Stent Delivery System

Abstract

By advancing the chuck nut (52) relative to the collet jaws (51b) provided at the proximal end (30p) of the pusher catheter (30) and arranged along the outer periphery of the guiding catheter (10), the amount by which the collet jaws (51b) approach the guiding catheter (10) changes.

Description

Technical Field

[0001] The invention relates to a stent delivery system. Background Art

[0002] Conventionally, a stent delivery system is used, which delivers a stent through an endoscope channel to a desired location such as a stricture in the bile duct and leaves the stent at the location.

[0003] The stent delivery system has a chuck mechanism for clamping the guide catheter at the operating part. The chuck mechanism determines the size of the guide catheter released from the front end of the stent by clamping the guide catheter. Since the length of the stent varies according to the operation, the size of the guide catheter released from the front end of the stent is adjusted in accordance with the length of the stent.

[0004] In addition, various mechanisms for clamping tubular or linear structures such as guide catheters or guide wires have been proposed. The medical guide wire described in Patent Document 1 is clamped and fixed by a chuck portion, and the chuck portion is housed inside the front outer tube and the rear outer tube that are threaded together. By screwing the rear outer tube into the front outer tube, the inner wall surface of the front end of the rear outer tube moves against the tapered outer surface of the chuck member. By pressing the rear outer tube at this time, the slit forming portion is pushed toward the hollow portion of the shaft core and contracts, tightening the wire body from the surrounding area, thereby clamping and fixing the wire body.

[0005] Prior art documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent No. 2923298 Summary of the invention

[0008] Problem that the invention aims to solve

[0009] However, the medical guide wire described in Patent Document 1 is structured such that the more the front outer tube is screwed into the rear outer tube, the more the slit forming portion is pushed toward the hollow portion of the shaft core and contracts. If the front outer tube is screwed into the rear outer tube excessively, the force of the slit forming portion tightening the wire body becomes too large, and if it is not screwed in enough, the force becomes insufficient. Therefore, it is difficult for the medical guide wire described in Patent Document 1 to stably clamp the wire body with an appropriate tightening force.

[0010] In view of the above circumstances, an object of the present invention is to provide a stent delivery system that can easily and stably clamp a guide catheter with an appropriate clamping force.

[0011] Solutions for solving problems

[0012] The stent delivery system of the first technical solution of the present invention includes: a guiding catheter that can penetrate through the channel of the endoscope and through which a guide wire can penetrate; a stent formed in a tubular shape through which the guiding catheter can penetrate; a push catheter formed in a tubular shape through which the guide wire can penetrate and through which the guiding catheter can penetrate, and the push catheter is disposed at a position closer to the proximal end than the stent; and a collet chuck provided at the proximal end of the push catheter through which the guiding catheter extending from the proximal end of the push catheter penetrates, and the collet chuck can clamp the guiding catheter. The collet chuck has: collets disposed along the outer circumference of the guiding catheter; and a chuck nut that can move forward and backward relative to the collets and through which the guiding catheter penetrates. The inner circumferential surface of the chuck nut facing the central axis of the collet chuck has: a first region where, as the inner circumferential surface approaches the collets while contacting the collets, the inner circumferential surface tightens the collets to bring the collets closer to the central axis of the guiding catheter; and a second region where, as the inner circumferential surface approaches the collets while contacting the collets, the amount by which the inner circumferential surface brings the collets closer to the central axis of the guiding catheter is smaller than the corresponding amount in the first region where the inner circumferential surface brings the collets closer to the central axis of the guiding catheter.

[0013] Effect of the Invention

[0014] According to the above stent delivery system, a stent delivery system that can easily clamp the guiding catheter with an appropriate tightening force can be provided. Description of the Drawings

[0015] Figure 1 is a side view of the stent delivery system according to an embodiment of the present invention.

[0016] Figure 2 is an enlarged cross-sectional view of the operation part of the stent delivery system according to an embodiment of the present invention, showing the state where the guiding catheter is released.

[0017] Figure 3 is an enlarged view of the operation part of the stent delivery system according to an embodiment of the present invention, showing the state where the guiding catheter is released.

