Manufacturing method of covered stent and covered stent

Abstract

A method for manufacturing a covered stent includes: disposing an inner covering film (3) on the inside of a stent main body having a mesh structure formed by weaving a wire member, the stent main body having a hooking portion (2b) in which two bent portions of the wire member are hooked to each other; an outer covering film (4) is arranged on the outer side of the stent main body; a relaxation section (6) that bulges in the radial direction of the stent main body is formed on at least one of the membranes (3, 4), and the relaxation section (6) imparts relaxation to at least one of the membranes (3, 4) that permits movement of the two curved sections in the longitudinal direction and the radial direction of the stent main body; and joining the films (3, 4) to each other in the region of the inside of the meshes of the mesh structure.

Description

Technical Field

[0001] The invention relates to a manufacturing method of a coated stent and the coated stent. Background Art

[0002] Conventionally, there is known a stent graft that is arranged in a narrow part of a lumen to relieve stenosis (see, for example, Patent Documents 1 and 2). The stent graft has a coating that covers at least one of the inside and outside of a tubular stent body. The coating prevents tissue from infiltrating into the inside of the stent placed in the lumen.

[0003] In the stent graft of Patent Document 1, the inner and outer grafts are bonded to the mesh portion of the mesh stent body, thereby preventing the graft from twisting when the stent body is expanded, and the inner and outer grafts can be bent together with the stent body.

[0004] In the stent graft of Patent Document 2, a plurality of bonding portions formed by bonding the inner and outer coatings are spaced apart from each other, and a pocket portion that allows movement of the stent body is formed between adjacent bonding portions. Thus, the stent graft can be compressed in the radial direction with very little force.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Publication No. 2005-52419

[0008] Patent Document 2: Japanese Patent No. 4592953 Summary of the invention

[0009] Problem that the invention aims to solve

[0010] The stent is preferably easy to bend along the shape of the lumen and does not apply a load to the tube wall, so the axial force of the stent is required to be low. The axial force is the force that the bent stent wants to restore to a straight shape. The stent body having a hooking portion formed by two curved portions of a wire member being wound around each other achieves high flexibility and low axial force through the three-dimensional relative displacement of the two curved portions when bending. In the case of the coated stents of Patent Documents 1 and 2, since the coating hinders the three-dimensional displacement of the two curved portions, the flexibility is reduced and the axial force is increased compared to the case without the coating.

[0011] The present invention has been made in view of the above-mentioned situation, and an object of the present invention is to provide a method for manufacturing a stent graft and a stent graft that can achieve low axial force.

[0012] Solutions for solving problems

[0013] A technical solution of the present invention is a method for manufacturing a coated stent, wherein the manufacturing method includes the following operations: configuring an inner coating on the inner side of a stent body of a grid structure formed by a braided wire member, the stent body having a hooking portion formed by two bent portions of the wire member hooking with each other; configuring an outer coating on the outer side of the stent body; forming a slack portion bulging along the radial direction of the stent body in at least one of the inner coating and the outer coating, the slack portion providing slack to at least one of the inner coating and the outer coating that allows the two bent portions to move in the length direction and the radial direction of the stent body; and joining the inner coating and the outer coating to each other in the area on the inner side of the mesh of the grid structure.

[0014] Another technical solution of the present invention is a coated stent, wherein the coated stent includes: a stent body, which is a grid structure formed by weaving wire members, the stent body having a hooking portion formed by two bent portions of the wire members hooking each other; an inner coating, which covers the inner side of the stent body; and an outer coating, which covers the outer side of the stent body, at least one of the inner coating and the outer coating having a slack portion bulging along the radial direction of the stent body, the slack portion giving slack to at least one of the inner coating and the outer coating to allow the two bent portions to move in the length direction and the radial direction of the stent body, the inner coating and the outer coating are joined to each other in the area inside the mesh of the grid structure.

[0015] Another technical solution of the present invention is a method for manufacturing a coated stent, wherein a coating made of ePTFE is arranged on at least one of the inner and outer sides of the stent body in a direction where the stretching direction of the ePTFE is consistent with the stretching direction of the stent body when it is radially contracted, the coating is partially connected to the stent body, and the coating is stretched by contracting the stent body radially, thereby generating relaxation in the coating.

[0016] Another technical solution of the present invention is a coated stent, wherein the coated stent includes: a stent body; and a coating made of ePTFE, which covers at least one of the inner side and the outer side of the stent body and is partially connected to the stent body, and the coating is arranged in a direction where the stretching direction of the ePTFE is consistent with the stretching direction of the stent body when it is radially contracted, and the coating is loose in the length direction of the stent body when the stent body is in the state of radial expansion.

[0017] Effects of the Invention

[0018] According to the present invention, there is an effect that a low axial force of the stent graft can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a side view of the stent graft according to the first embodiment of the present invention.

[0020] Figure 2A It is a partial enlarged top view of the bracket body.

[0021] Figure 2B It is along the stent graft Figure 2A Cross-sectional view of line I-I.

[0022] Figure 3 The diagrams are for explaining the shapes of a stent body, an inner coating, and an outer coating of a linear stent graft.

[0023] Figure 4 The diagrams are for explaining the shapes of a stent body, an inner coating, and an outer coating of a curved stent graft.

[0024] Figure 5 This is a flow chart of a method for manufacturing a stent graft according to a first embodiment of the present invention.

[0025] Figure 6 It means in Figure 5 Diagram of a mandrel used in the manufacturing method.

[0026] Figure 7 Yes Description Figure 5 FIG. 5 is a diagram of steps SA1 to SA5 of a manufacturing method.

[0027] Fig. 8A It is a diagram showing a modified example of the recessed portion.

[0028] Figure 8B Yes means Fig. 8A A cross-sectional view of the stent graft in a state where the recess is compressed.

[0029] Fig. 9A It is a diagram showing another modified example of the recessed portion.

[0030] Fig. 9B Yes means Fig. 9A A cross-sectional view of the stent graft in a state where the recess is compressed.

[0031] Fig.10 This is a flow chart of a method for manufacturing a stent graft according to a second embodiment of the present invention.

[0032] Fig.11 Yes Description Fig.10 FIG. 5 is a diagram of steps SB1 to SB5 of a manufacturing method.

[0033] Fig. 12A It is a partially enlarged plan view of the stent body, showing an example of a joint portion.

[0034] Fig. 12B It is a partially enlarged plan view of the stent body showing another example of the joining portion.

[0035] Fig.13 yes Fig.10 Flowchart of the first variant of the manufacturing method.

[0036] Fig.14 Yes Description Fig.13 FIG. 5 is a diagram of steps SB1 to SB5 of a manufacturing method.

[0037] Fig.15 yes Fig.10 Flowchart of the second variant of the manufacturing method.

[0038] Fig.16 Yes Description Fig.15 FIG. 4 is a diagram of step SB45 of the manufacturing method.

[0039] Fig.17 yes Fig.10 Flowchart of the third variant of the manufacturing method.

[0040] Fig.18 Yes Description Fig.17 FIG. 5 is a diagram of steps SB1 to SB5 of a manufacturing method.

[0041] Fig.19 This is a flow chart of a method for manufacturing a stent graft according to a third embodiment of the present invention.

[0042] Fig. 20 It means in Fig.19 Diagram of the mandrel used in the manufacturing method.

[0043] Fig.21 Yes Description Fig.19 FIG. 5 is a diagram of steps SC1 to SC4 of a manufacturing method.

[0044] Fig. 22 This is a flow chart of a method for manufacturing a stent graft according to a fourth embodiment of the present invention.

[0045] Fig.23A It means in Fig. 22 Figure 2 is a diagram of a mandrel and a jig used in the manufacturing method.

