Patent Publication Number: US-2023149017-A1

Title: Endoscopic suturing method and medical instrument

Description:
RELATED APPLICATION DATA 
     This application is based upon and claims the benefit of priority from U.S. Provisional Patent Application Ser. No. 63/279,703, filed on Nov. 16, 2021, the entire contents of which are incorporated herein by reference. 
    
    
     FIELD OF THE DISCLOSURE 
     The present disclosure relates to an endoscopic suturing method and a medical instrument used in the endoscopic suturing method. 
     BACKGROUND 
     In endoscopic treatment, medical instruments such as clip units to treat living tissue are used. These medical instruments are introduced to the treatment site by a device that can be passed through a channel of the endoscope. 
     Japanese Unexamined Patent Application, First Publication No. H9-38093 (Patent Document 1) describes a treatment tool used to puncture a living tissue. The treatment instrument described in Patent Document 1 can be left in the body in a state of being punctured into living tissue. 
     SUMMARY 
     Based on the above circumstances, the object of the present disclosure is to provide an optimal medical instrument for suturing tissue and an endoscopic suturing method using the medical instrument. 
     The endoscopic suturing method according to the first aspect of the present invention includes penetrating an indwelling member into a first portion of a mucous membrane, moving the indwelling member toward a second portion of the mucous membrane while pushing the first portion of the mucous membrane and penetrating the indwelling member into the second portion of the mucous membrane with the indwelling member penetrated into the first portion of the mucous membrane, and leaving the indwelling member in a body in a state in which the indwelling member penetrates the first portion of the mucous membrane and the second portion of the mucous membrane. 
     The medical instrument of the present invention and the endoscopic suturing method using the medical instrument can suitably perform, for example, suturing of resected or defective portion. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a perspective view of an applicator. 
         FIG.  2    is a perspective view of the medical instrument according to a first embodiment. 
         FIG.  3    is a diagram for explaining the operation of the medical instrument. 
         FIG.  4    is a diagram for explaining the operation of the medical instrument. 
         FIG.  5    is a diagram for explaining the operation of the medical instrument. 
         FIG.  6    is a diagram for explaining the operation of the medical instrument. 
         FIG.  7    is a diagram for explaining the operation of the medical instrument. 
         FIG.  8    is a flow chart showing a suturing procedure using the medical instrument. 
         FIG.  9    is a diagram for explaining the first step of the suture treatment. 
         FIG.  10    is a cross-sectional view of the defective portion in the suturing direction. 
         FIG.  11    is a diagram for explaining the second step of the suture treatment. 
         FIG.  12    is a cross-sectional view of the missing portion in the second step. 
         FIG.  13    is a cross-sectional view of the missing portion in the second step. 
         FIG.  14    is a diagram for explaining the third step of the suture treatment. 
         FIG.  15    is a cross-sectional view of the missing portion in the third step. 
         FIG.  16    is a diagram for explaining the fourth step of the suture treatment. 
         FIG.  17    is a perspective view of a clip unit. 
         FIG.  18    is a flow chart showing a suturing procedure according to a second embodiment. 
         FIG.  19    is a flow chart showing the procedure of the fifth step of the suturing treatment. 
         FIG.  20    is a diagram for explaining the fifth step of the suture treatment. 
         FIG.  21    is a cross-sectional view of the distal end of a sheath used for suturing treatment according to a third embodiment. 
         FIG.  22    is a flow chart showing the procedure of the suture treatment. 
         FIG.  23    is a diagram for explaining the first auxiliary step of the suture treatment. 
         FIG.  24    is a diagram for explaining the first auxiliary step of the suture treatment. 
         FIG.  25    is a diagram showing a modification of the projection of the applicator. 
         FIG.  26    is a perspective view of a medical instrument according to a fourth embodiment. 
         FIG.  27    is a perspective view of a medical instrument according to another aspect of the fourth embodiment. 
         FIG.  28    is a perspective view of a medical instrument according to another aspect of the fourth embodiment. 
         FIG.  29    is a diagram for explaining treatment with the medical instrument. 
         FIG.  30    is a diagram for explaining treatment with the medical instrument. 
         FIG.  31    is a perspective view of a medical instrument according to another aspect of the same embodiment. 
         FIG.  32    is a perspective view of a medical instrument according to another aspect of the same embodiment. 
         FIG.  33    is a diagram for explaining a suturing treatment according to another aspect of the same embodiment. 
         FIG.  34    is a diagram for explaining a suturing treatment according to another aspect of the same embodiment. 
         FIG.  35    is a diagram for explaining a suturing treatment according to another aspect of the same embodiment. 
         FIG.  36    is a diagram showing a medical instrument according to a fifth embodiment. 
         FIG.  37    is a diagram showing the medical instrument. 
         FIG.  38    shows the medical instrument further including a stopper. 
         FIG.  39    shows the medical instrument further including a stopper. 
         FIG.  40    is a flow chart showing a suturing procedure using a medical instrument according to a sixth embodiment. 
         FIG.  41    is a perspective view of an applicator according to a seventh embodiment. 
         FIG.  42 A  is a side view of the hook of the applicator. 
         FIG.  42 B  is a front view of the hook viewed from direction B in  FIG.  42 A . 
         FIG.  42 C  is a cross-sectional view of the hook along line C-C in  FIG.  42 A . 
         FIG.  42 D  is a cross-sectional view of the hook along line D-D in  FIG.  42 A . 
         FIG.  43    is a perspective view of a medical instrument according to a seventh embodiment. 
         FIG.  44    is a diagram for explaining the operation of the medical instrument and the applicator. 
         FIG.  45 A  is a diagram for explaining the operation of the medical device and the applicator. 
         FIG.  45 B  is a front view of the hook viewed from direction B in  FIG.  45 A . 
         FIG.  45 C  is a cross-sectional view of the hook taken along line C-C in  FIG.  45 A . 
         FIG.  45 D  is a cross-sectional view of the hook taken along line D-D in  FIG.  45 A . 
         FIG.  46    is a diagram for explaining the operation of the medical instrument and the applicator. 
     
    
    
     DETAILED DESCRIPTION 
     First Embodiment 
     A first embodiment of the present disclosure will be described with reference to  FIGS.  1  to  17   . 
     A medical instrument  100  according to this embodiment is loaded into an applicator  200  that can be inserted through a channel of an endoscope  300  (see  FIG.  9   ) and introduced to a treatment position. 
     [Applicator  200 ] 
       FIG.  1    is a perspective view of the applicator  200 . 
     The applicator (medical instrument introduction device)  200  includes a sheath  220 , an operation wire  230  and an operation portion  240 . The applicator  200  is inserted through, for example, a treatment instrument insertion channel of the endoscope  300  and used in combination with the endoscope  300 . Therefore, the sheath  220  is formed sufficiently longer than the treatment instrument insertion channel of the endoscope  300 . The sheath  220  is flexible and curves according to the curvature of the insertion portion of the endoscope  300 . 
     The sheath  220  includes a distal tip  221 , a distal coil  222 , and a proximal coil  224 , and is formed in an elongated tubular shape as a whole. The distal coil  222  is arranged on the distal side of the sheath  220 . The distal tip  221  is arranged at the distal end of the distal coil  222 . 
     As shown in  FIG.  1   , the operation wire (power transmission member)  230  includes an arrowhead hook portion (connecting portion)  231  connected to the medical instrument  100  and a wire  232  for operating the arrowhead hook portion  231 . 
