Noninvasive Angiographic Results of Clipped or Coiled Intracranial Aneurysms: An Inter- and Intraobserver Reliability Study

Reliability and applicability of angiographic outcome scales in WEB device-treated aneurysms: a systematic review

PURPOSE

Various angiographic assessment scales have been used to report the results of endovascular treatment with the WEB device. We aimed to review the use and reliability of these scales.

METHODS

We systematically reviewed studies reporting angiographic outcomes of WEB-treated aneurysms from January 2010 to May 2023. We identified the studies that reported the reliability of the various scales. Data from eligible studies were extracted and evaluated by two independent reviewers, with discrepancies resolved by a third reviewer.

FINDINGS

The review identified 138 studies that used 12 different occlusion scales. The non-specific Raymond-Roy occlusion classification (RROC) was most commonly used (94/138 (68%)), followed by the Bicêtre Occlusion Scale Score (BOSS; 21/138 (15%)) and the Web Occlusion Scale (WOS; 16/138 (12%)), both specifically adapted to the WEB. Six reliability studies were identified, which included 16-30 cases evaluated by few (2-7) raters. Studies were too heterogenous to proceed with a meta-analysis. Substantial agreement in reporting angiographic results was shown in one study using the WOS (K = 0.70; 0.64-0.75), and one using the BOSS (K = 0.82; 0.68-0.96), but only when categories were dichotomized as complete versus incomplete occlusion. Most classifications can be translated into the RROC, allowing comparisons with other devices and treatment modalities. The RROC reached substantial agreement, but only between 2 raters in a small 26-patient study (k = 0.69; 0.46-0.93).

CONCLUSION

More agreement studies are needed to validate the reliability of angiographic outcome scales that can be used to compare WEB with other endovascular or surgical treatments.

Endovascular Parent Vessel Occlusion Versus Flow Diversion in the Treatment of Large and Giant Aneurysms: A Randomized Comparison

OBJECTIVE

Parent vessel occlusion (PVO) is a time-honored treatment for unclippable or uncoilable intracranial aneurysms. Flow diversion (FD) is a recent endovascular alternative that can occlude the aneurysm and spare the parent blood vessel. Our aim was to compare outcomes of FD with endovascular PVO.

METHODS

This is a prespecified treatment subgroup analysis of the Flow diversion in Intracranial Aneurysms trial (FIAT). FIAT was an investigator-led parallel-group all-inclusive pragmatic randomized trial. For each patient, clinicians had to prespecify an alternative management option to FD before stratified randomization. We report all patients for whom PVO was selected as the best alternative treatment to FD. The primary outcome was a composite of core-lab determined angiographic occlusion or near-occlusion at 3-12 months combined with an independent clinical outcome (mRS<3). Primary analyses were intent-to-treat. There was no blinding.

RESULTS

There were 45 patients (16.2% of the 278 FIAT patients randomized between 2011 and 2020 in 3 centers): 22 were randomly allocated to FD and 23 to PVO. Aneurysms were mainly large or giant (mean 22 mm) anterior circulation (mainly carotid) aneurysms. A poor primary outcome was reached in 11/22 FD (50.0%) compared to 9/23 PVO patients (39.1%) (RR: 1.28, 95% CI [0.66-2.47]; P = 0.466). Morbidity (mRS >2) at 1 year occurred in 4/22 FD and 6/23 PVO patients. Angiographic results and serious adverse events were similar.

CONCLUSIONS

The comparison between PVO and FD was inconclusive. More randomized trials are needed to better determine the role of FD in large aneurysms eligible for PVO.

The use of low dose CT scouts for MR safety screening: A multi-reader evaluation

INTRODUCTION

Plain film radiographs are recommended to assist in MRI safety screening of patients with unknown medical histories, especially in an emergency setting where patients might be unable to answer a safety questionnaire. This study assesses the performance of CT scout images, which have low radiation dose and are faster and easier to acquire compared to plain film radiographs, in finding and naming a range of head and body implants.

METHODS

A retrospective analysis of 40 CT Head and Neck (HN) scout images and 40 CT Chest, Abdomen and Pelvis (CAP) scout images was undertaken. A subset of these were chosen to include a range of common internal implants not identifiable externally to the patient. The images were assessed by three readers with varying levels of clinical experience in MRI who were asked to find and name any implants seen.

RESULTS

Collectively, all readers reached a sensitivity of 85 % in finding internal implants, regardless of their clinical experience or experience in reviewing CT images, and a minimum specificity of 95 %. Implants were correctly named in 74 % of the images presented.

