube in consideration of pushabiity, torque transmissibility, etc. lB [0053] The transfer tube 40 which can slide on the tubular member 30 is disposed on the outer circumference of the tubular member 30. The transfer tube 40 is made of a synthetic resin such as Nylon elastomer, polyethylene5 polyurethane, polyether block amide, polyvinyl chloride, vinyl acetate, fluorocarbon resin, etc. The transfer tube 40 functions to prevent the outer circumference of the tubular member 30 from directly touching the lumen inner circumference of the endoscope not shown.

[0054] The suture needle 20, the tubular member 30 and the transfer tube 40 are operated by the operation device SO.

[0055] As shown in Fig. 1, the operation device 50 has a transfer tube operating portion 51 shaped like a pipe, a tubular member operating portion 53 shaped like a pipe and slidably contained in the transfer tube operating portion 51, and a suture needle operating portion 55 disposed on the outer circumference of the tubular member operating portion 53 so as to be slidably movable relative to the tubular member operating portion 53. The tubular member operating portion 53 has an insertion tube 53a provided on its front end side, and a guide tube 53b provided with guide grooves formed on its base end side. The insertion tube 53a is inserted in the transfer tube operating portion 51 while the suture needle operating portion 55 is slidably mounted on the outer circumference of the guide tube 53b [0056] The base end portion of the transfer tube 40 is connected to the front end portion 51a of the transfer tube operating portion 51. The base end portion of the operation member 35 of the tubular member is connected to the not-shown front end portion of the insertion tube 53a of the tubular member operating portion 53. In addition, the base end of the operation wire 28 of the suture needle 20 is connected to the center of the front end of the suture needle operating portion 55.

[0057J By operating the operation device 50 having the aforementioned structure, the suture needle 20, the tubular member 30 and the transfer tube 40 operate as follows.

That is, when the transfer tube operating portion 51 of the operation device 50 is moved, the transfer tube 40 moves accordingly. When the tubular member operating portion 53 is slid back and forth in the axial direction relative to the transfer tube operating portion 51, the tubular member 30 moves back and forth relative to the transfer tube 40.

[0058] When the suture needle operating portion 55 is slid back and forth relative to the tubular member operating portion 53, the suture needle 20 moves back and forth relative to the tubular member 30. That is, because the operation wire 28 of the suture needle 20 moves back and forth in accordance with sliding of the suture needle operating portion 55, the needle portion 21 connected to the front end of the operation wire 28 comes in and out of the inner circumference of the puncture portion 33 of the puncture tithe 31 of the tubular member 30.

[0059] Suitable operation of the operation device 50 as described above permits the sliding operation of the tubular member 30 relative to the transfer tube 40 and the sliding operation of the operation wire 28 and the in-and-out operation of the needle portion 21 relative to the tubular member 30 In the structure of the operation device SO, because the transfer tube operating portion 51 and the tubular member operating portion 53 can be rotated in a predeteniiined direction, the direction of the foremost end of the puncture portion 33 can be changed, for example, by rotation of the tubular member 30 relative to the transfer tube 40.

[0060] Operation of the tubular member 30 and the suture needle 20 in the suturing instrument 10 will be described next with reference to Fig. 6. Although the needle portion 21 of the suture needle 20 in this embodiment is formed into a shape shown in Figs. I and 2, the suture needle 20 is ordinariLy contained in the tubular member 30.

[0061] That is, when the needle portion 21 protruded from the puncture portion 33 and formed into a predetermined shape is contained in the puncture tube 31 against its elastic force, the needle portion 21 is gradually pulled in while extended through the inner circumferential edge of the puncture portion 33 so that the needle portion 21 thus extended flatly is contained and held in the inner circumference of the puncture tube 31 (see (a) of Fig. 6). If necessary, the needle portion 21 of the suture needle 20 is protruded from the inner circumference of the puncture portion 33 of the puncture tube 31 of the tubular member 30. That is, when the tissue P needs to be sutured with the suture needle 20, the needle portion 21 in a state show in (a) of Fig. 6 is protruded from the inner circumference of the puncture portion 33 of the puncture tube 31 through the operation wire 28 (see (b) of Fig. 5). The protruded needle portion 21 is gradually elastically restored by the elastic restoring force of the shape memory alloy (see (c) of Fig. 6). When the needle portion 21 is protruded outward to the utmost, the needle portion 21 is restored to Its original shape (see (d) of Fig. 6).

