Abstract
Mycotic aneurysms of the superior mesenteric artery (SMA) are rare (<1% of mesenteric aneurysms) and often linked to infective endocarditis, carrying high rupture and mortality risks. We report a 53-year-old man with prior mitral and aortic valve replacement for Streptococcus mutans endocarditis, found incidentally to have a 2.1-cm saccular SMA aneurysm on computed tomography angiography. Given its infected appearance and complex branching, open resection with reversed saphenous vein interposition graft was performed. Recovery was uneventful. This case highlights early recognition, imaging, and the role of open repair in infected, anatomically challenging SMA aneurysms.