Abstract: A method of treating an injured blood vessel of a patient may first involve inflating a balloon of an access wire balloon catheter within the injured blood vessel to reduce blood flow past an injury site in the vessel. After inflation, the method may involve attaching an extension wire to an extra-corporeal end of the access wire balloon catheter that resides outside the patient. When the extension wire is attached, an inflation port of the access wire device is disposed outside the patient and between a free end of the extension wire and the balloon of the access wire balloon catheter. The method may further include advancing at least a first treatment catheter into the blood vessel over the access wire balloon catheter and at least a portion of the extension wire and treating the injured blood vessel using the first treatment catheter.