Stent

Abstract

This stent comprises a body that is formed by interweaving wires and has a plurality of entanglement parts where the wires intersect like hooks and are entangled with each other. The body has a cylindrical section and at least one engaging part. Each engaging part is formed by a wire constituting an entanglement part and protrudes from the cylindrical part to the outer circumferential side when the stent expands.

Description

stents

[0001] The technology disclosed herein relates to stents.

[0002] For example, stent placement is used when a narrowed or blocked area (hereinafter simply referred to as "stenosis") occurs in a body lumen (digestive organs such as the bile duct, gallbladder, pancreas, esophagus, duodenum, small intestine, and large intestine, blood vessels, ureters, trachea, etc.) Stent placement is a procedure for securing the lumen by placing a cylindrical stent at the location of the narrowed area or at a position that bypasses the narrowed area.

[0003] Generally, self-expanding stents are used in stent placement. A self-expanding stent is a stent that contracts radially due to its elasticity when a compressive force is applied and expands radially when the compressive force is released. A self-expanding stent is formed, for example, by braiding wires and has multiple entangled portions where the wires cross each other in a hook-like shape and are entangled with each other.

[0004] A self-expanding stent is mounted in a contracted state on a delivery system and transported to the placement site. When released from the delivery system, it self-expands and is placed in that state. If the stent moves out of position (migration) after placement, the function of the stent may be reduced or other problems may occur, so the stent must be able to stably maintain its position once placed.

[0005] In the past, in order to prevent the stent from shifting out of position, a configuration has been proposed in which the wires are not intentionally entangled at some of the multiple entanglement positions on the stent, and instead these parts are bent outward from the tubular part of the stent, thereby providing a locking part with anchor function (see, for example, Patent Document 1).

[0006] International Publication No. 2020 / 194506

[0007] In the above-described conventional stent, the wires are not entangled with each other at some of the positions where the multiple entangled portions are formed, which may result in a decrease in strength and durability.

[0008] This specification discloses a technique that can solve the above-mentioned problems.

[0009] The technology disclosed in this specification can be realized, for example, in the following forms.

[0010] (1) A stent disclosed in this specification includes a main body portion formed by weaving wires and having a plurality of entangled portions in which the wires cross each other in a hook-like shape and entangle with each other. The main body portion has a tubular portion and at least one locking portion. The locking portion is formed by the wires that constitute the entangled portions and protrudes outward from the tubular portion when the stent is expanded.

[0011] In this stent, the main body has locking portions that protrude outward from the tubular portion when the stent is expanded, and the anchoring effect of the locking portions prevents the stent from shifting position after placement. Furthermore, because the locking portions are formed from wires that form entangled portions, this prevents a decrease in the strength and durability of the stent that would otherwise be caused by the provision of locking portions, compared to conventional configurations in which locking portions are provided by deliberately not entangling wires at some of the multiple entanglement formation positions.

[0012] (2) In the stent, the anchoring portion may be configured so that the wires constituting the anchoring portion are positioned in the same imaginary plane. With this configuration, stress concentration on the body wall due to the anchoring portion can be alleviated, and bleeding or perforation in the body wall can be suppressed.

[0013] (3) In the stent, the main body may have a plurality of the locking portions evenly arranged around the tubular portion. This configuration can effectively reduce stress concentration on the body wall due to the locking portions, thereby effectively suppressing bleeding and perforation in the body wall.

[0014] (4) In the above-described stent, the engaging portion may be configured such that the width of the connecting portion with the tubular portion is smaller than the width of the remaining portion. With this configuration, a wide portion of the engaging portion contacts the body wall, effectively reducing stress concentration on the body wall due to the engaging portion, and effectively suppressing bleeding and perforation in the body wall. Furthermore, if the lumen becomes blocked again after the stent is placed, the stent may be removed by pulling on its end. Even in this case, the narrow width of the connecting portion with the tubular portion makes it easier for the engaging portion to flip over and be removed.

[0015] (5) In the stent, the main body may have a plurality of the locking portions connected to the same position on the tubular portion. This configuration can increase the anchoring effect of the locking portions and effectively prevent the stent from shifting after placement.

