Influence of preoperative radiotherapy on head and neck free-flap reconstruction: Systematic review and meta-analysis.

The effect of preoperative external radiotherapy (XRT) on head and neck free-flap reconstruction is still controversial. In this study, we aimed to determine the impact of preoperative XRT on the outcomes of head and neck microvascular free-flap reconstruction. A systematic review and meta-analysis was conducted in concordance with the Systematic reviews and Meta-Analyses protocol. We searched several databases (PubMed, EMBASE, Web of Science, and Cochrane Library) to find published papers on the topic. The R program was used for data synthesis and statistical heterogeneity evaluation; then, fixed effect or random effect models were used. A total of 37 studies, involving 12 408 patients with 12 668 flaps, were included in this meta-analysis. The overall flap success rate for all studies was 94.4%. Pooled analysis showed that patients with preoperative XRT were significantly associated with an increased risk of total flap failure (odds ratio [OR] = 1.80, 95% confidence interval [CI] = 1.45-2.23, P < .001), partial flap failure (OR = 1.90, 95% CI = 1.07-3.38, P = .029), and postoperative complication rates (OR = 2.22, 95% CI = 1.64-2.72, P < .001). Our study suggests that preoperative XRT is associated with an increased risk of developing free-flap failure and an increased postoperative complication rate.