Ischaemia and reperfusion during open abdominal aortic aneurysm surgery induce extensive thrombin generation and activity

Objectives: does open surgery for abdominal aortic aneurysm (AAA) influence coagulation? Methods: in 23 patients operated on for AAA, cubital blood was sampled pre-, intra- and postoperatively. Femoral blood was also sampled intraoperatively. Results: preoperatively, prothrombin fragment 1 + 2 (F1 + 2), thrombin-antithrombin complex (TAT) and soluble fibrin (SF) were elevated in AAA patients. During aortic clamping all parameters increased significantly in cubital blood (p<0.01) as well as in femoral blood (p<0.001) and after aortic declamping F1+2 and TAT increased further. F1+2, TAT and SF were significantly higher in femoral than cubital blood. postoperatively F1+2 and TAT returned to preoperative values, while SF still had a significantly higher level than preoperatively (p<0.001). Blood loss showed covariation with F1+2 increase in femoral blood after aortic declamping (p<0.05). Conclusions: these data indicate that the coagulation system was strongly activated by the occurrence of an AAA. During AAA surgery a further extensive activation was seen. The activity was still high, but on decline, one week postoperatively. Ischaemia and reperfusion of the lower part of the body were the major stimuli for thrombin generation and activity.