CWJeong, J Budrewicz, JH Keating, M Williams-Fritze, P Markham, AR Tzafriri. ‘Twenty Four Week Safety and Efficacy of a Novel Extravascular Renal Denervation Device in a Porcine Model at an Elevated Temperature Setting.’ Presented at: CRT 2025.
Background: Extravascular radiofrequency (RF) renal denervation (RDN) of pigs at nominal dose (50oC/70sec) using a device that circumferentially wraps the renal artery exhibited good acute and chronic safety in the porcine model. Here we evaluate the 24 week effects of this device after RDN at elevated temperatures in the same model.
Methods: On Day 0, 30 pigs underwent bilateral extravascular RDN at proximal and distal sites using the HyperQure™ RDN System (DeepQure Inc., Seoul, Republic of Korea), with at least 1 nominal dose (50oC/70sec) and 1 elevated dose (53oC/70sec) per artery. Abdominal CT scans were performed pre/post procedure in renal arteries (outer diameters=2-10 mm). Acute performance was evaluated by 3 surgeons. Animal health was regularly monitored. Animals were euthanized at Days 7, 28, 84 and 168, and subjected to a comprehensive necropsy. Tissues were collected for histology (H&E and tyrosine hydroxylase (TH)) and a portion of each kidney was analyzed for Norepinephrine D6 (NEPI) content.
Results: All treatments achieved the highest average acute performance scores with no observed post-treatment arterial injuries or spasms. All animals exhibited good health. CT scans showed minimal to absent stenosis. Acceptable arterial and periarterial/adventitial tissue responses were observed grossly and histologically, including presence of nerve response to treatment, absence of adverse events, and complete healing and extensive remodeling of arterial and periarterial tissues by Days 84 and 168. Renal artery medial necrosis/smooth muscle cell loss was negligible across artery sizes, with no mural injury/disruption, luminal occlusion or thrombosis. Adventitial/perivascular findings were consistent with initial RF-induced responses resolving over time. Histologic renal nerve responses decreased over time, being notable in TH-stained sections at Days 7 and 28, with prominent subsequent decrease in incidence at Days 84 and 168, attributed to repair/regeneration. Relative to historical baseline levels, NEPI concentration declined by ≥50% at Days 7-84 and 26% at Day 168.
Conclusions: Extravascular RDN of large and small arteries at elevated temperatures via laparoscopic access was safe and efficacious in pigs.
JACC: Cardiovascular Interventions Volume 18, Issue 4, Supplement, 24 February 2025, Pages S36-S37