An adult case of giant congenital left atrial wall aneurysm

Congenital left atrial wall aneurysm is a rare disorder that occurs in a wide range of age groups from infancy to adulthood. Here, we present a case of a congenital left atrial wall aneurysm that was detected in a 19-year-old man who was surgically treated. Although the patient was asymptomatic without any pre-existing conditions, chest radiography performed as part of a routine health examination detected abnormalities in the heart. Contrast-enhanced computed tomography revealed a giant aneurysm measuring 72 mm × 56 mm that extended from the posteroinferior wall of the left atrium to the posterior surface of the left ventricle. Transthoracic echocardiography revealed mild mitral regurgitation. The patient was diagnosed as having a congenital left atrial wall aneurysm associated with mild mitral regurgitation. The aneurysm was resected through median sternotomy under cardiopulmonary bypass with cardioplegic arrest. During surgery, no structural abnormalities were noted in the mitral valve. After surgery, the patient was discharged without complications. Neither recurrence of the aneurysm nor exacerbation of mitral regurgitation was observed at 1 year postoperatively. LEARNING OBJECTIVE: A congenital left atrial wall aneurysm is a rare disorder. Rupture of the aneurysm is rare. However, when they are left untreated, there are concerns regarding arrhythmias, heart failure, and systemic embolism. Thus, surgical treatment is recommended. Aneurysms are resected under cardiopulmonary bypass. In cases of aneurysms complicated by moderate or severer mitral regurgitation, mitral valve repair is necessary. The prognosis following surgical treatment is favorable.