The predictors and prognosis for unexpected reocclusion after mechanical thrombectomy: a meta-analysis

Mechanical thrombectomy (MT) is the cornerstone for treating acute ischemic stroke (AIS) in emergency cases. However, 3-9% of patients display reocclusion in the recanalized vessels within 24 hours after performing MT. This meta-analysis aimed to further identify the predictors and prognosis of unexpected reocclusion after MT.

According to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement, we searched several literature databases, including PubMed, Embase, and Cochrane, for publications related to the subject term "thrombectomy" that were published prior to March 2020. Pooled analysis was performed with the fixed-effects model using the Mantel-Haenszel method if the heterogeneity was expected to be available (I²≤50%). Otherwise, the random-effects model computed by the DerSimonian-Laird method was used (I²>50%). R software (http://www.r-project.org) was used for analysis in this study.

A total of five articles comprising 1,883 patients (126 patients with reocclusion, 1,757 patients without reocclusion) who were confirmed to have AIS and who underwent emergency MT were finally included in this study. The pooled analysis (reocclusion versus non-reocclusion) showed that atrial fibrillation [odds ratio (OR), 0.36; 95% confidence interval (CI), 0.20-0.63], cardiogenic embolism (OR, 0.35; 95% CI, 0.20-0.63), long-term statin use (OR, 0.39; 95% CI, 0.21-0.75), long-term antiplatelet use (OR, 0.53; 95% CI, 0.31-0.92), and target occlusion at middle cerebral artery-M1 (MCA-M1) (OR, 0.39; 95% CI, 0.19-0.77) might prevent reocclusion and longer onset-to-reperfusion time (mean difference, 66.51; 95% CI, 36.66-96.35) might promote reocclusion after MT performance. Furthermore, the clinical outcomes including early neurological deterioration (OR, 4.87; 95% CI, 2.08-11.40), 90-day modified Rankin Scale score ≤2 (OR, 0.28; 95% CI, 0.18-0.45), and 90-day death rate (OR, 1.85; 95% CI, 1.04-3.29) were also associated with reocclusion after MT performance.

Atrial fibrillation, cardiogenic embolism, long-term statin use, long-term antiplatelet use, and target occlusion at MCA-M1 might prevent reocclusion, and longer onset-to-reperfusion time seemed to promote reocclusion after MT. Reocclusion after MT results in a high risk of poor prognosis.