JP5243080B2 - In vivo indwelling stent and biological organ dilator - Google Patents

Description

  The present invention relates to an in-vivo indwelling stent and a biological organ dilator used to improve a stenosis or occlusion in a biological lumen such as a blood vessel, a bile duct, a trachea, an esophagus, or a urethra.

In-vivo stents are used to expand the stenosis or occlusion site and secure the lumen to treat various diseases caused by stenosis or occlusion of blood vessels or other in-vivo lumens. In general, it is a tubular medical device.
Since the stent is inserted into the body from outside the body, the diameter is small at that time. The stent is expanded at the target stenosis or occlusion site to increase the diameter, and the lumen is held as it is.

As the stent, a metal wire or a cylindrical shape obtained by processing a metal tube is generally used. It is attached to a catheter or the like in a thin state, inserted into a living body, expanded by a certain method at a target site, and tightly fixed to the inner wall of the lumen to maintain the lumen shape. Stents are classified into self-expandable stents and balloon expandable stents according to function and placement method. The balloon expandable stent has no expansion function in the stent itself. After inserting the stent into the target site, the balloon is positioned in the stent to expand the balloon, and the stent is expanded (plastic deformation) by the expansion force of the balloon. Fix it in close contact with the inner surface of the lumen. This type of stent requires the above-described stent expansion operation.
The purpose of stent placement is to prevent and reduce restenosis that occurs after a procedure such as PTCA. And in recent years, a bioactive substance is carried on the stent so that the bioactive substance can be locally released over a long period of time at the indwelling site of the lumen to reduce the restenosis rate. .
For example, Japanese Patent Application Laid-Open No. 8-33718 (Patent Document 1) discloses a stent in which the surface of a stent body is coated with a mixture of a substance for treatment and a polymer, and Japanese Patent Application Laid-Open No. 9-56807 (Patent Document). In 2), a stent is proposed in which a drug layer is provided on the surface of the stent body, and a biodegradable polymer layer is provided on the surface of the drug layer.
As a result of intensive studies by the inventor of the present application, it has been found that there may be a cause of restenosis in the vasodilation retention strength (strength) possessed by the stent. However, a stent having a low vascular expansion retention force cannot sufficiently improve the vascular stenosis at the time of placement.
Japanese Patent Laid-Open No. 2002-200196 (Patent Document 3) discloses a tubular biological duct stent which is a knitted or braided fabric of bioabsorbable fibers and does not have fiber ends. Further, Patent Document 3 discloses that the intersection is bonded by a synthetic water-soluble polymer, a natural water-soluble polymer, a synthetic bioabsorbable polymer, or a natural bioabsorbable polymer. Are disclosed.

JP-A-8-33718 JP-A-9-56807 JP 2002-200196 A

Since the stent of Patent Document 3 is formed of a knitted or braided woven fabric of bioabsorbable fibers, it can be absorbed by the living body in the long term, so that the stent can be placed again. However, since the stent is a knitted or braided woven fabric, the vasodilation retention force at the time of indwelling is not sufficient, and the stenosis site may not be improved satisfactorily.
An object of the present invention is to maintain a sufficient small diameter state maintaining force in a compressed state for insertion into a living body lumen, and to have a sufficient vasodilation holding force at the time of stent placement, Since the fibers forming the stent substrate can be satisfactorily improved and the living body absorbs the fibers forming the stent substrate, the in-vivo stent can be placed again and the living organ can be expanded. A device is provided.

What achieves the above object is as follows.
(1) It is formed in a substantially tubular body, has an outer diameter for insertion into a lumen in a living body, and expands by applying a force that spreads in the radial direction from the inside, and adheres to the tissue in the living body. A stent for in-vivo placement, wherein the stent is woven or knitted by a plurality of fibers extending obliquely with respect to the central axis of the stent, and with respect to the axial direction of the stent. A plurality of fiber crossing portions where the fibers cross obliquely, and a crossing portion fixing member provided at all of the plurality of fiber crossing portions or a plurality of the fiber crossing portions of the plurality of fiber crossing portions, The fibers are formed of a biodegradable material, and the cross-section fixing member is plastically deformed following the deformation of the fiber cross-section when the stent is expanded, and Is intended to hold a variation of the fiber cross section, further, the intersecting portion fixing member is indwelling stent having a radiopaque.
(2) The stent becomes a small diameter state for insertion into a living body lumen by being compressed, and expands by applying a force spreading in the radial direction from the inside, and adheres to the tissue in the living body. The stent for in-vivo indwelling, wherein the intersecting portion fixing member is deformed along with the deformation of the fiber intersecting portion when the stent is compressed, and is deformed following the deformation of the fiber intersecting portion when the stent is expanded. The stent for indwelling in a living body according to the above (1).
(3) The stent has a large number of annular fiber intersections arranged in an axial direction of the stent so that at least three of the fiber intersections are substantially annular with respect to the central axis of the stent. At least a plurality of the annular fiber intersecting portion rows of the annular fiber intersecting portion rows of the at least two fixing member possessing fiber intersecting portions that possess the intersecting portion fixing member and at least one that does not possess the intersecting portion fixing member. The in vivo indwelling stent according to (1) or (2), comprising two fixing member non-retaining fiber intersections.
(4) The stent has a plurality of axial fiber crossing rows in which the plurality of fiber crossing portions are aligned substantially in the axial direction of the stent, and the stent has the crossing portion fixing member. Any one of the above (1) to (3), comprising a plurality of fixed member possessing axial fiber intersecting portion rows and a plurality of fixing member non-retaining axial fiber intersecting portion rows not retaining the intersecting portion fixing member. The stent for in-vivo indwelling.

