Preferences for Neurotization of Functioning Free Muscle Transplantation in Long-Standing Facial Paralysis – Global Insights from 107 Experts

BACKGROUND: Dynamic reanimation with functioning free muscle transplantation (FFMT) is the standard of care for long-standing and developmental facial paralysis. Donor nerve selection is pivotal, but no consensus exists on preferred strategies. METHODS: An international, web-based survey was distributed to attending microsurgeons performing FFMT for long-standing facial paralysis. The questionnaire collected demographic data and preferences across ten standardized clinical scenarios. Descriptive statistics summarized responses. RESULTS: A total of 107 experts from 34 countries responded. The gracilis was the preferred donor muscle (92.5%). Donor nerve choice varied with age: for patients <60 years, cross-facial nerve grafts (CFNG) were most common (44.9%), whereas for patients ≥60 years, the masseteric nerve predominated (60.7%). Dual innervation was used by 17-20% of respondents, though optimal configuration varied. In bilateral congenital paralysis, 91.6% favored the masseteric nerve, while unilateral developmental cases showed more evenly distributed preferences among CFNG (35.5%), masseteric (34.6%), and dual innervation (26.2%). Surgeons prioritized either maximal excursion (42.1%) or spontaneous smile (39.3%). Reported CFNG limitations included limited excursion, insufficient axons, and the need for a two-stage procedure. Adjunctive strategies included sensory supercharging (21.5%), electrical stimulation (14.0%), and vascularized nerve grafts (7.5%). CONCLUSIONS: This global survey highlights current preferences in donor nerve selection for FFMT. CFNG is favored in younger patients for spontaneity, while the masseteric nerve is preferred in older individuals for reliability. Dual innervation is increasingly adopted but heterogeneous. These findings underscore the need for comparative outcome studies and consensus-building in free functioning muscle transplantation for facial reanimation.