Efficacy of retrograde innervation through the distal stump of the thoracodorsal nerve in single-stage neurovascular latissimus dorsi transfer for facial reanimation: A retrospective analysis of 30 cases

The aim of the study was to analyze the efficacy of retrograde innervation of single-stage free latissimus dorsi (LD) flap for facial reanimation by the distal stump of thoracodorsal nerve (TDN). After the main trunk of TDN was split in half to preserve the function of transverse branch, the proximal stump was coapted with the contralateral facial nerve, and the distal stump was coapted with the ipsilateral masseteric nerve, or vice versa. The length of each nerve stump and the time required for voluntary and spontaneous muscle contraction after surgical treatment were reviewed. Among a total of 30 patients, there was no statistically significant difference in the successful recovery ratio of voluntary smile (antegrade, 86.7%; retrograde, 92.3%; p = 0.323) and of spontaneous smile (antegrade, 61.5%; retrograde, 100.0%; p = 0.079). There was no significant difference in the speed of nerve regeneration of voluntary smile (antegrade, 1.32 cm/month; retrograde, 1.14 cm/month; p = 0.213) and of spontaneous smile (antegrade, 0.91 cm/month; retrograde, 1.09 cm/month, p = 0.120). Within the limitations of the study, it seems that retrograde innervation of neurovascular muscle grafts has the potential to serve as a relevant alternative to other established options of neurovascular muscle transfer, because it provides comparable results in terms of rehabilitation success. (C) 2022 Published by Elsevier Ltd on behalf of European Association for Cranio-Maxillo-Facial Surgery.