The temperature field simulation of radiofrequency catheter-based renal sympathetic denervation for resistant hypertension.

Renal sympathetic denervation (RSD) by the radiofrequency ablation was used to treat the resistant hypertension in clinic and has achieved curative effect. But the temperature distribution in the artery walls and the blood flow have not been investigated. Finite element method (FEM) based on Comsol Multiphysics 4.3a software was used to simulate the temperature distribution in the renal artery. The results of renal artery temperature distribution as well as blood flow effect on the temperature field were obtained, which demonstrated that the blood velocity is very crucial in the temperature distribution of blood vessel near antenna. When the speed of blood is 0.4 m/s, the highest temperature rise of arterial wall near the antenna is 8.882°C (37°C to 45.882°C) and contralateral artery wall's highest temperature rise is about 5°C (37°C to 42°C). This temperature value can damage renal sympathetic nerves to cure the resistant hypertension. Due to the blood flow, the temperature field stretches to the direction of blood flow. The temperature rise of blood is only in a small range (37°C to 41°C) at both ends of the antenna. The simulation of RSD by the radiofrequency ablation can give doctors a better scheme to avoid the vascular injury in different blood flow rates and radiofrequency voltages.