Living body-indwelling object

Abstract

[Problem] To provide a living body-indwelling object capable of suppressing reductions in deliverability by having a porous structure deform so as to expand outward in the radial direction. [Solution] A living body-indwelling object 100 includes: a stent 10 which extends in the axial direction, includes a tip end 10A and a base end 10B, is formed so as to be expandable in the radial direction, and has a plurality of wavy rings 11, which form the outer periphery of a cylindrical shape, and a link part 12 which connects adjacent rings to each other; a porous structure 20 that is disposed so as to cover the stent and has a plurality of penetrating voids; and a fixing part 30 where at least a portion of the porous structure is fixed to the stent at a position excluding the tip end and the base end.

Description

Living body incarceration

[0001] The present invention relates to a living body indwelling device.

[0002] A stent is a medical device that is delivered to a lesion in a biological lumen by a stent delivery system and then placed to expand the lesion, such as a stenosis or occlusion, and secure the lumen in order to treat various diseases caused by narrowing or occlusion of a biological lumen such as a blood vessel. A stent has linear rings that form the outer periphery of a cylindrical shape with gaps formed therein, and multiple links that connect the rings with gaps.

[0003] For example, Patent Document 1 listed below discloses a stent device in which a porous structure is arranged on the surface of a support element to prevent peripheral embolism during stent placement. The stent device can prevent thrombus scattering due to expansion of the support element by the porous structure expanding in accordance with the expansion of the support element.

[0004] WO2006 / 126182

[0005] In the stent device disclosed in Patent Document 1, the porous structure is fixed to the support element only at both ends of the support element, and therefore, during clinical use, the parts of the porous structure that are not fixed to the support element (parts excluding the ends) deform and expand radially outward, increasing the outer diameter and potentially reducing the deliverability of the stent device.

[0006] The present invention has been made in view of the above-mentioned problems, and aims to provide a living body indwelling device that can prevent a porous structure from deforming so as to expand radially outward, thereby preventing a decrease in deliverability.

[0007] The above object of the present invention can be achieved by the following means.

[0008] (1) A living body indwelling device comprising: a stent extending in an axial direction, having a distal end and a proximal end, being formed so as to be radially expandable, and having a plurality of wavy rings forming a cylindrical outer periphery, and link portions connecting adjacent rings; a porous structure disposed to cover the stent and having a number of through-holes; and a fixing portion at which at least a portion of the porous structure is fixed to the stent at a position other than the distal end and the proximal end.

[0009] (2) The living body indwelling device according to (1), wherein the fixing portion is provided on at least a part of the link portion.

[0010] (3) The indwelling device according to (1) or (2), wherein the fixing portion is provided on either one of the first strut or the second strut adjacent to the link portion on one side in the axial direction, and the pair of struts is provided in the circumferential direction.

[0011] (4) The indwelling device according to any one of (1) to (3), wherein the fixing portion is configured by fixing the porous structure directly to the stent at an exposed portion of the stent to which no drug is applied.

[0012] (5) The indwelling device according to any one of (1) to (4), further comprising, at the distal end and the proximal end, both end fixing portions for fixing the porous structure to the stent.

[0013] (6) The indwelling device according to any one of (1) to (5), wherein the porous structure is fixed to the outer periphery of the stent.

[0014] (7) The living body indwelling device according to any one of (1) to (6), wherein the fixing part is fixed by a polymer.

[0015] (8) The living body indwelling device according to any one of (1) to (6), wherein the fixing part is fixed with paraffin.

[0016] (9) The living body indwelling device according to any one of (1) to (8), wherein the porous structure is a structure in which the voids are formed between the thread-like materials by knitting or weaving the thread-like materials.

[0017] (10) The indwelling device according to (9), wherein the porous structure is a mesh having a knitted structure that can expand in response to the expansion of the stent.

[0018] (11) The indwelling device according to any one of (1) to (10), wherein the stent and the porous structure are fixed to the fixing portion by welding a biodegradable polymer.

