Medical stent and stent delivery device

Abstract

To provide a medical stent and a stent delivery device capable of easily grasping the position of a distal end under radioscopy.SOLUTION: A medical stent includes a main body having a tubular member and a reinforcing member wound in a spiral shape and embedded between an inner peripheral surface and an outer peripheral surface of the tubular member, a first locking member having a first fixed end fixed to a distal end side of the main body and a first free end located outside the tubular member and extending from the first fixed end to the first free end, a second fixed end fixed to a proximal end side of the main body, and a second free end located outside the tubular member. A second locking member extending from a second fixed end to a second free end, The main body has a first region, a second region, and a third region in which winding pitches of the reinforcing material are different from each other, the first region is a region located between the distal end of the main body and the first fixed end, the second region is a region in which the reinforcing material is wound at a winding pitch larger than that of the first region, and the third region is a region in which the reinforcing material is wound at a winding pitch larger than that of the second region.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a medical stent and a stent delivery device. [Background technology]

[0002] Conventionally, stents that are placed in the bile duct for the purpose of treating bile duct strictures have been known (for example, Patent Document 1). The stent placed in the bile duct is positioned along the bile duct and maintains space within the bile duct.

[0003] Conventional stents, such as the stent described in Patent Document 1, are configured by embedding a coiled wire in a resin body in order to improve rigidity and flexibility.

[0004] When placing a stent in the bile duct, the surgeon can determine the position of the stent by checking the metal wire under X-ray fluoroscopy, which allows the surgeon to place the stent at the desired position within the bile duct. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 6995219 Summary of the Invention [Problem to be solved by the invention]

[0006] However, if a wire is not provided at the tip of a stent placed in a bile duct, the surgeon may not be able to accurately determine the position of the tip of the stent under X-ray fluoroscopy.

[0007] In view of the above circumstances, an object of the present invention is to provide a medical stent and a stent delivery device that allow the position of the tip to be easily grasped under X-ray fluoroscopy. [Means for solving the problem]

[0008] In order to solve the above problems, the present invention proposes the following means. The medical stent of the present invention includes a main body having a tubular member extending in a longitudinal direction, and a reinforcing material that is spirally wound around a longitudinal axis extending in the longitudinal direction and extends in the longitudinal direction, and is embedded between the inner peripheral surface of the tubular member and the outer peripheral surface of the tubular member, a first fixed end fixed to a distal end side of the main body in the longitudinal direction, and a first free end located radially outward of the main body relative to the outer peripheral surface of the tubular member, and includes a first locking member extending from the first fixed end to the first free end toward a base end in the longitudinal direction, a second fixed end fixed to the proximal end side of the main body, and a second free end located radially outward of the outer peripheral surface of the tubular member. and a second free end for positioning the reinforcing material at the distal end, and a second locking member extending from the second fixed end to the second free end toward the distal end, wherein the main body has a first region, a second region, and a third region in which the winding pitch of the reinforcing material is different from one another, the first region is a region located between the distal end of the main body and the first fixed end in the longitudinal direction, the second region is located on the proximal end side of the first region, and is a region in which the reinforcing material is wound helically at a winding pitch larger than that of the first region, and the third region is located on the proximal end side of the second region, and is a region in which the reinforcing material is wound helically at a winding pitch larger than that of the second region.

[0009] The stent delivery device of the present invention comprises a guide catheter having a guide tube through which a guide wire can be inserted and a wire connected to the guide tube, a pusher catheter having a first tube having a first lumen through which the wire can be inserted and a second tube connected to the distal end of the first lumen and having a second lumen through which the guide tube can be inserted, a connecting member having a loop through which the guide tube can be inserted and connected to the distal end of the pusher catheter, and a connecting member extending in the longitudinal direction and connected to the distal end of the second tube. and a stent located on the distal end side in the longitudinal direction relative to the distal end of the stent body, the stent comprising: a main body having a tubular member extending in the longitudinal direction and through which the guide tube is inserted; a reinforcing material that extends in the longitudinal direction by being spirally wound around a longitudinal axis extending in the longitudinal direction and embedded between the inner peripheral surface of the tubular member and the outer peripheral surface of the tubular member; a through-hole that penetrates the tubular member from the inner peripheral surface to the outer peripheral surface and is provided on the proximal end side in the longitudinal direction; a first fixed end fixed to the distal end side of the main body; a first locking member extending from the first fixed end to the first free end toward the base end, a second fixed end fixed to the base end side of the main body, and a second free end located outside the outer circumferential surface of the tubular member, and extending from the second fixed end to the second free end toward the tip end, the main body having a first region, a second region, and a third region in which the winding pitch of the reinforcing material is different from one another, and the first region is located at the tip end of the main body in the longitudinal direction. the second region is located on the base end side of the first region and is a region in which the reinforcing material is wound helically at a winding pitch greater than that of the first region; the third region is located on the base end side of the second region and is a region in which the reinforcing material is wound helically at a winding pitch greater than that of the second region; the loop of the connecting member is inserted into the through hole, and the guide tube is inserted into the loop, thereby positioning the stent relative to the pusher catheter. [Effects of the Invention]

