Bridging anticoagulation (usually with low molecular weight heparin) is not required except in patients deemed to be at high risk on peri‐operative thromboembolism (e.g. with recent (< 3 months and especially 1 month) history of pulmonary embolism or deep venous thrombosis; severe thrombophilia (deficiency or protein C, protein S or antithrombin); antiphospholipid antibodies; or active cancer associated with a high thromboembolism risk) [120]. The gene discussed is PROS1; the disease is Rare hereditary thrombophilia.