Total Endoscopic Thyroidectomy with Intraoperative Laryngeal Nerve Monitoring

Introducing routine intraoperative nerve monitoring in a high-volume endocrine surgery centre: a health technology assessment

We sought to analyse the effect of the introduction of intraoperative nerve monitoring (IONM) in our routine surgical practice and to provide a circumstantial analysis of direct costs of IONM in total thyroidectomy and of indirect costs associated with vocal fold palsy, as centred in the health care system of Italy. We retrospectively compared outcomes of 232 total thyroidectomies performed between November 2017 and October 2019, respectively, before (109 TT-Group A) and after (123 TT-Group B) adopting IONM technology in November 2018. We analysed the costs of IONM per procedure and rate and costs of vocal fold palsy events (temporary and permanent). Overall, there were 61 thyroid cancers (32 in Group B) and 171 multinodular goitres (91 in Group B). We recorded 5 cases of vocal fold palsy (4.6%-4 transient, 1 permanent) in Group A and none in Group B (p = 0.016). IONM consumables cost 219 eur per case. Healthcare and social cost of Vocal fold palsy ranged between 3200 eur (function recovery < 1 month postoperatively) and over 32,000 eur (permanent event). When only direct costs are considered, IONM can hardly be cost effective. In this study, cost of IONM implementation was offset by the absence of complications attributable to recurrent laryngeal nerve dysfunction.

Advantages of intraoperative nerve monitoring in endoscopic thyroidectomy for papillary thyroid carcinoma

BACKGROUND

This study aimed to evaluate the feasibility and effectiveness of intraoperative nerve monitoring (IONM) for reducing the recurrent laryngeal nerve (RLN) injury risk during central compartment lymph node dissection in endoscopic thyroidectomy of papillary thyroid carcinoma (PTC).

METHODS

The prospective cohort consisted of 69 patients diagnosed with PTC undergoing endoscopic thyroidectomy via the areola approach with (N.=42) or without IONM (N.=27). Multiple logistic regression models were used to assess the association between IONM and postoperative temporary vocal cord palsy or number of retrieved lymph nodes.

RESULTS

IONM was a protective factor against temporary RLN injury. IONM use was positively correlated with number of retrieved lymph nodes (β=1.563, P=0.003). After adjustment for operation type, the result remained significant (β=1.581, P<0.001).

CONCLUSIONS

IONM use reduced the risk of temporary vocal cord palsy and increased the number of retrieved lymph nodes in endoscopic thyroidectomy via the areola approach for patients with PTC.

Endoscopic thyroidectomy versus traditional open thyroidectomy for identification of the external branch of the superior laryngeal nerve

AIM

To explore the anatomical features of the external branch of the superior laryngeal nerve (EBSLN) and determine an effective approach for its preservation during endoscopic thyroidectomy (ET).

METHODS

From January 2017 to December 2018, a total of 405 consecutive patients with thyroid disease were retrospectively analyzed. These patients were divided into the ET group and the open thyroidectomy (OT) group according to the surgical approaches. There were 195 cases in the ET group including 43 males and 152 females, and 210 cases in the OT group including 65 males and 145 females. The dissection process of EBSLN, detection rate, distribution of identification methods of the EBSLN and rate of voice change were recorded.

RESULTS

There were 205 EBSLNs detected under direct vision in ET group for a detection rate of 88.0%, while 158 EBSLNs were detected under direct vision in OT group for a detection rate of 58.1%. But with the assistant of intraoperative neuromonitoring (IONM), the number of EBSLNs detected visually reached up to 220 in ET group and 226 in OT group, respectively, for a visual detection rate of 94.4% and 83.1%, respectively. There were significant difference in the rate of direct visual identification, total visual identification with IONM. Stratified risk estimation indicated that the tumor size and location were risk factors for the direct visual dissection of EBSLN. Stratified analysis by tumor size indicated that when tumor diameter was ≤ 4 cm, the incidence of vocal cord fatigue and total vocal changes in ET group was significantly lower than that in OT group.

CONCLUSIONS

Recognition and exposure of the EBSLN can be facilitated by the magnification and focusing function of high-definition endoscopy and the advantage of a 30° variable angle. Full exposure of the sternothyroid-laryngeal triangle and fine dissection along the superior thyroid vessels is beneficial for recognizing the EBSLN.