(5) The stent has a large number of annular fiber intersections arranged in the axial direction of the stent, the plurality of fiber intersections being substantially annular with respect to the central axis of the stent, The said stent is equipped with the fixed member holding | circulation cyclic | annular fiber crossing part row | line | column which hold | maintains the said cross | intersection fixing member, and the fixing member non-holding cyclic | annular fiber crossing part row | line | column which does not hold | maintain the said crossing part fixing member alternately (1) Thru | or the stent for indwelling in any one of (4).
(6) The in vivo indwelling stent according to any one of (1) to (5), wherein the intersecting portion fixing member includes four fiber gripping portions that grip each of the intersecting fibers at two positions. .
(7) The raw material according to any one of (1) to (6), wherein a holding member that suppresses separation of the crossing portion fixing member from the fiber crossing portion is fixed to each crossing portion fixing member. Indwelling stent.
(8) The in-vivo indwelling stent according to any one of (1) to (7), wherein the material for forming the intersection fixing member is a plastic deformable metal or a plastic deformable resin.

(9) The in-vivo indwelling stent according to any one of (1) to (8), wherein the intersection fixing member covers an outer surface and / or an inner surface of the fiber intersection.
(10) The in-vivo stent according to any one of (1) to (9), wherein the fiber carries a physiologically active substance.
(11) The indwelling stent according to any one of (1) to (10), wherein the fiber carries a physiologically active substance only in a portion where the crossing portion fixing member is not provided.
(12) The in-vivo indwelling stent according to (10) or (11), wherein the intersection fixing member does not carry the physiologically active substance.

( 13 ) The indwelling stent according to any one of (1) to ( 12 ), wherein the biodegradable material is a biodegradable metal or a biodegradable polymer.
( 14 ) The in vivo indwelling stent according to ( 13 ), wherein the biodegradable metal is pure magnesium or a magnesium alloy.
( 15 ) The biodegradable polymer is selected from the group consisting of polyglycolic acid, polylactic acid, polycaprolactone, polyhydroxybutyric acid, cellulose, polyhydroxybutyrate valeric acid, polysaccharides, polysalicylic acid, and polyorthoesters The in-vivo indwelling stent according to the above ( 13 ), which is at least one, or a copolymer, mixture, or composite thereof.

What achieves the above object is as follows.
( 16 ) A tube-shaped shaft main body, a foldable and expandable balloon provided at the distal end of the shaft main body, and the balloon in a folded state are mounted so as to enclose the balloon. A biological organ dilating instrument comprising the stent according to any one of (1) to ( 15 ), which is expanded by expansion.

The in-vivo stent according to the present invention is woven or knitted by a plurality of fibers extending obliquely with respect to the central axis of the stent, and has a large number of crossing obliquely with respect to the axial direction of the stent. And a crossing portion fixing member provided at all or a plurality of fiber crossing portions of the multiple fiber crossing portions. The fiber is formed of a biodegradable material, and the crossing fixing member is plastically deformed following the deformation of the fiber crossing when the stent is expanded, and maintains the deformation form of the fiber crossing. Yes.
For this reason, in the compressed state for insertion into the living body lumen, plastic deformation is performed following the deformation of the fiber crossing portion. Therefore, sufficient compressive state maintaining force is retained in the compressed state, and at the time of stent placement. At the time of expansion of a certain stent, since the deformed form at the time of expansion is held by the cross-section fixing member that has been plastically deformed at the time of expansion of a certain stent, a sufficient vasodilation retention force can be exhibited and the stenosis can be improved satisfactorily. Furthermore, since the fiber constituting the main part of the stent is formed of a biodegradable material, it is absorbed into the living body and disappears after a predetermined period of time, so that the stent can be placed again.

The in-vivo indwelling stent of the present invention will be described using the following preferred embodiments.
FIG. 1 is a front view of an expanded state of an in-vivo stent according to an embodiment of the present invention. FIG. 2 is a development view of the in-vivo stent of FIG. FIG. 3 is a partially enlarged view of FIG. FIG. 4 is an enlarged view for explaining the vicinity of the intersection fixing member in FIG. 3. FIG. 5 is an enlarged view for explaining a back surface state in the vicinity of the intersection fixing member in FIG. 4. 6 is an enlarged cross-sectional view taken along line AA of FIG. FIG. 7 is a front view of the in-vivo indwelling stent shown in FIG. FIG. 8 is a development view of FIG. FIG. 9 is an enlarged view for explaining the vicinity of the intersection fixing member in FIG.

