Launching Effectiveness Research to Guide Practice in Neurosurgery: A National Institute Neurological Disorders and Stroke Workshop Report

Ethical Problems of Observational Studies and Big Data Compared to Randomized Trials

The temptation to use prospective observational studies (POS) instead of conducting difficult trials (RCTs) has always existed, but with the advent of powerful computers and large databases, it can become almost irresistible. We examine the potential consequences, were this to occur, by comparing two hypothetical studies of a new treatment: one RCT, and one POS. The POS inevitably submits more patients to inferior research methodology. In RCTs, patients are clearly informed of the research context, and 1:1 randomized allocation between experimental and validated treatment balances risks for each patient. In POS, for each patient, the risks of receiving inferior treatment are impossible to estimate. The research context and the uncertainty are down-played, and patients and clinicians are at risk of becoming passive research subjects in studies performed from an outsider's view, which potentially has extraneous objectives, and is conducted without their explicit, autonomous, and voluntary involvement and consent.

Decision-making patterns among expert and novice orthodontists and oral maxillofacial surgeons in the management of adults with Class III malocclusions and moderate degree of skeletal discrepancies

OBJECTIVE

To explore the decision-making patterns among expert and novice orthodontists and oral maxillofacial surgeons in the management of adults with Class III malocclusions and moderate skeletal discrepancies.

DESIGN

Self-administered questionnaire survey.

SETTING

Faculty of Dentistry, National University of Singapore and the University Dental Cluster, National University Hospital, Singapore.

PARTICIPANTS

A total of 55 clinicians, comprising 13 expert orthodontists, 20 novice orthodontists, 10 expert oral maxillofacial surgeons and 12 novice oral maxillofacial surgeons.

METHODS

Clinicians assessed six adults with a Class III malocclusion and moderate skeletal discrepancy. They were asked to decide who could be managed exclusively by orthodontic camouflage, who would require combined orthodontic-orthognathic surgery as the only viable treatment, or who could be offered both treatment options.

RESULTS

The study found variable decision-making patterns among the clinicians in each case. Only 18.2%-40.0% of clinicians agreed that the cases selected were of moderate skeletal discrepancies and could be offered both treatment options whereas the rest were either more inclined to recommend orthodontic camouflage or orthognathic surgery. Intra-clinician agreement (n = 20) was only fair (Kappa value = 0.31). There was only slight inter-clinician agreement (n = 55) on their clinical decisions (Kappa value = 0.10). Clinical experience and dental specialty did not significantly influence clinicians' decisions. Oral and maxillofacial surgeons were 1.98 times more likely to indicate orthognathic surgery as the only viable treatment compared to the orthodontists (95% confidence interval = 1.15-3.42).

CONCLUSION

Variability in the patterns of decision-making for adults with a Class III malocclusion and moderate skeletal discrepancy was observed among the clinicians with low repeatability and agreement.

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.

Low grade gliomas guide-lines elaborated by the tumor section of Spanish Society of Neurosurgery

Adult low-grade gliomas (Low Grade Gliomas, LGG) are tumors that originate from the glial cells of the brain and whose management involves great controversy, starting from the diagnosis, to the treatment and subsequent follow-up. For this reason, the Tumor Group of the Spanish Society of Neurosurgery (GT-SENEC) has held a consensus meeting, in which the most relevant neurosurgical issues have been discussed, reaching recommendations based on the best scientific evidence. In order to obtain the maximum benefit from these treatments, an individualised assessment of each patient should be made by a multidisciplinary team. Experts in each LGG treatment field have briefly described it based in their experience and the reviewed of the literature. Each area has been summarized and focused on the best published evidence. LGG have been surrounded by treatment controversy, although during the last years more accurate data has been published in order to reach treatment consensus. Neurosurgeons must know treatment options, indications and risks to participate actively in the decision making and to offer the best surgical treatment in every case.

Patient Selection in a Pragmatic Study on the Management of Patients with Brain Arteriovenous Malformations

BACKGROUND

The Treatment of Brain Arteriovenous Malformations Study (TOBAS) is an all-inclusive pragmatic study comprising 2 randomized clinical trials (RCTs). Patients excluded from the RCTs are followed in parallel treatment and observation registries, allowing a comparison between RCT and registry patients.

METHODS

The first randomized clinical trial (RCT-1) offers 1:1 randomized allocation of intervention versus conservative management for patients with arteriovenous malformation (AVM). The second randomized clinical trial (RCT-2) allocates 1:1 pre-embolization or no pre-embolization to surgery or radiosurgery patients judged treatable with or without embolization. Characteristics of RCT patients are reported and compared to registry patients.