[0018] Figure 4 is an enlarged view of the operation part of the stent delivery system according to an embodiment of the present invention, showing the state where the guiding catheter is fixed.

[0019] Figure 5 is an enlarged cross-sectional view of the collet chuck of the stent delivery system according to an embodiment of the present invention, showing the first region.

[0020] Figure 6It is an enlarged cross-sectional view of the collet chuck of the stent delivery system according to an embodiment of the present invention, and it is a view of the second region.

[0021] Figure 7 It is a cross-sectional view showing a modified example of the collet chuck according to an embodiment of the present invention.

[0022] Figure 8 It is a cross-sectional view showing another modified example of the collet chuck according to an embodiment of the present invention. Detailed Embodiment

[0023] Refer to Figures 1 to 8 The first embodiment of the present invention will be described. Hereinafter, in the stent delivery system, the side inserted into the stenosis will be described as the front end side, and the user side will be described as the proximal end side.

[0024] The stent delivery system 100 of the present embodiment is a system that causes the stent 20 to reach a desired position such as a stenosis in the bile duct through an endoscopic channel and leaves the stent 20 at that position.

[0025] Figure 1 It is a side view of the stent delivery system 100 of the present embodiment. As Figure 1 shown, the stent delivery system 100 includes a guide wire G, a guiding catheter 10, a stent 20, a push catheter 30, and an operation unit 40.

[0026] The guide wire G is used to guide the guiding catheter 10, the stent 20, and the push catheter 30 to the stenosis. The guide wire G is introduced into the bile duct through the channel of the endoscope. The front end of the guide wire G is inserted to a position beyond the stenosis.

[0027] The guiding catheter 10 is used to assist the entry of the stent 20 into the stenosis. The guiding catheter 10 has a catheter lumen tube 11 and an operation wire 12. The catheter lumen tube 11 is a tubular member formed of resin or the like. The guide wire G passes through the catheter lumen tube 11. The guiding catheter 10 is guided to the stenosis by the guide wire G.

[0028] The stent 20 is disposed on the outer periphery of the catheter lumen tube 11. In the state where the stent 20 is disposed, the front end 11t of the catheter lumen tube 11 is exposed from the stent 20. The front end 11t of the catheter lumen tube 11 of the guiding catheter 10 is inserted into the stenosis prior to the stent 20. The catheter lumen tube 11 widens the stenosis, thereby assisting the entry of the stent 20 into the stenosis.

[0029] The operation wire 12 is used to push and pull the catheter lumen tube 11 to move it to the front end side and the proximal end side. The operation wire 12 is connected to the proximal end 11p of the catheter lumen tube 11.

[0030] The stent 20 is a tubular member formed of resin or the like. The stent 20 is disposed on the outer periphery of the catheter lumen tube 11 of the guiding catheter 10. The stent 20 is joined and fixed to the catheter lumen tube 11.

[0031] The pusher catheter 30 is used to place the stent 20 at the stenosis. The pusher catheter 30 is a tubular member formed of resin or the like. A guide wire G and the guiding catheter 10 penetrate through the pusher catheter 30. The pusher catheter 30 is disposed at a position closer to the proximal end side of the guiding catheter 10 than the stent 20.

[0032] The inner diameter of the pusher catheter 30 is larger than the outer diameter of the catheter lumen tube 11 of the guiding catheter 10. The inner diameter and outer diameter of the pusher catheter 30 are substantially equal to the inner diameter and outer diameter of the stent 20. By pulling the guiding catheter 10 toward the proximal end side, the stent 20 fixed to the guiding catheter 10 is pulled toward the proximal end side. The stent 20 being pulled toward the proximal end side abuts against the pusher catheter 30. When the guiding catheter 10 is pulled toward the proximal end side with a force equal to or greater than a certain magnitude in a state where the stent 20 abuts against the pusher catheter 30, a force is generated between the stent 20 and the guiding catheter 10 that causes them to separate from each other. By generating a force between the stent 20 and the guiding catheter 10 that causes them to separate from each other, the stent 20 separates from the guiding catheter 10, and the fixation between the guiding catheter 10 and the stent 20 is released.