[0016] (6) In the stent, the wires constituting the plurality of anchoring portions may have different circumferential lengths, which makes it possible to easily and reliably form a cover portion in the area surrounded by the wires constituting the anchoring portions.

[0017] (7) The above stent may further include a resin cover covering at least a portion of the main body, the cover being also disposed in an area surrounded by the wire constituting the engaging portion. This configuration can more effectively mitigate stress concentration on the body wall due to the engaging portion, thereby more effectively suppressing bleeding and perforation in the body wall. Furthermore, it can prevent tumors, granulation tissue, etc. from entering the engaging portion, thereby preventing tumors, granulation tissue, etc. from becoming entangled in the engaging portion when the stent becomes occluded again. As a result, removal can be performed smoothly.

[0018] The techniques disclosed in this specification can be realized in various forms, for example, in the form of a stent, a method for manufacturing or using a stent, etc.

[0019] 1 is a perspective view showing the external configuration of the stent 10 in the first embodiment; FIG. 2 is an explanatory diagram showing the planar configuration of the stent 10 in the first embodiment; FIG. 3 is a development view of the main body portion 100 developed in the circumferential direction D1; FIG. 4 is an explanatory diagram showing a method of weaving the main body portion 100; FIG. 5 is an explanatory diagram showing a method of weaving the main body portion 100; FIG. 6 is an explanatory diagram showing an example of how to use the stent 10 in the first embodiment; FIG. 7 is an explanatory diagram showing the external configuration of the stent 10a in the second embodiment; FIG. 8 is an explanatory diagram showing the external configuration of the stent 10b in the third embodiment;

[0020] A. First Embodiment: A-1. Configuration of Stent 10: FIG. 1 is a perspective view showing the external configuration of stent 10 in the first embodiment, and FIG. 2 is an explanatory diagram showing the planar configuration of stent 10 in the first embodiment. X, Y, and Z axes, which are orthogonal to each other, are shown in FIGS. 1 and 2. In the following description, for convenience, the positive Z-axis direction may be referred to as the upper side, and the negative Z-axis direction may be referred to as the lower side. Furthermore, FIG. 1 shows a state in which the central axis Ax of stent 10 (of a tubular portion 110 described below) is parallel to the Z-axis, but the stent 10 as a whole is configured to be bendable.

[0021] The stent 10 is a medical device that is placed at the location of a stenosis or at a position that bypasses the stenosis when a stenosis occurs in a body lumen (such as the bile duct, gallbladder, pancreas, esophagus, duodenum, small intestine, large intestine, or other digestive organs, blood vessels, ureters, or trachea) to maintain the lumen. The stent 10 is a self-expanding stent that elastically contracts radially when a compressive force is applied and expands radially when the compressive force is released. Figures 1 and 2 show the state of the stent 10 when expanded.

[0022] As shown in Fig. 1, the stent 10 of this embodiment is a so-called covered stent, and includes a main body portion 100 and a cover portion 200. For convenience, the cover portion 200 is shown by a dashed line in Fig. 1, and is not shown in Fig. 2. The cover portion 200 is formed from a resin such as polyurethane or silicone, and covers at least a portion of the main body portion 100. In this embodiment, the cover portion 200 covers substantially the entire main body portion 100.

[0023] The main body 100 is a part that constitutes the framework of the stent 10, and is formed by braiding wires W. The wires W are made of a superelastic alloy, for example, a nickel-titanium (Ni-Ti) alloy. The wires W may be made of other metals, such as stainless steel, tantalum, titanium, a cobalt-chromium alloy, or a magnesium alloy, or may be made of a resin, such as polyolefin, polyester, or a fluororesin. The diameter of the wires W is, for example, about 0.05 mm to 0.5 mm.

