ACUTE INFLAMMATORY REACTION ASSOCIATED WITH ENDOLUMINAL BYPASS GRAFTS

Purpose: Nonspecific inflammatory reactions characterized by local ten derness, fever, and flu-like discomfort have been seen in patients und ergoing endoluminal graft placement in the abdominal aorta or the femo ral arteries. We undertook a study to assess the clinical and laborato ry parameters of this inflammation. Methods: Ten patients with femorop opliteal artery (n = 9) or aortic (n = 1) lesions were treated with En doPro System 1 stent-grafts made of nitinol alloy and covered with a p olyester (Dacron) fabric. Eleven patients implanted with a bare nitino l stent served as the control group. Results: In the stent-graft group , four patients showed clinical signs of acute inflammation manifested by fever and local tenderness. Three of these patients suffered throm bosis of the stent-grafts during the first month of follow-up. Plasma levels of interleukin-lp and interleukin-6 in all stent-graft patients were markedly increased 1 day after intervention (7.3 +/- 2.8 versus 90.2 +/- 34.1 pg/mL and 15.6 +/- 5.8 versus 175.5 +/- 66.3 pg/mL, resp ectively; p < 0.01). This was followed by an increase in fibrinogen (3 .0 +/- 0.2 versus 5.0 +/- 0.2 g/L; p < 0.05) and C-reactive protein (1 4.6 +/- 3.3 versus 77.5 +/- 15.0 mg/L; p < 0.01) at 1 week. No direct correlation between the inflammatory markers and symptoms could be fou nd. In vitro analysis showed that individual components of the stent-g raft did not activate human neutrophils, whereas the intact stent-graf t itself induced a marked neutrophil activation. Conclusions: The comp onent of the self-expanding stent-graft responsible for the nonspecifi c inflammatory reaction was not identified in this study. It is likely that the stent-graft itself or some as yet unrecognized element of th e device other than the Dacron fabric or metal alloy may be a potent i n vivo inducer of cytokine reaction by neutrophils.