Radiosurgical Ablation of the Renal Nerve in a Porcine Model: A Minimally Invasive Therapeutic Approach to Treat Refractory Hypertension

Abstract

BACKGROUND: Hypertension is strongly associated with cardiovascular diseases such as heart failure, stroke, kidney disease, and has been correlated with an increased risk for heart attack. Current treatment regimens for hypertension are highly inadequate, with reports indicating that only 50.1% of the clinical population with the disease has their blood pressure under control. OBJECTIVE: To study the feasibility of using minimally invasive radiosurgery to ablate the renal nerves as a novel treatment for refractory hypertension, and to assess the safety and efficacy of such an approach. METHODS: A Hanford porcine (miniswine) model (N = 6) was used to investigate the feasibility of using the CyberHeart radiosurgical platform (CyberHeart Inc., Mountain View, CA, USA) to create safe renal nerve ablations. Norepinephrine (NE) levels were measured pre and post treatment. Additionally, renal nerve and arterial histology were studied to examine effect. RESULTS: Plasma norepinephrine levels showed a decrease over the six-month time point. Urea, nitrogen, and creatinine levels showed no changes post procedure. Histology documented no significant arterial injury in targeted areas. Renal nerves documented histologic change consistent with nerve ablation. CONCLUSION: CyberHeart radiosurgery of the renal nerve is feasible and resulted in norepinephrine reduction and renal nerve injury consistent with radiosurgical targeted ablation.