The impact of intraoperative “Nerve Monitoring” in a tertiary referral center for thyroid and parathyroid surgery

Abstract

The most fearsome complication in thyroid surgery is the temporary or definitive recurrent laryngeal nerve (RLN) injury. The aim of our study was to evaluate the impact of intraoperative neuromonitoring (IONM) on postoperative outcomes after thyroid and parathyroid surgery. From October 2014 to February 2016, a total of 80 consecutive patients, with high risk of RLN injuries, underwent thyroid and parathyroid surgery. They were divided in two groups (IONM group and control group), depending on whether neuromonitoring was used or not. We used the Nerve Integrity Monitoring System (NIM)-Response 3.0® (Medtronic Xomed®). The operation time (p = 0.014). and the length of hospital stay (LOS) (p = 0.14) were shorter in the IONM group. Overall mean follow-up was 96.7 ± 14.3 months. The rate of transient RLN palsy was 2.6% in IONM group and 2.5% in the control group (p = not significant). Only one case of definitive RLN injury was reported in control group. No differences were reported between the two groups in terms of temporary or definitive RLN injury. Routine use of IOMN increases the surgery cost, but overall, it leads to long-term cost savings thanks to the reduction of both operating times (106.3 ± 38.7 vs 128.1 ± 39.3, p: 0.01) and LOS (3.2 ± 1.5 vs 3.7 ± 1.5 days, p = 0.14). Anatomical visualization of RLN remains the gold standard in thyroid and parathyroid surgery. Nevertheless, IONM is proved to be a valid help without the ambition to replace surgeon's experience.

Advantages of Intraoperative Neuromonitoring Over Direct Visualization of the Recurrent Laryngeal Nerve During Thyroidectomy

“…A larger sample size would probably make a clinical difference. Despite this limitation and the results in our study, there are authors such as Princi et al who report a reduction in the duration of surgical time from 128.1±39.3 minutes in the control group with only nerve visualization to 106.3±38.7 minutes with the use of IONM (p=0.014) [13]. Fei et al observed a reduction in the time taken to identify RLN in favor of the group where IONM was utilized in the complete endoscopic radical resection of thyroid cancer [14].…”

Electrophysiologic monitoring characteristics of the non-recurrent laryngeal nerve and radiologic evaluation of concurrent vascular anomalies

“…One of the most feared complications of thyroidectomy is RLN injury, with temporary unilateral RLN injury occurring in 1-20% of cases, but usually at a rate of 1-2% in high-volume centers [13]. In a meta-analysis including 25000 cases, it was observed that the rates of transient and permanent RLN palsy varied from 1.4-38.4% (with an average of 9.8%) and from 0-18.6% (with an average of 2.3%), respectively [14].…”

“…They concluded that point A-B comparison combined with the observation of low latency achieved %100 sensitivity and speci city to predict NRILN. The contribution of IONM to the exploration and preservation of the RLN is undeniable, especially in cases with anatomical variations, including NRILN as a rare variation (12,13,14,15). Donatini et al, observed an increased detection rate of NRILN by routine use of IONM during thyroidectomy and reported a decreased rate of nerve injury especially in cases with NRILN [21].…”

Double Recurrent Laryngeal Nerve with Thyroid Carcinoma

“…Additionally, it subjects surgeons to medicolegal is-sues. The likelihood of RLN injury is dependent upon factors such as preoperative diagnosis, surgical procedure, and the surgeon's level of expertise [9]. It is reported that there is a of damage of up to 2% due to the many anatomical variations of the RLN [6].…”