[0046] Fig. 23B It means it is composed of two halves. Fig.23A Figure 2 is a diagram of an example of a jig.

[0047] Fig.23C It means it is composed of two halves. Fig.23A Figure 2 shows other examples of the jig.

[0048] Fig.24 Yes Description Fig. 22 FIG. 5 is a diagram of steps SD1 to SD6 of a manufacturing method.

[0049] Fig.25A This is a perspective view of a jig used in the method for manufacturing a stent graft according to the fifth embodiment of the present invention.

[0050] Fig.25B yes Fig.25A A three-dimensional diagram of a modified example of the jig.

[0051] Fig.26A This is a diagram for explaining step SD5.

[0052] Fig.26B This is a diagram for explaining step SD5.

[0053] Fig.27A It is a diagram showing another modified example of the recessed portion.

[0054] Fig.27B It is a diagram showing another modified example of the recessed portion.

[0055] Fig.28A It is a side view of a stent graft according to a sixth embodiment of the present invention.

[0056] Fig.28B Yes means Fig.28A Side view of the stent graft in the contracted state.

[0057] Fig.29 This is a flow chart of a method for manufacturing a stent graft according to a sixth embodiment of the present invention.

[0058] Fig.30 Yes Description Fig.29 FIG. 1 is a diagram of step SE1 of the manufacturing method.

[0059] Fig.31 Yes Description Fig.29 FIG. 5 is a diagram of steps SE2 to SE6 of a manufacturing method.

[0060] Fig.32 It is a side view of the stent graft according to the seventh embodiment of the present invention.

[0061] Fig.33 This is a flow chart of a method for manufacturing a stent graft according to a seventh embodiment of the present invention.

[0062] Fig.34 Yes Description Fig.33 FIG. 5 is a diagram of steps SF2 to SF6 of a manufacturing method.

[0063] Fig.35 It is a side view of a modified example of the stent graft according to the sixth and seventh embodiments. DETAILED DESCRIPTION

[0064] (First embodiment)

[0065] A method for manufacturing a stent graft and a stent graft according to a first embodiment of the present invention will be described with reference to the drawings.

[0066] like Figure 1 As shown, the stent graft 1 of this embodiment includes a tubular stent body 2 , a tubular inner coating 3 covering the inside of the stent body 2 , and a tubular outer coating 4 covering the outside of the stent body 2 .

[0067] The stent body 2 is formed by bending one or more wire members 2a into a zigzag shape and weaving them around the central axis, and has a grid structure with many rhombus-shaped meshes arranged in the circumferential direction and the longitudinal direction. The stent body 2 can shrink in the radial direction. The coated stent 1 is carried on the delivery system in a contracted state, transported into the body cavity by the delivery system, and expanded radially in the body cavity.

[0068] like Figure 2A As shown, the stent body 2 has a hooking portion 2b formed by two curved portions 2c and 2d of the wire member 2a hooking each other in the length direction of the stent body 2. One curved portion 2c is a mountain portion that bends toward one end of the stent body 2 and protrudes toward the other end. The other curved portion 2d is a valley portion that bends toward the other end of the stent body 2 and protrudes toward one end. The sawtooth-shaped wire member 2a has the mountain portions 2c and the valley portions 2d that are alternately arranged in the circumferential direction. The hooking portion 2b is formed by the mountain portions 2c of one row hooking with the valley portions 2d of another adjacent row.

[0069] Thus, the two curved portions 2c and 2d are connected to each other in a freely displaceable manner in the longitudinal direction and radial direction. The stent body 2 can be easily bent without generating axial force, or almost without generating axial force, by three-dimensional displacement of the curved portions 2c and 2d of the hooking portion 2b.

[0070] The inner film 3 and the outer film 4 are sheets made of ePTFE (Expanded polytetrafluoroethylene). The materials of the films 3 and 4 may also be other materials that are biocompatible and flexible and are commonly used for stents, such as silicon. The inner film 3 and the outer film 4 are joined to each other at a part of the inner area of ​​the mesh, namely, a joint 5, and are separated from each other at parts other than the joint 5.

[0071] like Figure 2BAs shown, the inner film 3 has a plurality of slack portions 6 arranged at intervals in the longitudinal direction. Each slack portion 6 is formed by a concave portion extending over the entire circumference of the inner film 3 and bulging inward in the radial direction, for example, a U-shaped groove having a rectangular cross-sectional shape in a longitudinal section in the longitudinal direction. A portion of the hooking portion 2b is disposed between the slack portion 6 and the outer film 4.

[0072] The slack portion 6 forms a space between the inner coating 3 and the outer coating 4, and further provides slack to the inner coating 3. The inner coating 3 having slack can be deformed freely according to external force, allowing the longitudinal and radial movement of a pair of curved portions 2c and 2d forming the hooking portion 2b. Therefore, the movable area of ​​the curved portions 2c and 2d of the hooking portion 2b is increased, and the coatings 3 and 4 can be prevented from hindering the three-dimensional displacement of the curved portions 2c and 2d when the stent graft 1 is bent. Thus, the low axial force and high flexibility of the stent graft 1 can be achieved.

[0073] Figure 3 and Figure 4 The relationship between the displacement of the bent portions 2c and 2d caused by the bending of the stent graft 1 and the deformation of the slack grafts 3 and 4 will be described. Figure 3 and Figure 4 In the figure, the left figure is a front view of the stent body 2 on the inner side of the bend, the central figure is a schematic diagram of the coatings 3 and 4 on the inner and outer sides of the bend, and the right figure is a schematic diagram of the wire members 2a on the inner and outer sides of the bend. Figure 3 and Figure 4 In the embodiment, both the inner coating 3 and the outer coating 4 have slack.

[0074] In the stent graft 1 from Figure 3 The straight shape is bent into Figure 4 When the stent graft 1 is bent, the apexes of the two curved portions 2c and 2d of the hooking portion 2b are displaced in the longitudinal direction and radially inward in the opposite directions on the inner and outer sides of the bend. At this time, the slack coatings 3 and 4 are deformed according to the displacement of the curved portions 2c and 2d in the longitudinal direction and radially inward. Therefore, when the stent graft 1 is bent, the two curved portions 2c and 2d can be displaced in the same manner as when there are no coatings 3 and 4, and low axial force can be achieved.

[0075] Next, a method for manufacturing the stent graft according to the present embodiment will be described.

[0076] like Figure 5As shown, the manufacturing method of the coated stent includes the following steps: step SA1, configuring the inner coating 3 on the first jig 20; step SA2, forming a loose portion 6 on the inner coating 3; step SA3, configuring the inner coating 3 on the inner side of the stent body 2; step SA4, configuring the outer coating 4 on the outer side of the stent body 2; step SA5, joining the inner coating 3 and the outer coating 4 to each other; and step SA6, removing the coated stent 1 from the autonomous jig 20.

[0077] like Figure 6 As shown, the jig 20 is a cylindrical mandrel, and a plurality of recesses 20a are formed on the outer surface of the mandrel 20 and arranged at intervals in the length direction. The plurality of recesses 20a are structures for forming the slack portion 6. Each recess 20a extends over the entire circumference and is recessed radially inward. A convex portion 20b is formed between adjacent recesses 20a.

[0078] like Figure 7 As shown, the inner film 3 is arranged on the outer surface of the mandrel 20 (step SA1). The form of the inner film 3 is selected from a tube, a belt and a sheet. In the case of a belt or a sheet, the inner film 3 is pre-formed into a tube and joined, and then arranged on the mandrel 20 or wound on the mandrel 20 without a gap.