[0024] FIG. 3 is a development view of the main body portion 100 developed in the circumferential direction D1. In this specification, the circumferential direction D1 refers to the circumferential direction centered on the central axis Ax of the tubular portion 110 of the main body portion 100, as shown in FIG. 2 . As shown in FIG. 3 , the main body portion 100 is woven using a so-called hook knitting method, in which cells CE, which are approximately diamond-shaped voids surrounded by wires W, are regularly arranged. The main body portion 100 has multiple intersections 102 where the wires W intersect without entangling with each other, and multiple entangled portions 101 where an upwardly convex, approximately V-shaped portion of the wire W and a downwardly convex, approximately V-shaped portion of the wire W intersect with each other in a hook-like manner and entangle with each other. In the entangled portions 101, the upwardly convex portion of the wire W and the downwardly convex portion of the wire W are inseparably connected but movable relative to each other. Therefore, the main body portion 100 can be bent as a whole and can maintain the bent state, allowing it to be easily placed in a curved biological lumen.

[0025] 1 to 3, the main body 100 has a tubular portion 110, a locking portion 120, and a protruding portion 130. The tubular portion 110, the locking portion 120, and the protruding portion 130 that constitute the main body 100 are continuously formed by weaving a single wire W.

[0026] The tubular portion 110 is a portion that expands in diameter to become substantially cylindrical when the stent 10 is expanded. When the stent 10 is expanded, the radius of the tubular portion 110 is, for example, about 2 mm to 40 mm, and the length of the tubular portion 110 along the central axis Ax is, for example, about 20 mm to 200 mm. The radius of the tubular portion 110 is determined appropriately depending on the type, size, position, etc. of the body lumen in which the stent 10 is to be placed.

[0027] The protrusions 130 are generally V-shaped portions formed by a part of the wire W, and protrude upward from the upper end of the tubular portion 110 or protrude downward from the lower end of the tubular portion 110. When the stent 10 is expanded, the protrusions 130 are generally parallel to the central axis Ax of the tubular portion 110. In this embodiment, six upwardly convex protrusions 130 are arranged consecutively in the circumferential direction D1 at the upper end of the tubular portion 110, and six downwardly convex protrusions 130 are arranged consecutively in the circumferential direction D1 at the lower end of the tubular portion 110.

[0028] The locking portions 120 are portions that protrude outward from the tubular portion 110 when the stent 10 is expanded. In this embodiment, two locking portions 120 are arranged discretely and evenly spaced side by side in the circumferential direction D1 near the upper end of the tubular portion 110 (slightly below the upper end). The two locking portions 120 have substantially the same shape and size. Due to the presence of the locking portions 120, when the stent 10 is expanded, the maximum radius of the main body portion 100 (i.e., the distance L3 from the central axis Ax of the tubular portion 110 to the outermost point Pt of the locking portions 120) becomes larger than the radius of the tubular portion 110. The distance L3 is, for example, 4 mm or more and 50 mm or less.

[0029] The locking portion 120 is formed by a portion of the wire W that constitutes the entangled portion 101. More specifically, as shown in Fig. 3, the locking portion 120 is a substantially fan-shaped portion formed by providing a large curved slack to a portion of one of the wires W that constitutes the entangled portion 101 (a portion that is substantially linear in the other entangled portion 101, such as a specific portion SP shown imaginarily by a dashed line in Fig. 3).

[0030] The locking portion 120 is configured so that the wires W constituting the locking portion 120 are positioned within the same imaginary plane. Here, "the wires W constituting the locking portion 120 are positioned within the same imaginary plane" does not necessarily mean that the wires W constituting the locking portion 120 are positioned strictly within the same imaginary plane, but also means that the wires W constituting the locking portion 120 are substantially positioned within the same imaginary plane, specifically, a state in which the distance from any point on the wires W constituting the locking portion 120 to one imaginary plane is 2 mm or less.

[0031] The locking portion 120 is configured to extend obliquely downward from the connection portion with the tubular portion 110 when the stent 10 is expanded. The inclination of the locking portion 120 when the stent 10 is expanded (i.e., the angle between the central axis Ax of the tubular portion 110 and the above-mentioned imaginary plane) is, for example, 20 degrees or more and 70 degrees or less, and more specifically, for example, 30 degrees or more and 60 degrees or less. By configuring the locking portion 120 to extend obliquely downward from the connection portion with the tubular portion 110, the amount of deformation of the locking portion 120 can be reduced when the stent 10 is contracted and stored in a storage device (sheath) that constitutes a delivery system, and the load imposed by the locking portion 120 on the inner wall of the storage device can be reduced.

