Factors that determine penumbral tissue loss in acute ischaemic stroke

Abstract

The goal of acute stroke treatment with intravenous thrombolysis or endovascular recanalization techniques is to rescue the penumbral tissue. Therefore, knowing the factors that influence the loss of penumbral tissue is of major interest. In this study we aimed to identify factors that determine the evolution of the penumbra in patients with proximal (M1 or M2) middle cerebral artery occlusion. Among these factors collaterals as seen on angiography were of special interest. Forty-four patients were included in this analysis. They had all received endovascular therapy and at least minimal reperfusion was achieved. Their penumbra was assessed with perfusion- and diffusion-weighted imaging. Perfusion-weighted imaging volumes were defined by circular singular value decomposition deconvolution maps (Tmax > 6 s) and results were compared with volumes obtained with non-deconvolved maps (time to peak > 4 s). Loss of penumbral volume was defined as difference of post- minus pretreatment diffusion-weighted imaging volumes and calculated in per cent of pretreatment penumbral volume. Correlations between baseline characteristics, reperfusion, collaterals, time to reperfusion and penumbral volume loss were assessed using analysis of covariance. Collaterals (P = 0.021), reperfusion (P = 0.003) and their interaction (P = 0.031) independently influenced penumbral tissue loss, but not time from magnetic resonance (P = 0.254) or from symptom onset (P = 0.360) to reperfusion. Good collaterals markedly slowed down and reduced the penumbra loss: in patients with thrombolysis in cerebral infarction 2 b-3 reperfusion and without any haemorrhage, 27% of the penumbra was lost with 8.9 ml/h with grade 0 collaterals, whereas 11% with 3.4 ml/h were lost with grade 1 collaterals. With grade 2 collaterals the penumbral volume change was -2% with -1.5 ml/h, indicating an overall diffusion-weighted imaging lesion reversal. We conclude that collaterals and reperfusion are the main factors determining loss of penumbral tissue in patients with middle cerebral artery occlusions. Collaterals markedly reduce and slow down penumbra loss. In patients with good collaterals, time to successful reperfusion accounts only for a minor fraction of penumbra loss. These results support the hypothesis that good collaterals extend the time window for acute stroke treatment.

Multivariate Dynamic Prediction of Ischemic Infarction and Tissue Salvage as a Function of Time and Degree of Recanalization

“…[13][14][15][16][17][18] Furthermore, thresholding does not integrate infarct risk imposed by variables on a patient level such as severity of symptoms at admission, age, and sex. 5,9,19 To combine the independent contributing effect of multiple variables on voxelwise infarct probability, multivariate image analysis has been explored including logistic regression or generalized linear model (GLM). 14,20,21 A multivariate imaging model that contains variables of timing and recanalization status opens the opportunity for dynamic estimation of infarction and salvageable tissue in the context of elapsing time and recanalization status after endovascular treatment.…”

Ipsilateral Prominent Thalamostriate Vein on Susceptibility-Weighted Imaging Predicts Poor Outcome after Intravenous Thrombolysis in Acute Ischemic Stroke

“…[22][23][24] Collateral status is one of the most important factors determining penumbral tissue loss, and good collaterals have been associated with reduced penumbral loss. 13,25 Therefore, we speculated that the presence of IPTSV might indicate poor collaterals after acute ischemia, which would result in increased penumbral tissue loss. However, it is challenging to directly investigate the relationship between IPTSV and leptomeningeal collaterals in our data because we included patients with both largeartery occlusion and more distal occlusions.…”

“…12 The proportion of penumbral tissue loss was defined as described previously: 100 ϫ (Posttreatment Infarct Volume Ϫ Pretreatment Infarct Volume)/(Pretreatment Hypoperfusion Volume Ϫ Pretreatment Infarct Volume). 13 Large-artery occlusion was defined as occlusion of the internal carotid, proximal middle cerebral (M1), or proximal posterior cerebral (P1) artery. The modified Rankin Scale score was assessed at 3 months and dichotomized into good (0 -2) and poor (3-6) outcomes.…”

Iatrogenic Vessel Dissection in Endovascular Treatment of Acute Ischemic Stroke

“…Our study is based on the Bernese stroke registry, a prospective database on patients with AIS [18][19][20]. Baseline and 3-month outcome data on consecutive AIS patients admitted to the Neurological Department of the University Hospital of Bern are collected.…”