Patent ID: 7572270

Claim:
A balloon catheter stent deployment system, comprising: a balloon catheter with a flexible shaft having proximal and distal ends, a hub affixed to the shaft proximal end having an inflation port, and an inflatable balloon affixed to the shaft near the shaft distal end; the shaft defining an inflation lumen providing fluid communication of an inflation fluid between the hub inflation port and the balloon; such that the balloon is adapted for selective inflation from a deflated state to an inflated state, as well as later deflation; the balloon in the inflated state having a cylindrical working portion located between a pair of conical portions and a pair of leg portions affixed to the shaft; the balloon being initially in the deflated state having multiple longitudinal pleats wrapped around a portion of the shaft; an expandable tubular mesh stent defining a tubular wall thickness, mounted around the balloon and being crimped in an initial state to an initial crimped outer diameter; the stent in the initial state having a relaxed configuration with substantially no tendency to self-expand absent an expansive force caused by inflating the balloon; wherein the balloon in its deflated state defines a series of ridges in a region of the balloon underneath the crimped stent, and defines a first and second balloon shoulder located immediately proximal and distal of the stent and a balloon bed portion defined between the balloon shoulders, wherein the ridges each extend around the entire circumference of the deflated balloon; each ridge having a constant wall thickness with a convex outer surface and a concave inner surface; thereby tending to fictionally retain the stent in an initial longitudinal position while the catheter system is advanced or withdrawn along a vascular path and; wherein the balloon is adapted to inflate and expand the stent to a larger deployed stent diameter, whereby the balloon assumes substantially the inflated state with said cylindrical working portion above a transition pressure; such that the ridges are substantially not present in the inflated state; whereby the stent delivery system tends to retain the stent in an initial longitudinal position while the catheter system is advanced or withdrawn along a vascular path.