In one preferred embodiment (as FIG. 26B shows), a razor blade or other cutting instrument can be used to split approximately 5 mm of the distal end of the outer catheter body 250, creating a pair of slots 360, as best shown by ???A??? in FIG. 26B. The proximal end of the balloon 300 can then be slid over the distal end of the outer catheter body 250, with the outer wall 310 positioned around the