Radiofrequency renal artery denervation: technical issues of different approaches and safety

Objective . To describe the technical issues and safety of renal denervation (RD) when using a multielectrode radiofrequency (RF) bipolar balloon catheter, a multielectrode unipolar RF spiral catheter, and an electrophysiological (EP) 3,5-mm RF ablation catheter. Design and methods . Between 2016 and 2019, 54 patients undergoing renal artery (RA) denervation were included into a prospective observational study: 27 procedures were performed using the balloon technology, 21 — using the spiral; and 6 — using a steerable irrigated EP catheter under three-dimensional electroanatomical guidance. In 50 patients RD was performed due to resistant arterial hypertension, and in 4 — due to intractable ventricular tachyarrhythmias. Results . The use of the spiral catheter was associated with a higher number of RF points in the RA, when compared with balloon ablation and EP catheter ablation (22,3 ± 9,6 vs. 13,4 ± 5,5 vs. 8,7 ± 2,1, p < 0,01). In the balloon ablation group, a direct correlation between the number of RF points and the sharpest RA angle was found (correlation coefficient — 0,82). We observed the following complications: in the balloon ablation group — 1 dissection of the RA and 1 aneurysm of the right femoral artery (7,4 %); in the spiral ablation group — 1 aneurysm and 1 pulsating hematoma of the right femoral artery (9,5 %); in the electrophysiological electrode ablation group — 1 dissection of the RA, 1 aneurysm of the right femoral artery (33,4 %). Conclusions . The use of the spiral multielectrode catheter is associated with the higher number of RF applications, including ablation inside distal branches. The number of RF points depends on the artery tortuosity when performing balloon-based ablation. Manipulations inside the RA using the EP catheter might not be safe.