[0033] When the guiding catheter 10 is pulled toward the proximal end side in a state where the fixation between the guiding catheter 10 and the stent 20 has been released, the guiding catheter 10 moves toward the proximal end side. Since the stent 20 is pressed by the pusher catheter 30, it does not move toward the proximal end side. The stent 20 detaches from the guiding catheter 10 and remains in place.

[0034] A guide wire port 30a is formed at a position between the distal end 30t and the proximal end 30p on the outer peripheral surface of the pusher catheter 30. The guide wire G is released from the guide wire port 30a.

[0035] The operation unit 40 clamps the guiding catheter 10 extending from the proximal end 30p of the pusher catheter 30. The operation unit 40 clamps the guiding catheter 10 and adjusts the length L of the guiding catheter 10 released from the distal end 30t of the pusher catheter 30.

[0036] Figure 2 It is an enlarged view of the operation unit 40. The operation unit 40 pushes and pulls the pusher catheter 30 along the guide wire G. The operation unit 40 adjusts the position of the guiding catheter 10 relative to the pusher catheter 30. As Figure 2 shown, the operation unit 40 includes a housing 40a, a rod 41, and a collet chuck 50. The collet chuck 50 includes a collet portion 51 and a chuck nut 52.

[0037] As Figure 2As shown, the housing 40a is provided at the proximal end 30p of the pusher catheter 30. The housing 40a is formed in a substantially cylindrical shape. The hollow portion of the housing 40a communicates with the hollow portion of the pusher catheter 30. The housing 40a has a front-end side hollow portion 40b, an internal space 40c, a notch portion 40d, and a proximal-end side hollow portion 40e. The front-end side hollow portion 40b, the internal space 40c, and the proximal-end side hollow portion 40e communicate with each other.

[0038] The front-end side hollow portion 40b is formed along the central axis O of the housing 40a. The front-end side hollow portion 40b communicates with the hollow portion of the pusher catheter 30. The operating wire 12 extending from the proximal end 30p of the pusher catheter 30 through the guiding catheter 10 penetrates the front-end side hollow portion 40b.

[0039] The internal space 40c is formed along the central axis O of the housing 40a. The internal space 40c is formed at a position closer to the proximal end side than the front-end side hollow portion 40b and communicates with the front-end side hollow portion 40b. The internal space 40c is formed to near the outer peripheral surface 40f of the housing 40a as compared with the front-end side hollow portion 40b. The operating wire 12 penetrates the internal space 40c.

[0040] The notch portion 40d is formed on the outer peripheral surface 40f on the proximal end side of the internal space 40c and communicates the internal space 40c with the space outside the housing 40a. The notch portion 40d is formed over a range of approximately 90 degrees around the central axis O of the housing 40a.

[0041] The proximal-end side hollow portion 40e is formed along the central axis O of the housing 40a. The proximal-end side hollow portion 40e is formed at a position closer to the proximal end side than the internal space 40c of the housing 40a and communicates with the internal space 40c. The proximal-end side hollow portion 40e communicates with the space outside the housing 40a. The operating wire 12 penetrates the proximal-end side hollow portion 40e.

[0042] The rod 41 is used to switch between the fixed state and the released state of the guiding catheter 10 achieved by the operating portion 40. The rod 41 is integrally formed with the chuck nut 52 of the collet chuck 50, and rotates the collet chuck 50 to clamp and release the operating wire 12, thereby switching between the fixed state and the released state.

[0043] The rod 41 is disposed in the internal space 40c of the housing 40a. The rod 41 projects from the notch portion 40d formed on the outer peripheral surface 40f of the housing 40a. The rod 41 is mounted on the housing 40a so as to be rotatable about the central axis O of the housing 40a. The rod 41 can rotate about the central axis O along the notch portion 40d by approximately 90 degrees.

[0044] Figure 3 It is a view of the state where the operating portion 40 has released the guiding catheter 10 (released state). Figure 3 It is the same as the state shown in Figure 2 the state shown.Figure 4 This is a view of the state where the operating section 40 fixes the guiding catheter 10 (fixed state). As Figure 3 and Figure 4 shown, the release state and the fixed state of the guiding catheter 10 are switched by rotating the lever 41 about the central axis O of the housing 40a. When the lever 41 is rotated approximately 90 degrees to the right as viewed from the proximal end side toward the distal end side in the release state, it becomes the fixed state. When the lever 41 is rotated approximately 90 degrees to the left as viewed from the proximal end side toward the distal end side in the fixed state, it becomes the release state.