[0032] As shown in FIGS. 1 and 2 , the locking portion 120 has a generally fan-shaped overall shape when viewed in the direction of the central axis Ax of the tubular portion 110. That is, the locking portion 120 has a shape in which its width increases with increasing distance from the connection portion with the tubular portion 110. Therefore, the width L0 of the connection portion of the locking portion 120 with the tubular portion 110 is smaller than the width L1 of the remaining portion. In this embodiment, the maximum width L1 of the locking portion 120 is greater than the protruding length L2 of the locking portion 120, but this is not limited thereto. For example, it is sufficient if the relationship L1 ≥ 2 / 3L2 is satisfied. Note that in this specification, the width of the locking portion 120 refers to the width along the circumferential direction D1, and the protruding length of the locking portion 120 refers to the protruding length along the above-mentioned imaginary plane. In this embodiment, the locking portion 120 is curved along its entire length and does not have any bent portions. Furthermore, a cover portion 200 is disposed over the entire region 122 surrounded by the wire W that constitutes the locking portion 120.

[0033] A-2. Manufacturing Method of Stent 10: Next, an example of a manufacturing method of the stent 10 of this embodiment will be described. First, the main body 100 is manufactured by hook knitting the wire W. The method of manufacturing a stent by hook knitting is publicly known, as described in Japanese Patent No. 3708923, for example, but will be briefly described below.

[0034] 4 and 5 are explanatory diagrams showing a method for weaving the main body 100. Each column of Figures 4 and 5 shows, in the form of a development, the procedure for producing the main body 100 by weaving the wire W using a jig JG having a plurality of pins PN erected on the outer circumferential surface of a cylindrical member. Hereinafter, the distance between two diagonally adjacent pins PN on the jig JG is referred to as the diagonal distance LP.

[0035] 4A, an end of the wire W is fixed to a pin PN at a predetermined position of the jig JG to set the starting point ST, and the wire W is then hung in a zigzag pattern between the pins PN from the starting point ST. More specifically, the wire W is extended from the starting point ST diagonally upward and left to hang it above the pin PN, then the wire W is extended diagonally downward and left by 1×LP to hang it below the pin PN, and then the wire W is extended diagonally upward and left by 2×LP to hang it above the pin PN. This operation is repeated until the wire W reaches a position corresponding to the upper end of the cylindrical portion 110.

[0036] Next, as shown in section B of FIG. 4 , following the formation of the wire W in section A of FIG. 4 , the wire W is hung between the pins PN in a zigzag pattern so as to form six upwardly convex V-shaped portions (protrusions 130) from a position corresponding to the upper end of the cylindrical portion 110. More specifically, the six protrusions 130 are formed by extending the wire W diagonally upward and left by 1×LP and hanging it above the pins PN, and then extending the wire W diagonally downward and left by 1×LP and hanging it below the pins PN. At this time, at the positions of the pins PN where the wire W is already wound, the wires W cross each other in a hook-like manner, forming entanglement portions 101. This also applies to subsequent processes. At positions where the wire W passes obliquely without being wound around the pins PN, the wires W cross each other without entangling, forming intersection portions 102. This also applies to subsequent processes.

[0037] Next, as shown in column C of Fig. 4, following the formation of the wire W in column B of Fig. 4, the wire W is laid between the pins PN in a zigzag pattern so as to form four downwardly convex V-shaped portions. More specifically, the operation of extending the wire W diagonally downward and left by 1 x LP to lay it below the pin PN, and the operation of extending the wire W diagonally upward and left by 1 x LP to lay it above the pin PN are repeated four times. Thereafter, the wire W is extended diagonally downward and left by 2 x LP.

