Abstract: The catheter of the invention generally has component parts made of polymeric materials and a fusion bond between these catheter parts containing a compatibilizing material which enhances the miscibility of the polymeric materials to facilitate the formation of the fusion bond. The catheter parts formed of polymeric materials may not be sufficiently miscible to readily form a fusion bond. The compatibilizing material increases the miscibility of the catheter parts in the molten state to effect the fusion bond between the polymeric materials. Chemical primer and plasma surface treatments may be used to provide the catheter parts to be bonded with functional groups which improve miscibility with the compatibilizing material.

Abstract: A polymeric heat shrinkable tubular sheath for mounting about a balloon on a dilatation catheter by heat treating at a temperature which does not detrimentally effect the properties of the balloon to shrink the sheath onto the balloon. The tubular sheath is preferably heated to a temperature above body temperature, e.g. 40<100.degree. C., preferably less than 85.degree. C., to heat shrink the sheath onto the balloon. A presently preferred polymeric material is a copolymer of ethylene(75%) and methyl acrylate (25%). The heat shrinkable sheath has an inner lumen with minimum dimensions large enough to facilitate the advancement of the sheath over the exterior of a dilatation balloon without the need for a great deal of manual manipulation by the physician or other operator prior to heat shrinking.

Abstract: A polymeric heat shrinkable tubular sheath for mounting about a balloon on a dilatation catheter by heat treating at a temperature which does not detrimentally effect the properties of the balloon to shrink the sheath onto the balloon. The tubular sheath is preferably heated to a temperature above body temperature, e.g. 40.degree.<100.degree. C., preferably less than 85.degree. C., to heat shrink the sheath onto the balloon. A presently preferred polymeric material is a copolymer of ethylene(75%) and methyl acrylate (25%). The heat shrinkable sheath has an inner lumen with minimum dimensions large enough to facilitate the advancement of the sheath over the exterior of a dilatation balloon without the need for a great deal of manual manipulation by the physician or other operator prior to heat shrinking.