Preclinical model of anterior circulation intracranial stenting

Preclinical testing of intracranial stents is currently performed in the peripheral circulation, and rarely in the basilar artery of the dog.

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.

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.

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.

We describe a new preclinical model of intracranial stenting in the MCA. Such a model may prove useful for evaluating new surface modifications.