[0010] According to the medical stent and stent delivery device of the present invention, it is possible to provide a medical stent and a stent delivery device that allow the position of the tip to be easily grasped under X-ray fluoroscopy. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is an overall view of a stent delivery device according to an embodiment of the present invention. [Figure 2] FIG. 1 is a side view of a stent according to an embodiment of the present invention. [Figure 3] FIG. [Figure 4] FIG. 2 is a schematic cross-sectional view of the stent delivery device. [Figure 5] 10A to 10C are diagrams showing the process of placing a stent using the stent delivery device. [Figure 6] FIG. 1 shows a deployed stent. [Figure 7] 10A and 10B show the process of pulling the stent into the channel of the endoscope. DETAILED DESCRIPTION OF THE INVENTION

[0012] A stent delivery device 1 and a medical stent 10 according to an embodiment of the present invention will be described with reference to the drawings.

[0013] FIG. 1 is an overall view of a stent delivery device 1 according to this embodiment. FIG. 2 is a side view of stent 10.

[0014] The stent delivery device 1 includes a medical stent (stent) 10 and a delivery catheter 100.

[0015] The stent 10 is a stent to be placed in the bile duct, and includes a tubular main body 11 and flaps 50 attached to both ends of the main body 11.

[0016] The main body 11 is a tubular member that has a distal end 12 and a proximal end 13 and extends along a longitudinal axis X1. The distal end 12 is the end that is positioned on the liver side when placed in the bile duct. The proximal end 13 is the end that is positioned on the duodenal papilla side when placed in the bile duct.

[0017] In the following description, the direction in which the longitudinal axis X1 extends will be referred to as the "longitudinal direction A." In addition, in the stent 10, the side where the tip 12 of the main body 11 is provided will be referred to as the "tip side (distal side) A1" in the longitudinal direction A, and the side where the base end 13 is provided will be referred to as the "base side (proximal side) A2" in the longitudinal direction A.

[0018] In addition, in the stent 10, the direction perpendicular to the longitudinal direction A is referred to as the "radial direction R", the side closer to the longitudinal axis X1 is referred to as the "inner side R1" in the radial direction R, and the side away from the longitudinal axis X1 is referred to as the "outer side R2" in the radial direction R.

[0019] FIG. 3 is a perspective view of stent 10 with the outer layer of stent 10 visible.

[0020] The main body 11 has an inner layer 20 made of resin, a metal wire (reinforcement material) 30 wound around the inner layer 20, and an outer layer 40 made of resin that covers the inner layer 20 and the wire 30.

[0021] The inner layer 20 and the outer layer 40 form a tubular "tubular member" extending in the longitudinal direction A in the main body 11.

[0022] The wire 30 is embedded in the main body 11 between the inner and outer circumferential surfaces of the tubular member.

[0023] The main body 11 has, for example, the same outer diameter from the distal end 12 to the proximal end 13 .

[0024] The inner layer 20 is a tube made of a resin material, such as PTFE (polytetrafluoroethylene) or PFA (perfluoroalkoxylalkane), that has a smooth surface and is biocompatible.

[0025] The wire 30 is a coil-shaped member spirally wound around the longitudinal axis X1 on the outer peripheral surface of the inner layer 20. By spirally winding the wire 30 between the inner and outer peripheral surfaces of the main body 11, buckling of the stent 10 can be suppressed and the flexibility of the stent 10 can be improved.

[0026] The wire 30 is made of a material that is radiopaque, such as tungsten steel or stainless steel.

[0027] The main body 11 has a plurality of regions with different winding pitches for the wire 30. The plurality of regions of the main body 11 will be described in detail later.

[0028] The outer layer 40 is formed of a resin material having elasticity, flexibility, and biocompatibility, such as urethane, polyethylene, etc. The outer layer 40 is also provided in the gaps between the wires 30 adjacent to each other in the longitudinal direction A.

[0029] The flap 50 has a first flap 51 provided on the distal end side A1 and a second flap 71 provided on the proximal end side A2.

[0030] The first flap 51 has a plurality of first fastening members 55. The first fastening members 55 are elongated members having a first fixed end 56 and a first free end 57, and extending between the first fixed end 56 and the first free end 57.

[0031] In the first locking member 55, a rib (joint) 58 extends from the first fixed end 56 to the tip side A1. In this embodiment, the width of the rib 58 is the same as the width of the first locking member 55.

[0032] The first locking member 55 is attached to the main body 11 by joining the rib 58 to the outer circumferential surface of the main body 11. The rib 58 is joined to the main body 11 by a joining method such as heat fusion or adhesive.

