摘要：
目的 射频消融肾交感神经治疗顽固性高血压在临床上取得一定的疗效,它是通过插入肾动脉的射频导管释放能量,选择性毁坏外膜上的肾交感神经纤维,降低其活性以达到降压的目的,但是射频能量在消融交感神经的穿透能力受消融条件影响.本实验采用体外肝脏中的血管模仿肾动脉,探究不同消融条件下温度场的变化情况.方法 实验中使用含有血管的体外牛肝21个(分解块),采用水流模拟血管中的血液流动,进行射频消融.采集血管壁外周距离消融点上方8～10 mm处组织中的温度以及下游水流中心区的温度,研究该条件下射频消融对组织和血管下游的影响.同时通过改变消融时间以及水流速度,研究不同情况下的消融结果.结果 (1)当消融点与水流中心测温点的距离增加,水流中心消融前后温度ΔT值就会降低.在距离7 cm的情况下,水流温度只上升了1.11°C,说明射频能量对血流下游温度的影响是有限的.(2)随着消融时间由8 min逐渐增加到10 min,水流温度ΔT值与消融点上方组织温度ΔT值均增加.(3)水流速度由0.28 m/s增加到0.365 m/s,则水流温度的ΔT值与消融点上方组织温度ΔT值均下降.(4)射频消融所造成的温度变化,消融点上方组织平均升高3.97°C,水流中心点平均升高2.17°C.结论在10 min内对血管内壁进行消融,消融点外周上方组织和下游水流的温度上升,最大不超过6°C,对血液流动影响有限,基本验证了血管内射频消融术治疗的可行性.%Objective Radiofrequency ablation of renal sympathetic nerve in the treatment of resistant hypertension has obtained certainly effect in clinical. It is inserted into the renal artery to release energy by radiofrequency catheter, selectively destroyed renal sympathetic nerve fibers on the outer membrane, finally to achieve the antihypertensive by reducing the excitability. But the radio-frequency energy penetrating power of sympathetic nerve influenced by ablation conditions. This experiment adopts the ex-vivo hepatic vascular to simulate renal artery to explore the change of temperature field under the different ablation conditions. Methods We used the blood vessels of ex-vivo bovine liver ( n=21 ) , with blood flow simulated by water pump. For collecting the temperature field data for perivascular tissues and the flow downstream, measured from 8-10 mm above the ablation point and the temperature of the downstream water district to study the impact under the ablation conditions. By changing the ablation time and flow velocity, the ablation results were analyzed under different conditions. Results (1) Ablation point was fixed in water inlet, when the distance form ablation point and temperature measuring point in the center of downstream water increased, the temperature ΔT mean value of water reduced. The water temperature rose by only 1. 11 °C with 7 cm distance. (2) Ablation time increases by 8 min to 10 min, the water temperature ΔT value and the temperature above the ablation point ΔT value increased. (3) Flow velocity increased from 0.28 m/s to 0.365 m/s, the ΔT of water temperature and temperature above the ablation point ΔT value were decreased. (4) For the temperature changes caused by radiofrequency ablation, increased by an average of 3. 97 °C above the ablation point, while 2. 17°C in flow center. Conclusions Radiofrequency ablation in blood vessels within 10 min, the temperature of peripheral tissue and downstream flow rise, no more than 6 °C in maximum . The influence on blood flow is limited, basic verified the feasibility of endovascular radiofrequency ablation therapy.
