The design of the Canadian UnRuptured Endovascular versus Surgery (CURES) trial

A Pragmatic Randomized Trial Comparing Surgical Clipping and Endovascular Treatment of Unruptured Intracranial Aneurysms

BACKGROUND AND PURPOSE

Surgical clipping and endovascular treatment are commonly used in patients with unruptured intracranial aneurysms. We compared the safety and efficacy of the 2 treatments in a randomized trial.

MATERIALS AND METHODS

Clipping or endovascular treatments were randomly allocated to patients with one or more 3- to 25-mm unruptured intracranial aneurysms judged treatable both ways by participating physicians. The study hypothesized that clipping would decrease the incidence of treatment failure from 13% to 4%, a composite primary outcome defined as failure of aneurysm occlusion, intracranial hemorrhage during follow-up, or residual aneurysms at 1 year, as adjudicated by a core lab. Safety outcomes included new neurologic deficits following treatment, hospitalization of >5 days, and overall morbidity and mortality (mRS > 2) at 1 year. There was no blinding.

RESULTS

Two hundred ninety-one patients were enrolled from 2010 to 2020 in 7 centers. The 1-year primary outcome, ascertainable in 290/291 (99%) patients, was reached in 13/142 (9%; 95% CI, 5%-15%) patients allocated to surgery and in 28/148 (19%; 95% CI, 13%-26%) patients allocated to endovascular treatments (relative risk: 2.07; 95% CI, 1.12-3.83; P = .021). Morbidity and mortality (mRS >2) at 1 year occurred in 3/143 and 3/148 (2%; 95% CI, 1%-6%) patients allocated to surgery and endovascular treatments, respectively. Neurologic deficits (32/143, 22%; 95% CI, 16%-30% versus 19/148, 12%; 95% CI, 8%-19%; relative risk: 1.74; 95% CI, 1.04-2.92; P = .04) and hospitalizations beyond 5 days (69/143, 48%; 95% CI, 40%-56% versus 12/148, 8%; 95% CI, 5%-14%; relative risk: 0.18; 95% CI, 0.11-0.31; P < .001) were more frequent after surgery.

CONCLUSIONS

Surgical clipping is more effective than endovascular treatment of unruptured intracranial aneurysms in terms of the frequency of the primary outcome of treatment failure. Results were mainly driven by angiographic results at 1 year.

Surgical or Endovascular Treatment of MCA Aneurysms: An Agreement Study

BACKGROUND AND PURPOSE

MCA aneurysms are still commonly clipped surgically despite the recent development of a number of endovascular tools and techniques. We measured clinical uncertainty by studying the reliability of decisions made for patients with middle cerebral artery (MCA) aneurysms.

MATERIALS AND METHODS

A portfolio of 60 MCA aneurysms was presented to surgical and endovascular specialists who were asked whether they considered surgery or endovascular treatment to be an option, whether they would consider recruitment of the patient in a randomized trial, and whether they would provide their final management recommendation. Agreement was studied using κ statistics. Intrarater reliability was assessed with the same, permuted portfolio of cases of MCA aneurysm sent to the same specialists 1 month later.

RESULTS

Surgical management was the preferred option for neurosurgeons (n = 844/1320; [64%] responses/22 raters), while endovascular treatment was more commonly chosen by interventional neuroradiologists (1149/1500 [76.6%] responses/25 raters). Interrater agreement was only "slight" for all cases and all judges (κ = 0.094; 95% CI, 0.068-0.130). Agreement was no better within specialties or with more experience. On delayed requestioning, 11 of 35 raters (31%) disagreed with themselves on at least 20% of cases. Surgical management and endovascular treatment were always judged to be a treatment option, for all patients. Trial participation was offered to patients 65% of the time.

CONCLUSIONS

Individual clinicians did not agree regarding the best management of patients with MCA aneurysms. A randomized trial comparing endovascular with surgical management of patients with MCA aneurysms is in order.

European Stroke Organisation (ESO) guidelines on management of unruptured intracranial aneurysms

Unruptured intracranial aneurysms (UIA) occur in around 3% of the population. Important management questions concern if and how to perform preventive UIA occlusion; if, how and when to perform follow up imaging and non-interventional means to reduce the risk of rupture. Using the Standard Operational Procedure of ESO we prepared guidelines according to GRADE methodology. Since no completed randomised trials exist, we used interim analyses of trials, and meta-analyses of observational and case-control studies to provide recommendations to guide UIA management. All recommendations were based on very low evidence. We suggest preventive occlusion if the estimated 5-year rupture risk exceeds the risk of preventive treatment. In general, we cannot recommend endovascular over microsurgical treatment, but suggest flow diverting stents as option only when there are no other low-risk options for UIA repair. To detect UIA recurrence we suggest radiological follow up after occlusion. In patients who are initially observed, we suggest radiological monitoring to detect future UIA growth, smoking cessation, treatment of hypertension, but not treatment with statins or acetylsalicylic acid with the indication to reduce the risk of aneurysm rupture. Additionally, we formulated 15 expert-consensus statements. All experts suggest to assess UIA patients within a multidisciplinary setting (neurosurgery, neuroradiology and neurology) at centres consulting >100 UIA patients per year, to use a shared decision-making process based on the team recommendation and patient preferences, and to repair UIA only in centres performing the proposed treatment in >30 patients with (ruptured or unruptured) aneurysms per year per neurosurgeon or neurointerventionalist. These UIA guidelines provide contemporary recommendations and consensus statement on important aspects of UIA management until more robust data come available.

