Does Diffusion Lesion Volume Above 70 mL Preclude Favorable Outcome Despite Post-Thrombolysis Recanalization?

Abstract

Background and Purpose-Whether to withhold recanalization treatment when the diffusion-weighted imaging (DWI) lesion exceeds a given volume is unsettled. Our aim was to assess the impact of recanalization on outcome in patients with baseline DWI lesion ≥70 mL (DWI≥70 mL) treated ≤4.5 hours from onset. We hypothesized that recanalization is beneficial in a sizeable fraction of these patients and that this is associated with a larger DWI lesion reversal. Methods-We analyzed 267 consecutive patients treated with intravenous recombinant tissue-type plasminogen activator for middle cerebral artery territory stroke in whom an occlusion was present on magnetic resonance angiography and 24-hour recanalization and 90-day clinical outcome could be assessed. After stratification relative to the 70-mL DWI lesion cut point, we calculated the odds ratio for recanalization of the primary arterial occlusive lesion (AOL score ≥2) to predict favorable outcome (modified Rankin scale score ≤2). DWI lesion reversal was compared between recanalizers with DWI≥70 mL with favorable and unfavorable outcomes. Results-Median (interquartile range) DWI lesion volume was 22 mL (10-60), and median onset time to imaging was 116 minutes (86-151). Twelve (22%) of the 54 patients with DWI≥70 mL experienced favorable outcome, of which 9 had recanalized. In patients with DWI≥70 mL, recanalization was significantly associated with favorable outcome after adjustment for age and National Institutes of Health Stroke Scale (odds ratio =4.

Impact of Initial Diffusion-Weighted Imaging Lesion Growth Rate on the Success of Endovascular Reperfusion Therapy

“…Also, we do hypothesize based on the results of previous studies that in addition to the prevention of the infarct progression, part of the beneficial effect may also be related to the reversal of the acute DWI lesion. 14 Our study has several limitations. First, a successful recanalization was achieved only among 55% of the cases when it was reported up to 30% higher in the recent thrombectomy trials.…”

Is there a benefit of mechanical thrombectomy in patients with large stroke (DWI‐ASPECTS ≤ 5)?

“…Only two patients with DWI-ASPECTS 0À2 achieved good neurological outcome after recanalization. They were recanalized very early and their neurological recovery may be associated with a large amount of DWI lesion reversal [15,18]. A previous study showed that DWI-ASPECTS thresholds of <4 and ≥7 may be used as reliable surrogates of DWI lesion volumes of >100 and <70 ml, respectively [19].…”

Combined Evaluation of Noncontrast CT ASPECTS and CT Angiography Collaterals Improves Detection of Large Infarcts in Proximal Artery Occlusive Stroke

“…Many of these patients had larger ischemic cores than allowed by DAWN, up to 70 mL. Based on recent studies, it is likely that this ischemic core threshold can be further increased, as patients with infarcts greater than 70 mL have been shown to derive an endovascular reperfusion benefit . Therefore, the combined NCCT‐ASPECTS/CTA‐collateral selection strategy may expand treatment to patients with core volumes between 70 and 100 mL.…”