Randomized controlled trials comparing surgery to non-operative management in neurosurgery: a systematic review

Addressing the role of surgery in brain tumour trials: A report from the neurosurgery committee of the EORTC brain tumour group

The Brain Tumor Group (BTG) of the European Organization for Research and Treatment of Cancer (EORTC) conducts academic clinical trials and translational research to improve clinical management of patients with primary and secondary brain tumors. The EORTC BTG has traditionally played an important role in providing evidence and thus advancing the field, albeit with a main focus on radiotherapy and pharmacotherapy in gliomas. Although examples of well-designed neuro-oncological surgical trials can be found, evidence in surgical neuro-oncology predominantly includes data from uncontrolled prospective series or retrospective cohorts. By means of a thorough literature and EORTC database review, we demonstrate, firstly, that while the pathway of the neuro-oncology patient most often starts with neurosurgery, its several aspects have traditionally been poorly acknowledged in clinical trials in neuro-oncology. We also show that the definitions and methods of assessment vary greatly between studies, limiting generalizability. The newly established Neurosurgery Committee of the EORTC BTG aims to address this gap by increasing the number of prospective surgical trials, but also the involvement of neurosurgeons in clinical trial design, promoting standardized terminology for description of the surgical aspects, including extent of resection. We will also explore alternative trial designs when randomization is deemed difficult, as well as focus on defining surgical quality indicators that influence outcome. By addressing these challenges, the committee aims to enhance the quality of neurosurgical evidence in neuro-oncology and define optimal surgical methods and standards of care. This should ultimately improve outcomes and quality of life for patients with brain tumors through evidence-based surgical interventions.

The death of a neurotrauma trial lessons learned from the prematurely halted randomized evaluation of surgery in elderly with traumatic acute subdural hematoma (RESET-ASDH) trial

Introduction

Acute subdural hematoma (ASDH) due to traumatic brain injury (TBI) constitutes an increasing global health problem, especially in the elderly population. Treatment decisions on surgical versus conservative management pose a neurosurgical dilemma. Large practice variation exists between countries, hospitals, and individual neurosurgeons, illustrating the presence of 'clinical equipoise'. The RESET-ASDH trial aimed to address this dilemma but was terminated prematurely due to insufficient patient recruitment.

Research question

What factors may have contributed to the premature discontinuation of the RESET-ASDH trial?

Materials and methods

The RESET-ASDH was a multicenter randomized controlled trial (RCT) comparing functional outcome at 1 year after early surgery or an initial conservative treatment in elderly patients (≥65 years) with a traumatic ASDH. Logs of registry data, medical-ethical approval timelines and COVID-19 related research documents were analyzed. Furthermore, non-structured interviews with involved clinical research personnel were conducted.

Results

The concept of clinical equipoise was broadly misinterpreted by neurosurgeons as individual uncertainty, hampering patient recruitment. Also, the elderly target population complicated the inclusion process as elderly and their informal caregivers were hesitant to participate in our acute surgical trial. Moreover, the COVID-19 pandemic added additional hurdles like delayed medical-ethical approval, a decline in eligible patients and repeated trial halts during the peaks of the pandemic.

Discussion and conclusion

The premature termination of the RESET-ASDH study may have been related to the trial's methodology and target population with an additional impact of COVID-19. Future acute neurosurgical trials in elderly may consider these challenges to prevent premature trial termination.

Robustness of Randomized Control Trials Supporting Current Neurosurgery Guidelines

BACKGROUND

Treatment guidelines in neurosurgery are often based on evidence obtained from randomized controlled trials (RCTs).

OBJECTIVE

To evaluate the robustness of RCTs supporting current central nervous tumor and cerebrovascular disease guidelines by calculating their fragility index (FI)-the minimum number of patients needed to switch from an event to nonevent outcome to change significant trial primary outcome.

METHODS

We analyzed RCTs referenced in the Congress of Neurological Surgeons and American Association of Neurological Surgeons guidelines on central nervous tumor and cerebrovascular disease management. Trial characteristics, finding of a statistically significant difference in the primary endpoint favoring the experimental intervention, the FI, and FI minus number lost to follow-up were assessed.

RESULTS

Of 312 RCTs identified, 158 (50.6%) were published from 2000 to 2010 and 106 (34%) after 2010. Sixty-three trials (19.2%) were categorized as surgical trials, and the rest studied medical treatment (82.0%) or percutaneous intervention (8.33%). The trials had a median power of 80.0% (IQR 80.0-90.0). Of these, 120 trials were eligible for FI calculation. The median FI was 7.0 (IQR 2.0-16.25). Forty-four (36.6%) trials had FI ≤ 3 indicating very low robustness. After adjusting for covariates, recently published trials and trials studying percutaneous interventions were associated with significantly higher FI compared with older trials and trials comparing surgical approaches, respectively. Trials limited to single centers were associated with significantly lower FI.