[0062] On this occasion, because the needle portion 21 of the suture needle 20 formed into a predetermined shape is contained in the puncture tube 31 of the tubular member 30 while extended flatly, elastic restoring force for restoration to its original given shape always acts on the needle portion 21-Accordingly, when the suture needle 20 moves to protrude the needle portion 21 from the inner circumference of the puncture portion 33, the needle portion 21 is protruded while elastically restored from the opening circumferential edge on the base end side of the puncture portion 33 which is the position where elastic restoration of the needle portion 21 can be started earliest, that is, the position nearest to the front end 22a of the needle portion 21 (see (b) and (e) of Fig. 6). For this reason, as shown in (a) of Fig. 5, opposite side edges of the needle portion 21 are protruded while guided by the opening circumferential edge on the base end side of the puncture portion 33.

[0063] Accordingly, when the needle portion 21 is protruded from the puncture portion 33, the needle portion 21 is protruded from the puncture portion 33 while the direction of the needle portion 21 is conected automatically so that opposite side edges of the needle portion 21 come into frictional contact with the opening circumferential edge on the base end side of the puncture portion 33 regardless of the angle at which the needle portion 21 is contained in the puncture tube 31. As a result, it is easy to predict the direction of protrusion of the needle portion 21 from the puncture tube 31.

[0054] Usage of the suturing instrument 10 congured as described above according to the invention will be described next with reference to Figs. 6 to 8.

[0065] Prior to operative treatment, as shown in Fig. 2, the needle portion 21 of the suture needle 20 is protruded from the inner circumference of the puncture pox-tion33 of the puncture tube 31 of the tubular member 30 and a suture thread T made of a wire material such as silk, Nylon, fluorocarbon resin, etc. is inserted in the needle's eye 23 of the needle portion 21 so as to be caught in the needle's eye 23.

[0066] Then, in a state where the transfer tube operating portion 51 of the operation device 50 is gripped and fixed, the tubular member operating portion 53 and the suture needle operating portion 55 are slid backward (in the direction of the operator's pulling toward the operator's hand). As a result, the tubular member 30 is pulled and contained in the transfer tube 40 and the suture needle 20 is pulled and contained in the tubular member 30. On this occasion, the needle portion 21 in the given shape is contained and held in the inner circumference of the puncture tube 31 while extended flatly by the inner circumferential edge of the puncture portion 33 (see (a) of Fig. 6).

PartIcularly, in this embodiment, because the puncture tube 31 extending linearly is used as a constituent member of the tubular member 30, the needle portion 21 of the suture needle 20 can be ectended linearly and contained surely even when the needle portion 21 is bent.

[0067] After the aforementioned preparations, the front end portion of the endoscope not shown is made to reach a target such as a tumor and a polyp by a cominon.ly known method and a knife or the like is inserted to excise the tumor, etc. or forceps or the like are inserted to hold and peel the tumor, etc. through a lumen formed in the endoscope or an annular snare is inserted through the lumen to trap and cut the root portion of the tumor, etc. to thereby excise the tumor or poiyp from the inner wall of the stomach and intestines etc. After the tumor or poiyp etc. is excised in this manner, the tissue P is in a state where the wall portions V and V are separated from each other due to a crater-like cavity, a surgical wound, etc. (see Fig. 7).

[0068) Then, while the transfer tube operating portion 51 of the operation device 50 is gripped, the suturing instrument 10 is inserted in the body through the lumen of the endoscope. On this occasion, in this embodiment, because the transfer tube 40 is disposed on the outer circumference of the tubular member 30 so that the tubular member 30 is covered with the transfer tube 40, the pointed puncture tube 31 of the tubular member 30 and the operation tube 35 made of a hard material such as stainless steel are prevented from touching the lumen of the end oscope so that the inner circumference of the lumen of the endoscope can be prevented from being damaged.

