The dural crossing of the vertebral artery

Abstract

The aim of this study was to present the anatomic and macroscopic aspects of the vertebral artery at the level of the dural crossing. Twenty vertebral arteries in 10 cadavers were dissected. The preparations were photographed and all the samples at the level of the dural crossing were submitted to a histologic study. Macroscopic results allow specification of the relationships between the dural crossing of the vertebral artery and the nervous elements (C1 and C2 nerves, mixed nerves), the vascular elements (postero-inferior cerebellar artery), the dural sheath and the first two dentate ligament tips. Microscopic results show the intricate relationship of the different layers of the vertebral artery with the dura at its crossing. Dural fibers reinforce the adventitial fibers not only by continuing them in their contact, much as the pages of a book, but also by being encrusted into the adventitia up to the tunica media, thus creating a very efficient mooring system. This work provides some information for an understanding of the symptoms induced by foramen magnum meningiomas and the onset of clinical signs after the surgical excision of these tumors. It also explains why dissections of the suboccipital segment of the vertebral artery stop at the level of the dural crossing, and never spread towards the intracranial segment.

Outcomes and prognostic factors of intracranial unruptured vertebrobasilar artery dissection

“…Bilateral VA dissection did not affect the clinical course. 15,16 Because the elastic tissue is responsible for the integrity of the arterial wall, such histologic differences in the intracranial artery may affect the lesion morphology of VBD. 10 Aneurysmal dilatation was more frequent than steno-occlusive type in the angiographic evaluation of the siu-VBD.…”

Endovascular Treatment of Intracranial Vertebral Artery Dissection

“… 61 , 62) One possible explanation for such difference in lesion type was the absence of external elastic lamina and decreased amount of medial elastic tissue in the intradural artery. 63 , 64) Subintimal dissection tends to result in luminal stenosis or occlusion, whereas subadventitial dissection often causes dilatation. 1) The primary lesion shape of symptomatic intracranial VADs might differ between unruptured and ruptured cases.…”