体外循环停跳和不停跳手术对心肌保护作用的研究

Study of Myocardial Protection with Methods of Beating Heart and Arrested Heart on CPB

目的 :探讨浅低温体外循环 (CPB)下温血停搏液持续灌注和不停跳行心内直视手术对心肌的保护作用。方法 :18只同种健康山羊随机分为 3组 ,每组 6只。 I组冷晶体间断灌注组 , 组温血停搏液持续灌注组 , 组不停跳组。分别在 CPB的不同时刻测定心肌组织丙二醛 (MDA)的含量及静脉血血浆肾素活性 (PRA)、血管紧张素 (AII)的含量 ,并切取心肌组织电镜观察超微结构的改变。结果 :I组 CPB期间 MDA、PRA、AII逐渐升高 ,恢复正常灌注后升高更明显 ; 组、 组虽也有所升高 ,但较 I组低。超微结构的改变示 I组改变明显 ,而 组、 组则基本不变。结论 :温血停搏液持续灌注和不停跳行心内直视手术可有效避免心肌的缺血和再灌注损伤 ,有良好的心肌保护作用。

Objective:To investigate the myocardial protective effects with methods of beating heart and arrested heart in goats undergoing open heart surgery with cardiopulmonary bypass (CPB).Methods:Eighteen healthy and homogeneous goats were randomly divided into three groups:group Ⅰ ( n =6),intermittent cold crystalloid cardioplegia,group Ⅱ ( n =6),continuous warm blood cardioplegia and group Ⅲ ( n =6),beating heart group.Group Ⅱ and group Ⅲ were operated with mild hypothermic cardiopulmonary bypass.The changes of MDA in myocardium of right ventricles and PRA?AII vein blood were measured separately.The myocardial tissues were incised to observe ultrastructural changes.Results:In group I,contents of MDA and PRA?AII rose significantly during CPB time,especially when blood was reperfused normally.While in group Ⅱ and group Ⅲ the levels were lower than those in group Ⅰ at the same time.There was no difference between group Ⅱ and group Ⅲ.Ultrastructural changes were distinct in group Ⅰ while slight in group Ⅱ and group Ⅲ.Conclusions:The methods of continuous warm blood cardioplegia and beating heart can prevent ischemia reperfusion injury and protect heart better.