Antibiotic-impregnated grafts for aortic reconstruction.

An infected aorta, or aortic graft, is a challenge to manage. Extra-anatomical bypass followed by resection of the infected aorta has been considered standard practice. Outcomes are far from ideal and anatomical constraints make this impossible at the visceral and thoracic aorta. In situ aortic repair is an alternative and can be accomplished in most cases. Use of this technique has been tempered by concerns of graft durability and reinfection. In vitro and in vivo laboratory experiments have demonstrated antibiotics can be bound to polytetrafluoroethylene and Dacron aortic grafts. In animal models, antibiotic-soaked grafts were resistant to infection when seeded with an intravenous bacteria challenge. Purulent, infected aortic grafts created in animal models by direct bacteria inoculation could be successfully replaced in situ with infection-resistant antibiotic-soaked Dacron grafts. The antibiotic of choice is rifampin, which readily binds to commercially available, off-the-shelf gelatin- or collagen-impregnated Dacron. In humans, rifampin-soaked Dacron has not only been used to reconstruct the aorta in the face of infection, but also in elective aortic reconstruction as a prophylaxis against future infection. Outcomes from case series are difficult to interpret because of the heterogeneous nature of patients presenting with aortic infections. Thirty-day mortality ranges from 7% to 21% and morbidity from 2% to 60%. Amputations are rarely seen in these cases, but are common in extra-anatomical bypass from graft occlusion. Reinfection of the rifampin grafts are seen in 4% to 22% of patients, and 5-year survival is near 50%. In the future, the utility of rifampin-soaked Dacron will have to be tested against the emergence of antibiotic-resistant bacteria. Improvements in alternative conduits, such as cryopreserved aortic grafts, may diminish the use of antibiotic-soaked grafts, but it will remain a useful tool in the vascular surgeon's armamentarium.