Abstract: An angioplasty catheter having an outer tubular member and a coaxially aligned inner tubular member. The outer tube is of a first predetermined diameter over a majority of its length, but then tapers down, in a transition zone, to a second predetermined diameter less than the first and which extends to the catheter's distal tip. The inner tube has a distal end shaped to mate with the inside surface of the outer tube in the transition zone to form a seal when the inner tube is advanced in the distal direction. An expander is secured to the outer tube and inflatable by perfusing a fluid in the zone between the outer and inner tubes and through ports formed through the wall of the outer tube in the transition zone. By manipulating the proximal end of the inner tube, blood or other fluids may be perfused or exasperated and made to inflate or deflate the expander, the distal end of the inner tube acting as a valve, seating with the inner surface of the outer tube in the transition zone.

Abstract: A tubular angiographic catheter containing a wrapped multi-apertured film embedded in the walls thereof. The film material and aperture size, shape and pattern may be varied to produce a tailored torque transfer characteristic for enhancing the maneuverability of the distal end of the catheter by manipulating its proximal end.