We suggest monitoring platelet count to detect heparin-induced thrombocytopenia (HIT):At initiation of prophylaxis with LMWH, then once to twice a week from day 4 to day 14 of treatment, followed by once a week for one month if prophylaxis the treatment is continued.At initiation of prophylaxis with UFH, then two to three times a week from day 4 to day 14 of treatment, followed by once a week for one month if prophylaxis is continued.If thrombosis occurs despite prophylaxis with UFH or LMWH.（Evidence level:moderate/Low；Recommendation grade:Strong）

We recommend against routine screening for asymptomatic postoperative DVT.（Evidence level:High；Recommendation grade:weak）

We recommend against routine treatment of postoperative isolated dDVT with therapeutic anticoagulation.（Evidence level:High；Recommendation grade:weak）

When facing postoperative isolated dDVT, we recommend assessing the risk of thrombotic extension (bilateral or multiple DVT (> 1 vein), personal history of VTE, active cancer) and the bleeding risk (related to the patient and procedure) to select the optimal management.（Evidence level:High；Recommendation grade:Strong）

In the absence of risk factors for extension, we suggest starting or continuing anticoagulant thromboprophylaxis for 35 days without ultrasound monitoring.（Evidence level:moderate/Low；Recommendation grade:Strong）

In the presence of risk factors for extension, and if the bleeding risk is low, we suggest starting therapeutic anticoagulation for 6 to 12 weeks.（Evidence level:moderate/Low；Recommendation grade:Strong）

If anticoagulant-based thromboprophylaxis is contraindicated, we suggest against therapeutic-dosing anticoagulation or placement of IVC filter. We suggest performing another CUS on day 7 to look for proximal extension.（Evidence level:moderate/Low；Recommendation grade:weak）

In haemophilia patients, pharmacokinetic-guided treatment should be implemented over real-body weight-guided treatment to assure an optimal perioperative achievement of the prespecified coagulation factor range. (Evidence level:moderate；Recommendation grade:weak)

We recommend that patients with haemophilia, von Willebrand disease and factor X deficiency should be managed with a coordinated, multidisciplinary approach to their care. (Evidence level:Low；Recommendation grade:Strong)

We recommend using frailty testing as an effective tool for predicting postoperative outcomes, especially for assessing the risk of delirium. (Evidence level:Low；Recommendation grade:Strong)