Abstract: Objective　 To investigate the initial effect of Color Doppler Ultrasound in the donor and recipient vessels of free flaps reconstructing the head and neck defects preoperatively. Methods Eleven patients with head and neck tissue defects requiring free flap transplantation were evaluated by CDUS preoperatively. The blood vessel diameter, peak flow velocity and vessel wall thickness of all the cases in the donor and recipient areas were detected. According to the results of CDUS, the appropriate anastomotic vessels were selected and protected retained during the operation. The flap survival situation was observed postoperatively. Results CDUS provides data on vessel diameter, peak flow velocity and vessel wall thickness. The matching rate of blood vessels in the donor area and the recipient area was 81.82% in 11 cases. All flaps survived. Conclusion Color Doppler Ultrasound can effectively evaluate vascular perfusion before surgery, which is precise, non-invasive, economical and repeatable, and is significant in guiding the design of free flap preoperatively.

Key words: free flap, donor and recipient vessels, Color Doppler ultrasound, head and neck defects