BACKGROUND AND PURPOSE: Intracranial collaterals influence the prognosis of patients treated with intravenous tissue plasminogen activator in acute anterior circulation ischemic stroke. We compared the methods of scoring collaterals on pre-tPA brain CT angiography for predicting functional outcomes in acute anterior circulation ischemic stroke. MATERIALS AND METHODS: Two hundred consecutive patients with acute anterior circulation ischemic stroke treated with IV-tPA during 2010–2012 were included. Two independent neuroradiologists evaluated intracranial collaterals by using the Miteff system, Maas system, the modified Tan scale, and the Alberta Stroke Program Early CT Score 20-point methodology. Good and extremely poor outcomes at 3 months were defined by modified Rankin Scale scores of 0–1 and 5–6 points, respectively. RESULTS: Factors associated with good outcome on univariable analysis were younger age, female sex, hypertension, diabetes mellitus, atrial fibrillation, small infarct core (ASPECTS ≥8), vessel recanalization, lower pre-tPA NIHSS scores, and good collaterals according to Tan methodology, ASPECTS methodology, and Miteff methodology. On multivariable logistic regression, only lower NIHSS scores (OR, 1.186 per point; 95% CI, 1.079–1.302; P = .001), recanalization (OR, 5.599; 95% CI, 1.560–20.010; P = .008), and good collaterals by the Miteff method (OR, 3.341; 95% CI, 1.203–5.099; P = .014) were independent predictors of good outcome. Poor collaterals by the Miteff system (OR, 2.592; 95% CI, 1.113–6.038; P = .027), Maas system (OR, 2.580; 95% CI, 1.075–6.187; P = .034), and ASPECTS method ≤5 points (OR, 2.685; 95% CI, 1.156–6.237; P = .022) were independent predictors of extremely poor outcomes. CONCLUSIONS: Only the Miteff scoring system for intracranial collaterals is reliable for predicting favorable outcome in thrombolyzed acute anterior circulation ischemic stroke. However, poor outcomes can be predicted by most of the existing methods of scoring intracranial collaterals.

Intravenous (IV) tissue plasminogen activator (tPA) remains the only approved therapeutic agent for arterial recanalization in acute ischemic stroke (AIS).¹ Although recanalization of the acutely occluded intracranial artery remains the major aim of IV tPA therapy in patients with AIS, to our knowledge, the relationship between arterial recanalization and stroke recovery has been described in only a few studies.^1,2 Recent studies that have reported recanalization mostly pertain to interventional therapies or a combined IV tPA and interventional approach rather than IV tPA only.^2-4 The information about early recanalization (ER) during the first 2 hours of IV tPA infusion may help physicians identify patients suitable for rescue reperfusion therapies. Some patients with ER may develop reocclusion within the first 24 hours and contribute to wide variations in the rates of favorable outcomes.^5,6 Identifying patients with reocclusion or persistent arterial occlusion (PAO) may help the treating physicians plan the optimal rehabilitative strategies and early prognostication. We evaluated the relationship between arterial patency and the timing of recanalization with functional outcomes at 3 months in patients with AIS treated with IV tPA.

Background: Mechanical thrombectomy (MT) has revolutionized the treatment of acute ischemic stroke (AIS) due to large vessel occlusion (LVO), but its efficacy and safety in medium vessel occlusion (MeVO) remain less explored. This multicenter, retrospective study aims to investigate the incidence and clinical outcomes of vessel perforations (confirmed by extravasation during an angiographic series) during MT for AIS caused by MeVO. Methods: Data were collected from 37 academic centers across North America, Asia, and Europe between September 2017 and July 2021. A total of 1373 AIS patients with MeVO underwent MT. Baseline characteristics, procedural details, and clinical outcomes were analyzed. Results: The incidence of vessel perforation was 4.8% (66/1373). Notably, our analysis indicates variations in perforation rates across different arterial segments: 8.9% in M3 segments, 4.3% in M2 segments, and 8.3% in A2 segments (p = 0.612). Patients with perforation had significantly worse outcomes, with lower rates of favorable angiographic outcomes (TICI 2c-3: 23% vs 58.9%, p < 0.001; TICI 2b-3: 56.5% vs 88.3%, p < 0.001). Functional outcomes were also worse in the perforation group (mRS 0–1 at 3 months: 22.7% vs 36.6%, p = 0.031; mRS 0–2 at 3 months: 28.8% vs 53.9%, p < 0.001). Mortality was higher in the perforation group (30.3% vs 16.8%, p = 0.008). Conclusion: This study reveals that while the occurrence of vessel perforation in MT for AIS due to MeVO is relatively rare, it is associated with poor functional outcomes and higher mortality. The findings highlight the need for increased caution and specialized training in performing MT for MeVO. Further prospective research is required for risk mitigation strategies.