And, the coil-like operation tube 35 is prevented from being caught in the inner circumference of the lumen of the endoscope so as not to increase sliding resistance.

In this embodiment, because the coil-like operation tube 35 in which a wire material is wound is connected as a constituent member of the tubular member 30 to the base portion side of the puncture tube 31, the tubular member 30 can be inserted while bent flexibly along a bent path even when the lumen of the eridoscope is bent.

[0069] Then, the front end portion of the transfer tube 40 is made to reach the front side of one wall portion V of the tissue P to be sutured. In this condition, the Transfer tube operating portion Si of the operation device 50 is gripped and fixed and the tubular member operating portion 53 is slid forward (in the direction of the operator's pushing) to thereby protrude the puncture tube 31 of the tubular member 30 from the front end of the transfer tube 40.

[0070] While a predetermined position of the wall portion V is set as a target, the puncture portion 33 of the puncture tube 31 is stuck into the wall portion V with a predetermined depth as shown in (a) of Fig. 7 to thereby make it possible to align the tubular member 30 with the predetermined position of the wall portion V. [0071] On this occasion, because the puncture tube 31 extending linearly is provided in this embodiment, it is easyto set the target at the predetermined position of the wall * portion V, so that the puncture portion 33 can be stuck into the predetermined position of the wall portion V surely and with a predetemiined depth.

[0072] In a state where the puncture portion 33 is stuck into the wall portion V in the aforementioned manner, the suture needle operating portion 55 is slid forward relative to the tubular member operating portion 53 of the operation device 50 to protrude the needle portion 21 of the suture needle 20 from the inner circumference of the puncture portion 33 so that the front end 22a of the needle portion 21 is stuck into the predetermined position of the wall portion V as shown in (b) of Fig. 7.

[0073] Then, the suture needle operating portion 55 is further slid forward to thereby protrude the needle portion 21 from the inner circumference of the puncture portion 33.

On this occasion, the needle portion 21 in this embodiment has the linear portion 24 extending linearly with a predetermined length from the front end portion 22 (see Figs. 2 and 3). For this reason, even when the distance between the two wall portions V and V of the tissue P is long, the linear portion 24 extending linearly is stuck into the two wall portions V and V surely to make it possible to pass the suture thread through the two wail portions of the tissue so that the suturing work can be performed easily.

[0074] The suture needle operating portion 55 iS forther slid forward to thereby protrude the needle portion 21 greatly from the inner circumference of the puncture portion 33, so that the needle portion 21 is stuck into the other wall portion V of the tissue P to protrude the front end 22a of the needle portion 21 from the other wall portion V as shown in (c) of Fig. 7.

[00751 Then, when the suture needle operating portion 55 is further slid forward, the needle portion 21 is elastically restored to a curved state by the bent portion 25 so as to be separated from the wall portion V as shown in (a) of Fig. 8.

[0076] In this manner, the needle portion 21 is protruded from the puncture portion 33 until the needle portion 21 is elastically restored to the form of a U-shaped hook.

As a result, the suture thread T running through the needle's eyc 23 of the suture needle is passed together with the suture needle 20 through the two wail portions V and V of the tissue P. Then, the front end portions of the pair of wall portions V and V are gathered so as to come close to each other by the needle portion 21 elastically restored to the form of a Ushaped hook.

[0077] On this occasion, because the needle portion 21 is bent greatly) the state where the suture thread T is passed through the pair of wall portions V and V of the tissue P can be held while the suture thread I once passed through a wall portion V is prevented from being dropped out.

