Medical implant and method of making

• US 5,192,311 A
• Filed: 08/13/1990
• Issued: 03/09/1993
• Est. Priority Date: 04/25/1988
• Status: Expired due to Fees

• Current Assignee: Angeion Corporation (Niterra Co., Ltd.)
• Original Assignee: Angeion Corporation (Niterra Co., Ltd.)
• Inventors: Kane, Lawrence M., King, Wendell L., Adams, Theodore P.
• Primary Examiner(s): ISABELLA, DAVID J
• Application Number:
  US07/566,257
• Time in Patent Office: 939 Days
• Field of Search: 623/1, 623/11, 623/12, 623/66, 606/153, 606/151, 600/36
• US Class Current: 600/36
• CPC Class Codes: A61F 2/062 Apparatus for the production of blood vessels made from natural tissue or with layers of living cells prostheses made from natural tissue or living cells A61L27/507
• CPC Class Codes: A61F 2310/00161 Carbon; Graphite
• CPC Class Codes: A61L 27/08 Carbon ; Graphite
• CPC Class Codes: A61L 27/14 Macromolecular materials
• CPC Class Codes: A61L 27/16 obtained by reactions only involving carbon-to-carbon unsaturated bonds
• CPC Class Codes: A61L 27/18 obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
• CPC Class Codes: A61L 27/50 Materials characterised by their function or physical properties , e.g. injectable or lubricating compositions, shape-memory materials, surface modified materials
• CPC Class Codes: A61L 31/04 Macromolecular materials
• CPC Class Codes: C08L 23/12 Polypropene
• CPC Class Codes: C08L 75/04 Polyurethanes
• CPC Class Codes: Y10S 623/921 Blood vessel

Abstract

The method of generating a homograft includes preparing a prosthesis composed of a tubular substrate. The substrate is open at each end to permit blood to flow along the length of the substrate inside wall. The substrate is selected to have at least one thrombogenic surface or a thrombogenic mesh material supported by the substrate. The prosthesis is inserted in the lumen of a blood vessel, either a vein or artery, of a living body and anchored in the lumen of the vessel to prevent the substrate from moving along the vessel with the blood flow. The body generates collagenous growth on the thrombogenic surface of the substrate while the substrate is freely suspended in the blood flow of the vessel. The substrate is then removed from the vessel after which a tubular homograft of collagenous tissue is removed from the substrate.

Claims

1. The method of growing a homograft in a vessel having a lumen of sufficient size to accommodate a foreign body and carrying blood flow in a living body which comprises the steps of:

a. making an incision in a vessel;

b. inserting a tubular substrate into the vessel;

c. said substrate having an inside surface and an outside surface, said substrate having a first open end and a second open end to permit blood flow along said inside surface at least one of said surfaces being thrombogenic to promote growth of collagenous tissue on said thrombogenic surface;

d. said tubular substrate having an outside diameter at said outside surface no greater than the diameter of the lumen of said vessel;

e. positioning said tubular substrate in said vessel to permit blood flow through said substrate from said first end to said second end and along said inside surface;

f. anchoring said first end to prevent said substrate from moving with the flow of blood in said vessel, said anchor leaving said second end free to move within said vessel;

g. leaving said substrate suspended in the blood flow of said vessel for a sufficient time for collagenous tissue generated by said body to form on the thrombogenic surface and form a homograft;

h. removing said substrate from said vessel;

i. removing said homograft from said substrate; and

,

j. inverting said homograft to position the surface of the collagenous homograft with the surface exposed to blood flow in said vessel to form an inside surface for the homograft and thereby provide a homograft having a surface compatible with blood flow.

2. A method of growing a homograft in accordance with claim 1 in which the tubular substrate is suspended in the blood flow for a time period not less than six weeks.

3. A method of growing a homograft in accordance with claim 1 in which said substrate is suspended in the blood flow for a period not to exceed eight weeks.

