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

Does the Use of Intraoperative Neuromonitoring during Thyroid and Parathyroid Surgery Reduce the Incidence of Recurrent Laryngeal Nerve Injuries? A Systematic Review and Meta-Analysis

Injury to the recurrent laryngeal nerve (RLN) can be a devastating complication of thyroid and parathyroid surgery. Intraoperative neuromonitoring (IONM) has been proposed as a method to reduce the number of RLN injuries but the data are inconsistent. We performed a meta-analysis to critically assess the data. After applying inclusion and exclusion criteria, 60 studies, including five randomized trials and eight non-randomized prospective trials, were included. A meta-analysis of all studies demonstrated an odds ratio (OR) of 0.66 (95% CI [0.56, 0.79], p < 0.00001) favoring IONM compared to the visual identification of the RLN in limiting permanent RLN injuries. A meta-analysis of studies employing contemporaneous controls and routine postoperative laryngoscopy to diagnose RLN injuries (considered to be the most reliable design) demonstrated an OR of 0.69 (95% CI [0.56, 0.84], p = 0.0003), favoring IONM. Strong consideration should be given to employing IONM when performing thyroid and parathyroid surgery.

Subjective Voice Outcomes in Surgeon Versus Technician-Monitored Recurrent Laryngeal Nerves in Thyroidectomy

OBJECTIVES

To compare subjective voice outcomes and postoperative laryngoscopic examination findings of patients with subjective voice complaints between surgeon-monitored and certified technician-monitored thyroidectomies.

METHODS

Patients who underwent hemithyroidectomy, total thyroidectomy, and completion thyroidectomy using a nerve monitoring system between November 2015 and June 2018 were included in the study. Retrospective chart review was carried out to assess how often patients reported voice changes and to record postoperative flexible laryngoscopic findings of patients when that examination was performed. Data were analyzed using the χ2 test to identify significant differences in outcomes for the 2 groups.

RESULTS

A total of 293 procedures was performed among 3 surgeons. Surgeons monitored the nerves in 147 cases and a certified technician monitored the nerves in 146 cases. Subjective voice changes were identified in 11 (7.48%) cases in the surgeon-monitored group and in 20 (13.70%) cases in the technician-monitored group (P = .084). Among the patients who expressed subjective voice changes, 7 patients were identified with vocal cord hypomobility or immobility in the surgeon-monitored group and 13 patients had an abnormal examination in the technician-monitored group (P = .234).

CONCLUSIONS

Subjective voice changes or proven vocal cord mobility problems were not different between surgeon-monitored patients and technician-monitored patients in thyroidectomies.

Sialendoscopy for treatment of major salivary glands diseases: a comprehensive analysis of published systematic reviews and meta-analyses

OBJECTIVES

Sialendoscopy is a minimally invasive procedure used to diagnose and treat obstructive salivary gland diseases. Previous studies in the topic have shown mixed results. The present study aimed to evaluate the efficacy and safety of sialendoscopy through previous systematic reviews for different outcomes of several diseases. We also aimed to assess studies' methodological quality and heterogeneity.

METHODS

We conducted a comprehensive systematic literature search of Pubmed, Embase, Lilacs and Cochrane Library. We included systematic reviews and meta-analyses that used sialendoscopy to treat both lithiasic and alithiasic salivary glands diseases. Data extraction included studies' characteristics and results. We assessed studies' methodological quality using the AMSTAR-2 (A MeaSurement Tool to Assess systematic Reviews 2) tool.

RESULTS

13 studies were included in the review, being 9 in adult populations and 4 in pediatric populations. Sialendoscopy proved to be effective at the treatment of different lithiasic and other obstructive diseases, but with important heterogeneity. The technique was also considered highly safe in most studies. However, studies had a critically low quality of evidence.

CONCLUSIONS

Most studies demonstrated high efficacy and safety of sialendoscopy, but with critically low quality of evidence. We still lack randomized studies in this field, and future systematic reviews on the topic should follow current guidelines to improve conduction and reporting.

