Infected infrarenal aortic aneurysms: when is in situ reconstruction safe?

Twenty-five infected infrarenal aortic aneurysms operated on between 1968 and 1989 were reviewed. They were classified into post-embolic (mycotic) aneurysms (group I), infective aortitis (group II), and infected atherosclerotic aneurysms (group III). Aortoduodenal fistulas were found in eight patients and aortocaval in two. Five patients were operated on in a state of shock, and 12 had preoperative positive blood cultures. Surgical procedures included in situ reconstruction of the aorta (n = 21) and extra-anatomic bypass associated with aneurysmal resection (n = 4). In 19 patients, prostheses were covered with omental flaps, and antibiotics were continued for more than 6 weeks in all patients. In patients who underwent in situ reconstruction, three deaths were related to the initial surgery. All surviving patients were regularly followed up, and none showed any sign of late septic recurrence. In patients who underwent extra-anatomic bypass, two died in the postoperative period, one underwent reoperation 2 years after the initial surgery, and the last patient is doing well. Positive postoperative blood cultures (n = 4) revealed persistent sepsis: two cholecystitis, one spondylitis, and one aortic infection. An exhaustive review of the literature was performed; clinical, bacteriologic, and operative features and results were analyzed; prognostic factors were evaluated; and a practical therapeutic approach was suggested. The importance of preoperative diagnosis, complete resection, debridement of infected tissues, omental flap coverage, and long-term antibiotic therapy with regular computerized tomographic scanning follow-up is stressed.