Korean J Otorhinolaryngol-Head Neck Surg.  2020 Dec;63(12):594-602. 10.3342/kjorl-hns.2020.00598.

Risk Factors for Iatrogenic Vocal Fold Palsy during Thyroid Surgery: A Single Institutional Experience Over 10 Years

• Jeong YW
• Han YS
• Lee HS
• Kim SW
• Lee KD

• KMID: 2511307
• DOI: http://doi.org/10.3342/kjorl-hns.2020.00598

Abstract

Background and Objectives
Recurrent laryngeal nerve (RLN) palsy is a critical complication of thyroid surgery. The aim of this study was to investigate the incidence of iatrogenic temporary or permanent RLN palsy and to determine the surgeon’s experience factor for iatrogenic RLN palsy.
Subjects and Method
We retrospectively reviewed 3404 patients, who underwent thyroidectomy between 2010 and 2019, to identify the surgeon’s experience factor for iatrogenic RLN palsy. Information about patient demographics, surgeon factor, whether or not intraoperative neuromonitoring (IONM) were used, and the postoperative status of RLN were collected. The incidence of RLN injury was analyzed according to the surgeon experience, surgery for thyroid cancer, effect of IONM and the extent of surgery.
Results
A total of 4479 RLNs were at risk in 3094 thyroidectomies in this study. There were 34 (1.10%) postoperative vocal cord palsy (VCP) cases after thyroidectomy. All patients with RLN palsy showed a unilateral type. VCP was temporary in 26 (0.84%) cases and permanent in 8 (0.26%) cases. Using the nerve at risk (NAR) method, we found that there were 34 NAR palsy out of the total (4479) NAR (0.76%), 26 NAR temporary palsy (0.58%), and 8 NAR permanent palsy (0.18%). The mean recovery time after temporary VCP ranged between 2-180 days (50.6 days in average). The incidence of permanent RLN injury was higher in surgery conducted by less experienced surgeon (1.71% in less experienced vs. 0.05% in experienced surgeon, odds ratio 35.991, p<0.001). Application of IONM had no impact on incidence of iatrogenic RLN injury.
Conclusion
The present study demonstrated that less experienced surgeon is associated with an increased risk of iatrogenic permanent RLN palsy after thyroidectomy.

Keyword

Intraoperative neuromonitoring; Recurrent laryngeal nerve injury; Thyroidectomy; Vocal cord paralysis