Anatomy, Imaging and Surgery of the Intracranial Dural Venous Sinuses

R. Shane Tubbs

• Editore: Elsevier
• Anno: 2019
• ISBN:
  9780323681933
• Argomento: Medizin
• Categoria: Neurochirurgie

This first-of-its-kind volume focuses on the anatomy, imaging, and surgery of the dural venous sinuses and the particular relevance to neurosurgery and trauma surgery. Knowledge of the fine clinical anatomy involved in neurosurgery and skull base surgery has progressed greatly in recent years, and this title reflects new information of particular importance to neurosurgeons, trauma surgeons, neurologists, interventional radiologists, and others who need a complete, up-to-date understanding of this complex anatomical area.

• Provides thorough coverage of the clinical anatomy of the dural venous sinuses, highlighted by 250 clear, high-quality illustrations and clinical photographs.
• Covers imaging techniques and surgery in separate chapters following extensive anatomy coverage.
• Presents the knowledge and experience of recognized experts and authors in the field.
• Consolidates today's available information and guidance into a single, convenient resource.

Chapter 1

The Embryology of the Dural Venous Sinus

An Overview

Lexian McBain, Oded Goren, and R. Shane Tubbs

Abstract

The development of the intracranial venous sinuses has not been well studied. Our knowledge of this complex embryology has been contributed to by researchers such as Streeter and Padget in the first half of the 20th century. As malformations of the vasculature of the cranium are encountered by various physicians (e.g., neurologists, radiologists, neurosurgeons), a good working knowledge of this embryology is important. This chapter reviews the development of the intracranial dural venous sinuses and includes simplified illustrations that demonstrate the major steps in this process.

Keywords

Anatomy; Brain; Embryology; Skull; Veins; Venous drainage

Introduction

This review describes the embryologic development of the dural venous sinuses at different stages. It begins at the earliest stage with identification of the first venous structure and summarizes the development of the morphologic architecture of the dural sinuses. Data concerning the contribution of embryology were collected from authors such as Streeter and Padget, who comprehensively examined the Carnegie Institute’s Mall Collection of a series of human embryos from 4 to 80 mm. Clinical correlations are made by examining malformations arising from developmental defects such as the vein of Galen aneurysm and arteriovenous malformation.

The main pattern of the dural sinuses is well established by the time the fetus reaches a length of 40 mm and is refined by the time it reaches 80 mm, ¹ but the final arrangement even at birth does not necessarily fit the standard anatomical descriptions, partly because of the postnatal ossification of the skull. ^2,3 A mesodermal mantle surrounds the developing nervous system and separates into three meningeal layers, each containing a distinct vascular pattern. ¹ The dura mater will relate to the dural venous sinuses. There is extensive remodeling including the formation of new channels and resorption of old ones as the embryo develops. ¹ Padget describes the evolution of cranial venous channels as an orderly sequence logically related to the changing environment like that of corresponding arteries. ¹

First Venous Vascular Structures

At 4 mm embryo (Fig. 1.1) length, the first vascular venous structure can be identified: the primordial vena capitis medialis. It is formed by the merging of the anterior cerebral vein, the maxillary vein, and the pituitary vein. It lies on the walls of the neural tube and runs medial to the trigeminal ganglion and the developing otic vesicle, whereas its caudal end proceeds laterally toward the surface of the embryo. ¹

The vena capitis medialis and the vena capitis lateralis are referred to together as the primary head vein, ⁴ and it constitutes the main channel of the developing embryo. Structurally, it first consists of a single layer of endothelial cells. ⁵ The most lateral part of the vena capitis medialis between the ganglia of cranial nerves V and VII is referred to as the posttrigeminal vein, and it joins the prootic vein before it continues caudally as the vena capitis lateralis. ¹ At this stage, the primary head vein can be considered as having three portions: the vena capitis medialis, the posttrigeminal vein, and the vena capitis lateralis. ⁵

The primary head vein receives many tributaries that aggregate into the three vascular plexuses of the meninges. ¹ These drain mainly the dorsal and ventral portions. ⁴ The anterior group comes from the area of the diencephalon and mesencephalon. ⁴ Between the trigeminal and the acoustic facial complex is the middle or cerebellar portion, and in the neighborhood of the vagus nerve rootlets is the occipital or posterior group, as it bends sharply down into the neck region and drains into the duct of Cuvier. ⁴ This portion joins the cardinal vein to become the anterior cardinal vein and goes on to form the internal jugular vein. The cranial portion medial to the trigeminal ganglion will become the cavernous sinus. At this point, the only ventral contribution to the primary head vein is the primitive maxillary vein, which enters medial to the ganglion of the trigeminal nerve. ¹

Embryo at 10 mm

At around 10–14 mm, the mesenchyme around the sides and base of the brain has the developing dura mater and the chondrocranium. ¹ There is also a separation between the superficial tributaries of the primary head vein and the deeper veins that drain the capillary sheets immediately surrounding the brain tube. ⁴ The ventral portion is completely separated from the deeper-lying plexuses of the neural tube.

Fig. 1.1 Dural venous sinus development at stage 13, day 28, approximately 4–6 mm.

We can now see that the primary head vein is outside the dura mater and distinguish the veins of the dura mater from the cerebral veins, the former being the veins that form the dural venous sinuses. ⁴ At this point, the large channels do not cross the midline except at three points where the vessels appear to be bilaterally asymmetrical, anastomosing with the plexus on the opposite side. These points are (1) the caudal end of the roof of the fourth ventricle; (2) the junction of the midbrain and the hindbrain; and (3) over the diencephalon in the area along the caudal margin of the cerebral hemisphere.

Vein of Galen and the Straight Sinus

The choroid plexus, which develops much more rapidly than the cortical mantle, initially drains into the inferior choroidal vein. It is soon drained by the superior choroidal vein, which is the continuation of the primitive internal cerebral vein. At this early stage, there is only one very small thalamic extension. These bilateral internal cerebral veins fuse posteriorly into what will become the vein of Galen and the straight sinus. ¹

Embryo at 18 mm

The flow of the plexuses changes: the flow of the middle plexus travels into the posterior plexus owing to an anastomosis between the two plexuses that runs dorsal to the otic capsule and lateral to the endolymphatic sac ¹ (Fig. 1.2). This then becomes the sigmoid sinus. ⁴ Drainage from the cerebellar region and the posterior part of the midbrain now travels directly into the channel to the posterior plexus.

The supraoptic vein, which will become the superior ...