JP2017086094A - Stent - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a stent capable of suppressing occurrence of flaring, while demonstrating excellent expansion holding force, and obtaining high followability to deformation of a living body lumen.SOLUTION: A stent 10 includes: a stent base 20 constituted of linear components, formed in a tube shape having a clearance as a whole, and deformable so as to be expanded in the direction outside; and at least one linear reinforcement component 30 formed of a biodegradable material, and connected at least on one point to at least one of the linear components located at both ends of the stent base 20 in the axial direction thereof.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a stent for maintaining an open state of a living body lumen by being placed in a stenosis part, an obstruction part or the like generated in the living body lumen.

  In recent years, for example, in the treatment of myocardial infarction and angina pectoris, a method of securing a space in a coronary artery by placing a stent in a lesion (stenosis) of a coronary artery has been performed, and other blood vessels, bile ducts, trachea, A similar method may be used for treatment of stenosis in the esophagus, urethra, and other living body lumens. Stents are classified into balloon-expandable stents and self-expandable stents by function and placement method.

  The balloon-expandable stent has no expansion function in the stent itself, and is placed outside the balloon of a balloon catheter having an expandable balloon, inserted into a target site, expanded by the balloon, and plastically deformed so that a living body such as a blood vessel can be obtained. It is tightly fixed in the lumen.

  For example, as described in Patent Document 1, a stent is a tube having linear gaps in which linear components extending in a circumferential direction while being bent in a wave shape are aligned in the axial direction and adjacent components are connected to each other. It has a shape.

JP 2009-82245 A

  Since the linear components located at both ends in the axial direction of the stent described above have other adjacent components only on one side, the holding force (strength) in the radial direction is compared with the other components. And it is low. For this reason, since the vascular expansion holding force in the radial direction possessed by the stent is large at the central portion and low at both end portions in the axial direction of the stent, the ability to expand and hold the blood vessels at both end portions becomes insufficient. there is a possibility.

  In addition, as described above, the strength of both ends of the stent is lower than that of the central portion, so that when the stent is bent excessively, for example, when moving in the blood vessel, only the components at both ends are in diameter. A phenomenon (flaring) that deforms so as to spread outward in the direction is likely to occur. When flaring occurs, the expanded site of the stent is likely to be caught in the blood vessel, and it may be difficult to move the stent within the blood vessel.

  It should be noted that a stent having a closed cell structure in which all sides and vertices of cells (openings) constituting a mesh (mesh) are shared with adjacent cells has a large metal area, and therefore sufficient at both ends of the stent. Strength is ensured, and it is possible to suppress the decrease in the holding force in the radial direction and the occurrence of flaring. However, due to the large amount of metal, it is bulky and the conveyance performance is reduced, and the biological lumen after stent placement is deformed. There is a possibility that the followability with respect to will decrease.

  The present invention has been made in order to solve the above-described problems, and provides a stent that can suppress the occurrence of flaring while exhibiting a good expansion holding force and that can obtain high followability to deformation of a living body lumen. The purpose is to provide.

  The stent according to the present invention that achieves the above object is formed of a linear component and is formed in a cylindrical shape having a gap as a whole, and is deformable so as to expand radially outward, and a biodegradable material And at least one linear reinforcing member connected to at least one of the linear components located at both axial ends of the stent substrate.

  Since the reinforcing member is connected to at least one of the linear components located at both ends in the axial direction in the stent configured as described above, the strength at the axial end portion of the stent is improved. For this reason, when the stent expands in the radial direction in the living body lumen, it exhibits a good holding force in the radial direction with respect to the living body lumen, and when moving in the living body lumen in a state before expansion. Thus, it is possible to effectively suppress the occurrence of flaring that expands the end. Further, since the reinforcing member is formed of a biodegradable material, the above-described stent is placed in the living body lumen, and the reinforcing member is decomposed and disappears after a predetermined period of time, and becomes a flexible stent. High followability to lumen deformation can be obtained.

  In the stent, if the reinforcing member is formed in a range of less than 360 degrees in the circumferential direction of the stent, the reinforcing member is only partially used in the circumferential direction while effectively using the linear components. Therefore, it is possible to suppress the occurrence of flaring while exhibiting a good expansion holding force with the addition of a minimum configuration.

  If the reinforcing member is formed over 360 degrees in the circumferential direction of the stent, the stent can effectively improve the strength at the end of the stent, and thus exhibits a good expansion holding force. However, the occurrence of flaring can be effectively suppressed.

  In the stent, if a rough surface having a rougher surface than other parts is formed in a part connected to the reinforcing member of the linear component, the connection of the reinforcing member to the linear component is possible. It becomes strong and the drop-off of the reinforcing member from the linear component is suppressed, thereby improving safety.

  The stent is configured such that a portion of the linear component connected to the reinforcing member is covered with a material having higher affinity for the reinforcing member than the material constituting the linear component. As a result, the connection of the reinforcing member to the linear component is strengthened, and the dropout of the reinforcing member from the linear component is suppressed, thereby improving safety.

  If the stent has a portion that is bent so as to protrude in the axial direction of the stent in a state before the stent is expanded, the reinforcing member is expanded after the stent base is expanded. Since the bent portion of the member is deformed to be closer to a straight line without becoming thin, the strength of the end portion of the stent after expansion is increased, and a high expansion holding force can be obtained.

  If the stent has a portion formed linearly along the circumferential direction of the stent in a state before the stent is expanded, the end of the stent in the state before expansion is provided. The strength of the portion is increased, and the occurrence of flaring can be effectively suppressed.

It is a top view which shows the state before the stent which concerns on 1st Embodiment expands. It is an expanded view which shows the state before the stent which concerns on 1st Embodiment expands. It is an expansion development view showing a part before the stent concerning a 1st embodiment expands. It is sectional drawing which follows the AA line of FIG. It is sectional drawing which shows the modification of the stent which concerns on 1st Embodiment. It is sectional drawing which shows the other modification of the stent which concerns on 1st Embodiment. It is sectional drawing which shows the other modification of the stent which concerns on 1st Embodiment. It is sectional drawing which shows the other modification of the stent which concerns on 1st Embodiment. It is sectional drawing which shows the other modification of the stent which concerns on 1st Embodiment. It is a top view which shows the balloon catheter for indwelling a stent in a biological lumen. It is sectional drawing which shows the front-end | tip part of a balloon catheter. It is sectional drawing which shows the front-end | tip part of the balloon catheter at the time of expanding a balloon. It is an expanded view which shows the state after the stent which concerns on 1st Embodiment has expanded. It is an expanded view which shows the state before the stent which concerns on 2nd Embodiment expands. It is an expanded view which shows the state after the stent which concerns on 2nd Embodiment has expanded. It is an expanded view which shows the state before the stent which concerns on 3rd Embodiment expands. It is an expanded view which shows the state after the stent which concerns on 3rd Embodiment expands. It is an expanded view which shows the state before the modification of the stent which concerns on 3rd Embodiment expands. It is an expanded view which shows the state before the stent which concerns on 4th Embodiment expands. It is an expanded view which shows the state after the stent which concerns on 4th Embodiment expands. It is the schematic which shows the state which expanded the stenosis part with the stent which concerns on 4th Embodiment. It is an expanded view which shows the state before the stent which concerns on 5th Embodiment expands. It is an expanded view which shows the state after the stent which concerns on 5th Embodiment expands. It is an expanded view which shows the state before the stent which concerns on 6th Embodiment expands. It is an expanded view which shows the state after the stent which concerns on 6th Embodiment expands. It is an expanded view which shows the state before the stent which concerns on 7th Embodiment expands. It is an expanded view which shows the state after the stent which concerns on 7th Embodiment expands. It is an expanded view which shows the state before the stent which concerns on 8th Embodiment expands. It is an expanded view which shows the state after the stent which concerns on 8th Embodiment expands. It is an expanded view which shows the state before the stent which concerns on 9th Embodiment expands. It is an expanded view which shows the state after the stent which concerns on 9th Embodiment expands.

