Laparoscopic based renal denervation in a canine neurogenic hypertension model

Chunlai Shao,Boxin Xue,Longjiang Xu,Longsheng Lan,Zhigang Miao,Ting Bo Jiang,Pieter R Stella,Tao You,Guang Rong,Yan Zhou,Yin Yin

doi:10.1186/s12872-020-01546-6

Abstract

BackgroundPrevious renal denervation (RDN) studies showed controversial results in reducing blood pressure. The aim of this study was to provide evidence supporting the effectiveness of laparoscopic-based renal denervation (L-RDN) in treating hypertension.MethodsSixteen Beagle dogs were randomly divided into RDN group (n = 12) and sham group (n = 4). Neurogenic hypertension was generated in all dogs via carotid artery route. L-RDN was performed in the RDN group, with sham operation performed as a control. Blood pressure (BP) changes were recorded at 2, 4, 6, and 8 weeks after the procedure. Changes in serum creatinine (sCr), blood urea nitrogen (BUN) and level of norepinephrine (NE) were analyzed. Histological changes of kidney and renal arteries were also evaluated.ResultsBP and NE levels were significantly elevated after hypertension induction (p < 0.01). Systolic and diastolic BP of RDN group were decreased by 15.5 mmHg and 7.3 mmHg (p < 0.0001 and p = 0.0021, respectively) at the eighth week after L-RDN. Invasive systolic and diastolic BP of RDN group were significantly decreased by 14.5 mmHg and 15.3 mmHg (p < 0.0001). In contrast, there was no significant decrease in blood pressure in the sham group. In addition, RDN group but not the sham group showed a significant decrease in NE levels (p < 0.001), while no significant changes in sCr and BUN were observed in both groups. Pathological examinations showed no discernible damage, tear, or dissection to the renal arteries in RND group.ConclusionsL-RDN lowered BP and NE levels in hypertensive dogs without affecting renal artery morphology and kidney function.

Highlights

Previous renal denervation (RDN) studies showed controversial results in reducing blood pressure
laparoscopic-based renal denervation (L-RDN) reduces Blood pressure (BP) in animals with neurogenic hypertension During 8 weeks after neurogenic hypertensive induction, a continuous elevation of BP in animals was observed in all dogs (Table 1 and Table 2)
Compared with the peak BP recorded by 8 weeks after hypertension induction, systolic blood pressure (SBP) and Diastolic blood pressure (DBP) in the RDN group were decreased by 15.5 mmHg and 7.3 mmHg at the eighth week after the procedure (p < 0.0001 and p = 0.0021) (Table 3)

Summary

Introduction

Previous renal denervation (RDN) studies showed controversial results in reducing blood pressure. Results obtained from SYMPLICITY HTN-3 trial in 2014 questioned the clinical application of RDN therapy This clinical trial was rigorously designed, using randomized and controlled approaches with 535 patients diagnosed as refractory hypertension and including a. No significant difference in the reduction of office SBP was observed between RDN and sham groups by the end of follow-up [3]. These results raised a debate on the efficacy of RDN as a stateof-art therapy for hypertension and led to the suspension of RDN trials including the SYMPLICITY HTN-4 trial and the HTN trial in Japan [4]

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