[0033] By joining the rib 58 to the main body 11, the first fixed end 56 of the first locking member 55 is fixed to the main body 11. In the first flap 51 connected to the main body 11, the first fixed end 56 is the boundary between the part joined to the main body 11 by thermal welding, adhesive, etc. and the part not joined to the main body 11.

[0034] The first free end 57 is located on the outer side R2 of the outer peripheral surface of the main body 11. The first locking member 55 extends from the first fixed end 56 toward the first free end 57 toward the base end side A2 and the outer side R2. The first locking member 55 gradually extends toward the outer side R2 toward the base end side A2.

[0035] The second flap 71 has a plurality of second fastening members 75. The second fastening members 75 are elongated members having a second fixed end 76 and a second free end 77, and extending between the second fixed end 76 and the second free end 77.

[0036] In the second locking member 75, a rib (joint) 78 extends from the second fixed end 76 to the base end side A2. In this embodiment, the width of the rib 78 is smaller than the width of the second locking member 75.

[0037] The second locking member 75 is attached to the main body 11 by joining the rib 78 to the outer circumferential surface of the main body 11. The rib 78 is joined to the main body 11 by a joining method such as heat fusion or adhesive.

[0038] By joining the rib 78 to the main body 11, the second fixed end 76 of the second locking member 75 is fixed to the main body 11. In the second flap 71 connected to the main body 11, the second fixed end 76 is the boundary between the part joined to the main body 11 by thermal welding, adhesive, etc. and the part not joined to the main body 11.

[0039] The second free end 77 is located on the outer side R2 of the outer peripheral surface of the main body 11. The second locking member 75 extends from the second fixed end 76 toward the second free end 77 toward the tip side A1 and the outer side R2. The second locking member 75 gradually extends toward the outer side R2 toward the tip side A1.

[0040] In this embodiment, the length of the second locking member 75 in the longitudinal direction A is shorter than the length of the first locking member 55 in the longitudinal direction A.

[0041] The number of first locking members 55 in the first flap 51 and the number of second locking members 75 in the second flap 71 can be set as appropriate. In this embodiment, the first flap 51 has three first locking members 55, and the second flap 71 has three second locking members 75. The three first locking members 55 and the three second locking members 75 are attached to the outer circumferential surface of the main body 11 at equal intervals around the longitudinal axis X1.

[0042] The phases on the outer circumferential surface of the main body 11 to which the first locking members 55 and the second locking members 75 are attached may be the same or different in the first flap 51 and the second flap 71. The numbers of the first locking members 55 and the second locking members 75 in the first flap 51 and the second flap 71 may be the same or different.

[0043] The number of ribs 58 and ribs 78 that the first flap 51 and the second flap 71 have may be different from the number of first locking members 55 and second locking members 75 that the first flap 51 and the second flap 71 have.

[0044] For example, the first flap 51 and the second flap 71 may have the first locking member 55 and the second locking member 75 to which the ribs 58 and 78 are not connected. In this case, the first locking member 55 and the second locking member 75 to which the ribs 58 and 78 are not connected are fixed to the main body 11 by joining the bases (first fixed end 56 and second fixed end 76) of the first locking member 55 and the second locking member 75 to the outer circumferential surface of the main body 11.

[0045] The main body 11 has a first region 30a, a second region 30b, and a third region 30c, each having a different winding pitch of the wire 30. The winding pitch of the wire 30 in the first region 30a is generally uniform, the winding pitch of the wire 30 in the second region 30b is generally uniform, and the winding pitch of the wire 30 in the third region 30c is generally uniform.

[0046] The first region 30a is a region located between the tip 12 of the main body 11 and the first fixed end 56 in the longitudinal direction A. In this embodiment, the tip of the first region 30a is located at the tip 12 of the main body 11.

[0047] By positioning the first region 30a between the tip 12 of the main body 11 and the first fixed end 56, for example, when placing the stent 10 in a bile duct, the position of the tip 12 of the main body 11 can be confirmed by visually observing the tip of the first region 30a under X-ray fluoroscopy.

[0048] The second region 30b is adjacent to the first region 30a in the longitudinal direction A and is provided on the proximal side A2 of the first region 30a.

[0049] The second region 30b is a region in which the number of turns of the wire 30 per unit length is smaller than that of the first region 30a. That is, the second region 30b is a region in which the wire 30 is spirally wound at a winding pitch greater than that of the first region 30a.

[0050] The third region 30c is adjacent to the second region 30b in the longitudinal direction A and is provided on the base end side A2 of the second region 30b.

[0051] The third region 30c is a region where the number of turns of the wire 30 per unit length is smaller than that of the second region 30b. That is, the third region 30c is a region where the wire 30 is spirally wound at a larger winding pitch than that of the second region 30b.

[0052] Therefore, of the first region 30a, the second region 30b, and the third region 30c in the main body 11, the first region 30a has the greatest rigidity and is less likely to deform than the second region 30b and the third region 30c against forces applied in the longitudinal direction A and the radial direction R.

