中文摘要：

目的应用改良的左冠状动脉回旋支结扎方法联合微创手术,制备小型猪急性心肌梗死模型,评估其有效性和稳定性,并探讨其在科研应用中的意义。方法选择3月龄巴马香猪25头,麻醉下行气管插管呼吸机辅助通气,微创开胸结扎左旋支中段,建立急性心肌梗死模型。并于术前、术后1 h、4周行心脏超声评估模型动物的心脏功能,术后4周处死动物,取心脏行TTC染色评估梗死面积及病理变化,统计死亡率和死亡原因。结果结扎术后1 h和4周后心脏功能较术前均明显降低,EF值由（64.2±4.6）%分别降至（48.2±5.3）%和（49.7±6.1）%（P〈0.01）,左心室侧壁室壁厚度变薄,胶原增生。梗死后1 h室颤率17.3%,梗死面积为（19.2±3）%。结论应用改良的左冠状动脉回旋支结扎方法联合微创手术能够建立稳定的猪心肌梗死模型,具有手术创伤小、模型稳定和死亡率低等特点,为相关研究提供了经济、理想的动物模型。

英文摘要：

Objective To develop a better method for preparation of porcine model of acute myocardial infarction by permanent occlusion of the left circumflex coronary artery and minimally invasive surgery,evaluate its validity and stability,and explore its application in experimental studies of ischemic heart diseases. Methods 25 healthy female 3-monthold Bama minipigs,body weight 25 ± 3 kg,were used in this study. The porcine model of myocardial infarction was established by minimally invasive surgery and the left circumflex artery ligation at the site of OM1 posterior position under general anesthesia. Heart function was assessed by echocardiography at 15 min before surgery,1 hour and 4 weeks after surgery.Pathological examination was performed at 4 weeks after the left circumflex artery occlusion. The mortality and cause of death were statistically analyzed. Results The 1-hour and 4-week postoperative cardiac function was considerably de-creased,showing a decreased ejection fraction from 64. 2 ± 4. 6% to 48. 2 ± 5. 3%（ 1hour after MI） and 49. 7 ± 6. 1%（ 4weeks after MI）（ P 0. 01）. Pathological examination revealed that the ventricular wall was thinner and the amount of collagens was increased in the infracted area. The ventricular fibrillation rate at 1-hour after myocardial infarction was 17. 3%and the infarction area was 19. 2%. Conclusions A pig model of acute myocardial infarction can be prepared by our modified left circumflex coronary artery ligation at the obtuse marginal artery（ OM1） and minimally invasive surgery. This model exhibits advantages such as minimal surgical trauma,high stability of the model,and low mortality,therefore,provides an ideal and economic animal model for experimental studies on acute ischemic heart diseases.