[0045] In the collet chuck 50, the collet portion 51 is fixed to the housing 40a, and the operating wire 12 is clamped by the collet portion 51 and fixed relative to the housing 40a. The chuck nut 52 of the collet chuck 50 is operated by the lever 41. As Figure 2 shown, the collet chuck 50 is disposed in the internal space 40c of the housing 40a. The collet chuck 50 is disposed at a position closer to the distal end side than the lever 41. The collet portion 51 and the chuck nut 52 of the collet chuck 50 are formed to be able to move relative to each other in the forward and backward directions. The collet portion 51 has an external thread portion (thread) 51a and collets 51b.

[0046] The external thread portion 51a is formed in a substantially cylindrical shape. The external thread portion 51a is disposed such that its central axis CO overlaps with the central axis O of the housing 40a. The external thread portion 51a is fixed in such a manner that its relative position with respect to the housing 40a remains unchanged. The external thread portion 51a has a hollow portion 51c and an external thread 51d. The hollow portion 51c is formed along the central axis CO. The external thread portion 51a is disposed such that the hollow portion 51c communicates with the front-end side hollow portion 40b of the housing 40a. The operating wire 12 of the guiding catheter 10 passes through the hollow portion 51c. The external thread 51d is formed along the central axis CO on the outer peripheral surface of the external thread portion 51a.

[0047] The collets 51b are formed as protrusions protruding from the end portion 51e on the proximal end side of the external thread portion 51a toward the proximal end side. In the present embodiment, four collets 51b are provided. The four collets 51b are symmetrically disposed with respect to the central axis CO along the outer periphery of the operating wire 12 of the guiding catheter 10.

[0048] The collets 51b have an inner side surface 51f and an outer side surface 51g. The inner side surface 51f faces the operating wire 12 of the guiding catheter 10. The inner side surface 51f is along the central axis CO.

[0049] The outer side surface 51g is formed on the side opposite to the inner side surface 51f in the collets 51b. The outer side surface 51g has an outer peripheral tapered surface 51h and a chuck guiding surface 51i. The outer peripheral tapered surface 51h is formed on the front-end side and is farther away from the central axis CO as it approaches the proximal end side. The chuck guiding surface 51i is formed at a position closer to the proximal end side than the outer peripheral tapered surface 51h and is inclined closer to the central axis CO side as it approaches the proximal end side.

[0050] The chuck nut 52 is formed in a substantially tubular shape. The chuck nut 52 is arranged such that its central axis NO overlaps with the central axis O of the housing 40a. The chuck nut 52 is supported so as to be rotatable about the central axis O. The operating wire 12 of the guide catheter 10 passes through the hollow portion of the chuck nut 52. The chuck nut 52 is integrally formed with the rod 41. The rod 41 projects from the base end side of the outer peripheral surface of the chuck nut 52.

[0051] The chuck nut 52 has an internal thread portion (thread) 52a, a tapered portion 52b, and a straight tube portion 52c. The internal thread portion 52a is formed on the front end side of the chuck nut 52. The internal thread portion 52a has an internal thread 52e formed on its inner peripheral surface. The internal thread 52e is threadedly engaged with the external thread 51d of the collet portion 51.

[0052] The tapered portion 52b is formed at a position closer to the base end side than the internal thread portion 52a. The tapered portion 52b has an inner peripheral tapered surface (inner peripheral surface) 52t on the inner peripheral surface of the base end side. The inner peripheral tapered surface 52t is reduced in diameter so as to be closer to the central axis NO side as it approaches the base end side. As Figure 5 shown, the first region R1 is provided on the inner peripheral surface of the chuck nut 52. The first region R1 is a region provided on the inner peripheral surface of the chuck nut 52 and is reduced in diameter so as to be closer to the central axis NO side as it approaches the base end side.