Flow Diversion in the Treatment of Intracranial Aneurysms: A Pragmatic Randomized Care Trial

BACKGROUND AND PURPOSE

Flow diversion is a recent endovascular treatment for intracranial aneurysms. We compared the safety and efficacy of flow diversion with the alternative standard management options.

MATERIALS AND METHODS

A parallel group, prerandomized, controlled, open-label pragmatic trial was conducted in 3 Canadian centers. The trial included all patients considered for flow diversion. A Web-based platform 1:1 randomly allocated patients to flow diversion or 1 of 4 alternative standard management options (coiling with/without stent placement, parent vessel occlusion, surgical clipping, or observation) as prespecified by clinical judgment. Patients ineligible for alternative standard management options were treated with flow diversion in a registry. The primary safety outcome was death or dependency (mRS > 2) at 3 months. The composite primary efficacy outcome included the core lab-determined angiographic presence of a residual aneurysm, aneurysm rupture, progressive mass effect during follow-up, or death or dependency (mRS > 2) at 3-12 months.

RESULTS

Between May 2011 and November 2020, three hundred twenty-three patients were recruited: Two hundred seventy-eight patients (86%) had treatment randomly allocated (139 to flow diversion and 139 to alternative standard management options), and 45 (14%) received flow diversion in the registry. Patients in the randomized trial frequently had unruptured (83%), large (52% ≥10 mm) carotid (64%) aneurysms. Death or dependency at 3 months occurred in 16/138 patients who underwent flow diversion and 12/137 patients receiving alternative standard management options (relative risk, 1.33; 95% CI, 0.65-2.69; P = .439). A poor primary efficacy outcome was found in 30.9% (43/139) with flow diversion and 45.6% (62/136) of patients receiving alternative standard management options, with an absolute risk difference of 14.7% (95% CI, 3.3%-26.0%; relative risk, 0.68; 95% CI, 0.50-0.92; P = .014).

CONCLUSIONS

For patients with mostly unruptured, large, anterior circulation (carotid) aneurysms, flow diversion was more effective than the alternative standard management option in terms of angiographic outcome.

Understanding the reliability of trial outcome measures: The example of angiographic results of surgical or endovascular treatments of aneurysms

BACKGROUND

The reliability of outcome measures is of central importance in clinical research. Studies of reliability remain rare in the neurovascular field.

METHODS

A narrative review of the history (1997-2021) of reporting angiographic results of the surgical or endovascular treatments of aneurysms serves to illustrate the importance of precisely defining outcome measures. We also review how the reliability of an angiographic classification system was studied.

DISCUSSION

Outcome measures are commonly used without precise definitions. When definitions or classification systems exist, they are rarely verified for their reliability. Twenty-five years following its introduction, a classification of angiographic results of aneurysm treatments is still being studied and modified.

CONCLUSION

The reliability of outcome measures should be made a research priority if we are to practice outcome-based medical or surgical care.

Clinical Trials of Microsurgery for Cerebral Aneurysms: Past and Future

BACKGROUND

New findings and research regarding the microsurgical treatment of intracerebral aneurysms (IAs) continue to advance even in the era of endovascular therapies. Research in the past 2 decades has continued to revolve around the question of whether open surgery or endovascular treatment is preferable. The answer remains both complex and in flux.

OBJECTIVE

This review focuses on microsurgery, reflects on the research decisions of previous landmark studies, and proposes future study designs that may further our understanding of IAs and how best to treat them.

RESULTS

The future of IA research may include a combination of pragmatic trials, artificial intelligence integrated tools, and mining of large data sets, in addition to the publication of high-quality single-center studies.

CONCLUSIONS

The future will likely emphasize testing innovative techniques, looking at granular patient data, and considering every patient encounter as a potential source of knowledge, creating a system in which data are updated daily because each patient interaction contributes to answering important research questions.

Flow Diversion for Middle Cerebral Artery Aneurysms: An International Cohort Study

BACKGROUND

Open surgery has traditionally been preferred for the management of bifurcation middle cerebral artery (MCA) aneurysms. Flow diverting stents present a novel endovascular strategy for aneurysm treatment.

OBJECTIVE

To add to the limited literature describing the outcomes and complications in the use of flow diverters for the treatment of these complex aneurysms.

METHODS

This is a multicenter retrospective review of MCA bifurcation aneurysms undergoing flow diversion. We assessed post-treatment radiological outcomes and both thromboembolic and hemorrhagic complications.

RESULTS

We reviewed the outcomes of 54 aneurysms treated with flow diversion. Four (7.4%) of the aneurysms had a history of rupture (3 remote and 1 acute). Fourteen (25.9%) of the aneurysms already underwent either open surgery or coiling prior to flow diversion. A total of 36 out of the 45 aneurysms (80%) with available follow-up data had adequate aneurysm occlusion with a median follow-up time of 12 mo. There were no hemorrhagic complications but 16.7% (9/54) had thromboembolic complications.

