Patent ID: 8043279

Claim:
A catheter comprising: a proximal shaft; an intermediate member connected to a front side of said proximal shaft; a distal shaft connected to a front portion of said intermediate member; a hub provided to a rear side of said proximal shaft; a balloon connected at a front portion of said distal shaft; an inner tube shaft coaxially extends through said distal shaft and said balloon and connected to a distal end of said balloon; a balloon lumen for communicating said hub to the inside of said balloon; and a guide wire lumen for allowing a guide wire to be inserted through said guide wire lumen, said guide wire lumen including a distal side aperture positioned on the distal side from a front end of said balloon and a proximal side aperture formed in a side surface of said intermediate member; a front portion of said distal shaft is configured as a grooved portion having a groove, the front portion of said distal shaft having the groove being positioned on a rear side of said balloon; a rear portion of said distal shaft is free of grooves; wherein said grooved portion is provided at a portion adjacent to said balloon and extends toward a proximal side of said distal shaft; said groove possessing a depth which changes relative to a longitudinal extent of the distal shaft so as to be relatively larger on a distal side of said grooved portion and relatively smaller on a proximal side of said grooved portion; and said proximal shaft includes a main shaft portion and a proximal shaft insertion portion formed by spiral slit on a front portion of said proximal shaft and inserted into a rear portion of said intermediate member, and a pitch of said spiral slit becomes gradually shorter toward a distal end of said spiral slit.