Intraluminar perforated radially expandable drug delivery prosthesis and a method for the production thereof

• US 20020007209A1
• Filed: 03/06/2001
• Published: 01/17/2002
• Est. Priority Date: 03/06/2000
• Status: Active Grant

• Current Assignee: Advanced Laser Applications Holding S.A.
• Original Assignee: Advanced Laser Applications Holding S.A.
• Inventors: Sohier, Jurgen, Van Der Leden, Natasja, Scheerder, Ivan De
• Granted Patent: US 7,135,039 B2
• Time in Patent Office: Days
• US Class Current: 623/1.15
• CPC Class Codes: A61F 2/915 with bands having a meander structure, adjacent bands being connected to each other
• CPC Class Codes: A61F 2002/91541 Adjacent bands are arranged out of phase
• CPC Class Codes: A61F 2002/91558 connected peak to peak
• CPC Class Codes: A61F 2230/0013 Horseshoe-shaped, e.g. crescent-shaped, C-shaped, U-shaped
• CPC Class Codes: A61F 2250/0067 Means for introducing or releasing pharmaceutical products into the body
• CPC Class Codes: A61F 2250/0068 the pharmaceutical product being in a reservoir
• CPC Class Codes: A61L 2300/00 Biologically active materials used in bandages, wound dressings, absorbent pads or medical devices
• CPC Class Codes: A61L 2400/18 Modification of implant surfaces in order to improve biocompatibility, cell growth, fixation of biomolecules, e.g. plasma treatment
• CPC Class Codes: A61L 31/022 Metals or alloys
• CPC Class Codes: A61L 31/088 Other specific inorganic materials not covered by A61L31/084 or A61L31/086
• CPC Class Codes: Y10T 29/49996 Successive distinct removal operations

Abstract

The radially expandable prosthesis for implantation in a lumen comprises a tubular wall produced from sheet metal and showing cuts enabling the prosthesis to expand. By using water guided laser cutting technology to make these cuts and/or specific electrochemical polishing technology a more biocompatible prosthesis is obtained, causing less thrombogenicity and less foreign body reaction. By covering an intraluminal prosthesis with a titaniumnitride coating the biocompatibility of the prosthesis is improved. By applying perforating or non-perforating holes (4) and filling these holes with a therapeutic agent, the intraluminal prosthesis can be used to locally administer medicines, genes and or other substances to prevent in this way thrombotic occlusions and/or neointimal hyperplasia and prosthesis narrowing. Using this specific perforated prosthesis design the total drug capacity can be increased and also the drug release time prolongs significantly.

Claims

1. A method for producing a radially expandable prosthesis for implantation in a lumen and comprising a tubular wall produced from sheet metal and showing cuts enabling the prosthesis to expand, in which method said cuts are at least partially made by means of a laser beam, for making at least a number of said cuts, said laser beam being guided in a jet of liquid towards this sheet metal.

2. The method as claimed in claim 1, wherein said liquid comprises water.

3. The method as claimed in claim 1, wherein said liquid is ejected out of a nozzle at a pressure, sufficient to remove metal particles burned by means of the laser beam from the sheet metal, said liquid being in particular ejected out of said nozzle at a pressure of between 20 and 500 bars, more particularly at a pressure of between 100 and 300 bars, and preferably at a pressure of about 150 bars.

4. The method as claimed in claim 1, wherein said liquid is ejected out of a nozzle opening having an inner diameter of 20 to 100 μ

m, in particular an inner diameter of 40 to 60 μ

m, and more particularly an inner diameter of about 60 μ

m.

5. A method, in particular the method as claimed in claim 1, for producing a radially expandable prosthesis for implantation in a lumen and comprising a tubular wall produced from sheet metal made from a nickel titanium alloy, in particular from nitinol, and showing cuts enabling the prosthesis to expand, in which method said cuts are at least partially made by means of a laser beam, and said prosthesis is polished electrochemically in an electrolyte solution containing perchloric acid and at least one carboxylic acid, in particular acetic acid.

6. The method as claimed in claim 5, wherein said electrolyte solution comprises said perchloric acid and said acetic acid in a concentration corresponding to the perchloric acid and acetic acid concentrations in a mixture of 1 to 10 volume parts of a 70% by weight perchloric acid solution and 2 to 500 volume parts of a 99.8% by weight acetic acid solution, and more particularly in a concentration corresponding to the perchloric acid and acetic acid concentrations in a mixture of about 5 to about 6 volume parts, preferably about 5 volume parts, of a 70% by weight perchloric acid solution and about 94 to about 100 volume parts, preferably about 100 volum2e parts, of a 99.8% by weight acetic acid solution.

7. The method as claimed in claim 5, wherein before electrochemically polishing the prosthesis, the prosthesis is pickled with an acid solution containing hydrofluoric acid and nitric acid, in particular in a concentration effective to remove oxides from the prosthesis.

