Lamellar Sectional Anatomy For Endoscopic Sphenoidotomy

Objective:To provide anatomy data of the sphenoid sinus and some surrounding structures for endoscopic sphenoidotomy by using the continuous horizontal and coronal lamellar sectional anatomy image.Method:The digital freezing milling technique was used to obtain the continuous lamellar sectional image data as thin as 0.1mm of 15 cadaver heads (30 sides) in horizontal and 10 cadaver heads (20 sides) in coronal without organic lesion.The sphenoid sinus and some surrounding structures were observed and measured on typical and continuous sectional image,which concluded the type and septum of sphenoid sinus,the optical nerve and the internal carotid how related to the sphenoid sinus.And the maximal vertical and horizontal longitude of the sphenoid sinus aperture and the distance of the aperture of sphenoid sinus to the internal carotid and to the optic nerve canal were measured.Results:l.The sectional image of 25 cadaver heads(both the horizontal and the coronal sectional image):Only 16.0% of septum located in the median sagittal section,8.0% of septum was absent.2.The horizontal sectional image of 15 cadaver heads (30 sides):66.7% of sphenoid sinus was sellae type,30.0% of sphenoid sinus was pre-sellar type,3.3% of sphenoid sinus was turbinate type.46.7% of optical nerve canal and 70% of internal carotid bulge on the area of lateral sphenoid sinus.The maximal vertical longitude of sphenoid sinus aperture was (3.41±0.56) mm and the maximal horizontal longitude was (2.24±0.35)mm.The distance of the aperture of sphenoid sinus to the internal carotid was (19.36±2.26)mm,the distance of the aperture to the optic nerve canal was (8.83±1.42)mm.3.The coronal sectional image of 10 cadaver heads (20 sides):75% of sphenoid sinus was sellae type,20% of sphenoid sinus was pre-sellar type,5% of sphenoid sinus was turbinate type.60% of optical nerve canal and 75% of internal carotid bulge on the area of lateral sphenoid sinus.Conclusion:The continuous horizontal and coronal lamellar sectional image obtained from digital freezing milling technique offered a better understanding of the sphenoid sinus and some surrounding structures and provided sectional anatomy data for the sphenoidotomy.