Intermittent Intraoperative Neural Monitoring Technology in Minimally Invasive Video-Assisted Thyroidectomy: A Preliminary Study

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.

Video-assisted neck surgery (VANS) using a gasless lifting procedure for thyroid and parathyroid diseases: "The VANS method from A to Z"

Purpose

To describe and evaluate our video-assisted neck surgery (VANS) method for thyroid and parathyroid diseases.

Methods

We describe in detail the VANS method for enucleation, lobectomy, total (nearly total) thyroidectomy, and lymph node dissection for malignancy and Graves’ disease. In collaboration with the Japan Society of Endoscopic Surgery (JSES), we evaluated several aspects of this method. The JSES evaluated the method for working-space formation and surgical complications, whereas we examined the learning curve of the surgeons, and the cosmetic satisfaction of the patients and the degree of numbness and pain they experienced. We also asked patients who underwent conventional surgery whether they would have selected VANS had it been available.

Results

The working space for 81.5% of the procedures in Japan was created using the gasless lifting method. The learning curve, considering both blood loss and operating time, decreased after 30 cases. Both factors improved for tumors smaller than 5 cm in diameter. Over 60% of the patients who underwent conventional surgery stated that they would have selected VANS, had it been available. Postoperative pain was worse after conventional surgery than after VANS, but neck numbness after VANS was more frequent than expected.

Conclusions

The VANS method is a feasible, safe, and cost-effective procedure with clear cosmetic advantages over conventional surgery.

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.

Intraoperative neuromonitoring versus visual nerve identification for prevention of recurrent laryngeal nerve injury in adults undergoing thyroid surgery

BACKGROUND

Injuries to the recurrent inferior laryngeal nerve (RILN) remain one of the major post-operative complications after thyroid and parathyroid surgery. Damage to this nerve can result in a temporary or permanent palsy, which is associated with vocal cord paresis or paralysis. Visual identification of the RILN is a common procedure to prevent nerve injury during thyroid and parathyroid surgery. Recently, intraoperative neuromonitoring (IONM) has been introduced in order to facilitate the localisation of the nerves and to prevent their injury during surgery. IONM permits nerve identification using an electrode, where, in order to measure the nerve response, the electric field is converted to an acoustic signal.

OBJECTIVES

To assess the effects of IONM versus visual nerve identification for the prevention of RILN injury in adults undergoing thyroid surgery.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, ICTRP Search Portal and ClinicalTrials.gov. The date of the last search of all databases was 21 August 2018. We did not apply any language restrictions.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing IONM nerve identification plus visual nerve identification versus visual nerve identification alone for prevention of RILN injury in adults undergoing thyroid surgery DATA COLLECTION AND ANALYSIS: Two review authors independently screened titles and abstracts for relevance. One review author carried out screening for inclusion, data extraction and 'Risk of bias' assessment and a second review author checked them. For dichotomous outcomes, we calculated risk ratios (RRs) with 95% confidence intervals (CIs). For continuous outcomes, we calculated mean differences (MDs) with 95% CIs. We assessed trials for certainty of the evidence using the GRADE instrument.

MAIN RESULTS

Five RCTs with 1558 participants (781 participants were randomly assigned to IONM and 777 to visual nerve identification only) met the inclusion criteria; two trials were performed in Poland and one trial each was performed in China, Korea and Turkey. Inclusion and exclusion criteria differed among trials: previous thyroid or parathyroid surgery was an exclusion criterion in three trials. In contrast, this was a specific inclusion criterion in another trial. Three trials had central neck compartment dissection or lateral neck dissection and Graves' disease as exclusion criteria. The mean duration of follow-up ranged from 6 to 12 months. The mean age of participants ranged between 41.7 years and 51.9 years.There was no firm evidence of an advantage or disadvantage comparing IONM with visual nerve identification only for permanent RILN palsy (RR 0.77, 95% CI 0.33 to 1.77; P = 0.54; 4 trials; 2895 nerves at risk; very low-certainty evidence) or transient RILN palsy (RR 0.62, 95% CI 0.35 to 1.08; P = 0.09; 4 trials; 2895 nerves at risk; very low-certainty evidence). None of the trials reported health-related quality of life. Transient hypoparathyroidism as an adverse event was not substantially different between intervention and comparator groups (RR 1.25; 95% CI 0.45 to 3.47; P = 0.66; 2 trials; 286 participants; very low-certainty evidence). Operative time was comparable between IONM and visual nerve monitoring alone (MD 5.5 minutes, 95% CI -0.7 to 11.8; P = 0.08; 3 trials; 1251 participants; very low-certainty evidence). Three of five included trials provided data on all-cause mortality: no deaths were reported. None of the trials reported socioeconomic effects. The evidence reported in this review was mostly of very low certainty, particularly because of risk of bias, a high degree of imprecision due to wide confidence intervals and substantial between-study heterogeneity.

AUTHORS' CONCLUSIONS

Results from this systematic review and meta-analysis indicate that there is currently no conclusive evidence for the superiority or inferiority of IONM over visual nerve identification only on any of the outcomes measured. Well-designed, executed, analysed and reported RCTs with a larger number of participants and longer follow-up, employing the latest IONM technology and applying new surgical techniques are needed.

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.