Relationship between periventricular white matter hyperintensity burden and poor collaterals in ischemic stroke treated with mechanical thrombectomy.

Background and aims: White matter hyperintensity (WMH) might influence leptomeningeal collateral recruitment. The objective of this study was to investigate whether cSVD and, in particular, WMH burden are associated with poor collateral circulation in acute ischemic stroke (AIS). Methods: This retrospective study included consecutive adult patients with AIS admitted to the Sapienza University of Rome teaching hospital in 2023 and treated with mechanical thrombectomy (MT). STRIVE criteria were followed to assess cSVD signs on MRI; Fazekas scale was used to grade WMH (periventricular, deep, total). Collateral status was evaluated by the adapted American Society of Interventional and Therapeutic Radiology/Society of Interventional Radiology (ASITN/SIR) score on pre-treatment CT Angiography dichotomized into good (3-4) versus poor (0-2). Results: Overall, 80 patients (51.2% females; mean[SD] age of 73.1[13.8] years) were eligible for analysis; 44 (55%) patients had poor collaterals, and 41 (51.2%) patients had any cSVD sign. Multivariate analysis did not show significant association between standard total cSVD burden score and collateral status. However, when the single components of the score were analysed, total moderate/severe WMH (OR 5.897, 95%CI 1.949- 17.840, p=0.002) and, particularly, any degree of periventricular WMH (OR 2.834, 95%CI 1.281-6.273, p=0.010) resulted independent predictors of collateral status after adjustment for the well-known risk factors for cSVD and baseline NIHSS. Conclusions: Our study showed that the burden of WMH and, especially, of periventricular WMH, more than other signs of cSVD, could have a significant role in predicting cerebral collateral recruitment potential in AIS patients treated with MT.