[Infected aortic aneurysms]

Abstract

Infected aortic aneurysms are rare and associated with a high risk of rupture. Diagnosis may sometimes be difficult when the signs of infection are controlled by antibiotic therapy. Blood cultures are negative in 30-50% of cases. Radiologically, saccular and multilobulated aneurysms are typical. The most common microorganisms include Salmonella and Staphylococcus sp. Controversy exists regarding the optimal management of this condition, which includes the route of revascularization (in situ vs. extraanatomic), selection of graft materials (Dacron with or without antimicrobial treatment, expanded polytetrafluoroethylene, autologous vein, or homograft), and indications for stent grafts. Omental transfer appears useful to control local infection. The early mortality rate after open surgery depends on patient condition, aneurysm location, and infective microorganisms, and ranges from 11% to 36%. Late aneurysm-related events are common, occurring in 3% to 14% of patients. Although a lower early mortality rate (around 5%) is reported with stent grafts, late aneurysm-related events are more frequent, reaching 20% at a mean follow-up of 15 months. The prognosis after stent grafting is poor in the presence of persistent infection, with a 1-year survival rate of 39%, although good results can be expected when patients are in stable condition and infection is controlled at the time of implantation.