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.

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.

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.

Reliability of the Diagnosis of Cerebral Vasospasm Using Catheter Cerebral Angiography: A Systematic Review and Inter- and Intraobserver Study.

BACKGROUND AND PURPOSE: Conventional angiography is the benchmark examination to diagnose cerebral vasospasm, but there is limited evidence regarding its reliability. Our goals were the following: 1) to systematically review the literature on the reliability of the diagnosis of cerebral vasospasm using conventional angiography, and 2) to perform an agreement study among clinicians who perform endovascular treatment. MATERIALS AND METHODS: Articles reporting a classification system on the degree of cerebral vasospasm on conventional angiography were systematically searched, and agreement studies were identified. We assembled a portfolio of 221 cases of patients with subarachnoid hemorrhage and asked 17 raters with different backgrounds (radiology, neurosurgery, or neurology) and experience (junior ≤10 and senior >10 years) to independently evaluate cerebral vasospasm in 7 vessel segments using a 3-point scale and to evaluate, for each case, whether findings would justify endovascular treatment. Nine raters took part in the intraobserver reliability study. RESULTS: The systematic review showed a very heterogeneous literature, with 140 studies using 60 different nomenclatures and 21 different thresholds to define cerebral vasospasm, and 5 interobserver studies reporting a wide range of reliability (κ = 0.14-0.87). In our study, only senior raters reached substantial agreement (κ ≥ 0.6) on vasospasm of the supraclinoid ICA, M1, and basilar segments and only when assessments were dichotomized (presence or absence of ≥50% narrowing). Agreement on whether to proceed with endovascular management of vasospasm was only fair (κ ≤ 0.4). CONCLUSIONS: Research on cerebral vasospasm would benefit from standardization of definitions and thresholds. Dichotomized decisions by experienced readers are required for the reliable angiographic diagnosis of cerebral vasospasm.

Does Increasing Packing Density Using Larger Caliber Coils Improve Angiographic Results of Embolization of Intracranial Aneurysms at 1 Year: A Randomized Trial.

BACKGROUND AND PURPOSE: The impact of increased aneurysm packing density on angiographic outcomes has not been studied in a randomized trial. We sought to determine the potential for larger caliber coils to achieve higher packing densities and to improve the angiographic results of embolization of intracranial aneurysms at 1 year. MATERIALS AND METHODS: Does Embolization with Larger Coils Lead to Better Treatment of Aneurysms (DELTA) was an investigator-initiated multicenter prospective, parallel, randomized, controlled clinical trial. Patients had 4- to 12-mm unruptured aneurysms. Treatment allocation to either 15- (experimental) or 10-caliber coils (control group) was randomized 1:1 using a Web-based platform. The primary efficacy outcome was a major recurrence or a residual aneurysm at follow-up angiography at 12 ± 2 months adjudicated by an independent core lab blinded to the treatment allocation. Secondary outcomes included indices of treatment success and standard safety outcomes. Recruitment of 564 patients was judged necessary to show a decrease in poor outcomes from 33% to 20% with 15-caliber coils. RESULTS: Funding was interrupted and the trial was stopped after 210 patients were recruited between November 2013 and June 2017. On an intent-to-treat analysis, the primary outcome was reached in 37 patients allocated to 15-caliber coils and 36 patients allocated to 10-caliber coils (OR = 0.931; 95% CI, 0.528-1.644; P = .885). Safety and other clinical outcomes were similar. The 15-caliber coil group had a higher mean packing density (37.0% versus 26.9%, P = .0001). Packing density had no effect on the primary outcome when adjusted for initial angiographic results (OR = 1.001; 95% CI, 0.981-1.022; P = .879). CONCLUSIONS: Coiling of aneurysms randomized to 15-caliber coils achieved higher packing densities compared with 10-caliber coils, but this had no impact on the angiographic outcomes at 1 year, which were primarily driven by aneurysm size and initial angiographic results.

A randomized trial of endovascular versus surgical management of ruptured intracranial aneurysms: Interim results from ISAT2.