[0053] With respect to the winding angle (inclination) of the wire 30 with respect to the longitudinal axis X1, the winding angle of the wire 30 in the first region 30a is closer to a right angle than the winding angle of the wire 30 in the second region 30b.

[0054] Furthermore, the winding angle of the wire 30 in the second region 30b is closer to a right angle than the winding angle of the wire 30 in the third region 30c.

[0055] The boundary between the first region 30a and the second region 30b is located at the same position as the first fixed end 56 in the longitudinal direction A. The boundary between the first region 30a and the second region 30b does not have to be located at the same position as the first fixed end 56 strictly.

[0056] By positioning the boundary between the first region 30a and the second region 30b at a position corresponding to the first fixed end 56, for example, when placing the stent 10 in a bile duct, the position of the first fixed end 56 can be confirmed by visually checking the boundary between the first region 30a and the second region 30b under X-ray fluoroscopy.

[0057] 3, the distance in the longitudinal direction A from the second fixed end 76 to the base end 13 of the main body 11 is referred to as a first distance L1. Also, the distance in the longitudinal direction A from the boundary between the second region 30b and the third region 30c to the base end 13 of the main body 11 is referred to as a second distance L2.

[0058] The second distance L2 is at least twice the first distance L1. By making the second distance L2 at least twice the first distance L1, the distance in the longitudinal direction A from the boundary between the second region 30b and the third region 30c to the proximal end 13 of the main body 11 can be sufficiently maintained, and when the stent 10 is pulled into the channel of the endoscope, the third region 30c, which has low rigidity, can be reliably folded back and pulled into the channel. The process of pulling the stent 10 into the channel of the endoscope will be described later.

[0059] In this embodiment, the proximal end of the third region 30 c is located at the proximal end 13 of the main body 11 .

[0060] In the longitudinal direction A, the boundary between the second region 30b and the third region 30c is preferably positioned at the center of the stent 10. By positioning the boundary between the second region 30b and the third region 30c at the center of the stent 10, for example, when placing the stent 10 in a bile duct, the position of the center of the stent 10 can be confirmed by visually checking the boundary between the second region 30b and the third region 30c under X-ray fluoroscopy.

[0061] The wire 30 is fixed to the main body 11 by a metal ring 35. The ring 35 is an annular member with the longitudinal axis X1 as its central axis, and is provided at the tip of the first region 30a.

[0062] If the wire 30 can be sufficiently fixed to the main body 11 without the ring 35, the stent 10 does not need to include the ring 35.

[0063] The main body 11 is formed with a first through hole (through hole) 14 and a second through hole (through hole) 15 that penetrate the main body 11 from the inner peripheral surface to the outer peripheral surface.

[0064] In the stent 10 placed in the bile duct, bile can flow from the outer peripheral surface side of the main body 11 into the internal space of the main body 11 through the through-holes 14, 15. The number and positions of the through-holes 14, 15 can be set appropriately. Part or all of the through-holes 14, 15 may overlap with the ribs 58 or 78.

[0065] In the present embodiment, the first through hole 14 is provided on the tip side A1 of the main body 11, and is provided at a position overlapping with the first region 30a in the longitudinal direction A. Specifically, the first through hole 14 is provided on the tip side A1 beyond the first fixed end 56.

[0066] The second through-hole 15 is provided on the base end side A2 of the main body 11, at a position overlapping with the third region 30c in the longitudinal direction A.

[0067] FIG. 4 is a schematic cross-sectional view showing the structure of the stent delivery device 1. As shown in FIG.

[0068] The delivery catheter 100 includes a guide catheter 80 and a pusher catheter 90 .

[0069] The guide catheter 80 has a tube (guide tube) 81 through which a guide wire can be inserted, and a traction section 85 for pulling the tube 81 toward the base end side A2. The guide wire is a long, thin member used when placing the stent 10 in the bile duct.

[0070] The tube 81 is a cylindrical member made of resin, and has an inner cavity through which a guide wire can be inserted. The tube 81 is flexible enough to be deformed when the tube 81 comes into contact with biological tissue during use of the stent delivery device 1.

[0071] The tube 81 is an elastic member having a restoring force, and when no external force is applied, the tube 81 is straight due to the restoring force. The inner peripheral surface 81b of the tube 81 is circular when viewed in a radial cross section of the tube 81.

[0072] The tube 81 has a small diameter portion located on the distal end side A1 and a large diameter portion 83 located on the proximal end side A2. The outer diameter of the large diameter portion 83 is larger than the outer diameter of the small diameter portion .

[0073] The outer circumferential surface of the small diameter portion 82 and the outer circumferential surface of the large diameter portion 83 are connected by a smoothly curved surface. As a result, the outer diameter of the tube 81 gradually increases from the small diameter portion 82 toward the large diameter portion 83.