     The arrowhead hook portion  231  includes a substantially conical engaging portion  231   a  that engages with the medical instrument  100 , and a wire connecting portion  231   b  provided at the proximal end of the engaging portion  231   a . The arrowhead hook portion  231  is made of, for example, a metal material such as stainless steel. 
     The wire  232  is inserted through the sheath  220  so as to be capable of being moved back and forth. The distal end of the wire  232  is fixed to the proximal end of the wire connecting portion  231   b  by welding, for example. 
     The operation portion  240  includes an operation portion main body  241 , a slider  242 , and a thumb ring  248 , as shown in  FIG.  1   . The operation portion main body  241  is injection-molded, for example, from a resin material. The operation portion main body  241  includes a slit portion  241   a  and a rotary grip  241   b  on the distal end side. The slit portion  241   a  supports the slider  242  so as to be capable of being advanced and retracted. 
     The slider  242  is attached so as to be capable of being moved back and forth in the longitudinal axis direction of the operation portion main body  241 , and the proximal end of the wire  232  is attached. As the slider  242  is advanced and retracted along the operation portion main body  241 , the wire  232  is advanced and retracted with respect to the sheath  220 , and the arrowhead hook portion  231  is advanced and retracted. 
     The thumb ring  248  is attached to the proximal end of the operation portion main body  241  so as to be capable of being rotated around the longitudinal axis of the operation portion main body  241 . 
     [Medical Instrument  100 ] 
       FIG.  2    is a perspective view of the medical instrument  100  according to this embodiment. 
     The medical instrument  100  includes an indwelling member  1  and a connecting member  2 . The medical instrument  100  has a symmetrical shape with respect to the central axis O 1  in the longitudinal direction A of the medical instrument  100 . 
     In the following description, the side of the indwelling member  1  in the longitudinal direction A of the medical instrument  100  is referred to as the distal end side (distal side) A 1  of the medical instrument  100 , and the side of the connecting member  2  is referred to as the proximal end side (proximal side) A 2  of the medical instrument  100 . 
     The indwelling member  1  is formed in an arrowhead shape on the distal end side A 1 , and is a member that is punctured into living tissue by suturing. The indwelling member  1  includes a puncture portion  11 , a rod-shaped portion  14 , and a main body portion  15 . The indwelling member  1  is made of a biocompatible material, such as stainless steel. The indwelling member  1  may be made of a bioabsorbable material. 
     The puncture portion  11  is provided on the distal end side A 1  of the indwelling member  1  and is formed in a substantially conical shape. The puncture portion  11  has a sharp end portion  12  and a return portion  13 . The distal end portion  12  is provided on the distal end side A 1  of the puncture portion  11  and has a sharp distal end. The return portion  13  is provided on the proximal end side A 2  of the puncture portion  11  and has the largest outer diameter in the puncture portion  11 . 
     The rod-shaped portion  14  is formed in a cylindrical shape extending in the longitudinal direction A. The rod-shaped portion  14  is connected to the puncture portion  11  on the distal end side A 1 , and is connected to the main body portion  15  on the proximal end side A 2 . The outer diameter of the return portion  13  is larger than the outer diameter of the rod-shaped portion  14 . That is, the outer diameter of the puncture portion  11  is larger than the outer diameter of rod-shaped portion  14  at the connecting portion between the puncture portion  11  and the rod-shaped portion  14 . 
     The main body portion  15  is formed in a cylindrical shape extending in the longitudinal direction A. The main body portion  15  has an enlarged diameter portion  16 , an engaging portion  17 , and a connecting portion  18  connected to the connecting member  2 . 
     The enlarged diameter portion  16  is provided on the distal end side A 1  of the main body portion  15  and connected to the rod-shaped portion  14 . The enlarged diameter portion  16  is formed in a planar shape in which the distal end side A 1  is substantially perpendicular to the longitudinal direction A. The outer diameter of the enlarged diameter portion  16  is larger than the outer diameter of the rod-shaped portion  14 . That is, the outer diameter of the main body portion  15  is larger than the outer diameter of the rod-shaped portion  14  at the connecting portion between the main body portion  15  and the rod-shaped portion  14 . 
     For example, the length of the puncture portion  11  in the longitudinal direction A is approximately 5 mm. In addition, the length of the rod-shaped portion  14  in the longitudinal direction A (the length between the return portion  13  of the puncture portion  11  and the enlarged diameter portion  16  of the main body portion  15 ) is smaller than the spread width of a general clip, for example, about 10 mm. 
     The engaging portion  17  is a convex portion that protrudes from the outer peripheral surface  15   a  of the main body portion  15 . The engaging portion  17  may be a pair of protrusions provided on both sides of the main body portion  15  with the central axis O 1  interposed therebetween. The engaging portion  17  has a basic posture in which it protrudes radially outward with respect to the outer peripheral surface  15   a . The engaging portion  17  receives a radially inward force from the outer side to enter a recessed state in which the engaging portion  17  is retracted with respect to the outer peripheral surface  15   a . By releasing the above force, the engaging portion  17  returns from the recessed state to the projected state. 
     The connecting member  2  is separably connected to the connecting portion  18  of the indwelling member  1 . In addition, the connecting member  2  is detachably connected to an arrowhead hook portion  231  inserted through the sheath  220 . That is, the connecting member  2  connects the indwelling member  1  and the arrowhead hook portion  231 . The connecting member  2  has a distal connecting portion  21  and a proximal connecting portion  22 . 
     The distal connecting portion  21  is provided on the distal end side A 1  of the connecting member  2 , and the distal end portion is inserted into the internal space of the indwelling member  1  and connected to the connecting portion  18  in a separable manner. The distal connecting portion  21  is connected to the proximal connecting portion  22  on the proximal side A 2 . 
     The proximal end connecting portion  22  is detachably connected to the arrowhead hook portion  231  of the applicator  200 . The proximal connecting portion  22  is bifurcated from the distal connecting portion  21  on the proximal side A 2 . The proximal connecting portion  22  is elastically deformable with respect to the distal connecting portion  21  and is capable of being opened and closed with respect to the distal connecting portion  21 . A notch portion  22   m  is formed between the proximal end connecting portions  22  to hold and store the engaging portion  231   a  of the arrowhead hook portion  231 . The cutout portion  22   m  is formed in a shape that closely contacts the outer peripheral surface of the engaging portion  231   a  of the arrowhead hook portion  231 . 
     [Operation and Action of Medical Instrument  100 ] 
     Next, the operation of the medical instrument  100  will be described.  FIGS.  3  to  7    are diagrams for explaining the operation of the medical instrument  100 . 
     The connecting member  2  of the medical instrument  100  loaded in the applicator  200  is connected to the arrowhead hook portion  231  that passes through the sheath  220 , as shown in  FIG.  3   . The engaging portion  17  is pressed by the inner peripheral surface of the sheath  220  and is in a retracted state. 
     The operator introduces the medical instrument  100  loaded into the applicator  200  into the body through the channel of the endoscope  300 . Next, the operator advances the arrowhead hook portion  231  by advancing the slider  242  along the operation portion main body  241 . The operator advances the medical instrument  100  until the engaging portion  17  comes out of the sheath  220 . As shown in  FIG.  4   , the engaging portion  17  transitions from the retracted state to the protruding state, which is the basic posture, by coming out of the sheath  220 . 
