Ultrasound angioplasty: an update review

The use of therapeutic ultrasound to treat atherosclerosis and thrombosis has been appreciated for decades. However, it was only the explosive growth of angioplasty in the 1980s that brought real momentum to the development of therapeutic catheter ultrasound. The idea behind this technique was that ultrasound, by its bioselectivity, might provide a solution to some of the shortcomings of balloon angioplasty. In the late 1980s, two groups, headed by Rosenschein and Siegel, began serious work to address the technical challenge of developing a catheter that would provide efficient external ultrasound energy to the lesion. Current catheters from both groups consist of a solid metal probe which is connected to a piezoelectric transducer. In the distal segment, the wire is specially designed to increase energy delivery. Initial in vitro studies concentrated on understanding the mechanisms of ablation and the effects of mechanical vibration, thermal phenomena and cavitation. Clinical studies of ultrasound ablation were initially performed in peripheral vessels. Later, after safety had been assured, clinical studies involving the coronary arteries began to take place. In this article we aim to update the reader about the experimental and limited clinical experience in this novel technique for treating different kinds of arterial obstruction.