Safety of catheter‐based radiofrequency renal denervation on branch renal arteries in a porcine model

Abstract

Objectives We aimed to investigate the safety of radiofrequency (RF)‐renal denervation (RDN) on branch renal arteries (RAs) in a porcine model. Background The efficacy of RF‐RDN was enhanced by treatment of the branch RA, in addition to the main RA. However, there are concerns regarding the safety of RF‐RDN on branch RA because of their smaller diameter and proximity to the kidney. Methods RF was delivered to 24 RA from 12 swine. A total of 8 RA from 4 swine were untreated. Treated RA were examined by angiography and histopathology at 7, 30, and 90 days. Serum creatinine concentration, biophysical parameters during RF delivery, and renal norepinephrine concentration were also assessed. Results Angiography revealed minimal late lumen loss and diameter stenosis in the main and branch RA at any time point. There was no change in serum creatinine after RF‐RDN. Histopathologically, no augmentation of medial damage or neointimal formation was found in branch RA compared with main RA. No or minimal damage to surrounding tissues including the kidneys, ureters, lymph nodes, and muscles was observed at any time point in both the main and branch RA. Equivalent electrode temperature in the main and branch RA was achieved by automatic adjustment of output power by the generator. The renal norepinephrine concentration was significantly lower in the treated group compared with the untreated group. Conclusions RF‐RDN on branch RA was safe in a porcine model, with stenosis‐free healing of treated arteries and negligible kidney damage at 7, 30, and 90 days.

Combined renal and common hepatic artery denervation as a novel approach to reduce cardiometabolic risk: technical approach, feasibility and safety in a pre-clinical model

“…With this study, for the first time we determined the feasibility of a single procedure with a catheter-based technology, to simultaneously denervate multiple organs, including the liver, pancreas, duodenum and kidney. Using the annularity model created from fine histological sectioning and tracing, we uniquely showed that the effective lesion area created by a single iRF system treatment consistently ranged from 6–8 mm from the arterial lumen for both renal and CHA doses (Table 1 ), [ 44 ] which is deeper and more circumferential than those shown by other conventional RF devices [ 45 ]. In addition, the current study demonstrates that a denervation depth of of 6–8 mm from the arterial lumen can achieve a clinically significant reduction in NEPI levels in multiple organs by adequately denervating the perivascular space surrounding the renal arteries and CHA [ 36 ].…”

It's what's inside that matters: Getting to the source in renal denervation

“…11 We agree with the authors that RDN of branch RAs needs further investigation, and congratulate them on their study demonstrating the safety of radiofrequency RDN on branch renal arteries, specifically in that there was no histopathological evidence of artery stenosis or kidney injury after ablation. 1 In their study, Sakaoka et al 1 13 Recent studies however suggest it is ablation of afferent nerves that is the putative factor in the antihypertensive effects of RDN. 14,15 The study by Sakaoka et al 1 used a reduction in NE as a surrogate for effective RDN, which is a common methodology in other studies as well.…”

“…We read with interest the article by Sakaoka et al, 1 in Catheterization and Cardiovascular Interventions entitled, "Safety of catheter-based radiofrequency renal denervation on branch renal arteries in a porcine model. "…”

Comparison of ablation characteristics of three different radiofrequency applicators in renal sympathetic denervation

“…Qu et al [10] confirmed that a self-developed novel four-electrode RFA catheter (Spark) significantly reduced the levels of BP and plasma renin, aldosterone, as well as angiotensin I and II in a porcine model. Sakaoka et al [11] investigated the safety of RDN using the IberisBloom system in a porcine model. The results indicated no change in serum creatinine after RF-RDN, no augmentation of medial damage or neointimal formation in the renal artery, and no or minimal damage to surrounding tissue.…”