Mycotic superior mesenteric artery aneurysm with impending rupture due to infective endocarditis

A 49-year-old woman with tachycardia was referred to our institution. Transthoracic echocardiography revealed severe mitral regurgitation, and surgery was planned. While awaiting surgery, she developed a fever. Transthoracic echocardiography and transesophageal echocardiography revealed vegetation on the mitral valve leaflet. Blood cultures were positive for <i>Streptococcus anginosus</i>. She was diagnosed with infective endocarditis, and antibiotics were administered. She experienced sudden abdominal pain 26 days after hospitalization. Contrast-enhanced computed tomography scan revealed a mycotic superior mesenteric artery aneurysm with impending rupture without intestinal ischemia, and aneurysm resection was performed. Mitral valve replacement was performed on postoperative day 10, with uneventful postoperative healing.