Successful surgical resection of infective endocarditis involving the left ventricular outflow tract and sigmoid septum

Vegetation in the left ventricular outflow tract (LVOT) due to infective endocarditis (IE) is extremely rare, and no previous reports have described vegetation on the sigmoid septum. We report a rare case of IE with vegetation attached to the sigmoid septum in the LVOT that was successfully managed by surgical resection. An 80-year-old woman was admitted with an acute cerebral infarction and fever. Transesophageal echocardiography revealed highly mobile vegetation attached to the sigmoid septum in the LVOT, and blood cultures were positive for Streptococcus agalactiae. Due to the high risk of further embolization, surgical resection was performed using a transaortic approach. The vegetation was easily removed under direct visualization, and the histopathological findings were consistent with IE. The patient’s postoperative course was uneventful, and antibiotic therapy was continued. Vegetations in the LVOT carry a significant risk of embolic events and potential LVOT obstruction. A transaortic approach allows for safe and effective removal under good visualization. Early surgical intervention should be considered in similar cases.