介入封堵左前降支建立室壁瘤动物模型(英文)

Ventricular aneurysm animal model establishment by plugging the left anterior descending branch

背景： 有资料表明，猪的心血管系统的生物学特性与人类有极大的相似性，其代谢、免疫系统、疾病的发生机制等方面与人类有99%的共源性。目的：拟通过介入封堵左前降支建立规范化的猪室壁瘤模型。设计、时间及地点：动物观察实验，于2005-12/2007-07在同济大学附属同济医院功能材料实验室及动物实验中心完成。材料：枫泾家猪13只， 雌雄不拘，体质量30~40 kg。方法：在充分腹腔、静脉麻醉诱导下，对13只家猪行经皮股动脉穿刺，置入7号动脉鞘管，在数字减影血管造影下经鞘管在导丝引导下通过球囊将“WYW”冠状动脉栓塞装置输送至前降支第一对角支开口处远端，扩张球囊，释放栓塞装置，再次行冠脉造影，确认栓塞装置对冠脉前降支已形成可靠的封堵。术中、术后严密心电血压监测并予血管活性药物维持生命体征平稳。主要观察指标：观测心电图、血清心肌酶谱、心肌核素显像、超声心动图、心血管照影及病理学变化。结果：1只动物在术前死于麻醉意外，6只在封堵过程中死于心室颤动，其余6只均存活。术后4周复查冠脉照影显示，远端血流已100%阻塞，左室照影示心尖部及左室前壁室壁运动消失。栓塞前心电监护显示心电图呈正常表现，阻断后即刻出现ST段持续性抬高，R波振幅降低，T波高耸，ST-T融合波出现，胸前导联明显。ST段约2周后降回基线，术后4周可见病理性Q波。术后12 h血清肌钙蛋白测定较术前均有不同程度升高 （P 〈 0.01）。放射性核素心肌显像可见心尖和左室前壁呈放射性的核素灌注充盈缺损，室壁变薄，有室壁瘤形成。心脏超声显示，6只动物均出现室壁局部节段性收缩运动减弱，以左室前壁及心尖部尤显。苏木精－伊红染色后光镜下观察可见心尖梗死区心肌纤维消失、被胶原纤维所取代，其间有少量毛细血管；右室前壁梗死边缘区有残留心肌纤维核固缩、溶解，除胶原纤维填充外还有较多炎症细胞和毛细血管浸润。结论：应用“WYW”介入栓塞法建立的室壁瘤模型较接近临床病理生理演变过程，效果确切可靠。

BACKGROUND： Biological characteristics of porcine cardiovascular system are similar to that of human. The metabolism, immune system, mechanism of disease have 99% homology between pig and human. OBJECTIVE： To develop ventricular aneurysm animal models by plugging left anterior descending branch. DESIGN, TIME AND SETTING： The animal observational study was performed at the Laboratory of Functional Material and Animal Experimental Center, Tongji Hospital Affiliated to Tongji University from December 2005 to July 2007. MATERIALS： A total of 13 pigs, of both genders, weighing 30-40 kg, were used in this study. METHODS： After abdominal cavity and intravenous anesthesia, balloon with ＂WYW＂ stent was put into 13 pig left anterior descending coronary artery following No. 7 artery sheathing canal was implanted. The balloon was dilated and the stent was positioned into the distal point of the first diagonal branch to obstruct the artery under digital subtraction angiography. During and after the operation, electrocardiogram was monitored and recorded to maintain stable vital sign. MAIN OUTCOME MEASURES： Electrocardiogram, serum myocardial enzymes, myocardial radionuclide imaging, echocardiography and angiography and pathological changes were observed. RESULTS： One rat died of anesthetic accident before surgery. Six rats died from ventricular fibrillation during plugging, and the other 6 rats were survival. 4 weeks following surgery, coronary angiography showed blood flow at distal end was blocked 100%. Left ventricle angiography demonstrated that wall motion at apex of the heart and the left ventricle disappeared. Before embolism, electrocardio-monitoring displayed electrocardiogram was normal. After plugging, ST segment was raised continuously; amplitude of R wave was decreased; T wave was erected; ST-T fusion wave appeared; precordial leads were obvious. ST segment was reduced to basic level 2 week later, and pathological Q wave appeared 4 weeks later. Serum treponin was increased at 12 hours following surgery compared with before surgery （P 〈 0.01）. Radioactive nuclide myocardial imaging revealed that cardiac apex and left ventricle anterior wall showed radioactive nuclide perfusion filling defect, thin ventricular wall and ventricular aneurysm. Cardiac ultrasonic showed six pigs suffered from weaken segmentation contraction motor of local ventricular wall, especially at anterior wall of the left ventricle and cardiac apex. After hematoxylin-eosin staining, optical microscope exhibited that cardiac muscle fiber disappeared, which was replaced by collagen fiber, with the presence of some capillary at the infarct of cardiac apex. Pyknosis and lysis of residual cardiac muscle fiber were visible in infarct region of anterior wall of the right ventricle. Many inflammatory cells and capillary infiltration were detected besides collagen fiber filling. CONCLUSION： The new approach of ＂WYW＂ intervention embolization is able to develop the ventricular aneurysm animal model, which is similar to clinical pathophysiological variation. The outcome is precise and reliable.