Descriptive Analytical Study of Recurrent Laryngeal Nerve Palsy in Thyroidectomy- Identified versus Non-Identified Recurrent Laryngeal Nerve

Abstract

BACKGROUND Unilateral or Bilateral Recurrent Laryngeal Nerve (RLN) injuries represent one of the most feared complications after thyroid and parathyroid surgeries. We wanted to estimate the incidence rate of RLN injury in patients undergoing thyroidectomy and compare it when RLN was identified and when not identified during thyroidectomy. METHODS 65 patients admitted for thyroid disorders who underwent thyroidectomy were included. Preoperatively and post operatively, indirect laryngoscopy was done in all patients and patients with immobile vocal cords were excluded from the study. Patients were followed during the 1 st post-op week for any symptoms of RLN injury. Indirect laryngoscopy was done in all the patients on post op day 5 and follow up was done up to 6 months. The patients with vocal cord palsy were subjected to voice therapy. Upon follow up for 6 months, if the patient recovered, it was taken as transient RLN injury and in patients in whom immobility was persistent for more than 6 months it was considered as permanent RLN injury. RESULTS The age of patients ranged from 19 to 75 years, with a mean age of 45.94±12.05 years. Most of the patients who underwent thyroidectomy in our institute were between 30 to 50 years of age. Among the 101 cases, 84 (83.1%) were female and 17 (16.9%) were male with a female to male ratio of 4.9:1. Majority (60.3%) of cases was euthyroid, followed by hypothyroid 23 (22.7). Hyperthyroid state was observed in 17 (16.8%) cases. Benign thyroid disease accounted for 94.1% (n=95) of the patients operated while cancer of the thyroid was noted in 5.9% (n=6). Majority of patients (57.4%) underwent Total Thyroidectomy (TT) followed by Sub-Total Thyroidectomy (STT) (18.8%). Hemi-thyroidectomy was done in 10 patients (9.9%) where only 1 out of 2 nerves was at risk. Total Nerves at risk of injury (TNR) were 192. The rate of recurrent laryngeal nerve injury in the present study was 3.125 for every 100 thyroidectomies done in our institute. During the study period, 5.9% of the patients who underwent thyroidectomy developed RLN palsy wherein 3.125% of the total 192 nerves at risk were injured. CONCLUSIONS Routine post-operative follow-up of patients with indirect laryngoscopy appears to help in early identification of RLN palsy. It appears that identification of RLN during thyroidectomy is likely to reduce the rates of recurrent laryngeal nerve injury especially while doing total thyroidectomy.