Ultrastructural Damage to Myocardium and Lung Caused by Ischemic Limb Reperfusion / 日本心臓血管外科学会雑誌

ABSTRACT

Purpose. To investigate deteriorating effects on systemic organs due to actute arterial occlusion of the lower extremities, ultrastructural changes of the heart and lung after temporal occlusion of the abdominal aorta for 24 hours were examined with transmission electron microscopy (TEM). Methods. Fifteen mongrel dogs, weighing 10 to 15kg, underwent temporal occlusion of the infrarenal aorta and lumbar arteries followed by release of occlusion and restoration of circulation 24 hours later. After three-hours' reperfusion, the heart and lungs were excised for pathological evaluation with TEM. Experimental groups were divided into three groups according to the maximum values of CPK (group I, max CPK≤10000; group II, 10000<max CPK≤40000; group III, max CPK>40000 (IU/L)), which had been measured during and after the reperfusion period. Results. TEM examination revealed the following findings in the myocardial tissue: slight cell edema of the myocytes, disruption of the myofibrils, swelling of the mitochondria, interstitial edema, type III bleb formation, cellular edema of endothelial cells and intravascular hemostasis. Pathological findings in the lung tissue included: pulmonary edema, congestive atelectasis, edema of Type I lung epithelial cells and increased neutrophils in the capillary. These findings were significantly remarkable in groups II and III as compared to group I. Conclusions. Elevation of CPK values after the reperfusion period correlated well with the degree of cell damage in the heart and lungs. Free radicals generated during the reperfusion period and their related pathways may play a significant role in the development of cardiac or pulmonary failure after acute arterial occlusion of the lower extremities.