Abstract: Catheters having three lumens for injection and removal of fluids comprise an elongated tube having an integrally formed septum which extends throughout the length of the tube and defines the three lumens which may have the same or different cross-sectional areas. A smooth conical tapered tip is provided at the distal end of the tube and one of the lumens extends continuously through the tip to an opening at the apex of the tip. The other lumens extend continuously from the proximal end of the tube to openings in their sidewalls at a location axially spaced from the tip at the distal end. These catheters permit higher rates of fluid transfer in dialysis and like procedures than do double lumen catheters and are less prone to occlusion.

Abstract: Angioplasty and related medical dilatation balloons are molded from a polyurethane in which the "soft" segment is a minor segment by weight and the "hard" segment is the major segment by weight and which polyurethane has a hardness of at least 75D and a glass transition temperature of more than about 38.degree. C. The balloons can be integrally molded on one end of a catheter fabricated from the above type of polyurethane. Alternatively, the balloon is formed from polyurethane of the above type and the catheter is formed from elastomeric polyurethane and like polymers commonly employed in preparation of catheters. The balloon is then bonded to the catheter by conventional procedures.