title: Collateral vessels in proximal middle cerebral artery occlusion: the ENDOSTROKE study.
abstract: OBJECTIVE
  To determine the impact of collateral vessel status on clinical and imaging outcomes in patients undergoing endovascular therapy (EVT) for proximal middle cerebral artery (MCA) occlusion.
  
  
  METHODS
  There were 160 patients with proximal MCA occlusion at six centers in this institutional review board-approved multicenter EVT registry. Angiograms were analyzed at a blinded core laboratory, and collateral vessel status was assessed by using the American Society of Interventional and Therapeutic Neuroradiology (ASITN)/Society of Interventional Radiology (SIR) collateral vessel grading system, while reperfusion was assessed by using the Thrombolysis in Cerebral Infarction (TICI) scale. Good outcome was defined as a modified Rankin Scale score of 0-2 at follow-up. Binary logistic regression analysis was performed by using parameters with P < .2 in univariate analysis.
  
  
  RESULTS
  Good clinical outcome was attained in 62 (39%) of the 160 patients, and TICI 2b-3 reperfusion was achieved in 94 (59%) patients. Nineteen patients had ASITN/SIR collateral vessel grades of 0 or 1, 63 patients had a grade of 2, and 78 patients had grades of 3 or 4. Better collateral vessels were associated with higher reperfusion rates (21%, 48%, and 77% for ASITN/SIR grades of 0 or 1, 2, and 3 or 4, respectively; P < .001), a higher proportion of infarcts smaller than one-third of the MCA territory (32%, 48%, and 69% for ASITN/SIR grades of 0 or 1, 2, and 3 or 4, respectively; P < .001), and a higher proportion of good clinical outcome (11%, 35%, and 49% for ASITN/SIR grades of 0 or 1, 2, and 3 or 4, respectively; P = .007). At multivariable analysis, collateral vessel status independently predicted reperfusion, final infarct size, and clinical outcome. Within an onset-to-treatment time (OTT) of 0-3 hours, collateral vessel status predicted final infarct size and reperfusion. Within an OTT of 3-6 hours, it additionally predicted clinical outcome, with 53% of patients with ASITN/SIR grades of 3 or 4 having a good outcome, as compared with 0% of patients with grades of 0 or 1 and 27% of patients with a grade of 2 (P = .008).
  
  
  CONCLUSIONS
  In this patient population, collateral vessel status independently predicted the pivotal outcome parameters of reperfusion, infarct size, and clinical outcome. These data underscore the utility of patient selection for EVT on the basis of collateral vessel status.
authors.affiliation: From the Department of Neurology (O.C.S.) and Institute for Neuroradiology (J.B.), Goethe University, Schleusenweg 2-16, D-60528 Frankfurt/Main, Germany; Department of Neurology (C.H.N.) and Institute for Diagnostic and Interventional Radiology and Nuclear Medicine (G.B.), Charité Hospital, Berlin, Germany; Department of Neurology (A.R.) and Institute for Diagnostic and Interventional Neuroradiology (M.W.), University Hospital Aachen, Aachen, Germany; Department of Neurology (K.G.) and Institute for Neuroradiology (S.B.), University Hospital Mainz, Mainz, Germany; Department of Neurology (T.N.) and Institute for Diagnostic and Interventional Neuroradiology (E.H.), Klinikum Fulda, Fulda, Germany; Department of Neurology (A.S.) and Institute for Radiology (A.B.), Klinikum Altenburger Land, Altenburg, Germany; and UCLA Stroke Center and Department of Neurology, University of California-Los Angeles, Los Angeles, Calif (D.S.L.).
authors.forename: Oliver C
authors.initials: OC
authors.lastname: Singer
authors.forename: Joachim
authors.initials: J
authors.lastname: Berkefeld
authors.forename: Christian H
authors.initials: CH
authors.lastname: Nolte
authors.forename: Georg
authors.initials: G
authors.lastname: Bohner
authors.forename: Arno
authors.initials: A
authors.lastname: Reich
authors.forename: Martin
authors.initials: M
authors.lastname: Wiesmann
authors.forename: Klaus
authors.initials: K
authors.lastname: Groeschel
authors.forename: Stephan
authors.initials: S
authors.lastname: Boor
authors.forename: Tobias
authors.initials: T
authors.lastname: Neumann-Haefelin
authors.forename: Erich
authors.initials: E
authors.lastname: Hofmann
authors.forename: Anett
authors.initials: A
authors.lastname: Stoll
authors.forename: Albrecht
authors.initials: A
authors.lastname: Bormann
authors.forename: David S
authors.initials: DS
authors.lastname: Liebeskind
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003097:Collateral Circulation; D057510:Endovascular Procedures; D006801:Humans; D020244:Infarction, Middle Cerebral Artery / Q000601:surgery*; D008875:Middle Aged; D012042:Registries; D012189:Retrospective Studies