The Microstructure Of The Brain Deep Vein Anatomy And Clinical Applications

Objective:To study the composition of the cerebral deep vein system and explore effects of the cerebral deep vein system and its anatomical variance on microsurgery for the lesions in the back of tentorial incisure space.Methods:The transoccipito- supratentorial and infratentorial supracerebellar approaches were simulated in 20(40 hemispheres) formalin fixed adult cadaveric brains in which the cerebral arteries and veins had been perfused respectively with red and blue latex.The tributaries of the Galen venous(GV) system,which interfered in entering the back of tentorial incisural space,were observed under an operating microscope.The composition of GV system and datums related to it were analyzed and measursed.At the same time,the fifteen formalin-fixed heads were applied to simulated the simulated the transcallsal—interforniceal approach under a microscope.The cerebral internal vein(CIV) and its related branches were dissected,measursed and studied too.Results:GV system was divided into six types according theirs composition,but CIV was five types.The angle between the straight sinus and the GV was(78±14.9)°,The outer diameters of GV was(5±1.0) mm,the length of its was(9.7±4.9) mm.The posterior outer diameters of CIV was(3.0±0.5) mm,anterior outer diameters was(1.95±0.29) mm,the length of its was(33.1±7.2) mm.The thick medial occipital veins,of which,the outer diameter was(2.0±0.4) mm,were identified in 9(22.5%,9/40) sides of the hemispheres.The thick precentral cerebellar veins,of which,the outer diameter was(2.0±0.2) mm,were also identified in 5(25%,5/20) brains,The defect of anterior or middle or posterior segments of the basal veins(BV) of Rosenthal was observed in some dissected specimens.The outer diameters of BV was(2.481±0.7097) mm,the length of its was(35.827±13.898) mm.he difference between the external diameter of the obviously variant spetum pellucidum vein and the anterior part of cerebral internal vein was not marked.the left and the right cerebral internal vein which run parallelly at the top of the third ventricle is not always in the same horizontal plane,but there existed the relationship which is up and down.The medial occipital veins and the basal vein of Rosenthal interfered in entering the region in the back of the tentorial incisural space when microsurgery through the transoccipito- supratentorial approach was performed,and the precentral cerebellar veins possibilly interfered in entering the region of the back of tentorial incisural space when microsurgery through the infratentorial supracerebellar approach was performed.Conclusion:Galen venous system,cerebral internal vein and their tributaries are highly variable anatomically.The anatomical variance of GVsystem,of CIVand their tributaries will have effects on microsurgery for the lesions in the brain possibly.