Coagulation status during aortic aneurysm surgery: comparison of thrombelastography with standard tests

A prospective comparison of thrombelastography to standard coagulation tests was undertaken in ten patients undergoing routine, uncomplicated abdominal aortic aneurysm surgery in order to explore potential clinical utility and establish normal patterns of change. Thrombelastograph k values increased (7.1 vs 5.4 min baseline, P < or = .01), and alpha angle (43 vs 52 degrees baseline, P < or = .001) and ma (39 vs 52 mm baseline, P < or = .01) values decreased following graft placement, while r values remained unaffected (6.4 vs 7.5 min baseline, P > .05). Weak correlations were observed between alpha angle and fibrinogen, prothrombin time, and partial thromboplastin time (aPTT), as well as between k and aPTT (0.70 < r < 0.79 for all). Systemic fibrinolysis was suggested by thrombelastography in 25% of samples, although euglobulin lysis times were abnormal in only 5% (chi 2 = 4.80, P < or = .05). Fibrin degradation product detection increased through the fifth postoperative day in all patients. Variations in thrombelastographic parameters and their correlation to standard coagulation tests in patients undergoing uncomplicated abdominal aortic aneurysm repair were documented. In such a setting, no clear advantages to thrombelastography were defined. Further observations will be necessary to establish the role for thrombelastography in the management of patients experiencing clinically significant perioperative coagulation disorders.