VALVED STENT, BASE MATERIAL FOR FORMING VALVED STENT, AND METHOD FOR PRODUCING VALVED STENT

• US 20150119970A1
• Filed: 01/07/2015
• Published: 04/30/2015
• Est. Priority Date: 09/09/2011
• Status: Active Grant

• Current Assignee: National Cerebral And Cardiovascular Center, Shinkan Kogyo K.K.
• Original Assignee: National Cerebral And Cardiovascular Center, Shinkan Kogyo K.K.
• Inventors: NAKAYAMA, Yasuhide, OIE, Tomonori
• Granted Patent: US 9,956,074 B2
• Time in Patent Office: Days
• US Class Current: 623/1.13
• CPC Class Codes: A61F 2/07 Stent-grafts
• CPC Class Codes: A61F 2/2412 with soft flexible valve members, e.g. tissue valves shaped like natural valves check valves with flexible valve members in general F16K15/14
• CPC Class Codes: A61F 2/2415 Manufacturing methods
• CPC Class Codes: A61F 2/2418 Scaffolds therefor, e.g. support stents
• CPC Class Codes: A61F 2/2475 Venous valves
• CPC Class Codes: A61F 2/82 Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents stent-grafts for tubular structures of the body other than blood vessels A61F2/04; stent-grafts for blood vessels A61F2/07; instruments specially adapted for placement or removal of stents or stent-grafts A61F2/95; for closing wounds, or holding wounds closed A61B17/04 - A61B17/115; dilators A61M29/00
• CPC Class Codes: A61F 2002/061 provided with means for allowing access to secondary lumens
• CPC Class Codes: A61F 2002/072 Encapsulated stents, e.g. wire or whole stent embedded in lining
• CPC Class Codes: A61F 2230/0054 V-shaped
• CPC Class Codes: A61F 2240/001 Designing or manufacturing processes
• CPC Class Codes: A61F 2240/004 Using a positive or negative model, e.g. moulds
• CPC Class Codes: B32B 1/00 Layered products having a non-planar shape
• CPC Class Codes: Y10T 428/2933 Coated or with bond, impregnation or core

Abstract

The present invention provides a valved stent that can provide a valve function without blocking a branch blood vessel, and also can provide a valve function with minimum covering of blood vessel tissue in a stent indwelling section. Specifically, a cylindrical stent body 4 is provided. A leaflet 5 that can open/close a blood vessel 2 in a blood flow direction is provided. The leaflet 5 is composed of connective tissue and protrudes radially inward from the stent body 4. An inside and an outside of the stent body 4 radially communicate with each other. The stent does not block a branch blood vessel 8. An area of the blood vessel covered with the stent is reduced.

Claims

1. A base material for forming a valved stent that is placed in an environment with a body tissue material to form film-like tissue on a surface of the base material and form a valved stent including a leaflet protruding radially inward from a stent body, comprising:

a columnar base material body;

a plurality of recesses formed in an outer peripheral surface of the base material body;

an inner cover that covers the recesses to form a leaflet forming space for forming the leaflet; and

an outer cover placed on an outer surface side of the inner cover with the stent body interposed therebetween.

2. The base material for forming a valved stent according to claim 1, wherein the inner cover and the outer cover have open sections that expose a boundary between the plurality of recesses in the outer peripheral surface of the base material body via the stent body.

3. The base material for forming a valved stent according to claim 1, further comprising a positioning section that circumferentially positions the base material body, the inner cover, and the outer cover.

4. A method for producing a valved stent comprising:

an assembly step of assembling a base material for forming the valved stent according to claim 1 by incorporating a stent body between an inner cover and an outer cover;

a placement step of placing the base material for forming the valved stent in an environment with a body tissue material;

a formation step of forming film-like tissue around the base material for forming the valved stent;

a taking-out step of taking out the base material for forming the valved stent covered with tissue from the environment; and

a separation step of integrally delaminating and taking out tissue including the leaflet and the stent body from the base material for forming the valved stent as a valved stent,

wherein the separation step is a step of removing tissue on surfaces of opposite ends of the base material for forming the valved stent and the outer cover, detaching the outer cover, and then central-axially disassembling and taking out the base material body and the inner cover from a lumen of the valved stent.

5. A base material for forming a valved stent that is placed in an environment with a body tissue material to form film-like tissue on a surface of the base material and form a reverse valved stent with an inside and an outside being reversed of a valved stent including a leaflet protruding radially inward from a stent body, comprising:

a columnar base material body; and

a base material cover placed on an outer peripheral side of the base material body with the stent body interposed therebetween.

6. The base material for forming a valved stent according to claim 5, wherein the base material cover has an open section that exposes the outer peripheral surface of the base material body via the stent body.

7. The base material for forming a valved stent according to claim 6, wherein the outer peripheral surface of the base material body has an entry groove that connective tissue enters, and the base material cover is placed so that the entry groove is aligned with the open section.

8. The base material for forming a valved stent according to claim 5, wherein the base material cover has a bulge formed by expanding an outer surface side.

9. A method for producing a valved stent comprising:

an assembly step of assembling a base material for forming the valved stent according to claim 5 by incorporating a stent body between a base material body and a base material cover;

a placement step of placing the base material for forming the valved stent in an environment with a body tissue material;

a formation step of forming film-like tissue around the base material for forming the valved stent;

a taking-out step of taking out the base material for forming the valved stent covered with tissue from the environment; and

a separation step of integrally delaminating and taking out tissue including the leaflet and the stent body from the base material for forming the valved stent as a reverse valved stent,

wherein the separation step is a step of removing tissue on opposite ends of the base material for forming the valved stent, then central-axially disassembling the base material body and the base material cover, taking out the base material cover from between the leaflet and the stent body, and taking out the base material body from a lumen of the reverse valved stent, and

the method further comprises, after the separation step, a reverse step of reversing an inside and an outside of the reverse valved stent to form a valved stent.