下鼓室的应用解剖

目的　探讨颈动脉管、颈静脉窝与下鼓室的变异关系 ,为此区域手术提供可靠的解剖学资料。方法　在XSQ～Ⅱ型手术显微镜下解剖观察了 2 0 0例颞骨标本的下鼓室 ,并用游标卡尺对有关结构进行了测量。结果　下鼓室纵径 0 2 8mm ,横径为 0 85mm ,深为 1 2 8mm。下鼓室底与颈静脉窝相毗邻者见 93 0 %。当颈静脉窝大而上隆时 ,窝顶与鼓室间以薄骨板分隔 ,骨板最薄时仅为 0 2 0mm。颈静脉窝顶突入鼓室腔者占 1 2 5 % ,窝顶有骨质缺损者见 4 0 %。鼓室底与颈动脉管关系随颈动脉位置变化而异 ,有 6 8 0 %的标本颈动脉管位于岬下缘前 1 / 3区 ,4 0 %的标本颈动脉管占据范围达岬下缘后 1 / 3区。结论　下鼓室与颈静脉窝及颈动脉管存在着多种变异关系 ,下鼓室手术及静脉窝区手术应避免损伤颈静脉球及颈内动脉等结构

Applied Anatomical Study on Hypotympanum

Objective To explore the variable relationship among carotid canal, jugular pit and hypotympanum to provide applied anatomic data for the operations of jugular pit and hypotympanum region. Methods Hypotympanum was dissected and observed in 200 cases of bone specimens under XSQ Ⅱ surgical microscope and was measured with slide gauger. Results The superoinferior diameter of hypotympanum was 0.28mm, the anteroposterior diameter was 0.85mm and the depth was 1.28mm. The bottom of hypotympanum was adjacent to jugular pit in 93.0% specimens. When jugular pit was big and eminentia, the summit of jugular pit was separated by thin bone lamella, and the thinnest of them was only 0.2mm. The summit of jugular pit protruded into tympanic cavity was 12.5% of specimens and lacked bone substantia was 4.0% of specimens. The relationship between the bottom of tympanic cavity and carotid canal varied with position changes of carotid canal which was located at the anterior 1/3 part of the interior promontory in 68.0% specimens, and at the posterior 1/3 part of the interior of promontory in 4.0% specimens. Conclusion There are diversified variation relationship among hypotympanum and jugular pit and carotid canal. The operative filed of jugular pit and hypotympanum should be confined to avoid damaging the jugular pit and internal carotid artery.