Foam-type vascular prosthesis with well-defined angio-permissive open porosity
AssigneeMedtronic, Inc.
InventorsPeter Paul Zilla, Deon Bezuidenhout
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Abstract
A vascular prosthesis is constructed from a well-defined pore structure to allow uninterrupted ingrowth of connective tissue into a wall of the prosthesis. Several different methods can be used to produce the prosthesis, including a vacuum impregnation technique, a paste molding technique, a paste extrusion technique, a dip coating technique, and a melt extrusion technique. Furthermore, mechanical properties of the prosthesis are matched with mechanical properties of the host vessel, thereby overcoming problems of compliance mismatch.
Claims112
A vascular graft prosthesis comprising:
- a polymeric tubular structure having a wall;
- and
- interconnecting, uniformly shaped pores in the tube wall;
- wherein at least 75% of the pores have diameters within 20 μm of one another.
A vascular graft prosthesis comprising:
- an elastomeric polymeric tubular structure having a wall;
- and
- interconnecting, uniformly shaped pores in the tube wall;
- wherein at least 75% of the pores have volumes within 4.2×10−6 mm3 of one another.
A prosthetic heart valve comprising:
- an elastomeric polymeric tubular structure having a wall;
- and
- interconnecting, uniformly shaped pores in the tube wall;
- wherein at least 75% of the pores have diameters within 20 μm of one another.
A sewing ring comprising:
- an elastomeric polymeric tubular structure having a wall;
- and
- interconnecting, uniformly shaped pores in the tube wall;
- wherein at least 75% of the pores have diameters within 20 μm of one another.
A stent comprising:
- an elastomeric polymeric tubular structure having a wall;
- and
- interconnecting, uniformly shaped pores in the tube wall;
- wherein at least 75% of the pores have diameters within 20 μm of one another.
A method of making a prosthesis comprising the steps of:
- providing at least one cylindrical mold in a casting device, with a central rod centrally positioned within the mold;
- filling an annulus of the at least one mold with extractable filler particles;
- injecting a graft material solution into the annulus, such that the graft material solution permeates spaces between the filler particles in the at least one mold;
- precipitating graft material from the graft material solution;
- removing the central rod from the at least one mold;
- removing the graft material from the at least one mold;
- and
- extracting the filler particles from the graft material.
A method of making a prosthesis comprising the steps of:
- preparing a paste comprising an extractable filler and a graft material solution;
- rolling a desired thickness of the paste onto a mandrel, wherein the mandrel has an outside diameter about equal to a desired inside diameter of the vascular graft prosthesis;
- precipitating graft material from the graft material solution;
- and
- extracting the filler from the graft material.
A method of making a prosthesis comprising the steps of:
- preparing a paste comprising an extractable filler and a graft material solution;
- extruding the paste through an annular orifice;
- precipitating graft material from the graft material solution;
- and
- extracting the filler from the graft material.
A method of making a prosthesis comprising the steps of:
- Preparing a paste comprising an extractable filler and a graft material solution;
- Depositing the paste in consecutive layers onto a mandrel, wherein the mandrel has an outside diameter about equal to a desired inside diameter of the vascular graft prosthesis;
- Precipitating graft material from the graft material solution;
- and
- Extracting the filler from the graft material.
A method of making a prosthesis comprising the steps of:
- extruding a thermoplastic elastomer with the aid of a blowing agent, to produce a foamed graft;
- and
- annealing and reticulating the foamed graft to effect an open-cell structure.
Dependencies are inferred from the claim text.