Medical stent and stent delivery device

Abstract

To provide a medical stent which can be indwelled in a bile duct in a state of sufficiently following the shape of the bile duct, and a stent delivery device.SOLUTION: A medical stent includes a main body including a tubular member extending in a longitudinal direction and a reinforcing material helically wound around a longitudinal axis 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, the main body including a first region and a second region in which winding pitches of the reinforcing material are different from each other, the second region being a region in which the reinforcing material is helically wound at a winding pitch larger than that of the first region, and being longer than the first region in the longitudinal direction.SELECTED DRAWING: Figure 3

Description

[Technical Field]

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

[0002] A known treatment for bile duct strictures is to place a stent in the bile duct. The stent is placed along the bile duct to maintain space within the bile duct. The area of ​​the stent placed in the bile duct that is not at the stricture site needs to conform to the shape of the bile duct.

[0003] When an indwelling stent becomes blocked, etc., it may become necessary to replace the stent. When replacing the stent, the indwelling stent is first removed and retrieved.

[0004] One known method for retrieving a stent is to retrieve the extracted stent through a treatment instrument channel of an endoscope.

[0005] When a stent is retrieved through a treatment channel, the ends of the stent are held with a treatment tool such as a grasping forceps or snare and pulled into the channel. At this time, the ends of the stent may bend and overlap at the site where they are held. When the ends of the stent overlap, the radial dimension increases, so in order to pull the stent into the channel, the overlapped ends must be crushed radially.

[0006] Conventionally, stents having multiple regions with different rigidities have been proposed (for example, Patent Document 1). In a stent having multiple regions with different rigidities, the region with lower rigidity among the multiple regions is arranged on the proximal end side.

[0007] When placing the stent, the region with greater stiffness is positioned at the site of the stricture to maintain sufficient space within the bile duct. When retrieving the stent, the proximal end with less stiffness is crushed to smoothly pull the stent into the channel. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Patent No. 6995219 Summary of the Invention [Problem to be solved by the invention]

[0009] However, in a stent placed in a bile duct, the region with high rigidity may have difficulty conforming to the shape of the bile duct. In particular, if the length of the region with high rigidity is long relative to the overall length of the stent, and there is a stricture in the upper part of the bile duct, the region with high rigidity may be positioned not only at the stricture but also in other areas, which may make it difficult for the stent placed in areas other than the stricture to conform to the shape of the bile duct.

[0010] In view of the above circumstances, an object of the present invention is to provide a medical stent and a stent delivery device that can be placed in a bile duct while sufficiently conforming to the shape of the bile duct. [Means for solving the problem]

[0011] In order to solve the above problems, the present invention proposes the following means. The medical stent of the present invention comprises a main body having a tubular member extending in the 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 surface of the tubular member and the outer surface of the tubular member, and the main body has a first region and a second region in which the winding pitch of the reinforcing material is different from each other, and the second region is a region in which the reinforcing material is spirally wound at a winding pitch greater than that of the first region, and is longer in the longitudinal direction than the first region.

[0012] 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, a tubular member extending in the longitudinal direction and through which the guide tube is inserted, a reinforcing material embedded between the inner peripheral surface and the outer peripheral surface of the tubular member, and a base member extending in the longitudinal direction and extending from the inner peripheral surface to the outer peripheral surface of the tubular member. the reinforcing material extends in the longitudinal direction by being spirally wound around a longitudinal axis extending in the longitudinal direction; the main body has a first region and a second region in which the winding pitch of the reinforcing material is different from each other; the second region is a region in which the reinforcing material is spirally wound at a winding pitch larger than that of the first region, is provided closer to the base end than the first region, and is longer in the longitudinal direction than the first 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 with respect to the pusher catheter. [Effects of the Invention]

[0013] According to the medical stent and stent delivery device of the present invention, it is possible to provide a medical stent and stent delivery device that can be placed in the bile duct in a state that sufficiently conforms to the shape of the bile duct. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is an overall view of a stent delivery device according to a first embodiment. [Figure 2] FIG. 1 is a side view of a stent according to a first embodiment. [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. [Figure 8] FIG. 10 is a perspective view of a stent according to a second embodiment. [Figure 9] FIG. 10 is a perspective view of a stent according to a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0015] (First embodiment) A stent delivery device 1 and a medical stent 10 according to a first embodiment of the present invention will be described with reference to the drawings.

[0016] FIG. 1 is an overall view of a stent delivery device 1 according to the first embodiment. FIG. 2 is a side view of stent 10.

[0017] The stent delivery device 1 includes a medical stent (stent) 10 and a delivery catheter 100.

