Left main coronary artery stenosis associated with extremely long fusiform aneurysm.

Coronary artery aneurysm is defined as coronary dilatation, which exceeds the diameter of normal adjacent segment or the diameter of the patient's largest coronary vessel by 1.5 times [Syed M, Lesch M: Coronary artery aneurysms: a review. Prog Cardiovasc Dis 1997; 40:77-10 84 [1]]. Most studies show an incidence of 1% to 2% [Barettella MB, Bott-Silverman C. Coronary artery aneurysm: an unusual case report and a review of the literature. Cathet Cardiovasc Diagn 1993; 29:57-61 [2]]. Left main coronary aneurysms (LMCA) are even more rare; in a study by involving 22,000 coronary angiograms an occurrence rate of 0.1% has been found [Topaz O, DiSciascio G, Cowley MJ, Goudreau E, Soffer A, Nath A et al. Angiographic features of left main coronary artery aneurysms. Am J Cardiol 1991; 67:1139-1142 [3]]. The majority of patients present with ischemic symptoms secondary to the coexisting atherosclerotic lesions and most of the coronary aneurysms are incidentally diagnosed by coronary angiography. This report details the exceptional case of a 62-year-old patient with "unusually long fusiform" aneurysm of the left main coronary artery associated with critical left main coronary artery distal stenosis involving the ostia of left anterior descending and left circumflex coronary artery. With this case the possible anatomic determinants of the type, location, and mechanism of aneurysm formation were also discussed.