Neurosurgial Microanatomy Study Of Trans Callosal-Choroid Fissure Approach To The Third Ventricle

Objective To supply microanatomic data for the application of the transcallosal-choriod fissure approach,in order to help surgeons to identify and protect vital vascular and nervous structuresduring operation.Methods Ten adult cadaveric head specimens were dissected by using microsurgical an atomic skill,simulating the procedures of the transcallosal—choriod fissure approach.Observation were performed on related an atomic structures,measurement and photographers were taken, too.Results Point of coronal suture and sagittal(PoCS)was identified easy in all specimen,located superior glabella 125.9±6.76mm.Within the range of 1cm-4cm in front of the PoCS,85%has no frontal vein.The bridge veins were rare in this region.The precentral sulcus was easier indentified in the cerebral medial surface;The distance from ahead 2cm of PoCS to corpus callosum was 39.33±3.05mm;Pericallosal artery parallel on the corpus callosupper surface generally in the operative view field,Corpus callosum is bright white and bloodless.A small artery was found in a groove located between the medial longitudinal striate in the middle of the corpus callosum:Using two points on the cortical surface as references that were located 5 and 7cm an terior to the central sulcus respectively,mean values of relative measurements were obtained as follows:(1)the distance between A5 / A7 and the cingulate sulcus was 29.26mm and 30.43mm:(2)the distance between the lower margin of the corpus callosum and the fornix was 7.53mm and 9.88mm:(3)the hei ght of the corpus callosum was 7.18mm and 7.78ram:(4)the distance between the anterior commissure and the foramen of Monro was 5.04mm.Conclusions The corridor of the transcallosal- choriod fissure apporoach is bounded between the lines of A5—callosum and A7-callosum, the small artery in a groove located be tween the medial longitudinal striae should be used to landmark of incision into the corpus callosum: The quantitative inforation obtained in this study permitted preservation of important anatomic structures in operation,such as the motor strip,genu of the corpus callosum,fomical commissure and an terior commissure.