Anterior Internal Vertebral Venous Plexus Research Articles

Extracranial prevertebral venous network of the craniocervical junction: CT-digital subtraction venography analysis

Although the craniocervical junction has a complex anatomical structure associated with clinical diseases, its ventral venous network has not been well studied. This study aimed to clarify the extracranial ventral venous structure at the craniocervical junction. Head computed tomography digital subtraction venography (CT-DSV) images of 273 patients (age 6months to 93years) taken at our department were retrospectively analyzed. We analyzed the frequency and anatomical features of the venous channels, as well as their upstream and downstream connections with the surrounding channels at the ventral craniocervical junction, from the level of the hypoglossal canal to the second cervical vertebra. In 54% of the cases, the vein descended from the anterior condylar confluence, running medially along the basioccipital and fusing with its counterpart in the midline at the level of the atlanto-occipital membrane. Furthermore, 24% of this vein was connected caudally to the anterior external vertebral venous plexus. We also identified venous channels, either as a sole vein or venous plexus, on the tip of the odontoid process (10%), which has not been well described previously. The vein around the odontoid process was connected to several veins, including the aforementioned vein anterior to the condyle and the anterior internal vertebral venous plexus. CT-DSV analysis revealed a detailed venous architecture ventral to the craniocervical junction. Venous structures identified in this study may be involved in diseases in this area.

Intracranial Connections of the Vertebral Venous Plexus: Anatomical Study with Application to Neurosurgical and Endovascular Procedures at the Craniocervical Junction.

Descriptions of intracranial extensions of vertebral venous plexuses are lacking. To identify vertebral venous plexuses at the craniocervical junction in cadavers and describe them. The authors dissected 15 ink-injected, formalin-fixed, adult cadaveric heads and measured cranial extensions of the spinal venous plexuses. All specimens had vertebral venous plexuses at the craniocervical junction composed of multiple interwoven vessels concentrated anteriorly (anterior vertebral plexuses), posteriorly (posterior vertebral venous plexuses), and laterally (lateral vertebral venous plexuses). Veins making up the plexus tended to be largest for the anterior internal vertebral venous plexus. On 33%, a previously unnamed lateral internal vertebral venous plexus was identified that connected to the lateral marginal sinus. The anterior external vertebral venous plexus connected to the basilar venous plexus via transclival emissary veins in 13%; remaining veins connected either intracranially via small perforating branches through the anterior atlanto-occipital membrane (33%) or had no direct gross connections inside the cranium (53%). The anterior internal vertebral plexus, which traveled between layers of the posterior longitudinal ligament, connected to the anterior half of the marginal sinus in 33% and anterolateral parts of the marginal sinus in 20%. The posterior internal venous plexus connected to the posterior aspect of the marginal sinus on 80% and into the occipital sinus in 13.3%. The posterior external venous plexus connected to veins of the hypoglossal canal in 20% and into the posterior aspect of the marginal sinus in 13.3%. Knowledge of these connections is useful to neurosurgeons and interventional radiologists.

Idiopathic hypertrophic pachymeningitis with intracranial hypotension and distension of anterior internal vertebral venous plexus are associated with positional headaches but not sufficient in the diagnosis

Idiopathic hypertrophic pachymeningitis (IHP) is a very infrequent disorder that causes a localized or diffuse thickening of the dura mater. The main clinical features of IHP at presentation include headache, cranial nerve involvement, ataxia, transient ischemic attacks (TIA) and seizures. Intracranial hypotension (ICH) and distension of anterior internal vertebral venous plexus (IVVP) have not previously been reported as the main clinical manifestations. We report a unique case with these characteristics as the main clinical findings, and investigate the internal relationship between these characteristics. This study highlights the heterogeneity of IHP, in terms of clinical, imaging, and pathological features. We recommend that dural biopsies should be considered in patients with clinically typical orthostatic headache and (or) diffuse pachymeningeal enhancement on magnetic resonance imaging (MRI) for the diagnosis of IHP.

Reconstruction tridimensionnelle des plexus veineux vertébraux internes et antérieurs d’un fœtus humain : étude de faisabilité

Anterior internal vertebral venous plexus have been studied extensively due to their clinical importance in diseases of the spine and obstruction of the inferior vena cava. The aim of this feasibility study was to reconstruct in 3D the lower thoracic area of the anterior epidural space of a 69 mm (crown-rump) human fetus from the Rouvière Collection, circa 1927. Forty slices (spaced by 40 microm) at the level of the tenth and eleventh thoracic vertebrae, and their lower adjacent intervertebral discs, were reconstructed in 3D using the commercial software SURFdriver. In a preliminary study, we had found that the structures of the epidural space are already formed at this stage of development, and that they are comparable to the adult stage (2002). Reconstruction of the microscopic slices in 3D allowed to better visualize spatially the structures of the venous plexus and their anatomical relationships. This technique could be used as a complement to the classically used histological studies.

Craniocervical junction venous anatomy around the suboccipital cavernous sinus: evaluation by MR imaging

The present study evaluated the venous anatomy of the craniocervical junction, focusing on the suboccipital cavernous sinus (SCS), a vertebral venous plexus surrounding the horizontal portion of the vertebral artery at the skull base. MR imaging was reviewed to clarify the venous anatomy of the SCS in 33 patients. Multiplanar reconstruction MR images were obtained using contrast-enhanced three-dimensional fast spoiled gradient-recalled acquisition in the steady state (3-D fast SPGR) with fat suppression. Connections with the SCS were evaluated for the following venous structures: anterior condylar vein (ACV); posterior condylar vein (PCV); lateral condylar vein (LCV); vertebral artery venous plexus (VAVP); and anterior internal vertebral venous plexus (AVVP). The SCS connected with the ACV superomedially, with the VAVP inferolaterally, and with the AVVP medially. The LCV connected with the external orifice of the ACV and superoanterior aspect of the SCS. The PCV connected with the posteromedial aspect of the jugular bulb and superoposterior aspect of the SCS. The findings of craniocervical junction venography performed in eight patients corresponded with those on MR imaging, other than with regard to the PCV. Contrast-enhanced 3-D fast SPGR allows visualization of the detailed anatomy of these venous structures, and this technique facilitates interventions and description of pathologies occurring in this area.