[0079] Next, the inner film 3 is pressed into the recess 20a using a press-in tool 30 to form the slack portion 6 (step SA2). The press-in tool 30 is, for example, a rod-shaped or ring-shaped member. The inner film 3 is deformed along the inner surface of the recess 20a, thereby forming the slack portion 6 having a size and shape corresponding to the size and shape of the recess 20a. In order to reliably deform the inner film 3 along the inner surface of the recess 20a, the front end of the press-in tool 30 may have an outer surface shape complementary to the inner surface shape of the recess 20a.

[0080] Next, the mandrel 20 is inserted into the stent body 2, so that the stent body 2 is arranged on the outer surface of the inner coating 3 (step SA3). The stent body 2 and the inner coating 3 are aligned with each other at a position where the hooking portion 2b is arranged at the slack portion 6.

[0081] Next, the outer coating 4 is arranged on the stent body 2, and the stent body 2 is covered by the outer coating 4 (step SA4). As with the inner coating 3, the outer coating 4 is selected from a tube, a belt, and a sheet. In the case of a tube, the mandrel 20 provided with the inner coating 3 and the stent body 2 is inserted into the outer coating 4. In the case of a belt or sheet, the mandrel 20 is inserted into the outer coating 4 pre-formed into a tube, or the outer coating 4 is wound around the mandrel 20 over the entire circumference.

[0082] Next, the inner film 3 and the outer film 4 are bonded to a portion of the inner area of ​​the mesh of the stent body 2 by a bonding tool 40 by a method such as heat compression bonding, thereby forming a bonded portion 5 (step SA5). The bonded area is the inner area of ​​the mesh on the convex portion 20b, and the bonded portion 5 is formed between the two hooking portions 2b arranged at two adjacent slack portions 6 (see Figure 2A . ).

[0083] Next, core rod 20 is pulled out from inner coating 3 to produce stent graft 1 having slack portion 6 (step SA6 ).

[0084] Thus, according to the manufacturing method of this embodiment, it is possible to manufacture a stent graft 1 having low axial force and high flexibility in which inner coating 3 has slack due to slack portion 6 and coatings 3 and 4 do not hinder bending of stent body 2 .

[0085] In addition, the movable area of ​​the bending portion 2c, 2d depends on the size of the slack portion 6. In step SA2, the inner coating 3 is made to enter the recess 20a of the core rod 20, thereby forming a slack portion 6 of the same size as the recess 20a. As a result, the depth and width of the slack portion 6 can be easily and accurately controlled to form a slack portion 6 of a desired size, and the desired bending characteristics of the stent graft 1 can be reliably achieved. In addition, by making the size and shape of the recess 20a different at each position, a slack portion 6 of a different size and shape at each position can be easily formed.

[0086] Excessive relaxation of the inner coating 3 will lead to an increase in the diameter of the coated stent 1 in the contracted state, thereby increasing the sliding resistance of the coated stent 1 relative to the delivery system when the coated stent 1 is released from the delivery system, requiring a larger operating force. In addition, excessive relaxation of the inner coating 3 will reduce the volume of the hollow portion on the inner side of the coated stent 1 for the passage of substances in the body cavity. Therefore, it is important to control the slack portion 6 to a desired size. According to the present embodiment, by using a core rod 20 having a recess 20a as described above, the size of the slack portion 6 can be easily and accurately controlled.

[0087] Furthermore, of the two layers of coatings 3 and 4, only the inner coating 3 has slack portion 6, and the outer coating 4 has no slack portion. Therefore, it is possible to reduce the sliding resistance when the stent graft 1 is released from the delivery system.

[0088] In the present embodiment, the slack portion 6 is formed in a U-shaped groove shape having a flat bottom wall, but the shape of the slack portion 6 is not limited thereto and can be changed as appropriate.

[0089] Fig. 8A and Fig. 9A Another example of the longitudinal cross-sectional shape of the slack portion 6 is shown. Fig. 8AThe slack portion 6 is substantially M-shaped and has two side walls parallel to the radial direction and a curved bottom wall protruding radially outward. Fig. 9A The slack portion 6 is a substantially V-shaped portion having two side walls that form an angle with each other, one side wall being parallel to the radial direction and the other side wall being inclined relative to the radial direction. Such a slack portion 6 is formed by allowing the inner film 3 to enter the substantially M-shaped or substantially V-shaped recessed portion 20a. Alternatively, the front end portion of the press-fitting tool 30 may have a shape corresponding to the shape of the recessed portion 20a.

[0090] Figure 8B and Fig. 9B The slack portion 6 is shown folded under the effect of radial compressive force.

[0091] In the case of a substantially M-shaped slack portion 6, the two side walls are tilted outward, and the inner coating 3 partially overlaps the slack portion 6 in the radial direction outside the opening of the slack portion 6. In the case of a substantially V-shaped slack portion 6, the two side walls are tilted outward and in the same direction, and the inner coating 3 partially overlaps the slack portion 6 in the radial direction outside the opening of the slack portion 6.

[0092] Thus, substantially M-shaped or V-shaped slack portion 6 is deformed into a predetermined folded shape by radial compression force. Therefore, when stent graft 1 is mounted on a delivery system, slack portion 6 can be folded into a predetermined shape simply by compressing stent graft 1 in the radial direction.

[0093] The folding of the slack portion 6 causes the thickness of the inner coating 3 to be increased at the portion where the inner coating 3 partially overlaps in the radial direction (see Figure 8B and Fig. 9B Such a thicker portion is preferably arranged at a position offset from the hooking portion 2b formed by the radial overlap of the two portions 2c and 2d of the wire member 2a. FIG. 8A to FIG. 9B The slack portion 6 can control the folding shape of the slack portion 6 so that the thicker portion is arranged in an area that does not interfere with the hooking portion 2b.

[0094] (Second embodiment)

[0095] Next, a method for manufacturing a stent graft and a stent graft according to a second embodiment of the present invention will be described.

[0096] In this embodiment, the configurations different from those of the first embodiment will be described, and the configurations common to the first embodiment are denoted by the same reference numerals and description thereof will be omitted.

[0097] The stent graft of this embodiment includes a stent body 2, an inner coating 3 and an outer coating 4. The stent graft of this embodiment has slack portions 6 and 7 in the inner coating 3 and the outer coating 4, respectively (see Fig.11. ) This point is different from the coated stent 1 of the first embodiment.

[0098] The outer film 4 has a plurality of slack portions 7, which are arranged at intervals in the longitudinal direction of the outer film 4 and are formed at the same position as the slack portion 6. Each slack portion 7 is formed of a recess extending over the entire circumference of the outer film 4 and bulging radially inward, similarly to the slack portion 6, and is, for example, a U-shaped groove having a rectangular cross-sectional shape in a longitudinal section in the longitudinal direction. A portion of the hooking portion 2b is disposed between the slack portion 6 and the slack portion 7.

[0099] The outer coating 4 and the inner coating 3, which are relaxed by the relaxation portion 7, can be deformed freely according to the external force, allowing the longitudinal and radial movement of the pair of curved portions 2c and 2d forming the hooking portion 2b. Therefore, it is possible to prevent the coatings 3 and 4 from hindering the three-dimensional displacement of the curved portions 2c and 2d when the stent graft 1 is bent. Thus, the low axial force and high flexibility of the stent graft can be achieved.

[0100] like Fig.10 As shown, the manufacturing method of the coated stent of the present embodiment includes the following steps: step SB1, configuring the inner coating 3 on the jig 20; step SB2, configuring the inner coating 3 on the inner side of the stent body 2; step SB3, configuring the outer coating 4 on the outer side of the stent body 2; steps SB41 and SB42, forming loose portions 6 and 7 on the inner coating 3 and the outer coating 4; step SB5, joining the inner coating 3 and the outer coating 4 to each other; and step SB6, removing the coated stent from the autonomous jig 20.

