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.