Primary outcome
DVTs, DVT, intermuscular DVT, thromboses, postoperative DVT, dilated vena cava
DVT
The primary outcome was postoperative DVT, including proximal DVTs such as thromboses in the popliteal vein, femoral vein, or iliac vein, distal DVTs such as thromboses in the anterior tibial vein, posterior tibial vein, or peroneal vein, and intermuscular DVT. DVT was examined using colour Doppler flow imaging at postoperative day 3. The diagnostic criteria of DVT were: (1) dilated vena cava, (2) substantial echo, and (3) intraluminal filling defect. If the symptoms of PE were observed in patients, pulmonary arteriography was applied.