Investigation On The Efficiency And Safety Of Renanl Denervation By Ultrasound Catheter

Objective To investigate the temperature distribution around the peri-renal arterial tissue using self-developed ultrasound renal denervation (RDN) catheter in different parameter combinations, and observe the effect of RDN in different parameter combinations in vivo.Methods The ultrasound ablations were performed in renal artery model with different energy dose (1.0 W,1.5 W and 3.0 W) and duration (10 s,15 s and 30 s). The temperature was recorded in different distance to the lumen by the needle type thermocouple.The ablation parameter combinations which caused an over 51℃ were selected for in vivo study. The blood pressure and noradrenaline concentration was measured at the baseline and one week post-ablation. Histological examination of the renal artery and the peri-arterial tissue was done in the study.Results Temperature was positively correlated with the energy dose and ablation duration, and reached the maximum at 5.0 mm away from the lumen. The 1.5 W×30 s,3.0 W×15 s, and 3.0 W×30 s groups could achieve the effective temperature at 5 mm and 10 mm. It showed significant decrease of systolic blood pressure and diastolic blood pressure in the ablation groups(P<0.05,[8.77±0.78]mmHg/[6.44±0.60]mmHg, [9.78±1.86] mmHg/[6.36±1.49]mmHg and [13.34±1.75] mmHg/[12.20±2.44]mmHg, respectively),and a histologic examination revealed the cavitation of nerve fibers.Conclusion The effective ablation temperature emerge at the distance of 5.0mm to 7.0mm from the artery lumen within the peri-renal artery tissues by 10.0MHz ultrasonic catheter. The vivo study confirms the efficiency and safety of RDN procedure using the catheter.