5. A method in accordance with claim 1 in which said anchor is a flexible tether connected to said first end of said substrate through a wall of said vessel, said flexible tether permitting said substrate to move freely within the lumen of said vessel to promote collagenous tissue growth on said thrombogenic surface.

6. A method in accordance with claim 1 wherein said outside surface has a diameter no greater than two-thirds of the diameter of the lumen of said vessel.

7. A method in accordance with claim 1 in which said substrate is suspended in the blood flow of said vessel for about six to about eight weeks to promote of the growth of collagenous tissue of uniform thickness on said thrombogenic surface and with a surface of said collagenous tissue having a shiny texture and physical characteristic similar to a surface texture of said vessel.

10. A method in accordance with claim 1 in which said device has a total diameter of no more than two-thirds of the diameter of the lumen of said vessel.

4. A method of growing a homograft in accordance with claim 26 in which said substrate is suspended in the lumen of a vessel for a period of time of about six weeks to about eight weeks.

8. The method of growing a homograft in a vessel having a lumen of sufficient size to accommodate a foreign body and carrying blood flow in a living body which comprises the steps of:

(a) selecting a tubular substrate having at least thrombogenic surface, said substrate having a generally cylindrical shape with first and second open ends to permit blood flow within the tubular substrate,

(b) attaching an anchor means to said first end of said substrate,

(c) making an incision in said vessel,

(d) inserting said tubular substrate into said vessel,

(e) positioning said tubular substrate in said vessel to permit blood flow through said substrate from said first end to said second end,

(f) anchoring said first end to prevent said substrate from moving with the flow of blood in said vessel, said anchor leaving said second end free to move within said vessel,

(g) leaving said substrate suspended in the blood flow of said vessel for a sufficient time for collagenous tissue generated by said body to form on the thrombogenic surface and form a homograft,

(h) removing said substrate from said vessel, and then

(i) removing said homograft from said substrate.

9. The method of growing a homograft in a vessel having a lumen of sufficient size to accommodate a foreign body and carrying blood flow in a living body which comprises:

a. selecting a tubular substrate having a generally cylindrical outer surface and a generally cylindrical inside surface, said substrate having a first and a second open end to permit blood flow along said inside surface, at least one of said surfaces being non-thrombogenic;

b. connecting a first end of a thrombogenic mesh material to said first end, said mesh material being generally tubular in shape;

c. extending said mesh material along the outside of said non-thrombogenic surface;

d. connecting a second end of said mesh material to said second end of said substrate to form a prosthetic device for promoting growth of collagenous tissue in said mesh material;

e. attaching anchor means to said first end of said substrate;

f. making an incision in a vessel;

g. inserting said device into the lumen of said vessel by placing the second end into said incision ahead of first end and in the same direction as the blood flow in said vessel;

h. positioning said device in said vessel to permit blood flow through said device over said inside surface and over said outside surface to promote growth of collagenous tissue on said mesh material;

i. anchoring said first end of said device to prevent said device from moving with the flow of blood in said vessel, said anchor leaving said second end free to move within said vessel;

j. leaving said device suspended in the blood flow of said vessel for a sufficient time for collagenous tissue generated by said body to form on the thrombogenic mesh material and form a homograft of collagenous tissue;

k. removing said device from said vessel; and

then,

l. removing said homograft from said substrate.

11. The method of growing a homograft in a vessel having a lumen of sufficient size to accommodate a foreign body and carrying blood flow in a living body which comprises:

a. selecting a tubular substrate having a generally cylindrical outer surface and a generally cylindrical inside surface, said substrate having a first and a second open end to permit blood flow along said inside surface, at least one of said surfaces being non-thrombogenic;

b. connecting a first end of a thrombogenic mesh material to said first end, said mesh material being generally tubular in shape;

c. extending said mesh material along the inside of said non-thrombogenic surface;

d. connecting a second end of said mesh material to said second end of said substrate to form a prosthetic device for promoting growth of collagenous tissue in said mesh material;

e. attaching anchor means to said first end of said substrate;

f. making an incision in a vessel;

