title: A population-based incidence of acute large vessel occlusions and thrombectomy eligible patients indicates significant potential for growth of endovascular stroke therapy in the USA.
abstract: BACKGROUND
  Data on large vessel strokes are important for resource allocation and infrastructure development.
  
  
  OBJECTIVE
  To determine an annual incidence of large vessel occlusions (LVOs) and a thrombectomy eligible patient population.
  
  
  METHODS
  All patients with acute ischemic stroke discharged over 3 years from a tertiary-level hospital serving a large geographic area were evaluated for an LVO (M1, internal carotid artery terminus, basilar artery). The incidence of LVO was determined for the hospital's 4-county primary service area (PSA, population 210 000) based on each county's discharges and extrapolated to the US population. 'Thrombectomy eligibility' for anterior circulation LVOs was based on time (onset <6 hours) and imaging (Alberta Stroke Program Early CT Score (ASPECTS) ≥6). The number of annual thrombectomy procedures was calculated for Medicare and private payer patients using federally available databases.
  
  
  RESULTS
  1157 patients were discharged from the hospital's PSA, of whom 129 (11.1%, 95% CI 9.5% to 13.1%) had an LVO. This translated into an LVO incidence of 24 per 100 000 people per year (95% CI 20 to 28). 20 per 100 000 people per year had anterior circulation LVOs (95% CI 19 to 22), of whom 10/100 000/year (95% CI 8 to 11) were 'thrombectomy eligible'. An additional 5/100 000/year (95% CI 3 to 6) presented with favorable ASPECTS after 6 hours of symptom onset. Basilar occlusion incidence was estimated at 4/100 000/year (95% CI 2 to 5). These rates yield 77 569 (95% CI 65 835 to 91 091) new LVOs per year in the USA. An estimated 10 284 mechanical thrombectomy procedures were performed in 2015.
  
  
  CONCLUSIONS
  This study estimates an LVO incidence of 24 per 100 000 person-years (95% CI 20 to 28). A current estimated annual thrombectomy rate of three procedures per 100 000 people indicates significant potential increase in the volume of endovascular procedures and the need to develop systems of care.
authors.affiliation: Department of Interventional Neuroradiology, West Virginia University, Morgantown, West Virginia, USA.
authors.forename: Ansaar T
authors.initials: AT
authors.lastname: Rai
authors.affiliation: Department of Interventional Neuroradiology, West Virginia University, Morgantown, West Virginia, USA.
authors.forename: Aaron E
authors.initials: AE
authors.lastname: Seldon
authors.affiliation: Department of Interventional Neuroradiology, West Virginia University, Morgantown, West Virginia, USA.
authors.forename: SoHyun
authors.initials: S
authors.lastname: Boo
authors.affiliation: Stryker Neurovascular, Fremont, California, USA.
authors.forename: Paul S
authors.initials: PS
authors.lastname: Link
authors.affiliation: Department of Interventional Neuroradiology, West Virginia University, Morgantown, West Virginia, USA.
authors.forename: Jennifer R
authors.initials: JR
authors.lastname: Domico
authors.affiliation: Department of Neuroradiology, West Virginia University, Morgantown, West Virginia, USA.
authors.forename: Abdul R
authors.initials: AR
authors.lastname: Tarabishy
authors.affiliation: Department of Interventional Neuroradiology, West Virginia University, Morgantown, West Virginia, USA.
authors.forename: Noelle
authors.identifier: http://orcid.org/0000-0002-7961-3701
authors.initials: N
authors.lastname: Lucke-Wold
authors.affiliation: Department of Interventional Neuroradiology, West Virginia University, Morgantown, West Virginia, USA.
authors.forename: Jeffrey S
authors.initials: JS
authors.lastname: Carpenter
mesh_terms: D000368:Aged; D001488:Basilar Artery / Q000000981:diagnostic imaging / Q000601:surgery; D002545:Brain Ischemia / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000601:surgery*; D002343:Carotid Artery, Internal / Q000000981:diagnostic imaging / Q000601:surgery; D057510:Endovascular Procedures / Q000379:methods* / Q000639:trends; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011159:Population Surveillance / Q000379:methods; D020521:Stroke / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000601:surgery*; D017131:Thrombectomy / Q000379:methods* / Q000639:trends; D014481:United States / Q000453:epidemiology
keywords: Economics; Standards; Statistics; Stroke; Thrombectomy