A Novel Dual Antibiotic-Bonded Graft for Preventing Vascular Aortic Infection
Ibrahim Aboshady, Aamir Shah, Deborah Vela, Tanya Dvorak, Issam Raad, Kamal G Khalil, L Maximilian Buja. The Texas Heart Institute, Houston, TX; The University of Texas HSC, Houston, TX; M.D. Anderson Cancer Center, Houston, TX; Baylor College of Medicine, Houston, TX
Background: Perioperative infection of an aortic graft is associated with a mortality rate of 10%-30% and an amputation rate >25%. In vitro studies suggest that an antibiotic-impregnated graft could help prevent perioperative graft infection. In a pilot animal study, we bonded aortic grafts with 2 different antibiotics and evaluated their ability to prevent direct perioperative bacterial contamination.
Design: We surgically implanted a 6-mm Vascular Dacron graft in the infrarenal abdominal aorta of 6 Sinclair miniature pigs. Two pigs received grafts bonded with 60 mg/mL solutions of rifampin and minocycline; the other 4 pigs received unbonded grafts. Before implantation, both bonded grafts and 2 of the 4 unbonded grafts were immersed for 15 minutes in a 2-mL solution containing 1 to 2×107 colony-forming units (CFUs)/mL of Staphylococcus aureus (ATCC 29213). Two weeks after graft implantation, the pigs were euthanized, and the grafts were excised for clinical, microbiologic, and histopathologic study.
Results: The 2 S. aureus–treated bonded grafts showed no bacterial growth upon explantation, whereas the 2 S. aureus–treated unbonded grafts had high bacterial counts (6.25×106 and 1.38×107 CFU/graft). The 2 unbonded and untreated grafts had bacterial growth (1.8×103 and 7.27×103 CFU/graft) that presumably reflected accidental perioperative bacterial contamination; Staphylococcus cohnii ssp urealyticus and Staphylococcus chromogenes, but not S. aureus, were isolated. The histopathologic and clinical data confirmed the microbiologic findings. Only pigs that received unbonded grafts had histopathologic evidence of a perigraft abscess.
Conclusions: Bonding aortic grafts with 2 antibiotics appears to be a promising method of reducing direct perioperative bacterial contamination. Further studies are needed to explore this novel graft's ability to combat one of the most feared complications in vascular surgery.
Wednesday, March 21, 2012 1:00 PM
Poster Session VI # 43, Wednesday Afternoon