Stent and method and device for fabricating the stent
Stent, as well as a method and device for fabricating the stent, wherein the stent has a tubular lattice structure comprising individual struts and at least one strut of which at least one longitudinal section runs with at least one directional component in the radial circumferential direction of the stent, wherein the surface of the longitudinal section facing the outside of the stent is curved only about the longitudinal axis of the stent. According to the invention, the surface of longitudinal section of the strut, which surface faces the inside of the stent, has such a curvature that the strut cross section is fluidically optimized.
1. A method of fabricating a stent, wherein the stent comprising a tube-like lattice structure comprising individual struts, wherein the stent has at least one strut from which at least one longitudinal section runs at least one directional component in the circumferential direction of the stent, wherein the surface of the longitudinal section facing the outside of the stent is curved only about the longitudinal axis of the stent, wherein the lattice structure of the stent is produced such that at least one longitudinal section of a strut running with at least one directional component in the radial circumferential direction of the stent has an essentially angular cross section, characterized in that a rounding of the luminal edges of the longitudinal section of the strut, and of said edges running with at least one directional component perpendicular to the longitudinal direction of the stent, is effected by at least one particle beam directed at the edges.
2. The method of fabricating a stent according to claim 1 , wherein the two luminal edges of the longitudinal section of the stent are each treated by at least one particle beam, wherein the directions of the two particle beams oppose each other.
3. The method of fabricating a stent according to claim 2 , wherein the particle beam from a nozzle inserted into the stent is targeted at the edges of the strut facing the nozzle, and the nozzle is withdrawn at a predetermined speed from the stent so as to effect sequential irradiation of multiple struts disposed side by side in the longitudinal direction for the stent.
4. The method of fabricating a stent according to claim 2 , wherein the irradiation of the edges is effected bilaterally, and wherein the nozzle is drawn at least once from the stent towards the first stent end and at least once from the stent towards the second stent end.
5. The method of fabricating a stent according to claim 2 , wherein after particle beam irradiation the stent is treated by means of electropolishing.
6. The method of fabricating a stent according to claim 3 , wherein the withdrawal speed of the nozzle is varied.
7. The method of fabricating a stent according to claim 1 , wherein at least two struts positioned at opposing end regions of the stent are each rounded on the luminal side to form an asymmetric convex shape such that opposing ends of the stent have mirror symmetry thereby providing a stent with a fluidically optimized proximal end that is independent of orientation when implanted.
8. The method of claim 1 , wherein the two struts are separated by at least one innermost strut lacking a rounded shape, wherein each end region extends over 20-30% of the length of the stent, starting from each stent end.
9. The method of fabricating a stent according to claim 8 , wherein the innermost strut is of a greater thickness than the at least two struts positioned at the opposing end regions.