The indwelling stent 1 of the present invention is formed into a substantially tubular body, has an outer diameter for insertion into a living body lumen, and expands by applying a force that spreads radially from the inside. In addition, the stent is in close contact with the in vivo tissue.
The stent 1 is woven or knitted by a plurality of fibers 3 extending obliquely with respect to the central axis of the stent 1. The stent 1 includes a large number of fiber intersections 4 in which fibers intersect obliquely with respect to the axial direction of the stent 1 and a plurality of fiber intersections 4 of all or a large number of fiber intersections 4. And a crossing portion fixing member 5 provided on the head. The fiber 3 is made of a biodegradable material. Further, the crossing portion fixing member 5 follows the deformation of the crossing portion 4 when the stent 1 is expanded and is plastically deformed, and holds the deformation form of the crossing portion 4.

The stent 1 of this embodiment includes a stent base 2 woven or knitted into a cylindrical shape by fibers 3 and a large number of crossing fixing members 5 fixed to fiber crossing parts 4 of the stent base 2.
As shown in FIGS. 1 and 2, the stent substrate 2 is composed of a plurality of fibers 3 wound in a spiral shape (oblique with respect to the central axis of the stent 1). The stent base 2 of this embodiment is spirally wound in the same direction (in other words, is wound so as to be substantially parallel), and is wound in the opposite direction to the plurality of fibers 3. In addition, a plurality of fibers 3 woven with the above-described fibers are used. And the stent base | substrate is provided with many fiber crossing parts 4 which a fiber cross | intersects. Since the fiber 3 is wound spirally (obliquely with respect to the central axis of the stent 1), the fiber intersection 4 is an intersection where the fibers intersect obliquely with respect to the axial direction of the stent 1. Yes. The stent base 2 is preferably knitted with fibers as described above, but may be a net-like one.

  The spacing between adjacent fibers is preferably 0.05 to 2 mm for a stent having an outer diameter of about 4 mm, for example. The distance between the closest fiber intersections is preferably 0.1 to 4 mm. Moreover, it is preferable that it is 0.1-2 mm as a distance between the fiber crossing parts adjacent to the circumferential direction of a stent.

The fiber 3 is preferably a single fiber, a plurality of fiber bundles, or a stranded wire of a plurality of fibers. In the case of a fiber bundle, it is preferably a bundle of 2 to 3 fibers. Moreover, in the case of a twisted fiber, it is preferably a twisted wire of 2 to 3 fibers. Furthermore, as shown in FIG. 6, the fibers 3 (3a, 3b) preferably have a substantially elliptical or substantially rectangular cross-sectional shape. In this case, the fiber is preferably such that the minor axis of the cross section faces the central axis direction of the stent.
And the fiber 3 which comprises the stent base | substrate 2 is formed with the biodegradable material.

As the biodegradable material, a biodegradable metal or a biodegradable polymer is preferably used.
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, polyhydroxybutyrate valeric acid, polysalicylic acid, polypeptide, polysaccharide, chitin, chitosan and the like can be used.
Moreover, the fiber may carry a physiologically active substance. In this case, the fiber may carry a physiologically active substance only in a portion where a crossing portion fixing member described later is not provided. Moreover, the intersection fixing member described later may not carry a physiologically active substance. As a method for supporting the physiologically active substance on the fiber, it can be carried out by coating on the surface of the fiber or adding it to the fiber-forming material.

  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. As the biological material, for example, EGF (epidermal growth factor), VEGF (vascular endothelial growth factor), HGF (hepatocyte growth factor), PDGF (platelet derived growth factor), bFGF (basic fibroblast growth factor) and the like are preferable.

And the stent 1 of this Example is provided with the cross | intersection fixing | fixed member 5 provided in the some fiber cross | intersection part 4 of all the many fiber cross | intersection parts 4 or many fiber cross | intersection parts 4. FIG.
In addition, the stent 1 of this embodiment is compressed to be in a small diameter state for insertion into a living body lumen, and expands by applying a force spreading radially from the inside, so that in vivo tissue The cross-section fixing member 5 is deformed in accordance with the deformation of the fiber cross-section 4 during compression for mounting the stent 1 on the balloon, and is expanded when the stent 1 is expanded (balloon of the balloon). At the time of expansion, when a force spreading in the radial direction from the inside of the stent is applied), the deformation of the fiber intersection 4 is followed and re-deformed.
The intersecting portion fixing member 5 is formed of a material having higher plastic deformability than the forming material of the fiber 3 and plastically deforms following the deformation of the intersecting portion 4 when the stent 1 is expanded. It is meant to hold.

The material for forming the crossing fixing member 5 is preferably a metal or a resin that is more plastically deformable than the material for forming the fiber 3.
Examples of the easily plastically deformable metal include stainless steel, tantalum or tantalum alloy, platinum or platinum alloy, gold or gold alloy, cobalt base alloy, cobalt chromium alloy, titanium alloy, niobium alloy and the like. Moreover, after producing the stent shape, precious metal plating (gold, platinum) may be performed. As stainless steel, SUS316L having the most corrosion resistance is suitable.