[0038] Next, as shown in section D of Fig. 5, following the formation of the wire W in section C of Fig. 4, the same operation as in section C of Fig. 4 is repeated until the wire W reaches a position corresponding to the lower end of the tubular portion 110. However, at the position where the locking portion 120 is to be formed, the locking portion 120 before processing is formed. More specifically, at the position where the locking portion 120 is to be formed, the portion of the wire W that constitutes the entangled portion 101 is given slack and is hung on the pin PN so as to form a roughly fan shape. Section E of Fig. 5 shows the state where the wire W reaches a position corresponding to the lower end of the tubular portion 110 after two locking portions 120 before processing are formed.

[0039] Next, as shown in section F of Figure 5, following the formation of the wire W in section E of Figure 5, the wire W is zigzag-hung between the pins PN to form six downwardly convex V-shaped portions (protrusions 130). That is, the protrusions 130 are formed by extending the wire W diagonally downward and left by 1 x LP to hook it under the pin PN, and then extending the wire W diagonally upward and left by 1 x LP to hook it over the pin PN. After forming the sixth protrusion 130, the wire W is extended to the starting point ST, and both ends of the wire W are connected at the starting point ST by, for example, crimping to form the crimped portion 114. Through the above steps, the main body 100 before the processing of the locking portion 120 is produced.

[0040] Next, using, for example, a disk-shaped mold, the unprocessed locking portion 120 is fixed in a raised state so as to protrude from the cylindrical portion 110 toward the outer periphery, and a heat treatment for shape memory (for example, at 350 to 600°C for 5 to 30 minutes) is performed. This forms the locking portion 120 that protrudes from the cylindrical portion 110 toward the outer periphery when expanded.

[0041] Finally, the cover portion 200 is formed at a predetermined location on the main body portion 100. Through the above steps, the manufacturing of the stent 10 of this embodiment is completed.

[0042] A-3. Method of Using the Stent 10: Next, an example of a method of using the stent 10 will be described. Figure 6 is an explanatory diagram showing an example of a method of using the stent 10 of the first embodiment. Note that part of the wire W is not shown in Figure 6.

[0043] First, the stent 10 is mounted on a delivery system in a contracted state. When the stent 10 is in the contracted state, the anchoring portions 120 are folded so as not to protrude radially outward from the tubular portion 110. Next, the delivery system transports the stent 10 to an indwelling position (the position of the stenosis or a position bypassing the stenosis) within the biological lumen 20 shown in FIG. 6 , and the stent 10 is released from the delivery system at the indwelling position. Accordingly, the stent 10 expands due to its self-expanding properties. When the stent 10 expands, each anchoring portion 120 protrudes radially outward from the tubular portion 110. Therefore, as shown in column A of FIG. 6 , the anchoring portions 120 contact the body wall 21 of the biological lumen 20, functioning as anchors and preventing the stent 10 from migrating. As described above, the engaging portion 120 is generally fan-shaped when viewed in the direction of the central axis Ax of the tubular portion 110, so that a wide portion of the engaging portion 120 comes into contact with the body wall 21, which reduces stress concentration on the body wall 21 and suppresses bleeding and perforation in the body wall 21.

[0044] Furthermore, the locking portion 120 is oriented so as to extend obliquely downward from the connection portion with the tubular portion 110. Therefore, as shown in column B of Fig. 6 , when a downward force acts on the stent 10, the locking portion 120 changes angle with the connection portion with the tubular portion 110 as a fulcrum, increasing the inclination of the locking portion 120 relative to the tubular portion 110. As a result, the outer diameter of the stent 10 becomes even larger, the anchor function of the locking portion 120 is enhanced, and displacement of the stent 10 is more effectively suppressed.

[0045] Furthermore, if the stent 10 becomes blocked again by a tumor, granulation tissue, or the like, and a downward force acts on the stent 10 when the stent 10 is being removed, the narrowed width of the connecting portion of the locking portion 120 makes it more likely to flip upward. This reduces the anchor of the locking portion 120. As a result, the stent 10 can be easily removed.

