Patent ID: 8361097

Claim:
A method of delivering a guidewire across an atherosclerotic occlusion or lesion in a vascular lumen while protecting the vascular lumen, said method comprising: passing a distal end of a catheter tube having a rotatable cutting head and a sheath through the vascular lumen to the occlusion or lesion, wherein the rotatable cutting head is retracted within the sheath during the passing step such that one or more helical cutting surfaces extending proximally along the rotatable cutting head are engaged with one or more helical slots extending laterally through a sidewall of the sheath; extending the rotatable cutting head from the sheath such that the one or more helical cutting surfaces extend at least partially out of the sheath; rotating the rotatable cutting head; advancing said rotating cutting head across said occlusion or lesion to pass through occluding material without removing the occluding material; and passing a guidewire through a guidewire passageway extending through the catheter tube after the distal end of the catheter tube has passed beyond the atherosclerotic occlusion so that the guidewire spans the atherosclerotic occlusion or lesion.