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We report about a 29 year old female who developed right-sided leg vein thrombosis over three levels. Thrombectomy was attempted followed by intravenous anticoagulation with heparin. The platelet count dropped acutely from 176,000/microliter to 11,000/microliter after the sixth day. A lung perfusion-ventilation-scintigraphy suggested recent pulmonary embolism by lateral, predominantly right-sided perfusion deficits. ACT scan of the pelvic region showed rethrombosis of the right common iliac vein. The clinical suspicion of heparin-induced thrombocytopenia (HIT) type II was confirmed by a positive heparin-induced platelet aggregation test and the detection of antibodies by heparin-platelet factor 4-ELISA. The patient was treated with lepirudin at body-weight-adapted dose. After recovery of the platelet count to 102,000/microliter within seven days the treatment was changed to Orgaran after exclusion of immunologic cross reactivity. An overlapping oral anticoagulation with Marcoumar was initiated. Although HIT type II usually develops over a few days, acute thrombopenia can also occur. There is therefore no safe diagnostic interval permitting a timely detection.

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.