CONCLUSION

Trials supporting current guidelines on neuro-oncological and neurovascular surgical interventions have low robustness. While the robustness of trials has improved over time, future guidelines must take into consideration this metric in their recommendations.

Is it feasible and ethical to randomize patients between surgery and non-surgical treatments for gastrointestinal cancers?

Background

In several settings in the treatment of gastrointestinal cancers, it is unclear if the addition of surgery to a multimodal treatment strategy, or in some circumstances its omission, lead to a better outcome for patients. In such situations of clinical equipoise, high-quality evidence from randomised-controlled trials is needed to decide which treatment approach is preferable.

Objective

In this article, we outline the importance of randomised trials comparing surgery with non-surgical therapies for specific scenarios in the treatment of gastrointestinal cancers. We explain the difficulties and solutions of designing these trials and recruiting patients in this context.

Methods

We performed a selective review based on a not systematic literature search in core databases, supplemented by browsing health information journals and citation searching. Only articles in English were selected. Based on this search, we discuss the results and methodological characteristics of several trials which randomised patients with gastrointestinal cancers between surgery and non-surgical treatments, highlighting their differences, advantages, and limitations.

Results and conclusions

Innovative and effective cancer treatment requires randomised trials, also comparing surgery and non-surgical treatments for defined scenarios in the treatment of gastrointestinal malignancies. Nevertheless, potential obstacles to designing and carrying out these trials must be recognised ahead of time to avoid problems before or during the trial.

Assessing the Success and Sustainability of Global Neurosurgery Collaborations: Systematic Review and Adaptation of the Framework for Assessment of InteRNational Surgical Success Criteria

BACKGROUND

The high unmet neurosurgical burden in low- and middle-income countries has necessitated multiple global neurosurgical collaborations. We identified these collaborations and their peer-reviewed journal publications and evaluated them using a modified version of the Framework for Assessment of InteRNational Surgical Success (FAIRNeSS).

METHODS

A systematic literature review yielded 265 articles describing neurosurgery-focused collaborations. A subset of 101 papers from 17 collaborations were evaluated with the modified FAIRNeSS criteria. Analysis of trends was performed for both individual articles and collaborations.

RESULTS

Most of the articles were general reviews (64), and most focused on clinical research (115). The leading collaboration focus was workforce and infrastructure development (45%). Composite FAIRNeSS scores ranged from 7/34 to 30/34. Average FAIRNeSS scores for individual articles ranged from 0.25 to 26.75, while collaboration-wide FAIRNeSS score averages ranged from 5.25 to 20.04. There was significant variability within each subset of FAIRNeSS indicators (P value <0.001). Short-term goals had higher scores than medium- and long-term goals (P value <0.001). Collaboration composite scores correlated with the number of papers published (R2 = 0.400, P = 0.007) but not with the number of years active (R2 = 0.072, P = 0.3). Finally, the overall agreement between reviewers was 53.5%, and the overall correlation was 38.5%.

CONCLUSIONS

Global neurosurgery has no established metrics for evaluating collaborations; therefore, we adapted the FAIRNeSS criteria to do so. The criteria may not be well suited for measuring the success and sustainability of global neurosurgery collaborations, creating a need to develop a more applicable alternate set of metrics.

Randomized controlled trials in neurosurgery

Randomized controlled trials (RCTs) have become the standard method of evaluating new interventions (whether medical or surgical), and the best evidence used to inform the development of new practice guidelines. When we review the history of medical versus surgical trials, surgical RCTs usually face more challenges and difficulties when conducted. These challenges can be in blinding, recruiting, funding, and even in certain ethical issues. Moreover, to add to the complexity, the field of neurosurgery has its own unique challenges when it comes to conducting an RCT. This paper aims to provide a comprehensive review of the history of neurosurgical RCTs, focusing on some of the most critical challenges and obstacles that face investigators. The main domains this review will address are: (1) Trial design: equipoise, blinding, sham surgery, expertise-based trials, reporting of outcomes, and pilot trials, (2) trial implementation: funding, recruitment, and retention, and (3) trial analysis: intention-to-treat versus as-treated and learning curve effect.

