2026 Volume 20 Issue 1 Article ID: oa.2025-0119
Objective: Intracranial arterial calcification (ICAC) has been suggested to influence the outcomes of mechanical thrombectomy (MT) for acute ischemic stroke. We conducted a systematic review and meta-analysis to evaluate MT outcomes in patients with acute ischemic stroke and large-vessel occlusions involving intracranial calcified arteries.
Methods: This study followed the Cochrane and Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. Peer-reviewed studies were included if they evaluated intracranial arterial calcification (≥130 Hounsfield unit [HU] on noncontrast computed tomography) in patients undergoing MT within 24 h of acute ischemic stroke and reported modified Rankin Scale (mRS) score at 90 days or the final thrombolysis in cerebral infarction (TICI) grade. Four databases (PubMed, Cochrane Library, Web of Science, and Embase) were searched from inception to July 2025. Two reviewers independently screened and extracted the data and assessed their quality using the Newcastle–Ottawa Scale. Odds ratios (OR) were pooled using Mantel–Haenszel random-effects models, and heterogeneity was assessed using I2.
Results: Among 968 records, 4 observational studies (n = 832; 2016–2024) met the inclusion criteria. All were adjusted for baseline factors using multivariable or propensity score models. The quality of the studies ranged from moderate to high. The ICAC definitions varied as follows: morphological (intimal vs. medial), location-based (symptomatic vs. asymptomatic), or volumetric assessments. Meta-analysis showed that ICAC—particularly in studies distinguishing intimal from medial calcification—was significantly associated with poor 90-day outcomes (mRS 3–6) (pooled OR 1.74; 95% CI 1.21–2.52; p <0.001; I2 = 49%). In a subanalysis focusing on calcification volume, increased volume alone was not consistently associated with worse functional outcomes or lower reperfusion success (pooled OR ≈ 1.19; 95% CI 0.78–1.80). Collectively, the lack of association in the volume-based analysis and the significant association observed in studies incorporating intimal–medial differentiation suggest that lesion morphology—particularly the presence of intimal calcification—may exert a greater influence on MT outcomes than calcification volume itself.
Conclusion: ICAC, especially when intimal calcification is present, is independently associated with procedural complexity and poor functional outcomes after thrombectomy for acute ischemic stroke. The divergent findings between the volume subanalysis and the broader morphology-based analysis highlight that morphology-driven, rather than volume-driven, calcification better explains outcome variability. Recognition of ICAC on baseline imaging may aid in prognostication, guide device strategies, and anticipate adjunctive interventions. Standardized assessments and prospective validation studies are needed to optimize outcomes.
