The circumstances in which recurrent laryngeal nerve palsy occurs after surgery for benign thyroid disease: a retrospective study of 1026 patients

Objective To evaluate the circumstances in which recurrent laryngeal nerve palsy occurs after thyroid surgery. Methods This study assessed 1026 patients who underwent surgery for benign thyroid disease over a seven-year period in a retrospective, single-centre study. Results With a total of 1835 recurrent laryngeal nerves at risk, there were 38 cases (2.07 per cent) of transient recurrent laryngeal nerve palsy and 8 (0.44 per cent) of permanent recurrent laryngeal nerve palsy. No explanation was found for 10 of the 46 cases of recurrent laryngeal nerve palsy. Among the 38 other cases, the probable causes included poor identification of the recurrent laryngeal nerve during surgery, involuntary resection of the nerve and several other factors. Conclusion Apart from accidental resection of the recurrent laryngeal nerve during thyroid surgery, the causes of post-operative recurrent laryngeal nerve palsy are often unclear and likely multifactorial. Poor identification of the recurrent laryngeal nerve during surgery is still the main cause of post-operative recurrent laryngeal nerve palsy, even when intra-operative neuromonitoring is used.