冠状动脉旁路术中药物扩张大隐静脉的优越性

目的探讨冠状动脉旁路术(CABG)中药物扩张大隐静脉的效果。方法将异搏定10mg、硝酸甘油5mg、5%碳酸氢钠1.0ml、肝素12500U加入林格氏液至500ml配成等渗溶液。22例接受CABG患者在术中暴露大隐静脉时,将此溶液灌注至静脉腔内,同时浇注于静脉表面,并将切取的静脉浸泡于该溶液中。另取同一患者邻近部位的一段大隐静脉作对照,采用加压灌注法扩张,比较两种方法处理的静脉管壁厚度,光镜下血管壁结构的变化。结果压力扩张的静脉管壁变薄;药物扩张使平滑肌舒张,血管腔均匀性扩大。光镜下加压组内皮细胞大量脱落,固有膜细胞水肿明显,肌层细胞出现粘液变性;药物组静脉管壁结构完整。结论药物扩张的大隐静脉管壁结构完整,管腔足够大,有利于桥血管的近、远期通畅。

Relaxation of the saphenous vein by vasodilators during harvesting for coronary artery bypass grafting

Objective: To evaluate the effect of relaxing the saphenous vein by vasodilator solution for coronary artery bypass grafting. Methods:We carried out a vasodilator solution containing the agents of verapamil 10 mg,glyceryl trinitrate 5 mg,5% sodium bicarbonate 10 ml and heparin 12 500U in 500 ml Ringer's isosmotic solution. Vasodilator solution was injected into the lumen and spraied to the surface of the saphenous vein before and after harvested in 22 cases of coronary bypass grafting. It was then immersed into the same solution. Another segment of saphenous vein from the same patient was dilated by syringe forced injection. The thickness of the venous wall as well as the structure were compared between the two methods by optical microscope Results:The forceful distension made the venous wall more thinner.Otherwise,the vasodilator solution made the smooth muscle in venous wall diastolized. The structure of the vein wall in vasodilator solution was intact. However a damaged endothelium and media were observed in forceful distension. Conclusions: Saphenous vein treated by vasodilator could keep intact vein wall structure and achieve a lumen big enough for anastomoses. This method may improve the immediate and long term patency rate of saphenous vein graft.