The inflammatory response to stent grafting of the thoracic aorta

Aim. The aim of this study was to evaluate the inflammatory reactions in patients with thoracic aortic aneurysms before, during and after stent graft treatment and to relate markers of leukocyte activation to the use of radiographic contrast media. Methods. Blood samples were drawn from 7 patients undergoing elective stent graft treatment for thoracic aneurysms. The samples were analyzed for leukocyte and platelet counts and the concentrations of iohexol (radiographic contrast medium), myeloperoxidase, lactoferrin, neutrophil activating peptide-2 (NAP-2), soluble intercellular adhesion molecule-1, soluble vascular cell adhesion molecule-1 (sVCAM-1), the complement activation products C3bc and the terminal complement complex (TCC). The preoperative results were compared with 10 healthy blood donors of similar age. Results. Preoperatively, the aneurysm patients had significantly elevated concentrations of myeloperoxidase, neopterin and complement activation products compared to controls. Myeloperoxidase and lactoferrin increased after the first contrast dose and peaked at 8 h postoperatively. Platelet counts decreased, while NAP-2, sVCAM-1 and TCC increased from 8 h postoperatively. Conclusion. We conclude that patients with thoracic aneurysms have a low-grade inflammation prior to intervention. Stent graft treatment induces further activation, and markers of endothelial, platelet, and complement activation were increased for several days after the procedure. Radiographic contrast media could be an important contributor to the activation of neutrophil leukocytes.