Development and validation of VTE prediction model in patients with radical colorectal cancer surgery

Interventions: Gold Standard:Double lower limb venous color ultrasound, double upper limb venous color ultrasound, pulmonary artery CT angiography;Index test:VTE prediction model in patients with radical colorectal cancer surgery Primary outcome(s): Deep vein thromboembolism;Pulmonary artery embolism Study Design: Cross-sectional