CTP-Based Tissue Outcome: Promising Tool to Prove the Beneficial Effect of Mechanical Recanalization in Acute Ischemic Stroke.
OBJECTIVE
To prove the tissue-protecting effect of mechanical recanalization, we assessed the CT perfusion-based tissue outcome ("TO") and correlated this imaging parameter with the 3-month clinical outcome ("CO").


METHODS
159 patients with large intracranial artery occlusions revealing mechanical recanalization were investigated by CCT, CT angiography (CTA) and CT perfusion (CTP) upon admission. For the final infarct volume, native CCT was repeated after 24 h. The "TO" ("percentage mismatch loss" = %ML) was defined as the difference between initial penumbral tissue on CTP and final infarct volume on follow-up CCT. We monitored the three-month modified Rankin Scale (mRS), age, bleeding occurrence, time to recanalization, TICI score and collateralization grade, infarct growth and final infarct volume. Spearman's correlation and nominal regression analysis were used to evaluate the impact of these parameters on mRS.


RESULTS
Significant correlations were found for %ML and mRS (c = 0.48, p < 0.001), for final infarct volume and mRS (c = 0.52, p < 0.001), for TICI score and mRS (c = - 0.35, p < 0.001), for initial infarct core and mRS (c = 0.14, p = 0.039) as well as for age and mRS (c = 0.37, p < 0.001). According to the regression analysis, %ML predicted the classification of mRS correctly in 38.5 % of cases. The subclasses mRS 1 and 6 could be predicted by %ML with 86.4 % and 60.9 % reliability, respectively. No correlations were found for time to recanalization and mRS, for collateralization grade and mRS, and for post-interventional bleeding and mRS.


CONCLUSIONS
Better than the TICI score, CT-based TO predicts the clinical success of mechanical recanalization, showing that not recanalization, but reperfusion should be regarded as a surrogate parameter for stroke therapy.


CONCLUSIONS
• %ML as well as the final infarct volume can make a direct point about the immediate effect of successful mechanical recanalization.• The clinical outcomes after mechanical recanalization are reliably predicted by %ML, reflecting the benefit of escalation therapy including interventional reopening of parent vessel occlusions.• Not recanalization but rather reperfusion should be regarded as a surrogate parameter for successful stroke therapy.
Institute for Clinical Radiology, University Hospital Muenster, Germany.
F
F
Drewer-Gutland
Department of Neuroradiology, University Hospital Schleswig-Holstein, Lübeck, Germany.
A
A
Kemmling
Institute of Biostatistics and Clinical Research, University of Muenster, Germany.
S
S
Ligges
Department of Neurology, University Hospital Muenster, Germany.
M
M
Ritter
Department of Neurology, University Hospital Muenster, Germany.
R
R
Dziewas
Department of Neurology, University Hospital Muenster, Germany.
E B
EB
Ringelstein
Institute for Clinical Radiology, University Hospital Muenster, Germany.
T U
TU
Niederstadt
Institute for Clinical Radiology, University Hospital Muenster, Germany.
W
W
Heindel
Radiology/Neuroradiology, Asklepios-Clinic North, Hamburg, Germany.
V
V
Heßelmann
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002545:Brain Ischemia / Q000150:complications / Q000000981:diagnostic imaging* / Q000601:surgery*; D002533:Cerebral Angiography / Q000379:methods; D002548:Cerebral Revascularization / Q000295:instrumentation* / Q000379:methods; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D020521:Stroke / Q000150:complications / Q000000981:diagnostic imaging* / Q000601:surgery*; D014057:Tomography, X-Ray Computed / Q000379:methods; D016896:Treatment Outcome; D055815:Young Adult