Novel Method of Double Innervated Free Gracilis Muscle Functional Transfer for Facial Reanimation

Abstract

PURPOSE: Dynamic facial reanimation is the gold standard treatment for a paralyzed face. The use of cross-face nerve graft (CFNG) in combination with the masseteric nerve to innervate free gracilis muscle has been reported in various configurations, with the goal of providing both spontaneity from the CFNG and strong innervation from the masseteric nerve. We report a novel modification to the existing nerve configuration, with presentation of outcomes of our case series. METHODS: A total of 8 patients received free gracilis muscle transfer using the new double innervation method between September 2014 and December 2017. The CFNG, which was performed 9 months prior, was sutured in an end-to-end fashion to the obturator nerve. The ipsilateral masseter nerve was coapted to a nerve graft obtained from extra length of obturator nerve obtained during the harvest of the gracilis muscle. This nerve graft was then sutured in an end-to-side fashion to the sural nerve graft proximal to the end-to-end obturator coaptation (Figure will be provided during presentation). Video analysis was performed on preoperative and all postoperative follow-up. Two independent experienced raters performed Terzis 5 stages classification on the videos. Time to smile with biting down and time to natural smile were also assessed. RESULT: All patients recover smile function with teeth clenching (average, 7.5 months; range, 3–12). Two patients did not recover smile function at 4 and 8 months follow-up, but achieved smile at their 10 and 12 months follow-up. Seven of 8 patients recover spontaneous smile by average of 8.4 months (range, 7–12), with 1 patient having no function after 12 months of follow-up. Average follow-up time was 22 months. Based on the Terzis reanimation grading, 4 patients achieved moderate result, 2 achieved good result, and 2 achieved excellent result. CONCLUSION: Our new novel method of dual gracilis innervation represents a viable technique that does not risk denervation of the gracilis muscle, and provide good spontaneous emotional smile and esthetic symmetry. We hypothesize that placing the masseter nerve at a disadvantage by using the extra nerve graft which requires the signal to go through 3 anastomosis, the CFNG has more time to provide a stronger signal without being taken over by the masseter.