Abstract: A stent structure (30) particularly for use in treating cerebral aneurysms is provided with a fibrous coating (34) which reduces the permeability of the underlying stent (32) to an extent that the flow through the stent structure is sufficiently suppressed to allow for resorbtion of an aneurysm while still providing sufficient flow through the stent structure to allow for flow into the perforator vessels. The fibrous coating may have different permeabilities in different zones of the underlying stent (32). The coating could be applied to other devices such as filters and occluders.

Abstract: A stent (10) formed from cannula and having flexible segments (11) and high hoop strength segments (12) alternating therealong. Axial tie bars (21,22) interconnect the segments; minimal length reduction would occur upon expansion. In the high hoop strength segment (12), struts (16) are initially parallel in the unexpanded strut condition, while in the flexible segment (11), struts (14) extend from a respective bight (15) to converge at distal ends when unexpanded. In one embodiment, certain adjacent struts (16) of the hoop segment are spaced apart by a large gap (20) while others are spaced apart by a small gap (18). In another embodiment all the struts (16) of the hoop segment are spaced apart uniformly from each other (or from an axial tie bar) by a small gap (23), resulting in minimizing the occurrence of fatigue of high-stress sites upon expansion/contraction cycles from continuous pulsatile events.