Quantitative analysis of the impact of radiotherapy on facial nerve repair with sural nerve grafting after parotid gland surgery.

In this study, we aimed to reveal the long-term impact of radiotherapy on recovery of facial animation function after facial nerve repair using sural nerve grafting in patients undergoing parotid gland surgery. We reviewed the medical records of patients who did or did not undergo radiotherapy following sural nerve graft repair after parotid gland surgery. Facial function metrics, such as House-Brackmann (HB) scale scores and FACEgram measurements, were used to compare facial muscle function between groups. Postoperative radiotherapy was performed in 14 of 21 patients. There was no significant difference regarding successful repair (HB I-III), which was achieved in three of 14 irradiated patients and two of seven non-irradiated patients (p = 0.181). On FACEgram analysis, there was no significant difference in mean smile excursion length between the radiotherapy group (9.16 ± 8.48 mm) and the control group (6.15 ± 4.24 mm) (p = 0.392). There was no significant difference in the mean angle of excursion between the irradiated group (3.59 ± 3.73°) and the non-irradiated group (1.06 ± 5.24°) (p = 0.216). In this study, postoperative radiotherapy did not appear to prevent successful recovery of facial function after sural nerve grafting in parotid gland surgery.