[0101] The step of forming the slack portions 6 and 7 includes a step SB41 of forming the slack portion 6 in the inner coating film 3 before the step SB3 and a step SB42 of forming the slack portion 7 in the outer coating film 4 after the step SB3 .

[0102] like Fig.11 As shown, similarly to step SA1, the inner coating 3 is arranged on the outer surface of the mandrel rod 20 (step SB1).

[0103] Next, similarly to step SA2 , inner coating 3 is pressed into recess 20 a using press jig 30 to form slack portion 6 (step SB41 ).

[0104] Next, similarly to step SA3 , the core rod 20 is inserted into the stent body 2 , so that the stent body 2 is arranged on the outer surface of the inner coating 3 (step SB2 ).

[0105] Next, similarly to step SA4 , the outer coating 4 is disposed on the stent body 2 , and the stent body 2 is covered with the outer coating 4 (step SB3 ).

[0106] Next, the outer coating film 4 is pressed into the recessed portion 20 a using the press-fitting tool 30 to form the slack portion 7 (step SB42 ).

[0107] Next, the inner film 3 and the outer film 4 are bonded to a portion of the inner side of the mesh of the stent body 2 by a bonding tool 40 and a method such as thermal compression bonding, thereby forming a bonded portion 5 (step SB5). Fig. 12A As shown in FIG. 1 , the joining area is the area between two adjacent hooking parts 2b arranged in the same slack part 6, 7, and the joining part 5 is formed in the slack part 6, 7. The joining area may also be the same as the joining part 5 of the first embodiment. Fig. 12B As shown, a large-area joint portion 5 is formed in the wide slack portions 6 and 7.

[0108] Next, mandrel 20 is pulled out from inner coating 3 to produce a stent graft having slack portions 6 and 7 (step SB6).

[0109] As described above, according to the manufacturing method of this embodiment, a stent graft with low axial force and high flexibility can be manufactured in which both grafts 3 and 4 have slack due to slack portions 6 and 7 and grafts 3 and 4 do not hinder bending of stent body 2 .

[0110] Furthermore, the coatings 3 and 4 are inserted into the recess 20a of the mandrel 20 to form slack portions 6 and 7 of the same size as the recess 20a. Thus, the size of the slack portions 6 and 7 can be easily and accurately controlled to form slack portions 6 and 7 of desired size.

[0111] In this embodiment, the slack portions 6 and 7 may have the same structure as in the first embodiment. Fig. 8A and Fig. 9A The shape shown is deformable into a predetermined folded shape.

[0112] In the present embodiment, the slack portion 6 and the slack portion 7 are formed in different steps SB41 and SB42 , but instead, the slack portions 6 and 7 may be formed simultaneously in one step SB4 .

[0113] Fig.13 and Fig.14 A first modification of the manufacturing method of the second embodiment is described. In this modification, step SB4 of forming slack portions 6 and 7 is performed by simultaneously pressing inner coating 3 and outer coating 4 into recess 20a using pressing tool 30 after step SB3. According to this modification, the number of steps can be reduced.

[0114] The formation of the slack portions 6 and 7 and the bonding of the coatings 3 and 4 may be performed simultaneously in one step SB45 .

[0115] Fig.15 and Fig.16 A second variation of the manufacturing method of the second embodiment is described. In this variation, step SB45 is performed by simultaneously pressing the coatings 3 and 4 into the recess 20a using a bonding tool 40 such as a pressurizing or heating pin after step SB3 and bonding the coatings 3 and 4 to each other using the bonding tool 40. According to this variation, the number of steps can be further reduced.

[0116] In the present embodiment, the slack portion 6 is formed and then the coatings 3 and 4 are joined. However, instead, the coatings 3 and 4 may be joined (step SB5) and then the slack portions 6 and 7 may be formed (step SB4).

[0117] Fig.17 and Fig.18 A third modification of the manufacturing method of the second embodiment will be described. In this modification, the joint portion 5 (see Figure 2A . ) In the area inside the mesh on the convex portion 20b, the inner film 3 and the outer film 4 are joined to each other to form a joint portion 5 (step SB5). Thereafter, the films 3 and 4 are pressed into the concave portion 20a, and the films 3 and 4 are stretched to form slack portions 6 and 7 (step SB4).

[0118] (Third embodiment)

[0119] Next, a method for manufacturing a stent graft and a stent graft according to a third embodiment of the present invention will be described.

[0120] In this embodiment, the configurations different from those of the first embodiment will be described, and the configurations common to the first embodiment are denoted by the same reference numerals and description thereof will be omitted.

[0121] The stent graft of this embodiment includes a stent body 2, an inner coating 3, and an outer coating 4. The stent graft of this embodiment is configured such that the stent body 2 is disposed in a slack portion 6 of the inner coating 3 (see Fig.21 . ) This point is different from the coated stent 1 of the first embodiment.

[0122] The inner coating 3 has a plurality of slack portions 6 extending in the longitudinal direction and arranged in the circumferential direction in addition to the plurality of slack portions 6 extending in the longitudinal direction and arranged in the circumferential direction. These slack portions 6 are continuous with each other, and a grid-like recess is formed in the inner coating 3 as a whole. The wire member 2a of the stent body 2 is arranged in the slack portion 6.

[0123] like Fig.19As shown, the manufacturing method of the coated stent of the present embodiment includes the following steps: step SC1, configuring the inner coating 3 on the first jig 21; step SC2, configuring the stent body 2 on the outside of the inner coating 3 to form a loose portion 6; step SC3, configuring the outer coating 4 on the outside of the stent body 2; step SC4, joining the inner coating 3 and the outer coating 4 to each other; and step SC5, removing the coated stent from the autonomous jig 21.

[0124] like Fig. 20 As shown, the jig 21 has a plurality of convex portions 21b arranged at intervals in the longitudinal direction and the circumferential direction. The convex portion 21b is a columnar protrusion protruding radially outward from the outer circumferential surface of the jig 21. Concave portions 21a extending in the circumferential direction and concave portions 21a extending in the longitudinal direction are formed between the convex portions 21b, and these concave portions 21a are continuous with each other.

[0125] like Fig.21 As shown, the inner coating 3 is arranged on the convex portion 21b of the core rod 20 (step SC1).

[0126] Next, stent body 2 is placed on the outer surface of inner coating 3 so that convex portion 21b is located inside the mesh. Inner coating 3 is thereby recessed radially inward in the region of concave portion 21a, forming slack portion 6 in concave portion 21a (step SC2).

[0127] Next, the outer coating 4 is arranged outside the inner coating 3 , and the stent body 2 is covered with the outer coating 4 (step SC3 ).

[0128] Next, the inner coating 3 and the outer coating 4 are bonded together in the region of the protrusion 21 b to form the bonded portion 5 (step SC4 ).

[0129] Next, mandrel 21 is pulled out from inner coating 3 to produce a stent graft having slack portion 6 (step SC5 ).

[0130] Thus, according to the manufacturing method of this embodiment, since the slack portion 6 is formed by placing the stent body 2 on the inner coating 3, there is no need for a special press-in tool 30. In addition, since the inner coating 3 is uniformly pressed radially inward as a whole by the stent body 2, even without using the press-in tool 30, the size of the slack portion 6 can be easily and accurately controlled to form a slack portion 6 of a desired size.

[0131] Furthermore, since only inner coating 3 has slack portion 6 and outer coating 4 has no slack portion, it is possible to reduce the sliding resistance when the stent graft is released from the delivery system.

[0132] In the present embodiment, the plurality of recessed portions 21 a in the circumferential direction and the longitudinal direction are continuous with each other, but instead, they may be independent of each other like the recessed portions 20 a in the first embodiment.

