Surgical Pathology of Infected Aortic Aneurysm and Its Clinical Correlation

Pathology of infected aortic aneurysm and its clinical correlation have rarely been reported. Between 1995 and 2005, 48 patients with infected aortic aneurysm underwent in situ graft replacement. Twenty-five patients had a suprarenal and 23 patients had an infrarenal infection. The most common responsible pathogen was nontyphoid Salmonella in 32 patients (67%). During operation, gross pus was present in 26 patients (54%). On pathological examination, aortic atherosclerosis was present in all cases, acute suppurative inflammation was present in 31 patients (65%), and bacterial clumps were present in five patients (10%). Positive culture of the aneurysm wall was present in 14 patients (29%). There were 10 patients with prosthetic graft infection (21%) and 12 patients with aneurysm-related death (25%). Although statistically insignificant, local purulent infection with positive culture of the aneurysm wall, gross pus during operation, or acute suppurative inflammation on pathology tended to be associated with high risk of prosthetic graft infection and aneurysm-related death. In conclusion, infected aortic aneurysm occurred in patients with aortic atherosclerosis. On pathology, acute suppurative inflammation was present in the majority of cases but bacterial clumps were not commonly present. Local purulent infection tended to be associated with high risk of prosthetic graft infection and aneurysm-related death.