Ten-year experience with surgical repair of mycotic aortic aneurysms

Mycotic aneurysm remains a lethal pathologic entity, especially when rupture occurs. It may result from primary aortitis, be induced by septic emboli, or be secondary to an adjacent infection, such as pancreatitis or a psoas muscle abscess. Surgical intervention is the only way to treat such disease. Even when successful repair is achieved by insertion of an interposition in situ graft or by performance of an extra-anatomic bypass, the prognosis is poor. The aim of this study was to present our experience of managing mycotic aortic aneurysms during the past 10 years.

From January 1994 to June 2004, a total of 734 patients with aortic aneurysms underwent surgical repair at our institution. Among these cases, 17 (2.3%) were shown to be mycotic aneurysms of the ascending aorta (n = 1), aortic arch (2), thoracic and thoracoabdominal aorta (3), or abdominal aorta (11); 14 patients (mean age, 58.8 years) were male. Preoperative imaging studies were performed in all patients. Mycotic aortic aneurysms were suspected in 12 of the 17 patients (70.6%) preoperatively, and 4 of these 12 patients were found to have ruptures on imaging. At the time of surgery, 9 of the 17 aneurysms (52.9%) were ruptured. Fifteen patients had an interposition graft inserted after meticulous debridement, 1 underwent an aorto-aortic bypass, and 1 underwent an extra-anatomic (axillo-femoral) bypass. An omentum patch was applied to wrap the graft in 8 of 11 mycotic aortic aneurysms of the abdominal aorta. The most common pathogens were Salmonella spp. (n = 7) and Staphylococcus spp. (4). All patients received antibiotic therapy, according to the culture report, for about 4-6 weeks postoperatively.

In-hospital mortality was 11.8% (n = 2). Another patient died from massive upper gastrointestinal bleeding 6 months after operation because of complications involving an aorto-duodenal fistula, and another died from stomach cancer 6 years after surgery. Long-term follow-up (mean, 37 months; range, 3-111 months) revealed that, at the time of writing, the remaining 13 patients were alive and well, without any recurrence of aneurysm.

Mycotic aneurysm of the aorta is a life-threatening disease, especially when rupture occurs. The high mortality rate is due not only to the high rupture rate, but also to sepsis. When mycotic aortic aneurysm is diagnosed, early surgical intervention is mandatory.