The present invention provides a
stent delivery
catheter that can place a
stent in a tortuous narrowed area with good maneuverability while preventing falling or displacement of the
stent. The present invention provides a stent delivery
catheter for delivering a stent for treating
stenosis in a body to a narrowed area. A distal end of the
catheter includes a collapsible
balloon in a collapsed state and the stent in an undeployed state, the stent being mounted on the outer surface of the collapsed
balloon, the
balloon having frustoconical tapered segments and a cylindrical straight tubular segment. An inner tube for defining a guidewire lumen extends into the interior of the balloon, and displacement prevention mechanisms for preventing the stent from moving in the longitudinal direction of the stent delivery catheter are affixed to the inner surface of the balloon only. Another aspect of the present invention provides a stent delivery catheter that can prevent the stent from moving in the axis direction of the catheter without requiring additional components or additional steps that complicate the manufacturing process. In this catheter, the thickness T1 of a near-center portion of the distal-end tapered segment and the thickness T2 of a near-center portion of the straight tubular segment satisfy a predetermined relationship, and the thickness T3 of a near-center portion of the proximal-end tapered segment and the thickness T2 of the near-center portion of the straight tubular segment satisfy a predetermined relationship. In this manner, the distal-end and proximal-end tapered segments in the collapsed state prevent the movement of the stent. The present invention also provides a preferable RX
balloon catheter, i.e., a stent delivery catheter, having improved maneuverability and enhanced responsiveness for expansion and contraction of the balloon without complicating the manufacturing process or increasing the cost.