CONCLUSION

Flow diverting stents may be a viable option for the endovascular treatment of complex bifurcation MCA aneurysms. However, compared to published series on the open surgical treatment of this subset of aneurysms, flow diversion has inferior outcomes and are associated with a higher rate of complications.

Angiographic results of surgical or endovascular treatment of intracranial aneurysms: a systematic review and inter-observer reliability study

PURPOSE

Results of surgical or endovascular treatment of intracranial aneurysms are often assessed using angiography. A reliable method to report results irrespective of treatment modality is needed to enable comparisons. Our goals were to systematically review existing classification systems, and to propose a 3-point classification applicable to both treatments and assess its reliability.

METHODS

We conducted two systematic reviews on classification systems of angiographic results after clipping or coiling to select a simple 3-category scale that could apply to both treatments. We then circulated an electronic portfolio of angiograms of clipped (n=30) or coiled (n=30) aneurysms, and asked raters to evaluate the degree of occlusion using this scale. Raters were also asked to choose an appropriate follow-up management for each patient based on the degree of occlusion. Agreement was assessed using Krippendorff's α statistics (α_K), and relationship between occlusion grade and clinical management was analyzed using Fisher's exact and Cramer's V tests.

RESULTS

The systematic reviews found 70 different grading scales with heterogeneous reliability (kappa values from 0.12 to 1.00). The 60-patient portfolio was independently evaluated by 19 raters of diverse backgrounds (neurosurgery, radiology, and neurology) and experience. There was substantial agreement (α_K=0.76, 95%CI, 0.67-0.83) between raters, regardless of background, experience, or treatment used. Intra-rater agreement ranged from moderate to almost perfect. A strong relationship was found between angiographic grades and management decisions (Cramer's V: 0.80±0.12).

CONCLUSION

A simple 3-point scale demonstrated sufficient reliability to be used in reporting aneurysm treatments or in evaluating treatment results in comparative randomized trials.

Surgical or Endovascular Management of Middle Cerebral Artery Aneurysms: A Randomized Comparison

OBJECTIVE

There are few randomized data comparing clipping and coiling for middle cerebral artery (MCA) aneurysms. We analyzed results from patients with MCA aneurysms enrolled in the CURES (Collaborative UnRuptured Endovascular vs. Surgery) and ISAT-2 (International Subarachnoid Aneurysm Trial II) randomized trials.

METHODS

Both trials are investigator-led parallel-group 1:1 randomized studies. CURES includes patients with 3-mm to 25-mm unruptured intracranial aneurysms (UIAs), and ISAT-2 includes patients with ruptured aneurysms (RA) for whom uncertainty remains after ISAT. The primary outcome measure of CURES is treatment failure: 1) failure to treat the aneurysm, 2) intracranial hemorrhage during follow-up, or 3) residual aneurysm at 1 year. The primary outcome of ISAT-2 is death or dependency (modified Rankin Scale score >2) at 1 year. One-year angiographic outcomes are systematically recorded.

RESULTS

There were 100 unruptured and 71 ruptured MCA aneurysms. In CURES, 90 patients with UIA have been treated and 10 await treatment. Surgical and endovascular management of unruptured MCA aneurysms led to treatment failure in 3/42 (7%; 95% confidence interval [CI], 0.02-0.19) for clipping and 13/48 (27%; 95% CI, 0.17-0.41) for coiling (P = 0.025). All 71 patients with RA have been treated. In ISAT-2, patients with ruptured MCA aneurysms managed surgically had died or were dependent (modified Rankin Scale score >2) in 7/38 (18%; 95% CI, 0.09-0.33) cases, and 8/33 (24%; 95% CI, 0.13-0.41) for endovascular. One-year imaging results were available in 80 patients with UIA and 62 with RA. Complete aneurysm occlusion was found in 30/40 (75%; 95% CI, 0.60-0.86) patients with UIA allocated clipping, and 14/40 (35%; 95% CI, 0.22-0.50) patients with UIA allocated coiling. Complete aneurysm occlusion was found in 24/34 (71%; 95% CI, 0.54-0.83) patients with RA allocated clipping, and 15/28 (54%; 95% CI, 0.36-0.70) patients with RA allocated coiling.

CONCLUSIONS

Randomized data from 2 trials show that better efficacy may be obtained with surgical management of patients with MCA aneurysms.

Practicing outcome-based medical care using pragmatic care trials

The current separation between medical research and care is an obstacle to essential aspects of good medical practice: the verification that care interventions actually deliver the good outcomes they promise, and the use of scientific methods to optimize care under uncertainty. Pragmatic care trials have been designed to address these problems. Care trials are all-inclusive randomized trials integrated into care. Every item of trial design is selected in the best medical interest of participating patients. Care trials can eventually show what constitutes good medical practice based on patient outcomes. In the meantime, care trials give clinicians and patients the scientific methods necessary for optimization of medical care when no one really knows what to do.We report the progress of 9 randomized care trials that were used to guide the endovascular or surgical management of 1212 patients with acute stroke, intracranial aneurysms, and arteriovenous malformations in a single center in an elective or acute care context. Care trials were used to address long-standing dilemmas regarding rival medical, surgical, or endovascular management options or to offer innovative instead of standard treatments. The trial methodology, by replacing unrepeatable treatment decisions by 1:1 randomized allocation whenever reliable knowledge was not available, had an immediate impact, transforming unverifiable dogmatic medical practice into verifiable outcome-based medical care. We believe the approach is applicable to all medical or surgical domains, but widespread adoption may require the revision of many currently prevalent views regarding the role of research in clinical practice.

