Variable relationship of the recurrent laryngeal nerve to the inferior thyroid artery: A meta-analysis and surgical implications.

BACKGROUND: The relationship between the recurrent laryngeal nerve (RLN) and inferior thyroid artery (ITA) is highly variable and traceable back to embryological life.

METHODS: Comprehensive database searches were conducted, followed by judgment of eligibility, assessment, and extraction of data concerning the RLN/ITA relationship. The data were pooled into a meta-analysis and subjected to sex, side-based, geographic origin of study, and study modality subgroup analyses.

RESULTS: Seventy-nine studies (n = 14,269 nerves) reported data on the relationship of the RLN to the ITA. The left versus right-sided comparison revealed stark differences: RLNs were predominantly posterior (62.6% vs 37.0%) and anterior (17.2% vs 37.1%) on the left and right sides, respectively.

CONCLUSION: Symmetry of neurovascular relationships should not be assumed. Extra care should be taken during procedures on the right side, because the nerves are significantly more likely to present in patterns (anterior and between) associated with greater risk of iatrogenic injury. © 2016 Wiley Periodicals, Inc. Head Neck 39: 177-186, 2017.