Repeated Intravenous Thrombolysis for Ischemic Stroke With Medium to Large Vessel Occlusion Presenting Within 4.5 Hours of Onset With Prourokinase

Ischemic cerebrovascular disease is a common neurological disorder with high incidence, mortality, and disability. Early reperfusion to salvage the ischemic penumbra is the cornerstone of acute ischemic stroke (AIS) treatment. Current reperfusion strategies include intravenous thrombolysis (IVT) and endovascular therapy (EVT). Although alteplase is the first-line thrombolytic agent, its recanalization rate for large vessel occlusion (LVO) is only 10-20%, and for medium vessel occlusion (MeVO), approximately 50% of patients fail to achieve recanalization, leading to poor outcomes. Prourokinase has recently been shown to be non-inferior to alteplase with a better safety profile, and studies suggest that repeated thrombolysis may improve recanalization rates in patients without early clinical improvement after standard IVT. Therefore, this study aims to evaluate the efficacy and safety of an additional intravenous infusion of prourokinase in AIS patients with confirmed medium or large vessel occlusion who show no significant clinical improvement at 1 hour after standard IVT (within 4.5 hours of symptom onset). Patients without early neurological improvement (e.g., \<2-point reduction in NIHSS) and persistent vessel occlusion on imaging will receive a second dose of prourokinase. The primary outcomes include 24-hour recanalization rate (by CTA/MRA), 90-day functional outcome (modified Rankin Scale), and safety endpoints (symptomatic intracranial hemorrhage, mortality). The hypothesis is that additional prourokinase following standard IVT in non-improving patients with medium or large vessel occlusion will significantly increase recanalization rates and improve clinical outcomes without an unacceptable increase in symptomatic intracranial hemorrhage.