Is there resource wastage in the research for spinal diseases? An observational analysis of discontinuation and non-publication in randomised controlled trials

Introduction

The scale of waste in research funding systems is large and detrimental to research capacity. Both incompleteness and non-publication of Randomised Controlled Trials (RCTs) have been increasingly reported in the literature. This is a serious consequence as RCTs demand monumental amounts of healthcare resources leading to wastage. Most importantly, both under-reporting and non-publication can distort the evidence landscape and obscure rationale behind clinical decisions.

Research question

We, therefore, aimed at conducting the first systematic assessment of registered trial discontinuation and non-publication in the field of spinal disorders.

Material and methods

A list of RCTs was obtained from the U.S National Library of Medicine ClinicalTrials.gov database from January 1st, 2013, to December 31st, 2020. Two independent authors excluded all non-RCTs, trials unrelated to spinal diseases, and trials that are in or before the recruitment phase. We extracted the progress status, sources of funding, the number of centres, type of intervention, principal investigator's department affiliation, publication status, location, the reason for discontinuation, publication date, and subtopics.

Results

112 trials were included in the study. 25 (22%) trials were discontinued early, with slow recruitment being the major reason (38%). Only 56 (50%) of the trials were published in peer-reviewed journals. The publication rate amongst discontinued trials was significantly lower compared to completed trials (P ​< ​0·001). The trial discontinuation rate was much higher in trials registered in the United States (US) compared to other countries (P ​= ​0·009). Industry-sponsored studies had 11 trials (23·4%) that were discontinued whilst there was 20% of non-industry-sponsored studies that were unfinished. Only 20% of the trials were compliant with the FDA reporting requirements over the study period.

Discussion and conclusion

Nearly a quarter of all trials in spinal disorders were discontinued. Half of the trials were unpublished. There was over a third of trials that were completed but not published. These rates remain worrisome from an ethical and financial perspective. Both under-reporting and non-publication adversely affect efforts in evidence synthesis and can compromise clinical guideline development.

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Nearly a quarter of all trials in spinal disorders were discontinued early.

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Only half of the trials were published in peer-reviewed journals.

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Over a third of the trials were completed but not published.

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The rates of trial discontinuation and non-publication are worrisome from an ethical and financial perspective.

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Both under-reporting and non-publication adversely affect efforts in evidence synthesis and can compromise clinical guideline development.

Comparative Effectiveness of Stereotactic Electroencephalography Versus Subdural Grids in Epilepsy Surgery

OBJECTIVE

The aim was to compare the outcomes of subdural electrode (SDE) implantations versus stereotactic electroencephalography (SEEG), the 2 predominant methods of intracranial electroencephalography (iEEG) performed in difficult-to-localize drug-resistant focal epilepsy.

METHODS

The Surgical Therapies Commission of the International League Against Epilepsy created an international registry of iEEG patients implanted between 2005 and 2019 with ≥1 year of follow-up. We used propensity score matching to control exposure selection bias and generate comparable cohorts. Study endpoints were: (1) likelihood of resection after iEEG; (2) seizure freedom at last follow-up; and (3) complications (composite of postoperative infection, symptomatic intracranial hemorrhage, or permanent neurological deficit).

RESULTS

Ten study sites from 7 countries and 3 continents contributed 2,012 patients, including 1,468 (73%) eligible for analysis (526 SDE and 942 SEEG), of whom 988 (67%) underwent subsequent resection. Propensity score matching improved covariate balance between exposure groups for all analyses. Propensity-matched patients who underwent SDE had higher odds of subsequent resective surgery (odds ratio [OR] = 1.4, 95% confidence interval [CI] 1.05, 1.84) and higher odds of complications (OR = 2.24, 95% CI 1.34, 3.74; unadjusted: 9.6% after SDE vs 3.3% after SEEG). Odds of seizure freedom in propensity-matched resected patients were 1.66 times higher (95% CI 1.21, 2.26) for SEEG compared with SDE (unadjusted: 55% seizure free after SEEG-guided resections vs 41% after SDE).

INTERPRETATION

In comparison to SEEG, SDE evaluations are more likely to lead to brain surgery in patients with drug-resistant epilepsy but have more surgical complications and lower probability of seizure freedom. This comparative-effectiveness study provides the highest feasible evidence level to guide decisions on iEEG. ANN NEUROL 2021;90:927-939.

Absence of small study effects in neurosurgical meta-analyses: A meta-epidemiological study

BACKGROUND

Small studies are prone to lower methodological quality and publication bias, and are more likely to report greater beneficial effects. A meta-epidemiological study was undertaken to investigate and quantify the impact of small study effects on meta-analyses in the neurosurgical literature.

