Coagulation, fibrinolysis and inflammation in open surgery for infrarenal abdominal aortic aneurysm

Sammanfattning: Elective repair of infrarenal abdominal aortic aneurysm (AAA) carries a mortality of 4-8% and there is a substantial incidence of serious non-lethal complications. During surgery there is a situation of relative ischaemia and subsequent reperfusion of the lower part of the body. Since most complications may have a thromboembolic aetiology and there are strong evidences for links between inflammation and haemostasis as well as ischaemia/reperfusion and inflammation, increased understanding of disturbances of the haemostatic and inflammatory systems are of importance. Twenty-three patients operated on for AAA according to open standard procedure were studied and compared with an operated control group (OC) undergoing nonvascular surgery of similar magnitude. - In AAA patients prothrombin fragment 1+2 (F1+2), thrombin antithrombin complex (TAT) andsoluble fibrin were elevated preoperatively, increased intraoperatively, especially during reperfusion, and were not normalised one week postoperatively. - Tissue plasminogen activator (tPA) decreased, plasminogen activator inhibitor-1 increased and cross linked fibrin degradation product (D-dimer) had a slight increase in spite of strong coagulation activation intraoperatively. One week postoperatively tPA and D-dimer were significantly increased.- Intraoperatively there were significant increases in the proinflammatory cytokines interleukin-6 (I1-6), monocyte chemoattractant protein - 1 (MCP-1) and the anti-inflammatory interleukin-10 (I1-10). MCP-1 is also a procoagulant and I1-10 an anticoagulant cytokine. Soluble interleukin-2 receptor (SI1-2R) and fibrinogen decreased intraoperatively and were significantly increased one week postoperatively.- Intraoperatively neutrophil L-selectin expression was upregulated, CD11b/CD18 unchanged, neutrophil chemotaxis decreased, and lactoferrin and myeloperoxidase increased. White blood cell and neutrophil cell counts also increased. - In a long-term perspective F1+2, TAT and D-dimer decreased after AAA surgery compared to preoperative levels. However, TAT and D-dimer were still higher than in healthy age matched controls. Conclusions: Preoperatively AAA patients were in a state of coagulation activation. Intraoperatively they were in a strong prothrombotic and proinflammatory state. One week postoperatively the coagulation was still as activated as preoperatively. There were indications for a decline in the coagulation activation in a long-term perspective after AAA surgery. These haemostatic and inflammatory alterations may be due to ischaemia and reperfusion and may contribute to the high complication rate.