Outcomes of Endovascular Treatment in Large Vessel Occlusions Due to Intracranial Atherosclerotic Disease: A Systematic Review and Updated Meta-Analysis of 11,326 Patients

BACKGROUND: Intracranial atherosclerotic disease (ICAD) is a major cause of large vessel occlusion (LVO) stroke and presents unique challenges for endovascular treatment (EVT). PURPOSE: To compare angiographic and clinical outcomes after EVT in patients with ICAD-related versus non-ICAD LVO. DATA SOURCES: PubMed, Embase, Web of Science, and Cochrane Central Register of Controlled Trials were searched from inception through July 2025. STUDY SELECTION: Studies enrolling adults with LVO undergoing EVT that directly compared ICAD and non-ICAD etiologies were included. DATA ANALYSIS: Random-effects models were used to pool odds ratios (OR). Risk of bias was assessed with ROBINS-I, and certainty of evidence (CoE) was evaluated using GRADE. DATA SYNTHESIS: Eighteen studies (3 prospective and 15 retrospective) comprising 11,326 patients (1,571 ICAD; 9,755 non-ICAD) were included. Mean age across cohorts was 72.8 years, and hypertension was the most common comorbidity. ICAD was associated with lower odds of successful reperfusion (OR, 0.46; 95%CI, 0.31-0.70; p<0.001; very-low CoE) and lower risk of sICH (OR, 0.72; 95%CI, 0.54-0.96; p=0.025; low CoE). No significant differences were observed for functional independence (OR, 0.90; 95%CI, 0.67-1.22; p=0.51; very-low CoE), favorable functional outcome (OR, 0.80; 95%CI, 0.43-1.51; p=0.45; very-low CoE), or mortality (OR, 1.16; 95%CI, 0.77-1.75; p=0.48; very-low CoE). LIMITATIONS: Included studies were observational, most were retrospective, and pooled estimates were derived from unadjusted comparisons. CONCLUSIONS: In pooled unadjusted comparisons, ICAD was associated with lower reperfusion success but similar functional and mortality outcomes compared to non-ICAD LVO, alongside a lower risk of symptomatic hemorrhage. These findings highlight the distinct pathophysiology of ICAD-LVO and the need for tailored EVT strategies and randomized trials for this population.