Visualization of the recurrent laryngeal nerve alone versus intraoperative nerve monitoring in primary thyroidectomy: a framework approach to a missing typology

INTRODUCTION

Surgical studies evaluating a device or technology in comparison to an established surgical technique should accurately report all the important components of the surgical technique in order to reduce the risk of intervention bias. In the debate of visualization of the recurrent laryngeal nerve alone (VONA) versus intraoperative nerve monitoring (IONM) during thyroidectomy, surgical technique plays a key role in both strategies. Our aim was to investigate whether the surgical technique was considered as a risk of intervention bias by relevant meta-analyses and reviews and if steps of surgical intervention were described in their included studies.

METHODS

We searched PUBMED, CENTRAL-Cochrane library, PROSPERO and GOOGLE for reviews and meta-analyses focusing on the comparison of IONM to VONA in primary open thyroidectomy. Τhen, primary studies were extracted from their reference lists. We developed a typology for surgical technique applied in primary studies and a framework approach for the evaluation of this typology by the meta-analyses and reviews.

RESULTS

Twelve meta-analyses, one review (388,252 nerves at risk), and 84 primary studies (128,720 patients) were included. Five meta-analyses considered the absence of typology regarding the surgical technique as a source of intervention bias; 48 primary studies (57.14%) provided information about at least one item of the typology components and only 1 for all of them.

DISCUSSION

Surgical technique of thyroidectomy in terms of a typology is underreported in studies and undervalued by meta-analyses comparing VONA to IONM. This missing typology should be reconsidered in the comparative evaluation of these two strategies.

AMSTAR 2 appraisal of systematic reviews and meta-analyses in the field of heart failure from high-impact journals

BACKGROUND

The Measurement Tool to Assess systematic Reviews (AMSTAR) 2 is a critical appraisal tool for systematic reviews (SRs) and meta-analyses (MAs) of interventions. We aimed to perform the first AMSTAR 2-based quality assessment of heart failure-related studies.

METHODS

Eleven high-impact journals were searched from 2009 to 2019. The included studies were assessed on the basis of 16 domains. Seven domains were deemed critical for high-quality studies. On the basis of the performance in these 16 domains with different weights, overall ratings were generated, and the quality was determined to be "high," "moderate," "low," or "critically low."

RESULTS

Eighty-one heart failure-related SRs with MAs were included. Overall, 79 studies were of "critically low quality" and two were of "low quality." These findings were attributed to insufficiency in the following critical domains: a priori protocols (compliance rate, 5%), complete list of exclusions with justification (5%), risk of bias assessment (69%), meta-analysis methodology (78%), and investigation of publication bias (60%).

CONCLUSIONS

The low ratings for these potential high-quality heart failure-related SRs and MAs challenge the discrimination capacity of AMSTAR 2. In addition to identifying certain areas of insufficiency, these findings indicate the need to justify or modify AMSTAR 2's rating rules.

Anatomical and functional identification of the external branch of the superior laryngeal nerve: classification based on morphology and electrophysiological monitoring

BACKGROUND

Motor function of the external branch of superior laryngeal nerve (EBSLN) is vital for voice quality. We studied the rate of EBSLN identification and integrity in the era of intraoperative neuromonitoring (IONM).

METHODS

Anatomic and functional identification of 515 EBSLNs-at-risk was performed under the guidance of IONM that motor integrity was electrophysiologically checked. The functional integrity was assessed with crico-thyroid muscle (CTM) twitches and/or recordable waveform amplitude. We tried to establish the systematic classification of EBSLN identification and integrity.

RESULTS

Visual, electrophysiological and total identification rates were 64.3%, 31.6% and 95.9%, respectively. We could identify 4.1% of EBSLNs neither anatomically nor electrophysiologically. We recorded CTM twitches alone or both CTM twitches and wave amplitude in 203(39.4%) and 291(56.5%) branches respectively. Identification features of EBSLNs were systematically classified under three main types: Visualized-monitored (1), non-visualized-monitored (2), unidentified (3), and electrophysiological integrity of EBSLNs under two subtypes: CTM twitches alone (a) and CTM twitches and wave amplitude (b).

