11 - Evaluation of Ultrasound Renal Denervation for Refractory Hypertension

Purpose: The aim of this study was to determine early clinical outcomes and renal artery ultrasound changes after ultrasound renal denervation (uRDN) for resistant hypertension.

Materials and Methods: This was an IRB-approved single center retrospective study. Patients who underwent uRDN (Paradise Ultrasound Renal Denervation System, Recor Medical, Palo Alto, CA) for resistant hypertension on maximal anti-hypertensive therapy and could not achieve their target blood pressure are included. Secondary causes of hypertension prior to intervention were excluded. A total of 8 patients were treated (6 female; mean age: 51.9 ± 15.4 years). Procedural details, as well as pre- and post-intervention blood pressure, imaging and laboratory values were recorded. Changes in blood pressure, number of anti-hypertensive medications, kidney function, and peak systolic velocity (PSV) of the renal artery on duplex ultrasound (US) were analyzed.

Results: Mean follow up duration was 5.8 ± 4.5 months. A total of 15 renal arteries were treated among 8 patients. One patient had multiple left renal arteries that were too small in diameter to treat with uRDN. Following uRDN, there was a significant decrease in the mean systolic blood pressure (183.1 ± 38.3 mmHg to 143.8 ± 14.6 mmHg, p=0.03), the mean number of antihypertensive medications (5.5 ± 1.5 to 3.4 ± 1.8, p=0.04), and renal artery PSV (168.4 ± 92.3 cm/s versus 107.4 ± 46.8 cm/s, p=0.03). No significant change in renal function was observed (p=0.92). There were 3 cases of arterial spasm and 1 case of renal artery dissection which was treated with renal artery stent placement.

Conclusion: This study demonstrated that uRDN can effectively lower blood pressure and the number of antihypertensive medications for patients with refractory hypertension. Duplex US showed a decrease in mean renal artery PSV suggesting uRDN treatment by decreasing sympathetic drive which could be a biomarker for successful uRDN treatment.