Mechanisms of recurrent laryngeal nerve injury in endoscopic thyroidectomy for papillary thyroid carcinoma: A large data from China

Abstract

Purpose To investigate the mechanisms of recurrent laryngeal nerve (RLN) injury during endoscopic thyroidectomy via breast approach (ET‐BA) in patients with papillary thyroid carcinoma (PTC). Methods The records of 416 PTC patients who underwent ET‐BA with intraoperative neural monitoring (IONM) from May 2015 to May 2021 in Beijing Friendship Hospital affiliated to Capital Medical University were retrospectively analyzed. Results All patients were women. Mean age was 37.80 (7.87) years. The ET‐BA was performed in 416 patients. Overall incidence of RLN injury was 4.3% (18 patients). Injury was transient in 13 patients (3.1%) and permanent in five (1.2%). Macroscopic physical changes were apparent in the injured nerve in five patients (27.8%) and postoperative hoarseness or cough after drinking water were present in 11 (61.1%). Two RLN injuries occurred during nerve identification at the RLN laryngeal entry point into the surgical field, 15 during early nerve dissection somewhere between the first 0.5 and 2 cm of the nerve's course through the surgical field, and one occurred distal to 2 cm. The percentage of patients with separation, transection, traction and thermal mechanisms of injury was 27.8%, 22.2%, 22.2%, and 16.7%, respectively. The mechanism of injury was unknown in 11.1%. Conclusions RLN injury may still occur during ET‐BA despite endoscopic magnification and early nerve identification even when IONM is used. Separation, transection, and traction injuries were the most frequent causes of injury.

A Prospective Comparative Analysis to Study the Impact on Voice Changes Following Endoscopic Thyroidectomy

“…8 Other mechanisms of nerve injury include transection (discontinuity), traction (stretching of the nerve), constricting (compression of the nerve in an attempt to stop bleeding), and separation injury (blunt or sharp dissection around the nerve). 9 The dissection approach for the preservation of nerves also differs between the 2 techniques. In TOETVA, it begins with the identification and preservation of EBSLN before the division of superior thyroid vessels, followed by the identification of RLNs at the laryngeal entry point (near Berry's ligament) and close to the dividing branches of the inferior thyroid artery, whereas a reverse approach is usually followed in BABA.…”