[0019] (12) The indwelling device according to any one of (1) to (11), wherein the porous structure is formed by knitting, and the fixing portion is formed by fixing a loop portion knitted along the circumferential direction of the porous structure to the stent.

[0020] According to the indwelling device configured as described above, at least a portion of the porous structure is fixed to the stent by the fixing portion at a position other than the distal end and the proximal end, and therefore it is possible to prevent the porous structure from deforming so as to expand radially outward, which would increase the outer diameter of the entire indwelling device 100. Therefore, it is possible to provide an indwelling device that can prevent the porous structure from deforming so as to expand radially outward, which would reduce the delivery performance.

[0021] 8 is a schematic plan view showing a stent delivery system including a living body implant according to an embodiment of the present invention. FIG. 9 is a schematic plan view showing a diameter-reduced state of the living body implant according to this embodiment. FIG. 10 is a schematic plan view showing a diameter-expanded state of the living body implant according to this embodiment. FIG. 11 is a partial enlarged view showing the living body implant according to this embodiment. FIG. 12 is a partial enlarged view showing part A of FIG. 4. FIG. 13 is a cross-sectional view taken along line 7A-7A of FIG. 6. FIG. 14 is a cross-sectional view taken along line 7B-7B of FIG. 6. FIG. 15 is a schematic plan view showing the vicinity of the distal end of the living body implant according to this embodiment. FIG. 16 is a partial enlarged view showing part A of FIG. 17. The two-dot chain line indicates the shape of the stent when contracted, and the solid line indicates the shape of the stent when expanded. FIG. 17 corresponds to FIG. 4 and shows a living body implant according to a modified example. FIG. 18 is a schematic view showing a stent according to a modified example. FIG. 19 is a schematic view showing a stent according to a modified example.

[0022] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. Note that the following description does not limit the technical scope or meaning of terms described in the claims. Also, the dimensional proportions in the drawings are exaggerated for the convenience of explanation and may differ from the actual proportions.

[0023] The configuration of the living body indwelling device 100 according to this embodiment will be described below with reference to FIGS. 1 to 10. FIG. 1 is a schematic plan view showing a stent delivery system 300 including a living body indwelling device 100 according to an embodiment of the present invention. FIG. 2 is a schematic plan view showing the living body indwelling device 100 according to this embodiment in a contracted state. FIG. 3 is a schematic plan view showing the living body indwelling device 100 according to this embodiment in an expanded state. FIG. 4 is a partially enlarged view showing the living body indwelling device 100 according to this embodiment. FIG. 5 is a partially enlarged view showing portion A in FIG. 4. FIG. 6 is a partially enlarged view showing portion A in FIG. 5. FIG. 7A is a cross-sectional view taken along line 7A-7A in FIG. 6. FIG. 7B is a cross-sectional view taken along line 7B-7B in FIG. 6. FIG. 8 is a schematic plan view showing the vicinity of the distal end of the living body indwelling device 100 according to this embodiment. FIG. 9 is a partially enlarged view showing portion A in FIG. 8. In FIG. 10, the two-dot chain line indicates the shape of the stent 10 when contracted, and the solid line indicates the shape of the stent 10 when expanded.

[0024] 2 is referred to as the "axial direction" of the living body indwelling device 100, and the up-down direction of Fig. 2 is referred to as the "radial direction" of the living body indwelling device 100. In addition, the side inserted into the living body is referred to as the "distal side," and the side opposite the distal side where the surgeon operates the medical device is referred to as the "proximal side."

[0025] As shown in FIG. 1, the stent delivery system 300 includes an indwelling device 100 and a balloon catheter 200 .

[0026] <Balloon Catheter 200> First, we will explain the configuration of the balloon catheter 200. The balloon catheter 200 is used to deliver the indwelling device 100 in a contracted state to the lesion, expand it, and place it in the lesion.

[0027] The balloon catheter 200 has a long catheter body 210 , a balloon 220 provided at the tip of the catheter body 210 , and a hub 230 fixed to the base end of the catheter body 210 .

