Abstract
The role of bacterial infection in the pathogenesis of aorto-enteric fistula was examined by a collective review of the clinical features and bacteriology in 213 patients. The most common presentation, gastrointestinal bleeding, occurred in 49 per cent of patients, although 32 per cent had systemic or local signs of infection as a presenting symptom. Results of intraoperative cultures were available in 115 patients, 33 of whom had two or more isolates. The predominant organisms were Escherichia coli, Staphylococcus aureus, group D Streptococcus and Bacteroides spp. The Gram-positive aerobic cocci predominated in fistulas developing within the first postoperative year which is compatible with a primary infection due to intraoperative contamination with skin flora. The Enterobacteriaceae and anaerobes showed no predilection for early or late occurring fistulas, suggesting that infection in these patients may be secondary to mechanical erosion of the graft through the adjacent duodenum. In either event, the likelihood that the aorto-enteric fistula is complicated by prosthetic infection should be seriously considered by the surgeon in planning the operative procedure.