Stents are typically designed with a generally symmetrical structure to allow the stent to be placed in any circumferential orientation without affecting stent design properties. However, some vessels are generally curved. As a result, implantation of a stent within a generally curved vessel results in loading along a particular direction. Conventional stents that are designed to be placed in any circumferential orientation are generally less capable of incurring loading in a particular direction.
Moreover, some vessels with a general curvature have a tendency to undergo severe bending such that their angle of curvature may continuously change. The portion of the suprafemoral artery (SFA) overlying the knee is an example of a curved vessel which undergoes significant changes in its angle of curvature due to bending of the knee. Stents that are typically straight when deployed will be subject to fatigue from the continuous changes in curvature of the SFA and may ultimately fail. Consequently, a curved stent that can accommodate such continuous bending and therefore adapt to various angles of curvatures within the artery is desirable.
When conventional stents which are straight along their length are deployed within a vessel they exert a continuous radial force on the vessel and attempt to straighten the lumen's original curvature. Therefore, in some cases, it may be desirable to deploy a stent that more closely corresponds to the original curvature of the lumen to avoid trauma and stresses upon the lumen.
In view of the drawbacks of current technology, there is a desire for a stent that can withstand asymmetrical loads incurred from conforming to the curvature of a curved vessel that may bend. Although the inventions described below may be useful in withstanding asymmetrical loads incurred from conforming to the curvature of a curved vessel that may bend, the claimed inventions may also solve other problems.
USPTO Backgrounds
USPTO Backgrounds