[0074] The outer diameters of the small diameter portion 82 and the large diameter portion 83 are smaller than the inner diameter of the stent 10. Therefore, the stent 10 can be attached to the tube 81 by inserting the tube 81 into the stent 10.

[0075] In the case where the diameter of the stent 10 is small, the outer diameter of the tube 81 may be constant along the longitudinal direction A.

[0076] The traction unit 85 has a pipe 86, a wire 87, and an operation unit 89. The pipe 86 is a cylindrical member made of metal and open at both ends in the axial direction.

[0077] The pipe 86 is coaxial with the tube 81 and embedded in the wall of the tube 81. The pipe 86 is provided at the base end portion of the large diameter portion 83.

[0078] The wire 87 is a thin, elongated metal member, the tip of which is welded to the pipe 86 and the base of which is connected to the operating section 89 .

[0079] The pusher catheter 90 has a single-lumen tube (second tube) 91, a multi-lumen tube (first tube) 92, and a grip portion 93.

[0080] The single lumen tube 91 is a cylindrical member having an internal space (second lumen) into which the large diameter portion 83 of the tube 81 can enter. The single lumen tube 91 is flexible.

[0081] The surface (distal surface) on the distal side A1 of the single lumen tube 91 is a plane perpendicular to the central axis of the single lumen tube 91. The distal surface of the single lumen tube 91 can abut against the base end of the stent 10 to support the stent 10.

[0082] The thickness of the single lumen tube 91 is greater than the thickness of the main body 11 of the stent 10. The thickness of the single lumen tube 91 refers to the difference in size between the outer diameter and the inner diameter of the single lumen tube 91. The thickness of the main body 11 refers to the difference in size between the outer diameter and the inner diameter of the main body 11.

[0083] The single lumen tube 91 has a length that allows the large diameter portion 83 of the tube 81 to be completely housed inside the single lumen tube 91. The material of the single lumen tube 91 is not particularly limited, but resin is preferable.

[0084] The multi-lumen tube 92 is fixed to the proximal end of the single-lumen tube 91. The multi-lumen tube 92 has a guidewire lumen 92a for inserting a guidewire therethrough, and a wire lumen (first lumen) 92b.

[0085] The guidewire lumen 92a opens at the tip of the multi-lumen tube 92, and opens at the side surface of the multi-lumen tube 92 on the proximal end side A2 of the tip of the multi-lumen tube 92.

[0086] The wire 87 of the guide catheter 80 is inserted through the wire lumen 92b. The wire lumen 92b opens at the distal end and proximal end of the multi-lumen tube 92.

[0087] The grip portion 93 is connected to the base end of the multi-lumen tube 92. The grip portion 93 is a substantially cylindrical member with a larger diameter than the multi-lumen tube 92. The outer peripheral surface of the grip portion 93 may be formed with irregularities or the like to prevent slipping or the like.

[0088] A through-hole (gripping through-hole) 93a communicating with the wire lumen 92b is formed in the gripping portion 93. In this embodiment, the through-hole 93a is located on an extension line of the central axis of the multi-lumen tube 92 extending toward the base end side A2.

[0089] The wire 87 of the guide catheter 80 is inserted through the through-hole 93a. The wire 87 and the operation section 89 connected to the proximal end of the wire 87 extend beyond the through-hole 93a to the proximal side A2.

[0090] The single lumen tube 91 has a hole 91a formed on the outer peripheral surface at the distal end thereof, the hole 91a communicating with the internal space (second lumen) of the single lumen tube 91.

[0091] A thread (connecting member) 95 is threaded through the hole 91a. The thread 95 has an end knotted to form a loop (annular). The looped thread 95 passes through the second through-hole 15 in the main body 11 of the stent 10 from the outside R2 to the inside R1 and enters the inside of the main body 11.

[0092] The tube 81 of the guide catheter 80 is inserted in the longitudinal direction A through the loop of the thread 95 inside the stent 10 .

[0093] Next, the operation when using the stent delivery device 1 will be described.

[0094] Fig. 5 is a diagram showing the process of placing the stent 10 by the stent delivery device 1. Fig. 6 is a diagram showing the placed stent 10.

[0095] First, the surgeon inserts the proximal end of the guide wire protruding from the forceps port of the endoscope into the distal opening of the tube 81 of the stent delivery device 1 to which the stent 10 is attached.

[0096] The guidewire advances from the proximal opening of tube 81 into the second lumen of single lumen tube 91. The surgeon advances the proximal end of the guidewire into guidewire lumen 92a, causing the guidewire to protrude from the proximal opening of guidewire lumen 92a.

[0097] The surgeon inserts the stent delivery device 1 with the guide wire passed through it into the channel of the endoscope, and protrudes the tip of the stent delivery device 1 from the tip of the channel. The surgeon operates the elevator of the endoscope, points the tip of the stent delivery device 1 toward the duodenal papilla, and advances the stent delivery device 1 into the bile duct along the guide wire.

