RISK FACTORS AND INCIDENCE OF RECURRENT LARYNGEAL INJURY DURING THYROID SURGERY

Objectives: Paralysis or vocal cord paresis due to iatrogenic recurrent laryngeal nerve damage (RLNI) is one of the major problems in thyroid surgery. Although many procedures have been introduced to prevent nerve damage, the incidence of recurrent laryngeal nerve palsy ranges between 1.5–14%. The purpose of this study is to assess the risk factors for recurrent laryngeal nerve injury during thyroid surgery. Place and Duration: In the Surgical department of Holy Family Hospital, Rawalpindi for two years duration from May 2018 to April 2020. Methods: Patients who underwent thyroid surgery were admitted to the surgical unit were qualified for retrospective review. Factors predisposing to recurrent laryngeal nerve damage, such as pathology of the lesions and type of surgery, and identification of recurrent laryngeal nerve intra-operatively were assessed. All patients underwent pre-operative and postoperative indirect laryngoscopic examinations. Results: 340 patients were included in the study. Transient unilateral problems with the vocal cords occurred in 11 (3.2%) cases and in 1 (0.3%) cases permanent (after Rt hemithyroidectomy). Bilateral problems with the vocal cords occurred in 2 cases (0.58%), but none became permanent. There was a significant increase in recurrent laryngeal nerve damage during secondary surgery (21.7% in secondary vs. 2.8% in primary, p=0.001), total/near total thyroidectomy (7.2% in total vs. 1.9% in subtotal, p=0.024), non-identification of RLN during surgery (7.6% in non- identification vs. 2.6% in identification, p=0.039) and in malignant disease (12.8% in malignant vs. 2.9% in benign, p=0.004). However, there was no significant difference in the frequency of recurrent laryngeal nerve damage in relation to sex (4.1% in men vs 3.8% in women, p = 0.849). Conclusion: The current study showed that thyroid cancer, recurrent goiter surgery, lack of RLN identification and total thyroidectomy were associated with a significantly increased risk of surgical recurrent laryngeal nerve damage. Keywords: Recurrent laryngeal nerve injury, Thyroidectomy, carcinoma of thyroid