Embodiments of the present invention will be described below with reference to the drawings. In addition, the dimension ratio of drawing is exaggerated on account of description, and may differ from an actual ratio.
<First Embodiment>

  The stent 10 according to the first embodiment is used to treat a stenosis or occlusion occurring in a blood vessel, bile duct, trachea, esophagus, urethra, or other living body lumen.

  The stent 10 is a so-called balloon-expandable stent that expands by the expansion force of the balloon, and as shown in FIGS. 1 to 3, a cylindrical stent base body 20 that is composed of linear components and has a gap as a whole, Reinforcing members 30 connected to both ends in the axial direction X with respect to the stent base 20 are provided. The stent 10 according to the present embodiment has an open cell structure in which some of the sides or vertices of cells (openings) constituting a mesh (mesh) are not shared with adjacent cells.

  The stent base body 20 includes a plurality of spiral bodies 21 formed in a spiral shape around the axial direction X of the stent 10 by zigzag linear components folded back in a wave shape, and both ends of the spiral body 21. And two annular bodies 23 formed endlessly.

  Each spiral body 21 is formed by drawing a 360 ° spiral, and all the spiral bodies 21 are arranged in series to form one spiral. Each spiral body 21 is formed by being folded back in a plurality of wave shapes. The number of spiral bodies 21 is not particularly limited. Further, the number of the spiral bodies 21 that are folded back in a zigzag manner is not particularly limited. Since the stent base 20 includes the spiral body 21 formed in a spiral shape, the stent 10 is provided with flexibility, and the stent 10 easily deforms following the deformation of a biological lumen such as a blood vessel. , The influence on the living body can be reduced.

  The spiral bodies 21 adjacent to each other in the axial direction X of the stent base body 20 are integrally connected by the first link member 22. When the stent 10 is expanded, the first link member 22 is twisted so that the spiral of the spiral body 21 connected in series is stretched, and the bent portion of the spiral body 21 is not opened. It plays a role of suppressing deformation while reducing the number of turns of the spiral.

  The two annular bodies 23 are integrally connected to the adjacent spiral body 21 by the second link member 24. By providing the endlessly formed annular body 23 at both ends of the stent base body 20, the blood vessel expansion holding force at both ends of the stent 10 becomes high.

  Each annular body 23 is formed with a first folded portion 23A that is bent so as to protrude in the end direction along the axial direction X, and a second folded portion 23B that is bent in the opposite direction, and the first folded portion 23A. And the 2nd folding | turning part 23B is arrange | positioned alternately by the circumferential direction.

  The reinforcing member 30 is made of a biodegradable material, and is connected to the annular bodies 23 (linear components) at both ends in the axial direction X of the stent base body 20. A plurality of reinforcing members 30 are provided in each of the annular bodies 23, and each reinforcing member 30 is formed in a range of less than 360 degrees in the circumferential direction of the stent 10. Each reinforcing member 30 is a linear member including a curved portion 31 protruding toward the end portion of the stent 10 along the axial direction X of the stent 10 in a state before the stent 10 is expanded. A first end portion 32 and a second end portion 33 are formed in the direction opposite to the curved portion 31. Each reinforcing member 30 is disposed between two circumferentially adjacent first folded portions 23 </ b> A in the annular body 23, and the first end portion 32 of the reinforcing member 30 has two adjacent first folded portions. It is connected between one of 23A and the 2nd folding | turning part 23B located between the two 1st folding | turning parts 23A. The second end portion 33 of the reinforcing member 30 is connected between the other of the two adjacent first folded portions 23A and the second folded portion 23B located between the two first folded portions 23A. Has been. Therefore, the first folded portions 23A and the reinforcing members 30 of the annular body 23 are alternately arranged in the circumferential direction. In the present embodiment, the reinforcing member 30 is provided in all the spaces between the adjacent first folded portions 23A. However, the reinforcing member 30 may not necessarily be provided in all the spaces. What is necessary is just to provide above.

  Since the reinforcing member 30 is formed of a biodegradable material, it is decomposed and disappears after the stent 10 is placed in the living body lumen.

  And the 1st end part 32 and the 2nd end part 33 of the reinforcement member 30 are joined so that a part of outer surface 25 and the side surface 26 of the annular part 23 may be covered, as shown in FIG. The reinforcing member 30 is formed with a substantially constant thickness.

  In addition, the joining form with respect to the stent base | substrate 20 of the reinforcement member 30 is not limited to the form shown in FIG. For example, as shown in FIG. 5, the reinforcing member 30 may be formed so as to be thinner from the first end portion 32 and the second end portion 33. Further, as shown in FIG. 6, the reinforcing member 30 may be joined to the annular portion 23 so as to cover the outer surface 25, the side surface 26, and the inner surface 27 of the annular portion 23. In addition, as shown in FIG. 7, the reinforcing member 30 may be joined to the annular portion 23 so as to cover one side surface 26 of the annular portion 23, a part of the outer surface 25, and a part of the inner surface 27. Further, the reinforcing member 30 may be joined only to the side surface 26 of the annular portion 23 as shown in FIG.

  The stent base body 20 varies depending on the indwelling site, but generally has an outer diameter of 1.5 to 20 mm, preferably 2.0 to 10 mm, and a wall thickness of 0.02 to 1 when expanded (when the diameter is not reduced). The length is 0.0 mm, preferably 0.04 to 0.5 mm, and the length is 5 to 250 mm, preferably 8 to 200 mm. The helical pitch (interval between adjacent spiral bodies 21) is 0.1 to 3 mm, preferably 0.3 to 1.0 mm.

  The thickness of the reinforcing member 30 is not particularly limited, but is preferably −0.02 mm to +0.02 mm with respect to the thickness of the stent substrate 20.

  The stent substrate 20 is made of a non-biodegradable metal material such as a stainless steel, a cobalt base alloy such as a cobalt-chromium alloy, an elastic metal such as a platinum-chromium alloy, a superelastic alloy such as a nickel-titanium alloy, or the like. It is preferable that the metal material is integrally formed in a substantially cylindrical shape.

  The stent base 20 is produced by removing non-component parts such as the stent base 20 using a metal pipe, thereby forming an integrally formed product. The formation of the stent base 20 by the metal pipe can be performed by cutting (for example, mechanical polishing, laser cutting), electric discharge machining, chemical etching, or the like, and may be performed by using them together.

  As the biodegradable material used for the reinforcing member 30, a biodegradable metal or a biodegradable polymer is preferably used. In addition, the biodegradable material preferably has adhesiveness with the stent substrate 20.

  As the biodegradable metal, pure magnesium or a magnesium alloy, calcium, zinc, lithium or the like is used. Preferred is pure magnesium or a magnesium alloy. The magnesium alloy contains magnesium as a main component and contains at least one element selected from a biocompatible element group consisting of Zr, Y, Ti, Ta, Nd, Nb, Zn, Ca, Al, Li, and Mn. Those that do are preferred.