     The engaging portion  17  in the projecting state engages with the distal tip  221  of the sheath  220  and is not pulled into the sheath  220 . Therefore, the indwelling member  1  is not pulled into the sheath  220  after coming out of the sheath  220 . 
     Next, the operator operates the endoscope  300  and the operation portion  240  to move the indwelling member  1  and puncture the living tissue T with the puncture portion  11 , as shown in  FIG.  5   . The operator advances the indwelling member  1  until the return portion  13  of the puncture portion  11  penetrates the living tissue T. Since the engaging portion  17  engages with the distal tip  221  of the sheath  220 , the operator can easily puncture the living tissue T with the puncture portion  11 . 
     Next, the operator retracts the arrowhead hook portion  231  by retracting the slider  242  along the operation portion main body  241 . The connecting member  2  connected to the arrowhead hook portion  231  pulls the indwelling member  1 . Since the engaging portion  17  in the projecting state engages with the distal tip  221  of the sheath  220 , it is not pulled into the sheath  220 . As shown in  FIG.  6   , the distal end connecting portion  21  of the connecting member  2  is separated from the connecting portion  18  of the indwelling member  1  by, for example, partly breaking the distal end connecting portion  21 . The connecting member  2  may be separated from the connecting portion  18  of the indwelling member  1  by elastic deformation or plastic deformation of a part of the distal end connecting portion  21 , for example. 
     Next, as shown in  FIG.  7   , the operator retracts the endoscope  300  and the sheath  220 , and indwells the indwelling member  1  that has punctured the living tissue T inside the body. In the indwelled indwelling member  1 , the rod-shaped portion  14  sandwiched between the return portion  13  and the enlarged diameter portion  16  penetrates the living tissue T. The living tissue T is sandwiched between the return portion  13  and the enlarged diameter portion  16  that function to prevent coming off, and the indwelling member  1  does not come off from the living tissue T. 
     [Suture treatment using medical instrument  100 ] 
     Next, suturing treatment using the medical instrument  100  will be described. Specifically, a treatment for suturing a defective portion D (diseased portion) formed in the body by endoscopic treatment will be described.  FIG.  8    is a flow chart showing the suturing procedure. 
     &lt;First Step S 1 &gt; 
       FIG.  9    is a diagram for explaining the first step S 1  of suturing treatment. 
     First, the operator brings the indwelling member  1  closer to the defective portion D (first step S 1 ). Henceforth, the content of the first step S 1  is demonstrated concretely. 
       FIG.  10    is a cross-sectional view of the defective portion D in the suturing direction S. 
     The operator brings the endoscope  300  closer to the defective portion D. The operator observes the defective portion D and determines the suturing direction S in which the defective portion D is sutured based on the size and shape of the defective portion D. In the following description, the mucous membranes surrounding the defective portion D and arranged facing each other in the suturing direction S across the defective portion D are referred to as “first mucosa M 1 ” and “second mucosa M 2 ”. 
     The operator introduces the medical instrument  100  loaded into the applicator  200  into the body through the channel of the endoscope  300 . As shown in  FIG.  9   , the operator moves the endoscope  300  and the sheath  220  to bring the indwelling member  1  of the medical instrument  100  closer to the first mucous membrane M 1 . 
     &lt;Second Step S 2 &gt; 
       FIG.  11    is a diagram for explaining the second step S 2  of the suture treatment. 
     The operator penetrates the indwelling member  1  through the first mucous membrane M 1  (second step S 2 ). Henceforth, the content of the second step S 2  is demonstrated concretely. 
       FIG.  12    is a cross-sectional view of the defective portion D in the second step S 2 , showing a state before the indwelling member  1  penetrates the first mucous membrane M 1 . 
     The operator presses the distal end portion  12  of the puncture portion  11  of the indwelling member  1  against the first portion P 1  of the first mucous membrane M 1  where the defective portion D has a large width in the suturing direction S. The operator creates a region where the puncture portion  11  of the indwelling member  1  can be easily punctured by pressing the distal end portion  12  against the first portion P 1 . At this time, the operator presses the indwelling member  1  against the mucous membrane M with the first strength. For example, the operator raises the first portion P 1  as shown in  FIG.  12   . The operator may perform other treatments in order to create a region where the puncture portion  11  can be easily punctured. It should be noted that the operator may omit the treatment for creating the easy-puncture region if unnecessary. 
       FIG.  13    is a cross-sectional view of the missing portion D in  FIG.  11   . 
     The operator causes the indwelling member  1  to penetrate through the first portion P 1  of the first mucous membrane M 1  where the width of the defective portion D in the suturing direction S is large. Specifically, as shown in  FIG.  11   , the operator pierces the first portion P 1  with the puncture portion  11  of the indwelling member  1  from the outside to the inside of the defective portion D, and pushes the indwelling member  1  until the puncture portion  11  of the indwelling member  1  penetrates the first portion P 1 . At this time, the operator pushes the indwelling member  1  with a second strength that is greater than the first strength. 
     &lt;Third Step S 3 &gt; 
       FIG.  14    is a diagram for explaining the third step S 3  of suturing treatment. 
     The operator penetrates the indwelling member  1  through the second mucous membrane M 2  (third step S 3 ). Henceforth, the content of the third step S 3  is demonstrated concretely. 
       FIG.  15    is a cross-sectional view of the defective portion D in the third step S 3 , showing the state before the indwelling member  1  penetrates the second mucous membrane M 2 . 
     The operator presses the distal end portion  12  of the puncture portion  11  of the indwelling member  1  against the second portion P 2  of the second mucous membrane M 2  where the defective portion D has a large width in the suturing direction S. The operator creates a region where the puncture portion  11  of the indwelling member  1  can be easily punctured by pressing the distal end portion  12  against the second portion P 2 . For example, the operator raises the second portion P 2  as shown in  FIG.  15   . The operator may perform other treatments in order to create a region where the puncture portion  11  can be easily punctured. It should be noted that the operator may omit the treatment for creating the easy-puncture region if unnecessary. 
     The operator causes the indwelling member  1  to penetrate through the second portion P 2  of the second mucous membrane M 2  where the width of the defective portion D in the suturing direction S is large. Specifically, as shown in  FIG.  14   , the operator pierces the puncture portion  11  of the indwelling member  1  from the inside to the outside of the defective portion D to the second portion P 2 , and pushes the indwelling member  1  until the puncture portion  11  of the indwelling member  1  penetrates the second portion P 2 . 
     As shown in  FIG.  14   , in the indwelling member  1 , the rod-shaped portion  14  sandwiched between the return portion  13  and the enlarged diameter portion  16  passes through the first portion P 1  and the second portion P 2 . Therefore, the first portion P 1  through which the indwelling member  1  penetrates cannot move toward the proximal side A 2  from the enlarged diameter portion  16 , and the second portion P 2  through which the indwelling member  1  penetrates cannot move toward the distal side A 1  from the return portion  13 . Therefore, the first portion P 1  and the second portion P 2  through which the indwelling member  1  penetrates are arranged in the range between the return portion  13  and the enlarged diameter portion  16 , and are arranged at positions closer to each other than before the treatment. The distance between the first portion P 1  and the second portion P 2  in the direction in which the indwelling member  1  extends (longitudinal direction A) becomes smaller than before the treatment. 