[0078) In the aforementioned condition, as shown in (b) of Fig. 8, one end of the suture tiiread T passed through the needle's eye 23 of the suture needle 20 (one end of the suture thread Tpaid out from the other wall portion V and supported by the needle's eye 23) is pulled while gripped by a gripping member I such as forceps to thereby draw out the suture thread T from the needle's eye 23 of the suture needle 20 so that the suture thread T is pulled out while passed through the pair of wall portions V and V of the tissue R [0079] Then, the suture needle operating portion 55 is slid backward relative to the tubular member operating portion 53 of the operation device 50 to thereby draw out the needle portion 21 of the suture needle 20 from the pair of wall portions V and V. Then, the tubular member operating portion 53 is slid backward relative to the transfer tube operating poition 51 of the operation device 50 to thereby pull out the puncture portion 33 of the puncture tube 31 from the one wall portion V. As a result, only the suture thread T is left passed through the pair of wall portions V and V as shown in (c) of Fig. 8, so that the pair of separated wall portions V and V of the tissue P can be sutured to occlude the tissue P when the suture thread T is fastened by a commonly known binder or the like.

[0080] In this manne; in the suturing inst-ument 10, before the front end 22a of the needle portion 21 of the suture needle 20 is stuck into a predetermined position of a wall portion V of the tissue P, the puncture portion 33 of the tubular member 30 is stuck into the predetennined portion of the wall portion V. On this occasion, because the tubular member 30 containing the suture needle 20 is thicker than the suture needle 20, the tubular member 30 can be aligned with the predetermined position of the wall portion V and stuck into the predetermined position of the wall portion V surely with neither displacement nor blurting compared with the case where the thin suture needle is directly stuck into the wall portion V. When the needle portion 21 of the suture needle 20 is then protruded from the inner circumference of the puncture portion 33, the suture needle 20 can be stuck into the target position of the wall portion V surely.

[0081} In this embodiment, because the needle portion 21 of the suture needle 20 is made of flat wire, opposite side portions of the flat wire mainly formIng the needle portion 21 can come into contact with the inner circumference of the tubular member to reduce sliding resistance of the needle portion 21 to the inner circumference of the tubular member 30 when the operation wire 28 is pushed inlout to contain the suture needle 20 in the tubular member 30 or to protrude the suture needle 20 from the tubular member 30. As a result, the pushing-inlout operation of the suture needle 20 becomes easy, so that the suture needle 20 can be moved smoothly relative to the tubular member 30.

[0082] Because the needle portion 21 is provided as fiat wire, the width necessary for providing the needle's eye 23 is secured sufficiently while the sectional area can be reduced remarkably compared with the case where the needle portion 21 is made of round wire or the like and has a thickness necessary for forming the needle's eye 23.

As a result, the needle portion 21 can be passed through the wall portion V of the tissue P easily and the hole formed in the wall portion V of the tissue P can be reduced to lighten damage of the tissue [00 83] In this embodiment, because the front end portion of the needle portion 21 is curved at a curvature angle 0 larger than 270 degrees, the needle portion 21 is curved gradually largely as the front end portion of the needle portion 21 is protruded from the puncture portion 33 of the tubular member 30. For this reason, after the needle portion 21 is stuck into the wall portions V and V of the tissue P, the front end portion 22 of the needle portion 21 is curved so that the suture thread T can be protruded to be wide apart from the tissue P. Accordingly, the suture thread T passed through at least one pair of wail portions V and V can be easily gripped by forceps or the like.

Because the needle portion 21 is hardly dropped out from the tissue into which the needle portion 21 is stuck, the suturing operation can be performed more easily.

[0084] Fig. 9 shows a second embodiment of the suturing instrument according to the invention. Parts substantially the same as those in the aforementioned embodiment are referred to by the same numerals and description thereof will be omitted.

[0085] The suturing instrument 1 Oa differs from that in the first embodiment in the structure of the tubular member 30. That is, the tubular member 30 has a puncture tube 31 extending linearly with a predetermined length arid provided with a puncture portion 33 formed at its front end portion, and an operation tube 35a connected integrally to the base end side of the puncture tube 31. Plural slits 37 extending with a predetermined length along the circumferential direction are formed at regular intervals along the axial direction in the operation tube 3 5a.

