Relationship between Recurrent Laryngeal Nerve Diameter and Body Mass Index  for Preoperative Prediction of Nerve Size in Thyroidectomy

Abstract

Objective: To study the correlation between recurrent laryngeal nerve diameter and Body Mass Index for preoperative prediction of nerve size in thyroidectomy. Study Design: Cross-sectional study. Place and Duration of Study: ENT Department, Combined Military Hospital, Rawalpindi Pakistan, from Jul 2021 to Jul 2022. Methodology: Patients of either gender aged above 25 and below 80 years who had undergone open thyroidectomies, had malignancies and revision surgery with normal cords were included. Body Mass Index was measured preoperatively, and recurrent laryngeal nerve diameter was measured per operatively after meticulous dissection. RLN was exposed by tracking the inferior thyroid artery and traced along its total course. RLN diameter was measured using Castroviejo caliper. Postoperative examination was performed by an Otolaryngologist with the help of an Anesthesiologist for the assessment of vocal cord functions. Results: Sixty individuals were included in the study. The male-to female ratio was 1:3, the mean age was 45.00±12.22 years, mean height and BMI was 164.55±5.02 cm and 26.59±2.16 kg/m2 respectively. Mean diameter of right and left recurrent laryngeal nerve was 1.46+0.20 mm and 1.71±0.20 mm. Pearson correlation showed a positive and statistically significant relationship between BMI and RLN diameter (r=0.748 right RLN, r=0.812 left RLN, p=0.001). Male candidates had thicker recurrent laryngeal nerve diameters than females on either side. Conclusion: Body Mass Index has a strong positive correlation with diameter of the recurrent laryngeal nerve and can be used as preoperative tool to measure the size of recurrent RLN in thyroid surgeries.

Keywords

• Body Mass Index, Recurrent Laryngeal Nerve, Thyroidectomy