Abstract: A dilatation catheter is provided with an inflatable section which in its non-inflated condition may have a diameter several times that of the balance of the catheter. Means are provided to axially twist the inflatable part of the catheter to reduce its diameter in its non-inflated condition to a size comparable to that of the non-inflatable balance of the catheter so that the catheter may be threaded through and positionally emplaced within a blood vessel.

Abstract: A center-pull cutting annulus which is radially expansible is employed to achieve complete removal of arteriosclerotic material from occluded arteries.

Abstract: A balloon catheter wherein the balloon is inverted within the distal end of the catheter for eversion therefrom and extrusion through a partially occluded blood vessel in response to the exertion of internal fluid pressure on the balloon. The catheter is designed to extrude through the occluded vessel in advance of substantial lateral expansion and, upon full extension, is adapted to expand to a condition at least partially dilating the occlusion. A cord connected to the balloon and extending through the catheter provides means whereby tension may be applied to the balloon to reinvert it within the catheter. A reservoir in communication with the inner lumen of the catheter provides a closed fluid-filled system whereby the balloon may be sequentially everted and reinverted without venting outside of the system.