UROLOGICAL STENT AND DEPLOYMENT DEVICE THEREFOR

摘要

A stent adapted for placing in the urethra so as to retain the urethra's dia meter above a critical level is provided. The stent comp rises: a spiral band made of a two-way shape memory alloy having two memory states consisting of a first state in which said alloy is soft and substantially deformable and a second state in which said alloy has super el astic properties and is substantially non-deformable, th e alloy changes from the first state to the second state at a first transition tempe rature being above physiological body temperature and ch anges from the second to the first state at a second transition temperature being below physiological body temperature; in said second state co nsecutive windings of the band are adjacent one another so that they form together ess entially a continuous cylindrical tube of a diameter abo ve said critical level; in said first state said band forms a coiled structure havin g a maximal external diameter so as to allow deployment of stent within the urethra.