Saccular aneurysm of the transverse thoracic aorta detected by transesophageal echocardiography.

A patient with a saccular aneurysm of the thoracic aortic arch presented with severe right ventricular failure due to pulmonary artery compression. Contradictory data were derived from computed tomography, pulmonary isotope perfusion scan and cardiac catheterization. Transesophageal echocardiography revealed a saccular aneurysm which compressed the main pulmonary artery and gave access to a fistulous connection to the left pulmonary artery. Surgery confirmed these findings.