EFFECTS OF ULTRASOUND ENERGY ON TOTAL PERIPHERAL ARTERY OCCLUSIONS - INITIAL ANGIOGRAPHIC AND ANGIOSCOPIC RESULTS

Ultrasonic energy has been shown to ablate atherosclerotic plaques and arterial and venous thrombi. We used an ultrasonic angioplasty device developed by our group in ten patients with totally occluded femoral artery during surgical bypass. Ultrasonic angioplasty was performed wi th a 130-cm long and 0.8-cm diameter titanium probe with a 2- or 2.5-m m titanium ball-tip. In one patient, angioplasty could not be performe d. Angiographic and angioscopic examination were performed before and after angioplasty in nine patients. Before ultrasound recanalization, angioscopic examination showed that the proximal end of the occlusion was formed by atheromatous material in 3 cases, red thrombus in 3 case s, and white thrombus in 3 cases. After ultrasound recanalization, ang ioscopy showed residual stenosis at the site of entry in only one case . In three other cases, the artery was free of residual stenosis witho ut persistent clot. In the five other patients, a residual stenosis wa s present beyond the proximal occlusion point with some fibrin mesh an d small clots. At angiography, flow was restored in 4 cases; in 4 pati ents flow rate of entry was slow in the distal segment; and in 1 patie nt, the distal arterial bed could not be opacified. Altogether, ultras onic angioplasty was able to recanalize a complete occlusion in nine o ut of ten patients, with partial or complete dissolution of clots and with no complication. At its present stage of development, adjunctive balloon angioplasty would be needed in most cases to obtain unrestrict ed flow and unsignificant residual stenosis. The limited maneuverabili ty of the probe and the relatively small size of the ball-tip may expl ain that all clots could not be treated. When those limitations are ov ercome, ultrasonic angioplasty could become very useful because of the combination of its mechanical effects and thrombus dissolution capabi lities.