[0046] A-4. Effects of the First Embodiment: As described above, the stent 10 of this embodiment includes a main body portion 100. The main body portion 100 is formed by weaving wires W, and has a plurality of entangled portions 101 in which the wires W cross each other in a hook-like shape and entangle with each other. The main body portion 100 has a tubular portion 110 and an engaging portion 120. The engaging portion 120 is formed from the wires W that constitute the entangled portion 101, and protrudes outward from the tubular portion 110 when the stent 10 is expanded.

[0047] As described above, in the stent 10 of this embodiment, the main body 100 has the locking portions 120 that protrude outward from the tubular portion 110 when the stent 10 is expanded, and therefore the anchor effect of the locking portions 120 can prevent the stent 10 from shifting position after placement. Furthermore, because the locking portions 120 are formed from the wires W that constitute the entangled portions 101, a decrease in strength and durability of the stent 10 due to the provision of the locking portions 120 can be prevented compared to conventional configurations in which locking portions are provided by deliberately not entangling the wires W at some of the multiple entanglement portion formation positions.

[0048] Furthermore, in the stent 10 of this embodiment, the tubular portion 110 and the locking portion 120 that constitute the main body portion 100 are continuously formed by weaving a single wire W, so no joining member is required to join the tubular portion 110 and the locking portion 120, and the diameter of the stent 10 can be reduced when it is contracted.

[0049] Furthermore, in the stent 10 of this embodiment, the anchoring portion 120 is configured so that the wires W constituting the anchoring portion 120 are positioned in the same imaginary plane. Therefore, according to the stent 10 of this embodiment, stress concentration on the body wall 21 due to the anchoring portion 120 can be alleviated, and bleeding and perforation in the body wall 21 can be suppressed.

[0050] Furthermore, in the stent 10 of this embodiment, the main body 100 has a plurality of locking portions 120 that are evenly arranged along the circumferential direction D1 of the tubular portion 110. Therefore, according to the stent 10 of this embodiment, stress concentration on the body wall 21 due to the locking portions 120 can be effectively alleviated, and the occurrence of bleeding or perforation in the body wall 21 can be effectively suppressed.

[0051] Furthermore, in stent 10 of this embodiment, engaging portion 120 has a shape in which width L0 of the connecting portion with tubular portion 110 is smaller than width L1 of the other portion. Therefore, according to stent 10 of this embodiment, a wide portion of engaging portion 120 comes into contact with body wall 21, which effectively alleviates stress concentration on body wall 21 due to engaging portion 120 and effectively suppresses bleeding and perforation in body wall 21. Furthermore, if stent 10 becomes occluded again, pulling on the end of stent 10 will make engaging portion 120 more likely to invert because the connecting portion of engaging portion 120 has a small width, making it easier to remove.

[0052] The stent 10 of this embodiment also includes a resin cover 200 that covers at least a portion of the main body 100. The cover 200 is also disposed in the region 122 surrounded by the wire W that constitutes the engaging portion 120. Therefore, according to the stent 10 of this embodiment, it is possible to more effectively alleviate the concentration of stress on the body wall 21 caused by the engaging portion 120, and more effectively suppress the occurrence of bleeding or perforation in the body wall 21. Furthermore, the cover 200 can prevent tumors, granulation tissue, etc. from entering the engaging portion 120, facilitating the removal operation.

[0053] B. Second Embodiment: Figure 7 is an explanatory diagram showing the external configuration of a stent 10a in a second embodiment. In the following, among the configurations of the stent 10a of the second embodiment, the same configurations as those of the stent 10 of the first embodiment described above are denoted by the same reference numerals, and the description thereof will be omitted as appropriate.

[0054] The stent 10a of the second embodiment differs from the stent 10 of the first embodiment in the configuration of the locking portion 120. Specifically, in the stent 10a of the second embodiment, the locking portion 120 is generally spoon-shaped as a whole when viewed in the direction of the central axis Ax of the tubular portion 110. That is, the locking portion 120 has a shape such that the width increases with increasing distance from the connection portion with the tubular portion 110, and then decreases with increasing distance from the connection portion with the tubular portion 110. In the stent 10a of the second embodiment, the width L0 of the connection portion with the tubular portion 110 in the locking portion 120 is also smaller than the width L1 of the other portions. Furthermore, in the stent 10a of the second embodiment, the maximum width L1 of the locking portion 120 is smaller than the protruding length L2 of the locking portion 120. A stent 10a having such a configuration can be produced by applying the manufacturing method of the stent 10 of the first embodiment described above (see column D in Figure 5) by providing slack in the portion of the wire W that constitutes the entangled portion 101 and hanging it on a pin PN so that it becomes roughly spoon-shaped.

