Experimental myocardial infarction in swine by transcatheter coronary artery occlusion with ethanol

Abstract

A technique of staged, closed-chest myocardial infarction using intracoronary ethanol was evaluated in swine. Domestic pigs (n= 10), weighing 40 to 65 kg, were anesthetized and mechanically ventilated. The left anterior descending coronary artery was cannulated with a hollow guidewire (0.035 in) that was advanced to the origin of the first diagonal branch. Absolute ethanol (0.3 to 2.5 mL) was injected through the guidewire. Sixteen procedures were performed in 10 pigs; secondary procedures were attempted in all pigs surviving at least 7 days. Three animals died during the initial procedure. A 4th animal died of ventricular arrhythmias 4 days after the initial procedure. The remaining 6 animals were subject to secondary procedures; 2 of these animals survived. On gross examination, infarcts showed transmural involvement of the anteroseptal region. Evidence of left ventricular aneurysm, with wall thinning and bulging, was noted in 3 animals. Light microscopy confirmed transmural infarction, with healing in various stages. In infarcts less than 24 hours old, marked myocyte edema was found in discrete bundles, predominantly in the subendocardium. In all stages after myocardial infarction, coronary arteries exhibited luminal thrombus with loss of endothelium and, in many cases, medial necrosis. Coronary injection with ethanol is a simple, effective method for experimental myocardial infarction and repeated procedures by this method may be useful in developing an animal model of chronic left ventricular aneurysm