Comprehensive Aneurysm Management (CAM): An All-Inclusive Care Trial for Unruptured Intracranial Aneurysms

BACKGROUND

In the absence of randomized evidence, the optimal management of patients with unruptured intracranial aneurysms (UIA) remains uncertain.

METHODS

Comprehensive Aneurysm Management (CAM) is an all-inclusive care trial combined with a registry. Any patient with a UIA (no history of intracranial hemorrhage within the previous 30 days) can be recruited, and treatment allocation will follow an algorithm combining clinical judgment and randomization. Patients eligible for at least 2 management options will be randomly allocated 1:1 to conservative or curative treatment. Minimization will be used to balance risk factors, using aneurysm size (≥7 mm), location (anterior or posterior circulation), and age <60 years.

RESULTS

The CAM primary outcome is survival without neurologic dependency (modified Rankin Scale [mRS] score <3) at 10 years. Secondary outcome measures include the incidence of subarachnoid hemorrhage during follow-up and related morbidity and mortality; morbidity and mortality related to endovascular treatment or surgical treatment of the UIA at 1 year; overall morbidity and mortality at 1, 5, and 10 years; when relevant, duration of hospitalization; and, when relevant, discharge to a location other than home. The primary hypothesis for patients randomly allocated to at least 2 options, 1 of which is conservative management, is that active UIA treatment will reduce the 10-year combined neurologic morbidity and mortality (mRS score >2) from 24% to 16%. At least 961 patients recruited from at least 20 centers over 4 years will be needed for the randomized portion of the study.

CONCLUSIONS

Patients with unruptured intracranial aneurysms can be comprehensively managed within the context of an all-inclusive care trial.

Reporting Interim Results Can Show the Feasibility of Practicing Outcome-Based Neurovascular Care Within Randomized Trials: An Opinion

BACKGROUND

Randomized trials of commonly performed surgical interventions are notoriously difficult to conduct. The trial methodology may nevertheless be the best way to offer outcome-based neurovascular care in the presence of uncertainty. One obstacle to promoting such trials is the conventional prohibition of publication and dissemination of interim results as the trial progresses.

METHODS

We review the scientific and statistical reasons against the publication of interim analyses as well as exceptions that can occur when 1 treatment is unexpectedly shown to be harmful or when the results of other trials have convincingly shown the comparative benefits of a new intervention. We also discuss the promotion of difficult surgical trials.

RESULTS

Reasons to support the conventional ban on publication of interim results include control of statistical errors, prevention of invalid conclusions, and dissemination of false claims of equivalence of rival interventions. In the early phases of a trial, usually 1 treatment cannot be shown superior to the other. We believe, contrary to the received view, that a transparent report of the early progress of certain trials can be justified, even when interim results are inconclusive, to promote the recruitment of participating centers and the practice of a novel way to offer neurovascular care in the presence of uncertainty in the best medical interest of patients.

CONCLUSIONS

In our opinion, the early publication of inconclusive interim results may increase awareness of the feasibility of surgical care trials.

Indications for the Performance of Intracranial Endovascular Neurointerventional Procedures: A Scientific Statement From the American Heart Association

Intracranial endovascular interventions provide effective and minimally invasive treatment of a broad spectrum of diseases. This area of expertise has continued to gain both wider application and greater depth as new and better techniques are developed and as landmark clinical studies are performed to guide their use. Some of the greatest advances since the last American Heart Association scientific statement on this topic have been made in the treatment of ischemic stroke from large intracranial vessel occlusion, with more effective devices and large randomized clinical trials showing striking therapeutic benefit. The treatment of cerebral aneurysms has also seen substantial evolution, increasing the number of aneurysms that can be treated successfully with minimally invasive therapy. Endovascular therapies for such other diseases as arteriovenous malformations, dural arteriovenous fistulas, idiopathic intracranial hypertension, venous thrombosis, and neoplasms continue to improve. The purpose of the present document is to review current information on the efficacy and safety of procedures used for intracranial endovascular interventional treatment of cerebrovascular diseases and to summarize key aspects of best practice.

Management of Unruptured Intracranial Aneurysms

Unruptured intracranial aneurysms (UIA) occur in approximately 2-3 % of the population. Most of these lesions are incidentally found, asymptomatic and typically carry a benign course. Although the risk of aneurysmal subarachnoid hemorrhage is low, this complication can result in significant morbidity and mortality, making assessment of this risk the cornerstone of UIA management. This article reviews important factors to consider when managing unruptured intracranial aneurysms including patient demographics, comorbidities, family history, symptom status, and aneurysm characteristics. It also addresses screening, monitoring, medical management and current surgical and endovascular therapies.

Surgical clipping or endovascular coiling for unruptured intracranial aneurysms: a pragmatic randomised trial

BACKGROUND

Unruptured intracranial aneurysms (UIAs) are increasingly diagnosed and are commonly treated using endovascular treatment or microsurgical clipping. The safety and efficacy of treatments have not been compared in a randomised trial. How to treat patients with UIAs suitable for both options remains unknown.

