Kona Medical said this week that it’s launched a clinical trial of the non-invasive renal denervation device for treating hypertension it calls Surround Sound.

Unlike other renal ablation systems, Kona’s Surround Sound device uses external ultrasound to non-invasively target the nerves leading to and from the kidney.

Bellevue, Wash.- and Menlo Park, Calif.-based Kona said its Wave IV trial is slated to enroll 132 patients in a randomized, sham-controlled, double-blinded trial study to evaluate Surround Sound’s safety and efficacy – including in patients who have already undergone unsuccessful renal denervation treatments.

"Initiation of Wave IV is an important milestone in the development and commercialization of Surround Sound," founder & CEO Dr. Michael Gertner said in prepared remarks. "This will be the first randomized, sham-controlled renal denervation trial since the Medtronic HTN-3 trial. We are excited to work with clinicians around the world to complete this important study."

"We are pleased to participate in this randomized, sham-controlled trial of Kona Medical’s non-invasive therapy for resistant hypertension," added principal investigator Dr. Roland Schmieder of the University Hospital Erlangen, Germany. "With its novel approach, external ultrasound offers potential benefits over existing catheter-based renal denervation techniques. If proven successful, non-invasive renal denervation could greatly reduce costs of treatment and increase access for the millions of people worldwide whose blood pressure is not adequately controlled today."

Renal denervation, once 1 of medtech’s hottest fronts, lost a significant amount of heat early this year after Medtronic (NYSE:MDT) said its Symplicity RDN device failed to meet the efficacy endpoint in a U.S. pivotal trial. The result prompted Covidien to ditch its RDN program and prompted Boston Scientific (NYSE:BSX) and St. Jude Medical (NYSE:STJ) to lower their financial expectations for their RDN offerings, the Vessix and EnLightn devices, respectively.

Last year Kona closed a $10 million Series D round, saying at the time that it planned to use the proceeds to enter the Chinese RDN market.