[0028] The catheter main body 210 includes an outer tube and an inner tube disposed inside the outer tube.

[0029] An inflation lumen is formed inside the outer tube, through which inflation fluid flows for inflating the balloon 220. The distal end of the outer tube is fixed to the proximal end of the balloon 220. The proximal end of the outer tube is fixed to the hub 230.

[0030] A guidewire lumen into which a guidewire is inserted is formed inside the inner tube. The distal end of the inner tube penetrates the interior of the balloon 220 and opens distally of the balloon 220. The proximal end of the inner tube penetrates the sidewall of the outer tube proximal to the balloon 220 and is fixed to the outer tube.

[0031] The catheter body 210 is preferably made of a material having a certain degree of flexibility, and examples thereof include polyolefins such as polyethylene, polypropylene, polybutene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ionomer, or a mixture of two or more of these; thermoplastic resins such as polyvinyl chloride resin, polyamide, polyamide elastomer, polyester, polyester elastomer, polyurethane, and fluororesin; silicone rubber; and latex rubber.

[0032] The balloon 220 is a component for expanding a stent such as the indwelling device 100 described below and placing it at a target site. The distal end of the balloon 220 is fixed to the outer wall surface of the inner tube. The proximal end of the balloon 220 is fixed to the outer wall surface of the distal end of the outer tube. Therefore, the interior of the balloon 220 communicates with an expansion lumen formed in the outer tube. An expansion fluid can flow into the balloon 220 from a proximal opening 231 via the expansion lumen. The balloon 220 expands when the expansion fluid flows in, and contracts and returns to a folded state when the inflowing expansion fluid is discharged.

[0033] The balloon 220 is preferably made of a flexible material that expands and contracts with the inflow and outflow of an inflation fluid. Examples of such materials include polymeric materials such as polyolefin, cross-linked polyolefin, polyester, polyester elastomer, polyvinyl chloride, polyurethane, polyurethane elastomer, polyphenylene sulfide, polyamide, polyamide elastomer, and fluororesin, as well as silicone rubber and latex rubber. The balloon 220 is not limited to a single polymeric material; a film formed by appropriately laminating multiple polymeric materials may also be used. The inflation fluid may be either a gas or a liquid, such as helium gas, CO2 gas, or O2 gas, or a liquid such as saline or an X-ray contrast medium.

[0034] The hub 230 has a proximal opening 231 that communicates with the inflation lumen of the outer tube. The proximal opening 231 functions as a port for the inflow and outflow of inflation fluid.

[0035] The material of which the hub 230 is made is not particularly limited, but examples include thermoplastic resins such as polyethylene, polyurethane, polyester, polypropylene, polycarbonate, polyamide, polysulfone, polyarylate, and methacrylate-butylene-styrene copolymer.

[0036] <Living body implant 100> Next, the configuration of the living body implant 100 will be described with reference to Figures 2 to 9. The living body implant 100 according to this embodiment is used to treat strictures or obstructions that occur in blood vessels, bile ducts, tracheas, esophagus, urethra, or other living body lumens. The living body implant 100 is a so-called balloon expansion type, in that it is placed in a crimped state on a folded balloon 220, and after being delivered to the lesion, it is expanded and placed at the lesion.

[0037] As shown in Figures 2 to 9, the indwelling device 100 has a stent 10 extending in the axial direction, a porous structure 20 arranged so as to cover the outer periphery of the stent 10, a fixing part 30 at which the porous structure 20 is fixed to the stent 10, and both end fixing parts 40 at which the porous structure 20 is fixed to the stent 10 at the distal end 10A and the proximal end 10B of the stent 10.

[0038] The stent 10 extends in the axial direction (left-right direction in FIGS. 2 and 3 ) and has a distal end 10A and a proximal end 10B. As shown in FIGS. 2 and 3 , the stent 10 is formed so as to be capable of radial expansion (the state shown in FIG. 3 ) and contraction (the state shown in FIG. 2 ). As shown in FIGS. 3 to 6 , the stent 10 has linear rings 11 that form the outer periphery of a cylindrical shape with gaps formed therein, and link portions 12 that connect the rings 11 with the gaps.

