Safety and Efficacy of Renal Sympathetic Denervation Using Percutaneous Radiofrequency Ablation, a New Hypertension Treatment.

RATIONALE AND

OBJECTIVES

Conventional catheter-based renal sympathetic denervation (RDN) as a treatment for patients with treatment-resistant hypertension cannot ablate renal sympathetic nerves ≥4 mm from the renal artery. We developed a percutaneous radiofrequency ablation (pRFA) method to ablate remote renal sympathetic nerves. This study aimed to assess the feasibility, efficacy, and safety of RDN with pRFA.

MATERIALS AND

METHODS

Fourteen Beagle dogs were divided into RDN and control groups. The RDN group underwent computed tomography (CT)-guided pRFA to ablate the sympathetic nerves around bilateral renal arteries. Renal function (creatinine) and levels of noradrenaline, adrenaline, aldosterone, and renin were measured preoperatively, 3 days, 1 week, and 3 months after the procedure. Three months later, angiography was performed to evaluate renal artery stenosis or occlusion, and sympathetic nerves around the renal artery were evaluated histologically.

RESULTS

The procedure was successful in all cases, but there was one case of renal hemorrhage, and hydronephrosis due to ureteral stricture was seen in three dogs (three of 14 sides). No renal artery stenosis occurred and no dogs died during the procedure or follow-up. Significant decreases from baseline to 3 months later were seen in mean blood levels of noradrenaline (-73%; P < .05) and adrenaline (-55%; P < .05). Histologically, all ablation regions that could be observed showed denervation in sympathetic nerves ≥4 mm from the renal artery.

CONCLUSION

RDN with pRFA was able to ablate renal sympathetic nerves in regions in which conventional methods would have been inadequate, resulting in decreased levels of noradrenaline and adrenaline.