[0018] 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.

[0019] 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.

[0020] 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.

[0021] 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.

[0022] FIG. 3 is a perspective view of stent 10 with the outer layer of stent 10 visible.

[0023] 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.

[0024] 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.

[0025] The wire 30 is embedded in the main body 11 between the inner and outer circumferential surfaces of the tubular member.

[0026] The main body 11 has, for example, the same outer diameter from the distal end 12 to the proximal end 13 .

[0027] 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.

[0028] 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.

[0029] The wire 30 is made of a material that is radiopaque, such as tungsten steel or stainless steel.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] 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.

[0034] In the first locking member 55, a rib (first rib) 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.

[0035] 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.

[0036] 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.

[0037] 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.

[0038] 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.

[0039] In the second locking member 75, a rib (second rib) 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.

[0040] 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.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] 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.

[0046] The main body 11 has a first region 30a and a second region 30b having different winding pitches for the wire 30. The winding pitch for the wire 30 in the first region 30a is generally uniform, and the winding pitch for the wire 30 in the second region 30b is generally uniform.

[0047] In the longitudinal direction A, the tip of the first region 30a is located at the tip 12 of the main body 11. The second region 30b is adjacent to the first region 30a in the longitudinal direction A and is provided on the base end side A2 of the first region 30a.

[0048] 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.

[0049] Therefore, in the main body 11, the first region 30a has greater rigidity than the second region 30b, and is less likely to deform with respect to forces applied in the longitudinal direction A or the radial direction R than the second region 30b.

[0050] 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.

[0051] The length of the second region 30b is longer than the length of the first region 30a in the longitudinal direction A. In addition, in the longitudinal direction A, the distance from the tip of the first region 30a to the first fixed end 56 is shorter than the distance from the first fixed end 56 to the base end of the first region 30a.

[0052] The boundary between the first region 30a and the second region 30b is located at the same position as the first free end 57 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 free end 57 exactly.

[0053] By positioning the boundary between the first region 30a and the second region 30b at a position corresponding to the first free end 57, for example, when placing the stent 10 in a bile duct, the position of the first free end 57 can be confirmed by visually observing the boundary between the first region 30a and the second region 30b under X-ray fluoroscopy.

[0054] The proximal end of the second region 30b is located at the proximal end 13 of the main body 11. The wire 30 is provided across the main body 11 from the distal end 12 to the proximal end 13.

[0055] 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.

[0056] 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.

[0057] 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 the first rib 58 or the second rib 78.

[0058] 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.

[0059] The second through-hole 15 is provided on the base end side A2 of the main body 11, and is provided at a position overlapping with the second region 30b in the longitudinal direction A.

[0060] FIG. 4 is a schematic cross-sectional view showing the structure of the stent delivery device 1. As shown in FIG.

[0061] The delivery catheter 100 includes a guide catheter 80 and a pusher catheter 90 .

[0062] 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.

[0063] 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.

[0064] 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.

[0065] 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 .

[0066] 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.

[0067] 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.

[0068] 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.

[0069] 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.

[0070] 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.

[0071] 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 .

[0072] The pusher catheter 90 has a single-lumen tube (second tube) 91, a multi-lumen tube (first tube) 92, and a grip portion 93.

[0073] 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.

[0074] 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.

[0075] 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.

[0076] 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.

[0077] 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.

[0078] 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.

[0079] 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.

[0080] 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.

[0081] 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.

[0082] 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.

[0083] 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.

[0084] 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.

[0085] 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 .

[0086] Next, the operation when using the stent delivery device 1 will be described.

[0087] 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.

[0088] 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.

[0089] 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.

[0090] 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.

[0091] 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.

[0092] 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.

[0093] 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.

[0094] 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.

[0095] 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.

[0096] 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.

[0097] 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.

[0098] 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.

[0099] In the stent 10 placed in the bile duct Bd, the second region 30b arranged on the base end side A2 has lower rigidity than the first region 30a and is longer in length in the longitudinal direction A than the first region 30a.

[0100] 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.

[0101] Next, the operation of retrieving the stent 10 placed in the bile duct Bd through the channel of the endoscope will be described.

[0102] FIG. 7 shows the process of pulling the stent 10 into the channel of the endoscope.

[0103] 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.

[0104] 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.

[0105] The portion of the stent 10 that is held by the retriever 120 and that is folded back is the second region 30b located on the proximal side A2. Because the second region 30b, which has lower rigidity than the first region 30a, is folded back, the surgeon can easily crush the stent 10 and pull it into the channel 111.

