Intracranial aneurysms represent a major global health burden. Rupture of an intracranial aneurysm is a catastrophic event. Without access to treatment, the fatality rate is 50% in the first 30 days. Over the last three decades, treatment approaches for intracranial aneurysms have changed dramatically. There have been improvements in the medical management of aneurysmal subarachnoid haemorrhage, and there has been an evolution of treatment strategies. Endovascular therapy is now the mainstay of the treatment of ruptured intracranial aneurysms based on robust randomised controlled trial data. There is now an expansion of treatment indications for unruptured intracranial aneurysms to prevent rupture with both microsurgical clipping and endovascular treatment. Both microsurgical and endovascular treatment modalities have evolved, in particular with the introduction of innovative endovascular treatment options including flow diversion and intra-saccular flow disruption. These novel therapies allow clinicians to treat more complex and previously untreatable aneurysms. We aim to review the evolution of treatment strategies for intracranial aneurysms over time, and discuss emerging technologies that could further improve treatment safety and functional outcomes for patients with an intracranial aneurysm.

BACKGROUND: Stroke secondary to intracranial atherosclerotic disease (ICAD) is associated with high recurrence risk despite currently available secondary prevention strategies. In patients with systemic atherosclerosis, a significant reduction of stroke risk with no increase in intracranial or fatal hemorrhage was seen when rivaroxaban 2.5 mg twice daily was added to aspirin. However, there are no trials in ICAD using this combination. To facilitate the design of future ICAD trials, the CATIS-ICAD study (Combination Antithrombotic Treatment for Prevention of Recurrent Ischemic Stroke in Intracranial Atherosclerotic Disease) assessed (1) the feasibility of recruitment, (2) the safety of low-dose rivaroxaban plus aspirin compared with standard-of-care antiplatelet therapy, and (3) trends toward efficacy. METHODS: This was a prospective, randomized, open-label, blinded end point pilot trial conducted in 10 Canadian centers. Eligible participants aged ≥40 years, with acute ischemic stroke or high-risk transient ischemic attack, were randomly assigned in a 1:1 ratio to receive low-dose rivaroxaban plus aspirin or aspirin alone within 7 to 100 days of their index event. The primary safety outcome was hemorrhagic stroke. The main efficacy end point was the composite of ischemic stroke or covert brain infarct on magnetic resonance imaging at the end of the study. RESULTS: A total of 101 participants were randomized. Average enrollment was 10 participants/site per year. Average follow-up was 20 months. Median time from index stroke to randomization was 67 days. The median age of participants was 67 years (±10.94), and 29% of participants were women. There was no hemorrhagic stroke in either arm. The composite efficacy outcome was less frequent in the combination arm (15.7%) compared with the aspirin arm (24.0%), with a hazard ratio of 0.78 ([95% CI, 0.32–1.93]; P =0.59) favoring the intervention. CONCLUSIONS: A multicenter randomized trial comparing the combination of low-dose rivaroxaban and aspirin in patients with recent ischemic stroke or transient ischemic attack due to ICAD is feasible and appears safe without an increased risk of hemorrhagic stroke. A numerical trend toward efficacy for the composite primary end point of symptomatic ischemic stroke and covert infarcts was observed. These findings will inform the design of a phase III trial. REGISTRATION: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT04142125.