METHODS

We randomly allocated clipping or coiling to patients with one or more 3-25 mm UIAs judged treatable both ways. The primary outcome was treatment failure, defined as: initial failure of aneurysm treatment, intracranial haemorrhage or residual aneurysm on 1-year imaging. Secondary outcomes included neurological deficits following treatment, hospitalisation >5 days, overall morbidity and mortality and angiographic results at 1 year.

RESULTS

The trial was designed to include 260 patients. An analysis was performed for slow accrual: 136 patients were enrolled from 2010 through 2016 and 134 patients were treated. The 1-year primary outcome, available for 104 patients, was reached in 5/48 (10.4% (4.5%-22.2%)) patients allocated surgical clipping, and 10/56 (17.9% (10.0%-29.8%)) patients allocated endovascular coiling (OR: 0.54 (0.13-1.90), p=0.40). Morbidity and mortality (modified Rankin Scale>2) at 1 year occurred in 2/48 (4.2% (1.2%-14.0%)) and 2/56 (3.6% (1.0%-12.1%)) patients allocated clipping and coiling, respectively. New neurological deficits (15/65 vs 6/69; OR: 3.12 (1.05-10.57), p=0.031), and hospitalisations beyond 5 days (30/65 vs 6/69; OR: 8.85 (3.22-28.59), p=0.0001) were more frequent after clipping.

CONCLUSION

Surgical clipping or endovascular coiling of UIAs did not show differences in morbidity at 1 year. Trial continuation and additional randomised evidence will be necessary to establish the supposed superior efficacy of clipping.

Hydrogel versus Bare Platinum Coils in Patients with Large or Recurrent Aneurysms Prone to Recurrence after Endovascular Treatment: A Randomized Controlled Trial

BACKGROUND AND PURPOSE

Some patients are at high risk of aneurysm recurrence after endovascular treatment: patients with large aneurysms (Patients Prone to Recurrence After Endovascular Treatment PRET-1) or with aneurysms that have previously recurred after coiling (PRET-2). We aimed to establish whether the use of hydrogel coils improved efficacy outcomes compared with bare platinum coils.

MATERIALS AND METHODS

PRET was an investigator-led, pragmatic, multicenter, parallel, randomized (1:1) trial. Randomized allocation was performed separately for patients in PRET-1 and PRET-2, by using a Web-based platform ensuring concealed allocation. The primary outcome was a composite of a residual/recurrent aneurysm, adjudicated by a blinded core laboratory, or retreatment, intracranial bleeding, or mass effect during the 18-month follow-up. Secondary outcomes included adverse events, mortality, and morbidity (mRS > 2). The hypothesis was that hydrogel would decrease the primary outcome from 50% to 30% at 18 months, necessitating 125 patients per group (500 for PRET-1 and PRET-2).

RESULTS

The trial was stopped once 250 patients in PRET-1 and 197 in PRET-2 had been recruited because of slow accrual. A poor primary outcome occurred in 44.4% (95% CI, 35.5%-53.2%) of those in PRET-1 allocated to platinum compared with 52.5% (95% CI, 43.4%-61.6%) of patients allocated to hydrogel (OR, 1.387; 95% CI, 0.838-2.295; P = .20) and in 49.0% (95% CI, 38.8%-59.1%) in PRET-2 allocated to platinum compared with 42.1% (95% CI, 32.0%-52.2%) allocated to hydrogel (OR, 0.959; 95% CI, 0.428-1.342; P = .34). Adverse events and morbidity were similar. There were 3.6% deaths (1.4% platinum, 5.9% hydrogel; P = .011).

CONCLUSIONS

Coiling of large and recurrent aneurysms is safe but often poorly effective according to angiographic results. Hydrogel coiling was not shown to be better than platinum.

Treatment of unruptured intracranial aneurysms: a review

INTRODUCTION

Unruptured brain aneurysms (UIAs) present a challenge due to the lack of definitive understanding of their natural history and treatment outcomes. As the treatment of UIAs is aimed at preventing the possibility of rupture, the immediate risk of treatment must be weighed against the risk of rupture in the future. As such, treatment for a large proportion of UIAs is currently individualized.

AREAS COVERED

In this article, we discuss the important natural history studies of UIAs and discuss the existing scientific evidence and recent advances that help identify the rupture risk guide management of UIAs. We also address the recent advances in pharmacological therapy of UIAs. Expert commentary: In the recent years, there have been great advances in understanding the pathophysiology of UIAs and determining the rupture risk going beyond the traditional parameter of aneurysm size. Aneurysm morphology and hemodynamics play a pivotal role in growth and rupture. A true randomized trial for the management of UIAs is the need of the hour.

Inter- and Intrarater Agreement on the Outcome of Endovascular Treatment of Aneurysms Using MRA

BACKGROUND AND PURPOSE

Patients treated with coiling are often followed by MR angiography. Our objective was to assess the inter- and intraobserver agreement in diagnosing aneurysm remnants and recurrences by using multimodality imaging, including TOF MRA.

