US Patent 7169187 Biodegradable stent

The present invention is directed to stents that are formed into a helical structure having a plurality of coils, a longitudinal axis, an internal longitudinal passage, a distal section and a proximal section having different diameters; where the structure is made from a fiber having a cross-section and including an inner core having an exterior surface made from a biodegradable polymer having a first degradation rate and an outer section made from a blend of a first biodegradable polymer component and a second biodegradable polymer component covering the exterior surface of the inner core and having a second degradation rate; where the second degradation rate is lower than the first degradation rate.