Vibrato’s LimbSonic Wearable Ultrasound Therapy Device Studied for PAD

October 31, 2023—The PRELUDE early feasibility study evaluated therapeutic ultrasound (TUS) with the LimbSonic device (Vibrato, Inc.) to increase perfusion for the treatment of peripheral artery disease (PAD). LimbSonic is a wearable, noninvasive array of transducers engineered to sonicate the posterior and anterior tibial arteries (and their collaterals) at the level of the calf.

Mahmood Razavi, MD, presented findings from the PRELUDE study during a late-breaking clinical trial session at VIVA23, the Vascular InterVentional Advances annual vascular education symposium held by The VIVA Foundation on October 30 to November 2 in Las Vegas, Nevada.

According to the VIVA press release, the single-arm PRELUDE study enrolled 12 patients with Rutherford class 3 to 5 PAD to receive 30 to 40 treatments of 90-minute TUS with LimbSonic.

Acutely, TUS increased lower extremity perfusion 180% via laser speckle imaging (FlowMet, Medtronic) and laser Doppler, as well as tissue oxygenation via spatial frequency domain imaging (Clarifi, Modulim) and transcutaneous oximetry.

After 30 to 40 TUS sessions, Clarifi tissue oxygenation was elevated 17% above the pretreatment baseline and remained elevated at 1-month posttherapy, with return to baseline by 3 months.

Patient-reported outcome measures (Vascular Quality of Life Questionnaire-6 and Walking Impairment Questionnaire) both improved after TUS sessions but returned to baseline by 6 months. Toe-brachial index did not change acutely. Tolerability, compliance, and patient feedback were excellent, and there were no serious adverse events.

In the absence of an accepted noninvasive metric of response to therapy in PAD/chronic limb-threatening ischemia, future studies will assess clinical endpoints of wound healing, amputation, and revascularization, noted the VIVA press release.