[0098] As shown in FIG. 5, the stent delivery device 1 advances into the bile duct Bd while pushing open the stricture site St in the bile duct Bd.

[0099] At this time, the stent 10 mounted on the stent delivery device 1 advances into the bile duct Bd from the distal end side A1. As described above, in the stent 10, the first region 30a, which has greater rigidity than the second region 30b arranged on the proximal end side A2, is arranged on the distal end side A1.

[0100] Therefore, the stent 10 can expand the stricture site St and advance into the bile duct Bd while maintaining a sufficient space within the bile duct Bd.

[0101] When the stent 10 is advanced into the stricture site St of the bile duct Bd, a force that compresses the stent 10 in the longitudinal direction A acts on the stent 10.

[0102] Since the main body 11 of the stent 10 has the first region 30a, the second region 30b, and the third region 30c, the above-mentioned force acts in a dispersed manner at the boundary between the first region 30a and the second region 30b and the boundary between the second region 30b and the third region 30c, thereby preventing the stent 10 from buckling when placed.

[0103] The surgeon advances the stent 10 into the bile duct Bd until the first flap 51 is positioned further back (tip side A1) than the stenosis site St, and then moves the stent delivery device 1 back and forth to determine the placement position of the stent 10.

[0104] At this time, the surgeon can confirm the tip position of the stent 10 and determine the placement position of the stent 10 by checking the wire 30 provided in the first region 30a located between the tip 12 of the main body 11 and the first fixed end 56 under X-ray fluoroscopy.

[0105] In the stent delivery device 1, as long as the tube 81 is inserted through the loop of the thread 95, the stent 10 will not come off the pusher catheter 90, and therefore the stent 10 can be pulled back by retracting the stent delivery device 1. This allows the surgeon to easily adjust the position of the stent 10.

[0106] After determining the placement position of the stent 10, the surgeon pulls the control unit 89 toward the operator (proximal end side A2) while holding the pusher catheter 90. Pulling the control unit 89 toward the operator causes the wire 87 and the tube 81 to retract. At this time, the stent 10 does not retract because it is in contact with the pusher catheter 90 in the longitudinal direction A.

[0107] When the tube 81 is retracted and removed from the stent 10 and the thread 95, the engagement between the stent 10 and the pusher catheter 90 by the thread 95 is released, and the stent 10 is placed at a predetermined position in the bile duct Bd as shown in FIG.

[0108] After the stent 10 is placed, as shown in Figure 6, the first flap 51 is positioned deep inside the stenosis site St, and the second flap 71 is positioned near the duodenal papilla Dp outside the bile duct Bd, thereby maintaining the placement position of the stent 10 in an optimal manner.

[0109] In the stent 10 placed in the bile duct Bd, the second region 30b and the third region 30c, which have lower rigidity than the first region 30a, are arranged on the proximal side A2 of the first fixed end 56.

[0110] Therefore, the stent 10 is placed in the bile duct Bd in a state where it sufficiently conforms to the shape of the bile duct Bd.

[0111] Next, the operation of retrieving the stent 10 placed in the bile duct Bd through the channel of the endoscope will be described.

[0112] FIG. 7 shows the process of pulling the stent 10 into the channel of the endoscope.

[0113] The surgeon introduces the side-viewing endoscope to the vicinity of the duodenal papilla Dp, protrudes a retrieval tool such as grasping forceps or a snare from the channel, and holds the base end of the stent 10 with the retrieval tool.

[0114] Next, the surgeon retracts the retrieval tool 120 holding the stent 10. As shown in Fig. 7, when the stent 10 reaches the channel tip opening of the side-viewing endoscope (endoscope) 110, the stent 10 is pulled into the channel 111 of the endoscope 110 while being folded back at the site held by the retrieval tool 120.

[0115] At this time, since the distance from the base end 13 of the main body 11 to the boundary between the second region 30b and the third region 30c (second distance L2) is more than twice the distance from the base end 13 of the main body 11 to the second fixed end 76 (first distance L1), the surgeon can easily crush the stent 10 by folding back the third region 30c, which has the least rigidity, and pull it into the channel 111.

[0116] Furthermore, as described above, the width of the rib 78 is smaller than the width of the second locking member 75. Therefore, the volume per unit length of the rib 78 is smaller than the volume per unit length of the second locking member 75. This prevents the rib 78 from hindering the collapse of the third region 30c.

[0117] The medical stent (stent) 10 of this embodiment comprises: a main body 11 having a tubular member (inner layer 20 and outer layer 40) extending in a longitudinal direction A; a reinforcing material (wire) 30 spirally wound around a longitudinal axis X1 extending in the longitudinal direction A, extending in the longitudinal direction A, and embedded between the inner surface of the tubular member and the outer surface of the tubular member; a first locking member 55 having a first fixed end 56 fixed to a distal side A1 of the main body 11 and a first free end 57 located outside R2 from the outer surface of the tubular member, and extending from the first fixed end 56 to the first free end 57 toward the proximal side A2; and a second locking member 75 having a second fixed end 76 fixed to the proximal side A2 of the main body 11 and a second free end 77 located outside R2 from the outer surface of the tubular member, and extending from the second fixed end 76 to the second free end 77 toward the distal side A1. The main body 11 has a first region 30a, a second region 30b, and a third region 30c in which the winding pitches of the reinforcing material 30 are different from one another.