MATERIALS AND METHODS

A portfolio composed of 120 selected images from 56 patients was sent to 15 neuroradiologists from 10 institutions. For each case, raters were asked to classify angiographic results (3 classes) of 2 studies (32 MRA-MRA and 24 DSA-MRA pairs) and to provide a final judgment regarding the presence of a recurrence (no, minor, major). Six raters were asked to independently review the portfolio twice. A second study, restricted to 4 raters having full access to all images, was designed to validate the results of the electronic survey.

RESULTS

The proportion of cases judged to have a major recurrence varied between 16.1% and 71.4% (mean, 35.0% ± 12.7%). There was moderate agreement overall (κ = 0.474 ± 0.009), increasing to nearly substantial (κ = 0.581 ± 0.014) when the judgment was dichotomized (presence or absence of a major recurrence). Agreement on cases followed-up by MRA-MRA was similarly substantial (κ = 0.601 ± 0.018). The intrarater agreement varied between fair (κ = 0.257 ± 0.093) and substantial (κ= 0.699 ± 0.084), improving with a dichotomized judgment concerning MRA-MRA comparisons. Agreement was no better when raters had access to all images.

CONCLUSIONS

There is an important variability in the assessment of angiographic outcomes of endovascular treatments. Agreement on the presence of a major recurrence when comparing 2 MRA studies or the MRA with the last catheter angiographic study can be substantial.

Comparison of the Efficacy and Safety of Endovascular Coiling Versus Microsurgical Clipping for Unruptured Middle Cerebral Artery Aneurysms: A Systematic Review and Meta-Analysis

OBJECTIVE

Middle cerebral artery aneurysms (MCAAs) are regularly treated by both microsurgical clipping and endovascular coiling. We performed a systematic meta-analysis to compare the safety and efficacy of these 2 methods.

METHODS

Literature was reviewed for all studies reporting angiographic occlusion and/or functional outcomes in adults with unruptured MCAA treated by endovascular coiling or microsurgical clipping. All studies in English that reported results for adults (≥18 years) with unruptured MCAAs, from 1990 to 2011 were considered for inclusion.

RESULTS

Twenty-six studies involving 2295 aneurysms treated with clipping or coiling for unruptured MCAAs were included for analysis. There were 1530 aneurysms that were treated with clipping and 765 aneurysms treated with coiling. Pooled analysis revealed failure of aneurysmal occlusion in 3.0% (95% confidence interval [CI] 1.2%-7.4%) of clipped cases. Pooled analysis of 15 studies (606 aneurysms) involving coiling and occlusion revealed lack of occlusion rates of 47.7% (95% CI 43.6%-51.8%) with the fixed-effects model and 48.2% (95% CI 39.0%-57.4%) with the random-effects model. Thirteen studies examined neurological outcomes after clipping and were pooled for analysis. Both fixed-effect and random-effect models revealed unfavorable outcomes in 2.1% (95% CI 1.3%-3.3%) of patients. There were 17 studies evaluating potential unfavorable neurological outcomes after coiling that were pooled for analysis. Fixed-effect and random-effect models revealed unfavorable outcomes in 6.5% (95% CI 4.5%-9.3%) and 4.9% (95% CI 3.0%-8.1%) of patients, respectively.

CONCLUSIONS

Based on this systematic review and meta-analysis of unruptured MCAAs, after careful consideration of patient, aneurysmal, and treatment center factors, we recommend surgical clipping for unruptured MCAA.

Guidelines for the Management of Patients With Unruptured Intracranial Aneurysms: A Guideline for Healthcare Professionals From the American Heart Association/American Stroke Association

PURPOSE

The aim of this updated statement is to provide comprehensive and evidence-based recommendations for management of patients with unruptured intracranial aneurysms.

METHODS

Writing group members used systematic literature reviews from January 1977 up to June 2014. They also reviewed contemporary published evidence-based guidelines, personal files, and published expert opinion to summarize existing evidence, indicate gaps in current knowledge, and when appropriate, formulated recommendations using standard American Heart Association criteria. The guideline underwent extensive peer review, including review by the Stroke Council Leadership and Stroke Scientific Statement Oversight Committees, before consideration and approval by the American Heart Association Science Advisory and Coordinating Committee.

RESULTS

Evidence-based guidelines are presented for the care of patients presenting with unruptured intracranial aneurysms. The guidelines address presentation, natural history, epidemiology, risk factors, screening, diagnosis, imaging and outcomes from surgical and endovascular treatment.

Pragmatic trials can be designed as optimal medical care: principles and methods of care trials

OBJECTIVES

The way clinical research and care are currently separated encourages the practice of unverifiable medicine. Some pragmatic trials can be designed (1) to guide proper medical conduct in the presence of uncertainty and (2) to govern the distinction between unvalidated and validated care.

METHODS

Care trials are simple randomized trials integrated into a practice they regulate in the interest of present patients. The fundamental principle guiding the design of a care trial is the protection of the patient being offered medical care that has not yet been validated. Selection criteria are inclusive, to assist most current patients confronted with the problem. The trial entails no extra tests or risks beyond what is proven beneficial. Endpoints are pre-defined, simple, valuable and resistant to bias. Follow-up visits and tests are routine. Data is collected in simple case-report forms.