     From the viewpoint of suture treatment of a large defective portion D in a small number of treatment steps, it is desirable that the first portion P 1  and the second portion P 2  be portions where the width of the defective portion D in the suturing direction S is the largest. 
     The first portion P 1  engages with the expanded diameter portion  16  to return to the proximal end side A 2 . The second portion P 2  engages with the return portion  13  to return to the distal end side A 1 . Therefore, a gap C is formed between the first portion P 1  and the second portion P 2 . However, if the length of the portion through which the indwelling member  1  penetrates at the first portion P 1  and the second portion P 2  is long, the gap C may not be formed. 
     &lt;Fourth Step S 4 &gt; 
       FIG.  16    is a diagram for explaining the fourth step S 4  of the suture treatment. 
     The operator indwells the indwelling member  1  (fourth step S 4 ). Henceforth, specific contents of the fourth step S 4  will be described. 
     The operator pulls the connecting member  2  to the proximal side A 2 . The distal end connecting portion  21  of the connecting member  2  is separated from the connecting portion  18  of the indwelling member  1  by, for example, part of the distal end connecting portion  21  being broken or deformed. The operator withdraws the endoscope  300  and the sheath  220  to leave the indwelling member  1  in the body, which has passed through the first portion P 1  and the second portion P 2 . 
     The operator pulls out the applicator  200  from the channel of the endoscope  300  to finish the suture treatment. The return portion  13  and the diameter-enlarged portion  16  functioning as slip-off prevention sandwich the first portion P 1  and the second portion P 2 , and the indwelled indwelling member  1  does not slip out from the first portion P 1  and the second portion P 2 . 
     According to the suturing treatment using the medical instrument  100  according to this embodiment, the treatment of suturing the defective portion D can be performed only by puncturing the indwelling member  1  into the first mucous membrane M 1  and the second mucous membrane M 2 . Even if the defective portion D is large, which is difficult to suture with a clip, the defective portion D can be sutured in approximately one treatment. Therefore, suture treatment using the medical instrument  100  takes less time to suture a large defective portion D than suture treatment using a clip, stapler, or suture needle. 
     According to the suturing treatment using the medical instrument  100  according to this embodiment, it is sufficient to push the indwelling member  1  in the imaging direction, which is the longitudinal axis direction of the endoscope  300 . Therefore, it is easy to adjust the position and attitude of the endoscope  300  (angle operation, etc.) so that the defective portion D, which is the treatment position, is within the field of view of the endoscope  300 . 
     As described above, the first embodiment of the present disclosure has been described in detail with reference to the drawings, but the specific configuration is not limited to this embodiment, and design changes and the like are included within the scope of the present disclosure. Also, the constituent elements shown in the above-described embodiment and modifications shown below can be combined as appropriate. 
     Second Embodiment 
     A second embodiment of the present disclosure will be described with reference to  FIGS.  17  to  20   . In the following description, the same reference numerals are given to the same configurations as those already described, and redundant descriptions will be omitted. The suturing treatment using the medical instrument  100  according to the second embodiment uses the clip unit  400  in addition to the medical instrument  100 . 
     [Clip Unit  400 ] 
       FIG.  17    is a perspective view of the clip unit  400 . 
     The clip unit  400  is a known clip unit. Such a clip unit is disclosed in PCT International Publication No. WO 2021/172544, the entire text of which is incorporated herein by reference. The clip unit  400  includes, for example, a clip  3 , a holding tube  4  as a tightening member, and a connecting member  5 . 
     The clip (second indwelling member)  3  is formed by bending a metal plate material such as a leaf spring material made of stainless steel or the like at the center. The clip  3  has a pair of arms  31  that can be opened and closed in the opening and closing direction P, and a connecting portion  32  that connects the pair of arms  31 . 
     The hold-down tube  4  has a hold-down tube main body  40  formed in a cylindrical shape and an engaging portion  41 . The engaging portion  41  has the same function as the engaging portion  17  of the medical instrument  100 . 
     The connecting member  5  is connected to the connecting portion  32  of the clip  3 . In addition, the connecting member  5  is connected to the arrowhead hook portion  231  passing through the sheath  220  in the same manner as the connecting member  2  of the medical instrument  100 . That is, the connecting member  5  connects the clip  3  and the arrowhead hook portion  231 . The connecting member  5  has a distal connecting portion  51  inserted into the inner space of the pressing tube  4  and a proximal connecting portion  52  provided at the proximal end of the distal connecting portion  51 . 
     The proximal connecting portion  52  is detachably connected to the arrowhead hook portion  231  of the applicator  200  in the same manner as the proximal connecting portion  22  of the medical instrument  100 . 
     [Suture Treatment Using Medical Instrument  100 ] 
     Next, suture treatment using the medical instrument  100  and the clip unit  400  will be described.  FIG.  18    is a flow chart showing the suturing procedure. The first step S 1  to the fourth step S 4  in the suture treatment according to this embodiment are the same as in the first embodiment. The suturing treatment according to this embodiment further includes a fifth step S 5 . 
     &lt;Fifth Step S 5 &gt; 
       FIG.  19    is a flow chart showing the procedure of the fifth step S 5 . 
     After the fourth step S 4 , the operator determines whether or not there is a portion of the defective portion D in which the width in the suturing direction S is so large that it cannot be sutured with the medical clip  3 , except for the sites (the first portion P 1  and the second portion P 2 ) where the suturing treatment is performed using the indwelling member  1  of the medical instrument  100  (step S 51 ). 
     If there is a portion that cannot be sutured with the clip  3 , the operator sutures the portion using the medical instrument  100  in the same manner as in the first embodiment (step S 52 ). The length of the rod-shaped portion  14  of the medical instrument  100  in the longitudinal direction A (the length between the return portion  13  of the puncture portion  11  and the enlarged diameter portion  16  of the main body portion  15 ) is shorter than the maximum opening width of the pair of arms  31  of the clip  3 . Therefore, by using the indwelling member  1  of the medical instrument  100  to reduce the width of the defective portion D in the suturing direction S, the operator can easily perform suturing treatment by using the pair of arms  31  of the clip  3  at portions other than the sutured portion using the indwelling member  1  of the medical instrument  100 . The operator punctures the mucous membrane surrounding the defective portion D with the second medical instrument  100  (indwelling member  1 ) in the same direction as the first medical instrument  100  (indwelling member  1 ) has been punctured. As a result, the operator can puncture the mucous membrane surrounding the defective portion D with the second medical instrument  100  (indwelling member  1 ) without significantly changing the position and bending angle of the distal end of the endoscope  300 . 
     A portion of the first mucous membrane M 1  other than the first portion P 1  is referred to as a “third portion P 3 ”. Also, a portion of the second mucous membrane M 2  other than the second portion P 2  and facing the third portion P 3  in the suturing direction S is referred to as a “fourth portion P 4 ”. When the length between the third portion P 3  and the fourth portion P 4  is longer than the length that can be sutured by the clip  3 , the operator penetrates the second indwelling member  1  through the third portion P 3  and the fourth portion P 4  to be indwelled. 
     If there is no third portion P 3  or fourth portion P 4  such that the length between the third portion P 3  and the fourth portion P 4  is longer than the length that can be sutured by the clip  3 , the operator  3  determines whether there is a portion to be sutured (step S 53 ). 
