Tentorial venous anatomy of mice and humans.

Pashayar P Lookian,Jeeva P Munasinghe,Jared S Rosenblum,James G Smirniotopoulos,Anthony Cappadona,Vibhu Chandrashekhar,Jean-Paul Bryant,Jessa M Tunacao,Zhengping Zhuang,Danielle R Donahue,Vikram Chandrashekhar,John D Heiss

doi:10.1172/jci.insight.151222

Abstract

We recently described a transtentorial venous system (TTVS), which to our knowledge was previously unknown, connecting venous drainage throughout the brain in humans. Prior to this finding, it was believed that the embryologic tentorial plexus regresses, resulting in a largely avascular tentorium. Our finding contradicted this understanding and necessitated further investigation into the development of the TTVS. Herein, we sought to investigate mice as a model to study the development of this system. First, using vascular casting and ex vivo micro-CT, we demonstrated that this TTVS is conserved in adult mice. Next, using high-resolution MRI, we identified the primitive tentorial venous plexus in the murine embryo at day 14.5. We also found that, at this embryologic stage, the tentorial plexus drains the choroid plexus. Finally, using vascular casting and micro-CT, we found that the TTVS is the dominant venous drainage in the early postnatal period (P8). Herein, we demonstrated that the TTVS is conserved between mice and humans, and we present a longitudinal study of its development. In addition, our findings establish mice as a translational model for further study of this system and its relationship to intracranial physiology.

Highlights

We previously identified a consistent trans-tentorial venous system (TTVS) in humans that connects venous drainage throughout the brain and proposed their relationship to neurosurgical outcomes, including post-operative remote cerebellar infarct [1,2]
We found that the murine TTVS connects distant regions of the brain and has three main medial, intermediate, and lateral veins with plexiform anastomoses
We identified the murine homologue to the TTVS that we previously characterized in healthy adult humans via high resolution, contrast-enhanced computed tomography (CT)

Summary

Introduction

We previously identified a consistent trans-tentorial venous system (TTVS) in humans that connects venous drainage throughout the brain and proposed their relationship to neurosurgical outcomes, including post-operative remote cerebellar infarct [1,2]. These often-fatal clinical outcomes highlight the need to understand the complete intracranial vascular network. Previous adult human cadaveric studies of the tentorium identified medial (MTS) and lateral (LTS) tentorial sinuses, which are outpouchings of the transverse sinuses into the margin of the tentorium that may receive parenchymal bridging veins [6,7,8] These sinuses do not traverse the tentorium to connect distant regions of the brain. Our recent discovery of the TTVS warrants reevaluation of our understanding of the development of the intracranial venous system

Methods

Results

Conclusion