A novel non-vascular system to treat resistant hypertension

To evaluate in a preclinical model the utility of a monopolar electrode catheter delivering radiofrequency (RF) energy placed into the renal pelvis in order to treat resistant hypertension (RH).

Sixteen female domestic swine weighing 60-65 kg underwent renal pelvic denervation via ureteral access. Three animals were euthanised immediately after delivery of RF energy; five animals were allowed to survive for seven days, six animals were allowed to survive for 14 days and two animals were allowed to survive for 30 days. Renal cortical norepinephrine levels were measured in all groups of animals. Histopathology of the treated zone was performed to confirm nerve damage. Renal cortical tissue was harvested for determination of tissue norepinephrine by HPLC. The kidneys were then profusion-fixed and harvested for histopathologic analysis. Mean reduction of norepinephrine levels was 60.4% compared to control. Histopathology confirmed nerve ablation in the treated zone.

In this small, preclinical study, we introduce a new non-vascular system to treat resistant hypertension. If the current clinical experience confirms efficacy and safety, this approach may be one way to treat patients who cannot be treated with the standard percutaneous arterial devices.