g. inserting said device into the lumen of said vessel by placing the second end into said incision ahead of first end and in the same direction as the blood flow in said vessel;

h. positioning said device in said vessel to permit blood flow through said device over said inside surface and over said outside surface to promote growth of collagenous tissue on said mesh material;

i. anchoring said first end of said device to prevent said device from moving with the flow of blood in said vessel, said anchor leaving said second end free to move within said vessel;

j. leaving said device suspended in the blood flow of said vessel for a sufficient time for collagenous tissue generated by said body to form on the thrombogenic mesh material and form a homograft of collagenous tissue;

k. removing said device from said vessel;

l. removing said homograft from said substrate; and

,

m. inverting said homograft.

12. The method of growing a homograft in a vessel having a lumen of sufficient size to accommodate a foreign body and carrying blood flow in a living body which comprises:

a. selecting a tubular substrate having a generally cylindrical outer surface and a generally cylindrical inside surface, said substrate having a first and a second open end to permit blood flow along said inside surface, at least one of said surfaces being non-thrombogenic;

b. connecting a first end of a thrombogenic mesh material to said first end, said mesh material being generally tubular in shape and having a diameter substantially the same as a diameter of the inside surface of said substrate;

c. stretching the mesh material in order to reduce the diameter of the tubular material to suspend the mesh material along the inside surface of said substrate without substantial contact with said inside surface;

d. extending said mesh material along the inside of said non-thrombogenic surface;

e. connecting a second end of said mesh material to said second end of said substrate to form a prosthetic device for promoting growth of collagenous tissue in said mesh material;

f. attaching anchor means to said first end of said substrate;

g. making an incision in a vessel;

inserting said device into the lumen of said vessel by placing the second end into said incision ahead of first end and in the same direction as the blood flow in said vessel;

i. positioning said device in said vessel to permit blood flow through said device over said inside surface ad over said outside surface to promote growth of collagenous tissue on said mesh material;

j. anchoring said first end of said device to prevent said device from moving with the flow of blood in said vessel, said anchor leaving said second end free to move within said vessel;

k. leaving said device suspended in the blood flow of said vessel for a sufficient time for collagenous tissue generated by said body to form on the thrombogenic mesh material and form a homograft of collagenous tissue;

l. removing said device from said vessel; and

,

m. removing said homograft from said substrate.

13. The method of growing a homograft in a vessel having a lumen of sufficient size to accommodate a foreign body and carrying blood flow in a living body which comprises:

a. selecting a tubular substrate having a generally cylindrical outer surface and a generally cylindrical inside surface, said substrate having a first and a second open end to permit blood flow along said inside surface, at least one of said surfaces being non-thrombogenic;

b. dissolving a portion of said substrate near each of said first and second open ends;

c. placing a first end of a thrombogenic mesh material in contact with said dissolved area of said first end for a sufficient period of time to permit the substrate to resolidify and anchor the mesh material at said first open end, said mesh material being generally tubular in shape;

d. extending said mesh material along said non-thrombogenic surface;

e. placing a second end of said mesh material to said dissolved area of said second end of said substrate for a sufficient period of time to permit the substrate to resolidify and anchor the mesh material at said second open end to form a prosthetic device for promoting growth of collagenous tissue in said mesh material;

f. attaching anchor means to said first end of said substrate;

g. making an incision in a vessel;

h. inserting said device into the lumen of said vessel by placing the second end into said incision ahead of first end and in the same direction as the blood flow in said vessel;

i. positioning said device in said vessel to permit blood flow through said device over said inside surface and over said outside surface to promote growth of collagenous tissue on said mesh material;

j. anchoring said first end of said device to prevent said device from moving with the flow of blood in said vessel, said anchor leaving said second end free to move within said vessel;

k. leaving aid device suspended in the blood flow of said vessel for a sufficient time for collagenous tissue generated by said body to form on the thrombogenic mesh material and for a homograft of collagenous tissue;

l. removing said device from said vessel; and

,

m. removing said homograft from said substrate.