Preoperative anemia: Predictor of free flap reconstruction complications in head and neck cancer.

Free flap reconstruction has been the mainstay among reconstruction surgeries for head and neck cancer. Intraoperative and postoperative hemoglobin (Hb) levels were both possible risk factors of flap failure and had been discussed widely. However, few investigations of preoperative Hb were seen in the previous study with its effect to flap condition remain uncertain and no conclusions in the literature. Patients who underwent free flap reconstruction after head and neck surgery in our institution between May 2014 and May 2019 were enrolled. The postoperative flap condition was observed carefully, and re-exploration was performed if necessary. We then retrospectively collected patient data with several intraoperative and postoperative indices. A total of 598 patients were enrolled in our study. The total major flap complication rate was 10.6%, with an overall success rate of 89.4%. They were predominantly male (95%), and most of them underwent free flap reconstruction for the first time (91%). A total of 81 (13%) patients received radiotherapy before reconstruction. Among all factors, the preoperative Hb level and free flap type showed significance in univariate and multivariate analyses. A previous history of radiotherapy, body mass index, nutrition status, or poorly controlled diabetes mellitus showed no significant results in either univariate or multivariate analysis. Our study showed that a lower preoperative Hb level affects free flap survival. Meanwhile, preoperative radiotherapy history has no significant influence in either univariate or multivariate analysis.