Removable covering for implantable frame projections

• US 20070100432A1
• Filed: 10/19/2006
• Published: 05/03/2007
• Est. Priority Date: 10/24/2005
• Status: Active Grant

• Current Assignee: Cook Medical Incorporated (Cook Group Incorporated)
• Original Assignee: Cook Incorporated (Cook Group Incorporated)
• Inventors: Agnew, Charles, Case, Brian
• Granted Patent: US 7,563,277 B2
• Time in Patent Office: Days
• US Class Current: 623/1.150
• CPC Class Codes: A61F 2/06 Blood vessels
• CPC Class Codes: A61F 2/2418 Scaffolds therefor, e.g. support stents
• CPC Class Codes: A61F 2/2475 Venous valves
• CPC Class Codes: A61F 2/848 having means for fixation to the vessel wall, e.g. barbs
• CPC Class Codes: A61F 2220/0016 with sharp anchoring protrusions, e.g. barbs, pins, spikes
• CPC Class Codes: A61F 2230/0026 trapezoidal
• CPC Class Codes: A61F 2230/0054 V-shaped
• CPC Class Codes: A61F 2230/0095 Saddle-shaped

Abstract

Medical devices for implantation in a body vessel, and methods of using and making the same, are provided. A medical device can include a frame with one or more projections each having at least one edge extending from the surface of the frame, and a biocompatible, water-soluble removable material coated over at least a portion of the at least one edge. The projections can be barbs positioned to engage the interior wall of a body vessel or to attach a material, such as a valve leaflet or graft, to the frame. The removable material can be dissolved within a body vessel upon implantation, thereby exposing the at least one edge. Methods of making an implantable medical device and methods of treating a subject are also disclosed.

Claims

1. A medical device for implantation in a body vessel, comprising:

an implantable frame having a surface and a plurality of projections extending from the surface, the plurality of projections each having at least one beveled edge and including a first projection comprising a first beveled edge, the first projection having a cross-sectional area at the intersection of the projection and the surface that is less than about 10 mm²; and

a biocompatible removable material covering a first portion of the surface of the implantable frame including the first edge of the first projection.

2. The medical device of claim 1, wherein the removable material is water-soluble.

3. The medical device of claim 1, wherein the plurality of projections is configured as barbs configured to engage the wall of a body vessel.

4. The medical device of claim 1, wherein the plurality of projections have a substantially triangular, substantially square, substantially rectangular, substantially elliptical, or substantially semi-circular cross-sectional shape at the base of the projection.

5. The medical device of claim 1, wherein the first portion of the surface of the implantable frame has a surface area that is less than about 10 mm².

6. The medical device of claim 1, wherein the surface of the implantable frame further comprises a second portion that is not covered by the removable material and does not include a projection.

7. The medical device of claim 1, wherein the plurality of projections are configured as barbs enclosed by a removable material covering.

8. The medical device of claim 1, wherein the removable material covering is between about 1 μ

m and 1 mm thick.

9. The medical device of claim 1, wherein the implantable frame has a tubular configuration that is moveable from a radially compressed state to a radially expanded state.

10. The medical device of claim 6, wherein the second portion of the surface of the implantable frame has a surface area that is at least about 1 mm².

11. The medical device of claim 1, wherein the implantable frame comprises a material selected from the group consisting of:

a nickel-titanium alloy, a cobalt-chromium alloy, and stainless steel.

12. The medical device of claim 1, wherein the medical device is an implantable valve further comprising at least one valve leaflet attached to the implantable frame, the implantable frame comprising a plurality of struts and bends defining a substantially cylindrical lumen and having a plurality of projections configured as barbs attached to the implantable frame.

13. The medical device of claim 1, wherein the medical device is an implantable valve further comprising at least one valve leaflet attached to the implantable frame, the implantable frame comprising a plurality of struts and bends defining a substantially cylindrical lumen and having a plurality of projections configured as barbs attached to the implantable frame;

wherein the removable material is coated on a first portion of the surface of the implantable frame that comprises the first projection, and the removable coating is not coated on a second portion of the surface of the implantable frame;

wherein the plurality of projections are configured as barbs covered by separate portions of the removable material, the plurality of barbs each having a substantially triangular, substantially elliptical, substantially square, substantially rectangular, or substantially semi-circular cross-sectional shape at the base of the projection;

