Comparison of Recurrent Laryngeal Nerve Insult Incidence Post Thyroidectomy for Benign and Malignant Lesions.

Background: Vocal cord paresis or paralysis caused by insult to the recurrent laryngeal nerve is one of the main hazards in thyroid surgery. The frequency of recurrent laryngeal nerve palsy varies between 1.5-20%. Hoarseness is found with unilateral recurrent laryngeal nerve insult (RLNI). Bilateral insult produces dyspnea and life-threatening glottal obstruction. The frequency of insult is more in re-do surgeries, Graves' disease, and thyroid carcinoma operations.

Objective: This study aimed to evaluate the risk factors of RLNI in thyroid surgery for benign or malignant lesions.

Methods: This retrospective investigation recruited 255 participants of both genders, aged 21-59 yrs. (average 39 yrs.), who were scheduled for thyroid surgery at King Hussein Hospital, King Hussein Medical City, Amman, Jordan, from October 2019 to October 2022. An indirect laryngoscopic examination was done for all participants pre and post surgery. Factors of RLNI such as benign or malignant lesions and type of surgery were investigated. Significance was tested with the chi-square test. A P-value of < 0.05 was considered significant.

Results: RLNI was recorded in 25/255 patients (9.8%) following thyroidectomy. Temporary unilateral vocal cord insult was recorded in 17/255 (6.7%) participants out of which it became permanent for 3/255 (1.2%) participants. Bilateral vocal cord insult was recorded in 8/255 (3.1%) participants but did not become permanent for any of them (P < 0.05). A remarkable increase in the frequency of RLNI was found in total/near-total thyroidectomy patients (7/27, 25.9%) compared to patients with bilateral or unilateral subtotal thyroidectomy(18/228, 7.9%; P < 0.05), in malignant lesions (18/105, 17.1%) compared to in benign lesions(7/150, 4.7%; P < 0.05), and in men (9/74, 12.2%) compared to in women(16/181, 8.8%; P < 0.05).

Conclusion: Thyroid carcinoma, total thyroidectomy, and male sex were correlated with a remarkable risk of surgical RLNI.