Free Flap Reconstruction in the Head and Neck Region following Radiotherapy: A Cohort Study Identifying Negative Outcome Predictors

With the increased use of radiotherapy in the treatment of head and neck cancers, free tissue transfer in an irradiated field is now common. Reported outcomes with free tissue transfer reconstructions in irradiated areas are often unclear and contradictory. This is attributable in part to small sample size and heterogeneity in patients and procedures. The goals of this study were, first, to determine the outcome of head and neck reconstructions in an irradiated field using a large retrospective cohort and, second, to identify negative outcome predictors that could potentially be modified to reduce the morbidity in these procedures. Patients undergoing free flap reconstruction in irradiated head and neck regions between July of 2005 and July of 2007 were identified. Charts, including operative and radiotherapy records, were reviewed. Multiple logistic regressions were performed to identify negative outcome predictors. During the study period at the authors' institution, 984 patients underwent head and neck free flap reconstruction. Of these, 137 had free tissue transferred to irradiated fields. Patients received an average radiotherapy dose of 64.5 Gy. The overall flap success rate was 96.4 percent. The postoperative complication rate was 47 percent. There was an overall 22 percent reoperation rate and a 28 percent infection rate. Segmental mandibulectomy, larger flap size, and infection were found to be significant negative outcome predictors. This study confirms that free flap transfer to previously irradiated head and neck areas has a success rate comparable to that of transfer to nonirradiated zones. However, previously irradiated patients have a high risk of complications. Infection, as a modifiable risk factor, should be treated aggressively.