The So-Called Anterior Meningeal Artery: An Anatomic Study for Treatment Modalities

The so called anterior meningeal artery (AMA) is a branch of the vertebral artery (VA), which had been interpreted as a supplying vessel of the dura in the foramen magnum and upper cervical level. In this study, we examined the anatomy of this artery and relationships to its surrounding structures for treatment modalities. With the aid of magnification, five adult cadaveric head and neck complex and five cervical spines were examined after perfusion of the vessels with colored silicone. The AMA arose from the VA between the C2 and C3 level, and passed medially through the intrervertebral foramen anterior to the dural sheath of the third cervical nerve root. It ran upwards dorsal to the deep layer of the posterior longitudinal ligament (PLL) with anterior internal vertebral venous plexus. Rostrally, it formed an arcade above the apex of the odontoid process with its contralateral mate. The AMA gave off several tiny branches to the deep layer of the PLL, ligaments and soft tissues above the apex of the odontoid process, and vertebral bodies of the axis. At the level of the foramen magnum, it ended in several small twigs to the dura. Anastomoses between the AMA system and adjacent vessels were observed. One was directed through the hypoglossal canal to the ascending pharyngeal artery and the other was with the V3 segment of the VA. The origin and course of the two AMA, and anastomoses were symmetric. Although the AMA feeds the ventral dura of the foramen magnum, the perfusion area is larger than its name suggests, including the bony and ligamentous structures in the craniovertebral junction. Anatomical knowledge of the AMA, including its anastomoses and layer relationships to the surrounding structures, may help to perform treatment modalities in this region rationally.

Assessment of lumbar spinal canal stenosis by magnetic resonance phlebography

AbstractThere is evidence to suggest that cauda equina intermittent claudication is caused by local circulatory disturbances in the cauda equina as well as compression of the cauda equina. We evaluated the role of magnetic resonance phlebography (MRP) in identifying circulatory disturbances of the vertebral venous system in patients with lumbar spinal canal stenosis. Extensive filling defects of the anterior internal vertebral venous plexus were evident in patients with lumbar spinal canal stenosis (n = 53), whereas only milder abnormalities were noted in patients with other lumbar diseases (n = 16) and none in normal subjects (n = 13). The extent of the defect on MRP correlated with the time at which intermittent claudication appeared. In patients with lumbar spinal canal stenosis, extensive defects of the internal vertebral venous plexus on MRP were noted in the neutral spine position, but the defect diminished with anterior flexion of the spine. This phenomenon correlated closely with the time at which intermittent claudication appeared. Our results highlight the importance of MRP for assessing the underlying mechanism of cauda equina intermittent claudication in patients with lumbar spinal canal stenosis and suggest that congestive venous ischemia is involved in the development of intermittent claudication in these patients.

Microsurgical Anatomy of the Lower Cervical Spine and Cord

The authors dissected the cervical spine and its surrounding structures from 40 adult cadavers under a surgical microscope. The anterior part of the spine and spinal cord was examined after vertebrectomy. The posterior longitudinal ligament (PLL) consists of two layers; the anterior one is termed the deep layer, and the posterior one is termed the superficial layer. These two layers adhered together loosely. In the lateral portion of the spinal canal, the superficial layer joined the periradicular sheath at the level of the intervertebral disc spaces and joined the dura mater at the level of the vertebral bodies. After the removal of the deep layer, the anterior internal vertebral venous plexus was seen on top of the lateral part of the superficial layer. The venous plexus was embedded between the double-layered PLLs, was not located in the epidural space, and was not seen in the medial part of the PLL. The PLL without venous channels on top of it was about 10 mm in width at the levels of the intervertebral disc and about 5 mm at the levels of the vertebral body. The anterior root exit zone (AREZ) was an elliptical shape; the transverse length of the AREZ was about 2 mm, and the longitudinal length was 10 to 15 mm. The average number of anterior rootlets on the AREZ was 17 to 25 and tended to decrease in the lower cervical spinal cord. The posterior structures were examined after en bloc laminectomy.(ABSTRACT TRUNCATED AT 250 WORDS)

Demonstration of vertebral body end plate veins by magnetic resonance imaging.

The venous drainage of the vertebral end plate capillary bed is via a plexus of post-capillary venules in the subchondral region, which drains into a horizontal subarticular collecting vein. This vein then joins the anterior internal vertebral venous plexus. There are also anastomotic connections through vertical tributaries to the basi-vertebral system of veins (Crock et al, 1973; Crock, 1983) (Fig. 1). The end plate venous plexus may be important in the pathogenesis of symptoms in the syndrome of internal disc disruption, in which catabolites and disc proteins leak out of the disc into the systemic circulation via the end plate veins, producing local and systemic features of hypersensitivity reactions (Gurdjian et al, 1961; Nachemson, 1969; Crock, 1970). The plexus is also important in maintaining the integrity of the normal intervertebral disc, as diffusion of nutrients takes place across the end plates (Urban et al, 1976; Bernick & Caillet, 1982). Although demonstrated in dogs and post-mortem specimens, the end plate veins have not previously been demonstrated by in vivo imaging.