Percutaneous peripheral ultrasonic angioplasty

We previously reported the initial use of percutaneous catheter delivered ultrasound energy for arterial recanalization in eight patients with peripheral vascular disease. All patients had severe claudication. There were four cases with total occlusion and four with high grade stenoses in a superficial femoral or popliteal artery. A prototype ultrasound probe, with a frequency of 20 kHz and a power output of 20 to 25 watts/cm2 was ensheathed in a 7F catheter and advanced to the occlusions with angiographic guidance. Three of four complete occlusions were recanalized in less than 120 s resulting in a 54 +/- 5% residual diameter stenosis. Ultrasound energy applied to isolated stenoses reduced them by 40%, from 77 +/- 14% to 37 +/- 21%. Further treatment with balloon angioplasty resulted in a mean residual stenosis of 20 +/- 9%. There was no angiographic or clinical evidence of arterial emboli, dissection, spasm, or perforation. Clinical follow-up and Doppler ankle-brachial indices were performed at one, three and six months after combined ultrasound and balloon angioplasty. Two occlusions recurred, both within the first three months, detected by return of claudication and an abnormal ankle/brachial index, and documented by angiography. Repeat balloon angioplasty of standard methods was performed in one, but the vessel again reoccluded. The other five patients with primary technical success have continued patency both clinically and by ankle/brachial index measurement. Percutaneous catheter delivered ultrasound energy appears promising in peripheral vessels to reduce arterial stenoses and recanalize complete arterial obstructions. The long-term findings from this pilot study were insufficient to assess if ultrasound has any effect on restenosis.