ABSTRACT
BACKGROUND: Patient positioning during surgeries for colorectal cancer may represent an unrecognized risk factor for deep venous thrombosis. METHODS: Twelve healthy control patients were positioned supine with knee flexion at 90°. Duplex ultrasound examined common femoral vein (CFV) and proximal femoral vein diameter, peak systolic velocity, and volume flow with hip flexion at 0°, 30°, 60°, and 90°. Data were analyzed using the paired t test. RESULTS: In the CFV, hip flexion to 90° was associated with a significant increase in mean volume flow when compared with hip flexion at 0° (.59 vs .36 L/min; P = .05) and 30° (.59 vs .35 L/min; P = .038). In both the CFV and proximal femoral vein, increased hip flexion was associated with significantly reduced vessel diameter and increased peak systolic velocity. CONCLUSIONS: Intraoperative positioning of the lower extremities represents a modifiable risk factor for deep venous thrombosis. When stirrups are used, hip flexion of 90° maximizes venous drainage from the legs.