  As a magnesium alloy, for example, magnesium is 50 to 98%, lithium (Li) is 0 to 40%, iron is 0 to 5%, and other metals or rare earth elements (cerium, lanthanum, neodymium, praseodymium, etc.) are 0 to 0%. Mention may be made of 5%. Further, for example, magnesium is 79 to 97%, aluminum is 2 to 5%, lithium (Li) is 0 to 12%, and rare earth elements (cerium, lanthanum, neodymium, praseodymium, etc.) are 1 to 4%. be able to. Moreover, for example, magnesium is 85 to 91%, aluminum is 2%, lithium (Li) is 6 to 12%, and rare earth elements (cerium, lanthanum, neodymium, praseodymium, etc.) are 1%. Also, for example, magnesium is 86 to 97%, aluminum is 2 to 4%, lithium (Li) is 0 to 8%, and rare earth elements (cerium, lanthanum, neodymium, praseodymium, etc.) are 1 to 2%. be able to. Also, for example, aluminum is 8.5 to 9.5%, manganese (Mn) is 0.15 to 0.4%, zinc is 0.45 to 0.9%, and the remainder is magnesium. it can. Moreover, for example, aluminum is 4.5 to 5.3%, manganese (Mn) is 0.28 to 0.5%, and the remainder is magnesium. For example, magnesium is 55 to 65%, lithium (Li) is 30 to 40%, and other metals and / or rare earth elements (cerium, lanthanum, neodymium, praseodymium, etc.) are 0 to 5%. Can do.

  The biodegradable polymer is not particularly limited as long as it is enzymatically and non-enzymatically degraded in vivo and the degradation product does not exhibit toxicity. For example, polylactic acid, polyglycolic acid, polylactic acid- Polyglycolic acid copolymer, polycaprolactone, polylactic acid-polycaprolactone copolymer, polyorthoester, polyphosphazene, polyphosphoric acid ester, polyhydroxybutyric acid, polymalic acid, poly alpha-amino acid, collagen, gelatin, laminin, heparan sulfate Fibronectin, vitronectin, chondroitin sulfate, hyaluronic acid, polypeptide, chitin, chitosan and the like can be used.

  Moreover, in order to improve the adhesiveness with the forming material of the reinforcement member 30, you may surface-treat the whole or a part in the junction part of the stent base | substrate 20 joined with the reinforcement member 30. FIG. Examples of the surface treatment include a method of forming a rough surface whose surface is rougher than other surrounding portions. Moreover, as a surface treatment, as shown in FIG. 9, a method of covering the surface with a material having a high affinity for the forming material of the reinforcing member 30 as a primer (covering portion 28) is also preferable. Although various materials can be used as the primer material, the most preferable one is a silane coupling agent having a hydrolyzable group and an organic functional group. The silanol group generated by the decomposition of the hydrolyzable group (for example, alkoxy group) of the silane coupling agent is bonded to the surface of the joining portion (free end portion) of the metal easily deformable portion by a covalent bond or the like. The organic functional group (for example, epoxy group, amino group, mercapto group, vinyl group, methacryloxy group) can be bonded to the polymer in the resin adhesive layer by a chemical bond. Specific examples of the silane coupling agent include γ-aminopropylethoxysilane and γ-glycidoxypropylmethyldimethoxysilane. Examples of primer materials other than silane coupling agents include organic titanium coupling agents, aluminum coupling agents, chromium coupling agents, organic phosphoric acid coupling agents, organic vapor deposition films such as polyparaxylene, and cyanoacrylates. Adhesives, polyurethane-based paste resins, and the like.

  Further, a physiologically active substance may be included in the forming material of the reinforcing member 30. Physiologically active substances include agents that suppress intimal thickening, anticancer agents, immunosuppressive agents, antibiotics, anti-rheumatic agents, antithrombotic agents, HMG-CoA reductase inhibitors, ACE inhibitors, calcium antagonists, anti-high fats Antihypertensive agent, anti-inflammatory agent, integrin inhibitor, antiallergic agent, antioxidant, GPIIbIIIa antagonist, retinoid, flavonoid and carotenoid, lipid improver, DNA synthesis inhibitor, tyrosine kinase inhibitor, antiplatelet agent, vascular smoothing Muscle growth inhibitors, anti-inflammatory drugs, biological materials, interferons and epithelial cells generated by genetic engineering are used. And you may use 2 or more types of mixtures, such as said chemical | medical agent.

  As the anticancer agent, for example, vincristine, vinblastine, vindesine, irinotecan, pirarubicin, paclitaxel, docetaxel, methotrexate and the like are preferable. As the immunosuppressant, for example, sirolimus, tacrolimus, azathioprine, cyclosporine, cyclophosphamide, mycophenolate mofetil, gusperimus, mizoribine and the like are preferable. As the antibiotic, for example, mitomycin, adriamycin, doxorubicin, actinomycin, daunorubicin, idarubicin, pirarubicin, aclarubicin, epirubicin, pepromycin, dinostatin styramer and the like are preferable. As the anti-rheumatic agent, for example, methotrexate, sodium thiomalate, penicillamine, lobenzalit and the like are preferable. As the antithrombotic drug, for example, heparin, aspirin, antithrombin preparation, ticlopidine, hirudin and the like are preferable. As the HMG-CoA reductase inhibitor, for example, cerivastatin, cerivastatin sodium, atorvastatin, nisvastatin, itavastatin, fluvastatin, fluvastatin sodium, simvastatin, lovastatin, pravastatin and the like are preferable. As the ACE inhibitor, for example, quinapril, perindopril erbumine, trandolapril, cilazapril, temocapril, delapril, enalapril maleate, lisinopril, captopril and the like are preferable. As the calcium antagonist, for example, nifedipine, nilvadipine, diltiazem, benidipine, nisoldipine and the like are preferable. As the antihyperlipidemic agent, for example, probucol is preferable. As the antiallergic agent, for example, tranilast is preferable. As the retinoid, for example, as the all-trans retinoic acid flavonoid and carotenoid, for example, catechins, particularly epigallocatechin gallate, anthocyanin, proanthocyanidins, lycopene, β-carotene and the like are preferable. As the tyrosine kinase inhibitor, for example, genistein, tyrphostin, arbustatin and the like are preferable. As the anti-inflammatory agent, for example, steroids such as dexamethasone and prednisolone are preferable. Examples of the biological material include EGF (epidemal growth factor), VEGF (basic endowment growth factor), HGF (hepatocyte growth factor), PDGF (platelet growth factor), PDGF (platelet growth factor).

  Next, a method of placing the stent 10 according to the present embodiment in a living body lumen will be described by taking the case of placing it in a blood vessel as an example. When placing the stent 10, a balloon catheter 200 shown in FIGS. 10 and 11 is used.

  The balloon catheter 200 includes a long catheter body 220, a balloon 230 provided at the distal end of the catheter body 220, a hub 240 fixed to the proximal end of the catheter body 220, and an outer peripheral surface of the balloon 230. It has the stent 10 mounted in the diameter state.

The catheter main body 220 includes an outer tube 250 that is a tubular body having an open distal end and a proximal end, and an inner tube 260 disposed inside the outer tube 250. The outer tube 250 has an expansion lumen 251 through which an expansion fluid for expanding the balloon 230 flows, and the inner tube 260 has a guide wire lumen 261 through which the guide wire W is inserted. ing. The expansion fluid may be gas or liquid, and examples thereof include gas such as helium gas, CO ₂ gas, and O ₂ gas, and liquid such as physiological saline and contrast medium.

  The inner tube 260 has a distal end portion that penetrates the inside of the balloon 230 and opens at the distal end side of the balloon 230, and a proximal end portion that penetrates the side wall of the outer tube 250 and is attached to the outer tube 250 with an adhesive or It is fixed liquid-tightly by heat sealing.

