Medical catheter apparatus

A medical catheter apparatus comprising:

• a catheter including an outer periphery on which a cylindrical vascular stent is configured to be mounted and a distal portion comprising a balloon which is to be inflated with a supply of an expansion medium to expand the stent in diameter, being provided with at least an expansion medium supplying channel extending from the distal portion to a proximal portion for supplying the expansion medium to expand the balloon, and a guide wire insertion channel extending from the distal portion to a middle portion for inserting a guide wire, and
• a sheath into which the catheter is inserted, covering the outer peripherly of the catheter from a distal side of the catheter where the balloon attaching the vascular stent is positioned through a proximal side of the catheter, and moving relative to the catheter between the section where the sheath is covering the balloon attaching the vascular stent and the section where the sheath is supposed to expose the vascular stent attached to the balloon, wherein
• the catheter is provided at its middle portion with a guide wire leading-out opening for leading out the guide wire inserted from the distal portion of the catheter toward a side direction of the catheter,
• the sheath is provided at its middle portion with a guide wire drawing-out opening for drawing the guide wire drawn from the catheter out of the sheath,
• a guide wire drawing-out guiding mechanism comprising:
• a first tubular member, having a proximal end of which is connected with the guide wire leading-out opening formed on the catheter, extending along the outer surface of the catheter toward the guide wire drawing-out opening formed on the sheath, and
• a second tubular member, having a proximal end of which is connected with the guide wire drawing-out opening formed on the sheath, extending along the inner surface of the sheath toward the guide wire leading-out opening formed on the catheter,
• the first tubular member and the second tubular member being connected movably back and forth by slidably fitting their end sections together,
• wherein the guide wire drawing-out mechanism is provided between the guide wire leading-out opening and the guide wire drawing-out opening for connecting the guide wire leading-out opening and the guide wire drawing-out opening, and for guiding the guide wire led out from the guide wire leading-out opening to the guide wire drawing-out opening, and
• wherein the guide wire drawing-out guiding mechanism has a variable length from the guide wire leading-out opening to the guide wire drawing-out opening which varies in accordance with the relative movement of the sheath with respect to the catheter.