Collateral flow as causative of good outcomes in endovascular stroke therapy.
BACKGROUND
Endovascular reperfusion techniques are a promising intervention for acute ischemic stroke (AIS). Prior studies have identified markers of initial injury (arrival NIH stroke scale (NIHSS) or infarct volume) as predictive of outcome after these procedures. We sought to define the role of collateral flow at the time of presentation in determining the extent of initial ischemic injury and its influence on final outcome.


METHODS
Demographic, clinical, laboratory, and radiographic data were prospectively collected on a consecutive cohort of patients who received endovascular therapy for acute cerebral ischemia at a single tertiary referral center from September 2004 to August 2010.


RESULTS
Higher collateral grade as assessed by the American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology (ASITN/SIR) grading scheme on angiography at the time of presentation was associated with improved reperfusion rates after endovascular intervention, decreased post-procedural hemorrhage, smaller infarcts on presentation and discharge, as well as improved neurological function on arrival to the hospital, discharge, and 90 days later. Patients matched by vessel occlusion, age, and time of onset demonstrated smaller strokes on presentation and better functional and radiographic outcome if found to have superior collateral flow. In multivariate analysis, lower collateral grade independently predicted higher NIHSS on arrival.


CONCLUSIONS
Improved collateral flow in patients with AIS undergoing endovascular therapy was associated with improved radiographic and clinical outcomes. Independent of age, vessel occlusion and time, in patients with comparable ischemic burdens, changes in collateral grade alone led to significant differences in initial stroke severity as well as ultimate clinical outcome.
Department of Neurology, University of California Los Angeles, Los Angeles, California, USA.
Sunil A
SA
Sheth
Keck School of Medicine of the University of Southern California, Los Angeles, California, USA.
Nerses
N
Sanossian
Department of Neurology, University of California Los Angeles, Los Angeles, California, USA.
Qing
Q
Hao
Department of Neurology, University of California Los Angeles, Los Angeles, California, USA Department of Emergency Medicine, University of California Los Angeles, Los Angeles, California, USA.
Sidney
S
Starkman
Department of Neurology, University of California Los Angeles, Los Angeles, California, USA.
Latisha K
LK
Ali
Department of Neurology, University of California Los Angeles, Los Angeles, California, USA.
Doojin
D
Kim
Division of Interventional Neuroradiology, University of California Los Angeles, Los Angeles, California, USA Department of Neurosurgery, University of California Los Angeles, Los Angeles, California, USA.
Nestor R
NR
Gonzalez
Division of Interventional Neuroradiology, University of California Los Angeles, Los Angeles, California, USA.
Satoshi
S
Tateshima
Division of Interventional Neuroradiology, University of California Los Angeles, Los Angeles, California, USA.
Reza
R
Jahan
Division of Interventional Neuroradiology, University of California Los Angeles, Los Angeles, California, USA.
Gary R
GR
Duckwiler
Department of Neurology, University of California Los Angeles, Los Angeles, California, USA.
Jeffrey L
JL
Saver
Division of Interventional Neuroradiology, University of California Los Angeles, Los Angeles, California, USA.
Fernando
F
Vinuela
Department of Neurology, University of California Los Angeles, Los Angeles, California, USA.
David S
DS
Liebeskind
D000368:Aged; D000369:Aged, 80 and over; D002545:Brain Ischemia / Q000175:diagnosis / Q000628:therapy*; D002560:Cerebrovascular Circulation / Q000502:physiology*; D003097:Collateral Circulation / Q000502:physiology*; D057510:Endovascular Procedures / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017063:Outcome Assessment, Health Care; D012720:Severity of Illness Index; D020521:Stroke / Q000175:diagnosis / Q000628:therapy*
Angiography; Blood Flow; MRI; Stroke; Thrombectomy