METHODS

A PubMed search was used to procure meta-analyses from Journal of Neurosurgery, Neurosurgery, Spine, Acta Neurochirurgica and Journal of Neurotrauma. Outcome data were extracted from meta-analyses the effect of study size was estimated by calculating the ratio of odds ratios (RORs) between small and large studies.

RESULTS

16 meta-analyses of 229 primary studies and 90,629 patients were included. All but two included pooled outcomes were significantly different from 1. On average small studies did not demonstrate greater beneficial effects, with an estimated pooled ROR of 1.32 (95% CI, 0.89 to 1.75). Stratification by meta-analysis effect size and heterogeneity yielded similar findings.

CONCLUSIONS

The absence of small study effects in meta-analyses of neurosurgical studies may reflect widespread poor quality of the neurosurgical literature affecting both large and small studies, rather than an absence of publication bias.

Treatment of ruptured aneurysms of the choroidal collateral system in moyamoya disease: a systematic review and data analysis

OBJECTIVE

Moyamoya disease (MMD) is a chronic, progressive steno-occlusive condition of the distal internal carotid arteries of unknown etiology. Collateral arterial networks typically develop in MMD, bypassing the steno-occlusion. Aneurysms arising on the collateral networks are a known source of hemorrhage. The choroidal collateral system is the most common location for collateral pathway aneurysms in MMD and associated hemorrhage. The authors performed data collection and analysis to further elucidate the best treatment approaches for ruptured aneurysms of the choroidal collateral system in MMD, which as yet remain unclear.

METHODS

A comprehensive data collection and analysis of case reports and case series with ruptured choroidal collateral artery aneurysms (CCAAs) was performed. PRISMA guidelines for systematic reviews were followed and the Medline, Embase, and Scopus databases were searched for relevant studies. A database was created including patients with ruptured CCAA in MMD. Original data from case series were included whenever possible. A previously unreported case of a ruptured choroidal artery aneurysm in MMD treated by the authors was also included.

RESULTS

The database comprised 72 patients with ruptured CCAA in MMD. The most common clinical symptoms were headache, nausea, and vomiting (39%). Initially, a conservative treatment approach was chosen in 29% of cases but led to rehemorrhage in 40% of cases; 63% of these rehemorrhages occurred during the first 35 days. Endovascular treatment seemed a safe option for aneurysm exclusion, mainly through parent vessel sacrifice, but had a treatment failure rate of 21%, due to inadequate access. Aneurysm treatment with revascularization as the initial treatment strategy led to aneurysm regression in 82% with no reported rehemorrhage. Aneurysm exclusion through open surgery was effective but was associated with a relatively high complication rate (25%). Outcome after rupture of CCAA was poor, with 41% of patients deceased or permanently disabled. Overall, patient outcomes were better in the endovascular and revascularization treatment group than in the conservative treatment group.

CONCLUSIONS

Rupture of CCAA in MMD is associated with high morbidity and rerupture rate requiring urgent treatment.

More robust estimation of average treatment effects using kernel optimal matching in an observational study of spine surgical interventions

Inverse probability of treatment weighting (IPTW), which has been used to estimate average treatment effects (ATE) using observational data, tenuously relies on the positivity assumption and the correct specification of the treatment assignment model, both of which are problematic assumptions in many observational studies. Various methods have been proposed to overcome these challenges, including truncation, covariate-balancing propensity scores, and stable balancing weights. Motivated by an observational study in spine surgery, in which positivity is violated and the true treatment assignment model is unknown, we present the use of optimal balancing by kernel optimal matching (KOM) to estimate ATE. By uniformly controlling the conditional mean squared error of a weighted estimator over a class of models, KOM simultaneously mitigates issues of possible misspecification of the treatment assignment model and is able to handle practical violations of the positivity assumption, as shown in our simulation study. Using data from a clinical registry, we apply KOM to compare two spine surgical interventions and demonstrate how the result matches the conclusions of clinical trials that IPTW estimates spuriously refute.

The IDEAL framework in neurosurgery: a bibliometric analysis

BACKGROUND

The Idea, Development, Exploration, Assessment and Long-term study (IDEAL) framework was created to provide a structured way for assessing and evaluating novel surgical techniques and devices.

OBJECTIVES

The aim of this paper was to investigate the utilization of the IDEAL framework within neurosurgery, and to identify factors influencing implementation.

METHODS

A bibliometric analysis of the 7 key IDEAL papers on Scopus, PubMed, Embase, Web of Science, and Google Scholar databases (2009-2019) was performed. A second journal-specific search then identified additional papers citing the IDEAL framework. Publications identified were screened by two independent reviewers to select neurosurgery-specific articles.

