Thromboelastography versus viscoelastography for evaluation of coagulopathies in patients after abdominal surgery for cancer

Introduction

The study compared the efficacy of viscoelastography (VG) versus thromboelastography (TEG) for monitoring of perioperative coagulation balance after abdominal surgery for cancer.

Methods

A complete coagulation screen, the activated clotting time (ACT), TEG and VG were performed before surgery and at the end of the operation, and monitoring of LMWH anticoagulation therapy on postoperative days 1, 2, 3, and 7. We tested the hypothesis that the parallel use of standard TEG and VG can fully access the postoperative state of blood coagulation.

Results

The elastic shear modulus of standard MA (Gt) and VGMVA (Gh), which reflect the total clot strength and procoagulatory protein component, was calculated. The difference was an estimate of the platelet component (Gp). There was a 14% increase of standard MA, corresponding to a 48% increase of Gt (P < 0.05) and an 80 to 86% contribution of the calculated Gp to Gt. Using multiple linear regression, all coagulation, TEG and VG variables were used to model perioperative thrombophylia. The results showed that some components of TEG failed to identify hypercoagulation (r < 0.2, P < 0.75). However, three components of the routine coagulation assay, including the bleeding time, prothrombin time and platelet count, could be modeled to show prolonged postoperative hypercoagulability (P < 0.01). We conclude that all components of the VG test reflect postoperative coagulopathies. Serial standard TEG and viscoelastic analysis may reveal the independent contribution of platelets and of procoagulatory proteins to clot strength.

Conclusion

These results suggest that viscoelastic techniques might be useful in the determining the coagulation status in cancer patients perioperatively. Hypercoagulability is not reflected completely by standard coagulation monitoring and TEG, and seems to be predominantly caused by increased platelet reactivity.