Blood coagulation and fibrinolytic response after endovascular stent grafting of thoracic aorta.

OBJECTIVE: Thrombosis is common in aneurysms immediately after stent-grafting, because of exclusion from systemic blood flow. We studied changes in blood coagulation and the fibrinolytic system in patients with thoracic aortic aneurysm or dissection after stent-grafting to examine risk for consumption coagulopathy.
METHODS: Thirty-one thoracic aortic aneurysms were treated with stent-grafting (aneurysm group), and 29 aortic dissections were treated with entry closure with stent-grafting (dissection group). The stent-graft was constructed from a self-expanding Z stent and thin-walled woven polyester fabric. Platelet count, fibrinogen, antithrombin III (AT III), and thrombin-AT III complex were assayed as markers of coagulation. Plasminogen, alpha(2)-plasmin inhibitor, alpha(2)-plasmin inhibitor-plasmin complex, fibrin degradation products fragment E (FDP-E), and fibrin degradation products d-dimer were monitored as markers of fibrinolysis. Blood samples were collected before surgery and on postoperative days 1, 3, 7, and 14.
RESULTS: In both groups platelet count significantly decreased on postoperative days 1 and 3, and increased on postoperative day 14. AT III significantly decreased on postoperative day 1, but recovered after postoperative day 7. FDP-E significantly increased on postoperative day 1 in both groups. There was significant correlation of aneurysm diameter with alpha(2)-plasmin inhibitor-plasmin complex, fibrin degradation products, and d-dimer in the dissection group on postoperative day 1.
CONCLUSIONS: Activation of coagulation and fibrinolysis was observed after stent-grafting to treat thoracic aortic aneurysm and aortic dissection. However, no patients exhibited consumption coagulopathy postoperatively. Therefore we believe there is little risk for consumption coagulopathy after stent-grafting.