LOCAL TREATMENT OF PROSTHETIC VASCULAR GRAFT INFECTION WITH MULTIVESICULAR LIPOSOME-ENCAPSULATED AMIKACIN

Background. Contaminated surgical fields limit the use of prosthetic v ascular grafts. We studied the efficacy of sustained-release amikacin applied locally to contaminated grafts in the prevention of infectious complications. Materials and methods. Thirty-one New Zealand white ra bbits underwent placement of a polytetrafluoroethylene (PTFE) interpos ition graft in a 1-cm segment of the descending aorta. The surgical fi eld was infected with application of 10(5) to 10(8) Staphylococcus aur eus organisms suspended in normal saline solution. Nineteen rabbits un derwent contaminated aortic graft placement without treatment. Twelve rabbits were treated with local application of 2.5 ml of amikacin enca psulated in lipid particle-based sustained-release dosage form. Rabbit s were observed for 2 weeks and then evaluated for the presence of gra ft infection. Results. Seventy-five percent of the treated rabbits sur vived without evidence of graft infection or systemic sepsis versus 37 % in the untreated group (P < 0.04). Cultures verified the absence of organisms in all surviving rabbits without clinical infection. Conclus ions. Sustained-release lipid particle-encapsulated amikacin applied t o contaminated PTFE grafts increased survival and decreased postoperat ive graft infections. Adjunctive use of local, delayed-release antibio tics in contaminated vascular beds may allow wider clinical use of pro sthetic grafts. (C) 1998 Academic Press.