  The hub 240 includes a proximal end opening 241 that functions as a port for communicating with the expansion lumen 251 of the outer tube 250 and allows the expansion fluid to flow in and out, and the proximal end of the outer tube 250 has an adhesive, heat fusion, and the like. It is fixed liquid-tightly by wearing or a fastener (not shown).

  The outer tube 250 and the inner tube 260 are preferably formed of a material having a certain degree of flexibility. Examples of such a material include polyethylene, polypropylene, polybutene, ethylene-propylene copolymer, and ethylene-acetic acid. Polyolefins such as vinyl copolymers, ionomers, or a mixture of two or more of these, thermoplastic resins such as soft polyvinyl chloride resins, polyamides, polyamide elastomers, polyesters, polyester elastomers, polyurethanes, fluororesins, silicone rubbers, latex rubbers Etc. can be used.

  As a constituent material of the hub 240, a thermoplastic resin such as polycarbonate, polyamide, polysulfone, polyarylate, methacrylate-butylene-styrene copolymer can be suitably used.

  The balloon 230 has a cylindrical portion 231 that is formed in a substantially cylindrical shape in the central portion in the axial direction X so as to efficiently expand a predetermined range by being expanded. On the distal end side of the cylindrical portion 231 of the balloon 230, a first diameter-reduced portion 232 having a diameter reduced in a tapered shape toward the distal end side is provided, and on the proximal end side, toward the proximal end side. A second reduced diameter portion 233 is provided which is formed with a diameter decreasing toward the taper. The stent 10 is placed on the outer peripheral surface of the cylindrical portion 231.

  The distal end side of the first reduced diameter portion 232 is liquid-tightly fixed to the outer wall surface of the inner tube 260 by an adhesive or heat fusion, and the proximal end side of the second reduced diameter portion 233 is the outer tube. It is liquid-tightly fixed to the outer wall surface of the front end portion of 250 by an adhesive or heat fusion. Therefore, the inside of the balloon 230 communicates with the expansion lumen 251 formed in the outer tube 250, and the expansion fluid can flow from the proximal end side through the expansion lumen 251. The balloon 230 is expanded by the inflow of the expansion fluid, and is folded by discharging the inflowing expansion fluid.

  When the balloon 230 is not expanded, the balloon 230 is shaped so as to be folded around the outer peripheral surface of the inner tube 260 in the circumferential direction. Such a balloon 230 can be formed by blow molding in which a tube serving as a material is heated in a mold and pressed from the inside so as to swell with a fluid and pressed against the mold.

  The balloon 230 is preferably formed of a material having a certain degree of flexibility. Examples of such a material include polyethylene, polypropylene, polybutene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, Polyolefins such as ionomers or mixtures of two or more thereof, soft polyvinyl chloride resins, polyamides, polyamide elastomers, polyesters, polyester elastomers, polyurethanes, fluororesins and other thermoplastic resins, silicone rubbers, latex rubbers and the like can be used.

  When the stent 10 is placed in a blood vessel by the balloon catheter 200, first, for example, before treating the stenosis of the blood vessel, air in the balloon 230 and the expansion lumen 251 is extracted as much as possible, and the balloon 230 and the expansion lumen are extracted. The inside of 251 is replaced with an expansion fluid. At this time, the balloon 230 is in a folded state. Further, the inside of the inner tube 260 is replaced with physiological saline.

  Next, the sheath is placed in the patient's blood vessel by, for example, the Seldinger method, and the guide wire W and the guiding catheter are inserted into the blood vessel from the inside of the sheath while the guiding wire W is inserted through the guiding catheter. Subsequently, the guiding catheter is advanced while the guide wire W is advanced, so that the guiding catheter reaches the vicinity of the stenosis. Thereafter, with the proximal end of the guide wire W inserted through the guide wire lumen 261 of the balloon catheter 200, the balloon catheter 200 is inserted into the guiding catheter along the guide wire W, and the balloon catheter 200 is advanced. The balloon 230 is made to reach the stenosis.

  Next, in a state where the balloon 230 is positioned at the constricted portion, a predetermined amount of an expansion fluid is injected from the proximal end opening 241 of the hub 240 using an indeflator, a syringe, a pump, or the like, and the balloon 230 is passed through the expansion lumen 251. An expansion fluid is fed into the inside of 230, and the folded balloon 230 is expanded. As a result, as shown in FIG. 12, the cylindrical portion 231 of the balloon 230 expands the stenosis and expands the stent 10 while plastically deforming it, and maintains the stenosis in a state of being expanded by the stent 10. As shown in FIG. 13, the stent 10 is deformed and expanded so that the bent portion of the linear component of the stent base 20 is opened, and the first end portion 32 and the second end portion of each reinforcing member 30 are expanded. The distance between 33 spreads and the curved part 31 is deformed into a shape closer to a straight line without becoming thin.

  Thereafter, the expansion fluid is sucked and discharged from the proximal opening 241, and the balloon 230 is contracted and folded. The stent 10 is indwelled in the stenosis portion while being in the expanded state. Thereafter, the guide wire W, the balloon catheter 200 and the guiding catheter are removed from the blood vessel through the sheath, and the sheath is further removed to complete the procedure. In the stent 10 placed in the blood vessel, the tissue in the blood vessel is stabilized over time and the whole is covered with endothelial cells, and the reinforcing member 30 is disassembled and disappears after a predetermined period of time. It will be left. In addition, since the stent 10 is covered with endothelial cells, a part of the reinforcing member 30 does not fall into the bloodstream while the reinforcing member 30 is being decomposed. In particular, as shown in FIG. 5, if the reinforcing member 30 is formed so as to be thinner away from the first end portion 32 and the second end portion 33, the portion of the reinforcing member 30 connected to the stent base body 20. Is finally disassembled, the separation of the reinforcing member 30 from the stent base 20 can be suppressed, and a part of the reinforcing member 30 can be more reliably suppressed from falling into the bloodstream.

  And since the reinforcement member 30 is provided in at least one side (both sides in this embodiment) of the both ends of the axial direction X in the stent 10 according to the present embodiment, the strength at the end in the axial direction X is increased, When expanded in the radial direction within the blood vessel (biological lumen), a good holding force in the radial direction with respect to the blood vessel can be exhibited, and the state in which the blood vessel is expanded can be maintained well. Further, since the strength at the end portion in the axial direction X of the stent 20 is increased by the reinforcing member 30, when the stent 20 is excessively bent when moving in the blood vessel in a state before expansion, the stent 20 Flaring that deforms so that the end portion expands radially outward can be suppressed satisfactorily, and the stent 20 becomes less likely to be caught in the blood vessel, thereby improving delivery performance and safety. In addition, unlike the stent having a closed cell structure, the stent 10 according to the present embodiment is flexible without being bulky, and thus can exhibit high transport performance and also exhibits good followability to the deformation of blood vessels after placement of the stent. Further, in the stent 10 according to the present embodiment, since the reinforcing member 30 includes a biodegradable material, the reinforcing member 30 is disassembled and disappears after a predetermined period of time after being placed in the blood vessel and becomes flexible as a stent. In addition to being able to obtain high followability to the deformation of blood vessels, it is possible to suppress a decrease in durability against pulsation. Further, since the reinforcing member 30 is formed in a linear shape, deformation is allowed by bending or extending according to the expansion of the stent 10.