  Examples of the easily plastically deformable resin include polyolefin (for example, polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, a mixture of polypropylene and polyethylene or polybutene), polyester (for example, polyethylene terephthalate, polybutylene terephthalate), Polyamide (for example, 6 nylon, 66 nylon), polycarbonate, acrylic resin (for example, polymethyl methacrylate, polyacrylamide, acrylonitrile-styrene copolymer, acrylonitrile-butadiene-styrene copolymer), styrene resin (for example, polystyrene) , Methacrylate-styrene copolymer, methacrylate-butylene-styrene copolymer) and the like. Further, at least one selected from the group consisting of biodegradable polymers having plastic deformability, such as polyglycolic acid, polylactic acid, polycaprolactone, polyhydroxybutyric acid, cellulose, polyhydroxybutyrate valeric acid, and polyorthoesters Or these copolymers, a mixture, or a composite may be sufficient.

  Furthermore, it is preferable that the intersection fixing member 5 has contrast properties. As the contrast property, either X-ray contrast property or ultrasonic contrast property may be used. For example, the formation of the crossing portion fixing member is made of a material having a contrasting property, the addition of a material having a contrasting property to the forming material of the crossing fixing member, or the crossing portion fixing member. The film can be formed by forming a film with a contrasting material on the surface of the film. As the contrast material, a contrast medium such as platinum or platinum alloy, gold or gold alloy, or contrast medium such as barium sulfate, bismuth oxide or tungsten powder is used.

And in the stent 1 of this Example, the stent 1 and the stent base | substrate 2 have a form as shown in FIG.1 and FIG.2 in the expansion state and the state before compression, and in a compression state (diameter reduction state) 7 and FIG. 8 are used.
In this stent 1, the stent substrate 2 has a large number of annular fiber intersections arranged in the axial direction of the stent 1, in which at least three fiber intersections 4 are substantially annular with respect to the central axis of the stent 1. Yes. In particular, in the illustrated stent 1, each annular fiber intersection row has a plurality (specifically, eight) fiber intersection portions 4 so as to be substantially equiangular with respect to the central axis of the stent 1. Yes. The number of fiber crossing portions 4 in the annular fiber crossing row is preferably about 3 to 16, and particularly preferably 6 to 12. The stent 1 has a large number (specifically, 40) of this annular fiber intersection portion row substantially parallel to the axial direction of the stent 1. The number of annular fiber intersecting portion rows in the stent 1 is preferably about 10 to 60. Preferably, it is 20-40. In adjacent annular fiber intersection rows, the fiber intersections are shifted in the circumferential direction of the stent. Further, in every other annular fiber intersection row, each fiber intersection 4 is arranged substantially linearly in the axial direction of the stent.

And at least some annular fiber intersection part row | line | column of many annular fiber intersection part row | line | columns is at least 2 fixed member holding | maintenance fiber intersection part which hold | maintains an intersection fixing member, and at least 1 which does not hold an intersection fixing member It is preferable that a fixing member non-holding fiber intersection is provided.
The stent 1 of the embodiment shown in FIGS. 1, 2, 7, and 8 includes a plurality of annular fiber crossing rows that hold crossing fixing members 5. The plurality of annular fiber crossing rows that hold the crossing portion fixing members 5 do not include the fixing members 5 at all crossing portions, but have at least two fixing member holding fiber crossing portions and crossing portion fixing members. At least one fixed member non-retaining fiber intersection is not provided. Further, the intersecting fibers are not fixed at the intersection where the fixing member is not held. Thus, by having the fixing member non-holding intersection, it is easy to deform from the compressed state (diameter-reduced state) shown in FIGS. 7 and 8 to the expanded state and the pre-compressed state shown in FIGS. 1 and 2. It is supposed to be. Moreover, by having the fixing member non-holding intersection, it is easy to deform from the expanded state and the pre-compression state shown in FIGS. 1 and 2 to the compressed state (diameter-reduced state) shown in FIGS. It is said.

  The stent 1 of this embodiment includes a fixed member-carrying annular fiber intersection part row that holds the intersection fixing member 5 and a fixed member non-owner annular fiber intersection part row that does not hold the intersection fixing member. And in the fixed member possessing annular fiber intersection part row, the fixed member possessing intersection part and the fixing member non-holding intersection part are alternated, and half of the intersecting parts forming the annular fiber intersection part row serve as the fixing member 5. The remaining half of the intersections 4 do not have a fixing member. Furthermore, in the stent 1 of this embodiment, the fixing member-carrying annular fiber intersection part row and the fixing member non-holding annular fiber intersection part row not holding the intersection fixing member are alternately provided. For this reason, the stent is easily deformed from the compressed state (diameter-reduced state) to the expanded state and the pre-compression state. Further, the expansion state and the pre-compression state can be easily changed to the compression state (diameter reduction state).