RESULTS

From June 2014 to May 2021, 1010 patients with AVM were recruited; 498 patients were observed and 373 were included in the treatment registries. Randomized allocation in RCT-1 was applied to 139 (26%) of the 512 patients (including 127 of 222 [57%] with unruptured AVMs) considered for curative treatment. RCT-1 AVM patients differed (in rupture status, Spetzler-Martin grade and baseline modified Rankin Score) from those in the observation or treatment registries (P < 0.001). Most patients had small (<3 cm; 71%) low-grade (Spetzler-Martin I-II; 64%) unruptured (91%) AVMs. The allocated management was conservative (n = 71) or curative (n = 68), using surgery (n = 39), embolization (n = 16), or stereotactic radiosurgery (n = 13). Pre-embolization was considered for 179/309 (58%) patients allocated/assigned to surgery or stereotactic radiosurgery; 87/179 (49%) were included in RCT-2. RCT-2 patient AVMs differed in size, eloquence and grade from patients of the pre-embolization registry (P < 0.01). Most had small (<3 cm in 82%) low-grade (83%) AVMs in non-eloquent brain (64%).

CONCLUSIONS

Patients included in the RCTs differ significantly from registry patients. Meaningful results can be obtained if multiple centers actively participate in the TOBAS RCTs.

Surgical treatment of brainstem cavernous malformations: an international Delphi consensus

OBJECTIVE

Indication for surgery in brainstem cavernous malformations (BSCMs) is based on many case series, few comparative studies, and no randomized controlled trials. The objective of this study was to seek consensus about surgical management aspects of BSCM.

METHODS

A total of 29 experts were invited to participate in a multistep Delphi consensus process on the surgical treatment of BSCM.

RESULTS

Twenty-two (76%) of 29 experts participated in the consensus. Qualitative analysis (content analysis) of an initial open-ended question survey resulted in 99 statements regarding surgical treatment of BSCM. By using a multistep survey with 100% participation in each round, consensus was reached on 52 (53%) of 99 statements. These were grouped into 4 categories: 1) definitions and reporting standards (7/14, 50%); 2) general and patient-related aspects (11/16, 69%); 3) anatomical-, timing of surgery-, and BSCM-related aspects (22/37, 59%); and 4) clinical situation-based decision-making (12/32, 38%). Among other things, a consensus was reached for surgical timing, handling of associated developmental venous anomalies, handling of postoperative BSCM remnants, assessment of specific anatomical BSCM localizations, and treatment decisions in typical clinical BSCM scenarios.

CONCLUSIONS

A summary of typical clinical scenarios and a catalog of various BSCM- and patient-related aspects that influence the surgical treatment decision have been defined, rated, and interpreted.

The Japan Neurosurgical Database: Statistics Update 2018 and 2019

Each year, the Japan Neurosurgical Society (JNS) reports up-to-date statistics from the Japan Neurosurgical Database regarding case volume, patient demographics, and in-hospital outcomes of the overall cohort and neurosurgical subgroup according to the major classifications of main diagnosis. We hereby report patient demographics, in-hospital mortality, length of hospital stay, purpose of admission, number of medical management, direct surgery, endovascular treatment, and radiosurgery of the patients based on the major classifications and/or main diagnosis registered in 2018 and 2019 in the overall cohort (523283 and 571143 patients, respectively) and neurosurgical subgroup (177184 and 191595 patients, respectively). The patient demographics, disease severity, proportion of purpose of admission (e.g., operation, 33.9-33.5%) and emergent admission (68.4-67.8%), and in-hospital mortality (e.g., cerebrovascular diseases, 6.3-6.5%; brain tumor, 3.1-3%; and neurotrauma, 4.3%) in the overall cohort were comparable between 2018 and 2019. In total, 207783 and 225217 neurosurgical procedures were performed in the neurosurgical subgroup in 2018 and 2019, respectively, of which endovascular treatment comprised 19.1% and 20.3%, respectively. Neurosurgical management of chronic subdural hematoma (19.4-18.9%) and cerebral aneurysm (15.4-14.8%) was most common. Notably, the proportion of management of ischemic stroke/transient ischemic attack, including recombinant tissue plasminogen activator infusion and endovascular acute reperfusion therapy, increased from 7.5% in 2018 to 8.8% in 2019. The JNS statistical update represents a critical resource for the lay public, policy makers, media professionals, neurosurgeons, healthcare administrators, researchers, health advocates, and others seeking the best available data on neurosurgical practice.

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.

