Background and purpose: Several collateral scores have been published for stroke in the middle cerebral artery territory, each considering different aspects of cerebral collateralization. Currently, there is no gold standard in CT-based collateral assessment. The aim of this retrospective study was to compare five collateral scores and determine whether they are able to predict clinical outcome after thrombectomy as standalone parameters.
Methods: Inclusion criteria were M1 occlusion, premorbid modified Rankin scale (mRS) of 0-3, treatment with endovascular thrombectomy and groin puncture within 12 h after stroke onset. The Maas et al., Miteff et al., Tan et al., ASITN/SIR and mCTA collateral scores were retrospectively assessed in multiphase CTA images and correlated with 90-day mRS (90d-mRS) scores. Good outcome was defined as 90d-mRS 0-2 or unchanged to premorbid mRS.
Results: In total, 108 patients were included of which 39.8% achieved a good outcome. The area under the curve (AUC) values of receiver operating characteristic (ROC) curve analysis for Maas et al., Miteff et al., Tan et al., ASITN/SIR and mCTA scores were 0.60 (0.51-0.70), 0.60 (0.52-0.68), 0.61 (0.51-0.70), 0.59 (0.49-0.70) and 0.61 (0.50-0.71), respectively. The correlation between 90d-mRS and Maas (r = -0.16, P = 0.091), Miteff (r = -0.25, P = 0.009), Tan (r = -0.26, P = 0.007), ASITN/SIR (r = -0.21, P = 0.030) and mCTA (r = -0.22, P = 0.021) scores was poor.
Conclusion: Although collaterals are known to correlate with clinical outcome, none of the analyzed collateral scores sufficiently predicted outcome as a standalone parameter.
Keywords: ASITN/SIR; Maas; Miteff; Tan; mCTA.