[Therapeutic ultrasound for the recanalization of peripheral vascular occlusions]

Since the development of percutaneous transluminal angioplasty several techniques such as laser or atherectomy devices have been developed for recanalization of peripheral arterial occlusions. In a first clinical study we investigated if also the application of intravascular ultrasound can be useful for recanalization of occluded peripheral arteries. We applied an ultrasound angioplasty device (ACOLYSIS, ANGIOSONICS, USA) in a percutaneous approach in 8 patients with peripheral arterial occlusions (7 femoro-popliteal segments, 1 external iliac artery-occlusion). All patients suffered from severe leg ischemia due to subacute thrombotic occlusions. The ultrasound transmitter was introduced and advanced under fluoroscopic guidance to the site of the lesion. After activation the ultrasound transmitter was slowly advanced into the occlusion easily creating a channel within the occlusive material. Depending on the length of the occlusion (5-16 cm) treatment times ranged from 120-480 s. To further reduce the mass of the occlusive material an aspiration thrombectomy was performed in all cases leading to a complete recanalization in 6 cases. In 2 cases a remaining stenosis was successfully dilated. Intra-vascular ultrasonic devices can be useful for recanalization of occluded peripheral arteries. With the use of high-energy ultrasound a selective injury of the occlusive material can be induced without damaging the surrounding arterial wall. This selectivity is based on the differences in elasticity between the atherosclerotic plaque and the media layers. Especially if thrombolytic therapy of longer peripheral arterial occlusions fails or is contraindicated ultrasound angioplasty may be a new approach for recanalization.