[0039] As shown in Figure 4, the wavy ring 11 has a plurality of first strut sections 15 each consisting of a straight or curved line, a plurality of second strut sections 16 each consisting of a straight or curved line, and a curved section 17 formed between the first strut section 15 and the second strut section 16.

[0040] The rings 11 are arranged in a line in the axial direction, and adjacent rings 11 in the axial direction are integrated by links 12. Therefore, by increasing or decreasing the number of rings 11, it is possible to easily obtain a stent 10 of a desired length.

[0041] The drug coated on the outer surface of the stent 10 is carried by a polymer to form the drug coating layer 18. The polymer is preferably a biodegradable polymer. In this case, after the stent 10 is placed in the body, the drug is gradually released while the polymer is biodegraded, thereby reliably preventing restenosis at the stent placement site and suppressing inflammation caused by the polymer.

[0042] The biodegradable polymer is, for example, at least one polymer selected from the group consisting of polyester, aliphatic polyester, polyanhydride, polyorthoester, polycarbonate, polyphosphazene, polyphosphate ester, polyvinyl alcohol, polypeptide, polysaccharide, protein, and cellulose, a copolymer obtained by arbitrarily copolymerizing the monomers constituting the polymer, and a mixture of the polymers and / or the copolymers. Examples of the aliphatic polyester include polylactic acid (PLA), polyglycolic acid (PGA), and lactic acid-glycolic acid copolymer (PLGA).

[0043] Drug coating layer 18 is disposed on first strut portion 15 and second strut portion 16 of ring 11 as shown in Figure 4, and on the outer surface of ring 11 as shown in Figure 7B.

[0044] In other words, the curved portion 17 and link portion 12 of the ring 11 (areas where stress concentrates and / or distortion occurs due to expansion and deformation) are not coated with a drug and no drug coating layer 18 is formed, so that stress concentration and / or distortion is avoided in the drug coating layer 18 even when the stent 10 is expanded.

[0045] A primer coating layer (not shown) may be disposed between the drug coating layer 18 and the outer surface of the stent 10. The primer constituting the primer coating layer is selected taking into consideration its adhesiveness to the polymer contained in the drug coating layer 18 and its adhesiveness to the outer surface of the stent 10, and the presence of the primer coating layer improves the peel resistance of the drug coating layer 18.

[0046] The stent 10 is made of a metal material or a polymer material. When the stent 10 is made of a metal material, the metal material used is not particularly limited, and any metal material typically used for stents 10 can be used. Specific examples of the metal include stainless steels such as SUS304, SUS316, SUS316L, SUS420J2, and SUS630, tantalum, titanium, nickel-titanium alloys, tantalum-titanium alloys, nickel-aluminum alloys, Inconel, gold, platinum, iridium, tungsten, and cobalt-based alloys such as cobalt-chromium (Co—Cr) alloys.

[0047] Furthermore, when the stent 10 is made of a polymer material, the polymer material to be used is not particularly limited, and any polymer material typically used for stents can be used, including polyolefins such as polyethylene and polypropylene, aromatic polyesters such as polyethylene terephthalate, cellulose-based polymers such as cellulose acetate and cellulose nitrate, and fluorine-containing polymers such as polytetrafluoroethylene and tetrafluoroethylene-ethylene copolymers.

