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Background Preclinical testing of intracranial stents is currently performed in the peripheral circulation, and rarely in the basilar artery of the dog. Objective To test the feasibility of intracranial stenting in the middle cerebral artery (MCA) of the dog and explore the use of MRI to detect thromboembolic complications. Methods Six purpose-bred cross-hound dogs were used for proof-of-concept stenting of both MCAs in each animal. Immediately following the procedure, the animals were imaged with MRI. MRI was repeated weekly for 1 month. After the final angiography at 30 days, the animals were euthanized for pathological assessment of the stents and the brain. Results We successfully deployed 12 stents in the MCAs of all animals. We deployed three techniques for microcatheterization of the MCA--namely, directly through the internal carotid artery (ICA), using anastomotic arteries from the external carotid artery, or via the contralateral ICA through the anterior communicating artery. Two iatrogenic perforations of the ICA with formation of an arteriovenous fistula occurred, without clinical sequelae, which spontaneously resolved on follow-up. All animals tolerated the procedure and completed the follow-up surveillance. MRI revealed procedural thromboembolic induced areas of restricted diffusion, and only one instance of a delayed thromboembolic lesion during surveillance. At follow-up angiography, the devices were all patent. Conclusion We describe a new preclinical model of intracranial stenting in the MCA. Such a model may prove useful for evaluating new surface modifications. [ABSTRACT FROM AUTHOR]

Background High-frequency optical coherence tomography (HF-OCT) is an intravascular imaging method that allows for volumetric imaging of flow diverters in vivo. Objective To examine the hypothesis that a threshold for both volume and area of communicating malapposition can be predictive of early aneurysm occlusion. Methods Fifty-two rabbits underwent elastase aneurysm formation, followed by treatment with a flow diverter. At the time of implant, HF-OCT was acquired to study the rate and degree of communicating malapposition. Treated aneurysms were allowed to heal for either 90 or 180 days and euthanized following catheter angiography. Healing was dichotomized into aneurysm remnant or neck remnant/complete occlusion. Communicating malapposition was measured by HF-OCT using a semi-automatic algorithm able to detect any points where the flow diverter was more than 50 µm from the vessel wall. This was then summed across image slices to either a volume or area. Finally, a subsampled population was used to train a statistical classifier for the larger dataset. Results No difference in occlusion rate was found between device type or follow-up time (p=0.28 and p=0.67, respectively). Both volume and area of malapposition were significantly lower in aneurysms with a good outcome (p<0.001, both). From the statistical model, a volume of less than 0.56 mm3 or a normalized area less than 0.69 as quantified by HF-OCT was predictive of occlusion (p<0.001, each). Conclusions HF-OCT allows for measurements of both volume and area of malapposition and, from these measurements, an accurate prediction for early aneurysm occlusion can be made. [ABSTRACT FROM AUTHOR]