Infected aortic aneurysms: clinical outcome and risk factor analysis

Abstract

Purpose: Infected aortic aneurysms are difficult to treat, and are associated with significant mortality. Hospital survival is poor in patients with severe aortic infection, Salmonella species infection, Staphylococcus aureus infection, aneurysm rupture, and suprarenal aneurysm location. We reviewed the clinical outcome in 46 patients with primary infected aortic aneurysms and identified clinical variables associated with prognosis.

Methods: Data were collected by means of retrospective chart review. Univariate and multivariate logistic regression models were used for risk factor analysis.

Results: Between August 1995 and March 2003, 48 patients with primary infected aortic aneurysms were treated at our hospitals. Two patients with negative culture results were excluded. Of the remaining 46 patients, 35 patients had aortic aneurysms infected with Salmonella species and 11 patients had aortic aneurysms infected with microorganisms other than Salmonella species. There were 20 suprarenal infections and 26 infrarenal infections. Surgical debridement and in situ graft replacement were performed in 35 patients, with an early mortality rate of 11%. The incidence of late prosthetic graft infection was 10%. The 90-day mortality rate in patients operated on was 0% for elective operation and 36% for nonelective operation (P =.006, Fisher exact test). Independent predictors of aneurysm-related death were advanced age, non-Salmonella infection, and no operation.

Conclusion: With timely surgical intervention and prolonged antibiotic treatment, in situ graft replacement provides an excellent outcome in patients with primary infected aortic aneurysms and elective operation. Mortality is still high in patients undergoing urgent operation. Advanced age, non-Salmonella infection, and no operation are major determinants of mortality.