Extracardiac aneurysm of the interleaflet triangle above the aortic-mitral curtain due to infective endocarditis of the bicuspid aortic valve

A previously healthy 33-year-old man presented to our hospital with fever, left hemiparalysis, motor aphasia, and clouding of consciousness. Echocardiography revealed vegetation attached to the bicuspid aortic valve as well as an aneurysm originating below the annulus. Head computed tomography showed multiple infarctions. Under the diagnosis of infective endocarditis and perivalvular aneurysm, operation was performed because of the risk of further embolization. Operative findings showed an extracardiac aneurysm of the interleaflet triangle above the aortic-mitral curtain. Because there was no sign of active inflammation, the orifice was closed with an autologous pericardial patch, and the aortic valve was replaced with a mechanical valve. We should be aware of extracardiac aneurysm of the interleaflet triangle when dealing with infective endocarditis, which should be operated as soon as it is found because of the risk for extracardiac aneurysmal rupture.