RESULTS

Care trials protect present patients from both unverifiable medicine and research performed for extraneous interests. They provide prudent care when evidence is lacking. They should not be obstructed by the need for separate funding, or by bureaucracy.

CONCLUSION

Care trials can identify which medical alternative should be standard therapy. In the meantime, they provide optimal care in the presence of uncertainty.

Patients prone to recurrence after endovascular treatment: periprocedural results of the PRET randomized trial on large and recurrent aneurysms

BACKGROUND AND PURPOSE

Some patients with large or recurrent aneurysms may be at increased risk of recurrence postcoiling. The Patients Prone to Recurrence after Endovascular Treatment (PRET) trial was designed to assess whether hydrogel coils were superior to platinum coils in these high-risk patients. This article reports periprocedural safety and operator-assessed angiographic results from the PRET trial.

MATERIALS AND METHODS

PRET was a pragmatic, multicenter, randomized controlled trial. Patients had ≥10-mm aneurysms (PRET-1) or a major recurrence after coiling of an aneurysm of any size (PRET-2). Patients were randomly allocated to hydrogel or control arms (any platinum coil) by using concealed allocation with minimization. Assist devices could be used as clinically required. Aneurysms could be unruptured or recently ruptured. Analyses were on an intent-to-treat basis.

RESULTS

Four hundred forty-seven patients were recruited (250 PRET-1; 197 PRET-2). Aneurysms were recently ruptured in 29% of PRET-1 and 4% of PRET-2 patients. Aneurysms were ≥10 mm in all PRET-1 and in 50% of PRET-2 patients. They were wide-neck (≥4 mm) in 70% and in the posterior circulation in 24% of patients. Stents were used in 28% of patients (35% in PRET-2). Coiling was successful in 98%. Adverse events occurred in 28 patients with hydrogel and 23 with platinum coils. Mortality (n=2, unrelated to treatment) and morbidity (defined as mRS>2 at 1 month) occurred in 25 patients (5.6%; 12 hydrogel, 13 platinum), related to treatment in 10 (4 hydrogel; 6 platinum) (or 2.3% of 444 treated patients). No difference was seen between hydrogel and platinum for any of the indices used to assess safety up to at least 30 days after treatment. At 1 month, 95% of patients were home with a good outcome (mRS≤2 or unchanged). Operator-assessed angiographic outcomes were satisfactory (complete occlusion or residual neck) in 339 of 447 or 76.4% of patients, with no significant difference between groups.

CONCLUSIONS

Endovascular treatment of large and recurrent aneurysms can be performed safely with platinum or hydrogel coils.

Uncertainty and agreement in the management of unruptured intracranial aneurysms

OBJECT

The management of unruptured intracranial aneurysms remains controversial. The goal of this study was to evaluate the clinical community agreement in decision making regarding unruptured intracranial aneurysms.

METHODS

A portfolio of 41 cases of unruptured intracranial aneurysms with angiographic images, along with a short description of the patient presentation, was sent to 28 clinicians (16 radiologists and 12 surgeons) with varying years of experience in the management of unruptured intracranial aneurysms. Five senior clinicians responded twice at least 3 months apart. Nineteen cases (46%) were selected from patients recruited in the Canadian UnRuptured Endovascular versus Surgery trial, an ongoing randomized comparison of coil embolization and clip placement. For each case, the responder was to first choose between 3 treatment options (observation, surgical clip placement, or endovascular coil embolization) and then indicate their level of certainty on a quantitative 0-10 scale. Agreement in decision making was studied using κ statistics.

RESULTS

Decisions to coil were more frequent (n = 612, 53%) than decisions to clip (n = 289, 25%) or to observe (n = 259, 22%). Interjudge agreement was only fair (κ = 0.31 ± 0.02) for all cases and all judges, despite substantial intrajudge agreement (range 0.44-0.83 ± 0.10), with high mean individual certainty levels for each case (range 6.5-9.4 ± 2.0 on a scale of 0-10). Agreement was no better within specialties (surgeons or radiologists), within capability groups (those able to perform endovascular coiling alone, surgical clipping alone, or both), or with more experience. There was no correlation between certainty levels and years of experience. Agreement was lower when the cases were taken from the randomized trial (κ = 0.19 ± 0.2) compared with nontrial cases (κ = 0.35 ± 0.2).

CONCLUSIONS

Individuals do not agree regarding the management of unruptured intracranial aneurysms, even when they share a background in the same specialty, similar capabilities in aneurysm management, or years of practice. If community equipoise is a necessary precondition for trial participation, this study has found sufficient uncertainty and disagreement among clinicians to justify randomized trials.

Surgery for unruptured intracranial aneurysms in the ISAT and ISUIA era

BACKGROUND

The ISAT and ISUIA studies, along with the improvement of endovascular treatment (EVT) have strongly influenced the management of intracranial aneurysms (IAs). We present our experience in the microsurgical treatment of unruptured IAs (UIAs) in this context.

METHODS

We retrospectively reviewed a consecutive series of non-giant UIAs selected for surgery during a five-year period. Patients and aneurysms characteristics, surgical results and outcome assessed by the Glascow Outcome Scale (GOS) at three month follow-up were studied.

