Stent
The present invention relates to an aneurysm stent for implantation into a living body, in particular for treatment of aneurysms, in order to implant the stent in the compressed state in a vessel and expand the stent after positioning it in the vessel, having a grid or mesh structure and at least one membrane ( 2 ) or a plurality of membranes ( 2 ) for covering at least one or more stent cells ( 1; 3 ) in the grid or mesh structure, thereby matching the permeation characteristics of the stent structure to the particular characteristics of the aneurysm.
1. An aneurysm stent for implantation into a living body for the treatment of aneurysms, the stent comprising:
a compressed state for positioning the stent in a vessel and an expanded state for treating the aneurysm, the aneurysm stent having a grid or mesh structure comprising non-covered stent cells and covered stent cells, wherein the stent cells are compressed when the stent is in the compressed state, wherein each covered stent cell contains a membrane, the membrane having a non-porous or closed structure to reduce fluid permeability in a region of the membrane, and wherein each entire membrane is provided in the corresponding covered stent cell within a thickness of that stent cell so that each membrane does not project beyond a thickness of the grid or mesh structure.
2. An aneurysm stent according to claim 1 , wherein the membrane is less thick than the web thickness of the corresponding covered stent cell.
3. An aneurysm stent according to claim 1 , wherein the membrane has essentially the same thickness as the web thickness of the corresponding covered stent cell.
4. An aneurysm stent according to claim 1 , wherein the membrane includes a polymer.
5. An aneurysm stent according to claim 1 , wherein the membrane is attached to webs of the corresponding covered stent cell by adhesion.
6. An aneurysm stent according to claim 1 , wherein the membrane includes an X-ray-visible material.
7. An aneurysm stent according to claim 1 , wherein the membrane is filled with a medication.
8. An aneurysm stent according to claim 1 , wherein a plurality of stent cells in a uniform row or in a uniform pattern is covered by the membrane.
9. An aneurysm stent according to claim 1 , wherein at least one covered stent cell is positioned adjacent to a non-covered stent cell.
10. An aneurysm stent according to claim 1 , wherein a plurality of the non-covered stent cells are interconnected.
11. An aneurysm stent according to claim 1 , wherein the stent structure has a tubular shape.
12. A method for producing an aneurysm stent, the method comprising:
preparing a stent structure from a material having shape memory characteristics with webs, the stent structure having first and second stent cells formed between the webs, the stent structure compressible into a compressed state in which the stent cells are compressed; and
in each of the first stent cells, attaching a membrane to the webs of the first stent cell such that the second stent cells are not covered by the membrane, each membrane having a non-porous or closed structure to reduce fluid permeability in a region of the membrane, and wherein each entire membrane is provided in the corresponding first stent cell within a web thickness of the corresponding first stent cell so that the membrane does not project beyond the stent structure.
13. A method according to claim 12 , wherein the membrane is attached to the webs by adhesion.
14. A method according to claim 12 , wherein the membrane is filled with a medication.
15. A method according to claim 12 , wherein the membrane is provided with an X-ray-visible material.
16. A method according to claim 12 , wherein the stent structure has a tubular shape.