[0048] The porous structure 20 is disposed so as to cover the outer periphery of the stent 10 and is expandable in response to the expansion of the stent 10. By disposing the porous structure 20 on the outer periphery of the stent 10, the stent 10 biases the porous structure 20 against the blood vessel when the stent 10 is expanded within the blood vessel, thereby reducing detachment of the porous structure 20 due to the pressure of the blood flowing within the blood vessel. The porous structure 20 extends axially and has a mesh structure. The gaps in the mesh structure of the porous structure 20 are configured to be smaller than the gaps between adjacent rings 11. This configuration can prevent peripheral embolism during expansion of the stent 10 when the stent 10 is placed. The porous structure 20 also has a large number of through-holes. The size of the gaps is preferably smaller in area than the gaps between the rings 11 of the stent 10. This can prevent the scattering of plaque and thrombus during expansion of the stent 10. On the other hand, the size of the gaps is preferably larger in area than the individual blood cells contained in the blood. This allows blood cells to pass through the voids. Furthermore, the large number of penetrating voids gives the porous structure 20 an extensible property, so that when the stent 10 is expanded in the radial direction, the porous structure 20 also expands in the circumferential direction, making it easier to follow the expansion of the stent 10.

[0049] The porous structure 20 includes knitted fabrics, woven fabrics (braided fabrics), and molded products. When the porous structure 20 is knitted, the porous structure 20 is formed by stockinette stitching. Since stockinette stitching is a well-known knitting method, detailed description thereof will be omitted. By forming the porous structure 20 by stockinette stitching, it is possible to prevent the axial shortening of the porous structure 20 as the stent 10 is expanded. When the porous structure 20 is woven, the woven fabric is formed by a well-known weaving method. The porous structure 20 may also be formed by a molded product in which holes are drilled in a tubular body formed by injection molding or the like. The size, shape, and number of the knitted and woven stitches of the porous structure 20 are not particularly limited as long as they are capable of preventing peripheral embolism during expansion of the stent 10.

[0050] The material constituting the porous structure 20 is not particularly limited, but examples thereof include (1) a polymer selected from the group consisting of aliphatic polyesters, polyesters, polyanhydrides, polyorthoesters, polycarbonates, polyphosphazenes, polyphosphate esters, polyvinyl alcohols, polypeptides, polysaccharides, proteins, and cellulose; and (2) a copolymer composed of two or more types of monomers constituting the above (1). The aliphatic polyester is not particularly limited, and examples thereof include polylactic acids (PLA) such as poly-L-lactic acid (PLLA), poly-D-lactic acid (PDLA), and poly-DL-lactic acid (PDLLA), polyglycolic acid (PGA), polyhydroxybutyric acid, polyhydroxyvaleric acid, polyhydroxypentanoic acid, polyhydroxyhexanoic acid, polyhydroxyheptanoic acid, poly(ε-caprolactone) (PCL), polytrimethylene carbonate, poly2,2-dimethyltrimethylene carbonate, polydioxanone, polybutyrolactone, polyvalerolactone, polymalic acid, polyethylene adipate, polyethylene succinate, polybutylene adipate, and polybutylene succinate. The polycarbonate is not particularly limited, and examples thereof include tyrosine-derived polycarbonate (Tyrosine-polycarbonate). Furthermore, polymers other than the biodegradable polymers mentioned above can also be used.

[0051] The porous structure 20 may also be made of a metal material, in which case the same metal materials as those listed for the stent 10 described above can be used.

[0052] The thread diameter of the porous structure 20 is not particularly limited, but can be, for example, 20 μm.

[0053] Generally speaking, the fixing portion 30 fixes at least a portion of the porous structure 20 to the stent 10 at a position excluding the distal end 10A and proximal end 10B of the stent 10. In this specification, the distal end 10A of the stent 10 is defined as "the most distal end of the stent 10, in a region where the distalmost link portion 12 is not provided." Also, in this specification, the proximal end 10B of the stent 10 is defined as "the most proximal end of the stent 10, in a region where the proximalmost link portion 12 is not provided."

[0054] The fixing portion 30 is a portion where the porous structure 20 is fixed to the stent 10. In this embodiment, the fixing portion 30 is composed of a weldable fixing member 50. By welding the fixing member 50 to the fixing portion 30, the porous structure 20 is embedded in the fixing member 50, and the porous structure 20 is fixed to the stent 10.

[0055] The fixing member 50 may be made of the polymer materials listed above as materials for forming the porous structure 20. Alternatively, the fixing member 50 may be made of paraffin.

