Mycotic aneurysm complicating staphylococcal endocarditis

To emphasize the role of noninvasive diagnostic investigative methods and their importance in early detection of mycotic aneurysm related to staphylococcal endocarditis, and of monitoring therapy or identifying complications.

Two patients with mycotic aneurysm that developed as complications of staphylococcal endocarditis are presented. The first patient had mesenteric artery mycotic aneurysm and presented with sudden rupture one month after initial diagnosis of mitral valve infective endocarditis and completion of a full course of antimicrobial therapy. The second patient had multiple cerebral mycotic microaneurysms and presented with hemorrhagic cerebral embolization from aortic valve infective endocarditis.

The first patient died because of ischemic cerebral edema 48 h after rupture of the mesenteric artery mycotic aneurysm and massive hemoperitoneum, which was treated surgically with distal ileal resection and ileostomy. The second patient was alive two years after prolonged antimicrobial therapy and aortic replacement to treat moderate aortic regurgitation and progressive left ventricular enlargement.

Mycotic aneurysm is a rare complication of infective endocarditis but has a high mortality rate because of its early or late potential catastrophic rupture. Diagnosis by noninvasive diagnostic imaging techniques of mycotic aneurysm before rupture would be beneficial for its treatment.