[0133] (Fourth embodiment)

[0134] Next, a method for manufacturing a stent graft and a stent graft according to a fourth embodiment of the present invention will be described.

[0135] In this embodiment, the configurations different from those of the first embodiment will be described, and the configurations common to the first embodiment are denoted by the same reference numerals and description thereof will be omitted.

[0136] The stent graft of this embodiment includes a stent body 2, an inner coating 3, and an outer coating 4. The stent graft of this embodiment differs from the stent graft 1 of the first embodiment in that the inner coating 3 has no slack portion 6 and the outer coating 4 has a slack portion 7 that bulges radially outward.

[0137] The outer coating 4 has a plurality of slack portions 7 arranged at intervals in the length direction. Each slack portion 7 is composed of a recess extending over the entire circumference of the outer coating 4 and bulging radially outward. A portion of the hooking portion 2b is disposed between the inner coating 3 and the slack portion 7. The slack portion 7 forms a space between the inner coating 3 and the outer coating 4, and further provides slack to the outer coating 4. Therefore, similar to the inner coating 3 of the first embodiment, the outer coating 4 allows a pair of curved portions 2c, 2d forming the hooking portion 2b to move in the length direction and radial direction, and can prevent the coatings 3, 4 from obstructing the three-dimensional displacement of the curved portions 2c, 2d when the stent graft 1 is bent. Thus, low axial force and high flexibility of the stent graft can be achieved.

[0138] like Fig. 22 As shown, the manufacturing method of the coated stent of the present embodiment includes the following steps: step SD1, configuring the inner coating 3 on the first jig 22; step SD2, configuring the inner coating 3 on the inner side of the stent body 2; step SD3, configuring the outer coating 4 on the second jig 23; step SD4, forming a slack portion 7 on the outer coating 4; step SD5, configuring the outer coating 4 on the outer side of the inner coating 3; step SD6, joining the inner coating 3 and the outer coating 4 to each other; and step SD7, removing the coated stent from the autonomous jigs 22 and 23.

[0139] FIG. 23A to FIG. 23C The jigs 22 and 23 used in this embodiment are shown.

[0140] The first jig 22 is a cylindrical mandrel, and the outer surface of the mandrel 22 is a cylindrical surface without irregularities.

[0141] The second jig 23 is a cylindrical member, and a plurality of recesses 23b are formed on the cylindrical inner surface (mounting surface) 23a of the second jig 23 and are arranged at intervals in the longitudinal direction. The plurality of recesses 23b are used to form the slack portion 7. Each recess 23b extends over the entire circumference and is recessed radially outward. Fig. 23B and Fig.23C As shown, the second fixture 23 is composed of two semi-cylindrical halves 231 and 232 so that the inner surface 23a can be exposed. The two halves 231 and 232 can be separated from each other (see Fig. 23B . ), or it can be connected in a way that it can be opened and closed (refer to Fig.23C . ).

[0142] like Fig.24 As shown, similarly to step SA1, the inner coating 3 is arranged on the outer surface of the mandrel rod 22 (step SD1).

[0143] Next, similarly to step SA3 , stent body 2 is placed on the outer surface of inner coating 3 (step SD2 ).

[0144] Next, the outer coating 4 is disposed on the inner surface 23a of the second jig 23 (step SD3).

[0145] Next, the outer coating film 4 is pressed into the recessed portion 23 b using a press jig 30 (not shown) to form the slack portion 7 (step SD4 ).

[0146] Next, the outer coating 4 is arranged on the outside of the stent body 2 by inserting the core rod 22 into the second jig 23 (step SD5). Here, the outer coating 4 is arranged at a position in the center of the mesh of the stent body 2 by a joining mechanism (not shown) provided in the second jig 23 so as to be aligned with the stent body 2. The joining mechanism is a mechanism for joining the coatings 3 and 4. For example, the joining mechanism is a pin that protrudes from the inner surface 23a of the second jig 23 and pressurizes or heats the coatings 3 and 4, or a through hole for inserting an independent joining tool from the outside to the inside of the second jig 23.

[0147] Next, the coatings 3 and 4 are joined in a partial region inside the mesh by a joining mechanism, thereby forming a joined portion 5 (step SD6 ).

[0148] Next, mandrel 22 is pulled out from inner coating 3 to produce a stent graft having slack portion 7 (step SD7 ).

[0149] As described above, according to the manufacturing method of this embodiment, a stent graft with low axial force and high flexibility can be manufactured in which the outer coating 4 has slack due to the slack portion 7 and the coatings 3 and 4 do not hinder the bending of the stent body 2 .

[0150] Furthermore, the outer coating 4 is inserted into the recess 23b of the second jig 23 to form a slack portion 7 having the same size as the recess 23b. Thus, the size of the slack portion 7 can be easily and accurately controlled to form a slack portion 7 of a desired size.

[0151] In addition, of the two layers of coatings 3 and 4, only the outer coating 4 has slack 7, and the inner coating 3 has no slack. Therefore, the inner surface of the stent graft is smooth without irregularities, and substances in the body can flow smoothly in the hollow portion inside the stent graft.

[0152] In the present embodiment, the inner coating 3 does not have a slack portion, but instead, the inner coating 3 may have the slack portion 6 described in the first to third embodiments.

[0153] In this case, instead of the first jig 22, a first jig having a recessed portion, such as the core rods 20 and 21 of the first to third embodiments, is used in combination with the second jig 23. Thus, a stent graft can be manufactured in which the inner coating 3 has a slack portion 6 that bulges radially inward and the outer coating 4 has a slack portion 7 that bulges radially outward. Furthermore, the sizes and shapes of the slack portions 6 and 7 can be made different from each other.

[0154] (Fifth embodiment)

[0155] Next, a method for manufacturing a stent graft and a stent graft according to a fifth embodiment of the present invention will be described.

[0156] This embodiment is a modification of the fourth embodiment and differs from the fourth embodiment in the method of manufacturing a stent graft. In this embodiment, structures different from the first and fourth embodiments are described, and structures common to the first and fourth embodiments are denoted by the same reference numerals and description is omitted.

[0157] The stent graft of the present embodiment includes a stent body 2 , an inner coating 3 , and an outer coating 4 . The outer coating 4 has a slack portion 7 that bulges radially outward.

[0158] The method for manufacturing a stent graft according to the present embodiment includes steps SD1, SD2, SD3, SD4, SD5, SD6, and SD7 described in the fourth embodiment.

[0159] Fig.25A: shows the second jig 24 used in this embodiment. The second jig 24 is a flat member having a rectangular flat mounting surface 24a, and a plurality of recesses 24b are formed on the mounting surface 24a and arranged at intervals in the longitudinal direction. The recesses 24b are structures for forming the slack portion 7. Each recess 24b is composed of a groove extending over the entire width of the mounting surface 24a. The second jig 24 can be formed of a relatively hard material or a soft material such as silicon.

[0160] In the present embodiment, the outer coating film 4 is disposed on the mounting surface 24 a of the second jig 24 (step SD3 ).

[0161] Next, the outer coating film 4 is pressed into the recessed portion 24 b using the press-fitting tool 30 to form the slack portion 7 (step SD4 ).

[0162] Then, if Fig.26A As shown, the outer coating 4 is placed on the stent body 2 by rotating the placement surface 24a around the mandrel 22 and winding the outer coating 4 around the mandrel 21 (step SD5). After placing the outer coating 4, the second jig 24 is removed. Fig.26A and Fig.26B The stent body 2 and the inner coating 3 are omitted in the figure.

[0163] When the second jig 24 is flexible, Fig.26B As shown, the outer coating 4 is arranged on the stent body 2 by winding the second jig 24 around the mandrel 22. In this case, the inner coating 3 and the outer coating 4 may be joined using the joining mechanism described in the fourth embodiment while the second jig 24 is wound around the mandrel 22 (step SD6), and then the second jig 24 may be removed.

