Deep medullary vein drainage and unfavorable outcomes in stroke patients after endovascular therapy: a retrospective study

BACKGROUND: Ischemic stroke due to middle cerebral artery (MCA) or internal carotid artery (ICA) occlusion often involves deep white matter, which drains through deep medullary veins (DMVs). Whether disruption of the DMVs drainage contributes to unfavorable outcomes following endovascular thrombectomy (EVT) remains unknown. This study aimed to investigate the association between DMVs continuity and post-EVT prognosis. METHODS: In this retrospective observational study from two stroke centers, we included stroke patients due to MCA or ICA occlusion who underwent EVT with successful recanalization between January 2023 and December 2024. The modified Rankin Scale (mRS) was recorded at 90 days. DMVs continuity was assessed on susceptibility weighted imaging (SWI) after EVT. Clinical data were analyzed using multivariable logistic regression and receiver operating characteristic (ROC) curves. RESULTS: A total of 61 patients was included (mean age: 65.4 ± 12.2 years; 63.9% male). Thirty patients (49.2%) achieved unfavorable outcomes (mRS 2-6). Compared to the favorable group, ipsilateral DMVs discontinuity was more frequent in the unfavorable group (70.0% vs. 41.9%, P = 0.040). DMV discontinuity remained independently associated with unfavorable outcomes post-EVT after adjusting for confounders (aOR = 3.23, 95% CI: 1.12-9.30, P = 0.030). ROC curve analysis indicated that the combined model of DMVs continuity status, baseline NIHSS score, and arterial collateral status showed good predictive value for prognosis post-EVT (AUC = 0.81, sensitivity = 73.3%, specificity = 80.6%). CONCLUSIONS: Impaired DMVs drainage is associated with unfavorable outcomes after EVT in ischemic stroke patients with MCA or ICA occlusion.