Infective endocarditis associated superior mesenteric artery pseudoaneurysm

Since William Osler first described mycotic aneurysms in the setting of endocarditis in 1885, few pseudoaneurysms (PAs) of the superior mesenteric artery (SMA) have been reported in the literature. We report 2 cases of SMA PA related to infective endocarditis that were managed with open surgery.

Here we report 2 cases of SMA PAs treated with different surgical techniques. A 59-year-old male with a history of intravenous drug use presented with abdominal pain and was found to have Streptococcus viridans endocarditis and an SMA PA. A laparotomy was performed, and proximal and distal control of the SMA PA was obtained. After ensuring that Doppler signals were still present in the distal mesentery and the entirety of the bowel was viable, the SMA was ligated proximal and distal to the PA. The patient recovered uneventfully. The second case is a 35-year-old female who presented with abdominal pain and was found to have Streptococcos gordonii endocarditis and an SMA PA for which the patient was initially observed. After several weeks, the patient's condition deteriorated and the patient underwent open ligation of the SMA, proximal and distal to the PA, with a bypass from the infrarenal abdominal aorta to a distal unnamed SMA branch and resection of 3 ft of ischemic small bowel. The patient continued to have recurrent bowel ischemia over the next several weeks and ultimately died.

SMA PAs associated with infective endocarditis are rare, but carry a high risk of rupture and associated morbidity and mortality. Delay in surgical management may increase this risk.