Laryngeal Neural Monitoring during Pediatric Thyroid Cancer Surgery-Is Transcartilage Recording a Preferable Method?

Abstract

Simple Summary Comprehensive surgery is advisable in pediatric thyroid cancer. Intraoperative neuromonitoring (IONM) is a useful adjunct to thyroid surgery because it reduces recurrent laryngeal nerve (RLN) palsy risk. Use of the transcartilage (TC) recording method has recently expanded because studies in adult patients indicate that TC electrodes provide more stable electromyography (EMG) signals compared to conventional endotracheal tube (ET) electrodes. This study is the first to report the use of TC-IONM in a pediatric population. In contrast with conventional ET-IONM, TC-IONM avoids the issue of limited accessibility of ET sizes and ET malpositioning or displacement. In pediatric thyroid surgeries, the higher EMG amplitude, superior signal stability and superior signal quality in TC-IONM greatly facilitate a meticulous and extensive RLN dissection that minimizes residual thyroid tissue. In pediatric thyroid cancer, TC-IONM is feasible and effective for monitored thyroidectomy and should be considered the preferable monitoring method. The use of transcartilage (TC) intraoperative neuromonitoring (IONM) in a pediatric population has not been reported. This study evaluated the feasibility and the benefit of using TC-IONM for thyroid cancer surgery in a pediatric population. This retrospective single-center study enrolled 33 pediatric patients who had received an IONM-assisted thyroidectomy. Demographic characteristics, standardized IONM laryngeal examinations and stimulation information (L1-V1-R1-R2-V2-L2) were compared between endotracheal tube (ET) and TC methods. In the 15 cancer patients (30 nerves), TC-IONM provided significant higher electromyography (EMG) amplitude (p < 0.001), signal stability (lower V1/V2 signal correlation, r = 0.955 vs. r = 0.484, p = 0.004), signal quality (higher ratio of V1 or V2 amplitude <500 mu V, 0.0% vs. 43.8%, p = 0.005) and lower R1-R2p change (7.1% vs. 37.5%, p = 0.049) compared to ET-IONM. In the 18 benign patients (28 nerves), TC-IONM provided significantly higher EMG amplitude (p < 0.001), signal stability (r = 0.945 vs. r = 0.746, p = 0.0324) and non-significant higher signal quality and R1-R2p change. This report is the first to discuss the use of TC-IONM in pediatric thyroid surgery. In contrast with ET-IONM, TC-IONM had superior amplitude, stability and quality of EMG signals, which greatly facilitates the meticulous recurrent laryngeal nerve dissection in pediatric thyroidectomies. The TC-IONM method can be considered a feasible, effective and preferable method of monitored thyroidectomy in pediatric thyroid cancer.