Does a laparoscopic ablation system for complete circumferential renal sympathetic denervation reduce blood pressure and sympathetic signals in a porcine model?
A novel laparoscopic ablation system achieved complete circumferential renal denervation, significantly reducing blood pressure and sympathetic nerve signals in a porcine model.
GOAL: The catheter-based renal denervation (RDN) showed promising results for patients in lowering BP, but there were also many non-responders. One of the possible reasons was the incomplete neural ablation due to the ablation of renal nerves at random sites resulting in asymmetric innervation patterns along the renal artery. METHODS: We developed a laparoscopic ablation system that is optimized for complete RDN regardless of renal arterial innervation and size. To demonstrate its effectiveness, we evaluated the system using computational simulation and 28-day survival model using pigs. RESULTS: The ablations were focused around the tunica externa, and the ablation patterns could be predicted numerically during RDN treatment. In the animal study, the mean reduction of systolic BP and diastolic BP in the bilateral main renal arteries was 22.8 mmHg and 14.4 mmHg (P<0.001), respectively. The respond to immunostaining targeting tyrosine hydroxylase was significantly reduced at treatment site (108.2 ± 7.5 (control) vs. 63.4 ± 8.7 (treatment), P<0.001), and an increased degree of sympathetic signals interruption to kidneys was associated with the efficacy of RDN. CONCLUSION: The laparoscopic ablation system achieved complete circumferential RDN at the treatment site and could numerically predict the ablation patterns. SIGNIFICANCE: These findings clearly suggest that the proposed system can significantly improve the RDN effectiveness by reducing the variation to the percentage of injured nerves and open up a new opportunity to treat uncontrolled hypertension.
Baik et al. (Tue,) studied this question.