The present invention provides an apparatus for performing angioplasty or vascular intervention procedures. The apparatus of the present invention comprises a catheter apparatus comprised of a superelastic hollow guidewire, a balloon member and a flexible tip. The superelastic hollow guidewire of the invention is preferably a hypotube of nitinol alloy. The use of nitinol alloy as hollow guidewire provides a catheter apparatus having high flexibility and torqueability as well as small cross sectional diameter.