  And the stent 10 which concerns on this embodiment arrange | positions the stent 10 in a blood vessel by the reinforcement member 30 being arrange | positioned at the front end side (insertion direction side with respect to a biological body) of the balloon 230 at least among the both ends of the stent 10. When moving, the distal end of the stent 10 is difficult to expand, the stent 10 is difficult to be caught in a narrowed portion such as a stenosis, and exhibits high pushing performance (conveyance performance) and safety. high. In addition, the stent 10 according to the present embodiment is configured such that the reinforcing member 30 is disposed at least on the proximal end side (the proximal side where the operation is performed) of the balloon 230 among the both ends of the stent 10, so that the stent 10 is placed in the blood vessel. When the stent 10 is moved, the proximal end side of the stent 10 is difficult to expand, and when the stent 10 that has passed through a portion having a narrow inner diameter such as a stenosis portion is pulled back, the stent 10 becomes difficult to be caught by the living body, which is high. Delivers high transport performance and high safety.

  Further, in the stent 10 according to the present embodiment, since the annular body 23 to which the reinforcing member 30 is connected is formed in an endless shape (ring shape), the blood vessel expansion holding force at the end portion of the stent 10 is higher. It can be.

  Further, in the stent 10 according to the present embodiment, the reinforcing member 30 is formed in a range of less than 360 degrees in the circumferential direction of the stent 10, and the first end portion 32 and the second end portion 33 are linear configurations of the stent base body 20. Since it is connected with the element, the reinforcing member 30 can be disposed only partially in the circumferential direction while effectively using the linear component. For this reason, the stent 10 can suppress generation | occurrence | production of flare ring, exhibiting a favorable expansion holding force only by addition of the minimum reinforcement member 30. FIG.

  In addition, the stent 10 according to the present embodiment is configured such that a rough surface having a higher roughness than other parts is formed in a part connected to the reinforcing member 30 of the linear component of the stent base 20. And the connection with respect to the linear component of the reinforcement member 30 becomes strong, and the drop-off | omission from the linear component of the reinforcement member 30 is suppressed, and safety | security improves.

  In addition, the stent 10 according to the present embodiment has higher affinity for the reinforcing member 30 than the material constituting the linear component at the portion connected to the reinforcing member 30 of the linear component of the stent base 20. By covering the material, the connection of the reinforcing member 30 to the linear component is strengthened, and the falling of the reinforcing member 30 from the linear component is suppressed, thereby improving safety.

Further, since the reinforcing member 30 is bent so as to protrude in the axial direction X of the stent 10 before the stent 10 is expanded, the reinforcing member 30 is bent after the stent 10 is expanded. The curved portion 31 is deformed into a state closer to a straight line without becoming thin. For this reason, the strength of the end portion of the stent 10 after the expansion is increased, and a high expansion holding force for the blood vessel can be obtained.
Second Embodiment

  As shown in FIG. 14, the stent 40 according to the second embodiment is different from the stent 10 according to the first embodiment only in the configuration of the reinforcing member 41. In addition, the same code | symbol is attached | subjected to the site | part which has the same function as 1st Embodiment, and description is abbreviate | omitted in order to avoid duplication.

  The reinforcing member 41 of the stent 40 according to the second embodiment is made of a biodegradable material, and is connected to the annular bodies 23 at both ends in the axial direction X of the stent base body 20. One reinforcing member 41 is provided in each of the annular bodies 23, and each reinforcing member 41 is formed in the circumferential direction of the stent 40 over 360 degrees. Each reinforcing member 41 is a linear member including a plurality of curved portions 42 protruding toward the end portion of the stent 40 along the axial direction X of the stent 40 in a state before the stent 40 is expanded. A connecting portion 43 connected to the first folded portion 23A of the annular body 23 is formed in the direction opposite to the bending portion 42 along the direction X. Therefore, the first folded portions 23A of the annular body 23 and the curved portions 42 of the reinforcing member 41 are alternately arranged in the circumferential direction. In addition, the number of the curved parts 42 and the connection parts 43 provided in each reinforcing member 41 may be smaller than the number of the first folded parts 23A of the annular body 23. In this case, the first connection part 43 is not connected. The folded portion 23A exists. Since the reinforcing member 41 is formed of a biodegradable material, it is decomposed and disappears after the stent 40 is placed in the living body lumen.

  Next, the operation of the stent 40 according to the second embodiment will be described.

  When the stent 40 is expanded at the stenosis portion by the balloon 230 (see FIG. 10), the stent 40 is expanded while the stenosis portion is expanded and plastically deformed, and the shape is maintained in a state where the stenosis portion is expanded. At this time, as shown in FIG. 15, the stent 40 is deformed and expanded so that the bent portion of the linear component of the stent base 20 is opened, and the adjacent connection portions 43 of the reinforcing members 41 are connected to each other. The distance therebetween increases, and the curved portion 42 is deformed into a shape closer to a straight line without becoming thin.

  As described above, in the stent 40 according to the second embodiment, since the reinforcing member 41 is formed over 360 degrees in the circumferential direction of the stent 40, the reinforcing member is less than 360 degrees before the stent 40 expands. Compared with the case where it forms with, the intensity | strength of the edge part of the stent 40 can be improved effectively. For this reason, the stent 40 can suppress generation | occurrence | production of a flare ring effectively, exhibiting high expansion holding force.

Further, the stent 40 according to the second embodiment is formed so that the reinforcing member 41 is bent so as to protrude in the axial direction X of the stent 40 before the stent 40 expands. After the expansion, the bent portion 42 of the reinforcing member 41 is deformed into a state closer to a straight line without becoming thin. For this reason, the strength of the end portion of the stent 40 after the expansion is increased, and a high expansion holding force for the blood vessel can be obtained.
<Third Embodiment>

  As shown in FIG. 16, the stent 50 according to the third embodiment is different from the stent 10 according to the first embodiment only in the configuration of the reinforcing member 51. In addition, the same code | symbol is attached | subjected to the site | part which has the same function as 1st Embodiment, and description is abbreviate | omitted in order to avoid duplication.

  The reinforcing member 51 of the stent 50 according to the third embodiment is made of a biodegradable material, and is connected to the annular bodies 23 at both ends in the axial direction X of the stent base body 20. One reinforcing member 51 is provided in each of the annular bodies 23, and each reinforcing member 51 is formed in a linear shape over 360 degrees in the circumferential direction of the stent 50. Each reinforcing member 51 has a connection portion 52 connected to the first folded portion 23A of the annular body 23 in a state before the stent 50 is expanded. In addition, the number of the connection parts 52 provided in each reinforcing member 51 may be smaller than the number of the first folding parts 23A of the annular body 23. In this case, the first folding parts 23A to which the connection parts 52 are not connected are provided. Will exist. Since the reinforcing member 51 is formed of a biodegradable material, it is decomposed and disappears after the stent 50 is placed in the living body lumen.

  Next, the operation of the stent 50 according to the third embodiment will be described.

  When the stent 50 is expanded at the stenosis portion by the balloon 230 (see FIG. 10), the stent 50 is expanded while being expanded and plastically deformed, and the shape is maintained in a state where the stenosis portion is expanded. At this time, as shown in FIG. 17, the stent 50 is deformed and expanded so that the bent portion of the linear component of the stent base 20 is opened, and the adjacent connection portions 52 of each reinforcing member 51 are connected to each other. The distance between them increases, and the reinforcing member 51 formed in a straight line is deformed so as to be thinned by being stretched in the circumferential direction.