[0164] Thus, according to the manufacturing method of this embodiment, the second jig 24 is a simple shape formed by processing the concave portion 24b on the flat mounting surface 24a. Therefore, the concave portion 24b of various shapes and sizes can be formed with high precision, and the stent graft having the slack portion 7 of various shapes and sizes can be manufactured.

[0165] Fig.25B Another example of the second jig 24 is shown. In this way, the oblique recessed portion 24b can be easily formed. Fig.26B The second jig 24 is used in combination with the stent body 2 which is formed by winding the wire member 2a into a spiral shape and braiding it and in which the hooking parts 2b are arranged in a spiral shape.

[0166] In this embodiment, similarly to the fourth embodiment, a first jig having a recessed portion and a second jig 24 may be used in combination to manufacture a stent graft in which the inner coating 3 has a slack portion 6 and the outer coating 4 has a slack portion 7 .

[0167] In this embodiment, similarly to the first embodiment, the slack portions 6 and 7 may have Fig. 8A and Fig. 9A The shape shown is deformable into a predetermined folded shape. Fig.27A and Fig.27B Another example of the shape of the slack portions 6 and 7 that are deformed into a predetermined folded shape by radial compression is shown. In this way, the shape of the slack portions 6 and 7 can be changed in various ways.

[0168] In the first, second, fourth and fifth embodiments described above, the press jig 30 is used as a means for inserting the coatings 3 and 4 into the recesses 20a, 23b and 24b, but other means may be used instead.

[0169] For example, suction ports may be provided on the inner surfaces of the recesses 20a, 23b, 24b to suck the coatings 3 and 4 into the recesses 20a, 23b, 24b by suction. By such means, the coatings 3 and 4 can enter the recesses 20a, 23b, 24b and deform along the inner surfaces of the recesses 20a, 23b, 24b.

[0170] (Sixth Implementation Method)

[0171] Next, a method for manufacturing a stent graft and a stent graft according to a sixth embodiment of the present invention will be described.

[0172] In this embodiment, the configurations different from those of the first embodiment will be described, and the configurations common to the first embodiment are denoted by the same reference numerals and description thereof will be omitted.

[0173] like Fig.28A As shown, stent graft 10 of the present embodiment includes stent body 2 , tubular outer coating 41 covering the outside of stent body 2 , and fixation coating 8 disposed inside both ends of stent body 2 .

[0174] The stent body 2 can be deformed from an expanded state to a contracted state by contracting in the radial direction, and can be carried on the delivery system in the contracted state. Fig.28B As shown, the stent body 2 is extended in the length direction by contraction in the radial direction, and the length L2 of the stent body 2 in the contracted state is increased by, for example, about 20% to 50% compared to the length L1 of the stent body 2 in the expanded state.

[0175] The fixing film 8 is formed of ePTFE and is disposed over the entire circumference inside both ends of the stent body 2. Both ends of the outer film 41 are bonded to the fixing film 8, whereby the outer film 41 is connected to the stent body 2 at both ends.

[0176] The outer coating 41 is formed of ePTFE and has a stretching direction A showing high ductility. That is, the outer coating 41 is easy to extend along the stretching direction A, and is not easy to extend in a direction orthogonal to the stretching direction. Such stretching characteristics of the outer coating 41 are caused by the manufacturing method of ePTFE. The manufacturing method of ePTFE includes a process of stretching PTFE and a process of sintering the stretched PTFE. By stretching PTFE, nodes distributed in an island shape and fibrils extending along the stretching direction between the nodes are formed. In the stretching direction A where the fibrils are oriented, the ePTFE has high ductility.

[0177] The outer coating 41 is arranged in a direction in which the stretching direction A is consistent with the length direction of the stent body 2. In addition, in the expanded state, the outer coating 41 has slack in the length direction. That is, the full length of the outer coating 41 is the length obtained by adding the excess length to the length L1 of the stent body 2 in the expanded state. Such an outer coating 41 can be deformed freely according to external forces in the expanded state, allowing the pair of curved portions 2c and 2d that form the hooking portion 2b to move in the length direction and radial direction. Therefore, it is possible to prevent the outer coating 41 from obstructing the three-dimensional displacement of the curved portions 2c and 2d when the coated stent 10 is bent, and the low axial force and high flexibility of the coated stent 10 can be achieved.

[0178] Furthermore, since the stretching direction A of the outer coating 41 is consistent with the stretching direction of the stent body 2 during contraction, it is possible to prevent the outer coating 41 from rupturing or peeling off from the stent body 2 due to the stretching of the stent body 2. In the case where the ductility of the outer coating in the stretching direction of the stent body is low, the contraction of the coated stent may cause damage such as rupture of the outer coating or peeling off from the stent body.

[0179] Next, a method for manufacturing the stent graft according to the present embodiment will be described.

[0180] like Fig.29 As shown, the manufacturing method of the coated stent includes the following steps: step SE1, preparing an outer coating 41 and a fixing coating 8; step SE2, configuring the fixing coating 8 on the fixture 22; step SE3, configuring the fixing coating 8 on the inner side of the stent body 2; step SE4, configuring the outer coating 41 on the outer side of the stent body 2; step SE5, partially connecting the outer coating 41 to the stent body 2; and step SE6, causing the stent body 2 to shrink radially so as to stretch the outer coating 41.

[0181] like Fig.30As shown, considering the stretching direction A of the ePTFE, a rectangular outer film 41 and a strip-shaped fixing film 8 are cut from the ePTFE sheet (step SE1). The outer film 41 has a length direction and a width direction corresponding to the length direction and the circumferential direction of the stent body 2, respectively. The sheet is cut from the outer film 41 in such a way that the length direction of the outer film 41 is consistent with the stretching direction A of the ePTFE.

[0182] Then, if Fig.31 As shown, the fixing film 8 is wound around two locations of the jig 22 (step SE2). The jig 22 is a mandrel having a cylindrical outer surface without irregularities.

[0183] Next, by inserting the core rod 22 into the stent body 2 , the fixing coating 8 is arranged inside the both end portions of the stent body 2 (step SE3 ).

[0184] Next, the outer coating 41 is wound around the mandrel 22 over the entire circumference so that the longitudinal direction of the outer coating 41 coincides with the longitudinal direction of the stent body 2 , thereby placing the outer coating 41 outside the stent body 2 (step SE4 ).

[0185] Next, both ends of the outer coating 41 are bonded to the fixing coating 8 by any bonding method such as thermocompression bonding or adhesive, thereby connecting the outer coating 41 to the stent body 2 (step SE5). In step SE5, the ends of the outer coating 41 in the width direction are also bonded to the other parts of the outer coating 41 over the entire length, thereby forming the outer coating 41 into a tubular shape. After bonding, the assembly of the stent body 2, the outer coating 41, and the fixing coating 8 is removed from the mandrel 22 by pulling the mandrel 22 out of the stent body 2.

[0186] Next, the stent body 2 is contracted in the radial direction, so that the outer coating 41 is stretched in the length direction together with the stent body 2 (step SE6). Step SE6 can also be performed by inserting the assembly into a tube 50 having an inner diameter smaller than the diameter of the assembly in the expanded state. As a result, the length of the outer coating 41 increases, and slack is formed in the outer coating 41 relative to the length of the stent body 2 in the expanded state.

[0187] Thus, according to the manufacturing method of this embodiment, only the stent body 2 partially connected to the outer coating 41 is contracted radially, and relaxation is formed in the outer coating 41 to allow three-dimensional displacement of the bending portions 2c and 2d during bending. Thus, the stent graft 10 with low axial force and high flexibility can be easily manufactured.