       FIG.  20    is a diagram for explaining the fifth step S 5  of the suturing treatment. 
     When there is a portion to be sutured using the clip  3 , the operator sutures the portion using the clip unit  400  by a known method, as shown in  FIG.  20    (step S 54 ). When the length between the third portion P 3  and the fourth portion P 4  is a length that can be sutured with the clip  3 , the operator grasps the third portion P 3  and the fourth portion P 4  with the clip  3  and pulls them together, and indwells the clip  3  there. 
     According to the suturing treatment using the medical instrument  100  and the clip unit  400  according to this embodiment, by using different treatment tools (the medical instrument  100  and the clip unit  400 ) based on the width of the defective portion D in the suturing direction S, the suturing treatment of suturing a plurality of sites can be performed more appropriately. 
     As described above, the second embodiment of the present disclosure has been described in detail with reference to the drawings, but the specific configuration is not limited to this embodiment, and design changes and the like are also included within the scope of the present disclosure. Also, the constituent elements shown in the above-described embodiment and modifications shown below can be combined as appropriate. 
     (Modification) 
     In the above embodiment, the clip  3  is used as the second indwelling member in the fifth step S 5 , but the fifth step S 5  is not limited to suture treatment using the clip  3 . The fifth step S 5  may be suturing using a thread as the second indwelling member and suturing with a thread and a needle. 
     Third Embodiment 
     A third embodiment of the present disclosure will be described with reference to  FIGS.  21  to  25   . In the following description, the same reference numerals are given to the same configurations as those already described, and redundant descriptions will be omitted. The suturing treatment using the medical instrument  100  according to the third embodiment uses an applicator  200 B that is a modification of the applicator  200 . 
     [Applicator  200 B] 
     The applicator  200 B differs from the applicator  200  of the first embodiment in that the sheath has a double structure. The applicator  200 B includes a sheath  220 B, an outer sheath  250 , an operation wire  230 , and an operation portion  240 . 
       FIG.  21    is a cross-sectional view of the distal end of the sheath  220 B. 
     The sheath (inner sheath)  220 B is a coil sheath similar to the sheath  220  of the first embodiment. A distal tip  221  at the distal end of the sheath  220 B is provided with a projection  260  facing radially outward. The protrusions  260  may be protrusions provided at two portions facing each other in the radial direction, or may be protrusions provided along the entire circumference in the circumferential direction. 
     The outer sheath  250  is a sheath provided on the outer peripheral side of the sheath  220 B. The sheath  220 B and the outer sheath  250  can be advanced and retracted independently by the operation portion  240 . 
     [Suture Treatment Using Medical Instrument  100  and Applicator  200 B] 
     Next, suture treatment using the medical instrument  100  and the applicator  200 B will be described.  FIG.  22    is a flow chart showing the suturing procedure. The first step S 1  to the fourth step S 4  in the suture treatment according to this embodiment are the same as in the first embodiment. The suturing treatment according to this embodiment further includes a first auxiliary step of fixing the periphery of the first portion P 1  before the second step S 2 , and a second auxiliary step of fixing the periphery of the second portion P 2  before the third step S 3 . 
     &lt;First Auxiliary Step S 6 &gt; 
       FIGS.  23  and  24    are diagrams for explaining the first auxiliary step S 6 . 
     Before the second step S 2 , the operator fixes the first mucous membrane M 1  around the first portion P 1  (first auxiliary step S 6 ). Specifically, as shown in  FIG.  23   , the operator advances the sheath  220 B and presses it against the first mucous membrane M 1  around the first portion P 1 . Next, the operator advances the outer sheath  250  to sandwich the first mucous membrane M 1  between the sheath  220 B and the outer sheath  250 . Since the projection  260  is hooked on the first mucous membrane M 1 , the operator can easily sandwich the first mucous membrane M 1  between the sheath  220 B and the outer sheath  250 . 
     Next, as shown in  FIG.  24   , the operator causes the indwelling member  1  to penetrate through the first portion P 1  (second step S 2 ). Since the first mucous membrane M 1  is sandwiched and fixed between the sheath  220 B and the outer sheath  250 , the operator can easily puncture the first portion P 1  with the puncture portion  11  of the indwelling member  1 . 
     &lt;Second Auxiliary Step S 7 &gt; 
     The second auxiliary step S 7  is the same as the first auxiliary step S 6  except that the treatment is performed not at the second portion P 1  but at the second portion P 2 . 
     According to the suturing treatment using the medical instrument  100  and the applicator  200 B according to this embodiment, the puncture portion  11  of the indwelling member  1  can easily puncture the first portion P 1  and the second portion P 2 . 
     As described above, the third embodiment of the present disclosure has been described in detail with reference to the drawings, but the specific configuration is not limited to this embodiment, and design changes and the like are included within the scope of the present disclosure. Also, the constituent elements shown in the above-described embodiment and modifications shown below can be combined as appropriate. 
     (Modification) 
     For example, in the above embodiment, the protrusion  260  faces radially outward. However, the aspect of the protrusions provided on the sheath  220 B is not limited to this.  FIG.  25    shows a projection  260 B that is a modified example of projection  260 . The protrusion  260 B is provided so as to face the distal end side. The protrusions  260 B may be protrusions provided at two portions facing each other in the radial direction, or may be protrusions provided along the entire circumference in the circumferential direction. In this case, the outer sheath  250  is not necessarily required. 
     Fourth Embodiment 
     A fourth embodiment of the present disclosure will be described with reference to  FIGS.  26  to  35   . In the following description, the same reference numerals are given to the same configurations as those already described, and redundant descriptions will be omitted. Compared with the medical instrument  100  of the first embodiment, the medical instrument  100 C and the like according to the fourth embodiment are easier to remove the indwelling member  1  that has punctured the mucous membrane and to re-insert the indwelling member  1 . 
       FIG.  26    is a perspective view of a medical instrument  100 C according to this embodiment. 
     The medical instrument  100 C includes a puncture portion  11 C that is a modification of the puncture portion  11 . The puncture portion  11 C has a sharp distal end portion  12  with a sharp distal end and a return portion  13 C. The return portion  13 C is formed in the shape roundish compared with the return portion  13  of the first embodiment. Therefore, when moving the medical instrument  100 C that has punctured the mucous membrane to the proximal end side, the puncture portion  11 C is more likely to come off the mucous membrane than the puncture portion  11  of the first embodiment. 
       FIG.  27    is a perspective view of a medical instrument  100 D according to another aspect of this embodiment. 
     The medical instrument  100 D includes a puncture portion  11 D that is a modification of the puncture portion  11 . The puncture portion  11 D has a sharp distal end portion  12  with a sharp distal end and a return portion  13 D. The return portion  13 D is formed in a disc shape by an elastic member. Since the return portion  13 D is elastically deformable, when the medical instrument  100 D that has punctured the mucous membrane is moved to the proximal end side, the puncture portion  11 D is more easily removed from the mucous membrane than the puncture portion  11  of the first embodiment. 
       FIG.  28    is a perspective view of a medical instrument  100 E according to another aspect of this embodiment. 
     The medical instrument  100 E includes a puncture portion  11 E that is a modification of the puncture portion  11 . The puncture portion  11 E has a sharp distal end portion  12  with a sharp distal end and a return portion  13 E. The return portion  13 E is not provided over the entire circumference in the circumferential direction C, unlike the return portion  13  of the first embodiment, but is provided only partially in the circumferential direction C. 
