Vascularized motor nerve to vastus lateralis grafts for restoration of eye closure function in radical parotidectomy: Enhanced reliability in irradiated beds.

Abstract

Nerve grafting is commonly used as a reconstructive strategy to restore facial nerve continuity after radical parotidectomy, aiming to preserve motor end-plate function. However, patients undergoing nerve grafting frequently require adjuvant radiotherapy, and the reported success rates of conventional nerve grafts range from 30% to 60%. We evaluated the outcomes of reconstruction of the upper division of the facial nerve using a vascularized motor nerve to vastus lateralis (MNVL) graft to enhance facial reanimation in the context of preoperative or adjuvant radiotherapy. An exploratory, retrospective analysis of consecutive patients who underwent vascularized or non-vascularized MNVL grafting for reconstruction of the upper division of the facial nerve was conducted. The operative method is discussed, with emphasis on technical refinements including graft and pedicle configuration. The return of MNVL-driven eye closure was the primary outcome assessed. Structured videotaped recordings were used to determine postoperative facial nerve function. Thirty-four patients (n=6 vascularized MNVL and n=28 non-vascularized MNVL) were included in the study (median age, 74 years; median follow-up, 15.0 months). In all cases, coaptation of the MNVL was performed distally to the zygomatic branches innervating orbicularis oculi. Most patients received either preoperative (n=5, 15%) or adjuvant (n=24, 71%) radiotherapy. Most patients with vascularized MNVL showed re-innervation of coapted facial nerve branches (log-rank test, p<0.0001). A higher rate of secondary oculoprotective procedures was required in the non-vascularized cohort (n=10/28 vs. n=1/6). This preliminary study supports the feasibility of motor end-plate re-innervation using vascularized MNVL grafts in patients with head and neck cancer receiving preoperative or adjuvant radiotherapy.