A Systematic Review and Meta-Analysis of Treatment Outcomes Following Tongue Reconstruction With Neurotized Free Flaps.

[BACKGROUND AND OBJECTIVES] The tongue is the most common site of oral malignancy, and surgical treatment may result in impaired feeding, swallowing, and speech. Free tissue transfer is the preferred method for reconstructing complex defects. Evidence remains unclear on whether sensory reinnervation improves function. The objective of this review is to evaluate the outcome of patients undergoing innervated versus noninnervated free flap reconstruction following tongue cancer surgery.

[METHODS] A systematic review was performed to determine the role of sensory neurotization in lingual reconstruction. Only studies with comparative designs were eligible for inclusion. Primary outcome measures included static two-point discrimination (S2PD), pinprick sensation, swallowing, and speech. A meta-analysis was performed using key data analysis to calculate weighted effect sizes for reconstruction with or without neurotization using random-effects models. The statistical heterogeneity was determined using the Higgins' method.

[RESULTS] Nine studies were included which produced 107 reinnervated flaps and 117 non-innervated flaps for pooled analysis. Objective measures of sensation were significant, favoring the reinnervation group for pinprick sensation and S2PD (p < 0.05), with the pooled difference in proportions being 0.25 and -13.88 (0.06-0.45, 95% CI, -26.66 mm to -1.11, 95% CI), respectively. Functional outcome measures revealed significantly improved speech in the reinnervated group (p < 0.05, non-weighted means 74.8 vs. 62.5%).

[CONCLUSIONS] This study found a strong association favoring the sensory neurotization for tongue reconstruction. Higher quality studies are required to further define the role of reinnervation for the restoration of swallow, relative differences between type of free flap selected, and measure changes in patients' quality of life.