US Patent 7846195 Stent graft tapered spring

A stent graft includes a stent graft material of cylindrical shape and tapered stent springs coupled to the stent graft material. Each stent spring includes a first stent cell and a second stent cell contiguous with the first stent cell. The first stent cell and the second stent cell are coupled. The second stent cell of each tapered stent spring is smaller than the first stent cell thereby defining a tapered shape to the tapered stent springs. The stent graft is placed in a curved segment of a tortuous body lumen and rotationally positioned such that the smallest stent cell of each tapered stent spring is placed at an inside radius of the curved segment.