Role of Stroboscope in Injury of External Branch of Superior Laryngeal Nerve During Thyroid Surgery.

Abstract

Role of stroboscope in injury of External branch of superior laryngeal nerve during thyroid surgery. Study conducted in a tertiary care hospital. 40 patients were selected and divided into two groups as Group A and B. Benign thyroid swellings were included, excluding preoperative vocal cord pathology by performing videolaryngoscope and videostroboscope. After thyroidectomy procedure stroboscopic fundamental frequency, symmetry, periodicity, glottic closure and mucosal wave pattern were assessed in both the groups and compared. The mean difference in fundamental frequency between pre operative and postoperative in Group A was 37.85 (SD = 33.69) and in Group B was 58.40 (SD = 77.55) with p-value of 0.287. Symmetry of cords in Group A was 90% and asymmetry was 10%, while in Group B symmetry of cords was 75% and asymmetry of 25% with p-value of 0.407. Other parameters like regular periodicity, complete glottic closure, normal mucosal pattern was 95% in Group A and 75% in Group B. Irregular periodicity, incomplete glottis closure, decreased mucosal wave pattern was 5% in Group A and 25% in Group B. Stroboscope is an essential and useful tool in diagnosing EBSLN injury. It is useful in assessing pre operative voice assessment before and after thyroid surgery than a video laryngoscope.