8. A method, in particular the method as claimed in claim 1, for producing a radially expandable prosthesis for implantation in a lumen and comprising a tubular wall produced from sheet metal made from tantalum and showing cuts enabling the prosthesis to expand, in which method said cuts are at least partially made by means of a laser beam, and said prosthesis is polished electrochemically in an electrolyte solution containing sulfuric acid and hydrofluoric acid.

9. The method as claimed in claim 8, wherein said electrolyte solution comprises said sulfuric acid and said hydrofluoric acid in a concentration corresponding to the sulfuric acid and hydrofluoric acid concentrations in a mixture of 70 to 120 volume parts of a 95 to 97% by weight sulfuric acid solution and 5 to 20 volume parts of a 48 to 51% by weight hydrofluoric acid solution, and more particularly in a concentration corresponding to the sulfuric acid and hydrofluoric acid concentrations in a mixture of about 90 volume parts of a 95 to 97% by weight sulfuric acid solution and about 10 volume parts of a 48 to 51% by weight hydrofluoric acid solution.

10. The method as claimed in claim 8, wherein said electrolyte solution further contains at least one carboxylic acid, in particular acetic acid.

11. The method as claimed in claim 10, wherein said electrolyte solution comprises said sulfuric acid, said hydrofluoric acid and said acetic acid in a concentration corresponding to the sulfuric acid, hydrofluoric acid and acetic acid concentrations in a mixture of 20 to 80 volume parts of a 95 to 97% by weight sulfuric acid solution, 5 to 20 volume parts of a 48 to 51% by weight hydrofluoric acid solution and 10 to 30 volume parts of a 99.8% by weight acetic acid solution, and more particularly in a concentration corresponding to the sulfuric acid, hydrofluoric acid and acetic acid concentrations in a mixture of about 50 volume parts of a 95 to 97% by weight sulfuric acid solution, about 10 volume parts of a 48 to 51 % by weight hydrofluoric acid solution and about 20 volume parts of a 99.8% by weight acetic acid solution.

12. The method as claimed in claim 8, wherein before electrochemically polishing the prosthesis, the prosthesis is pickled with an acid solution containing hydrofluoric acid, sulfuric acid and nitric acid, in particular in a concentration effective to remove oxides from the prosthesis.

13. The method as claimed in claims 1, 5 or 8, wherein the prosthesis is covered with a titanium nitride coating showing a thickness of between 0.1 and 500 μ

m, and preferably a thickness of between 1 and 10 μ

m.

14. A radially expandable prosthesis for implantation in a lumen comprising a tubular wall produced from sheet metal and showing cuts enabling the prosthesis to expand, wherein the prosthesis is obtainable by applying the method as claimed in claim 1, 5 or 8.

15. The prosthesis as claimed in claim 14, wherein the sheet metal from which it is produced shows adjacent said cuts a metal grain structure obtainable by cutting said portions out by means of a laser beam guided in a jet of liquid, in particular by applying the method as claimed in claim 1.

16. A radially expandable prosthesis for implantation in a lumen, in particular a prosthesis as claimed in claim 14 or 15, comprising a tubular wall produced from sheet material, in particular from sheet metal, and showing an inner and an outer surface, which tubular wall is provided with cuts forming struts having a predetermined thickness and enabling the prosthesis to expand, said struts having a longitudinal direction and showing reservoirs made in said outer surface for containing a therapeutic agent, wherein at least a number of said reservoirs are formed by holes which show at least an outer opening at the outer surface of the tubular wall and which extend over a depth in said struts larger than 30%, preferably larger than 50% and most preferably larger than 60%, of the thickness thereof, said outer opening having a width measured perpendicular to said longitudinal direction and a length measured in said longitudinal direction which comprises at the most five times, preferably at the most three times, said width.

17. The prosthesis as claimed in claim 16, wherein said length is substantially equal to said width, said outer opening being in particular substantially circular.

18. The prosthesis as claimed in claim 16, wherein said width is larger than 10 μ

m, in particular larger than 20 μ

m and more particularly larger than 30 μ

m but smaller than 100 μ

m, preferably smaller than 60 μ

n and most preferably smaller or equal to 50 μ

m.

19. The prosthesis as claimed in claim 16, wherein the strut wherein said outer opening is situated has a strut width measured between a first longitudinal edge of the outer surface of the strut and a second longitudinal edge of this outer surface, the width of said outer opening comprising at the most 60%, preferably at the most 50%, of said strut width.

20. The prosthesis as claimed in claim 16, wherein said holes are divided according to the longitudinal directions of the struts on these struts, preferably on a substantially constant mutual distance.

21. The prosthesis as claimed in claim 16, wherein said hole has a bottom, at least a bottom portion of said hole being substantially conical.

22. The prosthesis as claimed in claims 16, wherein said hole extends through the strut forming in said inner surface of the tubular wall an inner opening.

23. The prosthesis as claimed in claim 22, wherein said inner opening is smaller than said outer opening, at least a bottom portion of said hole narrowing preferably conically towards said inner opening.

24. The prosthesis as claimed in claim 22, wherein said inner opening has substantially the same size as said outer opening.