New Bacteriological Patterns in Primary Infected Aorto-iliac Aneurysms: A Single-centre Experience

Abstract Objectives To assess causative pathogens and surgical outcomes in patients with primary infected aorto-iliac aneurysms at our institution. Design Retrospective study of patients treated at a university hospital between 1992 and 2009. Results We identified 26 patients (median age, 63 years) with primary infected aneurysms on the aorta (descending thoracic, n  = 2; thoraco-abdominal, n  = 3; suprarenal, n  = 2; infrarenal, n  = 15) or iliac arteries ( n  = 4). Among them, 22 were symptomatic, including 13 with ruptured aneurysms. The causative organisms, identified in 25/26 patients, were Campylobacter fetus , n  = 6; Streptococcus pneumoniae , n  = 4; Listeria , n  = 3; Salmonella , n  = 2; Mycobacterium tuberculosis, n  = 2; Staphylococcus aureus , n  = 1; and other, n  = 7. Immune suppression was a feature in 10 (38.4%) patients. Revascularisation was performed in situ in 23 patients (10 allografts, eight grafts, three superficial femoral veins, and 2 stentgrafts) and by extra-anatomic bypass in three patients. Hospital mortality was 23% ( in situ group, 17.4%; extra-anatomic group, 66.7%; χ 2 Yates , P  = 0.24). During follow-up in the 20 survivors (median, 48.5 months), there were two non-infection-related deaths (five and 24 months) and six (30%) vascular complications. Conclusions The bacteriological spectrum of primary infected aorto-iliac aneurysms was wider than previously reported. The availability of new diagnostic tests and increased prevalence of immunosuppression may explain this finding.