P19: THE RELIABILITY OF VENOUS THROMBOEMBOLISM RISK ASSESSMENT TOOLS FOLLOWING FREE FLAP RECONSTRUCTION OF THE LOWER EXTREMITIES

Abstract

Abstract Introduction The incidence of flap failure in lower extremity reconstruction is significantly higher in the lower extremity compared head, neck and breast reconstruction. The commonest cause of flap failure is venous thrombosis. The aim of this study was to assess the reliability of VTE risk assessment tools in patients with open lower extremity fractures and to assess the ability of such tools to identify patients at risk of developing microvascular venous thrombosis following lower extremity free flap reconstruction. Method A single centre retrospective cohort study was conducted between August 2012-August 2019. All patients were risk assessed using the Department of Health (DoH), Modified Caprini and Padua VTE risk assessment tools. Result 58 patients were included, all were at high risk of DVT according to the DoH (mean score± SD, 3.7±0.93), Caprini (10.2±1.64) and Padua (5.4±0.86) risk assessment tools. All patients received thromboprophylaxis, the incidence of clinical deep venous thrombosis was 0%. Intraclass correlation coefficient demonstrated moderate agreement between the Caprini and DoH (0.73, 95% CI 0.54-0.84, p<0.001), the Caprini and Padua (0.52, 95% CI 0.19-0.72, p<0.001) and the DoH and Padua (0.74, 95% CI 0.57-0.85, p<0.001). Microvascular venous thrombosis occurred in 6 patients, resulting in 2 amputations. There were no significant differences in scores between those with and without venous complications. Conclusion Current VTE risk assessment tools do not identify patients at risk of developing venous complications following lower extremity reconstruction. Further prospective studies are required to optimise risk prediction models and thromboprophylaxis use in this cohort. Take-home message Current VTE risk assessment tools do not identify patients at risk of developing microvascular venous thrombosis following lower limb reconstruction.