BACKGROUND AND PURPOSE: Appropriate management of ruptured intracranial aneurysm (RIA) in patients eligible for surgical clipping but under-represented in or excluded from previous randomized trials remains undetermined. METHODS: The International Subarachnoid Aneurysm Trial-2 (ISAT-2) is a randomized care trial comparing surgical versus endovascular treatment (EVT) of RIA. All patients considered for surgical clipping but eligible for endovascular treatment can be included. The primary endpoint is death or dependency on modified Rankin score (mRS>2) at 1 year. Secondary endpoints are 1 year angiographic results and length of hospital stay. RESULTS: An interim analysis was performed after 103 patients were treated from November 2012 to July 2017 in 4 active centers. Fifty-two of the 55 patients allocated to surgery were treated by clipping, and 45 of the 48 allocated to EVT were treated by coiling, with 3 crossovers in each arm. The main endpoint (1 year mRS>2), available for 76 patients, was reached in 16/42 patients allocated to clipping (38%; 95%CI: 25%-53%), and 10/34 patients allocated to coiling (29%; 17%-46%). One year imaging results were available in 54 patients: complete aneurysm occlusion was found in 23/27 patients allocated to clipping (85%; 67%-94%), and 18/27 patients allocated to coiling (67%; 47%-81%). Hospital stay exceeding 20 days was more frequent in surgery (26/55 [47%; 34%-60%]) than EVT (9/48 [19%; 10%-31%]). CONCLUSION: Ruptured aneurysm patients for whom surgical clipping may still be best can be managed in a randomized care trial, which is feasible in some centers. More participating centers are needed.

Time for a Time Window Extension: Insights from Late Presenters in the ESCAPE Trial.

BACKGROUND AND PURPOSE: The safety and efficacy of endovascular therapy for large-artery stroke in the extended time window is not yet well-established. We performed a subgroup analysis on subjects enrolled within an extended time window in the Endovascular Treatment for Small Core and Proximal Occlusion Ischemic Stroke (ESCAPE) trial. MATERIALS AND METHODS: Fifty-nine of 315 subjects (33 in the intervention group and 26 in the control group) were randomized in the ESCAPE trial between 5.5 and 12 hours after last seen healthy (likely to have groin puncture administered 6 hours after that). Treatment effect sizes for all relevant outcomes (90-day mRS shift, mRS 0-2, mRS 0-1, and 24-hour NIHSS scores and intracerebral hemorrhage) were reported using unadjusted and adjusted analyses. RESULTS: There was no evidence of treatment heterogeneity between subjects in the early and late windows. Treatment effect favoring intervention was seen across all clinical outcomes in the extended time window (absolute risk difference of 19.3% for mRS 0-2 at 90 days). There were more asymptomatic intracerebral hemorrhage events within the intervention arm (48.5% versus 11.5%, P = .004) but no difference in symptomatic intracerebral hemorrhage. CONCLUSIONS: Patients with an extended time window could potentially benefit from endovascular treatment. Ongoing randomized controlled trials using imaging to identify late presenters with favorable brain physiology will help cement the paradigm of using time windows to select the population for acute imaging and imaging to select individual patients for therapy.

Enrichment of neuronal and glial connexins in the postsynaptic density subcellular fraction of rat brain.

The similar dense, protein-rich and detergent-resistant characteristics of postsynaptic densities (PSDs) and gap junctions led us to investigate the distribution of gap junctions and their constituent connexins in CNS subcellular fractions containing PSDs. Western blot analysis showed these fractions to be enriched in both neuronal and glial connexins, namely, connexin26, connexin30, connexin36 and connexin43. Connexins were retained in these fractions after treatment with n-lauroyl sarcosine to remove loosely associated proteins. Confocal double immunofluorescence confirmed the presence of connexins in PSD fractions and showed a near total co-localization of glial connexin30 and connexin43, demonstrating preservation of inter-connexin relationships that have been observed in vivo. In contrast, none of the connexins were co-localized with the PSD structural protein PSD-95, indicating their lack of direct association with PSDs. These results show that PSD preparations contain significant levels of connexin proteins, which appear to remain assembled as gap junctions. Thus, protocols used to isolate PSDs may serve as a basis for development of methods to isolate CNS gap junctions, which would aid biochemical identification of regulatory and structural proteins associated with these structures.