激光心肌孔道损伤与修复的实验研究

Experimental Study on Channels Injury and Repair of Myocardium After Transmyocardial Laser Revascularization

目的 研究激光心肌血运重建术 (TMLR)后心肌孔道损伤与修复的形态学变化。方法 采用中国实验小型猪 13只 ,于左冠状动脉旋支起始段放置Ameroid收缩环 ,6周后形成慢性缺血心肌模型 ,应用高功率(80 0W )CO2 激光于左心室侧壁进行激光打孔。实验动物分别于心肌激光打孔后 1h、18h、3天、7天、6周、3个月及 6个月处死 ,观察激光孔道损伤与修复的形态学变化。结果 孔道早期残留宽窄不一的管腔 ,以后随着组织的修复及改建 ,部分孔道可以长期开放 ,部分孔道机化再通 ,形成许多与孔道平行的血管腔隙 ,新生血管与原心肌血管相通。结论 TMLR后激光孔道可以长期开放。

Objective The aim of this paper was to study the changes of myocardium channel after transmyocardial laser revascularization(TMLR) with CO 2 laser. Methods The model of chronic ischemic myocardium was created in 13 experimental Chinese minipigs by putting an Ameroid constrictor around the proximal left circumflex artery. Channels were created in the ischemic area of ventricular wall of each pig by using carbon dioxide (CO 2)laser. The animals were sacrificed in 1 hour, 18 hours, 3 days, 7 days, 6 weeks, 3 months and 6 months after TMLR, recpetively. Sections from the ischemic area were submitted for histologic and scanning electronmicroscopic analysis. Results The laser induced channels showed thermal damage to the surrounding tissue at early stage. Up to 6 weeks, some of the channels remained patent and some of them showed organizition and recanalization. The channels connected with surounding microvasculature of myocardium. Conclusion Most of the transmurul channels can be patent for a long period after TMLR.