CONCLUSION

Dedicated thyroid surgeon could visually identify EBSLNs. IONM contribution significantly increases the identification rate. Systematic classification of identification and electrophysiological integrity of EBSLNs may increase comprehensive knowledge about its motor function that is crucial for complication-free thyroidectomy.

Improving Voice Outcomes after Thyroid Surgery and Ultrasound-Guided Ablation Procedures

The field of endocrine surgery has expanded from the traditional open neck approach to include remote access techniques as well as minimally invasive approaches for benign and malignant thyroid nodules. In experienced hands and with careful patient selection, each approach is considered safe, however complications can and do exist. Post-operative dysphonia can have serious consequences to the patient by affecting quality of life and ability to function at work and in daily life. Given the significance of post-procedural dysphonia, we review the surgical and non-surgical techniques for minimizing and treating recurrent laryngeal nerve injury that can be utilized with the traditional open neck approach, remote access thyroidectomy, or minimally invasive thermal ablation.

Effects of Intraoperative Neural Tunnel in Protecting Recurrent Laryngeal Nerve: Experiences in Open, Trans Breast, and Transoral Endoscopic Thyroidectomy

Background

Energy-based devices (EBDs) increase the risks of thermal nerve injuries. This study aimed to introduce a surgical strategy of intraoperative neural tunnel protecting (INTP) for evaluating the effect in reducing the incidence of recurrent laryngeal nerve (RLN) damage in open, trans breast, and transoral endoscopic thyroidectomy.

Methods

INTP strategy was introduced: a tunnel was established and protected by endoscopic gauze along the direction of the nerve. A total of 165, 94, and 200 patients with papillary thyroid carcinoma (PTC) were to use INTP in respectively open, trans breast, and transoral endoscopic thyroidectomy as the INTP group. Additionally, 150, 95, and 225 patients who received the same methods without INTP were enrolled in the control group. Ipsilateral thyroidectomy or total thyroidectomy, and central compartment dissection were performed on the enrolled patients.

Results

Clinicopathologic characteristics, surgical outcomes, and surgical complications were similar between the INTP group and the control group in open, trans breast, and transoral endoscopic thyroidectomy. The incidences of electromyography (EMG) changes in the INTP group were lower as compared to the control group in trans breast endoscopic thyroidectomy (p < 0.05). The incidence of postoperative hoarse in the INTP group was lower as compared to the control group in open and transoral endoscopic thyroidectomy (p < 0.05). Postoperative calcium levels (p < 0.01) were significantly higher, and the white blood cells (p < 0.05) and C-reactive protein levels (p < 0.01) were significantly decreased in the INTP group compared with the control group in transoral endoscopic thyroidectomy.

Conclusions

This was the first instance of the INTP strategy being introduced and was found to be an effective method for protecting the RLN in open, trans breast, and transoral endoscopic thyroidectomy. Additionally, INTP helped protect other important tissues such as the parathyroid glands in transoral endoscopic thyroidectomy as well as in reducing postoperative inflammatory responses.

A Surgeon-Centered Neuromuscular Block Protocol Improving Intraoperative Neuromonitoring Outcome of Thyroid Surgery

BACKGROUND

Neuromuscular blocking agents provide muscular relaxation for tracheal intubation and surgery. However, the degree of neuromuscular block may disturb neuromuscular transmission and lead to weak electromyography during intraoperative neuromonitoring. This study aimed to investigate a surgeon-friendly neuromuscular block degree titrated sugammadex protocol to maintain both intraoperative neuromonitoring quality and surgical relaxation during thyroid surgery.

METHODS

A total of 116 patients were enrolled into two groups and underwent elective thyroid surgery with intraoperative neuromonitoring. All patients followed a standardized intraoperative neuromonitoring protocol with continuous neuromuscular transmission monitoring and received 0.6 mg/kg rocuronium for tracheal intubation. Patients were allocated into two groups according to the degree of neuromuscular block when the anterior surface of the thyroid gland was exposed. The neuromuscular block degree was assessed by the train-of-four (TOF) count and ratio. Patients in group I received sugammadex 0.25 mg/kg for non-deep neuromuscular block degree (TOF count = 1~4). Patients in group II were administered sugammadex 0.5 mg/kg for deep neuromuscular block degree (TOF count = 0). The quality of the intraoperative neuromonitoring was measured using the V₁ electromyography (EMG) amplitude. An amplitude less than 500 μV and greater than 500 μV was defined as weak and satisfactory, respectively.

