Thrombectomy Outcomes of Intracranial Atherosclerosis-Related Occlusions: A Systematic Review and Meta-Analysis

Background and Purpose Intracranial atherosclerosis (ICAS) is an important cause of large vessel occlusion and poses unique challenges for emergent endovascular thrombectomy. The risk factor profile and therapeutic outcomes of patients with ICAS-related occlusions (ICAS-O) are unclear. We performed a systematic review and meta-analysis of studies reporting the clinical features and thrombectomy outcomes of large vessel occlusion stroke secondary to underlying ICAS (ICAS-O) versus those of other causes (non-ICAS-O). Methods A literature search on thrombectomy for ICAS-O was performed. Random-effect meta-analysis was used to analyze the prevalence of stroke risk factors and outcomes of thrombectomy between ICAS-O and non-ICAS-O groups. Results A total of 1967 patients (496 ICAS-O and 1471 non-ICAS-O) were included. The ICAS-O group had significantly higher prevalence of hypertension (odds ratio [OR] 1.46; 95% CI, 1.10-1.93), diabetes mellitus (OR, 1.68; 95% CI, 1.29-2.20), dyslipidemia (OR, 1.94; 95% CI, 1.04-3.62), smoking history (OR, 2.11; 95% CI, 1.40-3.17) but less atrial fibrillation (OR, 0.20; 95% CI, 0.13-0.31) than the non-ICAS-O group. About thrombectomy outcomes, ICAS-O had higher intraprocedural reocclusion rate (OR, 23.7; 95% CI, 6.96-80.7), need for rescue balloon angioplasty (OR, 9.49; 95% CI, 4.11-21.9), rescue intracranial stenting (OR, 14.9; 95% CI, 7.64-29.2), and longer puncture-to-reperfusion time (80.8 versus 55.5 minutes, mean difference 21.3; 95% CI, 11.3-31.3). There was no statistical difference in the rate of final recanalization (modified Thrombolysis in Cerebral Infarction score of 2b/3; OR, 0.67; 95% CI, 0.36-1.27), symptomatic intracerebral hemorrhage (OR, 0.79; 95% CI, 0.50-1.24), good functional outcome (modified Rankin Scale score of 0-2; OR, 1.16; 95% CI, 0.85-1.58), and mortality (OR, 0.94; 95% CI, 0.64-1.39) between ICAS-O and non-ICAS-O. Conclusions Patients with ICAS-O display a unique risk factor profile and technical challenges for endovascular reperfusion therapy. Intraprocedural reocclusion occurs in one-third of patients with ICAS-O. Intraarterial glycoprotein IIb/IIIa inhibitors infusion, balloon angioplasty, and intracranial stenting may be viable rescue treatment to achieve revascularization, resulting in comparable outcomes to non-ICAS-O.