Diagnosis of recurrent laryngeal nerve palsy after thyroidectomy: a systematic review

Recurrent laryngeal nerve palsy (RLNP) is a recognised possible complication after thyroid surgery. It may present with a variety of symptoms, such as voice change and respiratory symptoms. However, it may remain undetected and the true incidence may be under-reported. The aim of this study was to determine the reported incidence of temporary and permanent palsy after thyroid surgery using different vocal assessment methods. A Medline search was performed. A systematic review was undertaken which included 27 articles and 25,000 patients. The average incidence of temporary RLNP after thyroid operations is 9.8% and the incidence of permanent RLNP is 2.3%. The RLNP rate varied according to the method of examining the larynx and ranged from 26% to 2.3%. Most of the reviewed studies recommend a follow-up period up to 1 year to assess and evaluate RLNP. Our study has identified that different methods are used to diagnose RNLP and that a wide variety of reported RLNP rates exist. We propose establishment of a 'gold standard' for assessing the voice after thyroidectomy to reduce reporting bias.