       FIGS.  29  and  30    are diagrams for explaining treatment by using the medical instrument  100 E. 
     As shown in  FIG.  29   , the operator can move the position of the return portion  13 E by rotating the puncture portion  11 E in the circumferential direction C even after the puncture portion  11 E has penetrated the first mucous membrane M 1 . As shown in  FIG.  30   , the operator moves the return portion  13 E to a position where it can easily pass through the hole formed in the first mucosa M 1 , thereby facilitating removal of the puncture portion  11 E from the first mucosa M 1 . 
       FIG.  31    is a perspective view of a medical instrument  100 F according to another aspect of this embodiment. 
     The medical instrument  100 F includes a puncture portion  11 F that is a modification of the puncture portion  11 . The puncture portion  11 F has a sharp end portion  12  with a sharp distal end and a screw portion  13 F. The screw portion  13 F is a screw thread formed along the circumferential direction C in a screw shape. By rotating the screw portion  13 F in the circumferential direction C, the operator can easily remove the puncture portion  11 F from the mucous membrane. 
       FIG.  32    is a perspective view of a medical instrument  100 G according to another aspect of this embodiment. 
     The medical instrument  100 G includes a puncture portion  11 G that is a modification of the puncture portion  11 . The puncture portion  11 G has the same shape as the puncture portion  11  of the first embodiment, but the dimension in the longitudinal direction A is different. The puncture portion  11 G has a longer length in the longitudinal direction A than the puncture portion  11  of the first embodiment. The puncture portion  11 G has a smaller inclination angle with respect to the central axis O 1  than the puncture portion  11  of the first embodiment. Therefore, the puncture portion  11 G is more likely to come out of the mucosa than the puncture portion  11  of the first embodiment. For example, the length in the longitudinal direction A of the puncture portion  11 G is approximately 10 mm, and the length in the longitudinal direction A of the rod-shaped portion  14  is approximately 10 mm. Since the length of the puncturing portion  11 G in the longitudinal direction A is long, when the puncturing portion  11 G is punctured into the mucous membrane, it is likely that the distal end portion  12  penetrates the mucous membrane, but the return portion  13  does not penetrate the mucous membrane. The operator can easily confirm the puncture position by looking at the distal end portion  12  that has penetrated the mucous membrane. Furthermore, even when the operator changes the confirmed puncture position, the operator can easily pull out the puncture portion  11 G from the mucous membrane because the return portion  13  does not penetrate the mucous membrane. 
       FIGS.  33  to  35    are diagrams for explaining a suturing treatment according to another aspect of this embodiment. A medical instrument  100  and an applicator  200 C are used for suture treatment in this mode. 
     The applicator  200 C differs from the applicator  200  of the first embodiment in that the sheath has a double structure. The applicator  200 B includes a sheath  220 , an outer sheath  250 , an operation wire  230 , and an operation portion  240 . 
     The operator pierces the mucous membrane M with the puncture portion  11  of the indwelling member  1  as shown in  FIG.  33   . Next, the operator advances the outer sheath  250  with respect to the sheath  220  as shown in  FIG.  34   . Next, the operator retracts the indwelling member  1  as shown in  FIG.  35   . Since the mucous membrane M is engaged with the distal end of the outer sheath  250 , the operator can easily remove the puncture portion  11  from the mucous membrane M. Even if the indwelling member  1  is retracted without advancing the outer sheath  250 , since the mucous membrane M retracted together with the indwelling member  1  engages with the distal end of the outer sheath  250 , the operator can easily remove the puncture portion  11  from the mucous membrane M. 
     According to the suturing treatment using the medical instrument  100 C or the like and the applicator  200 C according to this embodiment, it is easy to remove the indwelling member  1  that has punctured the mucous membrane. Therefore, the operator can easily perform the following treatment. After penetrating the indwelling member  1  through the first portion P 1  of the first mucous membrane M 1 , the operator pulls out the indwelling member  1  from the first portion P 1  and allows the indwelling member  1  to penetrate through another portion of the first mucous membrane M 1 . Further, after penetrating the indwelling member  1  through the second portion P 2  of the second mucous membrane M 2 , the operator pulls out the indwelling member  1  from the second portion P 2  and penetrates the indwelling member  1  through another portion of the second mucous membrane M 2 . 
     As described above, the fourth embodiment of the present disclosure has been described in detail with reference to the drawings, but the specific configuration is not limited to this embodiment, and design changes and the like are included within the scope of the present disclosure. Also, the constituent elements shown in the above-described embodiment and modifications shown below can be combined as appropriate. 
     Fifth Embodiment 
     A fifth embodiment of the present disclosure will be described with reference to  FIGS.  36  to  39   . In the following description, the same reference numerals are given to the same configurations as those already described, and redundant descriptions will be omitted. The medical instrument  100 H according to the fifth embodiment includes a regulating member that regulates the amount of puncture into the mucous membrane compared to the medical instrument  100  of the first embodiment. 
       FIGS.  36  and  37    are diagrams showing a medical instrument  100 H according to this embodiment. 
     The medical instrument  100 H further includes an elastic member  6  compared to the medical instrument  100  of the first embodiment. 
     The elastic member (regulating member)  6  is formed in a cylindrical shape from an elastic material such as rubber. The elastic member  6  surrounds the outer circumference of the rod-shaped portion  14 . The distal end of the elastic member  6  engages with the return portion  13 . When the operator pushes the indwelling member  1  against the mucous membrane M, a portion of the mucous membrane M enters between the return portion  13  and the elastic member  6  by restoring the mucous membrane M in the direction of closing the hole formed in the mucous membrane M as shown in  FIG.  37   . Therefore, even if the operator tries to further push the indwelling member  1  into the mucous membrane M, the indwelling member  1  cannot be pushed out. As a result, the amount of puncturing of the mucous membrane M by the indwelling member  1  is regulated. 
     According to the suturing treatment using the medical instrument  100 H according to the present embodiment, the amount of puncturing of the mucous membrane by the indwelling member  1  can be regulated, and it is possible to prevent damage to the muscle layer or the like due to excessive puncturing of the indwelling member  1 . 
     As described above, the fifth embodiment of the present disclosure has been described in detail with reference to the drawings, but the specific configuration is not limited to this embodiment, and design changes and the like are included within the scope of the present disclosure. Also, the constituent elements shown in the above-described embodiment and modifications shown below can be combined as appropriate. 
     (Modification) 
     For example, the medical instrument  100 H may have the stopper  7  in the above embodiment.  FIGS.  38  and  39    show a medical instrument  1001  further including a stopper  7 . A stopper  7  is provided at the distal end of the elastic member  6 . When the operator pushes the indwelling member  1  of the medical instrument  1001  against the mucous membrane M, the stopper  7  is pushed by the mucous membrane M and moves to the proximal side A 2 . As shown in  FIG.  39   , the elastic member  6  is compressed by the mucous membrane pushing the stopper  7  toward the proximal end side A 2 . The elastic member  6  functions like a damper to prevent the indwelling member  1  from penetrating the mucous membrane too much. 
     Sixth Embodiment 
     A sixth embodiment of the present disclosure will be described with reference to  FIG.  40   . In the following description, the same reference numerals are given to the same configurations as those already described, and redundant descriptions will be omitted. 
