Intraoperative factors associated with free flap failure in the head and neck region: a four-year retrospective study of 216 patients and review of the literature.

The aim of this study was to identify intraoperative factors associated with free flap failure. The outcomes of 216 patients (220 flaps) were analyzed retrospectively. A statistical analysis was performed to determine the association of flap failure with the intraoperative factors of prolonged operation time, flap type, vascular pedicle at the recipient site, and use of vasoactive medication. A review of the recent literature was also conducted to identify other intraoperative risk factors. Univariate regression analysis revealed that a prolonged operative time (P=0.013) and the vascular pedicle at the recipient site (P=0.027) were primary risk factors for flap failure. Furthermore, the intraoperative use of papaverine improved the success rate of free flap transfer (P=0.015). Multivariate regression analysis showed that only the application of papaverine remained statistically significant (P=0.011). The results confirmed that the choice of flap type had no influence on free flap survival (P=0.583). In addition, the literature review showed that excessive intraoperative fluid administration is a risk factor for free flap failure. These conclusions may provide microvascular surgeons with information to reduce the failure rate. Also, microvascular surgeons should always consider the details of intraoperative fluid management.