[0106] In the stent 10, the length of the second region 30b is longer than the length of the first region 30a in the longitudinal direction A. Therefore, when retrieving the stent 10 with the retrieval tool 120, the surgeon can reliably fold back and collapse the second region 30b.

[0107] Furthermore, as described above, the width of the second rib 78 is smaller than the width of the second locking member 75. Therefore, the volume per unit length of the second rib 78 is smaller than the volume per unit length of the second locking member 75. This makes it possible to prevent the second rib 78 from hindering the second region 30b from collapsing.

[0108] 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, and 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 and outer circumferential surfaces of the tubular member. The main body 11 has a first region 30a and a second region 30b in which the winding pitch of the reinforcing material 30 is different from each other.

[0109] The second region 30b is a region in which the reinforcing material 30 is wound spirally at a winding pitch greater than that of the first region 30a, and is longer in the longitudinal direction A than the first region 30a.

[0110] 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 located on the tip side A1 of the tip of the second tube 91.

[0111] A guide tube 81 is inserted through the tubular member of the stent 10 .

[0112] The loop of the connecting member 95 penetrates the tubular member of the stent 10 from the inner peripheral surface to the outer peripheral surface, and is inserted into a through-hole (second through-hole) 15 provided on the base end side A2.

[0113] 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 .

[0114] Therefore, the medical stent 10 and stent delivery device 1 according to this embodiment can provide a medical stent 10 and stent delivery device 1 that can be placed in the bile duct Bd while sufficiently conforming to the shape of the bile duct Bd.

[0115] Second Embodiment A medical stent (stent) 10A according to a second embodiment of the present invention will be described with reference to the drawings.

[0116] In the following description, the same components as those already described will be assigned the same reference numerals and redundant description will be omitted.

[0117] FIG. 8 is a perspective view of a stent 10A according to the second embodiment.

[0118] In the stent 10A, a first region 30Aa, a second region 30Ab, and a third region 30Ac are provided in this order from the distal end side A1.

[0119] The first region 30Aa and the second region 30Ab are regions where the wire 30A is provided. The wire 30A is a coil-shaped member wound in a spiral shape on the outer peripheral surface of the inner layer 20, similar to the wire 30 of the first embodiment.

[0120] The first region 30Aa and the second region 30Ab are regions where the wire 30A is wound at different winding pitches.

[0121] The winding pitch of the wire 30A in the first region 30Aa in this embodiment is the same as the winding pitch of the wire 30 in the first region 30a in the first embodiment.

[0122] Furthermore, the winding pitch of the wire 30A in the second region 30Ab in this embodiment is the same as the winding pitch of the wire 30 in the second region 30b in the first embodiment.

[0123] That is, the second region 30Ab in this embodiment is a region in which the wire 30A is wound at a larger winding pitch than the first region 30Aa.

[0124] The length of the second region 30Ab is longer than the length of the first region 30Aa in the longitudinal direction A. In addition, the base end of the second region 30Ab in this embodiment is located on the distal end side A1 of the base end 13 of the main body 11 in the longitudinal direction A.

[0125] Specifically, the base end of the second region 30Ab is disposed at the same position as the second free end 77 in the longitudinal direction A. The base end of the second region 30Ab does not have to be at the same position as the second free end 77 strictly.

[0126] The third region 30Ac is a region where the wire 30A is not provided. That is, in the stent 10A of this embodiment, the wire 30A is not provided in a region on the proximal side A2 from the second free end 77.

[0127] Therefore, the first region 30Aa has the greatest stiffness and the third region 30Ac has the least stiffness of the stent 10A. The second region 30Ab has a stiffness that is less than that of the first region 30Aa and greater than that of the third region 30Ac.

[0128] When the stent 10A is advanced into the stricture site St of the bile duct Bd, a force that compresses the stent 10A in the longitudinal direction A acts on the stent 10A.

[0129] Because the stent 10A has the first region 30Aa, the second region 30Ab, and the third region 30Ac, the above-mentioned force acts in a dispersed manner at the boundary between the first region 30Aa and the second region 30Ab and the boundary between the second region 30Ab and the third region 30Ac, thereby preventing the stent 10A from buckling during placement.

[0130] In the stent 10A, the second locking members 75 and the ribs 78 are provided in the third region 30Ac, and the second locking members 75 and the ribs 78 can provide a predetermined rigidity.

[0131] Therefore, in the stent 10A, the rigidity of the first region 30Aa, the second region 30Ab, and the third region 30Ac can be gradually changed.

[0132] The medical stent 10A according to this embodiment can be placed in the bile duct Bd in a state where it sufficiently conforms to the shape of the bile duct Bd, and further, buckling of the stent 10A during placement can be suitably prevented.

