A clinical comparative study of real-time recurrent laryngeal nerve moniroring versus conventional exposure during reoperation of thyroid gland

LIU Kun-peng; DAI Wen-jie

doi:10.7504/CJPS.ISSN1005-2208.2016.12.18

Abstract：Objective To compare the difference between real-time recurrent laryngeal nerve(RLN)monitoring and routine exposure, and investigate the clinical value of intraoperative recurrent laryngeal nerve monitoring (IONM) during reoperative thyroid surgery. Methods The clinical data of 118 patients underwent a reoperation for thyroid in Department of Thyroid-breast-cell-transplantation Surgery, the First Affiliated Hospital of Harbin Medical University from May 2014 to May 2016 were analyzed retrospectively. There were 45 patients with normal preoperative laryngoscope result who were reoperated with IONM combined with the naked eye recognition and protection—the nerve monitoring group. The 45 patients with normal preoperative laryngoscope result who were reoperated by using the method of exposing RLN routinely were selected as the control group—routine exposure group via the random number table method and the principle of 1:1. Recognition rate of RLN, confirming the identification time, transient RLN injury, permanent RLN injury, intraoperative blood loss and the amount of postoperative drainage were compared and analyzed. Results In routine exposure group, RLN was identificated successfully in 39 patients, and the confirmation time is (3.4±0.9) min. The remaining 6 patients (13.3%) had not successfully identified the RLN. Through careful dissection during the operation, confirmation time of RLN was prolonged to (16.5 ± 3.2) min. Through the application of the neural monitoring combined with naked eye recognition, the recognition rate of RLN was 100%,and confirmation time was (2.2 ± 0.8) min. Temporary and permanent RLN injury rate in the nerve monitoring group was lower than that in the conventional exposure group:6.7%vs. 22.2%(P<0.05), 0 vs. 2.2%(P>0.05). Intraoperative blood loss and the amount of postoperative drainage in the nerve monitoring group were less than those in the routine exposure group:(12.2±2.9)mL vs.(13.1±1.8)mL(P>0.05),(40.6±2.8)mL vs.(50.8±3.2)mL(P<0.05). Conclusion Compared with the conventional exposure, IONM can speed up the recognition of RLN during reoperation of thyroid gland, improve the recognition rate of RLN,reduce the rate of RLN injury and the amount of postoperative drainage. When the dangerous area of RLN is operated,changes in the amplitude of EMG signals can be found by continuous real-time monitoring to ensure the safety of the operation.