[0055] In the second embodiment of the stent 10a, as in the first embodiment, the main body 100 has an engaging portion 120 formed by the wire W that constitutes the entanglement portion 101, so that the engaging portion 120 can prevent the stent 10a from shifting position after placement, while also preventing a decrease in strength and durability of the stent 10a due to the provision of the engaging portion 120.

[0056] C. Third Embodiment: Figure 8 is an explanatory diagram showing the external configuration of a stent 10b in a third embodiment. In the following, among the configurations of the stent 10b of the third embodiment, the same configurations as those of the stent 10a of the second embodiment described above are denoted by the same reference numerals, and the description thereof will be omitted as appropriate.

[0057] The stent 10b of the third embodiment differs from the stent 10a of the second embodiment in the configuration of the locking portion 120. Specifically, in the stent 10b of the third embodiment, like the second embodiment, the locking portions 120 are formed at two positions on the tubular portion 110, but the locking portions 120 are formed double at each position. That is, the main body 100 of the stent 10 has multiple locking portions 120 connected to the same position on the tubular portion 110. In the stent 10b of the third embodiment, the circumferential lengths of the wires W of the multiple locking portions 120 connected to the same position on the tubular portion 110 are approximately the same. The stent 10b having such a configuration can be produced by the manufacturing method of the stent 10a of the second embodiment described above, by providing slack in the portion of the wire W that constitutes the entangled portion 101 and hanging it on the pin PN so as to form a double, approximately spoon-shaped configuration.

[0058] In the third embodiment of the stent 10b, as in the second embodiment, the main body 100 has an engaging portion 120 formed by the wire W that constitutes the entanglement portion 101, so that the engaging portion 120 can prevent the stent 10b from shifting position after placement, while also preventing a decrease in strength and durability of the stent 10b due to the provision of the engaging portion 120.

[0059] Furthermore, in the third embodiment of the stent 10b, the main body 100 of the stent 10b has multiple engaging portions 120 connected to the same position in the tubular portion 110, thereby increasing the anchor effect of the engaging portions 120 and effectively suppressing displacement of the stent 10b after placement.

[0060] D. Fourth Embodiment: Fig. 9 is an explanatory diagram showing the external configuration of a stent 10c according to a fourth embodiment. In the following, among the configuration of the stent 10c of the fourth embodiment, the same configuration as that of the stent 10b of the third embodiment described above will be denoted by the same reference numerals, and the description thereof will be omitted as appropriate.

[0061] The stent 10c of the fourth embodiment differs from the stent 10b of the third embodiment in the configuration of the locking portion 120. Specifically, in the stent 10c of the fourth embodiment, as in the third embodiment, the main body portion 100 of the stent 10c has a plurality (two) locking portions 120 connected to the same position on the tubular portion 110, but the circumferential lengths of the wires W constituting each of these locking portions 120 are different from each other. That is, one locking portion 120 is disposed in a region 122 surrounded by the wires W constituting the other locking portion 120. In this embodiment, the wires W constituting each of the two locking portions 120 connected to the same position on the tubular portion 110 are located in the same imaginary plane. A stent 10 having such a configuration can be fabricated by providing slack in the portion of the wire W constituting the entangled portion 101 and hanging it on the pins PN so that the two locking portions 120 are roughly spoon-shaped and have different sizes.

