Patent ID: 6190393
Filing Date: 2001-02-20
Classification: A61F

Abstract:
A stent deployment system, comprising:a balloon catheter with an elongated flexible shaft having proximal and distal ends, a hub affixed to the shaft proximal end having a hub inflation port, and an inflatable balloon affixed to the shaft near the shaft distal end;wherein the shaft defines an inflation lumen providing fluid communication of an inflation fluid between the hub inflation port and the balloon; at least a distal portion of the shaft having an inner member surrounded by an outer tube, at least a portion of the inflation lumen being defined by an annular space between the inner member and outer tube;such that the balloon is adapted for selective inflation from a deflated state to an inflated state, as well as later deflation; the balloon being formed of a substantially inelastic material; the balloon having an inflated state with a cylindrical working portion located between a pair of proximal and distal conical portions, and a pair of proximal and distal leg portions; the proximal leg of the balloon being affixed to the outer tube, and the distal leg of the balloon being affixed to the inner member;an expandable tubular stent mounted around the balloon and being crimped in an initial state about an outer surface of the deflated balloon;a flexible introducer tip affixed to a distal end of the inner member, the introducer tip defining a relatively long conical surface tapering from a distal profile equal to or less than the inner member distal tip, up to a maximum profile, the introducer tip further defining a shoulder and collar; anda tubular sheath surrounding at least a portion of the balloon catheter outer tube, wherein the stent defines a crimped outer diameter in an initial state, the sheath having a proximal hub and a tubular sheath member, the tubular sheath member having a distal sheath portion with an inner diameter greater than the crimped outer diameter of the stent and being adapted to cover the stent in its initial state and an outer sheath diameter equal to the maximum profile, and a proximal sheath portion having a diameter less than said distal sheath portion, the sheath being partially retractable in a proximal direction to uncover the stent and enable the balloon to be inflated to expand the stent;wherein a distal end of the tubular sheath member fits over the collar of the introducer tip, and is adapted to push on the shoulder of the introducer tip in a distal direction to enhance the pushability characteristic of the stent delivery system such that the stent delivery system achieves a primary stenting capability.