Preclinical ischemic stroke is at the crossroads in search of reliable and robust simulation models as past experiences with their translation from the laboratory to the standard of clinical care have often been disappointing. The efficacy of neuroprotective agents is still elusive, and the use of thrombolytics alone is limited to the narrow time window of presentation from the onset of the deficit. Hence, the focus has shifted to interventional revascularization to salvage the parenchyma at the risk of infarction. As the burden of disease morbidity and mortality is so enormous, neurointerventionalists have adopted a more aggressive approach to mechanical revascularization with the limited approved tools available-the Penumbra and the MERCI retrieval system, and the recently incorporated stent retrievers. In fact, the interventional space is among the fastest growing fields in stroke research today. Assessing treatment efficacy in these scenarios is infinitely complex as the heterogeneity of the cerebrovasculature, physical and mechanical nature of the occlusive embolus and the time of presentation are all confounders in assessing treatment outcomes. As no single thromboembolic model is apt to address all of these questions, an integrated methodology with a combination of both in vitro and in vivo assessment needs to be adopted. This involves clinically relevant thromboembolic analogs in device evaluation in vascular replicas, thromboembolic stroke induction in large animal gyrencephalic ischemic stroke models for thrombolytic, imaging and neuroprotection research and a native cerebrovascular target for evaluation of the safety and efficacy of mechanical thrombectomy devices.

Objective To investigate the impact of coil design on the distribution of the coil mass in a controlled in vitro experiment. A secondary objective was to study the relationship between angiographic occlusion, packing density and coil mass uniformity. Methods Seven silicon side wall aneurysm models were embolized in each arm with a different coil design under fluoroscopic guidance. Packing density calculations and scoring of the angiographic occlusion were made. The models were embedded in epoxy and sectioned through the aneurysm neck and the dome. The sections were imaged and processed to derive the fractional surface area of coil material over the coil free area, a quantitative endpoint representing the percentage of the given region of interest consumed by coils. The SD of the surface area fractions is inversely proportional to the uniformity of coil distribution. Results The novel triangular primary wind design of the Deltapaq achieved a more homogenous distribution of coils within the aneurysm dome compared with the helical and complex microcoil systems (p¼0.018). The packing density achieved by the Deltapaq (39.161.6%) was significantly higher than the complex (35.262.8%) and the helical (32.263.3%) coils. Angiographically, aneurysms coiled by the Deltapaq were more likely to obtain a Raymond score of class I. Conclusion Evaluation of emerging coil technologies with respect to treatment durability may be well served by an assessment of their uniformity of distribution within an aneurysm in addition of the traditional packing density and angiographic occlusion scoring methods.

BACKGROUND AND PURPOSE:Previous studies have shown the feasibility of assessing qualitative CBV measurements in the angiography suite by using FPD-CBCT systems. We have investigated the correlation of FPD-CBCT CBV lesion volumes to the infarct volume.

BACKGROUND AND PURPOSE:Intracranial aneurysms treated by coiling have a risk for recurrence, requiring surveillance imaging. MRA has emerged as an attractive technique for postcoiling aneurysm imaging. Previous research has evaluated MR imaging artifacts of the coil mass in vitro. Our aim in this study was to evaluate MR imaging artifacts of coiled aneurysms in vivo with time.

Background and purposeRecanalization strategies mediated by intra-arterial fibrinolytic therapy in combination with mechanical clot disruption may be a more effective treatment approach than either therapy used alone. There are few preclinical animal models to evaluate these strategies. Here we report on a model to simultaneously evaluate both of these treatment approaches.MethodsAllogeneic clot was injected through the 6 F guide catheter after creating >50% luminal stenosis of the common carotid arteries of New Zealand White rabbits. The stenosis was released after 1 h, allowing sufficient time for clot–vessel wall interaction. Occlusion was confirmed and each vessel was assigned to receive either balloon angioplasty alone, intra-arterial tissue plasminogen activator (tPA, Alteplase, Genentech, San Francisco, California, USA), tPA delivery through prototype balloon infusion wire (NIT Therapeutics, Pittsburgh,  Pennsylvania, USA), partial stent deployment or partial stent deployment with locally delivered tPA. The negative control received no treatment.ResultsIn vivo revascularization Thrombolysis in Cerebral Infarction (TICI) score revealed that the balloon infusion wire achieved a stable and higher revascularization score of TICI 2B, with a lower dose of tPA in comparison with other treatment strategies. All treatment strategies resulted in endothelial denudation and exposure of the internal elastic lamina.ConclusionsThe proposed animal model permits reliable and consistent thromboembolic occlusion of the target vasculature and allows for an assessment of both pharmacologic and mechanical revascularization strategies for acute ischemic stroke.