  Further, the stent 1 of this embodiment also has a plurality of axial fiber crossing rows in which a plurality of fiber crossing portions are aligned substantially in the axial direction of the stent 1. The stent 1 includes a plurality of axially-fixed-member-holding fiber intersections that hold the crossing-fixing members, and a plurality of axial-fixing-member-non-holding fiber crossing rows that do not hold the crossing-fixing members. ing. Moreover, the axial direction fixing member possessing fiber intersection part row | line | column is a thing which is not adjacent. In particular, in the stent 1 of this embodiment, a plurality (specifically, three) of axial fixing member non-holding fiber crossing rows are provided between two axial fixing member holding fiber crossing rows. Yes. Moreover, in the stent 1 of this Example, the axial direction fixing member possessing fiber intersection part row | line | column is equipped with a fixing member in all the intersection parts. However, it is not limited to such a thing.

  3, 4, and 6, the intersection fixing member 5 includes four fiber gripping portions 51, 52, 53, and 54 that grip each of the intersecting fibers 3 a and 3 b at two locations. I have. Moreover, the crossing portion fixing member covers the outer surface of the fiber crossing portion. As shown in FIGS. 5 and 6, the crossing portion fixing member 5 in this embodiment is configured so that each fiber gripping portion 51, 52, 53, 54 has a holding portion for holding a fiber (specifically, Claw portions) 56, 57, 58, 59. In this fixing member 5, the back surface of the fiber intersection 4 is exposed. As shown in FIG. 6, the fibers 3 a and 3 b intersect within the fixing member 5.

  Then, in the compressed state of the stent, the fiber intersection 4 and the intersection fixing member 5 are deformed as shown in FIG. That is, when the state shown in FIG. 4 is changed to the state shown in FIG. 9, the fiber crossing portion 4 has a direction in which the angle of the fiber crossing angle facing the axial direction of the fiber crossing portion 4 becomes narrow and the circumferential direction of the fiber crossing portion 4. Deforms in a direction where the angle of the fiber crossing angle facing to becomes wider. Following this, the fixing member 5 also has a fiber gripper 51 and a fiber gripper 54 adjacent to the fiber gripper 51 in the circumferential direction, a fiber gripper 52 and a fiber gripper adjacent to the fiber gripper 52 in the circumferential direction. A fiber between the fiber gripper 51 and the fiber gripper 51 that is adjacent to the fiber gripper 51 in the axial direction, and between the fiber gripper 54 and the fiber gripper 54 that is adjacent to the fiber gripper 54 in the axial direction. It deforms in the direction in which the space between the gripping portions 53 becomes wider. When the stent is expanded, the state shown in FIG. 9 is re-deformed into the state shown in FIG. 4 or a state close thereto.

  Moreover, as a cross | intersection part fixing member, you may have a back surface form as shown in FIG. FIG. 10 is an enlarged view for explaining the back surface state in the vicinity of the crossing portion fixing member of the in-vivo stent according to another embodiment of the present invention. FIG. 11 is an enlarged sectional view taken along line BB in FIG.

  The fixing member 50 of this embodiment has the same surface form as that shown in FIG. The fixing member 50 covers both the outer surface and the inner surface of the fiber intersection 4. Specifically, as shown in FIGS. 10 and 11, the fixing member 50 includes a front surface side member 50 a and a back surface side member 50 b fixed to the front surface side member 50 a, and the fiber crossing portion 4 includes the fixing member 50. Stored inside. The fixing member 50 also includes fiber gripping portions 51, 52, 53, and 54, and the fiber gripping portions 51, 52, 53, and 54 are cylindrical portions.

  Further, the crossing portion fixing member may be as shown in FIGS. FIG. 12 is an enlarged view for explaining a front state in the vicinity of the crossing portion fixing member of the in-vivo stent according to another embodiment of the present invention. FIG. 13 is an enlarged view for explaining the back surface state in the vicinity of the crossing portion fixing member of the stent shown in FIG. 14 is an enlarged cross-sectional view taken along the line CC of FIG.

  The basic form of the fixing member 60 of this embodiment is the same as that of the fixing member 5 described above. The difference is that the intersection fixing member 60 suppresses the separation of the intersection fixing member main body 61 from the fiber intersection 4. The holding member 62 is fixed. The intersection fixing member main body 61 has the same configuration as the fixing member 5 described above. The holding member 62 is a ring-shaped member fitted to the fixing member main body 61, as shown in FIGS. 12 to 14, and is attached to a portion recessed inward in the circumferential direction of the fixing member 61. As shown in FIGS. 13 and 14, the back surface has two claw portions 62 a and 62 b for pressing the fiber crossing portion. By providing such a holding member, it is possible to reliably prevent the fixing member from being detached when the fiber crossing portion is deformed.

  And in the stent of all the above-mentioned examples, the diameter when the stent is not expanded is preferably about 0.35 to 3.0 mm, and more preferably 0.5 to 1.5 mm. The length of the stent when not expanded is preferably about 8 to 200 mm. The diameter of the stent when it is expanded is preferably about 1.0 to 10 mm. Further, the length when the stent is expanded is preferably about 8 to 200 mm.

Next, the vasodilator of the present invention will be described with reference to the embodiments shown in the drawings.
FIG. 15 is a front view of a living organ dilator according to an embodiment of the present invention. FIG. 16 is an enlarged view of the distal end portion of the living organ dilator shown in FIG. FIG. 17 is an explanatory diagram for explaining the operation of the living organ dilator according to the embodiment of the present invention.