[0118] The first region 30a is a region located between the tip 12 of the main body 11 and the first fixed end 56 in the longitudinal direction A. The second region 30b is located on the base end side A2 of the first region 30a, and is a region where the reinforcing material 30 is spirally wound at a larger winding pitch than the first region 30a. The third region 30c is located on the base end side A2 of the second region 30b, and is a region where the reinforcing material 30 is spirally wound at a larger winding pitch than the second region 30b.

[0119] The stent delivery device 1 of this embodiment comprises a guide catheter 80 having a guide tube (tube) 81 through which a guide wire can be inserted and a wire 87 connected to the guide tube 81, a pusher catheter 90 having a first tube (multi-lumen tube) 92 having a first lumen (wire lumen) 92b through which the wire 87 can be inserted, and a second tube (single-lumen tube) 91 connected to the tip of the first lumen 92b and having a second lumen through which the guide tube 81 can be inserted, a connecting member (thread) 95 having a loop through which the guide tube 81 can be inserted and connected to the tip of the pusher catheter 90, and a stent 10 extending in the longitudinal direction A and positioned on the tip side A1 of the tip of the second tube 91.

[0120] The main body 11 has a through-hole (second through-hole) 15 that penetrates the tubular member from the inner peripheral surface to the outer peripheral surface and is provided on the base end side A2. The loop of the connecting member 95 is inserted through the through-hole 15.

[0121] The guide tube 81 is inserted through the loop of the connecting member 95 , thereby positioning the stent 10 relative to the pusher catheter 90 .

[0122] Therefore, the medical stent 10 and stent delivery device 1 according to this embodiment can provide a medical stent 10 and a stent delivery device 1 that allow the position of the tip 12 to be easily grasped under X-ray fluoroscopy.

[0123] Although one embodiment of the present invention has been described above in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and design modifications and the like are also included within the scope of the present invention. Furthermore, the components shown in the above-described embodiment and the following modified examples can be appropriately combined to form a configuration.

[0124] (Variation 1) In the above embodiment, the base end of the third region 30c is located at the base end 13 of the main body 11, but the aspect of the third region 30c is not limited to this. The base end of the third region 30c may be located, for example, on the distal side A1 of the base end 13 of the main body 11.

[0125] In this case, the main body of the stent is provided with, in order from the distal end side A1, a first region 30a, a second region 30b, a third region 30c, and a region where no wire 30 is provided (fourth region).

[0126] The stiffness of the fourth region where no wire 30 is provided is less than the stiffness of the third region 30c. That is, the main body of the stent has four regions with different stiffnesses.

[0127] Because the main body of the stent has the first region 30a, the second region 30b, the third region 30c, and the fourth region, the force acting on the stent when the stent is advanced into the stricture St of the bile duct Bd is dispersed to the boundary between the first region 30a and the second region 30b, the boundary between the second region 30b and the third region 30c, and the boundary between the third region 30c and the fourth region, thereby effectively preventing the stent from buckling during placement.

[0128] At this time, for example, at least a portion of the rib 78 is located between the base end of the third region 30c and the base end 13 of the main body 11 in the longitudinal direction A. In other words, since the rib 78 is provided in the fourth region where the wire 30 is not provided, the rib 78 can provide a predetermined rigidity.

[0129] (Variation 2) In the above embodiment, the main body 11 has the same outer diameter from the distal end 12 to the proximal end 13, but the form of the main body 11 is not limited to this.

[0130] For example, the main body of the stent may have a tapered portion at the distal end, the outer circumferential surface of which is tapered toward the distal end side A1.

[0131] The reduced diameter portion is provided, for example, closer to the distal end side A1 than the first fixed end 56. In this reduced diameter portion, the inner circumferential surface of the main body of the stent may have a reduced diameter toward the distal end side A1, or a wire (reinforcing material) embedded in the main body may have a reduced diameter toward the distal end side A1.

