ENDOVASCULAR STENT INFECTION WITH DELAYED BACTERIAL CHALLENGE

BACKGROUND: Reports of endovascular stent infection have recently been described, The purpose of this study was to determine if intravascula r metallic stents in a swine model could become infected following a b acterial challenge given remote from the time of stent placement. METH ODS: Balloon expandable metallic stents (Palmaz) were implanted in the iliac arteries of 14 swine, An angioplasty, without stent placement, was also performed in the contralateral iliac artery, An intravenous b acterial challenge with Staphylococcus aureus was given 4 weeks after stent placement. Euthanasia was performed 72 hours after the bacterial challenge. At the time of euthanasia, the iliac artery/stent complex and the contralateral angioplastied iliac artery were harvested and se nt for microbiologic and pathologic analysis. RESULTS: Seven of the 14 stent/artery complexes were culture positive for S aureus whereas onl y one of the 14 angioplastied arteries was positive for S aureus (P = 0.03). On histologic examination, 6 of the 14 stent/artery complexes h ad evidence of acute inflammatory changes in the arterial wall. This c ompares with only 1 of 14 angioplastied arteries having evidence of in flammatory infiltrate in the arterial wall (P = 0.07). All 6 of the st ent/artery complexes with inflammatory infiltrate were culture positiv e. CONCLUSION: In the swine model, intravascular metallic stents have the potential to become infected when a bacterial challenge is given 4 weeks after stent placement, Further studies evaluating the incidence of stent infections in humans are needed. (C) 1997 by Excerpta Medica , Inc.