B. C. Brajcich1, C. R. McHenry1,2 1Case Western Reserve University School Of Medicine,Cleveland, OH, USA 2MetroHealth Medical Center,Department Of Surgery,Cleveland, OH, USA
Introduction:
Damage to the recurrent laryngeal nerve during thyroidectomy can lead to vocal cord paralysis, resulting in hoarseness and respiratory distress. Prior studies have demonstrated mixed results regarding the role of intraoperative nerve monitoring (IONM) in preventing recurrent laryngeal nerve injury. The purpose of this study was to examine the effect of IONM on recurrent laryngeal nerve injury during thyroidectomy.
Methods:
A retrospective cohort study was performed on patients undergoing thyroidectomy performed by a single surgeon over a 6-year period beginning in 2009 (n=627). Routine intraoperative monitoring was implemented in 2012 and was used in a cohort of 315 consecutive patients. The recurrent laryngeal nerve was routinely identified and traced through its entire course in all patients and the IONM was used solely to confirm the functional integrity of the nerve throughout its dissection. The rate of recurrent laryngeal nerve injury was compared to a cohort of 312 consecutive patients who underwent thyroidectomy during the 3-year period immediately prior to implementation of IONM. Secondary analysis was performed to determine if there was a relationship between nerve injury and patient age, sex, substernal thyroid extension, central neck dissection, re-operative neck surgery, nodule size, thyroid gland weight, or pathology. Subgroup analysis was performed for patients with malignant pathology, substernal thyroid extension, re-operative neck surgery, and central neck dissection.
Results:
Of the 627 patients who underwent thyroidectomy, 7 (1.1 %) had a recurrent laryngeal nerve injury. There was no correlation between the use of the IONM and recurrent laryngeal nerve injury. Of the 531 nerves at risk in the cohort with IONM, 4 (0.75 %) were injured compared to 3 injuries (0.58 %) among the 517 nerves at risk in the cohort without IONM (p>0.05). No secondary measures demonstrated a statistically significant relationship with recurrent laryngeal nerve injury. Subgroup analysis did not show any relationship between IONM and nerve injury.
Conclusion:
IONM had no impact on the rate of recurrent laryngeal nerve injury during thyroidectomy. Further studies with larger sample sizes are necessary to confirm our findings, especially in specific high-risk subgroups.