     A suturing treatment using the medical instrument  100 J according to this embodiment will be described.  FIG.  40    is a flow chart showing the suturing procedure. The first step S 1  to the fourth step S 4  in the suture treatment according to this embodiment are the same as in the first embodiment. The suturing treatment according to this embodiment further includes a removing step S 8 . 
     &lt;Removal Step S 8 &gt; 
     The medical instrument  100 J further includes a fragile portion  8  that is easily destroyed by an external force or the like, compared to the medical instrument  100  of the first embodiment. The operator destroys the fragile portion  8  of the indwelled medical instrument  100 J and removes the medical instrument  100 J from the defective portion D (removal step S 8 ). 
     The fragile portion  8  has mechanical fragility, for example. The fragile portion  8  having mechanical fragility is, for example, a portion that is locally formed to be thinner than other portions, or a portion that is provided with a mechanically fragile portion by heat treatment or the like. 
     The fragile portion  8  has, for example, electrical fragility. The fragile portion  8  having electrical fragility is, for example, a portion that is locally formed to be thinner than other portions, and is a portion that is likely to break when an electric current flows from the outside. 
     The fragile portion  8  has, for example, chemical fragility. The fragile portion  8  having chemical fragility is, for example, a portion that is likely to break when exposed to body fluids. For example, when the indwelling member  1  is made of a magnesium alloy and is entirely covered with an oxide film, the fragile portion  8  having chemical fragility is a portion where the base material of magnesium is exposed by partially removing the surface of the oxide film. By increasing the exposed area of the magnesium matrix, the chemical vulnerability can be increased. 
     The fragile portion  8  is provided in the return portion  13 , for example. The fragile portion  8  may be formed in the return portion  13  by removing the oxide film of the return portion  13 . Further, the return portion  13  may be formed with a hole or a spiral groove to increase the exposed area of the magnesium base material, thereby increasing mechanical and chemical fragility. 
     When the fragile portion  8  formed in the return portion  13  is destroyed, the mucous membrane sandwiched between the return portion  13  and the enlarged diameter portion  16  can move to the distal end side A 1  from the return portion  13 . Therefore, the indwelling member  1  that has been indwelled can be easily removed from the mucous membrane. 
     The weakened portion  8  is provided, for example, on the rod-shaped portion  14 . The weakened portion  8  may be formed in the rod-shaped portion  14  by removing the oxide film of the rod-shaped portion  14 . Furthermore, by forming a hole or forming a spiral groove in the rod-shaped portion  14 , the exposed area of the magnesium base material may be increased to increase mechanical and chemical fragility. 
     When the fragile portion  8  formed in the rod-shaped portion  14  is destroyed, the indwelling member  1  is separated into two parts, the distal side including the return portion  13  and the proximal side including the enlarged diameter portion  16 . Therefore, the portion on the distal end side including the return portion  13  and the portion on the proximal end side including the enlarged diameter portion  16  are easily removed from the mucous membrane. 
     The fragile portion  8  is provided, for example, at the distal end portion  12 . The weakened portion  8  may be formed in the distal end portion  12  by removing the oxide film of the distal end portion  12 . Furthermore, a hole or a spiral groove may be formed in the sharp end  12  to increase the exposed area of the magnesium base material, thereby increasing mechanical and chemical fragility. 
     By destroying the fragile portion  8  formed in the distal end portion  12 , it is possible to prevent tissue from being unintentionally damaged by the distal end portion  12  when the indwelling member  1  remains in the body for a long period of time. 
     According to the suturing treatment using the medical instrument  100 J according to this embodiment, the indwelling member  1  that is no longer needed can be easily removed from the body. In addition, it is possible to prevent the tissue from being unintentionally damaged by the distal end portion  12 . 
     As described above, the sixth embodiment of the present disclosure has been described in detail with reference to the drawings, but the specific configuration is not limited to this embodiment, and design changes and the like are included within the scope of the present disclosure. Also, the constituent elements shown in the above-described embodiment and modifications shown below can be combined as appropriate. 
     Seventh Embodiment 
     A seventh embodiment of the present disclosure will be described with reference to  FIGS.  41  to  46   . In the following description, the reference numerals are given to the configurations as those already described, and redundant descriptions will be omitted. 
     A medical instrument  100 K according to this embodiment is loaded into an applicator  200 K that can be inserted through a channel of an endoscope  300  (see  FIG.  9   ) and introduced to a treatment position. 
     [Applicator  200 K] 
       FIG.  41    is a perspective view of the applicator  200 K. 
     The applicator (medical instrument introduction device)  200 K includes a sheath  220 , an operation wire  230 , an operation portion  240 , and a hook  270 . The applicator  200 K is inserted through, for example, a treatment instrument insertion channel of the endoscope  300  and used in combination with the endoscope  300 . 
       FIG.  42 A  is a side view of the hook  270 .  FIG.  42 B  is a front view of hook  270  viewed from direction B in  FIG.  42 A .  FIG.  42 C  is a cross-sectional view of hook  270  along line C-C in  FIG.  42 A .  FIG.  42 D  is a cross-sectional view of hook  270  along line D-D in  FIG.  42 A . 
     A hook (holding member)  270  is arranged on the distal end side of the distal tip  221 . The hook  270  includes a hook main body  271  and a hook distal end portion (restriction portion)  272 . In the following description, the side of the hook distal end portion  272  in the longitudinal direction B of the hook  270  is referred to as the distal end side (distal side) B 1  of the hook  270 , and the side of the sheath  220  is referred to as the proximal end side (proximal side) B 2  of the hook  270 . 
     The hook main body  271  is a member extending along the longitudinal direction B. The hook main body  271  may have a cross-sectional shape having a first axis (major axis) and a second axis (minor axis) shorter than the first axis in a cross section perpendicular to the longitudinal direction B. The cross-sectional shape of the hook main body  271  is, for example, elliptical, oval, or rectangular. In this case, the hook main body  271  is hard to bend in the first axial direction and easy to bend in the second axial direction. 
     The hook distal end portion  272  is provided on the distal end side B 1  of the hook main body  271 . The hook distal end portion  272  has a passageway  273  that, in cross-section perpendicular to longitudinal direction B, is larger than the outer diameter of channel  2200  of the sheath  220 . For example, the hook distal end portion  272  is formed in a substantially U shape when viewed from the longitudinal direction B. The hook distal end portion  272  may have an anchor  274 . For example, the anchor  274  is a protrusion facing the proximal end side B 2  of the hook. A plurality of anchors  274  may be provided at the hook distal end portion  272 . In addition, the anchor  274  may be a surface having a higher coefficient of friction than other portions provided on the proximal end side B 2  of the hook distal end portion  272 . 
     The hook main body  271  may be detachably connected to the sheath  220 . Specifically, the hook main body  271  of the hook  251  may be detachably connected to the distal tip  221  of the sheath  220 . When loading the medical instrument  100 K and the clip unit  400  from the distal end side B 1  of the applicator  200 K, by removing the hook main body  271  from the sheath  220 , the medical instrument  100 K and the clip unit  400  can be smoothly loaded into the applicator  200 K. 
     The slider  242  may be provided with a configuration for informing the user of rotation of the wire  232  and the medical device  100 K connected to the wire  232  around the longitudinal direction A. Specifically, the slider  242  and the operation unit main body  241  are provided with unevenness and colored markers, so that the user can visually recognize the rotation of the medical device  100 K around the longitudinal direction A and adjust the position of the medical device  100 K. 