RESULTS

Eighty-five patients underwent 93 surgical procedures to obliterate 113 UIAs. Those were incidental in 89% of the cases and mainly located on the middle cerebral artery (65%). Patients were assigned to surgery according to their medical history (young, previous subarachnoid haemorrhage), aneurysm characteristics (wide neck, branch at the neck, "small" size, associated "surgical" aneurysm) or failure of EVT (5%). Operatively, 48% of UIAs had thin wall or blebs and 71% were occluded with one titanium clip. Thrombectomy or temporary clipping were necessary in 4% and 11% of the cases, three aneurysms peroperatively ruptured, four were deemed unclippable, three paraclinoid UIAs had an intracavernous residue and 16% were wrapped because of a small neck remnant (class 2). The mortality rate was 0% and 4% of the patients experienced a definitive major neurological deterioration. Final GOS was unchanged in 96% of the patients.

CONCLUSIONS

Despite reduction in operative cases and in appropriately selected patients ineligible to EVT, microsurgical clipping of non-giant anterior circulation UIAs can still achieve good outcome with very low mortality and neurological morbidity.

[Very small intracranial aneurysms: Clip or coil]

INTRODUCTION

It is not unusual for very small aneurysms (≤3mm) to be responsible for subarachnoid haemorrhage. In addition, modern imaging has increased diagnosis of those that are asymptomatic. Because of their spatial configuration and thin and fragile walls, very small aneurysms can be a sizeable challenge for both open surgical and endovascular treatment. Based on recent literature data, the present manuscript reviews treatment indications and the choice of treatment strategy to occlude these particular aneurysms.

METHODS

Literature review concerning surgical and endovascular treatment of very small aneurysms (≤3mm). Arterial dissections and blister aneurysms were excluded.

RESULTS

We found no study that systematically and specifically assessed surgical treatment of very small aneurysms. Investigations of endovascular treatment are almost exclusively retrospective, usually evaluating a small number of patients, and are limited by selection bias. Despite often contradictory results, it appears that very small aneurysms carry a higher risk of rupture during endovascular procedures and higher ensuing mortality, as compared to larger aneurysms. The use of more flexible coils and additional endovascular tools appears to reduce this risk. There is no study comparing surgical to endovascular treatment.

CONCLUSION

Very small aneurysms carry higher treatment risks than larger aneurysms. A prospective randomised trial is justified for those very small aneurysms for which treatment is indicated.

RCTs in determining treatment indications for intracranial aneurysms: What can we learn from history?

BACKGROUND AND PURPOSE

Many important issues regarding the management of intracranial aneurysms remain controversial. We review the role played by randomized trials in the determination of the best management of intracranial aneurysms in the early era of surgical clipping.

METHODS

Landmark trials and cooperative studies are analyzed and results summarized in a narrative review.

RESULTS

The most convincing evidence in favour of surgical management of ruptured intracranial aneurysms came from early randomized trials conducted from the 1950s to 1970s. Large historical observational studies, performed between the 1970s and 2000, aiming to guide clinical practice, provided only statistical associations mixed with confounding variables. After the early RCTs, the next important gain in reliable knowledge occurred with completion of the ISAT trial, more than 25 years later.

CONCLUSION

The pioneering neurosurgeons of early trials can provide the inspiration necessary to make real progress in understanding the best clinical management of intracranial aneurysms.

The natural history and treatment options for unruptured intracranial aneurysms

Recent advances in angiographic technique have raised our awareness of the presence of unruptured intracranial aneurysms (UIAs). However, the appropriate management for these lesions remains controversial. To optimize patient outcomes, the physician must weigh aneurysmal rupture risk associated with observation against the complication risks associated with intervention. In the case that treatment is chosen, the two available options are surgical clipping and endovascular coiling. Our paper summarizes the current body of literature in regards to the natural history of UIAs, the evolution of the lesion if it progresses uninterrupted, as well as the safety and efficacy of both treatment options. The risks and benefits of treatment and conservative management need to be evaluated on an individual basis and are greatly effected by both patient-specific and aneurysm-specific factors, which are presented in this paper. Ultimately, this body of data has led to multiple sets of treatment guidelines, which we have summated and presented in this paper.

A trial on unruptured intracranial aneurysms (the TEAM trial): results, lessons from a failure and the necessity for clinical care trials

The trial on endovascular management of unruptured intracranial aneurysms (TEAM), a prospective randomized trial comparing coiling and conservative management, initiated in September 2006, was stopped in June 2009 because of poor recruitment (80 patients). Aspects of the trial design that may have contributed to this failure are reviewed in the hope of identifying better ways to successfully complete this special type of pragmatic trial which seeks to test two strategies that are in routine clinical use. Cultural, conceptual and bureaucratic hurdles and difficulties obstruct all trials. These obstacles are however particularly misplaced when the trial aims to identify what a good medical practice should be. A clean separation between research and practice, with diverging ethical and scientific requirements, has been enforced for decades, but it cannot work when care needs to be provided in the presence of pervasive uncertainty. Hence valid and robust scientific methods need to be legitimately re-integrated into clinical practice when reliable knowledge is in want. A special status should be reserved for what we would call 'clinical care trials', if we are to practice in a transparent and prospective fashion a medicine that leads to demonstrably better patient outcomes.