超声导管肾去交感化的有效性及安全性

Efficiency and safety of renal denervation by ultrasound catheter

目的 探索自行研发10.0 MHz超声导管以不同参数组合消融肾动脉周围神经时温度场的分布, 并观察在体条件下不同剂量声能产生的去交感神经效果。方法 超声导管消融犬离体肾动脉, 以针式热电偶检测不同声功率消融不同时间时距肾动脉内膜不同距离处的温度。选择温度≥51℃的组合行活体消融。测量消融前及消融后1周的血压, 取肾动脉及周围组织行病理学检查。结果 肾动脉周围温度与消融功率及时间呈正相关,各组温度均在5 mm处达峰值。1.5 W×30 s消融组、3.0 W×15 s消融组及3.0 W×30 s消融组在5 mm、7 mm处达有效消融温度。消融1周后消融组收缩压和舒张压下降幅度分别为（8.77±0.78）mmHg/（6.44±0.60）mmHg, （9.78±1.86）mmHg/（6.36±1.49）mmHg, （13.34±1.75）mmHg/（12.20±2.44）mmHg（P〈0.05）。肉眼观测肾动脉周围无损伤, HE染色见肾周围神经空泡样变。结论 10.0 MHz超声导管消融肾周围神经, 在距内膜5-7 mm处达有效温度;在体实验初步证明其应用于肾去交感的有效性及安全性。

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 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 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 mm to 7 mm from the artery lumen within the peri-renal artery tissues by 10.0 MHz ultrasonic catheter. The vivo study confirms the efficiency and safety of RDN procedure using the catheter.