Age-related outcomes of facial reanimation surgery using gracilis free functional muscle transfer innervated by the masseteric nerve: A retrospective cohort study.

BACKGROUND: The free functional muscle gracilis transfer is an established approach in facial reanimation surgery; however, the significance of its neurotization and the patient's age is still inconclusive. Several donor nerves are available for facial reanimation using the free functional gracilis muscle transfer. OBJECTIVE: This retrospective cohort study investigates whether the masseteric nerve is an equally reliable donor nerve in both older and younger patients. METHODS: We included 46 patients (13-71 years, male and female) who underwent nerve-to-masseter (NTM)-driven free functional muscle transfer (FFMT) between January 2008 and December 2019. Patients were distributed into three cohorts according to their age at surgery. We assessed the facial symmetry before and after surgery using the pupillo-modiolar angle. Commissure height and excursion deviation were measured with the Emotrics software. Patient-reported outcome measurements were taken using the Facial Clinimetric Examination (FaCE) scale. RESULTS: All patients had successful flap innervation, except for one patient in the middle-aged cohort (31-51 years). The postoperative facial symmetry at rest, smiling, and laughing was analyzed with the pupillo-modiolar angle and the Emotrics software and showed similar results between all cohorts. The FaCE scale showed similar scores for the middle-aged (31-51 years) cohort and the senior cohort (52-71 years). The social function score in the senior cohort was higher than in the middle-aged cohort, without statistical significance. One patient in the middle-aged (31-51 years) cohort and the senior cohort (52-71 years), respectively, underwent emergency revision due to impaired flap perfusion and could be salvaged. CONCLUSIONS: NTM-driven FFMT for facial reanimation is a safe and reliable procedure across all age groups of patients.

Age-related outcome of facial reanimation surgery using cross face nerve graft and gracilis free functional muscle transfer-A retrospective cohort study.

BACKGROUND: Free functional muscle transfer has become the criterion standard for the treatment of long-standing flaccid facial paralysis. Clinical experience suggests that a two-stage approach using a cross-face nerve graft (CFNG) as a donor nerve for free functional muscle transfers (FFMT) is less successful in older patients when compared to the pediatric population. However, clear data and scientific evidence are still rare. This study examines the age-related outcome of CFNG-driven FFMT. METHODS: Twenty-eight patients with a mean age of 20.73 years (ranging 5-51 years) who received two-stage facial reanimation with CFNG-driven gracilis FFMT at our institution from 1998 to 2019 were included. The ipsilateral sural nerve was used as CFNG. After 12 months, the ipsilateral gracilis muscle was used as FFMT. Patients were distributed equally into three cohorts according to their age. We assessed facial symmetry before and after facial reanimation measuring the angle between the interpupillary and the intermodiolar line (pupillo-modiolar angle). Additionally, the commissure height was measured using the Emotrics software. RESULTS: The mean follow-up of the pediatric, young adults and the middle-aged cohort was 29.5 ± 7.3, 24.9 ± 6.3, and 25.5 ± 12.4 months, respectively. One patient suffered flap loss due to flap ischemia. Four patients suffered insufficient innervation of the FFMT. Otherwise no major complication occurred. The likelihood of successful innervation of the FFMT was significantly higher in patients younger than 31 years (100% vs. 50%; p = .003). Smiling facial symmetry (pupillo-modiolar angle) significantly improved in the pediatric cohort (5-16 years; 8.68° ± 0.69° to 1.48° ± 0.67°; p < .001) and the young adults' cohort (17-30 years; 11.55° ± 1.95° to 4.62° ± 1.08°; p = .005), but improved only slightly in the middle-aged cohort (31-51 years; 11.77° ± 1.16° to 9.4° ± 1.8° p = .27). The postoperative smiling symmetry showed a significant correlation with increasing age (r = .62, p < .001). The smiling commissure height deviation significantly improved in the pediatric cohort (5-16 years; 6.5-2.3 mm; p = .006) and the postoperative result was significantly better than the middle-aged group (31-51 years; 2.3 vs. 7.5 mm; p = .02). CONCLUSIONS: The outcome of CFNG-driven gracilis FFMT is age-related. Static as well as dynamic facial symmetry after two-stage facial reanimation was best in the pediatric and young adult population. For older patients, other approaches like the nerve-to-masseter-driven FFMT should be considered.