[0132] The tip of the stent is tapered by the reduced diameter portion, so that when the stent is advanced into the bile duct Bd, the tip of the stent can be easily advanced into the stricture site St. [Explanation of symbols]

[0133] 1. Stent delivery device 10 Medical stents (stents) 11 Main unit 12 Tip of the main body 13 Base end of main body 14 Through hole (first through hole) 15 Through hole (second through hole) 30 Wire (reinforcement) 30a First area 30b Second area 30c third area 35 Ring 55 First locking member 56 First fixed end 57 First free end 75 Second locking member 76 Second fixed end 77 Second free end 78 Rib (joint) 80 Guide Catheter 81 Tube (Guide Tube) 87 Wire 90 Pusher Catheter 91 Single lumen tube (secondary tube) 92 Multi-lumen tube (first tube) 95 Thread (connecting member) A Longitudinal direction A1 Tip side A2 proximal side X1 Longitudinal axis R Radial direction R1 Inside R2 outside

Claims

1. a main body having a tubular member extending in a longitudinal direction, and a reinforcing material spirally wound around a longitudinal axis extending in the longitudinal direction, extending in the longitudinal direction, and embedded between an inner circumferential surface of the tubular member and an outer circumferential surface of the tubular member; a first locking member having a first fixed end fixed to a distal end side in the longitudinal direction of the main body and a first free end located radially outward of the main body relative to the outer circumferential surface of the tubular member, the first locking member extending from the first fixed end to the first free end toward a proximal end side in the longitudinal direction; a second locking member having a second fixed end fixed to the base end side of the main body and a second free end located outside the outer circumferential surface of the tubular member, the second locking member extending from the second fixed end to the second free end toward the tip end; Equipped with the main body has a first region, a second region, and a third region in which the winding pitches of the reinforcing material are different from one another; the first region is a region located between the tip of the main body and the first fixed end in the longitudinal direction, the second region is located on the base end side of the first region, and is a region in which the reinforcing material is spirally wound at a winding pitch greater than that of the first region, the third region is located on the base end side of the second region, and is a region in which the reinforcing material is spirally wound at a winding pitch greater than that of the second region. Medical stents.

2. a boundary between the first region and the second region is provided at approximately the same position as the first fixed end in the longitudinal direction; The medical stent according to claim 1.

3. In the longitudinal direction, a distance from a boundary between the second region and the third region to a base end of the main body is at least twice the distance from the second fixed end to the base end of the main body. The medical stent according to claim 1.

4. The proximal end of the third region is located at the proximal end of the main body. The medical stent according to claim 1.

5. a proximal end of the third region is located closer to the distal end than the proximal end of the main body; The medical stent according to claim 1.

6. a joining portion extending from the second fixed end toward the base end and joined to the outer circumferential surface of the main body; The medical stent according to claim 1.

7. a joining portion extending from the second fixed end toward the base end and joined to the outer circumferential surface of the main body; At least a portion of the joint is located between a proximal end of the third region and a proximal end of the main body in the longitudinal direction. The medical stent according to claim 5.

8. a through hole penetrating the main body from the inner circumferential surface to the outer circumferential surface; The through hole is provided so as to overlap the first region in the longitudinal direction. The medical stent according to claim 1.

9. a circular ring having the longitudinal axis as a central axis, The ring is provided at the tip of the first region and fixes the reinforcement member to the body. The medical stent according to claim 1.

10. The main body has a tapered portion at a tip end, the outer circumferential surface of which tapered toward the tip end. The medical stent according to claim 1.

11. a guide catheter having a guide tube through which a guide wire can be inserted and a wire connected to the guide tube; a pusher catheter including: a first tube having a first lumen through which the wire can be inserted; and a second tube connected to a distal end of the first lumen and having a second lumen through which the guide tube can be inserted; a connecting member having a loop through which the guide tube can be inserted and connected to the distal end of the pusher catheter; a stent extending in a longitudinal direction and positioned distally of the distal end of the second tube in the longitudinal direction; Equipped with The stent is a main body including a tubular member extending in the longitudinal direction and through which the guide tube is inserted, a reinforcing material wound spirally around a longitudinal axis extending in the longitudinal direction and extending in the longitudinal direction, the reinforcing material being embedded between an inner peripheral surface of the tubular member and an outer peripheral surface of the tubular member, and a through hole penetrating the tubular member from the inner peripheral surface to the outer peripheral surface and provided on a base end side in the longitudinal direction; a first locking member having a first fixed end fixed to the distal end side of the main body and a first free end located radially outward of the main body relative to the outer circumferential surface of the tubular member, the first locking member extending from the first fixed end to the first free end toward the proximal end; a second locking member having a second fixed end fixed to the base end side of the main body and a second free end located outside the outer circumferential surface of the tubular member, the second locking member extending from the second fixed end to the second free end toward the tip end; and the main body has a first region, a second region, and a third region in which the winding pitches of the reinforcing material are different from one another; the first region is a region located between the tip of the main body and the first fixed end in the longitudinal direction, the second region is located on the base end side of the first region, and is a region in which the reinforcing material is spirally wound at a winding pitch greater than that of the first region, the third region is located on the base end side of the second region, and is a region in which the reinforcing material is spirally wound at a winding pitch greater than that of the second region, The loop of the connecting member is inserted into the through hole, The guide tube is inserted through the loop, thereby positioning the stent relative to the pusher catheter. Stent delivery device.

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