     [Medical Instruments  100 K] 
       FIG.  43    is a perspective view of the medical device  100 K. 
     The medical device  100 K includes an indwelling member  1 K and a connecting member  2 . 
     The indwelling member  1 K has an arrowhead-shaped distal end A 1 , and is a member that is punctured into living tissue by suturing. The indwelling member  1 K includes a puncturing portion (distal portion)  11 , a rod-shaped portion (intermediate portion)  14 K, and a body portion (base end portion)  15 . The indwelling member  1 K is made of a biocompatible material, such as stainless steel. The indwelling member  1 K may be made of a bioabsorbable material such as polylactic acid. 
     The puncturing portion  11  is provided on the distal end side A 1  of the indwelling member  1 K and is formed in a substantially conical shape. The puncturing portion  11  has a distal end portion (first portion)  12  and a return portion (second portion)  13 . The distal end portion  12  is provided on the distal end side A 1  of the puncturing portion  11  and has a sharp distal end. The return portion  13  is provided on the proximal end side A 2  of the puncturing portion  11  and has the largest outer diameter in the puncturing portion  11 . 
     The rod-shaped portion  14 K is formed in a substantially cylindrical shape extending in the longitudinal direction A. The rod-shaped portion  14 K is connected to the puncturing portion  11  on the distal end side A 1 , and is connected to the body portion  15  on the proximal end side A 2 . The outer diameter of the return portion  13  is larger than the outer diameter of the rod-shaped portion  14 K. That is, at the connecting portion between puncturing portion  11  and rod-shaped portion  14 K, the outer diameter of puncturing portion  11  is larger than the outer diameter of rod-shaped portion  14 K. 
     The rod-shaped portion  14 K is curved in the longitudinal direction A. Specifically, the intermediate portion curves in the radial direction of the sheath  220  in the direction in which the puncturing portion  11  approaches the hook  270 . That is, as shown in  FIG.  45 A , in a state in which the indwelling member  1 K is arranged outside the sheath  220 , the distance (second distance D 2 ) between the puncturing portion  11  and the hook  270  in the radial direction of the sheath  220  is smaller than the distance (first distance D 1 ) between the body portion  15  and the hook  270 . 
     As shown in  FIGS.  44  and  45 A , the distance (third distance D 3 ) between the puncturing portion  11  and the hook  270  in a state (first state) in which the indwelling member  1 K protrudes from the sheath  220  by a first length L 1  is greater than the distance (fourth distance D 4 ) between puncturing portion  11  and hook  270  in a state (second state) in which the indwelling member  1 K protrudes from sheath  220  by a second length L 2  longer than first length L 1 . 
     The body portion  15  is formed in a substantially columnar shape extending in the longitudinal direction A. The body portion  15  has an enlarged diameter portion  16 , an engaging portion  17 , and a connecting portion  18  connected to the connecting member  2 . Note that the body portion  15  may be curved in the direction as the rod portion  14 K. 
     The enlarged diameter portion  16  is provided on the distal end side A 1  of the body portion  15  and connected to the rod-shaped portion  14 K. The enlarged diameter portion  16  is formed in a planar shape in which the distal end side A 1  is substantially perpendicular to the longitudinal direction A. The outer diameter of the enlarged diameter portion  16  is larger than the outer diameter of the rod-shaped portion  14 K. That is, at the connecting portion between the body portion  15  and the rod-shaped portion  14 K, the outer diameter of the body portion  15  is larger than the outer diameter of the rod-shaped portion  14 K. 
     For example, the length of the puncturing portion  11  in the longitudinal direction A is approximately 5 mm. In addition, the length of the rod-shaped portion  14 K in the longitudinal direction A (the length from the return portion  13  of the puncturing portion  11  to the enlarged diameter portion  16  of the body portion  15 ) is smaller than the spread width of a general clip, for example, about 10 mm to 20 mm long. 
     [Operation of Medical Instrument  100 K and Applicator  200 K] 
       FIGS.  44  to  46    are diagrams explaining the operation of the medical instrument  100 K and the applicator  200 K.  FIG.  45 A  is a side view of hook  270 .  FIG.  45 B  is a front view of hook  270  viewed from direction B in  FIG.  45 A .  FIG.  45 C  is a cross-sectional view of hook  270  along line C-C in  FIG.  45 A .  FIG.  45 D  is a cross-sectional view of hook  270  along line D-D in  FIG.  45 A . 
     As shown in  FIG.  44   , the connecting member  2  of the medical instrument  100 K loaded in the applicator  200 K is connected to the arrowhead hook portion  231  that passes through the sheath  220 . The engaging portion  17  is pressed by the inner peripheral surface of the sheath  220  and is in a retracted state. The rod-shaped portion  14 K of the medical device  100 K is elastically deformed so as to follow the shape of the sheath  220 . 
     As the slider  242  advances along the operation portion main body  241 , the arrowhead hook portion  231  advances. As shown in  FIG.  45 A , the medical device  100 K is advanced at least until the engagement portion  17  is out of the sheath  220 . 
     By coming out of the sheath  220 , the engaging portion  17  transitions from the retracted state to the protruding state, which is a basic posture. Since the engaging portion  17  in the projecting state engages with the distal tip  221  of the sheath  220 , it is not pulled into the sheath  220 . Therefore, the indwelling member  1 K is not pulled into the sheath  220  after coming out of the sheath  220 . 
     As shown in  FIG.  45 A , the rod-shaped portion  14 K of the indwelling member  1 K is released from elastic deformation as it protrudes from the sheath  220 , and assumes a curved shape with respect to the longitudinal direction B. At this time, the puncturing portion  11  of the indwelling member  1 K curves in a direction approaching the hook main body  271  of the hook  270 . The puncturing portion  11  of the indwelling member  1 K moves to the distal end side B 1  of the hook distal end portion  272  of the hook  270 . More specifically, the return portion  13  of the puncturing portion  11  moves to the distal end side B 1  of the hook distal end portion  272 . At this time, the puncturing portion  11  is inserted through the path  273  formed by the hook distal end portion  272 . 
     As shown in  FIG.  46   , the slider  242  retreats along the operation portion main body  241 , whereby the arrowhead hook portion  231  retreats. The connecting member  2  connected to the arrowhead hook portion  231  pulls the indwelling member  1 K. Since the engaging portion  17  in the projecting state engages with the distal tip  221  of the sheath  220 , it is not pulled into the sheath  220 . The distal end connecting portion  21  of the connecting member  2  is separated from the connecting portion  18  of the indwelling member  1 K by, for example, a part of the distal end connecting portion  21  being broken. The connecting member  2  may be separated from the connecting portion  18  of the indwelling member  1 K by, for example, elastic deformation or plastic deformation of part of the distal end connecting portion  21 . 
     As shown in  FIG.  46   , in a state in which the connection between the wire  232  and the retention member  1 K is released, the retention member  1 K is released when the endoscope  300  and the sheath  220  are separated from the retention member  1 K. 
     As described above, the seventh embodiment of the present disclosure has been described in detail with reference to the drawings, but the specific configuration is not limited to this embodiment, and design changes and the like are included within the scope of the present disclosure. Also, the constituent elements shown in the above-described embodiment and modifications shown below can be combined as appropriate.