The Effect of Prior Radiotherapy on Postoperative Complications in Patients Undergoing Free Flap Reconstruction of the Head and Neck

BACKGROUND: Free tissue transfer is standard of care in the reconstruction of large defects in the head and neck. Many patients who undergo free flap reconstruction have had prior head and neck radiotherapy (HNRT). The aim of this study is to compare the surgical outcomes of HNRT versus HNRT naïve patients undergoing free flap reconstruction in a large Australian cohort. METHODS: Data from patients who underwent free flap reconstruction of head and neck defects between January 2017 and December 2020 were extracted from a prospectively collated database at Chris O'Brien Lifehouse (Sydney, Australia). Participants were divided into two groups based on whether or not they had HNRT prior to their free flap procedures. Subgroup analysis was performed comparing patients with mucosal vs. those with cutaneous disease reconstruction. RESULTS: From a total of 525 patients who had undergone free flap reconstruction, 117 (22.3%) had prior HNRT. Prior HNRT was associated with higher rates of flap complications (14.5% vs. 7.8%, p = 0.045), recipient site complications (31.6% vs. 21.1%, p = 0.025), and higher Clavien Dindo Classification (p = 0.040). In the mucosal disease subgroup, prior HNRT was associated with higher rates of flap complications (17.2% vs. 7.8%, p < 0.001). In the cutaneous disease subgroup, there was no difference in complication rates between HNRT naïve and those who had prior HNRT. CONCLUSION: Prior HNRT increases the risk of both flap and recipient-site complications. However, this mainly occurs in patients undergoing reconstruction of mucosal disease.