  As described above, in the stent 50 according to the third embodiment, since the reinforcing member 51 is formed over 360 degrees in the circumferential direction of the stent 50, the reinforcing member is less than 360 degrees before the stent 50 expands. Compared with the case where it forms with, the intensity | strength of the edge part of the stent 50 can be improved effectively. For this reason, the stent 50 can effectively suppress the occurrence of flaring before the stent 50 expands. When the stent 50 is expanded, the reinforcing member 51 is stretched thinly, so that the strength of reinforcement by the reinforcing member 51 is somewhat reduced, but a sufficient expansion holding force for the blood vessel can be obtained.

  In addition, the stent 50 according to the third embodiment is in a state before expansion because the reinforcing member 51 is linearly formed along the circumferential direction of the stent 50 before the stent 50 expands. The strength of the end portion of the stent 50 can be effectively improved. For this reason, generation | occurrence | production of the flare before the stent 50 expands especially can be suppressed effectively. When the stent 50 is expanded, the reinforcing member 51 is stretched thinly, so that the strength of reinforcement by the reinforcing member 51 is somewhat reduced, but a sufficient expansion holding force for the blood vessel can be obtained.

The position where the reinforcing member is connected to the annular body 23 may not be the first folded portion 23A. For example, as shown in FIG. 18, even if the reinforcing member 53 formed linearly along the circumferential direction of the stent 50 is connected to the annular portion 23 between the first folded portion 23A and the second folded portion 23B. Good.
<Fourth embodiment>

  As shown in FIG. 19, the stent 60 according to the fourth embodiment is different from the stent 10 according to the first embodiment only in the configuration of the reinforcing member 61. In addition, the same code | symbol is attached | subjected to the site | part which has the same function as 1st Embodiment, and description is abbreviate | omitted in order to avoid duplication.

  The reinforcing member 61 of the stent 60 according to the fourth embodiment is made of a biodegradable material, and is connected to the annular bodies 23 at both ends in the axial direction X of the stent base body 20. One reinforcing member 61 is provided in each of the annular bodies 23, and each reinforcing member 61 is formed to be bent 360 degrees in the circumferential direction of the stent 60. Each reinforcing member 61 includes a plurality of first curved portions 62 projecting toward the end portion of the stent 60 along the axial direction X of the stent 60 and the first curved portion 62 before the stent 60 is expanded. On the other hand, it is a linear member provided with a plurality of second curved portions 63 protruding in the opposite direction, and the first portion of the annular body 23 is connected by a connection portion 64 extending from one of the second curved portions 63 toward the stent base body 20. 1 is connected to the folded portion 23A. In the present embodiment, the number of the first bending portion 62 and the second bending portion 63 provided in each reinforcing member 61 is the same as the number of the first turning portions 23A of the annular body 23. More or less than the number of 23A. Since the reinforcing member 61 is formed of a biodegradable material, it is decomposed and disappears after the stent 60 is placed in the living body lumen.

  Next, the operation of the stent 60 according to the fourth embodiment will be described.

  When the stent 60 is expanded at the stenosis portion by the balloon 230 (see FIG. 10), the stent 60 is expanded while the stenosis portion is expanded and plastically deformed, and the shape is maintained in a state where the stenosis portion is expanded. At this time, as shown in FIG. 20, the stent 60 is deformed and expanded so that the bent portion of the linear component of the stent base 20 is opened, and the first curved portion 62 adjacent to each other in the reinforcing member 61. The distance between each other and between the second bending portions 63 is increased, and the first bending portion 62 and the second bending portion 63 are deformed into a shape closer to a straight line without becoming thin.

As described above, in the stent 60 according to the fourth embodiment, since the reinforcing member 61 protrudes long in the direction away from the stent substrate 20, as shown in FIG. ) The stent 60 can be placed so as to be in wide contact with C and the surrounding healthy part H, and the stenosis C can be surely expanded. Then, after the reinforcing member 61 is disassembled and disappears in the stable period and only the stent base 20 remains, the range in which the stent base 20 is in contact with the healthy part H is reduced as much as possible, and stent thrombosis and stent fracture (stent fracture) Occurrence of damage) can be suppressed.
<Fifth Embodiment>

  As shown in FIG. 22, the stent 70 according to the fifth embodiment is different from the stent 10 according to the first embodiment only in the configuration of the reinforcing member 71. In addition, the same code | symbol is attached | subjected to the site | part which has the same function as 1st Embodiment, and description is abbreviate | omitted in order to avoid duplication.

  The reinforcing member 71 of the stent 70 according to the fifth embodiment is made of a biodegradable material, and is connected to the annular bodies 23 at both ends in the axial direction X of the stent base body 20. One reinforcing member 71 is provided for each annular body 23, and each reinforcing member 71 is formed to be bent 360 degrees in the circumferential direction of the stent 70. Each reinforcing member 71 includes a plurality of first curved portions 72 projecting toward the end portion of the stent 70 along the axial direction X of the stent 70 and a first curved portion 72 before the stent 70 is expanded. On the other hand, the first member of the annular body 23 is a linear member including a plurality of second curved portions 73 protruding in opposite directions, and is connected to the first base portion 20 by the connecting portions 74 extending from the second curved portions 73 toward the stent base body 20. It is connected to the folded portion 23A. In the present embodiment, the number of the first bending portions 72 and the second bending portions 73 provided in each of the reinforcing members 71 matches the number of the first turning portions 23A of the annular body 23, and all the first turning portions are provided. Although the connection part 74 is connected with respect to the part 23A, the number of the connection parts 74 may be smaller than the number of the 1st folding | turning parts 23A. In this case, there exists the first folded portion 23A to which the connecting portion 74 is not connected. Since the reinforcing member 71 is formed of a biodegradable material, it is decomposed and disappears after the stent 70 is placed in the living body lumen.

  Next, the operation of the stent 70 according to the fifth embodiment will be described.

  When the stent 70 is expanded at the stenosis portion by the balloon 230 (see FIG. 10), the stent 70 is expanded while being expanded and plastically deformed, and the shape is maintained in a state where the stenosis portion is expanded. At this time, as shown in FIG. 23, the stent 70 is deformed and expanded so that the bent portion of the linear component of the stent base 20 is opened, and the first curved portions 72 adjacent to each reinforcing member 71 are expanded. The distance between each other and between the second bending portions 73 increases, and the first bending portion 72 and the second bending portion 73 are deformed into a shape closer to a straight line without becoming thin.

  As described above, in the stent 70 according to the fifth embodiment, since the reinforcing member 71 is formed over 360 degrees in the circumferential direction of the stent 70, the reinforcing member is less than 360 degrees before the stent 70 expands. Compared with the case where it forms with, the intensity | strength of the edge part of the stent 70 can be improved effectively. Furthermore, since the connection part 74 of the reinforcement member 71 is connected to the plurality of (all in this embodiment) first folded-back parts 23A, the stent 70 can further improve the strength of the end part of the stent 70. it can. For this reason, the stent 70 can effectively suppress the occurrence of flaring.

  Further, in the stent 70 according to the fifth embodiment, since the first bending portion 72 and the second bending portion 73 are formed so that the reinforcing member 71 protrudes in the axial direction X of the stent 70, the stent 70 is expanded. After that, the first bending portion 72 and the second bending portion 73 are deformed into a state closer to a straight line without becoming thin. And since the connection part 74 of the reinforcement member 71 is connected to the several 1st folding | turning part 23A (all this embodiment), the stent 70 is the state of the stent 70 in the state after the stent 70 expanded. The strength of the end portion is further improved. For this reason, the strength of the end portion of the stent 70 after expansion is increased, and a high expansion holding force for the blood vessel can be obtained.

