Outcomes of mechanical thrombectomy in M1 occlusion patients with or without hyperdense middle cerebral artery sign: A systematic review and meta-analysis

Background The comparison of mechanical thrombectomy (MT) outcomes between patients with the hyperdense middle cerebral artery sign (HMCAS) and non-HMCAS is important to evaluate the impact of this radiological finding on treatment efficacy. This meta-analysis aimed to assess the association between HMCAS and clinical outcomes in patients undergoing thrombectomy, comparing the outcomes over non-HMCAS. Methods A systematic literature search was conducted in PubMed, Ovid Embase, Google Scholar, and Cochrane Library to identify studies on MT outcomes for M1 occlusions of HMCAS over non-HMCAS. Inclusion criteria encompassed modified Rankin Scale (mRS) score, mortality, symptomatic intracranial hemorrhage (sICH), and successful recanalization. Using R software version 4.1.2, we calculated pooled odds ratios (ORs) and their corresponding 95% confidence intervals (CI). Results The meta-analysis was performed for 5 studies with 724 patients. There was no association found between presence of HMCAS and achieving mRS 0-2 (OR = 0.65, 95% CI: 0.29-1.47; p = .544). Mortality analysis also showed no significant association with presence of HMCAS (OR = 0.78, 95% CI: 0.37-1.65; p = .520). No significant difference in sICH risk (OR = 1.54, 95% CI: 0.24-9.66; p = .646) was found between groups. Recanalization analysis showed a non-significant positive association (OR = 1.23, 95% CI: 0.67-2.28; p = .501). Heterogeneity was observed in all analyses. Conclusion Our findings showed that there is no statistically significant difference in mRS scores, mortality, sICH, and recanalization success rates between the HMCAS and non-HMCAS groups.