Vocal Fold Paralysis with Intraoperative Recurrent Laryngeal Nerve Identification versus Non-identification of Recurrent Laryngeal Nerve in Total Thyroidectomy: A Retrospective Cohort Study

Objective: To determine the risk of vocal fold paralysis in patients who underwent total thyroidectomy with and without intraoperative recurrent laryngeal nerve identification. Methods: Study design: Retrospective cohort study Setting: Tertiary military hospital Population: 237 adult patients who underwent total thyroidectomy for benign lesions based on post-operative histopathology operated on by senior third or fourth year residents. Excluded were those who underwent lobectomy with isthmusectomy or reoperation/completion thyroidectomy, had intrathoracic goiters, confirmed malignancies based on post-operative histopathology, or cases wherein the RLN had to be sacrificed due to gross involvement of the nerve caused by malignancy. Results: Group A, wherein intraoperative identification of RLN was done, had a temporary and permanent RLN injury incidence of 2.75% and 0.92% respectively. Group B, wherein intraoperative identification of RLN was not done, had a temporary and permanent RLN injury incidence of 17.19% and 12.5% respectively. Through binary linear regression, the probability of having temporary paralysis increases almost two-fold if the nerve is not identified, and the probability of having permanent paralysis increases by almost nine-fold if the nerve is not identified. Conclusion: We recommend routine intraoperative RLN identification, which has a lower risk for temporary and permanent vocal fold paralysis when compared to non-identification of the RLN. Keywords: cranial nerve injuries/prevention and control, recurrent laryngeal nerve injuries, thyroid neoplasms/surgery, thyroidectomy/adverse effects, vocal cord paralysis/prevention control