[0062] In the stent 10c of the fourth embodiment, as in the third embodiment, the main body 100 has the locking portions 120 formed by the wire W that constitutes the entanglement portion 101, and therefore the locking portions 120 suppress displacement of the stent 10c after placement, while suppressing a decrease in the strength and durability of the stent 10c that would be caused by providing the locking portions 120. Furthermore, in the stent 10c of the fourth embodiment, as in the third embodiment, the main body 100 of the stent 10c has multiple locking portions 120 connected to the same position on the tubular portion 110, and therefore the anchor effect of the locking portions 120 can be increased, and displacement of the stent 10c after placement can be effectively suppressed.

[0063] Furthermore, in the stent 10c of the fourth embodiment, the wires W constituting each of the multiple locking portions 120 connected to the same position on the tubular portion 110 have different circumferential lengths, so that the cover portion 200 can be easily and reliably formed in the region 122 surrounded by the wires W constituting the locking portions 120. Therefore, for example, it is possible to reduce the thickness of the cover portion 200 formed in the region 122.

[0064] E. Modifications: The technology disclosed in this specification is not limited to the above-described embodiment, and can be modified in various forms without departing from the spirit of the invention. For example, the following modifications are also possible.

[0065] The configuration of the stent 10 in the above embodiment is merely an example and can be modified in various ways. For example, the shape of the locking portion 120 is not limited to a generally fan-shaped or generally spoon-shaped configuration, and any shape can be adopted. Furthermore, the wires W constituting the locking portion 120 do not have to be located in the same imaginary plane. Furthermore, the positions and number of the locking portions 120 formed in the tubular portion 110 can be changed as desired. Furthermore, the number of locking portions 120 formed in the same position in the tubular portion 110 can be changed as desired. Furthermore, the main body portion 100 does not need to have a protrusion 130. Furthermore, when multiple locking portions 120 are provided, it is desirable that these locking portions 120 have the same shape.

[0066] The manufacturing method of the stent 10 in the above embodiment is merely an example and can be modified in various ways. For example, in the above embodiment, when the main body portion 100 is produced by hook knitting, six V-shaped portions are knitted in the circumferential direction D1, but the number of V-shaped portions lined up in the circumferential direction D1 may be five or less, or seven or more. Furthermore, the technology disclosed in this specification is not limited to stents produced by hook knitting, but is also applicable to stents produced by other knitting methods (e.g., cross knitting). Furthermore, the knitting method of the main body portion 100 does not need to be entirely hook knitting, as long as it includes hook knitting in part.

[0067] In the above embodiment, the stent 10 is a covered stent having a cover portion 200, but the technology disclosed in this specification is similarly applicable to an uncovered stent that does not have a cover portion 200.

[0068] 10: Stent 20: Biological lumen 21: Body wall 100: Main body portion 101: Tangled portion 102: Intersecting portion 110: Cylindrical portion 114: Crimped portion 120: Locking portion 122: Region 130: Protruding portion 200: Cover portion Ax: Central axis CE: Cell JG: Jig PN: Pin W: Wire

Claims

1. The wire harness has a main body portion formed by weaving wires, the main body portion having a plurality of entangled portions in which the wires cross each other in a hook-like shape and are entangled with each other, The main body portion is A cylindrical portion; at least one locking portion formed by the wire constituting the entangled portion and protruding from the tubular portion to the outer circumferential side when the stent is expanded; A stent having:

2. 10. The stent of claim 1, The stent is configured such that the wires constituting the anchoring portion are positioned within the same imaginary plane.

3. 3. The stent according to claim 1 or claim 2, The main body portion has a plurality of the engaging portions arranged evenly along the circumferential direction of the tubular portion.

4. 3. The stent according to claim 1 or claim 2, The engaging portion has a shape in which the width of the connecting portion with the tubular portion is smaller than the width of other portions.

5. 3. The stent according to claim 1 or claim 2, A stent, wherein the main body portion has a plurality of the engaging portions connected to the same position on the tubular portion.

6. 6. The stent of claim 5, A stent, wherein the circumferential lengths of the wires constituting the plurality of engaging portions are different from each other.

7. 3. The stent according to claim 1 or claim 2, further comprising: a resin cover portion that covers at least a portion of the main body portion, A stent, wherein the cover portion is also disposed in an area surrounded by the wire that constitutes the engaging portion.