Alterations in coagulation following major liver resection

Abstract

SummaryThe international normalised ratio is frequently raised in patients who have undergone major liver resection, and is assumed to represent a potential bleeding risk. However, these patients have an increased risk of venous thromboembolic events, despite conventional coagulation tests indicating hypocoagulability. This prospective, observational study of patients undergoing major hepatic resection analysed the serial changes in coagulation in the early postoperative period. Thrombin generation parameters and viscoelastic tests of coagulation (thromboelastometry) remained within normal ranges throughout the study period. Levels of the procoagulant factors II, V, VII and X initially fell, but V and X returned to or exceeded normal range by postoperative day five. Levels of factor VIII and Von Willebrand factor were significantly elevated from postoperative day one (p < 0.01). Levels of the anticoagulants, protein C and antithrombin remained significantly depressed on postoperative day five (p = 0.01). Overall, the imbalance between pro-and anticoagulant factors suggested a prothrombotic environment in the early postoperative period.

Bleeding risk assessment in elective cardiac surgery

“…This allowed us to assess not only pre-existing platelet dysfunction (for example, due to pre-operative antiplatelet therapy [9-11]), but also to assess platelet dysfunction induced during CPB [4,12], and induced by protamine [8]. Accordingly, impedance aggregometry results obtained after protamine administration demonstrated the best correlation with postoperative chest tube drainage in our study [1].…”

“…The imbalance of pro-to anti-coagulants, with an excess of factor VIII and low levels of antithrombin and protein C, means these patients are potentially prothrombotic and should not be considered 'auto-anticoagulated' solely because the INR is elevated. [1]. The authors measured platelet function at three time points; before induction of anaesthesia; after removal of the aortic clamp; and 5-10 min after protamine sulphate administration, which allowed measurement of platelet haemostatic function in case of bleeding and precise timing and dosing of antiplatelet therapy.…”

“…We appreciate Lanc e's interest in our paper on bleeding risk-assessment in patients undergoing elective cardiac surgery [1]. Our prospective, observational study was designed to compare both impedance aggregometry methods and their predictive value for bleeding and transfusion at different timepoints during elective cardiac surgery, but not to assess the influence of platelet count and haemoglobin concentration on these methods since the dependency of impedance aggregometry results on platelet count is already well known and described in the literature [2][3][4].…”

Comment on: Early recovery pathway for hepatectomy: data-driven liver resection care and recovery

“…This is mainly due to reduced production of the endogenous anticoagulants (protein C, protein S and antithrombin), plasminogen, tissue factor pathway inhibitor (TFPI), together with increased levels of factor VIII, von Willebrand factor (vWF), soluble P-selectin and plasminogen activator inhibitor-1 (PAI-1), none of them reflected by PT (8). Recent evidence clearly indicates a direct relationship between the magnitude of hepatectomy and postoperative rates of VTE.…”

Coagulation following major liver resection - a reply

“…Thrombin generation using platelet-rich plasma in patients with chronic liver disease is highly dependent on platelet count [4]. This is relevant when interpreting Mallett et al's study, since the patients had normal platelet counts postoperatively [1], which may have affected the results of the thrombin generation tests.…”