Stents for blood vessels

• US 7,326,240 B1
• Filed: 11/30/1999
• Issued: 02/05/2008
• Est. Priority Date: 11/30/1998
• Status: Expired due to Fees

• Current Assignee: Veryan Medical Limited (Otsuka Holdings Company Limited)
• Original Assignee: Imperial College of Science Technology & Medicine (Imperial College London)
• Inventors: Mclean, Mary Anne, Doorly, Denis Joseph, Caro, Colin Gerald
• Primary Examiner(s): Prebilic; Paul B.
• Application Number:
  US09/857,012
• Time in Patent Office: 2,989 Days
• Field of Search: 623/1.15, 623/1.16, 623/1.19, 623/1.3, 623/1.31, 623/1.22, 606/153
• US Class Current: 623/1.15
• CPC Class Codes: A61B 17/11 for performing anastomosis; Buttons for anastomosis
• CPC Class Codes: A61B 17/12 for ligaturing or otherwise compressing tubular parts of the body, e.g. blood vessels, umbilical cord specially adapted for vas deferens or fallopian tubes A61F6/20; materials for ligaturing blood vessels A61L17/00
• CPC Class Codes: A61B 2017/00867 shape memory effect
• CPC Class Codes: A61B 2017/1107 for blood vessels
• CPC Class Codes: A61B 2017/1135 End-to-side connections, e.g. T- or Y-connections
• CPC Class Codes: A61B 5/0263 using NMR
• CPC Class Codes: A61B 5/027 using catheters
• CPC Class Codes: A61B 8/06 Measuring blood flow measuring volume flow in general G01F, e.g. G01F1/66, G01F1/72; measuring speed of fluids in general G01P5/00
• CPC Class Codes: A61B 8/12 in body cavities or body tracts, e.g. by using catheters catheters per se A61M25/00
• 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 2/86 Stents in a form characterised by the wire-like elements; Stents in the form characterised by a net-like or mesh-like structure
• CPC Class Codes: A61F 2/89 the wire-like elements comprising two or more adjacent rings flexibly connected by separate members
• CPC Class Codes: A61F 2/90 characterised by a net-like or mesh-like structure
• CPC Class Codes: A61F 2/91 made from perforated sheet material or tubes, e.g. perforated by laser cuts or etched holes
• CPC Class Codes: A61F 2/94 Stents retaining their form, i.e. not being deformable, after placement in the predetermined place
• CPC Class Codes: A61F 2002/30014 differing in elasticity, stiffness or compressibility
• CPC Class Codes: A61F 2002/30199 Three-dimensional shapes
• CPC Class Codes: A61F 2210/0076 multilayered, e.g. laminated structures
• CPC Class Codes: A61F 2220/0075 sutured, ligatured or stitched, retained or tied with a rope, string, thread, wire or cable
• CPC Class Codes: A61F 2230/0054 V-shaped
• CPC Class Codes: A61F 2230/0063 : Three-dimensional shapes
• CPC Class Codes: A61F 2250/0029 : differing in bending or flexure capacity
• CPC Class Codes: A61F 2250/0096 : Markers and sensors for detecting a position or changes of a position of an implant, e.g. RF sensors, ultrasound markers

Abstract

A stent for supporting part of a blood vessel includes a supporting portion around which or within which part of an intact blood vessel, other than a graft, can be placed so that the stent internally or externally supports that part of the blood vessel. The supporting portion of the stent is of a shape and/or orientation whereby flow within the vessel is caused to follow a non-planar curve. By maintaining a non-planar curvature in the vessel itself, favorable blood flow velocity patterns can be achieved through the generation in the vessel of a swirl flow. Failures in such vessels through diseases such as thrombosis, atherosclerosis, intimal hyperplasia or through blockage, kinking or collapse, can be significantly reduced.