[0188] Furthermore, since the stretching direction A of the outer coating 41 coincides with the stretching direction of the stent body 2 during contraction, it is possible to easily manufacture the stent graft 10 which is not easily breakable and has high reliability.

[0189] In this embodiment, the outer coating 41 is connected to the stent body 2 at both ends, but the number and position of the connection parts where the outer coating 41 is connected to the stent body 2 can be appropriately changed. For example, in order to improve the fixing force of the outer coating 41 to the stent body 2, the outer coating 41 can also be connected to the stent body 2 in the center in addition to the two ends.

[0190] In the connection parts joined by thermocompression bonding or the like, the structures of nodes and fibrils are destroyed, so the ductility of ePTFE is impaired. Therefore, the number of connection parts is preferably small.

[0191] In the present embodiment, the outer coating 41 is stretched by inserting the assembly into the tube 50 , but instead, the outer coating 41 may be stretched by mounting the assembly on a transport system.

[0192] The delivery system has a tubular sheath inserted into the body cavity, and stent graft 10 is mounted on the distal end of the sheath. After step SE5, the assembly is inserted into the sheath, so that stent body 2 can be contracted and outer coating 41 can be stretched while being mounted on the delivery system.

[0193] In the present embodiment, the manufacturing method includes step SE6 of stretching outer coating 41 , but step SE6 may not be included. In this case, stent graft 10 is provided in a state where outer coating 41 is not stretched.

[0194] Unstretched outer coating 41 is stretched by, for example, a user placing stent graft 10 itself on a delivery system, thereby stretching stent graft 10. Thus, slack can be formed in outer coating 41, and low axial force of stent graft 10 can be achieved.

[0195] (Seventh Implementation Method)

[0196] Next, a method for manufacturing a stent graft and a stent graft according to a seventh embodiment of the present invention will be described.

[0197] In this embodiment, the configurations different from those of the first embodiment and the sixth embodiment will be described, and the configurations common to the first embodiment and the sixth embodiment are denoted by the same reference numerals and description thereof will be omitted.

[0198] like Fig.32 As shown, the stent graft 11 of the present embodiment is different from the stent graft 10 of the sixth embodiment in that it includes a tubular inner coating 31 covering the inside of the stent body 2 in addition to the stent body 2 and the outer coating 41 .

[0199] The coatings 31 and 41 are partially joined to each other and are partially connected to the stent body 2. For example, the coatings 31 and 41 are joined to each other at a joint 5 which is a partial region inside the mesh of the stent body 2 and are separated from each other at other portions.

[0200] The inner coating 31 is formed of ePTFE similarly to the outer coating 41, has a stretching direction A showing high ductility, and is arranged in a direction that is consistent with the length direction of the stent body 2. In addition, in the expanded state, the inner coating 31 has slack in the length direction. That is, the total length of the inner coating 31 is the length obtained by adding the excess length to the length L1 of the stent body 2 in the expanded state.

[0201] The inner coating 31, like the outer coating 41, allows the pair of curved portions 2c, 2d forming the hooking portion 2b to move in the length direction and radial direction. Therefore, the coatings 31, 41 can be prevented from hindering the three-dimensional displacement of the curved portions 2c, 2d when the stent graft 11 is bent, and the stent graft 11 can achieve low axial force and high flexibility.

[0202] Furthermore, since the stretching direction A of coatings 31 and 41 coincides with the stretching direction of stent graft 11 during contraction, it is possible to prevent coatings 31 and 41 from being damaged or peeled off from stent body 2 due to the stretching of stent body 2 .

[0203] Next, a method for manufacturing the stent graft according to the present embodiment will be described.

[0204] like Fig.33 As shown, the manufacturing method of the coated stent includes the following steps: step SF1, preparing the inner coating 31 and the outer coating 41; step SF2, configuring the inner coating 31 on the fixture 22; step SF3, configuring the inner coating 3 on the inner side of the stent body 2; step SF4, configuring the outer coating 41 on the outer side of the stent body 2; step SF5, partially connecting the inner coating 31 and the outer coating 41 to the stent body 2; and step SF6, causing the stent body 2 to shrink radially, thereby stretching the inner coating 31 and the outer coating 41.

[0205] As in step SE1 , taking into account the stretching direction A of ePTFE, rectangular outer film 41 and rectangular inner film 31 are cut from the ePTFE sheet so that the longitudinal directions of films 31 , 41 coincide with the stretching direction A (step SF1 ).

[0206] Then, if Fig.34As shown in FIG. 2 , the inner film 31 is wound around the mandrel 22 over the entire circumference so that the length direction of the inner film 31 is aligned with the length direction of the mandrel 22, thereby arranging the inner film 31 on the outer surface of the mandrel 22 (step SF2). In step SF2, the end portions of the inner film 31 in the width direction are joined to the other portions of the inner film 31 over the entire length, so that the inner film 31 is formed into a tubular shape.

[0207] Next, the core rod 22 is inserted into the stent body 2 , so that the stent body 2 is arranged outside the inner coating 31 (step SF3 ).

[0208] Next, the outer coating 41 is wound around the mandrel 22 over the entire circumference so that the length direction of the outer coating 41 is aligned with the length direction of the stent body 2, thereby arranging the outer coating 41 outside the stent body 2 (step SF4). In step SF4, the end portions of the outer coating 41 in the width direction are joined to the other portions of the outer coating 41 over the entire length, so that the outer coating 41 is formed into a tubular shape.

[0209] Next, the outer film 41 and the inner film 31 are bonded to each other in a partial area inside the mesh by any bonding method such as thermocompression bonding or adhesive to form a joint portion 5, thereby connecting the films 31 and 41 to the stent body 2 (step SF5). After bonding, the mandrel 22 is pulled out from the inner film 31 to remove the assembly of the stent body 2 and the films 31 and 41 from the mandrel 22.

[0210] Next, similarly to step SE6, the stent body 2 is contracted in the radial direction, thereby stretching the coatings 31 and 41 along with the stent body 2 in the longitudinal direction (step SF6). Thus, the length of each coating 31 and 41 increases, and each coating 31 and 41 is loosened relative to the length of the stent body 2 in the expanded state.

[0211] Thus, according to the manufacturing method of this embodiment, only the stent body 2 partially connected to the two-layer coating 31, 41 is contracted radially, and relaxation is simultaneously formed in the coating 31, 41 to allow three-dimensional displacement of the bending parts 2c, 2d during bending. Thus, it is possible to easily manufacture a coated stent 11 with low axial force and high flexibility. Furthermore, since the stretching direction A of the coating 31, 41 is consistent with the stretching direction of the stent body 2 during contraction, it is possible to easily manufacture a coated stent 11 in which the coating 31, 41 is not easily damaged and has high reliability.

[0212] In step SF6 of the present embodiment, similarly to the sixth embodiment, the coatings 31 and 41 may be stretched by mounting the assembly on a transport system instead of mounting it on the tube 50 .

[0213] In the present embodiment, similarly to the sixth embodiment, the manufacturing method may not include step SF6 , and stent graft 11 may be provided in a state where grafts 31 , 41 are not stretched.

[0214] In the sixth and seventh embodiments, the stretching direction A of the coating 31, 41 is consistent with the length direction of the stent body 2, but in the case of the stent body 2 in which the wire member 2a is wound into a spiral shape, the stretching direction A may be consistent with the direction in which the wire member 2a extends when the stent body 2 contracts.