wherein the plurality of projections each have a cross-sectional area at the intersection of the projection and the surface that is less than about 10 mm²;

wherein the removable material covering is between about 10 μ

m and 1 mm thick;

wherein the removable material is selected from the group consisting of;

cellulose, methylcellulose, ethyl cellulose, hydroxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxypropylmethyl cellulose, hydroxypropyl methyl cellulose (MPMC), carboxymethyl cellulose, cellulose acetophthalate, cellulose acetate, cellulose acetate phthalate (CAP), hydroxypropyl methylcellulose phthalate (HPMCP), hydroxyethyl cellulose, and hydroxypropyl methylcellulose acetate succinate (HPMCAS), chondroitin sulfate, polyvinylpyrolidone (PVP), polyvinyl alcohol (PVA), polyacrylamide, poly(methylvinyl ether), polyacrylic acid, polyethyleneoxide, poly(ethylene glycol) (PEG), mannitol, pullulan, chitin, chitosan, pectin, elsinan, maltodextrin, amylose, high amylose starch, hydroxypropylated high amylase starch, gum arabic, guar gum, locust bean gum, carrageenan gum, acacia, karaya, ghatti, tragacanth agar, tamarind gum, xanthan gum, gelatin, propylene glycol alginate, sodium alginate, carrageenan, konjac, arabinoglactan, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) and aldonic acid; and

wherein the implantable frame is moveable from a radially compressed state to a radially expanded state; and

the implantable frame comprises a material selected from the group consisting of;

a nickel-titanium alloy, a cobalt-chromium alloy, and stainless steel.

14. The medical device of claim 1, wherein the medical device is configured as a stent comprising:

an implantable frame comprising a plurality of struts and bends defining a substantially cylindrical lumen and having a surface and plurality of projections configured as barbs extending from the surface of the implantable frame;

the plurality of projections each having at least one beveled edge, and including a first projection comprising a first sharp beveled edge;

the implantable frame moveable from a radially compressed state to a radially expanded state;

wherein the implantable frame is balloon expandable or self-expanding from the compressed state to the expanded state; and

a biocompatible water-soluble removable material covering the first edge of the first projection.

15. The medical device of claim 14, wherein the removable material covering is present on a first portion of the frame with a thickness of between about 10 μ

m and 1 mm and wherein the removable material is not coated on a second portion of the surface of the implantable frame.

16. The medical device of claim 14, wherein the plurality of projections each intersect the surface of the implantable frame with a cross-sectional area that is less than about 10 mm².

17. The medical device of claim 1, wherein the medical device is configured as an implantable valve comprising:

an implantable frame having a surface and a plurality of projections extending from the surface, the plurality of projections each having at least one beveled edge, the plurality of pointed projections including a first projection comprising a first sharp beveled edge;

the implantable frame comprising a plurality of struts and bends defining a substantially cylindrical lumen;

a biocompatible and water-soluble removable material covering the first edge of the first projection; and

at least one valve leaflet attached to the implantable frame.

18. The medical device of claim 17, wherein the removable material has a thickness of between about 10 μ

m and 1 mm;

wherein the plurality of projections each intersect the surface of the implantable frame with a cross-sectional area that is less than about 10 mm².

19. A method of treating a subject comprising the steps of:

providing an intralumenal medical device comprising an implantable frame having a surface and a plurality of projections extending from the surface, the plurality of projections each having at least one beveled edge, the plurality of pointed projections including a first projection comprising a first beveled edge and a biocompatible and water-soluble removable material covering the first beveled edge of the first projection, the intralumenal medical device being moveable from a radially compressed to a radially expanded configuration;

introducing the intralumenal medical device within a body vessel in the radially compressed configuration;

positioning the intralumenal medical device at a point of treatment within the body vessel;

dissolving at least a portion of the water-soluble removable material within the body vessel to expose the first beveled edge of the first projection; and

radially expanding the intralumenal medical device at the point of treatment to the radially expanded configuration in a manner effective to engage the wall of the body vessel with the first beveled edge of the first projection.

20. A method of manufacturing an implantable medical device comprising the steps of:

providing an implantable frame having a surface having a first surface portion comprising a projection each having at least one beveled edge and a second surface portion that does not include a projection; and

applying a biocompatible water-soluble removable material to the first surface portion to cover the beveled edge of the projection, without coating the second surface portion of the implantable frame surface.