RESULTS

The quality of the intraoperative neuromonitoring was not different between groups I and II (satisfactory/weak: 75/1 vs. 38/2, P = 0.14). The quality of surgical relaxation was acceptable after sugammadex injection and showed no difference between groups [55/76 (72.3%) in group I vs. 33/40 (82.5%) in group II, P = 0.23].

CONCLUSIONS

This surgeon-centered sugammadex protocol guided by neuromuscular block degree (0.5 mg/kg for deep block and 0.25 mg/kg for others) showed comparably high intraoperative neuromonitoring quality and adequate surgical relaxation. The results expanded the practicality of sugammadex for precise neuromuscular block management during monitored thyroidectomy.

Prophylactic central neck dissection for well-differentiated thyroid carcinoma: results and methodological assessment of systematic reviews

OBJECTIVE

The aim was to assess the methodological quality of systematic reviews evaluating the effectivness of prophylactic central neck dissection plus thyroidectomy to decrease locoregional recurrence in patients with thyroid carcinoma.

INTRODUCTION

Many systematic reviews have been published concerning prophylactic central neck dissection in well-differentiated thyroid carcinoma, finding inconsistent results regarding the risk of locoregional recurrence. Because systematic reviews are considered the best source on which to base clinical decisions, the assessment of methodological quality is important.

INCLUSION CRITERIA

This paper included studies that mentioned that a systematic review was performed in adult patients with confirmed diagnosis of well-differentiated thyroid carcinoma without evidence of nodal metastatic disease who underwent total thyroidectomy. Reviews evaluated prophylactic central neck dissection compared with no neck diessection for decreasing locoregional recurrence.

METHODS

A systematic search was performed using MEDLINE, Embase, the Cochrane Database of Systematic Reviews, LILACS, Web of Science, CNKI, and Google Scholar. PROSPERO was searched for unpublished studies and gray literature. Data regarding the study characteristics, patient types, numbers of patients, and locoregional recurrence by group were extracted. Methodological characteristics, type of statistical analysis and summary estimator, heterogeneity, and publication bias were recorded. The methodological quality was measured using the AMSTAR 2 tool.

RESULTS

The search identified 12 systematic reviews. Only four systematic reviews reported adherence to methodological guidelines. The AMSTAR 2 critical criteria classified all the studies as critically low quality. The pooled risk difference for locoregional recurrence varied among studies from -5% to 0%. Most of the studies were published in high-impact journals.

CONCLUSIONS

The published systematic reviews that assessed prophylactic central neck dissection as an intervention to decrease the rate of locoregional recurrence have a critically low methodological quality. The results and recommendations based on these studies should be used with caution. The evaluation of methodological quality by peer reviewers must be improved.

Intraoperative nerve monitoring in thyroid surgery: analysis of United Kingdom registry of endocrine and thyroid surgery database

BACKGROUND

Intraoperative nerve monitoring (IONM) is used increasingly in thyroid surgery to prevent recurrent laryngeal nerve (RLN) injury, despite lack of definitive evidence. This study analysed the United Kingdom Registry of Endocrine and Thyroid Surgery (UKRETS) to investigate whether IONM reduced the incidence of RLN injury.

METHODS

UKRETS data were extracted on 28 July 2018. Factors related to risk of RLN palsy, such as age, sex, retrosternal goitre, reoperation, use of energy devices, extent of surgery, nodal dissection and IONM, were analysed. Data with missing entries for these risk factors were excluded. Outcomes of patients who had preoperative and postoperative laryngoscopy were analysed.

