Development of a Routinely Applicable Imaging Protocol for Fast and Precise Middle Cerebral Artery Occlusion Assessment and Perfusion Deficit Measure in an Ovine Stroke Model: A Case Study.

Andrea Maria Herrmann,Elias Kellner,Horst Urbach,Christoph Maurer,Giorgio Franco Maria Cattaneo,Christoph Mülling,Stephan Meckel,Manuela Wieser,Sebastian Alexander Eiden,Wolf-Dirk Niesen,Jörg Haberstroh,Mukesch Johannes Shah,Johannes Boltze

doi:10.3389/fneur.2019.01113

Abstract

Temporary middle cerebral artery occlusion (MCAO) in sheep allows modeling of acute large vessel occlusion stroke and subsequent vessel recanalization. However, rapid and precise imaging-based assessment of vessel occlusion and the resulting perfusion deficit during MCAO still represents an experimental challenge. Here, we tested feasibility and suitability of a strategy for MCAO verification and perfusion deficit assessment. We also compared the extent of the initial perfusion deficit and subsequent lesion size for different MCAO durations. The rete mirabile prevents reliable vascular imaging investigation of middle cerebral artery filling status. Hence, computed tomography perfusion imaging was chosen for indirect confirmation of MCAO. Follow-up infarct size evaluation by diffusion-weighted magnetic resonance imaging revealed fluctuating results, with no apparent relationship of lesion size with MCAO at occlusion times below 4 h, potentially related to the variable collateralization of the MCA territory. This underlines the need for intra-ischemic perfusion assessment and future studies focusing on the correlation between perfusion deficit, MCAO duration, and final infarct volume. Temporary MCAO and intra-ischemic perfusion imaging nevertheless has the potential to be applied for the simulation of novel recanalization therapies, particularly those that aim for a fast reperfusion effect in combination with mechanical thrombectomy in a clinically realistic scenario.

Highlights

Several recent randomized-controlled trials have shown that endovascular mechanical thrombectomy is highly beneficial for patients with acute ischemic stroke and large vessel occlusion (LVO) [1]
We tested whether digital subtraction angiography (DSA) of the common carotid artery (CCA) with additional superselective views from injection of the right rete mirabile is capable of proofing middle cerebral artery occlusion (MCAO)
For immediate comparative assessment of the vessel status after MCAO on 3D TOF MRA, the middle cerebral artery (MCA) main trunk was electrocoagulated to avoid Magnetic resonance imaging (MRI) artifacts emerging from the clip

Summary

Introduction

Several recent randomized-controlled trials have shown that endovascular mechanical thrombectomy is highly beneficial for patients with acute ischemic stroke and large vessel occlusion (LVO) [1]. Applied porcine and ovine models are more suitable to monitor long-term impact of an intervention, but exhibit a rete mirabile which does not allow direct endovascular access to the middle cerebral artery (MCA) for occlusion (MCAO). Stroke models using these species require surgical access to the MCA. Investigating how the initial diffusion deficit corresponds to final infarct size is another important aspect awaiting clarification

Methods

Results

Conclusion