Abstract
The aim of this review was to identify studies that used thromboelastography (TEG) or rotational thromboelastometry (ROTEM) in microsurgical free flap reconstruction and analyse whether it is a useful adjunct at predicting and identifying thrombotic complications. A search was conducted using the MEDLINE database using the keywords "thromboelastogram", "TEG", "thromboelastography", "free flaps" and "free tissue transfer" using a two-component search with the Boolean operators "OR" and "AND". Eight studies were retrieved using the search criteria. Seven studies met the inclusion criteria, and a further study was found citing several articles from the initial search. Combined, there were 528 patients who underwent 600 free flaps. A total of 10.3% (62) arterial and venous thromboses were reported in the studies, and the combined flap failure rate was 5.2% (26). A total of 67% (4/6) of the studies supported the use of TEG as a predictive tool to detect thromboses, including three retrospective case series and one prospective cohort, which were all statistically significant. There is low-quality evidence (level IV) that a pre-operative TEG and functional fibrinogen to platelet ratio of ≥42 can identify patients at risk of adverse post-operative thrombotic events following free flap surgery; however, further validation is required. Higher quality, standardised prospective or randomised control trials are required to further evaluate the predictive value of TEG. As a pre-operative screening tool, TEG can help to detect pathological changes in coagulation, aid in the transfusion of blood products, target anticoagulation therapy and predict possible adverse events aiding to further reduce patient morbidity.