[0056] In this embodiment, the fixing portions 30 are provided at all locations of the link portion 12, as shown in FIGS.

[0057] In the indwelling device 100 according to this embodiment, as shown in Figures 6 and 7A, the fixing portion 30 is provided on the link portion 12. Here, as shown in Figure 10, the link portion 12 is a portion where the axial geometric change accompanying the expansion of the stent 10 is small. Therefore, tension does not occur in the porous structure 20 accompanying the expansion of the stent 10, and peeling or breakage of the porous structure 20 can be suitably suppressed.

[0058] As described above, the link portions 12 are not provided with the drug coating layer 18. Therefore, as shown in Fig. 7A , the fixing portion 30 is configured by directly fixing the porous structure 20 to the stent 10 at the exposed portions 19 of the stent 10 where no drug is applied. In other words, as shown in Fig. 7A , the fixing members 50 constituting the fixing portion 30 are directly fixed to the link portions 12 of the stent 10. With this configuration, the adhesive strength of the porous structure 20 to the stent 10 when the fixing members 50 are welded can be improved compared to a configuration in which the fixing members 50 constituting the fixing portion 30 are fixed to the stent 10 via the drug coating layer 18.

[0059] The fixing portion 30 is configured by directly fixing the porous structure 20 to the stent 10 at the exposed portion 19 of the stent 10 where no drug is applied. Therefore, even if the fixing portion 30 is formed by heating such as laser irradiation, the efficacy of the drug is not lost because there is no drug coating layer 18. Note that the configuration in which the fixing member 50 is fixed to the stent 10 via the drug coating layer 18 can be adopted when the fixing portion 30 is formed by a method that does not require heating, such as with an adhesive, or that is minimally affected by heating.

[0060] 6, in the fixing portion 30, loop portions 21 of the stitches knitted along the circumferential direction of the porous structure 20 (the vertical direction in FIG. 6) are fixed to the stent 10. The fixed portion includes at least the loop portions 21, and may also include intersections with adjacent meshes. With this configuration, since the loop portions 21 extending along the circumferential direction are fixed to the stent 10, a long distance of the porous structure 20 can be embedded in the fixing member 50, improving the fixing force.

[0061] 8 and 9, the two-end fixing portions 40 fix the porous structure 20 to the stent 10 at the distal end 10A and the proximal end 10B of the stent 10. In particular, the two-end fixing portions 40 are preferably provided at the curved portion 18A at the distal end 10A of the stent 10 and at the curved portion (not shown) at the proximal end 10B of the stent 10, as shown in FIGS.

[0062] The method of fixing the porous structure 20 to the stent 10 at the both end fixing portions 40 is the same as the method of fixing the porous structure 20 to the stent 10 at the fixing portions 30 described above, and therefore a description thereof will be omitted.

[0063] In the living body indwelling device 100 according to this embodiment, since both end fixing portions 40 are present, when the living body indwelling device 100 is delivered to the lesion, even if the curve leading to the lesion is strong, the porous structure 20 can be prevented from being turned up from the stent 10.

[0064] As described above, the living body implant 100 according to this embodiment comprises a stent 10 extending in the axial direction, having a distal end 10A and a proximal end 10B, and being radially expandable, the stent 10 having a plurality of wavy rings 11 forming a cylindrical outer periphery and link portions 12 connecting adjacent rings 11; a porous structure 20 disposed to cover the stent 10 and having a number of voids therethrough; and a fixing portion 30 by which at least a portion of the porous structure 20 is fixed to the stent 10 at a position excluding the distal end 10A and the proximal end 10B. With the living body implant 100 configured in this manner, at least a portion of the porous structure 20 is fixed to the stent 10 by the fixing portion 30 at a position excluding the distal end 10A and the proximal end 10B, which prevents the porous structure 20 from deforming so as to expand radially outward, thereby preventing the outer diameter of the living body implant 100 from increasing. This prevents the porous structure 20 from deforming so as to expand radially outward, thereby preventing a decrease in the deliverability of the living body implant 100.

