Discussion

 

 

Bilateral recurrent laryngeal nerve (RLN) damage with loss of abduction of both vocal cords is a very serious complication of thyroid surgery and usually results in complete airway obstruction, which generally requires immediate tracheal reintubation; a trial of tracheal extubation should be performed in the next few days. When tracheal extubation fails at the second attempt, a tracheotomy is then required. Provided RLN damage is related to trauma but the nerve is not divided, nerve function should return usually within months or at least within one year.

 

RLN damage may be caused by various mechanisms including contusion, stretching, traction, entrapment, and actual transection. The risk of RLN damage is greater during surgery of malignancy and secondary procedures. Neuromonitoring proved to be useful in identifying the RLN but does not reliably predict postoperative function of the nerve (3).

 

When there is any concern during dissection of the RLN, the vocal cord function should be checked immediately after tracheal extubation. In the first case report, this was performed atraumatically with minimal patient discomfort using the Lo Pro Adult GlideScope Video Laryngoscope (LGVL). Bilateral RLN damage was verified (and documented as video clip) and immediate tracheal reintubation was easy to perform. Because of the low risk of failed tracheal reintubation in this patient, we did not consider special tracheal extubation strategies, for example, tracheal extubation over an airway exchange catheter (1)]. For the second tracheal extubation attempt four days later, the same procedure was performed.

 

In the second case report, we verified and documented normal vocal cord function at the operative site in a patient with complete vocal cord palsy at the non-operative site. In the future, we will routinely perform tracheal extubation under videolaryngoscopic view using the LGVL also in other patients with high risk of RLN damage and/or preoperative unilateral vocal cord palsy.

 

The LGVL provided excellent laryngeal exposure during tracheal extubation and evaluation of vocal cord function. This technique may be an alterntive to postoperative flexible endoscopy-assisted laryngoscopy and airway evaluation (6) after thyroid surgery with RLNs at high risk for damage. Furthermore, the LGVL may be used for immediate tracheal reintubation when necessary.

 

 

References