A “Mickey Mouse” Coronary Anomaly
Aorto-Left Atrial Fistula With Aneurysm
A 58-year-old asymptomatic man with a heart murmur underwent routine Doppler stress echocardiography that detected abnormal high-intensity flow from the aorta to the left atrium. Coronary angiography with a 6-French Amplatz left catheter (Scimed/Boston Scientific) and MEDRAD (MEDRAD Inc) power injections of radiographic contrast revealed a large aorto-left atrial fistula originating anteriorly from the aorta above the sinotubular junction. The fistula coursed caudally and posteriorly, giving off a right coronary artery. The fistula passed behind the aorta and developed into a large bilobed area of aneurysmal dilation resembling Mickey Mouse ears before draining into the left atrium (Figure 1). Contrast-enhanced retrospectively gated spiral acquisition on a 16-detector CT scanner (SOMATOM Sensation 16, Siemens Medical Solutions) confirmed the angiographic findings (Figures 2 and 3⇓). The dimensions of the aneurysm were 6.5 cm × 4.2 cm × 3.9 cm in the transverse, craniocaudal, and anteroposterior planes, respectively. The patient underwent surgical repair consisting of transatrial closure of the fistula tract with oversewing of a pericardial patch, exclusion of the aorto-left atrial fistula and left atrial appendage, as well as saphenous vein bypass grafting of the right coronary artery.