In addition, since the reinforcing member 71 protrudes long in the direction away from the stent base body 20, the stent 70 is similar to the stent 60 according to the fourth embodiment. By placing the stent 70 so as to be in wide contact with the surrounding healthy part H, the stenosis C can be surely expanded. Then, after the reinforcing member 71 is disassembled and disappears in the stable period and only the stent base 20 remains, the range in which the stent base 20 is in contact with the healthy part H is reduced as much as possible, and stent thrombosis and stent fracture (stent fracture) Occurrence of damage) can be suppressed.
<Sixth Embodiment>

  As shown in FIG. 24, the stent 80 according to the sixth embodiment is the fourth embodiment only in that an additional reinforcing member 82 is added to the stent 60 according to the fourth embodiment (see FIG. 19). It differs from the stent 60 which concerns on this. In addition, the same code | symbol is attached | subjected to the site | part which has a function similar to 1st, 4th embodiment, and description is abbreviate | omitted in order to avoid duplication.

  The reinforcing member 81 of the stent 80 according to the sixth embodiment is made of a biodegradable material, and is connected to the annular bodies 23 at both ends in the axial direction X of the stent base body 20. Each reinforcing member 81 includes a plurality of first bending portions 62, a plurality of second bending portions 63, and one connection portion 64 connected to the first folded portion 23A of the annular body 23. An additional reinforcing member 82 that is integrally connected to the first curved portion 62 is provided. The additional reinforcing member 82 is formed integrally with the first bending portion 62, the second bending portion 63, and the connection portion 64, and is linearly formed over 360 degrees in the circumferential direction of the stent 80. Since the reinforcing member 81 is formed of a biodegradable material, it is decomposed and disappears after the stent 80 is placed in the living body lumen.

  Next, the operation of the stent 80 according to the sixth embodiment will be described.

  When the stent 80 is expanded at the stenosis by the balloon 230 (see FIG. 10), the stent 80 expands while being expanded and plastically deformed, and the shape is maintained in a state where the stenosis is expanded. At this time, as shown in FIG. 25, the stent 80 is deformed and expanded so that the bent portions of the linear components of the stent base 20 are opened, and the first curved portions 62 adjacent to each other in the reinforcing members 81 are expanded. While the distance between each other and between the second bending portions 63 increases, the first bending portion 62 and the second bending portion 63 are deformed into a shape closer to a straight line without becoming thin, and the additional reinforcing member 82 is provided. It is stretched in the circumferential direction and deformed to become thinner.

  As described above, the stent 80 according to the sixth embodiment is similar to the stent 60 according to the fourth embodiment because the reinforcing member 81 protrudes long in the direction away from the stent base body 20 as in the fourth embodiment. In addition, in the acute phase, the stent 80 can be placed so as to be in wide contact with the stenosis (lesion) C of the blood vessel and the healthy part H in the vicinity thereof, and the stenosis C can be reliably expanded. Then, after the reinforcing member 81 is disassembled and disappears in the stable period and only the stent base 20 remains, the range in which the stent base 20 is in contact with the healthy portion H is reduced as much as possible, and stent thrombosis and stent fracture (stent fracture) Occurrence of damage) can be suppressed.

Furthermore, in the stent 80 according to the sixth embodiment, the reinforcing member 81 is linearly formed along the circumferential direction of the stent 80 in a state before the stent 80 is expanded. The strength of the end portion of the stent 50 can be effectively improved. For this reason, generation | occurrence | production of the flare before the stent 50 expands can be suppressed effectively.
<Seventh embodiment>

  As shown in FIG. 26, the stent 90 according to the seventh embodiment is the fourth embodiment only in that an additional reinforcing member 92 is added to the stent 60 according to the fourth embodiment (see FIG. 19). It differs from the stent 60 which concerns on this. In addition, the same code | symbol is attached | subjected to the site | part which has a function similar to 1st, 4th embodiment, and description is abbreviate | omitted in order to avoid duplication.

  The reinforcing member 91 of the stent 90 according to the seventh embodiment is made of a biodegradable material, and is connected to the annular bodies 23 at both ends in the axial direction X of the stent base body 20. Each reinforcing member 91 includes a plurality of first bending portions 62, a plurality of second bending portions 63, and one connection portion 64 connected to the first folded portion 23A of the annular body 23. An additional reinforcing member 92 that is integrally connected to the first curved portion 62 is provided. The additional reinforcing member 92 is formed integrally with the first bending portion 62, the second bending portion 63, and the connection portion 64, and is formed over 360 degrees in the circumferential direction of the stent 90. The additional reinforcing member 92 is formed with a third curved portion 93 that protrudes in a direction away from the stent base 20 between the portions connected to the first folded portion 23A. Since the reinforcing member 91 is formed of a biodegradable material, it is decomposed and disappears after the stent 90 is placed in the living body lumen.

  Next, the operation of the stent 90 according to the seventh embodiment will be described.

  When the stent 90 is expanded at the stenosis portion by the balloon 230 (see FIG. 10), the stent 90 is expanded while the stenosis portion is expanded and plastically deformed, and the shape is maintained in a state where the stenosis portion is expanded. At this time, as shown in FIG. 27, the stent 90 is deformed and expanded so that the bent portion of the linear component of the stent base 20 is opened, and the first curved portion 62 adjacent in each reinforcing member 91 is expanded. The distance between each other and between the second bending portions 63 is increased, and the first bending portion 62 and the second bending portion 63 are deformed into a shape closer to a straight line without becoming thin. Furthermore, the stent 90 is deformed into a shape closer to a straight line without the third curved portion 93 of the additional reinforcing member 92 becoming thin.

  As described above, the stent 90 according to the seventh embodiment is similar to the stent 60 according to the fourth embodiment because the reinforcing member 91 protrudes long in the direction away from the stent base body 20 as in the fourth embodiment. In addition, in the acute phase, the stent 90 can be placed so as to be in wide contact with the stenosis part (lesion part) C of the blood vessel and the healthy part H around it, and the stenosis part C can be surely expanded. Then, after the reinforcing member 91 is disassembled and disappears in the stable period and only the stent base 20 remains, the range in which the stent base 20 is in contact with the healthy part H is reduced as much as possible, and stent thrombosis and stent fracture (stent fracture) Occurrence of damage) can be suppressed.

Furthermore, after the stent 90 expands, the stent 90 is deformed into a state closer to a straight line without the first curved portion 62, the second curved portion 63, and the third curved portion 93 of the reinforcing member 91 becoming thin. For this reason, the strength of the end portion of the stent 90 after expansion is increased, and a high expansion holding force for the blood vessel can be obtained.
<Eighth Embodiment>

  As shown in FIG. 28, the stent 100 according to the eighth embodiment is provided only in that a connection portion 102 having a structure different from that of the connection portion 64 is provided in the stent 80 according to the sixth embodiment (see FIG. 24). Different from the stent 80 according to the sixth embodiment. In addition, the same code | symbol is attached | subjected to the site | part which has the same function as 1st, 4th and 6th embodiment, and description is abbreviate | omitted in order to avoid duplication.

  The reinforcing member 101 of the stent 100 according to the eighth embodiment is made of a biodegradable material, and is connected to the annular bodies 23 at both ends in the axial direction X of the stent base body 20. Each of the reinforcing members 101 includes a plurality of first bending portions 62, a plurality of second bending portions 63, an additional reinforcing member 82, and connection portions 102 connected to all the first folded portions 23A of the annular body 23. It has. The connecting portion 102 is formed integrally with the first bending portion 62, the second bending portion 63, and the additional reinforcing member 82, and is linearly formed over 360 degrees in the circumferential direction of the stent 100. Since the reinforcing member 101 is formed of a biodegradable material, it is decomposed and disappears after the stent 100 is placed in the living body lumen.

