Résumé
Objectives: the rate of post-thyroidectomy injury of the external branch of the superior laryngeal nerve (EBSLN) varies between 0.3 and 58%, it is probably underdiagnosed. The aim of this study is to evaluate the incidence of these lesions after thyroidectomy, as well as the risk factors for injury and the recovery rate at six months. Methods: this is a prospective observational study of 21 patients (34 EBSLN at risk) with an indication for partial or total thyroidectomy in the ENT department of the Montpellier University Hospital from 01/05/22 to 05/04/23. The diagnosis of EBSLN paralysis was based on a phoniatric evaluation: pre- and post-operative questionnaires, videostroboscopy, acoustic analyses and aerodynamic measurements; repeated at 6 months in patients with the diagnosis of EBSLN paralysis.Results: the incidence of EBSLN paralysis was 25.7% (9 EBSLN out of 35 operated). A high BMI appears to be a risk factor for EBSLN lesions. Variation in subjective postoperative dysphonia scores is strongly associated with the risk of post-operative EBSLN paralysis. The recovery rate at 6 months was 43%. Conclusions: subjective dysphonia scores such as Voice Handicap Index 10 and EBSLN Voice Impairment Index 5 are significantly altered in postoperative EBSLN palsies. A high BMI value appears to be a risk factor for damage to the EBSLN, which occurs in one in 4 cases following thyroid surgery. It recovers within the first 6 months in 2 out of 5 cases. These results call for further studies to clarify the potential risk factors for EBSLN lesions.