Abstract: Objective: To explore the feasibility, effectiveness, and clinical value of Ren anastomosis in oral and maxillofacial defects repair with free flaps. Methods: Between July 2017 and December 2018, 116 patients (118 flaps), including 97 males and 19 females, aged 34-71 years old, underwent free skin flap repair for oral and maxillofacial defects in departments of oral and maxillofacial surgery of Tongji hospital and Union hospital, Tongji Medical College, Huazhong University of Science and Technology. They were divided into two groups according to the arterial anastomosis method, Ren anastomosis group (50 flaps) and conventional end to end anastomosis group (68 flaps). And the venous anastomosis method of the both groups was conventional end to end or end to side anastomosis. Results: The average time of arterial anastomosis of Ren anastomosis was obviously shorter than that of control group [(5.6±2.1) minutes and (13.7±4.2) minutes]. In totally, one case of arterial crisis and one case of venous crisis following with the flap necrosis occured in Ren anastomosis group; and in the control group, one flap failed to rescue after arterial crisis and 3 flaps developed venous crisis. Conclusion: Ren vascular anastomosis method obviously reduces the operation time and simplifies operation steps compared to conventional vascular anastomosis. It was recommonded to use Ren anastomosis in the repair of oral and maxillofacial defects.

Key words: Ren anastomosis, microsurgery, free flap, artery anastomosis, oral and maxillofacial defects