Giant coronary artery aneurysm with coronary arteriovenous fistula draining into the coronary sinus

A 77-year-old patient suffering from a giant right coronary artery aneurysm with coronary arteriovenous fistula was admitted to our hospital. The fistula could not be documented preoperatively by computed tomography or coronary angiography but was documented intraoperatively by transesophageal echocardiography (TEE). However, TEE was unable to visualize the draining site of the fistula. Direct palpation by the surgeon ultimately confirmed that the fistula was draining into the coronary sinus. The fistula was closed and the volume of the aneurysm reduced by partial resection. The postoperative course of the patient was uneventful. Giant aneurysms occasionally displace cardiac structures. In such cases, combined imaging technologies, including TEE, may be needed for precise assessment of the giant aneurysm and fistula.