[0086] According to this embodiment, the bent suture uee die 20 can be expanded linearly and contained by the puncture tube 31 extending linearly and the puncture portion 33 can be stuck into a predetermined position of a wail portion V of a tissue P surely in the same manner as in the first embodiment. Because the slits 37 extending with the predetermined length along the circumferential direction are formed at regular intervals along the axial direction in the operation tube 35a connected integrally to the base end side of the puncture tube 31, the suturing instnirnent lOa can be inserted while flexibly bent along the bent path of the endoscope. Because the puncture tube 31 and the operation tube 35a are integrated with each other, there is merely little kink in a boundary portion between the puncture tube 31 and the operation tube 35a so that [0087] Fig. 10 shows a third embodiment of the suturing instrument according to the invention. Parts substantially the same as those in the aforementioned embodiment are referred to by the same numerals and description thereof will be omitted.

[0088) The suturing instrument I Ob differs from that in the aforementioned embodiment in the structure of the suture needle 20. That is, the suture needle 20 of the suturing instrument lOb has a needle portion 21 bent so as to be substantially U-shaped, and an operation wire 28a connected to the base end portion of the needle portion 21 and made of stranded wire. According to this embodiment, production cost can be reduced because the needle portion 21 has a simple given shape. In this embodiment, the curvature angle 0 (the angle by which a line connecting the position C and the center 0 rotates around the center 0) is about 235°.

[0089] Fig. 11 shows a fourth embodiment of the suturing instrument according to the invention. Parts substantially the same as those in the aforementioned embodiment are referred to by the same characters and description thereof will be omitted.

[0090] The suturing insti-ument I Oc in this embodiment differs from that in the aforementioned embodiment in the shape given to the needle portion 21. That is, the needle portion 21 of the suturing instrument lOc has a small curvature portion and a large curvature portion in the shape curved from the front end toward the base end side.

Specifically, as shown in (a) of Fig. 11, the needle portion 21 has a portion (first slow curve portion) 21a bent to draw a slow curve, a portion (first shaxp curve portion) 21b bent to draw a sharp curve, and a portion (second slow curve portion) 21 c bent to draw a slow curve again in a range of from the front end to the base end side. The shape of the needle portion 21 is given so that the curvature angle 0 (the angle by which a line connecting the position C and the center 0 rotates around the center 0) of the pointed front end portion is about 4500.

[00911 When the needle poxtion 21 is pushed Out through the operation wire 28 in the condition that the suture needle 20 is contained in the tubular member 30, the needle portion 21 is protruded gradually from the inner circumference of the puncture portion 33 of the tubular member 30 and elastically restored as shown in (b) to (e) of Fig. 11, so that the needle portion 21 is finally restored to the given shape shown in (a) of Fig. 11.

[0092] In this embodiment, the suture needle 20 has a first slow curve portion 21a, a first sharp curve portion 21b and a second slow curve portion 21c. Accordingly, when operation is made to suture the tissue P the first slow curve portion 21a is first protruded from the inner circumference of the puncture portion 33 of the tubular member 30 as shown in (b) and (c) of Fig II Because the first slow curve portion 21a draws a relatively slow curve, the first slow curve portion 21a can be stuck into a wall portion V of the tissue P. [0093] When the front end portion 22 of the needle portion 21 is further pushed out of the tubular member 30, the first sharp curve portion is protruded this time as shown in (d) of Fig. 11, Because the first sharp curve portion 21b is bent to draw a sharp curve compared with the first slow curve portion 21 a, the front end portion 22 of the needle portion 21 is suddenly bent backward so that the wall portions V and V into which the first slow curve portion 21a is stuck are hauled to the operator's hand side.

[0094] That is, because the first sharp curve portion 21 b is protruded so that the needle portion 2lis bent to draw a sharp curve when the first slow curve portion 21a is stuck into at least one pair of wall portions V and V of the tissue P to be sutured (see (d) of Fig. 11), the tip of the needle can move away from the tissue P to prevent the needle portion 21 from being dropped out again. Because the suture thread T passed through the needle's eye 23 also moves away from the tissue P so as to be gripped easily by forceps or the like, the suturing operation can be performed easily.