RESULTS

The citation search identified 1336 articles. The journal search identified another 16 articles. Following deduplication and review, 51 relevant articles remained; 14 primary papers (27%) and 37 secondary papers (73%). Of the primary papers, 5 (36%) papers applied the IDEAL framework to their research correctly; two were aligned to the pre-IDEAL stage, one to the Idea and Development stages, and two to the Exploration stage. Of the secondary papers, 21 (57%) explicitly discussed the IDEAL framework. Eighteen (86%) of these were supportive of implementing the framework, while one was not, and two were neutral.

CONCLUSION

The adoption of the IDEAL framework in neurosurgery has been slow, particularly for early-stage neurosurgical techniques and inventions. However, the largely positive reviews in secondary literature suggest potential for increased use that may be achieved with education and publicity.

Randomized Controlled Trials in Functional Neurosurgery-Association of Device Approval Status and Trial Quality

INTRODUCTION

Randomized controlled trials (RCTs) have been critical in evaluating the safety and efficacy of functional neurosurgery interventions. Given this, we sought to systematically assess the quality of functional neurosurgery RCTs.

METHODS

We used a database of neurosurgical RCTs (trials published from 1961 to 2016) to identify studies of functional neurosurgical procedures (N = 48). We extracted data on the design and quality of these RCTs and quantified the quality of trials using Jadad scores. We categorized RCTs based on the device approval status at the time of the trial and tested the association of device approval status with trial design and quality parameters.

RESULTS

Of the 48 analyzed functional neurosurgery RCTs, the median trial size was 34.5 patients with a median age of 51. The most common indications were Parkinson's disease (N = 20), epilepsy (N = 10), obsessive-compulsive disorder (N = 4), and pain (N = 4). Most trials reported inclusion and exclusion criteria (95.8%), sample size per arm (97.9%), and baseline characteristics of the patients being studied (97.9%). However, reporting of allocation concealment (29.2%), randomization mode (66.7%), and power calculations (54.2%) were markedly less common. We observed that trial quality has improved over time (Spearman r, 0.49). We observed that trials studying devices with humanitarian device exemption (HDE) and experimental indications (EI) tended to be of higher quality than trials of FDA-approved devices (p = 0.011). A key distinguishing quality characteristic was the proportion of HDE and EI trials that were double-blinded, compared to trials of FDA-approved devices (HDE, 83.3%; EI, 69.2%; FDA-approved, 35.3%). Although more than one-third of functional neurosurgery RCTs reported funding from industry, no significant association was identified between funding source and trial quality or outcome.

CONCLUSION

The quality of RCTs in functional neurosurgery has improved over time but reporting of specific metrics such as power calculations and allocation concealment requires further improvement. Device approval status but not funding source was associated with trial quality.

Trends in High-Impact Neurosurgical Randomized Controlled Trials Published in General Medical Journals: A Systematic Review

BACKGROUND

The neurosurgery literature lacks a comprehensive report of neurosurgical randomized controlled trials (RCTs) published in general medical journals. RCTs published in these journals have high visibility and impact on decision-making by general medical practitioners and health care policymakers.

METHODS

A systematic review of neurosurgical RCTs in the New England Journal of Medicine, The Lancet, Journal of the American Medical Association, The BMJ, and Annals of Internal Medicine was completed.

RESULTS

There were 78 neurosurgical RCTs published in the selected high-impact journals from 2000 to 2017. The most common study topics were neurovascular (n = 39, 50%) and spine (n = 24, 30.8%). Of these RCTs, 44 (56.4%) compared operative with nonoperative management. For studies published before 2017, the mean number of citations was 899. Approximately half of the studies showed superiority of operative management over nonoperative management in the intent to treat primary outcome of interest (n = 24, 54.5%). However, stratified by subsubspecialty, 7 (87.5%) of the functional RCTs, 9 (50%) of the neurovascular RCTs, 1 (50%) of the trauma RCTs, and 7 (43.8%) of the spinal RCTs demonstrated superiority of operative management over nonoperative management. Additionally, there were large subspecialty differences in study characteristics, such as rate of double blinding, proportion of patient enrollment from patients screened, and proportion of crossover from nonsurgical to surgical arm.

CONCLUSIONS

Neurosurgical RCTs in general medical journals have large subspecialty differences in characteristics such as crossovers from nonsurgical to surgical treatment arms and the proportion of studies demonstrating benefit of operative intervention over nonoperative management.