Impact of reperfusion after 3 hours of symptom onset on tissue fate in acute cerebral ischemia.
BACKGROUND
Reperfusion of penumbral tissue is a promising strategy for treatment of acute cerebral ischemia more than 3 hours from symptom onset. However, there has been only sparse direct evidence that reperfusion after 3 hours prevents infarct growth.


METHODS
We analyzed clinical and serial magnetic resonance imaging (MRI) data on patients who received endovascular recanalization therapy 3-12 hours after last known well time. Multimodal MRIs were acquired pretreatment, early (1-20 hours), and late (2-7 days) after treatment. Degree of recanalization was assessed on end of procedure catheter angiogram, degree of reperfusion on early posttreatment perfusion MRI, and infarct growth by analysis of diffusion lesion volumes on pretreatment and late MRIs.


RESULTS
Twenty-seven (12 men, 15 women) underwent endovascular recanalization procedures at 6.0 +/- 2.1 hours (range, 3.0-11.5 hours) after last known well time. Immediate posttreatment perfusion lesion (Tmax > or =4 seconds) volume correlated strongly with infarct growth (r= .951, P < .001), exceeding the correlations of vessel recanalization score (r=-.198, P= .446) and pretreatment diffusion-perfusion mismatch volume (r= .518, P= .033). Without reperfusion, enlargement of DWI lesion volume was observed in all patients, and extent of enlargement depended on volume of immediate posttreatment perfusion defects.


CONCLUSIONS
Our data indicate that posttreatment reperfusion is the major determinant of threatened tissue outcome, and suggest reperfusion even after 3 hours of symptom onset can alter tissue fate over a wide range of mismatch volumes.
Bang
Oh Young
OY
Department of Neurology, University of California, Los Angeles, CA, USA.
Liebeskind
David S
DS
Buck
Brian H
BH
Yoon
Sa Rah
SR
Alger
Jeffry R
JR
Ovbiagele
Bruce
B
Saver
Jeffrey L
JL
D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001921:Brain / Q000098:blood supply* / Q000473:pathology* / Q000601:surgery; D002545:Brain Ischemia / Q000473:pathology* / Q000601:surgery / Q000628:therapy*; D002533:Cerebral Angiography; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D006801:Humans; D018810:Magnetic Resonance Angiography; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D015424:Reperfusion; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome; D055815:Young Adult