Expandable stent

Claim 1

A radially expandable stent for intravascular implantation that includes a plurality of helically aligned circumferential sections including two end sections and a plurality of intermediate sections that define a cylinder having a longitudinal axis, said cylinder formed of a continuous wire with said circumferential sections being spaced along said axis in abutting contact, each of said circumferential sections having expandable segments that impart radial expandability to said sections whereby said sections have an unexpanded insertion circumference and an expanded implantation circumference that is greater than said insertion circumference, said expandable segments being in their unexpanded mode, teardrop shaped elements that are alternately inverted about said circumferential sections, each element containing a base and a pair of legs that come together with a common apex when the stent is in a unexpanded condition, said expandable segments being in their expanded mode, U-shaped elements that are alternately inverted about said circumferential sections, one of said end sections having a free end that is passed back along the circumferential sections and is looped or wrapped around the circumferential sections at a plurality of preselected locations to provide dimensional stability and to prevent axial expansion of the stent during radial expansion.