Early Venous Filling Following Thrombectomy: Association With Hemorrhagic Transformation and Functional Outcome

 Oh great, you described a problem but offered NO SOLUTION.  What the fuck good does that do for any survivor? It's a simple question, what's your answer?

Early Venous Filling Following Thrombectomy: Association With Hemorrhagic Transformation and Functional Outcome

Sophie Elands^1*, Pierre Casimir¹, Thomas Bonnet², Benjamin Mine², Boris Lubicz², Martin Sjøgård³, Noémie Ligot¹ and Gilles Naeije¹

• ¹Department of Neurology, Erasmus Hospital, Université Libre de Bruxelles, Brussels, Belgium
• ²Department of Interventional Neuroradiology, Erasmus Hospital, Université Libre de Bruxelles, Brussels, Belgium
• ³Laboratoire de Cartographie Fonctionnelle du Cerveau, Neuroscience Institute (ULB-Neuroscience Institute), Université Libre de Bruxelles, Brussels, Belgium

Background and Purpose: Previous studies have noted the angiographic appearance of early venous filling (EVF) following recanalisation in acute ischemic stroke. However, the prognostic implications of EVF as a novel imaging biomarker remain unclear. We aimed to evaluate the correlation between EVF with (i) the risk of subsequent reperfusion hemorrhage (RPH) and (ii) the association of EVF on both the NIHSS score at 24 h and functional outcome as assessed with the Modified Rankin Scale (mRS) score at 90 days.(Nothing in this purpose is of any use to getting survivors recovered. Your mentors and senior researchers need to be fired.)

Methods: We conducted a retrospective cohort study of patients presenting with an acute ischemic stroke due to a proximal large-vessel occlusion of the anterior circulation treated by thrombectomy. Post-reperfusion digital subtraction angiography was reviewed to look for EVF as evidenced by the contrast opacification of any cerebral vein before the late arterial phase.

Results: EVF occurred in 22.4% of the 147 cases included. The presence of EVF significantly increased the risk of RPH (p = 0.0048), including the risk of symptomatic hemorrhage (p = 0.0052). The presence of EVF (p = 0.0016) and the absence of RPH (p = 0.0021) were independently associated with a better outcome as defined by the NIHSS difference at 24 h, most significantly in the EVF⁺RPH⁻ group. No significant relationship was however found between either EVF or RPH and a mRS score ≤ 2 at 90 days.

Conclusion: Early venous filling on angiographic imaging is a potential predictor of reperfusion hemorrhage. The absence of subsequent RPH in this sub-group is associated with better outcomes at 24 h post-thrombectomy than in those with RPH.

Introduction

Stroke is the second most common cause of death and the main cause of acquired disability worldwide (1). Over sixty percent of morbidity and mortality related to stroke is due to large vessel occlusion (LVO) (2), which in itself accounts for about 30% of all ischemic strokes (3). The primary therapeutic aim is to rapidly recanalize the occluded vessel in order to restore blood flow and salvage cerebral tissue so as to improve patient outcome. In that context, endovascular thrombectomy (EVT) with or without intravenous thrombolysis substantially reduces disability in selected cases of LVO (4). The benefit of recanalizing treatments must be balanced with procedural risks and LVO stroke complications such as hemorrhagic transformation and reperfusion hemorrhage (RPH), with hemorrhagic transformation occurring in up to 43% of patients (5). These hemorrhagic complications tend to be classified based on their radiological appearance according to the European Cooperative Acute Stroke Study (ECASS II) into parenchymal hematomas (PH) and hemorrhagic infarctions (HI). The incidence of PH after EVT was recently reported to be 6% (6), with PH strongly correlating with early neurological deterioration and poor clinical outcome (7).

Although time is of the essence in achieving recanalization, there has been a recent paradigm shift whereby neuroimaging is gaining center stage in EVT decision-making. It provides an invaluable insight that is both patient-specific and dynamic into the physiological effects of the vessel occlusion, the penumbra at stake and RPH risks. Neuroimaging thus plays a key role in providing a tailored-made risk-benefit calculation for recanalization intervention and prediction of treatment response (8).

Current pre-treatment evaluation techniques include perfusion imaging derived from either computer tomographic (CT) or magnetic resonance imaging (MRI), which allow a quantitative assessment of cerebral blood flow (CBF), cerebral blood volume (CBV), and mean transit time (MTT). These measures help to evaluate the degree of salvageable “penumbra,” in other words the area of brain tissue surrounding the irreversibly damaged “infarcted core” that is at risk of infarction but may still be saved if reperfused. As such, the infarcted core is usually defined on CT as a CBF <30% of normal brain blood flow or on MRI as an apparent diffusion coefficient <620 μm²/s, whereas the area of critical hypoperfusion is identified as MTT of >6 s. The estimated penumbra, otherwise known as mismatch volume, is derived from the difference between these two values. However, in LVO, EVT decision currently relies on perfusion characteristics only when symptom onset exceeds 6 h. There, a favorable mismatch allows to extend the therapeutic window to as far as 24 h post-symptom onset (8). Similarly, perfusion imaging helps to assess the risk of bleeding following EVT, with an increased risk of hemorrhagic transformation in cases with a large ischemic core volume, severe blood flow restriction, blood-brain barrier disruption and poor collateral status (9).

However, within 6 h of symptoms onset in LVO, perfusion imaging is not warranted, preventing its use as prognostic tool for clinical outcome or complications in most of cases. In that context, digital subtraction angiography (DSA) could provide valuable information. As such, there is scarce evidence about the post-recanalization imaging biomarkers available on digital subtraction angiography (DSA). Prominent brain vascularity in the form of capillary blush, arteriovenous shunting and early venous filling (EVF) have been noted immediately after EVT (9). EVF, defined as the contrast opacification of any cerebral vein before the late arterial phase on post-reperfusion DSA, has previously been shown to be associated with an increased risk of subsequent infarction (10–12), a higher rate of reperfusion hemorrhage (RPH) and worse clinical outcomes (10, 13). However, these findings were limited by either outdated recanalisation techniques or small cohort size.

Here, we investigated the association between EVF and RPH, together with its impact on functional prognosis and physiopathological correlations by conducting a retrospective study on the largest cohort to date of patients undergoing thrombectomy for a proximal anterior circulation occlusion.