[0053] As Figure 2 shown, the straight tube portion 52c is formed at a position closer to the base end side than the tapered portion 52b. The straight tube portion 52c is formed in a cylindrical shape. The diameter of the straight tube inner peripheral surface (inner peripheral surface) 52d of the straight tube portion 52c is substantially constant. The straight tube inner peripheral surface 52d is continuous with the inner peripheral tapered surface 52t.

[0054] As Figure 5 and Figure 6 shown, a boundary position P2 and a second region R3 are provided in the straight tube portion 52c. The boundary position P2 is a position provided on the inner peripheral surface of the chuck nut 52 and is the boundary position between the first region R1 and the second region R3. The boundary position P2 is provided at the front end side end portion 52f of the straight tube inner peripheral surface 52d of the straight tube portion 52c.

[0055] The second region R3 is a region provided on the inner peripheral surface of the chuck nut 52 and is a region where the degree of diameter reduction closer to the central axis NO side as it approaches the base end side is gentler than that of the first region R1 and does not reduce in diameter in this embodiment. The second region R3 includes the boundary position P2. The second region R3 is provided on the straight tube inner peripheral surface 52d of the straight tube portion 52c.

[0056] Next, the operation of adjusting the length L of the guide catheter 10 released from the front end 30t of the push catheter 30 as shown in Figure 1 will be described.

[0057] First, the user sets the length L to an appropriate length by pushing and pulling the operating wire 12 in the release state shown in Figure 2 and Figure 3 . In the release state, as shown in Figure 2 , the collet portion 51 and the chuck nut 52 are not in contact (non-contact state).

[0058] The user rotates the rod 41 of the operating portion 40 from the release state toward the fixed state shown in Figure 4 about the central axis O of the housing 40a. Figure 5 FIG. is a view showing the collet chuck 50 when the rod 41 is rotated about the central axis O from the release state.

[0059] As shown in Figure 5 , when the rod 41 is rotated about the central axis O, the internal thread 52e of the chuck nut 52 rotates relative to the external thread 51d of the collet portion 51, and the chuck nut 52 approaches the collet portion 51.

[0060] When the chuck nut 52 approaches the collet portion 51, the collet 51b of the collet portion 51 abuts against the inner peripheral surface of the chuck nut 52. First, the chuck guide surface 51i of the collet 51b abuts against the inner peripheral tapered surface 52t of the chuck nut 52. The collet 51b abuts within the first region R1 of the chuck nut 52 (first abutment state).

[0061] When the rod 41 approaches the fixed state, the tip 51p of the collet 51b of the collet chuck 50 deflects toward the central axis O of the housing 40a when the chuck nut 52 approaches the collet portion 51. When the chuck nut 52 approaches the collet portion 51 in the first abutment state, the tip 51p of the inner side surface 51f of the collet 51b deflects and approaches the central axis O of the housing 40a. When the chuck nut 52 approaches the collet portion 51 in the first abutment state, the chuck guide surface 51i slides relative to the inner peripheral tapered surface 52t, and the tip 51p of the collet 51b deflects toward the central axis O of the housing 40a.

[0062] When the chuck nut 52 approaches the collet portion 51, the tip 51p side of the inner side surface 51f of the collet 51b immediately abuts against the operating wire 12 of the guide conduit 10, thereby clamping the operating wire 12.

[0063] When the chuck nut 52 further approaches the collet portion 51, the outer side surface 51g of the collet 51b abuts against the end portion 52f on the front end side of the inner peripheral surface 52d of the straight pipe portion 52c of the chuck nut 52. The collet 51b abuts at the boundary position P2 of the chuck nut 52.

[0064] When the collet 51b abuts against the boundary position P2, the inner peripheral surface 52d of the straight tube portion that is at a predetermined distance from the central axis 10o of the guiding catheter 10 clamps the collet 51b, and the distance between the end 51p of the inner side surface 51f of the collet 51b and the central axis 10o becomes a predetermined distance. At the boundary position P2, the outer peripheral tapered surface 51h of the collet 51b is substantially parallel to the central axis O of the housing 40a. At the boundary position P2, the outer peripheral tapered surface 51h of the collet 51b is disposed on the side closer to the central axis O than the inner peripheral surface 52d of the straight tube portion. At the boundary position P2, the collet 51b clamps the operating wire 12 of the guiding catheter 10 with a predetermined force.

