Traditionally, perioperative
bleeding complications were a major concern during orthotopic
liver transplantation, but a tremendous decline in transfusion requirements has been reported over the last decade. In recent years, there has been an increasing awareness towards perioperative thrombotic complications, including liver vessel
thrombosis, and systemic venous and arterial thromboembolic events. Whereas a number of these thrombotic complications were previously categorized as surgical complications, increasing clinical and laboratory evidence suggest a role for the haemostatic system in thrombotic complications occurring during and after
transplantation. High levels of the platelet adhesive
protein von Willebrand factor with low levels of its regulator ADAMTS13, an increased potential to generate
thrombin, and temporary hypofibrinolysis are all indicative of increased haemostatic potential after
transplantation. Clinical evidence for a role of the haemostatic system in post-operative
thromboses includes a higher thrombotic risk in patients with various acquired thrombotic risk factors. Although data on efficacy of
anticoagulant therapy after
liver transplantation are scarce, one study has shown a significant decrease in the risk for late hepatic artery
thrombosis by antithrombotic
therapy with
aspirin. These findings suggest that antihaemostatic
therapy in prevention or treatment of thromboembolic complications after
liver transplantation may be relevant. Studies on efficacy and safety of these interventions are required as many of the thrombotic complications have a pronounced negative impact on graft and patient survival.