Carotid pseudo-occlusion on CTA in patients with acute ischemic stroke: A concerning observation

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102

100

T reatment of patients with acute ischemic stroke (AIS) is aimed at reopening occluded arteries and reestablishment of intracranial perfusion. Determining pivotal characteristics about the occluding thrombus using available imaging has the potential to improve patient's diagnostics and prognostics.Background and Purpose-Preclinical studies showed that thrombi can be permeable and may, therefore, allow for residual blood flow in occluded arteries of patients having acute ischemic stroke. This perviousness may increase tissue oxygenation, improve thrombus dissolution, and augment intra-arterial treatment success. We hypothesize that the combination of computed tomographic angiography and noncontrast computed tomography imaging allows measurement of contrast agent penetrating a permeable thrombus, and it is associated with improved outcome. Methods-Thrombus and contralateral artery attenuations in noncontrast computed tomography and computed tomographic angiography images were measured in 184 Multicenter Randomized Clinical trial of Endovascular treatment of acute ischemic stroke in the Netherlands (MR CLEAN) patients with thin-slice images. Two quantitative estimators of the thrombus permeability were introduced: computed tomographic angiography attenuation increase (Δ) and thrombus void fraction (ε). Patients were dichotomized as having a pervious or impervious thrombus and associated with outcome, recanalization, and final infarct volume. Results-Patients with Δ≥10.9 HU (n=81 [44%]) and ε≥6.5% (n=77 [42%]) were classified as having a pervious thrombus.These patients were 3.2 (95% confidence interval, 1.7-6.4) times more likely to have a favorable outcome, and 2.5 (95% confidence interval, 1.3-4.8) times more likely to recanalyze, for Δ based classification, and similarly for ε. These odds ratios were independent from intravenous or intra-arterial treatment. Final infarct volume was negatively correlated with both perviousness estimates (correlation coefficient, −0.39 for Δ and −0.40 for ε). Conclusions-This

Section: Discussionmentioning

confidence: 99%

Section: Strokementioning

confidence: 99%

Thrombus Permeability Is Associated With Improved Functional Outcome and Recanalization in Patients With Ischemic Stroke

Santos

Marquering

Blanken

et al. 2016

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102

100

“…One difficulty with this exclusion is that differentiating complete cervical carotid occlusion from a distal ICA occlusion is often not possible on CTA or MRA. 37 The number of patients with cervical carotid occlusion or stenosis was not consistently reported but was substantial, ranging from 18.6% (REVASCAT) to 32.2% (MR CLEAN). Stenting of the underlying stenosis or occlusion was discouraged in the ESCAPE protocol.…”

Section: Strokementioning

confidence: 99%

2015 American Heart Association/American Stroke Association Focused Update of the 2013 Guidelines for the Early Management of Patients With Acute Ischemic Stroke Regarding Endovascular Treatment

Powers¹,

Derdeyn²,

Biller³

et al. 2015

1,906

1,205

3020Purpose-The aim of this guideline is to provide a focused update of the current recommendations for the endovascular treatment of acute ischemic stroke. When there is overlap, the recommendations made here supersede those of previous guidelines. Methods-This focused update analyzes results from 8 randomized, clinical trials of endovascular treatment and other relevant data published since 2013. It is not intended to be a complete literature review from the date of the previous guideline publication but rather to include pivotal new evidence that justifies changes in current recommendations. Members of the writing committee were appointed

“…Yet, CTA could result in incomplete filling of the thrombus because of timing limitations, hemodynamic restrictions, or pseudo-occlusions, causing an underestimation of the potential maximal attenuation increase in CTA. 17,18 For a more reliable measurement, thinly reconstructed dynamic CTA imaging 19,20 could be a valuable alternative. Also, in this cohort, most CTA were acquired after CT perfusion scanning.…”

Section: August 2016mentioning

confidence: 99%

Permeable Thrombi Are Associated With Higher Intravenous Recombinant Tissue-Type Plasminogen Activator Treatment Success in Patients With Acute Ischemic Stroke

Santos¹,

Dankbaar²,

Treurniet³

et al. 2016

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Early complete recanalization of an occluded artery is a strong predictor of favorable functional outcome in patients with acute ischemic stroke.1 To increase the chance of favorable outcome, guidelines recommend the use of intravenous thrombolysis with recombinant tissue-type plasminogen activator (r-tPA) in eligible patients.2 Because intravenous r-tPA treatment results in a relatively low rate of recanalization, 3 it might be useful to estimate the likelihood of failure or success of intravenous r-tPA before treatment initialization.Preclinical studies have shown that thrombus permeability influences r-tPA efficacy. Permeability reflects the ability of soluble molecules to move within the gaps between adjacent platelets, fibrin filaments, and red blood cells.4,5 A high permeability might result in more effective activation of recombinant tissue-type plasminogen because of an improved surface contact area and might, therefore, increase the dissolution of the fibrin filaments and consequently the thrombus.6 These preclinical findings have not yet been studied in a clinical setting. We recently proposed a method to assess thrombus Background and Purpose-Preclinical studies showed that thrombus permeability improves recombinant tissue-type plasminogen activator (r-tPA) efficacy. We hypothesize that thrombus permeability estimated from radiological imaging is associated with improved recanalization after treatment with intravenously administered r-tPA (r-tPA) and with better functional outcome. Methods-We assessed thrombus attenuation increase (TAI) in patients from the Dutch Acute Stroke Study with an occlusion of an intracranial artery on computed tomographic angiography. Patients were included within 9 hours after the stroke onset. After dichotomization of TAI as pervious or impervious, logistic regressions analyses were performed to estimate associations of intravenous r-tPA therapy with complete recanalization and with favorable functional outcome (modified Rankin Scale score of ≤2). Results-Three hundred eight patients matched the inclusion criteria. The median TAI was 20.1 (interquartile range, 8.5-37.8) Hounsfield unit (HU). We found a significant increase in the odds of complete recanalization with increasing TAI for patients treated with intravenous r-tPA (P=0.030). One hundred thirty-one (42%) thrombi were classified as pervious with TAI of ≥23 HU. In patients with a pervious thrombus, complete recanalization was more frequent after treatment with intravenous r-tPA than after conservative treatment (odds ratio, 6.26; 95% confidence interval, 2.4-16.8; P<0.001). In patients with an impervious thrombus, the effect of intravenous r-tPA was not significant (odds ratio, 1.4; 95% confidence interval, 0.5-4.1; P=0.47). Favorable outcome was more common in patients with a pervious thrombi than without (odds ratio, 2.1; 95% confidence interval, 1.3-3.4; P=0.001). Conclusions-Thrombus perviousness, as measured on computed tomography in the acute stage of ischemic stroke, is strongly associated with recanalization...