Aneurysm contents as a source of graft infection.

During the past 5 1/2 years, cultures were taken from 68 to 151 surgically treated aortic aneurysms. These cultures were made from nonblood fluids, laminated clot, necrotic areas of the aneurysm wall, or ulcerated atheromatous plaques. Organisms were harvested from seven of the 68 cultures, including Staphylococcus, Escherichia coli, Pseudomonas, and hemolytic Streptococcus. Prophylactic antibiotics were used in all patients; however, the organisms cultured, excepting Streptococcus, were not sensitive to the chosen antibiotics. Three of the seven patients with a positive aneurysm culture died of causes unrelated to infection. Evidence of graft infection has not developed in four surviving patients with positive cultures. Knowledge of the presence of bacteria permitted massive antibiotic therapy based on organism sensitivity.