Clinical and Stroboscopic evaluation of vocal cord function before and after thyroid surgery

Abstract

Introduction: Voice change due to injury to the Recurrent Laryngeal nerve and the external branch of the superior laryngeal nerve is an important complication of Thyroid Surgery Objectives: Video Laryngeal Stroboscopy comes in handy for the detection of vocal cord palsies postoperatively that may be missed on routine examination, to know the extent of the pathology. Methods: 100 patients with thyroid swelling who have been evaluated and planned for thyroidectomy in a tertiary care centre between June 2016 to June 2018 were taken as subjects for this prospective observational study. Clinical examination and Video Laryngeal Stroboscopy were done pre operatively and compared to the same on third post-operative day and 1month following surgery. Results: Preoperative Video Laryngeal Stroboscopy was normal in all subjects. 26 out of 100 subjects had subjective postoperative voice change of various degrees. Out of 26 patients, 22 were diagnosed to have Recurrent Laryngeal Nerve palsy and 4 with Superior Laryngeal Nerve palsy .Most common symptoms post-surgery were Voice fatigue in 26% followed by decreased pitch range in 13% and hoarseness in 6% cases. Bowing of vocal cords was seen in 4 subjects (4%), Asymmetry of travelling mucosal wave (slight to severe) in 8 subjects (8%), incomplete glottis closure in 6 subjects (6%). Conclusion: Video Laryngeal Stroboscopy is a useful tool in evaluation of patients with suspected laryngeal paralysis. Paralysis of Superior Laryngeal Nerve, Recurrent Laryngeal Nerve or both results in asymmetric laryngeal vibration that is easily identified by even inexperienced observers using Stroboscopy in an otherwise normal rigid telescopy of larynx

Keywords

• recurrent laryngeal nerve palsy
• stroboscopy
• thyroidectomy