[0065] The fixing part 30 is provided on the link part 12. According to the living body indwelling device 100 configured in this manner, peeling or damage to the porous structure 20 can be suitably suppressed.

[0066] The fixing part 30 is configured by directly fixing the porous structure 20 to the stent 10 at the exposed part 19 of the stent 10 where no drug is applied. With the indwelling device 100 configured in this manner, the adhesive strength when the fixing member 50 is welded can be improved compared to a configuration in which the fixing member 50 constituting the fixing part 30 is fixed to the stent 10 via the drug coating layer 18.

[0067] The indwelling device 100 further has, at the distal end 10A and the proximal end 10B, two-end fixing portions 40 for fixing the porous structure 20 to the stent 10. With the indwelling device 100 configured in this manner, when the indwelling device 100 is delivered to the lesion, the porous structure 20 can be prevented from being turned up from the stent 10 even if the path to the lesion is strongly curved.

[0068] Furthermore, the stent 10 and the porous structure 20 are fixed by welding a biodegradable polymer to the fixing part 30. According to the indwelling device 100 configured in this manner, the fixing part 30 is biodegradable, so that inflammation caused by the polymer is suppressed.

[0069] The porous structure 20 is constructed by stockinette knitting, and the fixing portion 30 is constructed by fixing loop portions 21 of a mesh knitted along the circumferential direction of the porous structure 20 to the stent 10. According to the indwelling device 100 constructed in this manner, since the loop portions 21 knitted along the circumferential direction are fixed to the stent 10, the porous structure 20 can be embedded over a long distance in the fixing member 50, improving the fixing force.

[0070] The configuration of the living body indwelling device 100 according to the present invention has been described above through the embodiments, but the present invention is not limited to the configurations described in the embodiments, and can be modified as appropriate based on the claims.

[0071] For example, in the above-described embodiment, the fixing portions 30 are provided at all locations of the link portions 12, but the fixing portions 30 may be provided at some locations of all of the link portions 12. With this configuration, it is possible to reduce the amount of fixing member 50 used that constitutes the fixing portions 30, while preventing the porous structure 20 from deforming so as to expand radially outward, thereby preventing the outer diameter from increasing.

[0072] In the above-described embodiment, the fixing portion 30 is provided on the link portion 12. However, the fixing portion may be provided on the first strut portion 15 or the second strut portion 16. This configuration also prevents the porous structure 20 from deforming in a radially outward direction, thereby preventing a decrease in the deliverability of the indwelling device.

[0073] In the above-described embodiment, the fixing portion 30 is provided on the link portion 12. However, the fixing portion may be provided on the link portion and the strut. In this configuration, the fixing portion is provided on the link portion and the strut, which further improves strength.

[0074] In the above-described embodiment, the fixing portion 30 is provided on the link portion 12. However, as shown in Fig. 11 , the fixing portion 430 of a modified in vivo indwelling device 400 may be provided on the third strut portion (first strut) 14 and / or the second strut portion (second strut) 16, which are adjacent to the link portion 12 on one side in the axial direction (e.g., the left side in Fig. 11 ) and are provided as a pair in the circumferential direction (up and down in Fig. 11 ). Note that Fig. 11 shows, as an example, a form in which the fixing portion 430 is provided on the third strut portion 14 and the second strut portion 16. With this configuration, the third strut portion 14 and the second strut portion 16 are provided near the link portion 12, and therefore the change in axial geometry before and after expansion is small compared to the other struts, thereby reducing peeling or damage to the porous structure 20. Furthermore, compared to a configuration in which a fixing portion is provided on the first strut portion 15 or the second strut portion 16, this configuration reduces the likelihood of a large gap occurring between a first strut portion 15 and the next first strut portion 15 spaced apart in the radial direction, thereby reducing peeling or damage to the porous structure 20. Furthermore, when a fixing portion 430 is provided on the third strut portion 14 or the second strut portion 16, peeling or damage to the porous structure 20 can be further reduced compared to when fixing portions 430 are provided on both the third strut portion 14 and the second strut portion 16.