BACKGROUND: Interhospital transfer for patients with stroke due to large vessel occlusion for endovascular thrombectomy (EVT) has been associated with treatment delays. METHODS: We analyzed data from Optimizing Patient Treatment in Major Ischemic Stroke With EVT, a quality improvement registry to support EVT implementation in Canada. We assessed for unadjusted differences in baseline characteristics, time metrics, and procedural outcomes between patients with large vessel occlusion transferred for EVT and those directly admitted to an EVT-capable center. RESULTS: Between January 1, 2018, and December 31, 2021, a total of 6803 patients received EVT at 20 participating centers (median age, 73 years; 50% women; and 50% treated with intravenous thrombolysis). Patients transferred for EVT (n=3376) had lower rates of M2 occlusion (22% versus 27%) and higher rates of basilar occlusion (9% versus 5%) compared with those patients presenting directly at an EVT-capable center (n=3373). Door-to-needle times were shorter in patients receiving intravenous thrombolysis before transfer compared with those presenting directly to an EVT center (32 versus 36 minutes). Patients transferred for EVT had shorter door-to-arterial access times (37 versus 87 minutes) but longer last seen normal-to-arterial access times (322 versus 181 minutes) compared with those presenting directly to an EVT-capable center. No differences in arterial access-to-reperfusion times, successful reperfusion rates (85% versus 86%), or adverse periprocedural events were found between the 2 groups. Patients transferred to EVT centers had a similar likelihood for good functional outcome (modified Rankin Scale score, 0–2; 41% versus 43%; risk ratio, 0.95 [95% CI, 0.88–1.01]; adjusted risk ratio, 0.98 [95% CI, 0.91–1.05]) and a higher risk for all-cause mortality at 90 days (29% versus 25%; risk ratio, 1.15 [95% CI, 1.05–1.27]; adjusted risk ratio, 1.14 [95% CI, 1.03–1.28]) compared with patients presenting directly to an EVT center. CONCLUSIONS: Patients transferred for EVT experience significant delays from the time they were last seen normal to the initiation of EVT.

BACKGROUND: Following an acute ischemic stroke, the risk of recurrent stroke is highest in the first 90 days. It is unclear whether this risk is altered by reperfusion therapy. In this meta-analysis, we aim to evaluate the risk of early recurrent stroke and other nonstroke thrombotic events postreperfusion therapy in acute ischemic stroke. METHODS: In this meta-analysis, randomized controlled trials (RCTs) were included in adults aged 18 years or older with acute ischemic stroke, comparing reperfusion treatment with best medical management (MED). We searched PUBMED, Embase, Cochrane Library, and Web of Science databases. The studies were grouped into endovascular thrombectomy (EVT) versus MED and intravenous thrombolysis versus MED. We performed a meta-analysis using a random-effects model (restricted maximum likelihood) to estimate the log risk ratio (RR) of early recurrent stroke and nonstroke thrombotic events (NSTE)—including myocardial infarction, acute coronary syndrome, deep vein thrombosis, pulmonary embolism, and peripheral embolism—after reperfusion therapy compared with MED at 90 days after symptom onset. This study is registered with PROSPERO (The International Prospective Register of Systematic Reviews). RESULTS: A total of 15 RCTs (n=4898) comparing EVT versus MED observed no difference in early recurrent stroke (5.5%, 143/2618 versus 4.5%, 102/2280; RR, 1.2 [95% CI, 0.9–1.6]). Nine RCTs (n=7193) comparing intravenous thrombolysis versus MED observed no difference in early recurrent stroke (2%, 73/3615 versus 1.8%, 66/3578; RR, 1.1 [95% CI, 0.8–1.5]). Fourteen RCTs (n=4033) comparing EVT versus MED reported NSTE. There was no difference in NSTE in the EVT arm (3.1%, 62/2024 versus 3.1%, 62/2009; RR, 1 [95% CI, 0.7–1.4]). Five RCTs (n=4961) comparing intravenous thrombolysis versus MED observed no difference in NSTE (2%, 51/2479 versus 2.2%, 54/2482; RR, 0.9 [95% CI, 0.6–1.4]). CONCLUSIONS: Reperfusion therapies (EVT±intravenous thrombolysis) in acute ischemic stroke within 24 hours of symptom onset were not associated with increased recurrent stroke or NSTE within 90 days compared with best medical therapy. REGISTRATION: URL: https://www.crd.york.ac.uk/PROSPERO/ ; Unique identifier: CRD42024542020.