A catheter having an elongated shaft with an inflation lumen and a guidewire lumen, a balloon on a distal shaft section, and a proximal intermediate port proximal to the balloon and a distal intermediate port distal to the balloon, the intermediate ports being in communication with the guidewire lumen...http://www.google.com.au/patents/US7300415?utm_source=gb-gplus-sharePatent US7300415 - Balloon catheter having an external guidewire
