Abstract: A side-cutting atherectomy catheter with a housing containing a tissue-removal means, a window on one side, and a large volume inflatable support on the opposite side. The large volume inflatable support has a maximum diameter larger than the diameter of the cutter housing, generating a greater degree of contact with a blood vessel's interior diameter than conventional balloon-housing configurations. This feature stabilizes the cutter housing and improves tissue-removal during the atherectomy procedure. Large volume inflatable supports have a maximum inflated diameter at least 1.1 times, and preferably 1.35 times, greater than the diameter of the housing. The supports may be formed from either elastic or inelastic materials. When formed from inelastic materials, the supports have slack material when uninflated which can extend into and become entangled with the cutter window. To prevent this problem, the large volume inflatable support is constrained when uninflated.

Abstract: An improved vascular dilation catheter comprises an involuted tubular structure including outer and inner tubular walls which extend the entire length of the catheter. The outer tubular wall is enlarged at a distal end of the catheter to form a dilation balloon, and extends back the remaining length of the flexible tube at a reduced diameter to define an annular lumen which is used to inflate the balloon. Alternatively, the outer tubular wall may conform to the exterior of the inner tubular wall and separate axial lumens may be provided for inflation. By providing means for heating inflation medium within the balloon, the catheter may be utilized for performing thermal ablation therapy.