Intravascular sonotherapy for treatment of in-stent restenosis

Intravascular sonotherapy has been introduced as a potential alternative to brachytherapy for prophylactic and therapeutic application in patients after coronary stent placement. Sonotherapy represents a non-ablative, non-thermal form of therapeutic ultrasound. The ultrasound catheter with diameter between 4 and 5 French carries up to 6 electronic elements operating currently at a frequency of 1.0 to 1.4 MHz. Animal studies have proven the efficacy of intravascular sonotherapy with respect to a reduction of neointimal ingrowth after stent placement. A first multicenter observational study in humans has documented that its application is safe and yields favorable results after coronary stenting, also in complex patient and lesion characteristics. This technique is currently under investigation in large prospective, multicenter, randomized studies performed in patients with de novo stenting or documented in-stent restenosis.