[Infectious aneurysm rerupture caused by delayed diagnosis: an operative case report].

A 21-year-old febrile woman with sudden onset of headache and semicoma was transferred to our institute. CT and 3D-CT angiography showed subaracnoid hemorrhage and intracranial hemorrhage in the left hemisphere due to a saccular aneurysm at the occluded M2 portion of the middle cerebral artery (MCA). Her present illness started with a toothache and lumber pain 3 weeks earlier. Echocardiography revealed active infective endocarditis. We could have treated her by administering antibiotics, but during a cerebral angiography, she became comatose due to an aneurismal rerupture. Immediately, an emergency operation for aneurismal trapping was performed, but she died 19 days later because of left hemispheric swelling. We report a relatively rare case of infectious aneurysm at the proximal artery and discuss the pitfalls of its diagnosis and treatment. We should educate general physicians about infectious endocarditis because misdiagnosis or delayed diagnosis of infectious aneurysm due to endocarditis results in unpleasant outcomes. We should treat infectious aneurysm at the proximal side artery by first administering antibiotics, and if necessary, subsequent direct surgery of the aneurismal trapping should be performed with a bypass. Unnecessary invasive treatment must be avoided while the disease is in the active infectious stage.