Abegunewardene Nico, Vosseler Markus, Gori Tommaso, Hoffmann Nico, Schmidt Kai-Helge, Becker Dietmar, Kreitner Karl-Friedrich, Petersen Steffen E, Schreiber Laura M, Horstick Georg, Münzel Thomas
Second Medical Clinic, Johannes Gutenberg-University Mainz, Mainz, Germany.
Cardiovasc Intervent Radiol. 2009 Sep;32(5):1033-41. doi: 10.1007/s00270-009-9596-5. Epub 2009 May 27.
The surgical technique employed to determine an experimental ischemic damage is a major factor in the subsequent process of myocardial scar development. We set out to establish a minimally invasive porcine model of myocardial infarction using cardiac contrast-enhanced magnetic resonance imaging (ce-MRI) as the basic diagnostic tool. Twenty-seven domestic pigs were randomized to either temporary or permanent occlusion of the left anterior descending artery (LAD). Temporary occlusion was achieved by inflation of a percutaneous balloon in the left anterior descending artery directly beyond the second diagonal branch. Occlusion was maintained for 30 or 45 min, followed by reperfusion. Permanent occlusion was achieved via thrombin injection. Thirteen animals died peri- or postinterventionally due to arrhythmias. Fourteen animals survived the 30-min ischemia (four animals; group 1), the 45-min ischemia (six animals; group 2), or the permanent occlusion (4 animals; group 3). Coronary angiography and ce-MRI were performed 8 weeks after coronary occlusion to document the coronary flow grade and the size of myocardial scar tissue. The LAD was patent in all animals in groups 1 and 2, with normal TIMI flow; in group 3 animals, the LAD was totally occluded. Fibrosis of the left ventricle in group 1 (4.9 +/- 4.4%; p = 0.008) and group 2 (9.4 +/- 2.9%; p = 0.05) was significantly lower than in group 3 (14.5 +/- 3.9%). Wall thickness of the ischemic area was significantly lower in group 3 versus group 1 and group 2 (2.9 +/- 0.3, 5.9 +/- 0.7, and 6.1 +/- 0.7 mm; p = 0.005). The extent of late enhancement of the left ventricle was also significantly higher in group 3 (16.9 +/- 2.1%) compared to group 1 (5.3 +/- 5.4%; p = 0.003) and group 2 (9.7 +/- 3.4%, p = 0.013). In conclusion, the present model of minimally invasive infarction coupled with ce-MRI may represent a useful alternative to the open chest model for studies of myocardial infarction and scar development.
用于确定实验性缺血损伤的手术技术是随后心肌瘢痕发展过程中的一个主要因素。我们着手建立一种微创猪心肌梗死模型，使用心脏对比增强磁共振成像（ce-MRI）作为基本诊断工具。27头家猪被随机分为左前降支动脉（LAD）临时闭塞组或永久闭塞组。通过在左前降支动脉直接越过第二对角支处经皮球囊充气实现临时闭塞。闭塞维持30或45分钟，随后再灌注。通过注射凝血酶实现永久闭塞。13只动物在干预期间或干预后因心律失常死亡。14只动物在30分钟缺血（4只动物；第1组）、45分钟缺血（6只动物；第2组）或永久闭塞（4只动物；第3组）后存活。冠状动脉闭塞8周后进行冠状动脉造影和ce-MRI，以记录冠状动脉血流分级和心肌瘢痕组织大小。第1组和第2组所有动物的LAD通畅，TIMI血流正常；第3组动物的LAD完全闭塞。第1组（4.9±4.4%；p = 0.008）和第2组（9.4±2.9%；p = 0.05）左心室纤维化明显低于第3组（14.5±3.9%）。与第1组和第2组相比，第3组缺血区域的壁厚明显更低（分别为2.9±0.3、5.9±0.7和6.1±0.7mm；p = 0.005）。第3组左心室延迟强化程度也明显高于第1组（5.3±5.4%；p = 0.003）和第2组（9.7±3.4%，p = 0.013）。总之，目前这种微创梗死模型结合ce-MRI可能是用于心肌梗死和瘢痕发展研究的开胸模型的一种有用替代方法。