[0133] (Third embodiment) A medical stent (stent) 10B according to a third embodiment of the present invention will be described with reference to the drawings.

[0134] FIG. 9 is a perspective view of a stent 10B according to the third embodiment.

[0135] In the stent 10B, a first region 30Ba and a second region 30Bb are provided in this order from the distal end side A1.

[0136] The first region 30Ba and the second region 30Bb are regions where the wire 30B is provided. The wire 30B is a coil-shaped member wound in a spiral shape on the outer peripheral surface of the inner layer 20, similar to the wire 30 of the first embodiment.

[0137] The first region 30Ba and the second region 30Bb are regions where the wire 30B is wound at different winding pitches.

[0138] The winding pitch of the first region 30Ba in this embodiment is the same as the winding pitch of the wire 30 in the first region 30a in the first embodiment.

[0139] The winding pitch of the second region 30Bb in this embodiment is the same as the winding pitch of the wire 30 in the second region 30b in the first embodiment.

[0140] That is, the second region 30Bb of this embodiment is a region in which the wire 30B is wound at a larger winding pitch than the first region 30Ba.

[0141] In the longitudinal direction A, the length of the second region 30Bb is longer than the length of the first region 30Ba, and the base end of the second region 30Bb is located at the base end 13 of the main body 11.

[0142] In the stent 10B of this embodiment, the boundary between the first region 30Ba and the second region 30Bb is provided at a position overlapping the first locking member 55 in the longitudinal direction A.

[0143] By positioning the boundary between the first region 30Ba and the second region 30Bb at a position corresponding to the first locking member 55, it is possible to prevent kinking (bending, crushing, etc.) from occurring at the boundary between the first region 30Ba and the second region 30Bb in the stent 10B when the stent 10B is advanced into the bile duct Bd.

[0144] The medical stent 10B of this embodiment can be placed within the bile duct Bd in a state that sufficiently conforms to the shape of the bile duct Bd, and further, can suitably prevent kinking at the boundary between the first region 30Ba and the second region 30Bb when the stent 10B is placed.

[0145] Although the embodiments of the present invention have been described above in detail with reference to the drawings, the specific configuration is not limited to these embodiments and includes design modifications within the scope of the present invention. Furthermore, the components shown in the above-described embodiments and the modified examples shown below can be appropriately combined to form a configuration.

[0146] (Variation 1) In each of the above-described embodiments, 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.

[0147] 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.

[0148] 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.

[0149] 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]

[0150] 1. Stent delivery device 10, 10A, 10B 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, 30A, 30B Wire (reinforcement) 30a, 30Aa, 30Ba First area 30b, 30Ab, 30Bb second 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 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 longitudinally extending tubular member; a reinforcing material that is spirally wound around a longitudinal axis extending in the longitudinal direction, extends in the longitudinal direction, and is embedded between an inner circumferential surface of the tubular member and an outer circumferential surface of the tubular member; a body having the main body has a first region and a second region in which the winding pitch of the reinforcing material is different from each other, The second region is a region in which the reinforcing material is spirally wound at a winding pitch greater than that of the first region, The first region is longer than the first region in the longitudinal direction. Medical stents.

2. 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 medical stent according to claim 1.

3. the first region is provided closer to the tip than the second region, a tip of the first region is located at a tip of the main body, In the longitudinal direction, a distance from the tip of the first region to the first fixed end is shorter than a distance from the first fixed end to a base end of the first region. The medical stent according to claim 2.

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

5. The boundary between the first region and the second region is provided at a position overlapping with the first locking member in the longitudinal direction. The medical stent according to claim 2.

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

7. a base end of the second region is located on a distal end side in the longitudinal direction relative to a base end of the main body; The medical stent according to claim 1.

8. a base end of the second region is located at approximately the same position as the second free end in the longitudinal direction; The medical stent according to claim 2.

9. 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.

10. 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.

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

12. 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 having a main body including a tubular member extending in a longitudinal direction and through which the guide tube is inserted, a reinforcing material 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, the stent being positioned on a distal end side in the longitudinal direction relative to a distal end of the second tube; Equipped with the reinforcing material is wound spirally around a longitudinal axis extending in the longitudinal direction and extends in the longitudinal direction; the main body has a first region and a second region in which the winding pitch of the reinforcing material is different from each other, The second region is a region in which the reinforcing material is spirally wound at a winding pitch greater than that of the first region, The first region is located closer to the base end than the first region. The first region is longer than the first region in the longitudinal direction. 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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