Transcatheter microwave ablation can deliver deep and circumferential perivascular nerve injury without significant arterial injury to provide effective renal denervation. Issue 10 (October 2019)

• Record Type: Journal Article
• Authors: Qian, Pierre C.; Barry, Michael A.; Lu, Juntang; Al-Raisi, Sara; Mina, Ashraf; Ryan, Joshua; Bandodkar, Sushil; Alvarez, Shirley; James, Virginia; Ronquillo, John; Varikatt, Winny; Clayton, Zoe; Chong, James; Kovoor, Pramesh; Pouliopoulos, Jim; McEwan, Alistair; Thiagalingam, Aravinda; Thomas, Stuart P.
• Is Part Of: Journal of hypertension. Volume 37:Issue 10(2019:Oct.)
• Publication Date: 2019-10
• Subjects: catheter ablation -- hypertension -- microwave -- renal denervation -- renal nerves; Hypertension -- Periodicals; Hypertension -- Periodicals; 616.132005
• DOI: 10.1097/HJH.0000000000002104
• Languages: English
• ISSNs: 1473-5598

Abstract

Abstract : Background: Clinical studies of transcatheter radiofrequency renal denervation for treating hypertension have been hampered by the lack of consistent denervation efficacy. We aimed to demonstrate the short-term efficacy and safety of transcatheter microwave renal denervation. Methods: A novel 7F microwave system was validated in a sheep model of unilateral renal denervation. Up to two microwave ablations were delivered to each artery with maximum power at 100–110 W for 480 s. Results: Catheter deployment and ablation was successful in all 19 targeted vessel segments, and ablation produced substantial circumferential perivascular injury; median ablation lesion area greater than 395 [interquartile range (IQR) 251–437] mm 2, depth 17.1 (IQR 15.8–18.4) mm, length 16 (IQR 12–20) mm, without collateral visceral injury. Limiting power to 100 W minimized arterial injury, while maintaining a deep circumferential perivascular ablation. Microwave denervation reduced median functional sympathetic nerve surface area at the renal hilum on antityrosine hydroxylase staining by 100% (IQR 87–100%, P = 0.0039), and median renal cortical norepinephrine content by 83% (IQR 76–92%, P = 0.0078), compared to the paired control kidney at 2–3 weeks postprocedure. Conclusion: Transcatheter microwave ablation can produce deep circumferential perivascular ablations over a long segment of the renal artery without significant arterial or collateral visceral injury to provide effective renal denervation.