Highly flexible stent and method of manufacture
Preferred embodiments of a stent with a high degree of flexibility are shown and described. The stent can include a continuous helical winding having interconnected struts joined at vertices, and having bridges connecting sections of the helical winding to each other. An annular ring can be provided at one or both ends of the helical winding, and the annular ring can have extensions extending to connect to the helical winding. One of the extensions can connect to a bridge and another extension can connect to a vertex. The struts at the ends of the helical winding can have strut lengths that differ from the strut lengths of the struts in a central portion of the winding between the ends of the winding.
1. An implantable prosthesis comprising:
a first pattern defining a continuous helical winding having a plurality of circumferential sections circumscribing a longitudinal axis from a first end to a second end, the circumferential sections including a first end circumferential section at the first end and a second end circumferential section at the second end and one or more central circumferential sections therebetween, the circumferential sections being spaced apart along the axis and including a plurality of struts joined together end-to-end, the end-to-end joining of two struts of the plurality of struts defining a vertex between the two struts, at least one of the vertices of the first or second end circumferential sections being an end vertex formed by a joining of two final struts of the first or second end circumferential sections, a plurality of bridges connecting one circumferential section to an adjacent circumferential section; and
a second pattern defining an annular ring having a plurality of extensions extending therefrom and connecting to the continuous helical winding, at least one extension connecting to the end vertex, at least one of the two final struts joining together to define the end vertex having an end strut length, the end strut length being different than a range of central strut lengths of the struts of the one or more central circumferential sections.
2. The implantable prosthesis according to claim 1 , wherein the first pattern comprises the plurality of bridges having a minimum width greater than a width of any of the plurality of struts.
3. The implantable prosthesis according to claim 1 , wherein the first pattern comprises defining the continuous helical winding as a single helical winding.
4. The implantable prosthesis according to claim 1 , wherein the first pattern comprises the plurality of bridges extending substantially parallel with respect to the longitudinal axis.
5. The implantable prosthesis according to claim 1 , wherein the first pattern comprises forming the plurality of bridges such that at least one of the bridges extends obliquely with respect to an axis extending parallel to the longitudinal axis.
6. The implantable prosthesis according to claim 1 , wherein the forming a first pattern comprises forming the plurality of bridges such that at least one of the bridges directly connects a peak of one circumferential section to another peak of an adjacent circumferential section.
7. The implantable prosthesis according to claim 1 , wherein the forming a first pattern comprises forming the plurality of bridges such that at least one of the bridges directly connects a peak of one circumferential section to a trough of an adjacent circumferential section.
8. The implantable prosthesis according to claim 1 , wherein the forming a first pattern comprises forming the plurality of bridges such that at least one of the bridges directly connects a trough of one circumferential section to a trough of an adjacent circumferential section.
9. The implantable prosthesis according to claim 1 , wherein the forming a first pattern comprises forming the plurality of struts to have a width of approximately 80% of a width of the plurality of bridges.