Unruptured aneurysms: Why observational studies fall short no matter how "Big" the Data

BACKGROUND

The best management of unruptured intracranial aneurysms (UIAs) remains unknown, despite multiple observational studies. A randomized trial (RCT) is in order. Yet, a National Institute Neurological Disorders and Stroke workshop has once again proposed to use prospective observational studies (POS) of large databases to address such problems.

METHODS

We review the historical misconceptions that have been associated with observations of UIAs and their treatments. We critically examine some recent methods that have been proposed to address shortcomings of observational studies. We finally review the ethical principles underlying the use of trial methods in the care of patients.

RESULTS

Replacing RCTs with POS submits patients to management options that have never been proven beneficial, while making them involuntary research subjects of studies that are inevitably biased. A science of practice cannot be an outsider's examination of the behavior of clinicians incapable of questioning their practice. The thesis we propose is that a science of practice must not only eventually determine what best practice will be; It must engage agents involved in medical practice to transparently reveal the uncertainty that calls for management options to be offered under the guidance of declared and controlled care research, to optimize patient outcomes in spite of the uncertainty.

CONCLUSION

To use POS rather than RCTs in medical practice is to renege on scientific and ethical principles that characterize modern medicine. Instead, we must learn to integrate care research into our practice to provide optimal medical care in real time.

Measuring clinical uncertainty and equipoise by applying the agreement study methodology to patient management decisions

Background

Clinical uncertainty and equipoise are vague notions that play important roles in contemporary problems of medical care and research, including the design and conduct of pragmatic trials. Our goal was to show how the reliability study methods normally used to assess diagnostic tests can be applied to particular management decisions to measure the degree of uncertainty and equipoise regarding the use of rival management options.

Methods

We first use thrombectomy in acute stroke as an illustrative example of the method we propose. We then review, item by item, how the various design elements of diagnostic reliability studies can be modified in order to measure clinical uncertainty.

Results

The thrombectomy example shows sufficient disagreement and uncertainty to warrant the conduct of additional randomized trials. The general method we propose is that a sufficient number of diverse individual cases sharing a similar clinical problem and covering a wide spectrum of clinical presentations be assembled into a portfolio that is submitted to a variety of clinicians who routinely manage patients with the clinical problem.

Discussion

Clinicians are asked to independently choose one of the predefined management options, which are selected from those that would be compared within a randomized trial that would address the clinical dilemma. Intra-rater agreement can be assessed at a later time with a second evaluation. Various professional judgments concerning individual patients can then be compared and analyzed using kappa statistics or similar methods. Interpretation of results can be facilitated by providing examples or by translating the results into clinically meaningful summary sentences.

Conclusions

Measuring the uncertainty regarding management options for clinical problems may reveal substantial disagreement, provide an empirical foundation for the notion of equipoise, and inform or facilitate the design/conduct of clinical trials to address the clinical dilemma.

Stereotactic Laser Ablation for Mesial Temporal Lobe Epilepsy: A prospective, multicenter, single-arm study

Objective

To describe the development of the Stereotactic Laser Ablation for Temporal Lobe Epilepsy study protocol in the context of current practice. An ideal treatment for drug‐resistant epilepsy remains an ongoing area of research. Although there are several options available, each has challenges that not only make deciding on the appropriate treatment not clear‐cut but also create difficulties in designing clinical studies to provide evidence in support of the treatment.

Methods

A prospective, single‐arm, multicenter study designed to evaluate safety and efficacy of the Visualase^TM MRI‐Guided Laser Ablation System for the treatment of temporal lobe epilepsy will include up to 150 patients with a primary efficacy endpoint of seizure freedom (defined as Engel Class I) for the first 12 months following the procedure and a primary safety endpoint of incidence of qualifying device‐, procedure‐, or anesthesia‐related adverse events through 12 months following the procedure.

Results

Primary endpoints will be assessed against historical values of safety and efficacy of anterior temporal lobectomy.

Significance

The scientific and payor communities typically demand randomized controlled trials (RCTs) as definitive evidence for safety and efficacy claims. However, in circumstances where the medical device has already been cleared by regulatory authorities and is readily available in the market, an RCT may not be feasible to execute. It is therefore crucial to gain acceptance by both the scientific community and regulators to design a study that will satisfy all concerned.

Can We Justify It? Trends in the Utilization of Spinal Fusions and Associated Reimbursement

BACKGROUND

Previous reports have suggested an increasing rate of utilization of spinal fusions, but contemporary data have not been analyzed, and there has been little investigation of putative drivers of increased utilization.

OBJECTIVE

To investigate whether there is an ongoing trend of increased utilization of spinal fusions in recent data, and if there may be associations with an increasing proportion of elderly in the population, changing patterns of payer-types, and changing reimbursement rates.

