Surgeon-performed ultrasound analysis of the status of the vocal cords of post-thyroidectomy patients with intraoperative neuromonitoring in a tertiary referral center

Abstract

Objectives: Recurrent laryngeal nerve (RLN) palsy constitutes one of the dreaded complications of thyroid surgery. Sequelae of RLN injury may affect quality of life and can sometimes be life threatening. Pre-, intra-, and post- operative monitoring of the RLN is desirable for safe thyroid surgery. Surgeon-performed transcutaneous laryngeal ultrasound (TLUS) may become a substitute for laryngoscopy in the evaluation of vocal cords after thyroidectomy and may be used for prognostic correlation of intraoperative neurophysiologic monitoring (IONM). In this study, a retrospective cohort of patients who underwent thyroidectomy with monitoring of the RLN by intermittent IONM (I-IONM) was subjected to post-operative ultrasound assessment of vocal cords for the evaluation of RLN integrity. Material and Methods: This was a prospective study of a retrospective cohort in a tertiary care endocrine surgery unit. Fifty-six patients who underwent thyroidectomy with RLN monitoring from March 2017 to March 2019 were analyzed. Patients were analyzed during follow-up either when they arrived at the endocrine surgery outpatient department or through a telephone call. All patients underwent pre-operative laryngoscopy, intraoperative monitoring with I-IONM and Nerve Integrity Monitor 3.0 monitor, and post-operative TLUS evaluation of vocal cords. Results: Of the 56 patients evaluated in this study, 112 vocal cords and 102 nerves at risk were analyzed. The incidence of vocal palsy was 7.84%. The sensitivity of ultrasonography for vocal cord analysis was 85%, specificity was 95.23%, positive predictive value was 85%, and negative predictive value was 95.23% in that series. The vocal cord visualization rate was 93.5%. Conclusion: Surgeon-performed ultrasound may be used to assess RLN integrity in post-thyroidectomy patients to enhance post-operative care.