Catheter with detached proximal inflation and guidewire shafts

A balloon catheter includes a full-length inflation shaft and a guidewire shaft for fast catheter and guidewire exchange. The proximal portions of the inflation shaft and the guidewire shaft are detached from one another. The detached proximal shaft portions transition within a conversion portion of the catheter shaft and become coaxial within a distal portion of the catheter shaft. The proximal portion of the guidewire shaft may contain a continuous, longitudinally extending slot that acts as a guide member or guidewire track. Alternatively, the proximal portion of the guidewire shaft maybe removable from the catheter at a conversion joint via a snap-fit connection. Both embodiments allow for catheter exchange without removing the guidewire from a body lumen, or allow guidewire exchange without removing the catheter from the body lumen.