心脏跳动下心脏手术心肌保护效果的临床观察

Clinical study of myocardial protection in open-heart surgery on beating heart

目的 探讨心脏不停跳心内直视手术的临床应用效果和心肌保护效果。方法 临床随机对照前瞻性研究 ,4 0例单纯简单先心病患者随机分为两组 ,每组各 2 0例。对照组 (A组 )在常规心脏停跳下行心内直视手术 ;实验组 (B组 )不阻断升主动脉 ,在浅低温体外循环、心脏跳动下完成心内直视手术。两组分别于术前、停机即刻、术后 6h、12h、2 4h和 4 8h 6个时点取外周静脉血测定心肌酶 (CK)、肌钙蛋白I(cTnI)、丙二醛 (MDA)的血浆浓度 ,同时监测心功能各项指标。结果 停机即刻、术后 6h和 12h ,A组较B组CK显著升高 (P <0 .0 1) ;cTnIA组停机即刻至 4 8h均高于B组 ;A组MDA停机即刻和术后 6h高于B组 (P <0 .0 5 )。不停跳组平均体外循环时间 (5 2 .4± 17.5 )min ,明显低于停跳组 (84 .8± 16 .6 )min(P <0 .0 1)。循环和血气分析指标两组无明显差别 (P >0 .0 5 )。B组无空气栓塞并发症。结论 浅低温不停跳心内直视手术避免了低温和缺血再灌注引起的心肌损害 ,具有明确的心肌保护作用 ,但仍存在一定的心肌损伤。另外这种手术方法存在血液成分破坏较严重的不足。

Objective To evaluate the effect of myocardial protection of open-heart surgery with beating-heart and mild hypothermic cardiopulmonary bypass (CPB). Methods Thirty patients with simple congenital heart defect were randomly divided into 2 groups. Patients in control group (group A) underwent the middle hypothermal CPB with cardial arrest, while in experiment group(group B) without aortic cross-clamping under light hypothermal CPB on beating heart. Blood samples from peripheral venae were used for assessing the level of creatine kinase (CK),troponin I (cTn I),and malondiaehye (MDA) at different time of the operation. The myocardial function was observed. Results In group A the level of CK was higher than that in group B at the time of pump stopping, 6 h and 12 h after operation(P<0.01). cTn I in group A was higher than that in group B from pump stopping to 48 h after the operation(P<0.05). The CPB time was (52.4±17.5)min in group A , which was shorter than that in group B. Pump stopped immediately at the end of operation and only a few patients needed low dose of dopamine to suppport the circulation and no air embolism occurred in group B. Conclusion Open-heart surgery with beating-heart and mild hypothermic cardiopulmonary bypass(CPB) have definite effect on myocardial protection, but the dest ruction of blood constituents is the main problem.