ORIGINAL ARTICLES   

International Angiology 2000 June;19(2):158-65

Copyright © 2001 EDIZIONI MINERVA MEDICA

language: English

Does in situ replacement of a staphylococcal infected vascular graft with a rifampicin impregnated gelatin sealed Dacron graft reduce the incidence of subsequent infection?

Vicaretti M., Hawthorne W., Ao P. Y., Fletcher J. P.

From the Department of Surgery, University of Sydney and Westmead Hospital, Sydney, Australia

Background. The ­aim of ­this ­study ­was to ­treat meth­i­cil­lin-resist­ant Staphylococcus aure­us (­MRSA) or S. epi­der­mi­dis pros­thet­ic vas­cu­lar ­graft infec­tions by in ­situ replace­ment ­with a rifam­pi­cin bond­ed Gelsoft ­graft.
Methods. Interposition ­grafts ­were ­placed in ­the carot­id ­artery of 56 ­sheep ­and ­the ­graft sur­face direct­ly inoc­u­lat­ed ­with 108 col­o­ny form­ing ­units of ­MRSA or S. epi­der­mi­dis. At ­three ­weeks, ­grafts ­were har­vest­ed ­and ­sheep allo­cat­ed to ­three ­groups. In ­the ­MRSA ­group, ­sheep ­received ­grafts ­soaked in 1.2 mg/ml (12), 10 mg/ml (10) ­and no rifam­pi­cin (7). For S. epi­der­mi­dis, ­sheep ­received ­grafts ­soaked in 1.2 mg/ml (10), 10 mg/ml (9) ­and no rifam­pi­cin (8). There ­were ­two ­deaths, in ­the ­MRSA ­study ­group. Remaining ­sheep ­were eutha­nased ­and ­grafts har­vest­ed ­three ­weeks fol­low­ing regraft­ing. Swabs ­were tak­en to ­assess bac­te­ri­al ­growth in ­the per­i­graft tis­sues, ­and exter­nal ­and inter­nal ­graft sur­fac­es. A 3-5 mm seg­ment of ­graft ­was incu­bat­ed in ­broth medi­um.
Results. For ­MRSA, no sta­tis­ti­cal dif­fer­ence ­between ­the ­groups ­was ­reached ­for ­any of ­the meas­ured param­e­ters. For S. epi­der­mi­dis, a sig­nif­i­cant reduc­tion ­was ­reached ­for ­total infect­ed spec­i­mens in ­the 10 mg/ml ­group com­pared to ­both con­trol (p<0.001) ­and 1.2 mg/ml (p<0.005) ­groups. Graft re-in­fec­tion ­was ­also ­less like­ly to ­occur ­with S. epi­der­mi­dis ­than ­MRSA.
Conclusions. Replacement of S. epi­der­mi­dis infect­ed vas­cu­lar ­grafts ­with 10 mg/ml rifam­pi­cin ­soaked Gelsoft ­graft is effec­tive in reduc­ing sub­se­quent S. epi­der­mi­dis infec­tion. This con­clu­sion can­not be extend­ed to ­MRSA infect­ed vas­cu­lar ­grafts.