Abstract Number ‐ 107: Better Late Than Never? ‐ Stroke Revascularization Beyond Day 10: Case Series And Literature Review
Authors: Nedelcu Simona , Kuhn Anna L , Qureshi Shakaib , Massari Francesco , Rex David E , Singh Jasmeet , Puri Ajit S , Silver Brian 
Published: April 2023

Introduction
In the last several years,there has been a paradigm shift in treating patients presenting with large vessel occlusion (LVO) strokes with endovascular therapy (EVT). Currently, the 24‐hour window has been incorporated in acute stroke management guidelines based on trials supporting the selection of patients with evidence of ischemic penumbra on perfusion imaging1,2. No current randomized control trials exist to support very late window EVT (beyond 24 hours) from last seen well (LSW) and its benefits are unknown. Several retrospective studies showed that EVT is safe and feasible up to 6 days from LSW in selected patients who are able preserve a favorable ischemic core to penumbra3, 4, 5. In this study we present a retrospective review of three patients with LVO strokes of the anterior circulation successfully treated between 10–14 days from LSW. We aim to explore the safety, efficiency and positive predictors of very late window EVT.

Methods
A single center retrospective review of stroke patients was performed. 517 patients with LVO strokes who underwent EVT between January 2018 and December 2021 were screened. 3 patients were found to have EVT performed 24 hours beyond LSW. Patient demographics, characteristics and clinical information were collected by systematic chart review. The primary outcome was functional independence as assessed by the modified Rankin Score (mRS) at 90 days. The safety outcomes included neurological deterioration and symptomatic intracranial hemorrhage, defined as an increase in National Institutes of Health Stroke Scale (NIHSS) of 4 or more). Further, a comprehensive literature review of studies describing very late window EVT cases indexed in PubMed was performed.

Results
We identifiedthree patients with LVO strokes, treated more than 24 hours from LSW. Patient ages ranged from 75 to 89 years. Baseline NIHSS ranged from 1 to 13. All patients had LVO or stenosis of the anterior circulation (internal carotid artery and/or M1 segment of the middle cerebral artery). All patients had fluctuation in their symptoms with worsening going from a supine position to a sitting position, evidence of ischemic penumbra on perfusion imaging and slow infarct growth on repeat brain imaging. The time from LSW to intervention ranged from 11 to 14 days. Recanalization score ranged from 2B‐3. No patients had intracranial hemorrhage or neurological decline. mRS scores were 2, 4, and 6 at 3 months. The patient who died had preservation of neurological function but died in the hospital due to heart failure.

Conclusions
We conclude that widening of the EVT time window presents new opportunities to treat a select population of LVO stroke patients. To our knowledge, there are no other reports of EVT in LVO patients beyond 10 days of LSW. Patients who have evidence of large ischemic penumbra, fluctuation of symptoms with change in position or blood pressure, good collateral circulation, and small infarct core that grows slowly on repeat imaging may be reasonable candidates for delayed EVT. More data are needed to inform clinical practice.