Endoluminal implantable stent-grafts
View Patent ↗An implantable endoluminal device that is fabricated from materials that present a blood or body fluid and tissue contact surface that has controlled heterogeneities in material constitution. An endoluminal stent-graft and web-stent that is made of an monolithic material deposited into a monolayer and etched into regions of structural members and web regions subtending interstitial regions between the structural members. An endoluminal graft is also provided which is made of a biocompatible metal or metal-like material. The endoluminal stent-graft is characterized by having controlled heterogeneities in the stent material along the blood flow surface of the stent and the method of fabricating the stent using vacuum deposition methods.
1. An implantable medical device, comprising a stent and a stent cover, wherein the stent comprises at least one of a plurality of structural members, and the stent cover comprises a continuous thin film web contiguous with and extending from the at least one of a plurality of structural members of the stent; wherein the web and the stent are formed of a biocompatible metallic material.
2. The implantable medical device according to claim 1 , wherein the metallic material of the stent and the stent cover is selected from the group consisting of titanium, vanadium, aluminum, nickel, tantalum, zirconium, chromium, silver, gold, silicon, magnesium, niobium, scandium, platinum, cobalt, palladium, manganese, molybdenum and alloys thereof, and nitinol and stainless steel.
3. The implantable medical device according to claim 2 , wherein the structural members and the web further comprise controlled heterogeneities on a luminal surface thereof, the controlled heterogeneities being selected from the group consisting of grain size, grain phase, grain material composition, material composition and surface topography.
4. The implantable medical device according to claim 3 , wherein the controlled heterogeneities define polar and non-polar binding sites for binding blood plasma proteins.
5. The implantable medical device according to claim 3 , wherein the controlled heterogeneities are dimensioned to have a blood contact surface area substantially similar in size as endothelial cell surface integrin clusters.
6. The implantable medical device according to claim 3 , wherein the controlled heterogeneities define cell-adhesion domains having interdomain boundaries less than the surface area of a human endothelial cell.
7. The implantable medical device according to claim 3 , wherein the controlled heterogeneities are dimensioned to have a blood contact surface area of about less than 6 μm 2 .
8. The implantable medical device according to claim 3 , wherein the controlled heterogeneity is selected from the group consisting of grain size, grain phase and grain composition.
9. The implantable medical device according to claim 3 , wherein the controlled heterogeneity is material composition.
10. The implantable medical device according to claim 3 , wherein the controlled heterogeneity is luminal surface topography.
11. The implantable medical device according to claim 3 , wherein the controlled heterogeneity has a blood contact surface less than or equal to about 10 μm and an inter-heterogeneity boundary between about 0 and 2 μm.
12. The implantable medical device according to claim 3 , wherein the web is substantially co-planar with a luminal surface of the plurality of structural members.
13. The implantable medical device according to claim 2 , wherein the web is substantially co-planar with an abluminal surface of the plurality of structural members.
14. The implantable medical device according to claim 2 , wherein the web is intermediately positioned between the luminal and abluminal surfaces of the plurality of structural members and has a thickness less than tat of the plurality of structural members.
15. An endoluminal web-stent, comprising a generally tubular stent member comprised of a plurality of structural members separated by a plurality of interstitial regions, and a metal stent cover member subtending at least some of the plurality of interstitial regions, said metal stent cover member further comprising a continuous metal thin film fixed to at least one of the plurality of structural members and having a plurality of openings passing through the metal thin film and positioned in communication with the plurality of interstitial regions of the tubular stent member, the plurality of openings in the continuous metal thin film being smaller than the interstitial region of the tubular stent member adjacent the openings in the metal thin film.
16. The endoluminal web-stent according to claim 15 , wherein the materials of the stent member and the material of the stent cover member are selected from the group consisting of titanium, vanadium, aluminum, nickel, tantalum, zirconium, chromium, silver, gold, silicon, magnesium, niobium, scandium, platinum, cobalt, palladium, manganese, molybdenum and alloys thereof and nitinol and stainless steel.
17. The endoluminal web-stent according to claim 15 , wherein the stent cover member further comprises a metal thin film having a plurality of micro-openings passing through a thickness thereof.
18. An implantable medical device, comprising a metallic stent and a metallic stent cover, wherein the metallic stent comprises a plurality of structural members defining interstitial spaces between adjacent pairs of structural members and the metallic stent cover comprises a continuous tubular metal film that covers at least some of the plurality of structural members, is fixed to at least one of the plurality of structural members and has a plurality of openings passing through the metal thin film smaller than and adjacent to the interstitial spaces.
19. The implantable medical device according to claim 18 , wherein the plurality of structural members and the metallic stent cover comprise materials selected from the group consisting of titanium, vanadium, aluminum, nickel, tantalum, zirconium, chromium, silver, gold, silicon, magnesium, niobium, scandium, platinum, cobalt, palladium, manganese, molybdenum and alloys thereof, nitinol and stainless steel.
20. The implantable medical device according to claim 19 , wherein the metallic stent cover member further comprises a plurality of micro-openings passing through a thickness thereof.