Implants having high fatigue resistance, implant delivery systems, and methods of use
According to one aspect of the present invention, a fatigue resistant stent includes a flexible tubular structure having an inside diameter, an outside diameter, and a sidewall therebetween and having apertures extending through the sidewall. According to other aspects of the invention, processes for making a fatigue resistant stent are disclosed. According to further aspects of the invention, delivery systems for a fatigue resistant stent and methods of use are provided.
1. A stent, which comprises:
a stent structure including a sidewall defining a central longitudinal axis, the sidewall including a plurality of struts extending in at least a longitudinal direction and defining a plurality of undulating rows in a circumferential direction of the stent, adjacent undulating rows being connected to define a plurality of cells, each cell comprising a first group of struts having a first length and a first width, and a second group of struts having a second length and a second width, wherein the first length is different than the second length and the first width is different than the second width, each cell defining multiple apices facing a common direction, wherein the apices of each cell that are adjacent in the circumferential direction and that face the common direction are each offset with respect to one another in the longitudinal direction when the stent structure is in an unexpanded configuration; wherein adjacent cells are joined together in a circumferential direction by connecting a first strut of said first group of struts to a last strut of said second group of struts, as viewed in said circumferential direction.
2. The stent of claim 1 , wherein at least some of the apices are longitudinally opposed to one another when the stent is in an unexpanded configuration and are circumferentially offset from one another when said stent is in an expanded configuration.
3. The stent of claim 1 , wherein said stent structure comprises a laser cut tube.
4. The stent of claim 1 , wherein said stent structure comprises a wire joined at regions to form said struts and said apices.
5. The stent of claim 1 , wherein said stent structure comprises a braid.
6. The stent of claim 1 , wherein said first group of struts comprises three struts and said second group of struts comprises five struts.
7. The stent of claim 1 , wherein said apices of said first group of struts have a different width than said apices of said second group of struts.
8. The stent of claim 1 , wherein said struts in said first group have a smaller width and a smaller length than said struts in said second group.
9. The stent of claim 1 , wherein said struts in said first group have a greater width and a greater length than said struts in said second group.
10. The stent of claim 1 , wherein at least some longitudinally opposed apices are connected at first and second circumferential locations to define a plurality of closed cells.
11. The stent of claim 10 , wherein at least some of the closed cells include serpentine strut patterns which constitute reverse mirror images as to right and left sides of each closed cell.
12. The stent of claim 1 , wherein the at least some longitudinally opposed apices are connected by connectors at first and second circumferential locations.