[0075] In the above-described embodiment, the stent 10 and the porous structure 20 are fixed to each other at the fixing portion 30 by welding a biodegradable polymer. However, the method for fixing the porous structure 20 to the stent 10 is not limited, and may be welding a polymer other than a biodegradable polymer. Furthermore, the fixing may be by adhesive bonding, bundling with a cable tie, clip fixing, or the like.

[0076] In the above-described embodiment, the indwelling device 100 is a balloon-expandable stent, but it may be a so-called self-expandable stent that is compressed in the direction of its central axis when inserted into a living body and expands outward when placed in the living body, restoring it to its pre-compression shape. When the stent 10 is a self-expandable stent, it is preferable to use a superelastic alloy such as a nickel-titanium alloy, since it requires a force that restores it to its original shape.

[0077] The shape of the stent is not particularly limited, and may be a stent having a shape as shown in Figures 12 and 13. For example, a stent 510 shown in Figure 12 has a ring 511 and a link portion 512. A stent 610 shown in Figure 13 has a ring 611 and a link portion 612.

[0078] Furthermore, in the above-described embodiment, the fixing member 50 is melted by irradiating it with a laser, but the fixing member 50 may also be melted by irradiating it with a light beam or ultrasonic waves, or by heating the entire fixing member 50.

[0079] This application is based on Japanese Patent Application No. 2023-150811, filed on September 19, 2023, the disclosure of which is incorporated herein by reference in its entirety.

[0080] 10, 510, 610 Stent, 10A Distal end of stent, 10B Base end of stent, 11, 511, 611 Ring, 12, 512, 612 Link portion, 14 Third main strut portion, 15 First main strut portion, 16 Second main strut portion, 17 Curved portion, 19 Exposed portion, 20 Porous structure, 21 Loop portion, 30, 130, 430 Fixing portion, 40 Both end fixing portions, 100, 400 In-vivo indwelling device.

Claims

1. A biological indwelling device comprising: a stent extending in an axial direction, having a tip and a base end, being formed so as to be radially expandable, having a plurality of wavy rings forming a cylindrical outer circumference, and link portions connecting adjacent rings; a porous structure having a number of penetrating voids, arranged to cover the stent; and a fixing portion at which at least a portion of the porous structure is fixed to the stent at a position other than the tip and the base end.

2. The living body indwelling device according to claim 1, wherein the fixing portion is provided on at least a part of the link portion.

3. A biological indwelling device as described in claim 1 or 2, wherein the fixing portion is provided on one of the first struts or the second struts adjacent to the link portion on one side of the axial direction, and which are arranged in a pair in the circumferential direction.

4. The indwelling device according to claim 1 or 2, wherein the fixing portion is configured by directly fixing the porous structure to the stent at an exposed portion of the stent to which no drug is applied.

5. The indwelling device according to claim 1 or 2, further comprising, at said distal end and said proximal end, end fixing portions at both ends for fixing said porous structure to said stent.

6. The indwelling device according to claim 1 or 2, wherein the porous structure is fixed to the outer periphery of the stent.

7. The indwelling device according to claim 1 or 2, wherein the fixing part is fixed by a polymer.

8. The indwelling device according to claim 1 or 2, wherein the fixing portion is fixed with paraffin.

9. The indwelling device according to claim 1 or 2, wherein the porous structure is a structure in which the voids are formed between the threads by knitting or weaving the threads.

10. The indwelling device according to claim 9, wherein the porous structure is a knitted mesh that is expandable in response to the expansion of the stent.

11. The indwelling device according to claim 1 or 2, wherein the stent and the porous structure are fixed to the fixing portion by welding a biodegradable polymer.

12. A biological indwelling device as described in claim 1 or 2, wherein the porous structure is formed by knitting, and the fixing portion is formed by fixing a loop portion knitted along the circumferential direction of the porous structure to the stent.

Images