[0065] When the chuck nut 52 is further moved closer to the collet portion 51, the collet 51b abuts against the second region R3 of the chuck nut 52 (second abutting state).

[0066] In the stent delivery system 100 of the present embodiment, the diameter of the inner peripheral surface 52d of the straight tube portion is substantially constant and does not shrink. Therefore, when the chuck nut 52 is moved closer to the collet portion 51 in the second abutting state, the end 51p of the inner side surface 51f of the collet 51b does not deflect toward the central axis 10o of the guiding catheter 10, and the distance is maintained.

[0067] Figure 6 It is a diagram showing the operation of the collet chuck 50 in the second region. As Figure 6 shown, in the second region, the outer peripheral tapered surface 51h of the collet 51b is substantially parallel to the central axis O of the housing 40a. In the second region R3, the collet 51b clamps the operating wire 12 of the guiding catheter 10 with a predetermined force.

[0068] In the second region R3, when the chuck nut 52 is moved closer to the collet portion 51, the rod 41 is immediately disposed at a fixed position.

[0069] According to the stent delivery system 100 of the present embodiment, the chuck nut 52 is provided with a first region R1 and a second region R3. Even when the chuck nut 52 is moved closer to and abuts against the collet portion 51 in the second region R3, the end 51p of the inner side surface 51f of the collet 51b maintains the distance from the central axis 10o of the guiding catheter 10 and clamps the operating wire 12. In the second region R3, the collet 51b clamps the operating wire 12 with a predetermined force. Therefore, even if there is an offset in the relative position between the fixed collet 51b and the chuck nut 52 due to manufacturing deviations or the like, the stent delivery system 100 can easily clamp the guiding catheter 10 with an appropriate clamping force.

[0070] In the second region R3, the shape of the collet 51b is maintained such that the outer peripheral conical surface 51h of the collet 51b is along the central axis O of the housing 40a. The shape of the collet 51b is maintained by the outer peripheral conical surface 51h abutting against the inner peripheral surface 52d of the straight tube portion 52c of the straight tube portion. Thereby, the distance between the inner side surface 51f of the collet 51b and the central axis 10o of the guide catheter 10 is maintained at a predetermined distance. The end 51p of the inner side surface 51f of the collet 51b clamps the operating wire 12 of the guide catheter 10 with a force of a predetermined magnitude. Therefore, without forming a complex shape, the collet 51b clamps the guide catheter 10 with an appropriate tightening force in the second region R3.

[0071] The collet 51b has a chuck guide surface 51i. Thereby, in the first region R1, when the chuck nut 52 is brought close to the collet portion 51, the chuck guide surface 51i slides relative to the inner peripheral conical surface 52t of the chuck nut 52, and the end 51p of the collet 51b is easily deflected toward the central axis O side of the housing 40a. Therefore, the collet chuck 50 easily clamps the operating wire 12 of the guide catheter 10.

[0072] The collet chuck 50 forms a thread in the collet portion 51 and the chuck nut 52 and is threadedly engaged, so that the collet 51b and the chuck nut 52 can move relative to each other forward and backward. Therefore, when the collet 51b abuts against the chuck nut 52 and approaches the chuck nut 52, the user can easily bring the collet 51b closer with a light force.

[0073] Since the collet portion 51 is fixed so that the relative position is unchanged with respect to the housing 40a extending from the push catheter 30, the collet portion 51 is fixed so that the relative position is unchanged with respect to the push catheter 30. Therefore, when the collet 51b clamps the operating wire 12 and the collet 51b and the chuck nut 52 approach each other relative to each other in the second region R3, the collet 51b does not move the guide catheter 10 relative to the push catheter 30.

[0074] The housing 40a has a rod 41. Therefore, it is easy for the user to move the collet portion 51 and the chuck nut 52 relative to each other forward and backward.

[0075] As described above, the embodiments of the present invention have been described in detail with reference to the drawings, but the specific structure is not limited to this embodiment, and also includes design changes and the like in the field that do not deviate from the gist of the present invention. In addition, the constituent elements shown in the above embodiments and the following modified examples can be appropriately combined and configured.

