Low profile catheter for increasing lumen size of a blood vessel and guide wire therefor

A low profile catheter comprising:

• a catheter shaft having proximal and distal ends and defining an axis extending therebetween;
• a sleeve carried by the catheter shaft and having an internal opening which is other than round, said sleeve operative to receive a guide wire axially moveable in the sleeve and to transmit torque therebetween.

An intravascular guide wire comprising:

• a wire body having a proximal end and a distal end;
• a flexible end portion carried by the wire body at the distal end;
• said wire body having at least a portion thereof with an other than round profile.

A low profile catheter for intravascular use comprising:

• a catheter shaft having proximal and distal ends and defining an axis extending therebetween;
• a first coil spring carried by the catheter shaft and positioned to surround the guide wire, said first coil spring operative to seize the guide wire for rotation with the catheter shaft when the catheter shaft is rotated in a first direction with respect to the guide wire, and to release the guide wire for longitudinal movement with respect to the catheter shaft when the catheter shaft is not rotated in the first direction with respect to the guide wire.