Claims

1. A stent for insertion into a vessel, which stent includes a supporting portion around which part of an intact vessel other than a graft can be placed, so that the stent internally supports an interior wall of that vessel part, wherein the supporting portion comprises a hollow tube, the walls of which have openings therein so that when the stent is inserted in a vessel the interior wall of the vessel is exposed via said openings to fluid flow along the vessel, and wherein the supporting portion of the stent, when in the vessel, has a non-planar, at least partially helical shape wherein a central axis of the hollow tube forms a non-planar three-dimensional at least partially helical shape and the hollow tube is capable of imposing said three-dimensional at least partially helical shape on a central axis of the vessel, whereby fluid flow within the stent supported part of the vessel follows the three-dimensional at least partially helical shape to induce swirl flow.

2. A stent as claimed in claim 1 wherein the supporting portion of the stent is fabricated to incorporate a non-planar curved form.

3. A stent as claimed in claim 1 which is of generally hollow tubular shape with three-dimensional curvature.

4. A stent as claimed in claim 1 in the form of an open lattice generally tubular framework with discrete openings at each end thereof.

5. A stent as claimed in claim 1 in combination with a device which assists in monitoring the condition of the vessel.

6. A stent as claimed in claim 5 wherein the device is a sensor adapted to transmit a signal responsive to one or more internal flow conditions.

7. A stent as claimed in claim 6 in which the sensor is ring-shaped and is electrically connected to a remote module incorporating power supply, signal detection and recording means.

8. A stent as claimed in claim 6 wherein the sensor is adapted to transmit signals which can be monitored by at least one of ultrasound, magnetic resonance imaging and electron spin resonance imaging techniques.

9. A stent as claimed in claim 6 wherein the sensor portion forms an integral part of the stent and the means of excitation and signal detection are entirely extracorporeal.

10. A stent according to claim 1 which is adapted to flex three dimensionally but which has sufficient torsional stiffness to induce and maintain in use the non-planar curvature.

11. A stent as claimed in claim 1 fabricated from a shape memory alloy.

12. A stent as claimed in claim 1 fabricated from a linked mesh or series of linked wire members which is coiled or partly coiled or helical or partly helical.

13. A stent for insertion into a vessel, comprising:

a pre-shaped flexible supporting portion which supports an interior wall of the vessel and is capable of imposing a shape thereon, comprising;

a hollow tube including a wall,

a plurality of openings located in the wall of the tube so that the interior wall of the vessel is exposed, via said openings, to fluid flow along the vessel, and

wherein the hollow tube is pre-shaped so as to have an at least partially helical shape, wherein a central axis of the hollow tube forms a non-planar three-dimensional at least partially helical shape and the hollow tube is capable of imposing said three-dimensional at least partially helical shape on a central axis of the vessel, so that a swirling fluid flow is induced within the vessel.

14. The stent of claim 13 further comprising a sensor operatively connected to said hollow tube, said sensor being adapted to transmit a signal responsive to one or more internal flow conditions.

15. A stent for insertion into a blocked, constricted or otherwise flow restricted vessel, comprising:

a hollow tube which is capable of supporting an interior wall of the vessel;

a plurality of openings located in the wall of the tube so that the interior wall of the vessel is exposed, via said openings, to fluid flow along the vessel; and

,

wherein said hollow tube is pre-shaped so as to have an at least partially helical shape, and wherein a central axis of the hollow tube forms a non-planar three-dimensional at least partially helical shape and the hollow tube is capable of imposing said three-dimensional at least partially helical shape on a central axis of the vessel so that a swirling fluid flow is induced within the vessel.

16. The stent of claim 15 wherein said hollow tube creates a generally uniform distribution of fluid flow wall shear stress within the hollow tube.

17. A stent for insertion into a blocked, constricted or otherwise flow restricted vessel, comprising:

a hollow tube, including a plurality of openings located in a wall thereof such that an interior wall of the vessel is capable of being exposed to fluid flow along the vessel when the hollow tube is inserted into the vessel, wherein the hollow tube is capable of supporting the interior wall of the vessel; and

,

wherein said hollow tube is pre-shaped so as to have an at least partially helical shape, and wherein a central axis of the hollow tube forms a non-planar three-dimensional at least partially helical shape and the hollow tube is capable of imposing said three-dimensional at least partially helical shape on a central axis of the vessel so that a swirling fluid flow is induced within the vessel.

18. The stent of claim 17 wherein said hollow tube comprises a shape memory alloy.