Mechanical embolectomy for acute ischemic stroke beyond six hours from symptom onset using MRI based perfusion imaging.
BACKGROUND
There is very limited data on the use of MRI based perfusion imaging to select patients with acute ischemic stroke and large vessel occlusion (LVO) for intraarterial therapy beyond 6h from onset. Our aim is to report the outcome of patients with acute ischemic stroke and large artery occlusion who presented beyond 6h from onset, had favorable MRI imaging profile, and underwent mechanical embolectomy.


METHODS
This is a single institution (Rhode Island Hospital) retrospective study between December 1st, 2015, and July 30th, 2016 that included patients with acute ischemic stroke and proximal LVO with CT ASPECTS of 6 or more and 6-24h from symptom onset who were assessed for mechanical embolectomy using MRI based perfusion imaging. Favorable imaging profile was defined based on prior studies as 1) DWI lesion volume (as defined as apparent diffusion coefficient<620×10-6mm2/s) of 70ml or less; 2) Penumbra volume (as defined by volume of tissue with Tmax>6s) of 15ml or greater; 3) A mismatch ratio of 1.8 or more; and 4) Volume of tissue with perfusion lesion with Tmax>10s is <100ml. Good outcome was defined as a 90-day mRS≤2.


RESULTS
41 patients met the inclusion criteria; 22 (53.7%) had favorable imaging profile and underwent mechanical embolectomy. The rate of good outcomes in this series was similar to that in a patient level pooled meta-analysis of the recent endovascular trials (63.6% vs. 46%, p=0.13). None of the patients in our cohort had symptomatic intracereberal hemorrhage.


CONCLUSIONS
MRI perfusion based imaging may help select patients with acute ischemic stroke and proximal emergent LVO for embolectomy beyond the treatment window used in most endovascular trials. This provides compelling evidence for stroke centers to participate in ongoing trials using advanced imaging to study endovascular treatment in this patient population.
Department of Diagnostic Imaging, The Warren Alpert Medical School of Brown University, Providence, RI, United States.
Ryan A
RA
McTaggart
Department of Neurology, The Warren Alpert Medical School of Brown University, Providence, RI, United States. Electronic address: syaghi@lifespan.org.
Shadi
S
Yaghi
Department of Neurology, The Warren Alpert Medical School of Brown University, Providence, RI, United States.
Daniel C
DC
Sacchetti
Department of Diagnostic Imaging, The Warren Alpert Medical School of Brown University, Providence, RI, United States.
Richard A
RA
Haas
Department of Neurology, The Warren Alpert Medical School of Brown University, Providence, RI, United States.
Morgan
M
Hemendinger
Department of Diagnostic Imaging, The Warren Alpert Medical School of Brown University, Providence, RI, United States.
Daniel
D
Arcuri
Department of Diagnostic Imaging, The Warren Alpert Medical School of Brown University, Providence, RI, United States.
Jeffrey M
JM
Rogg
Department of Neurology, The Warren Alpert Medical School of Brown University, Providence, RI, United States.
Karen L
KL
Furie
Department of Diagnostic Imaging, The Warren Alpert Medical School of Brown University, Providence, RI, United States; Department of Neurology, The Warren Alpert Medical School of Brown University, Providence, RI, United States; Department of Neurosurgery, The Warren Alpert Medical School of Brown University, Providence, RI, United States.
Mahesh V
MV
Jayaraman
D000368:Aged; D000369:Aged, 80 and over; D002545:Brain Ischemia / Q000150:complications; D002533:Cerebral Angiography; D017128:Embolectomy / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007091:Image Processing, Computer-Assisted; D018810:Magnetic Resonance Angiography; D008297:Male; D008875:Middle Aged; D012720:Severity of Illness Index; D020521:Stroke / Q000000981:diagnostic imaging* / Q000209:etiology / Q000601:surgery*; D016896:Treatment Outcome
Imaging; MRI; Outcome; Perfusion; Stroke; Thrombectomy; Treatment window