[0215] like Fig.35 As shown in FIG. 1 , the stent body 2 formed by winding the wire member 2a into a spiral shape and braiding it rotates and stretches in the direction in which the kink is loosened when the diameter is reduced in the radial direction. Therefore, by making the stretching direction A coincide with the stretching direction of the wire member 2a, the coating 31, 41 can be effectively stretched. In this case, in steps SE1 and SF1, the coating 31, 41 is cut out from the ePTFE sheet in such a manner that the length direction of the coating 31, 41 is inclined relative to the stretching direction A by an angle corresponding to the angle of the stretching direction of the wire member 2a.

[0216] In the sixth and seventh embodiments, the stent body 2 is not limited to the structure having the hooking portion 2b, but may be a stent body of other structures that are stretched in the length direction by radial contraction. In addition, the examples in which the coatings 31 and 41 are arranged over the entire length of the stent body 2 are disclosed, but the same effect can be achieved when the coatings are arranged partially on the stent body 2.

[0217] Furthermore, in the first to fifth embodiments, also in the arrangement of the ePTFE coating and the stent body, the stretching direction of the coating 31 , 41 can be made consistent with the stretching direction of the stent body 2 .

[0218] Above, the embodiments and modifications of the present invention are described in detail with reference to the accompanying drawings, but the specific structure is not limited to the above embodiments, and also includes design changes within the scope of the gist of the present invention. In addition, the constituent elements shown in the above embodiments and modifications can also be appropriately combined and constituted.

[0219] Description of Reference Numerals

[0220] 1, 10, 11, coated stent; 2, stent body; 2a, wire member; 2b, hooking portion; 2c, 2d, bending portion; 3, 31, inner coating; 4, 41, outer coating; 5, joining portion; 6, 7, relaxation portion; 20, 21, 22, first fixture (core rod); 23, 24, second fixture; 23a, 24a, loading surface; 20a, 21a, 23b, 24b, recessed portion.

Claims

1. A method for manufacturing a stent graft, wherein: The manufacturing method comprises the following operations: The inner coating is arranged inside a stent body having a mesh structure formed by weaving wire members, wherein the stent body has a hooking portion formed by two bent portions of the wire members hooking each other; Disposing an outer coating on the outside of the stent body; A slack portion bulging in the radial direction of the stent body is formed in at least one of the inner coating and the outer coating, and the slack portion provides slack to at least one of the inner coating and the outer coating to allow the two bending portions to move in the longitudinal direction of the stent body and in the radial direction; as well as The inner film and the outer film are joined to each other in a region inside the meshes of the grid structure.

2. The method for manufacturing a stent graft according to claim 1, wherein: The manufacturing method further includes the step of disposing the inner coating on the outer surface of a first columnar jig. The operation of forming the slack portion includes an operation of causing the inner coating film to enter a recess formed on the outer surface of the first jig before disposing the outer coating film, thereby forming the slack portion on the inner coating film.

3. The method for manufacturing a stent graft according to claim 2, wherein: The operation of forming the slack portion includes an operation of forming the slack portion in the outer coating film by causing the outer coating film to enter the recessed portion of the first jig after the outer coating film is disposed.

4. The method for manufacturing a stent graft according to claim 1, wherein: The manufacturing method further includes the step of disposing the inner coating on the outer surface of a first columnar jig. The operation of forming the slack portion includes an operation of forming the slack portion in the inner film and the outer film by simultaneously inserting the inner film and the outer film into a recess formed on the outer surface of the first jig after the outer film is disposed.

5. The method for manufacturing a stent graft according to claim 4, wherein: The operation of forming the slack portion and the operation of joining are simultaneously performed by pressing the inner coating and the outer coating into the recessed portion using a joining tool and joining the inner coating and the outer coating to each other using the joining tool.

6. The method for manufacturing a stent graft according to claim 1, wherein: The manufacturing method further includes the step of disposing the inner coating on the outer surface of a first columnar jig. The operation of arranging the stent body is an operation of arranging the stent body on the outer surface of the inner coating so that the protrusions provided on the outer surface of the first jig are located in the area inside the mesh of the grid structure, thereby forming the slack portion in the inner coating.

7. The method for manufacturing a stent graft according to claim 1, wherein: The manufacturing method further includes an operation of disposing the outer coating on a mounting surface of a second jig. The operation of forming the slack portion includes an operation of forming the slack portion in the outer coating by causing the outer coating to enter a recess formed on the mounting surface of the second jig before the outer coating is disposed on the outside of the stent body.

8. The method for manufacturing a stent graft according to claim 7, wherein: The second jig includes either a cylindrical member whose inner surface is the placement surface or a flat member having a flat placement surface.

9. The method for manufacturing a stent graft according to claim 1, wherein: The slack portion extends along the circumferential direction of the stent body.

10. The method for manufacturing a stent graft according to claim 9, wherein: The inner coating film and the outer coating film are joined to each other in a region between two adjacent engaging portions disposed in the slack portion.

11. The method for manufacturing a stent graft according to claim 9, wherein: A plurality of slack portions are formed and arranged at intervals from each other in the longitudinal direction of the stent body. The inner coating film and the outer coating film are joined to each other in a region between two adjacent slack portions.

12. The method for manufacturing a stent graft according to claim 1, wherein: The slack portion has a shape that is deformed into a predetermined folded shape under the radial compressive force. In the predetermined folded shape, a portion of the coating film constituting the slack portion overlaps in the radial direction outside an opening of the slack portion.

13. The method for manufacturing a stent graft according to claim 1, wherein: The inner film is made of ePTFE and is disposed on the stent body in a direction in which the ePTFE is stretched in a direction that coincides with the direction in which the stent body is stretched when the stent body is contracted in the radial direction.

14. The method for manufacturing a stent graft according to claim 1, wherein: The outer coating is made of ePTFE and is disposed on the stent body in a direction in which the ePTFE is stretched in a direction that coincides with the direction in which the stent body is stretched when the stent body is contracted in the radial direction.

15. A stent graft, wherein: The stent graft comprises: A stent body having a mesh structure formed by weaving wire members, the stent body having a hooking portion formed by two bent portions of the wire members hooking each other; An inner coating covering the inner side of the stent body; and An outer coating covering the outer side of the stent body, At least one of the inner coating and the outer coating has a slack portion that bulges in the radial direction of the stent body, and the slack portion provides slack to at least one of the inner coating and the outer coating to allow the two bending portions to move in the longitudinal direction of the stent body and in the radial direction. The inner coating film and the outer coating film are bonded to each other in a region inside the meshes of the grid structure.

16. The stent graft according to claim 15, wherein: The inner film is made of ePTFE, and is disposed on the stent body in a direction where the stretching direction of the ePTFE coincides with the stretching direction of the stent body when the stent body contracts in the radial direction.

17. The stent graft according to claim 15, wherein: The outer coating is made of ePTFE, and is disposed on the stent body in a direction in which the ePTFE is stretched in a direction that coincides with the direction in which the stent body is stretched when the stent body is contracted in the radial direction.

18. A method for manufacturing a stent graft, wherein: The ePTFE coating is arranged on at least one of the inner side and the outer side of the stent body in a direction where the stretching direction of the ePTFE coincides with the stretching direction of the stent body when it is contracted in the radial direction. The covering is partially connected to the stent body, The stent body is contracted in the radial direction to stretch the graft, thereby generating slack in the graft.

19. The method for manufacturing a stent graft according to claim 18, wherein: In the step of mounting the stent body connected to the graft on a delivery system, an operation of contracting the stent body in a radial direction to stretch the graft is performed.

20. A stent graft, wherein: The stent graft comprises: a support body; and The ePTFE coating covers at least one of the inner side and the outer side of the stent body and is partially connected to the stent body. The coating is arranged in a direction where the stretching direction of the ePTFE is consistent with the stretching direction of the stent body when it contracts in the radial direction. The coating has slack in the longitudinal direction of the stent body when the stent body is expanded in the radial direction.

Images