Abstract DP022: Gradation of Prolonged Venous Transit Highlights the Impact of Deep Venous Drainage Impairment in Successfully Reperfused Anterior Circulation Large Vessel Occlusion Stroke

Background: Prolonged venous transit (PVT), derived from CT perfusion (CTP) imaging, serves as a surrogate for venous outflow (VO) impairment and has been associated with worse outcomes in acute ischemic stroke due to large vessel occlusion (AIS-LVO). However, the differential impact of superficial versus deep venous drainage impairment on functional outcomes remains unclear. Methods: We retrospectively analyzed 128 AIS-LVO patients from a prospective registry who underwent successful mechanical thrombectomy modified treatment in cerebral infarction (mTICI) 2b/2c/3 with available baseline CTP and 90-day modified Rankin Scale (mRS) scores. PVT- was defined as the absence of Tmax ≥10 s in the posterior superior sagittal sinus (SSS) or torcula (no VO impairment). PVT1 was defined as the presence of Tmax ≥10 s in the posterior SSS only (superficial VO impairment), and PVT2 as the presence of Tmax ≥10 s at the torcula with or without posterior SSS involvement (deep VO impairment). Multivariable logistic regression assessed the association between PVT gradation and 90-day mRS score. Results: The proportion of patients achieving favorable outcomes (mRS≤2) declined stepwise across PVT gradation: 60.9% in PVT-, 42.1% in PVT1, and 22.7 % in PVT2. After adjusting for age, admission NIHSS score, hypertension, hemorrhagic transformation, intravenous thrombolysis, and mTICI score, PVT gradation remained independently associated with reduced odds of favorable outcome. This association was primarily driven by the PVT2 group, with an adjusted odds ratio of 0.230 (95% CI, 0.068–0.780) compared to PVT- group. Conclusion: PVT gradation based on Tmax ≥10 s timing in distinct venous territories provides prognostic insight into the differential contributions of superficial versus deep venous drainage dysfunction, supporting the use of PVT as a meaningful VO imaging biomarker. Deep VO impairment, as reflected by PVT2, is the primary driver of worse functional outcomes despite successful reperfusion in AIS-LVO, indicating its stronger negative prognostic impact compared to superficial VO impairment.