[0095] Fig. 12 shows a fifth embodiment of the suturing instrument according to the invention. Parts substantiaLly the same as those in the aforementioned embodiment are referred to by the same numerals and description thereof will be omitted.

[0096] The suturing instrument I Od in this embodiment differs from that in the aforementioned embodiment in the shape gven to the needle portion 21. That is, as shown in (a) of Fig. 12, the needle portion 21 of the suturing instrument lOd has a first slow curve portion 21a, a first sharp curve portion 21b, a second slow curve portion 21c) a second sharp curve portion 21d, and a third slow curve portion 21e.

[0097] According to this embodiment, when the needle portion 21 is pushed out of' the puncture portion 33 of the tubular member 30, the first slow curve portion 21a, the first sharp curve portion 21b, the second slow curve portion 21c, the second sharp curve portion 21d and the third slow curve portion 21e are protruded in the name order as shown in (b) to (e) of Fig 12. Accordingly, the needle portion 21 can be stuck into a wall portion V of a tissue P easily and the needle portion 21 stuck into the wall portion V can be prevented from being dropped out in the same manner as in the fourth embodiment.

[0098] Fig. 13 shows a sixth embodiment of the suturing instrument according to the invention. Parts substantially the same as those in the aforementioned embodiment are referred to by the same numerals and description thereof will be omitted.

[0099) The suturing instrument I Oe in this embodiment differs from that in the aforementioned embodiment in the shape given to the needle portion 21. That is, as shown in (a) of Fig. 13, the needle portion 21 of the suturing instrument lOe has a first slow curve portion 21a, a first sharp curve portion 21 b, a second slow curve portion - 21c, a second sharp curve portion 21d, and a third slow curve portion 21e.

[01001 According to this embodiment, when the needle portion 21 is pushed out of the inner circumference of the puncture portion 33 of the tubular member 30, the respective curve portions 21a, 21b, 21c, 21 d arid 21e are protruded in the named order as shown in (b) to (e) of Fig. 13 in the same maimer as in the fifth embodiment.

[0101) Fig. 14 shows a seventh embodiment of the suturing instrument according to the invention. Parts substantially the same as those in the aforementioned embodiment are referred to by the same numerals and description thereof will be omitted.

[0102] The suturing instrument 1 Of in this embodiment differs from that in the aforementioned embodiment in the shape given to the needle portion 21. That is, as shown in (a) of Fig. 14, the needle portion 21 of the suturing instrument lOf has a first slow curve portion 21a, a first sharp curve portion 21b, and a second slow curve portion 21c. When the needle portion 21 is pushed out of the puncture portion 33 of the tubular member 30, the respective curve portions 21 a, 21 b and 21 c are protruded in the named order as shown in (b) to (e) of Fig. 14.

[0103] Fig. 15 shows an eighth embodiment of the suturing instrument according to the invention. Parts substantially the same as those in the aforementioned embodiment are referred to by the same numerals and description thereof will be omitted.

[0104) V/bile the needle portion 21 of the suture needle in each of the first to seventh embodiments is made of flat wire, the needle portion 21 in the suturing instrument lOg is made of triangular wire which is triangular in sectional view (see (a) and (b) of Fig. 15). The needle portion 21 of the suturing instrument I Og is given a shape so that one flat surface side of the triangular wire is curved outward. The triangular wire fanning the needle portion 21 is formed into a shape which is thick on the base end side but tapered toward the front end 22a, so that the triangular wire can be stuck into a wall portion V of a tissue P easily.

[0105] In this embodiment, because the needle portion 21 is made of triangular wire which is triangular in sectional view, the flat surface portion of the triangular wire hardly comes into contact with the inner circumference of the tubular member 30 when.

the suture needle 20 is contained in the tubular member 30 or when the suture needle is protruded from the inner circumference of the puncture portion 33 of the tubular member 30. That is, because two corner portions of the triangular wire forming the needle portion 21 come in contact with the inner circumference of the tubular member 30, sliding resistance of the needle portion 21 to the inner circumference of the tubular member 30 becomes so small that the suture needle 20 can be moved smoothly.