The living organ dilator 100 of the present invention encloses a tubular shaft body 102, a foldable and expandable balloon 103 provided at the distal end of the shaft body 102, and a balloon 103 in a folded state. And a stent 1 that is expanded by expansion of the balloon 103.
And as the stent 1, the stent 1 mentioned above and the stent of all the examples mentioned above can be used.
A living organ expanding device 100 of this embodiment includes the above-described stent 1 and a tube-shaped living organ expanding device main body 101 to which the stent 1 is attached.

The living organ expanding instrument main body 101 includes a tube-shaped shaft main body 102 and a foldable and expandable balloon 103 provided at the distal end of the shaft main body. The stent 1 includes the balloon 103 in a folded state. It is mounted so as to be encapsulated and expanded by expansion of the balloon 103.
As the stent 1, the stents of all the embodiments described above can be used. The stent used here is a so-called balloon expandable stent that has a diameter for insertion into a lumen in a living body and is expandable when a force that expands radially from the inside of the tubular body is applied. Used.

In the living organ dilator 100 of this embodiment, as shown in FIG. 17, the shaft main body 102 has one end opened at the tip of the shaft main body 102 and the other end at the rear end of the shaft main body 102. An opening guide wire lumen 115 is provided.
The living organ expanding instrument main body 101 includes a shaft main body 102 and a stent expansion balloon 103 fixed to the distal end of the shaft main body 102, and the stent 1 is mounted on the balloon 103. The shaft body 102 includes an inner tube 112, an outer tube 113, and a branch hub 110.

  As shown in FIG. 16, the inner tube 112 is a tube body including a guide wire lumen 115 for inserting a guide wire therein. The inner tube 112 has a length of 100 to 2500 mm, more preferably 250 to 2000 mm, and an outer diameter of 0.1 to 1.0 mm, more preferably 0.3 to 0.7 mm, and a wall thickness of 10 to 10. It is 250 micrometers, More preferably, it is 20-100 micrometers. The inner tube 112 is inserted into the outer tube 113, and the tip of the inner tube 112 protrudes from the outer tube 113. A balloon expanding lumen 116 is formed by the outer surface of the inner tube 112 and the inner surface of the outer tube 113, and has a sufficient volume. The outer tube 113 is a tube body in which the inner tube 112 is inserted and the tip is located at a portion slightly retracted from the tip of the inner tube 112.

The outer tube 113 has a length of 100 to 2500 mm, more preferably 250 to 2000 mm, and an outer diameter of 0.5 to 1.5 mm, more preferably 0.7 to 1.1 mm, and a wall thickness of 25 to 25 mm. It is 200 μm, more preferably 50 to 100 μm.
In the living organ dilator 100 of this embodiment, the outer tube 113 is formed by the distal end side outer tube 113a and the main body side outer tube 113b, and both are joined. The distal end side outer tube 113a has a tapered diameter at a portion closer to the distal end than the joint portion with the main body side outer tube 113b, and the distal end side has a smaller diameter than the tapered portion.
The outer diameter at the small diameter portion of the distal end side outer tube 113a is 0.50 to 1.5 mm, preferably 0.60 to 1.1 mm. Further, the base end portion of the distal end side outer tube 113a and the outer diameter of the main body side outer tube 113b are 0.75 to 1.5 mm, preferably 0.9 to 1.1 mm.

The balloon 103 has a front end side joint portion 103a and a rear end side joint portion 103b. The front end side joint portion 103a is fixed at a position slightly rear end side from the front end of the inner tube 112, and the rear end side joint portion 103b. Is fixed to the tip of the outer tube. The balloon 103 communicates with the balloon expansion lumen 116 in the vicinity of the proximal end portion.
As a material for forming the inner tube 112 and the outer tube 113, a material having a certain degree of flexibility is preferable. For example, polyolefin (for example, polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, etc.) Further, thermoplastic resins such as polyvinyl chloride, polyamide elastomer and polyurethane, silicone rubber, latex rubber and the like can be used, preferably the above-mentioned thermoplastic resin, more preferably polyolefin.

As shown in FIG. 16, the balloon 103 is foldable, and can be folded on the outer periphery of the inner tube 112 when not expanded. As shown in FIG. 16, the balloon 103 has an expandable portion that is a cylindrical portion (preferably, a cylindrical portion) having substantially the same diameter so that the attached stent 1 can be expanded. The substantially cylindrical portion may not be a perfect cylinder, but may be a polygonal column. As described above, the balloon 103 is liquid-tightly fixed to the inner tube 112 with the front end side joint portion 103a and the rear end side joint portion 103b to the front end of the outer tube 113 with an adhesive or heat fusion. . Further, in this balloon 103, the space between the expandable portion and the joint portion is formed in a tapered shape.
The balloon 103 forms an expansion space 103 c between the inner surface of the balloon 103 and the outer surface of the inner tube 112. The expansion space 103c communicates with the expansion lumen 116 on the entire periphery at the rear end. In this way, the rear end of the balloon 103 communicates with the expansion lumen having a relatively large volume, so that the expansion fluid can be reliably injected into the balloon from the expansion lumen 116.