[0076] For example, it can also be that the diameter of the inner peripheral surface of the straight pipe portion constituting the second region R3 is not constant. It can also be that the diameter of the inner peripheral surface of the straight pipe portion is reduced more gently than the degree of reduction of the inner peripheral tapered surface 52t of the chuck nut that constitutes the first region R1. If the degree of reduction of the diameter of the inner peripheral surface of the straight pipe portion is gentler than the degree of reduction of the inner peripheral tapered surface 52t, when the chuck nut 52 approaches the collet portion 51, in terms of the amount by which the end 51p of the inner side surface 51f deflects and approaches the central axis 10o side, the second contact state is smaller than the first contact state. Thus, when the chuck nut 52 approaches the collet portion 51 in the second contact state, an increase in the force with which the collet 51b tightens the guide catheter 10 is suppressed. Therefore, even if there is an offset in the relative position between the collet 51b in the fixed state and the chuck nut due to manufacturing deviations or the like, it is easy to clamp the guide catheter 10 with an appropriate tightening force.

[0077] It can also be as Figure 7 shown that the collet chuck does not have the inner peripheral tapered surface 52t. It can also be configured such that the chuck guide surface 51i abuts against the corner of the end 52f of the straight pipe portion 52c without abutting against the inner peripheral tapered surface 52t. It can also be that when the collet portion 51 and the chuck nut are relatively moved closer in a state where the corner of the end 52f of the pipe portion 52c abuts against the collet 51b, the end 51p of the collet 51b deflects toward the central axis O side of the housing 40a. The first region R1 can also have its definition expanded to a region where when the approaching collet 51b abuts and the collet portion 51 and the chuck nut are relatively moved closer, the end 51p deflects toward the central axis O side.

[0078] It can also be as Figure 8 shown that the collet chuck does not have the straight pipe portion 52c. It can also be that appropriate curvatures are formed on the inner side surface 61f and the outer side surface 61g of the collet portion 61 so that the collet 61b abuts against the inner peripheral tapered surface 52t of the chuck nut 62 while approaching the chuck nut 62. Thus, it can also be that when the collet portion 51 and the chuck nut are relatively moved closer in a state where the collet 51b abuts against the chuck nut 62 at a position closer to the proximal end side than the first region R1, the amount by which the end 51p deflects toward the central axis O side is smaller than that in the first region R1. Thus, it can also be that the collet chuck clamps the guide catheter 10 with an appropriate tightening force. The second region R3 can also have its definition expanded to a region where when the collet 51b abuts and the collet portion 51 and the chuck nut are relatively moved closer, the amount by which the end 51p deflects toward the central axis O side is smaller than that in the first region R1.

[0079] The number of collets is not limited to four. The collets can also be integrated. There can also be two or more.

[0080] The rod can also be configured to be in a fixed state when rotated counterclockwise when viewed from the proximal end side toward the distal end side, and in a released state when rotated clockwise. The rotatable range of the rod may not be 90 degrees.

[0081] The guiding catheter may not have the operating wire 12. In this case, only the catheter lumen tube constitutes the guiding catheter, and the operating portion 40 holds the catheter lumen tube. A guide wire opening is formed on the outer peripheral surface of the guiding catheter, and the guide wire G is released from the guide wire opening.

[0082] Description of Reference Numerals

[0083] 10. Guiding catheter; 10o. Central axis; 20. Stent; 30. Pusher catheter; 40. Operating portion; 40a. Housing; 41. Rod; 50. Sleeve jaw chuck; 51. Sleeve jaw portion; 51a. External thread portion (thread); 51b. Sleeve jaw; 51f. Inner surface; 51g. Outer surface; 51h. Outer peripheral tapered surface; 51i. Chuck guiding surface; 52. Chuck nut; 52a. Internal thread portion (thread); 52b. Tapered portion; 52c. Straight tube portion; 52d. Inner peripheral surface of the straight tube portion (inner peripheral surface); 52t. Inner peripheral tapered surface (inner peripheral surface); 61b. Sleeve jaw; 61f. Inner surface; 61g. Outer surface; 62. Chuck nut; 100. Stent delivery system; G. Guide wire; O. Central axis; P2. Boundary position; R1. First region; R3. Second region.

