Results Of the 97 patients analyzed, total flap necrosis was observed in one patient (1.0%). The incidence rate of flap complications, including flap necrosis and flap dehiscence, was 29.9%. When the time taken to perform one vascular anastomosis, including preparation of the recipient vessel and flap vessel, exceeded 30 min, the incidence rates of flap necrosis (total and partial) (odds ratio, 8.30; 95% confidence interval, 1.91–36.00; P = 0.005) and flap dehiscence (odds ratio, 3.46; 95% confidence interval, 1.05–11.36; P = 0.041) increased significantly.