肺静脉内射频消融温度与肺静脉狭窄的关系研究

The relationship between various temperature of catheter ablation and pulmonary vein stenosis

目的 探讨肺静脉内不同温度射频消融与肺静脉狭窄的关系。方法 健康杂种犬３０只，分成３组，经房间隔途径将温控电极导管置入肺静脉内进行消融，各组能量分别为５０℃×６０ｓ，６０℃×６０ｓ，７０℃×６０ｓ。消融前、后均行选择性肺静脉造影，术后留养３个月，重复肺静脉造影后，处死，取心肌、肺静脉及肺组织作病理检查。结果５０℃组１只犬在行房间隔穿刺时因心包填塞死亡，其余均顺利完成试验。共在肺静脉内７２处行点状消融，５０℃组、６０℃组、７０℃组分别为２０、２６、２６处。右上肺静脉、右下肺静脉、左上肺静脉和左下肺静脉分别为１３、９、２７、２３处。５０℃组肺静脉于消融后即刻及３个月后均未见狭窄。６０℃组消融后即刻发现５处狭窄，３个月后仅遗留１处狭窄。７０℃组消融后即刻有１２处狭窄，３个月后复查仍有７处狭窄，发生率均明显高于５０℃组及６０℃组。结论 肺静脉内射频消融温度为５０℃及６０℃时较为安全，７０℃时肺静脉狭窄的发生率明显上升，提示消融温度应控制在６０℃以减少肺静脉狭窄的形成。

Objective The purpose of this study is to reveal the relationship between various temperature of radiofrequency catheter ablation (RFCA)and pulmonary vein (PV)stenosis. Methods Thirty dogs were divided into 3 groups. After pulmonary arteriography, catheters were positioned in the PVs via a transseptal approach under fluo- roscopy, and radiofrequency energy was delivered for 60 seconds at a temperature of 50℃ (group A), 60℃ (group B) and 70℃ (group C) respectively. Selective pulmonary venography (SPV)was performed before and immediately af- ter ablation procedure. Three months later, SPV was repeated and dogs were put to death. The cardiac muscle, pulmonary veins and adjacent lung tissues were obtained for pathological examination. Results All dogs had finished this study, except for one dog in group A died of pericardial tamponade during transseptal puncture. Focal ablation was performed in a total amount of 72 sites, including 20 sites in group A, 26 sites in group B and 26 sites in group C. RFCA was applied to right superior PV (13 sites), right inferior PV (9 sites), left superior PV (27 sites)and left inferior PV (23 sites)respectively. No PV stenosis was found in group A within 3 months. Five (19.2%)PV stenosis were found in group B and 1 (3.8%)remained at 3 months follow-up. Twelve (46.2%)occurred in group C and 7 (26.9%)remained after 3 months. Conclusion Compared with group A and group B, the incidence of PV stenosis tends to be higher in group C. PV stenosis occurring immediately after catheter ablation might be caused by vasospasm and some might relieve spontaneously.