METHODS

We analyze 7.1 million cases from the National Inpatient Sample between 1998 and 2014. We measure annual utilization per 100 000 persons and conduct trend analyses with subgroup analysis of the senior (65 + ) population. Spine surgery utilization is compared with nonspine surgical procedures (coronary artery bypass grafting, hernia repair, hip, and knee replacement). We assess trends in charges, payer type, Medicare reimbursement rates, and hospital type.

RESULTS

There was an 88% increase in the utilization rate of spinal fusion procedures from 1998 to 2014 (from 74 to 139 cases per 100 000 persons) with a significant upward trend (P < .001) that persisted in the 65 + subgroup (P < .001). An increasing proportion of spinal fusions is paid for by public payers, but per-procedure reimbursement for spinal fusions by Medicare has decreased recently (5% reduction from 2014 to 2016).

CONCLUSION

Utilization of spinal fusions continues to increase and is not explained by increased proportion of elderly in the population, increased utilization of surgeries across specialties, or increased Medicare reimbursement. In fact, increased utilization of spinal fusions temporally correlated with decreasing per-procedure Medicare reimbursement.

How Can We Guide Patient Choice Between "Minimally Invasive" Radiosurgery Versus Resective Epilepsy Surgery?

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Variation in the management of isolated craniosynostosis: a survey of the Synostosis Research Group

OBJECTIVEThe authors created a collaborative network, the Synostosis Research Group (SynRG), to facilitate multicenter clinical research on craniosynostosis. To identify common and differing practice patterns within the network, they assessed the SynRG surgeons' management preferences for sagittal synostosis. These results will be incorporated into planning cooperative studies.METHODSThe SynRG consists of 12 surgeons at 5 clinical sites. An email survey was distributed to SynRG surgeons in late 2016, and responses were collected through early 2017. Responses were collated and analyzed descriptively.RESULTSAll of the surgeons-7 plastic/craniofacial surgeons and 5 neurosurgeons-completed the survey. They varied in both experience (1-24 years) and sagittal synostosis case volume in the preceding year (5-45 cases). Three sites routinely perform preoperative CT scans. The preferred surgical technique for children younger than 3 months is strip craniectomy (10/12 surgeons), whereas children older than 6 months are all treated with open cranial vault surgery. Pre-incision cefazolin, preoperative complete blood count panels, and an arterial line were used by most surgeons, but tranexamic acid was used routinely at 3 sites and never at the other 2 sites. Among surgeons performing endoscopic strip craniectomy surgery (SCS), most create a 5-cm-wide craniectomy, whereas 2 surgeons create a 2-cm strip. Four surgeons routinely send endoscopic SCS patients to the intensive care unit after surgery. Two of the 5 sites routinely obtain a CT scan within the 1st year after surgery.CONCLUSIONSThe SynRG surgeons vary substantially in the use of imaging, the choice of surgical procedure and technique, and follow-up. A collaborative network will provide the opportunity to study different practice patterns, reduce variation, and contribute multicenter data on the management of children with craniosynostosis.

Occipital Nerve Stimulation for the Treatment of Refractory Occipital Neuralgia: A Case Series

BACKGROUND

Occipital neuralgia is a chronic pain syndrome characterized by sharp, shooting pains in the distribution of the occipital nerves. Although relatively rare, it associated with extremely debilitating symptoms that drastically affect a patient's quality of life. Furthermore, it is extremely difficult to treat as the symptoms are refractory to traditional treatments, including pharmacologic and procedural interventions. A few previous case studies have established the use of a neurostimulation of the occipital nerves to treat occipital neuralgia.

OBJECTIVE

The following expands on that literature by retrospectively reviewing the results of occipital nerve stimulation in a relatively large patient cohort (29 patients).

METHODS

A retrospective review of 29 patients undergoing occipital nerve stimulation for occipital neuralgia from 2012 to 2017 at a single institution with a single neurosurgeon.

RESULTS

Of those 29 patients, 5 were repair or replacement of previous systems, 4 did not have benefit from trial stimulation, and 20 saw benefit to their trial stage of stimulation and went on to full implantation. Of those 20 patients, even with a history of failed procedures and pharmacological therapies, there was an overall success rate of 85%. The average preoperative 10-point pain score dropped from 7.4 ± 1.7 to a postoperative score of 2.9 ± 1.7. However, as with any peripheral nerve stimulation procedure, there were complications (4 patients), including infection, hardware erosion, loss of effect, and lead migration, which required revision or system removal.

CONCLUSION

Despite complications, the results suggest, overall, that occipital nerve stimulation is a safe and effective procedure for refractory occipital neuralgia and should be in the neurosurgical repertoire for occipital neuralgia treatment.