[Clinical characteristics and prognosis of two anastomosis techniques in the treatment of facial nerve defects].

To investigate the characteristics and prognosis of two anastomosis techniques in repairing facial nerve defects. A retrospective analysis was conducted on 30 patients who underwent facial nerve anastomosis（direct or rerouting） for facial nerve defects in our department from January 2012 to December 2021. Among them, 21 were male and 9 were female, with an average age of（37.53±11.33） years, all with unilateral onset. Preoperative House-Brackmann（H-B） facial nerve function grades were Ⅳ in 2 cases, Ⅴ in 9 cases, and Ⅵin 19 cases. The duration of facial paralysis before surgery was within 6 months in 21 cases, 6-12 months in 6 cases, and over 1 year in 3 cases. The causes of facial paralysis included 14 cases of cholesteatoma, 6 cases of facial neurioma, 6 cases of trauma, and 4 cases of middle ear surgery injury. Surgical approaches included 9 cases of the middle cranial fossa approach, 8 cases of labyrinthine-otic approach, 7 cases of mastoid-epitympanum approach, and 6 cases of retroauricular lateral neck approach. All patients were followed up for more than 2 years. The direct anastomosis was performed in 10 cases: 6 cases with defects located in the extratemporal segment and 4 cases in the tympanic segment. Rerouting anastomosis was performed in 20 cases: 11 cases with defects located in the labyrinthine-geniculate ganglion, 4 cases from the internal auditory canal to the geniculate ganglion, 3 cases in the internal auditory canal, and 2 cases in the horizontal-pyramid segment. Postoperative H-B facial nerve grades were Ⅱ in 2 cases, Ⅲ in 20 cases, and Ⅳ in 8 cases, with 73.3%（22/30） of patients achieving H-B grade Ⅲ or better. Both direct and rerouting anastomosis techniques can effectively repair facial nerve defects, with no significant difference in efficacy between the two techniques. Most patients can achieve H-B grade Ⅲ or better facial nerve function recovery. Preoperative facial nerve function and duration of facial paralysis are the main prognostic factors affecting the outcome of facial nerve anastomosis.