Claims

1. A stent delivery system, wherein, the stent delivery system includes: a guiding catheter that can penetrate through the channel of an endoscope and can allow a guide wire to penetrate through; a stent that is formed in a tubular shape and can allow the guiding catheter to penetrate through; a pushing catheter that is formed in a tubular shape and can allow a guide wire to penetrate through and can also allow the guiding catheter to penetrate through, and the pushing catheter is disposed at a position closer to the proximal end side than the stent; and a collet chuck that is provided at the proximal end of the pushing catheter and allows the guiding catheter extending from the proximal end of the pushing catheter to penetrate through, and the collet chuck can clamp the guiding catheter, the collet chuck has: collets that are arranged along the outer circumference of the guiding catheter; and a chuck nut that is configured to be able to move forward and backward relative to the collets and allows the guiding catheter to penetrate through, the inner circumferential surface of the chuck nut facing the central axis of the collet chuck has: a first region, in this first region, as the inner circumferential surface approaches the collets while contacting the collets, the inner circumferential surface tightens the collets to make the collets approach the central axis of the guiding catheter; and a second region, in this second region, as the inner circumferential surface approaches the collets while contacting the collets, the amount by which the inner circumferential surface makes the collets approach the central axis of the guiding catheter is smaller than the corresponding amount in the first region where the inner circumferential surface makes the collets approach the central axis of the guiding catheter.

2. The stent delivery system according to claim 1, wherein, the first region is reduced in diameter toward the proximal end side, the degree of diameter reduction of the second region toward the proximal end side is smaller than the degree of diameter reduction of the first region toward the proximal end side.

3. The stent delivery system according to claim 2, wherein, in a state where the collets are not in contact with the chuck nut, the inner side surface of the collets facing the guiding catheter extends along the central axis of the collet chuck, and the outer side surface of the collets on the side opposite to the inner side surface has an outer circumferential tapered surface that is farther away from the central axis of the collet chuck as it gets closer to the chuck nut, the chuck nut is formed in a substantially tubular shape, the inner circumferential surface has: an inner circumferential tapered surface that has the first region; and a straight tube portion inner circumferential surface that is continuously formed on the proximal end side with the inner circumferential tapered surface, and the straight tube portion inner circumferential surface is formed inside a cylindrical straight tube portion and has the second region, with respect to the collet chuck, as the collets and the chuck nut approach each other, the outer side surface of the collets contacts the first region of the inner circumferential tapered surface of the chuck nut, and the outer circumferential tapered surface of the collets contacts the second region of the straight tube portion inner circumferential surface of the chuck nut.

4. The stent delivery system according to claim 3, wherein, the outer side surface of the collets has a chuck guiding surface that is continuously formed on the chuck nut side with the outer circumferential tapered surface, and the chuck guiding surface is inclined so as to be closer to the central axis side of the collet chuck as it gets closer to the chuck nut, the chuck guiding surface of the collets contacts the first region of the inner circumferential tapered surface of the chuck nut.

5. The stent delivery system according to claim 1 or 4, wherein, a thread is formed between the collet chuck and the chuck nut, and the collet and the chuck nut rotate relative to each other, so that the collet and the chuck nut move forward and backward relative to each other.

6. The stent delivery system according to any one of claims 1 to 4, wherein, the collet is set to have a constant relative position with respect to the push catheter.

7. The stent delivery system according to any one of claims 1 to 4, wherein, the chuck nut has a rod protruding from the outer peripheral surface.

8. The stent delivery system according to claim 2, wherein, the second region of the inner peripheral surface of the chuck nut is parallel to the central axis of the guide catheter.

9. The stent delivery system according to any one of claims 1 to 4, wherein, the guide catheter has: a catheter lumen tube for setting the stent; and an operating wire connected to the catheter lumen tube, and the collet chuck clamps the operating wire.

10. The stent delivery system according to claim 5, wherein, the chuck nut has a rod protruding from the outer peripheral surface, and the rod is used to rotate the collet and the chuck nut relative to each other to clamp and release the guide catheter, thereby switching between the fixed state of the guide catheter and the state of releasing the guide catheter.

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