Three-Dimensional Analysis of Flap Volume Change in Total Tongue Reconstruction: Focus on Reinnervated Dynamic Tongue Reconstruction

In general, flap volume decreases over time and further in the case of a denervated muscle flap. In our institution, dynamic reconstruction, including functional muscle flaps, has been used to aid functional recovery in the past 6 years. This study aimed to determine the effect of volume change of the fat and muscular sections of reconstructed tongue flaps after motor nerve reinnervation in dynamic total tongue reconstruction using 3-dimensional measurement and analysis. A retrospective chart review was performed on 21 patients who underwent total tongue reconstruction using an anterolateral thigh free flap from 2015 to 2020. The fat and muscle volumes of the flap were measured using computed tomography data obtained before surgery (T0), 2 weeks after surgery (T1), and 6 months after surgery (T2) using a 3-dimensional rendering software. Among the 21 patients that underwent tongue reconstruction, 10 underwent dynamic reconstruction, whereas 11 underwent conventional reconstruction using a fasciocutaneous flap. T2 volume compared with T1 was 69.08% in the conventional reconstruction group, and the fat and muscle portions in the dynamic reconstruction group were 77.04% and 69.06%, respectively. No significant difference was noted in the volume change between the 2 groups. After dynamic tongue reconstruction, the muscular volume of the flap had similar volume reduction rate as the fat volume. The dynamic reconstruction was effective not only for functional muscle transfer but also for maintaining the volume of the reconstructed muscle flap.