Effect of Intravenous Thrombolysis on Clot Survival during Mechanical Thrombectomy in Acute Large Vessel Occlusion Strokes

BACKGROUND: The benefit of intravenous thrombolysis (IVT) before mechanical thrombectomy (MT) in patients with large vessel occlusion (LVO) stroke is uncertain. Conventional metrics of final modified thrombolysis in cerebral ischemia (mTICI) score and 90-d modified Rankin Scale may be insensitive to IVT effects on procedural complexity and duration. OBJECTIVE: To study the effect of IVT prior to MT on clot survival. METHODS: We performed a single-center retrospective analysis of 257 acute stroke patients with LVO undergoing MT and analyzed the effect of IVT prior to MT using a novel, pass-by-pass clot survival methodology. RESULTS: The use of IVT was associated with a significantly lower number of passes to attain mTICI 2B or greater (P = .002) or mTICI 3 (P = .039) reperfusion. The number of patients who achieved mTICI 2B or greater after the first pass was significantly higher in the IVT group (P = .003). This increased rate of reperfusion persisted into subsequent passes. CONCLUSION: IVT prior to MT reduces the number of thrombectomy passes required to achieve mTICI 2B or mTICI 3 reperfusion. This information should be considered as the merits of IVT prior to MT are debated.