RESULTS

RLN palsy occurred in 4.9 per cent of thyroidectomies. The palsy was temporary in 64.6 per cent and persistent in 35.4 per cent of patients. In multivariable analysis, IONM reduced the risk of RLN palsy (odds ratio (OR) 0.63, 95 per cent confidence interval (CI) 0.54 to 0.74, P < 0.001) and persistent nerve palsy (OR 0.47, 0.37 to 0.61, P < 0.001). Outpatient laryngoscopy was also associated with a reduced incidence of RLN palsy (OR 0.50, 0.37 to 0.67, P < 0.001). Bilateral RLN palsy occurred in 0.3 per cent. Reoperation (OR 12.30, 2.90 to 52.10, P = 0.001) and total thyroidectomy (OR 6.52, 1.50 to 27.80; P = 0.010) were significantly associated with bilateral RLN palsy.

CONCLUSION

The use of IONM is associated with a decreased risk of RLN injury in thyroidectomy. These results based on analysis of UKRETS data support the routine use of RLN monitoring in thyroid surgery.

Scoping review of COVID-19-related systematic reviews and meta-analyses: can we really have confidence in their results?

Aim

The aim of this study was to systematically appraise the quality of a sample of COVID-19-related systematic reviews (SRs) and discuss internal validity threats affecting the COVID-19 body of evidence.

Design

We conducted a scoping review of the literature. SRs with or without meta-analysis (MA) that evaluated clinical data, outcomes or treatments for patients with COVID-19 were included.

Main outcome measures

We extracted quality characteristics guided by A Measurement Tool to Assess Systematic Reviews-2 to calculate a qualitative score. Complementary evaluation of the most prominent published limitations affecting the COVID-19 body of evidence was performed.

Results

A total of 63 SRs were included. The majority were judged as a critically low methodological quality. Most of the studies were not guided by a pre-established protocol (39, 62%). More than half (39, 62%) failed to address risk of bias when interpreting their results. A comprehensive literature search strategy was reported in most SRs (54, 86%). Appropriate use of statistical methods was evident in nearly all SRs with MAs (39, 95%). Only 16 (33%) studies recognised heterogeneity in the definition of severe COVID-19 as a limitation of the study, and 15 (24%) recognised repeated patient populations as a limitation.

Conclusion

The methodological and reporting quality of current COVID-19 SR is far from optimal. In addition, most of the current SRs fail to address relevant threats to their internal validity, including repeated patients and heterogeneity in the definition of severe COVID-19. Adherence to proper study design and peer-review practices must remain to mitigate current limitations.

Associations between gastro-oesophageal reflux disease and a range of diseases: an umbrella review of systematic reviews and meta-analyses

OBJECTIVE

Numerous meta-analyses have revealed the association between gastro-oesophageal reflux disease (GORD) and a range of diseases; however, the certainty of the evidence remains unclear. This study aimed to summarise and assess the certainty of evidence derived from meta-analyses.

METHODS

Embase, PubMed, Web of Science, Cochrane Databases of Systematic Reviews, CNKI and Wangfang databases from their inception to 22 February 2020 were queried for systematic reviews and meta-analyses on the association between GORD and various diseases. The methodological quality of the included studies was assessed using A Measurement Tool to Assess Systematic Reviews 2 (AMSTAR 2), and evidence certainty was evaluated using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) system. Statistical analysis was conducted using Stata V.15.

RESULTS

Ten publications with associations between GORD and different types of diseases were included. There was high heterogeneity (I² >75%) among seven independent meta-analyses. Evidence for publication bias in two independent meta-analyses was also observed. According to the AMSTAR 2 approach, the methodological quality was high for 20% of meta-analyses, moderate for 10%, low for 40% and critically low for 30%. Based on GRADE approach, the certainty of evidence was high for the association between GORD and higher risk of chronic obstructive pulmonary disease (COPD) exacerbation (OR 5.37; 95% CI 2.71 to 10.64) and higher prevalence of oesophageal adenocarcinoma (OR 4.57; 95% CI 3.89 to 5.36), and it was moderate for the association between GORD and higher chronic rhinosinusitis prevalence (OR 2.16; 95% CI 1.37 to 3.48).

CONCLUSION

The association between GORD and a range of diseases was extensively studied, and our findings revealed a high certainty of evidence of the association between GORD and an increased risk of COPD exacerbation as well as increased prevalence of oesophageal adenocarcinoma. Further investigations using systematic reviews and meta-analyses of high methodological quality that include prospective large cohort studies and adjusted confounders are warranted.