CONCLUSION

CT scout images were able to reveal most of the implants included. However, clinical experience in reviewing the images enhances a reader's ability to identify the type of implant.

IMPLICATIONS FOR PRACTICE

In an emergency setting, imaging can be critical in the management of patients presenting with acute illnesses. In the unconscious or unresponsive patient, the use of CT scouts, where this is the only option available, could provide valuable MRI safety information prior to a scan, improving access to the MRI scan in a timely manner.

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.

Stent-Assisted Coiling in the Treatment of Unruptured Intracranial Aneurysms: A Randomized Clinical Trial

BACKGROUND AND PURPOSE

Stent-assisted coiling may improve angiographic results of endovascular treatment of unruptured intracranial aneurysms compared with coiling alone, but this has never been shown in a randomized trial.

MATERIALS AND METHODS

The Stenting in the Treatment of Aneurysm Trial was an investigator-led, parallel, randomized (1:1) trial conducted in 4 university hospitals. Patients with intracranial aneurysms at risk of recurrence, defined as large aneurysms (≥10 mm), postcoiling recurrent aneurysms, or small aneurysms with a wide neck (≥4 mm), were randomly allocated to stent-assisted coiling or coiling alone. The composite primary efficacy outcome was "treatment failure," defined as initial failure to treat the aneurysm; aneurysm rupture or retreatment during follow-up; death or dependency (mRS > 2); or an angiographic residual aneurysm adjudicated by an independent core laboratory at 12 months. The primary hypothesis (revised for slow accrual) was that stent-assisted coiling would decrease treatment failures from 33% to 15%, requiring 200 patients. Primary analyses were intent to treat.

RESULTS

Of 205 patients recruited between 2011 and 2021, ninety-four were allocated to stent-assisted coiling and 111 to coiling alone. The primary outcome, ascertainable in 203 patients, was reached in 28/93 patients allocated to stent-assisted coiling (30.1%; 95% CI, 21.2%-40.6%) compared with 30/110 (27.3%; 95% CI, 19.4%-36.7%) allocated to coiling alone (relative risk = 1.10; 95% CI, 0.7-1.7; P  = .66). Poor clinical outcomes (mRS >2) occurred in 8/94 patients allocated to stent-assisted coiling (8.5%; 95% CI, 4.0%-16.6%) compared with 6/111 (5.4%; 95% CI, 2.2%-11.9%) allocated to coiling alone (relative risk = 1.6; 95% CI, 0.6%-4.4%; P  = .38).

CONCLUSIONS

The STAT trial did not show stent-assisted coiling to be superior to coiling alone for wide-neck, large, or recurrent unruptured aneurysms.

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.

Middle Cerebral Artery Aneurysm Trial (MCAAT): A randomized care trial comparing surgical and endovascular management of MCA aneurysm patients

BACKGROUND

Whether the best management of middle cerebral artery (MCA) aneurysm patients is surgical or endovascular remains uncertain, with little evidence to guide decision-making. A randomized care trial offering MCA aneurysm patients a 50% chance of surgical and a 50% chance of endovascular management may optimize outcomes in the presence of uncertainty.

METHODS

The Middle Cerebral Artery Aneurysm Trial (MCAAT) is an investigator-initiated, multi-center, parallel group, prospective, 1:1 randomized controlled clinical trial. All adult patients with MCA aneurysms, ruptured or unruptured, amenable to surgical and endovascular treatment can be included. The composite primary outcome is 'Treatment Success': i) occlusion or exclusion of the aneurysm using the allocated treatment modality; ii) no intracranial hemorrhage during follow-up; iii) no retreatment of the target aneurysm during follow-up, iv) no residual aneurysm on angiographic follow-up and v) independence (mRS <3) at 1 year. The trial tests two versions of the same hypothesis (one for ruptured and one for unruptured MCA aneurysm patients): Surgical management will lead to a 15% absolute increase in the proportion of patients reaching Treatment Success from 55% to 70% (ruptured) or from 75% to 90% (unruptured aneurysm patients) compared to endovascular treatment (any method). In this pragmatic trial, outcome evaluations are by treating physicians, except for 1 year angiographic results which will be core lab assessed. The trial will be monitored by an independent data safety monitoring committee to assure safety of participants. MCAAT is registered at clinicaltrials.gov: NCT05161377.

CONCLUSION

Patients with MCA aneurysms can be optimally managed within a care trial protocol.