Large Volumes of Critically Hypoperfused Penumbral Tissue Do Not Preclude Good Outcomes After Complete Endovascular Reperfusion

Abstract

R eperfusion therapy remains the mainstay of acute ischemic stroke treatment but its clinical benefit comes at the cost of potential harm from reperfusion injury leading to cerebral edema and hemorrhagic complications. Advanced computed tomography (CT) and magnetic resonance imaging (MRI) techniques have emerged as promising tools to improve treatment selection by excluding patients who are particularly prone to harm and have low chances of benefit. The term Malignant profile was originally proposed by the Diffusion and Perfusion Imaging Evaluation for Understanding Stroke Evolution Study (DEFUSE) investigators to describe imaging patterns of severe cerebral ischemia associated with high likelihood of symptomatic intracranial hemorrhage (SICH) or poor outcome after reperfusion in acute ischemic stroke and was empirically defined as a baseline lesion on diffusion-weighted MRI (DWI) >100 mL or a lesion on Background and Purpose-Acute ischemic stroke patients with large volumes of severe hypoperfusion (T max >10 s>100 mL) on magnetic resonance imaging have a higher likelihood of intracranial hemorrhage and poor outcomes after reperfusion. We aim to evaluate the impact of the extent of T max >10 s CTP lesions in patients undergoing successful treatment. Methods-Retrospective database review of endovascular acute ischemic stroke treatment between September 2010 and March 2015 for patients with anterior circulation occlusions with baseline RAPID CTP and full reperfusion (mTICI 3). The primary outcome was the impact of the T max >10 s lesion spectrum on infarct growth. Secondary safety and efficacy outcomes included parenchymal hematomas and good clinical outcomes (90-day modified Rankin Scale score, 0-2). Results-Of 684 treated patients, 113 patients fit the inclusion criteria. T max >10 s>100 mL patients (n=37) had significantly higher baseline National Institutes of Health Stroke Scale (20.7±3.8 versus 17.0±5.9; P<0.01), more internal carotid artery terminus occlusions (29% versus 9%; P=0.02), and larger baseline (38.6±29.6 versus 11.7±15.8 mL; P<0.01) and final (60.7±60.0 versus 29.4±33.9 mL; P<0.01) infarct volumes when compared with patients without T max >10 s >100 mL (n=76); however, the 2 groups were otherwise well balanced. There were no significant differences in infarct growth (22.1±51.6 versus 17.8±32.4 mL; P=0.78), severe intracranial hemorrhage (PH2: 2% versus 4%; P=0.73), good outcomes (90-day mRS score, 0-2: 56% versus 59%; P=0.83), or 90-day mortality (16% versus 7%; P=0.28). On multivariate analysis, only baseline National Institutes of Health Stroke Scale (odds ratio, 1.19; 95% confidence interval, 1.06-1.34; P<0.01) and baseline infarct core volume (odds ratio, 1.05; 95% confidence interval, 1.02-1.08; P<0.01) were independently associated with T max >10 s>100 mL. There was no association between T max >10 s>100 mL with any PH, good outcome, or infarct growth. Conclusions-In the setting of limited baseline ischemic cores, large T max >10 s lesions on computed tomographic perfusion do not seem to be...

Selection Paradigms for Large Vessel Occlusion Acute Ischemic Stroke Endovascular Therapy

“…However, for the most part, SWIFT-PRIME excluded patients with large volumes of severe hypoperfusion (Tmax >10 s >100 mL). It has been demonstrated that in the setting of limited baseline infarct cores, larger malignant hypoperfusion profiles were not associated with worse outcomes if successful reperfusion was achieved, and thus patients with Tmax >10 s >100 mL could still benefit from ET [16]. Another constraint of PIM selection is the inconsistency of perfusion imaging in identifying truly salvageable ischemic penumbra [17].…”

Automated CT Perfusion Ischemic Core Volume and Noncontrast CT ASPECTS (Alberta Stroke Program Early CT Score)

“…Imaging acquisition parameters have been previously described. 6 This study was approved by the local institutional review board.…”

Mild fever as a catalyst for consumption of the ischaemic penumbra despite endovascular reperfusion

“…The details of the perfusion protocol and post-processing pipeline were elaborated previously ( Dehkharghani et al , 2015a , 2016 ; Lima et al , 2016 ; Nogueira et al , 2016 ; Haussen et al , 2016a ); briefly, all perfusion imaging was processed using a commercial version of a vendor-independent software platform (RAPID version 4.5, iSchemaView, Menlo Park, CA, USA). Voxel-wise thresholding of tissue parametric perfusion maps was performed, including the time-to-maximum ( T max ) of the tissue residue function, which was computed to estimate the critically hypoperfused tissue volume at 6 s delay; cerebral blood flow (CBF, expressed in ml/100g/min) maps at default vendor thresholds of relative (r)CBF <30% of contralateral normal tissues were used for estimation of the irreversibly infarcted core , and the balance of the T max > 6s volume used as the putatively at-risk ischaemic penumbra volume.…”