Extracervical Approaches to Thyroid Surgery: Evolution and Review

Over the last two decades, advances and adaptation of technology have led to a variety of endoscopic thyroidectomy procedures being performed. The drive for extracervical procedures has been predominantly influenced by the desire for improved cosmesis via avoidance of visible scars. Extracervical techniques have shown considerable evolution with approaches that have included transaxillary, breast, postauricular, and transoral routes. There has been a varied evidence base for each of these approaches with regard to technical feasibility, safety, patient satisfaction, and cost-effectiveness. In recent years, robotic-assisted thyroid surgery has gained increased popularity worldwide with the introduction of the da Vinci Robot. Reports of improved postoperative outcomes and patient satisfaction have been in contrast to the financial burden, longer operative time, and increased training required which, to date, have limited widespread application. The aim of this review is to describe the evolution of extracervical procedures including surgical approaches, outcomes, advantages, and disadvantages. Consideration is also given to the future direction of extracervical thyroid surgery with regard to the safety, feasibility, and application of robotic systems.

Methodological Quality of Systematic Reviews of Intraoperative Neuromonitoring in Thyroidectomy: A Systematic Review

Importance

Systematic reviews and meta-analyses are considered the best evidence for clinical decision making. Many reviews of intraoperative neuromonitoring (IONM) in thyroidectomy have conflicting results, owing in large part to methodological quality.

Objective

To assess the methodological quality and the causes of heterogeneous results of systematic reviews that compare routine IONM vs visual identification of the recurrent laryngeal nerve (RLN) in patients undergoing thyroidectomy.

Data Sources

A systematic search was performed of MEDLINE (PubMed), Embase, the Cochrane Library, LILACS (Literatura Latino Americana e do Caribe em Ciências da Saúde), Web of Science, and Google from January 1, 1968, through June 30, 2018. Data were analyzed from July 17 to November 30, 2018.

Study Selection

Studies that mentioned performance of a systematic review/meta-analysis during the search period.

Data Extraction and Synthesis

Data including study characteristics, type of patients, numbers of nerves at risk, and temporary and definitive RLN paralysis by group were extracted. Data about methodological characteristics, type of statistical analysis and summary estimator, endorsement of systematic review/meta-analysis guidelines, heterogeneity, publication bias, funding, conflict of interest, and statistical analysis were also recorded. The methodological quality was measured with the AMSTAR2 (A Measurement Tool to Assess Systematic Reviews) tool by 2 independent evaluators.

Main Outcomes and Measures

Methodological quality.

Results

The search identified 13 systematic reviews that included patients who underwent open or minimally invasive thyroidectomy, second operations, and a mixture of low- and high-risk procedures. The mean compliance with the AMSTAR2 overall criteria was 53% (range, 11%-83%); with critical criteria, 71% (range, 50%-94%). The percentage of nerves at risk from RCTs was 4.8%. The mean (SD) crude rate of definitive RLN paralysis was 0.81% (0.22%; median, 0.75% [range, 0.53%-1.30%]) in the monitoring group and 1.14% (0.56%; median, 0.96% [range, 0.57%-2.56%]) in the control group.

Conclusions and Relevance

A substantial number of systematic reviews of IONM in thyroidectomy have conflicting results, but their mean methodological quality is critically low. Design of a systematic review should comply with methodological standards and recommendations to offer relevant and practical information for decision making.

Protective Effects of Intraoperative Nerve Monitoring (IONM) for Recurrent Laryngeal Nerve Injury in Thyroidectomy: Meta-analysis

Recurrent laryngeal nerve (RLN) injury is an intractable complication of thyroidectomy. Intraoperative nerve monitoring (IONM) was designed to prevent RLN injury. However, the results concerning the protective effect of IONM on RLN injury are still controversial. We searched all eligible databases from 1980 to 2017. Meta-analysis was performed to evaluate the effect of IONM on RLN injury. Sensitivity analysis was also conducted to check the stability of our results. There were 34 studies included in the analysis. Overall analysis found a significant decrease in total injury (RR = 0.68, 95%CI: 0.55 to 0.83), transient injury (RR = 0.71, 95%CI: 0.57 to 0.88), and permanent injury (RD = −0.0026, 95%CI: −0.0039 to −0.0012) with IONM. Subgroup analysis found IONM played a preventive role of total, transient and permanent injury in patients undergoing bilateral thyroidectomy. IONM also reduced the incidence of total and transient injury for malignancy cases. Operations with IONM were associated with fewer total and transient RLN injuries in operation volume < 300 NARs per year and fewer total and permanent RLN injuries in operation volume ≥ 300 NARs per year. The application of IONM could reduce the RLN injury of thyroidectomy. Particularly, we recommend routine IONM for use in bilateral operations and malignancy operations.