[0106] In the case of the suture needle 20 of the suturing instrument lOg shown in (a) of Fig. 15, the needle portion 21 is made of continuous triangular wire which is triangular in sectional view but the needle portion 21 is not limited thereto. For example, as shown in (c) of Fig. 15, the front end portion side of the needle portion 21 may be made of triangular wire which is tnangular in sectional view but the base end portion side of the needle portion 21 may be made of round wire which is circular in sectional view. According to this, because the base end side of the needle portion 21 is made of round wire having a larger sectional area than that of the triangular wire on the front end side, rigidity on the base end side can be improved so that the base end side of the needle portion 21 can be stuck into a wall portion V of a tissue P easily.

[0107] Fig. 16 shows a ninth embodiment of the suturing instrument according to the invention. Parts substantially the same as those in the aforementioned embodiment are referred to by the same numerals and description thereof will be omitted.

(0108] In the suturing instrument lOh in this embodiment a high-frequency current can be additionally provided like a so-called high-frequency electric knife.

Specifically, as shown in Fig. 16, a tubular wall Sib is erected on the outer circumference of the tubular iiember operating portion 53 and an electrode A electrically connected to the tubular member 30 is protruded from an opening at the front end of the tubular wall Sib. A tubular wail 55a is erected on the outer circumference of the suture needle operating portion 55 and an electrode B electrically connected to the suture needle 20 is protruded from an opening at the front end of the tubular wall SSa.. The electrodes A and B are connected, through conducting wir; to a not-shown high-frequency oscillator connected to the living body. A high-frequency current can be selectively added to each of the suture needle 20 and the tubular member 30 by the high-frequency oscillator.

[0109] An insulating process is applied to the suture needle 20 aridlor the tubular member 30 to prevent short-circuiting from being caused by contact between the suture needle 20 and the tubular member 30. For example, an insulting coating made of fluorocarbon resin or the like may be applied on the inner circumference of the tubular member 30, a region of the needle portion 21 of the suture needle 20 other than the front end portion 22 may be coated with a beat-shrinkable tube made of a synthetic resin or another resin tube than the tubular member 30 and the suture needle 20 may be disposed between the tubular member 30 and the suture needle 20. An insulating unit can be determined suit&bly.

[0110] For use of the suturing instrument Oh, first, one of conducting wires extended from the not-shown high-frequency oscillator is connected to the human body and the other of the conducting wires is connected to the electrodes A and B of the suturing instrument 1 Ob ioiiii As shown in (a) of Fig. 7, for sticking the tubular member 30 into a predetermined position of a wall portion V, the tubular member 30 Is electrified from the high-frequency oscillator through the electrode A so that a high-frequency current is applied to the puncture tube 31 at the front end of the tubular member 30. As a result, Joule heat is produced in the puncture tube 31 so that the pierced wall portion V is heated instantaneously to cause protein degradation in the puncture portion.

Accordingly, the puncture tube 31 can be pushed in smoothly, so that puncturing property can be improved. In addition, blood around the puncture portion is coagulated so rapidly that the hemostatic effect can be enhanced.

[0112] To protrudethe needle portion 21 of the suture needle 20 from the puncture tube 31 of the tubular member 30 as shown in (b) and (c) of Fig. 7 from the aforementioned state, current conduction to the electrode A is stopped and the suture needle 20 is electrified through the electrode B to apply a high-frequency cun-ent to the needle portion 21 at the front end of the suture needle 20. As a result, Joule heat is produced in the needle portion 21 in the same manner as in the puncture tube 31.

Accordingly, the needle portion 21 can be pushed in smoothly, so that puncturing property can be improved while the hemostatic effect can be enhanced.

Description of Reference Numerals and Signs 3B [0113

10, 10; lOb, 10c lOd, 10; lOf, lOg, lOh suturing instrument suture needle 21 needle portion 22 front end portion.

22a front end 23 needle's eye 24 linear portion 27 connection portion 28, 28a operationwire tubular member 31 puncture tube 33 puncture portion 35, 35a operation tube 37 slit transfer tube