PROSPERO REGISTRATION NUMBER

CRD42019122264.

Continuous Laryngeal Adductor Reflex Versus Intermittent Nerve Monitoring in Neck Endocrine Surgery

OBJECTIVE

Intraoperative neuromonitoring (IONM) techniques aim to identify and potentially prevent nerve injury during surgeries. Prior studies into the efficacy of recurrent laryngeal nerve (RLN) IONM convey mixed results, with some claiming equivalence between IONM and no monitoring at all. The goal of the current study was to compare continuous RLN monitoring using the laryngeal adductor reflex (LAR) to intermittent RLN monitoring (intermittent IONM) to determine whether continuous monitoring reduces the incidence of intraoperative RLN injury during neck endocrine surgeries.

METHODS

In this observational, historical case-control study, a historical cohort of patients monitored with intermittent-IONM (group 1, n = 130) were compared to prospectively collected data from consecutive nerves-at-risk monitored continuously with the LAR (LAR-CIONM, group 2, n = 205), at a single center by a single surgeon. The test benefit ratio and relative risk reduction (RRR) for LAR-CIONM over intermittent IONM were calculated.

RESULTS

For group 1, nine nerves at risk exhibited intraoperative LOS with transient postoperative vocal fold (VF) hypomobility (n = 2) or immobility (VFI, n = 7). For group 2, two nerves at risk (0.98%) had sudden intraoperative LAR LOS following bipolar cautery, resulting in postoperative transient VFI (P = .004). In each group, there was one case of permanent postoperative VFI. The test benefit rate ratio for LAR-CIONM demonstrated a dramatic effect at 5.23, with an RRR of 81.0%.

CONCLUSION

LAR-CIONM significantly decreased rates of postoperative transient VF paralysis and paresis over intermittent IONM alone (P = .004). Surgeons should be aware of the benefits and limitations of intermittent IONM versus CIONM. Intermittent IONM, although useful in nerve mapping and intraoperative decision making, has minimal benefit for the prevention of nerve injury, whereas CIONM can potentially reduce nerve injury rates and improve patient outcomes.

LEVEL OF EVIDENCE

3 Laryngoscope, 131:230-236, 2021.

Association between H. pylori infection and health Outcomes: an umbrella review of systematic reviews and meta-analyses

OBJECTIVE

Systematic reviews and meta-analyses have revealed the associations between H. pylori infection and various health outcomes. We aimed to evaluate the strength and breadth of evidence on the associations.

DESIGN

Umbrella review of systematic reviews and meta-analyses.

SETTING

No settings.

PARTICIPANTS

No patients involved.

DATA SOURCES

Embase, PubMed, Web of Science, Cochrane Library Databases, CNKI, VIP database and Wangfang database from inception to February 1, 2019.

OUTCOMES MEASURES

Diverse diseases (such as cancer and ischaemic heart disease).

RESULTS

Sixty articles reporting 88 unique outcomes met the eligible criteria. 74 unique outcomes had nominal significance (p<0.05). Of the outcomes with significance, 61 had harmful associations and 13 had beneficial associations. Furthermore, 73% (64) of the outcomes exhibited significant heterogeneity . Of the these meta-analyses, 32 had moderate to high heterogeneity (I²=50%-75%) and 24 had high heterogeneity (I²>75%). Moreover, 20% exhibited publication bias (p<0.1). In addition, 97% of the methodological qualities were rated 'critically low'. 36% of the evidence qualities of outcomes were rated 'low', 56% of the evidence qualities were rated 'very low' and 8% of the evidence qualities were rated 'moderate'. H. pylori infection may be associated with an increased risk of five diseases and a decreased risk of irritable bowel syndrome.

CONCLUSION

Although 60 meta-analyses explored 88 unique outcomes, moderate quality evidence only existed for six outcomes with statistical significance. H. pylori infection may be associated with a decreased risk of irritable bowel syndrome and an increased risk of hypertriglyceridemia, chronic cholecystitis and cholelithiasis, gestational diabetes mellitus, gastric cancer and systemic sclerosis.

TRIAL REGISTRATION

CRD42019124680.