  As a material for forming the balloon 103, a material having a certain degree of flexibility is preferable. For example, polyolefin (for example, polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, cross-linked ethylene-vinyl acetate). Copolymer), polyvinyl chloride, polyamide elastomer, polyurethane, polyester (for example, polyethylene terephthalate), thermoplastic resin such as polyarylene sulfide (for example, polyphenylene sulfide), silicone rubber, latex rubber, and the like. In particular, a stretchable material is preferable, and the balloon 103 is preferably biaxially stretched having high strength and expansion force.

  As the size of the balloon 103, the outer diameter of the cylindrical portion (expandable portion) when expanded is 2 to 4 mm, preferably 2.5 to 3.5 mm, and the length is 10 to 300 mm, preferably 20-250 mm. Moreover, the outer diameter of the front end side joint portion 103a is 0.9 to 1.5 mm, preferably 1 to 1.3 mm, and the length is 1 to 5 mm, preferably 1 to 1.3 mm. Moreover, the outer diameter of the rear end side joint portion 103b is 1 to 1.6 mm, preferably 1.1 to 1.5 mm, and the length is 1 to 5 mm, preferably 2 to 4 mm.

As shown in FIGS. 16 and 17, the living organ dilator 100 has two Xs fixed to the outer surface of the shaft main body at positions corresponding to both ends of the cylindrical portion (expandable portion) when expanded. Line contrast members 117 and 118 are provided. In addition, it is good also as what has two X-ray contrast contrast members fixed to the outer surface of the shaft main-body part 102 (in this embodiment, the inner pipe | tube 112) of the position which becomes the both ends of the predetermined length of the center part of the stent 1. FIG. Furthermore, it is good also as what provides the single X-ray contrast property member fixed to the outer surface of the shaft main-body part of the position used as the center part of a stent.
The X-ray contrast members 117 and 118 are preferably ring-shaped members having a predetermined length, or those obtained by winding a linear body in a coil shape, and the forming material is, for example, gold, platinum, tungsten, or the like. Those alloys or silver-palladium alloys are suitable.

The stent 1 is attached so as to encapsulate the balloon 103. The stent is made with an inner diameter that is smaller than when the stent is expanded and larger than the outer diameter of the folded balloon. Then, a balloon is inserted into the manufactured stent, and a uniform force is applied to the outer surface of the stent inward to reduce the diameter, thereby forming a product-state stent. That is, the above stent 1 is completed by compression mounting on the balloon.
A linear rigidity imparting body (not shown) may be inserted between the inner tube 112 and the outer tube 113 (within the balloon expansion lumen 116). The rigidity imparting body prevents extreme bending of the main body 102 of the living organ expanding device 100 at the bent portion without significantly reducing the flexibility of the living organ expanding device 100, and the distal end of the living organ expanding device 100. Easy to push the part. It is preferable that the tip of the rigidity imparting body has a smaller diameter than other parts by a method such as polishing. In addition, it is preferable that the distal end of the small diameter portion of the rigidity imparting body extends to the vicinity of the distal end portion of the main body outer tube 113. The rigidity imparting body is preferably a metal wire, and is preferably an elastic metal such as stainless steel having a wire diameter of 0.05 to 1.50 mm, preferably 0.10 to 1.00 mm, a superelastic alloy, etc. Is a high-strength stainless steel for springs and a superelastic alloy wire.

In the living organ dilator 100 of this embodiment, as shown in FIG. 15, a branch hub 110 is fixed to the proximal end. The branch hub 110 has a guide wire inlet 109 that communicates with the guide wire lumen 115 to form a guide wire port, and communicates with the inner tube hub fixed to the inner tube 112 and the balloon expansion lumen 116, and the injection port 111. And an outer tube hub fixed to the outer tube 113. The outer tube hub and the inner tube hub are fixed to each other. As a material for forming the branch hub 110, a thermoplastic resin such as polycarbonate, polyamide, polysulfone, polyarylate, and methacrylate-butylene-styrene copolymer can be preferably used.
Note that the structure of the living organ dilator is not limited to the above, and may have a guide wire insertion port communicating with the guide wire lumen at an intermediate portion of the living organ dilator.

FIG. 1 is a front view of an expanded state of an in-vivo stent according to an embodiment of the present invention. FIG. 2 is a development view of the in-vivo stent of FIG. FIG. 3 is a partially enlarged view of FIG. FIG. 4 is an enlarged view for explaining the vicinity of the intersection fixing member in FIG. 3. FIG. 5 is an enlarged view for explaining a back surface state in the vicinity of the intersection fixing member in FIG. 4. 6 is an enlarged cross-sectional view taken along line AA of FIG. FIG. 7 is a front view of the in-vivo indwelling stent shown in FIG. FIG. 8 is a development view of FIG. FIG. 9 is an enlarged view for explaining the vicinity of the intersection fixing member in FIG. FIG. 10 is an enlarged view for explaining the back surface state in the vicinity of the crossing portion fixing member of the in-vivo stent according to another embodiment of the present invention. FIG. 11 is an enlarged sectional view taken along line BB in FIG. FIG. 12 is an enlarged view for explaining a front state in the vicinity of the crossing portion fixing member of the in-vivo stent according to another embodiment of the present invention. FIG. 13 is an enlarged view for explaining the back surface state in the vicinity of the crossing portion fixing member of the stent shown in FIG. 14 is an enlarged cross-sectional view taken along the line CC of FIG. FIG. 15 is a front view of a living organ dilator according to an embodiment of the present invention. FIG. 16 is an enlarged view of the distal end portion of the living organ dilator shown in FIG. FIG. 17 is an explanatory diagram for explaining the operation of the living organ dilator according to the embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Stent for in-vivo placement 2 Stent base | substrate 3,3a, 3b Fiber 4 Fiber crossing part 5 Crossing part fixing member