  Next, the operation of the stent 100 according to the eighth embodiment will be described.

  When the stent 100 is expanded at the stenosis portion by the balloon 230 (see FIG. 10), the stent 100 is expanded while the stenosis portion is expanded and plastically deformed, and the shape is maintained in a state where the stenosis portion is expanded. At this time, as shown in FIG. 29, the stent 100 is deformed and expanded so that the bent portions of the linear components of the stent base 20 are opened, and the first curved portions 62 adjacent to each other in the reinforcing members 101 are expanded. The distance between each other and between the second bending portions 63 is increased, and the first bending portion 62 and the second bending portion 63 are deformed into a shape closer to a straight line without becoming thin. Furthermore, in the stent 100, the distance between the adjacent first curved portions 62 and the distance between the second curved portions 63 is increased, so that the additional reinforcing member 82 and the connecting portion 102 that are formed in a straight line are surrounded. It is stretched in the direction and deformed to become thin.

  As described above, the stent 100 according to the eighth embodiment is the same as the stent 80 according to the sixth embodiment because the reinforcing member 101 protrudes long in the direction away from the stent base 20 as in the sixth embodiment. Furthermore, in the acute phase, the stent 100 can be placed so as to be in wide contact with the stenosis part (lesion part) C of the blood vessel and the healthy part H in the vicinity thereof, and the stenosis part C can be reliably expanded. Then, after the reinforcing member 101 is disassembled and disappears in the stable period and only the stent base 20 remains, the range in which the stent base 20 is in contact with the healthy part H is reduced as much as possible, and stent thrombosis and stent fracture (stent fracture) Occurrence of damage) can be suppressed.

Furthermore, in the stent 100 according to the eighth embodiment, the reinforcing member 101 is formed over 360 degrees in the circumferential direction of the stent 100, and the additional reinforcing member 82 and the connecting portion 102 are formed linearly in the circumferential direction. In the state before the stent 60 expands, the strength of the end portion of the stent 100 can be improved very effectively. For this reason, the stent 100 can very effectively suppress the occurrence of flaring.
<Ninth Embodiment>

  As shown in FIG. 30, the stent 110 according to the ninth embodiment is only provided in the stent 90 according to the seventh embodiment (see FIG. 26) in that a connection portion 112 having a structure different from that of the connection portion 64 is provided. Different from the stent 90 according to the seventh embodiment. In addition, the same code | symbol is attached | subjected to the site | part which has the same function as 1st, 4th and 7th embodiment, and description is abbreviate | omitted in order to avoid duplication.

  The reinforcing member 111 of the stent 110 according to the ninth embodiment is made of a biodegradable material, and is connected to the annular bodies 23 at both ends in the axial direction X of the stent base body 20. Each reinforcing member 111 includes a plurality of first bending portions 62, a plurality of second bending portions 63, an additional reinforcing member 92 in which a third bending portion 93 is formed, and all first folded portions of the annular body 23. And a connection part 112 connected to 23A. The connecting portion 112 is formed integrally with the first bending portion 62, the second bending portion 63, and the additional reinforcing member 92, and is formed in a straight line over 360 degrees in the circumferential direction of the stent 110. Since the reinforcing member 111 is formed of a biodegradable material, it is decomposed and disappears after the stent 110 is placed in the living body lumen.

  Next, the operation of the stent 110 according to the ninth embodiment will be described.

  When the stent 110 is expanded at the stenosis portion by the balloon 230 (see FIG. 10), the stent 110 expands while the stenosis portion is expanded and plastically deformed, and the shape is maintained in a state where the stenosis portion is expanded. At this time, as shown in FIG. 31, the stent 110 is deformed and expanded so that the bent portion of the linear component of the stent base 20 is opened, and the first curved portion 62 adjacent to each reinforcing member 111 is expanded. The distance between each other and between the second bending portions 63 is increased, and the first bending portion 62 and the second bending portion 63 are deformed into a shape closer to a straight line without becoming thin. Further, in the stent 110, the distance between the adjacent first curved portions 62 and the distance between the second curved portions 63 is increased, so that the additional reinforcing member 82 and the connecting portion 112 that are formed in a straight line are surrounded. It is stretched in the direction and deformed to become thin.

  As described above, the stent 110 according to the ninth embodiment is the same as the stent 90 according to the seventh embodiment because the reinforcing member 111 protrudes long in the direction away from the stent base body 20 as in the seventh embodiment. In addition, in the acute phase, the stent 110 can be placed so as to be in wide contact with the stenosis part (lesion part) C of the blood vessel and the healthy part H in the vicinity thereof, and the stenosis part C can be surely expanded. Then, after the reinforcing member 111 is disassembled and disappears in the stable period and only the stent base 20 remains, the range in which the stent base 20 is in contact with the healthy portion H is reduced as much as possible, and stent thrombosis and stent fracture (stent fracture) Occurrence of damage) can be suppressed.

  Furthermore, in the stent 110 according to the ninth embodiment, after the stent 110 is expanded, the first curved portion 62, the second curved portion 63, and the third curved portion 93 of the reinforcing member 111 are closer to a straight line without becoming thin. Transforms into For this reason, the strength of the end portion of the stent 110 after expansion is increased, and a very high expansion holding force for the blood vessel can be obtained.

  Note that the present invention is not limited to the above-described embodiments, and various modifications can be made by those skilled in the art within the technical idea of the present invention. For example, the stent substrate is not limited to the configuration described above. Therefore, the stent substrate may not be formed of one spiral wire, but may be formed by arranging two or more wires in parallel. In addition, the stent base may be configured such that endless (ring-shaped) annular bodies are arranged in the axial direction X of the stent and adjacent annular bodies are connected, instead of being spiral.

  The stent may be a closed cell structure or may be a self-expanding stent that expands by its own elastic force.

10 stent,
20 stent substrate;
10, 40, 50, 60, 70, 80, 90, 100, 110 stent,
28 covering part,
43, 52, 64, 74, 102, 112 connections,
30, 41, 51, 53, 61, 71, 81, 91, 101, 111 reinforcing member,
32 first end,
33 second end,
42 curved part,
62, 72 1st bending part,
63, 73 second bending portion,
82,92 additional reinforcing members,
93 third bending portion,
X-axis direction.

Claims (7)

A stent base formed of a linear component and formed in a cylindrical shape having a gap as a whole, and deformable to expand radially outward; and
A stent formed of a biodegradable material and having at least one linear reinforcing member connected to at least one of the linear components located at both axial ends of the stent substrate.   The stent according to claim 1, wherein the reinforcing member is formed in a range of less than 360 degrees in a circumferential direction of the stent.   The stent according to claim 1, wherein the reinforcing member is formed over 360 degrees in a circumferential direction of the stent.   The stent according to any one of claims 1 to 3, wherein a rough surface having a rougher surface than other portions is formed at a portion connected to the reinforcing member of the linear component.   5. The material according to claim 1, wherein a portion of the linear component connected to the reinforcing member is coated with a material having a higher affinity for the reinforcing member than a material constituting the linear component. The stent according to claim 1.   The stent according to any one of claims 1 to 5, wherein the reinforcing member has a portion that is bent so as to protrude in an axial direction of the stent in a state before the stent is expanded.   The stent according to any one of claims 1 to 6, wherein the reinforcing member has a portion that is linearly formed along a circumferential direction of the stent in a state before the stent is expanded.

Images