Claims (16)

In-vivo indwelling that is formed into a substantially tubular body, has an outer diameter for insertion into a lumen in a living body, and expands by applying a force that expands in the radial direction from the inside, and adheres to the tissue in the living body A stent,
The stent is woven or knitted with a plurality of fibers extending obliquely with respect to the central axis of the stent, and a large number of the fibers intersect with each other obliquely with respect to the axial direction of the stent. A fiber crossing portion and a crossing fixing member provided at all of the plurality of fiber crossing portions or a plurality of the fiber crossing portions of the plurality of fiber crossing portions, and the fiber is a biodegradable material. The crossing portion fixing member is formed by plastic deformation following the deformation of the fiber crossing portion during expansion of the stent, and maintains the deformation form of the fiber crossing portion, and further, the crossing portion The in-vivo indwelling stent , wherein the fixing member has a contrast property . The stent is compressed into a small diameter state for insertion into a lumen in a living body, and is expanded by applying a force that expands in a radial direction from the inside, and is placed in the living body in close contact with tissue in the living body. The crossing portion fixing member is deformed along with the deformation of the fiber crossing portion when the stent is compressed, and re-deforms following the deformation of the fiber crossing portion when the stent is expanded. The in-vivo stent according to claim 1. The stent has a plurality of annular fiber intersections arranged in an axial direction of the stent so that at least three of the fiber intersections are substantially annular with respect to the central axis of the stent. At least a plurality of the annular fiber intersection portions of the fiber intersection portion rows include at least two fixing member holding fiber intersection portions that hold the intersection fixing member and at least one fixing member that does not hold the intersection fixing member. The in-vivo indwelling stent according to claim 1 or 2, comprising a non-retaining fiber intersection. The stent has a plurality of axial fiber crossing rows in which the plurality of fiber crossing portions are aligned substantially in the axial direction of the stent, and the stent has a plurality of crossing portion fixing members. The in-vivo indwelling device according to any one of claims 1 to 3, comprising a fixed member-carrying axial fiber intersection part row and a plurality of fixing member non-holding axial fiber intersection parts row not holding the intersection fixing member. Stent. The stent has a plurality of annular fiber intersecting rows arranged in an axial direction of the stent so that the plurality of fiber intersecting portions are substantially annular with respect to the central axis of the stent, and the stent further includes: The fixing member-carrying annular fiber intersection part row holding the intersection part fixing member and the fixing member non-holding annular fiber intersection part row not holding the intersection part fixing member are alternately provided. The stent for in-vivo indwelling. The in vivo indwelling stent according to any one of claims 1 to 5, wherein the intersecting portion fixing member includes four fiber gripping portions that grip each of the intersecting fibers at two positions. The indwelling stent according to any one of claims 1 to 6, wherein a holding member that suppresses detachment of the intersection fixing member from the fiber intersection is fixed to each of the intersection fixing members. The in-vivo indwelling stent according to any one of claims 1 to 7, wherein a forming material of the intersection fixing member is a plastic deformable metal or a plastic deformable resin. The in-vivo indwelling stent according to any one of claims 1 to 8, wherein the intersection fixing member covers an outer surface and / or an inner surface of the fiber intersection. The in-vivo stent according to any one of claims 1 to 9, wherein the fiber carries a physiologically active substance. The in-vivo stent according to any one of claims 1 to 10, wherein the fiber carries a physiologically active substance only in a portion where the crossing portion fixing member is not provided. The in-vivo indwelling stent according to claim 10 or 11, wherein the intersection fixing member does not carry the physiologically active substance. The in-vivo stent according to any one of claims 1 to 12 , wherein the biodegradable material is a biodegradable metal or a biodegradable polymer. The in-vivo stent according to claim 13 , wherein the biodegradable metal is pure magnesium or a magnesium alloy. The biodegradable polymer is at least one selected from the group consisting of polyglycolic acid, polylactic acid, polycaprolactone, polyhydroxybutyric acid, cellulose, polyhydroxybutyrate valeric acid, polysaccharides, polysalicylic acid, and polyorthoesters. Or the stent for in-vivo of Claim 13 which is these copolymers, a mixture, or a composite. A tubular shaft main body, a foldable and expandable balloon provided at the distal end of the shaft main body, and a balloon mounted so as to enclose the balloon in a folded state and expanded by expansion of the balloon A biological organ dilating device comprising the stent according to any one of claims 1 to 15 .

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