乙状窦后经内耳孔上入路扩大颅底显露的数量化研究

目的量化研究乙状窦后经内耳孔上入路所能扩大显露中颅窝、上斜坡的范围。材料为成人颅骨标本、尸头标本、新鲜头颅标本共28例,手术显微镜下放大8~12倍观察研究。方法经改良乙状窦后入路开颅,磨除内耳孔上结节和部分岩尖。采用实体和CT测量结合的方法测量内耳孔上结节、岩尖的切除范围。记录内耳孔上结节、岩尖切除前后中颅窝、上斜坡的显露面积和三叉神经的显露范围。结果内耳孔上结节中线-侧方、前-后方向骨性组织可以全部切除。将内听道的上壁轮廓化切除其上下径。岩尖的前-后、中线-侧方、上-下方向骨性组织均不能完全切除。中颅窝扩大显露范围为(144.6±13.9)mm2,上斜坡扩大显露(90.3±16.7)mm2。结论乙状窦后经内耳孔上入路可以将乙状窦后入路的手术野扩大显露到中颅窝的中线部、上斜坡侧方,并可显露Meckel′s腔内三叉神经。

A Quantitative Study on the Enlarged Exposure Field by the Retrosigmoid Suprameatal Approach

Objective To study the quantitative changes of the exposed field of the middle fossa and the superior clivus by the RSSMA.Materials were 28 human cranium;formalin fixed cadavers and fresh cadavers were studied and operation microscopes was used for 8～12 times.Methods Based on the retrosigmoid approach,the suprameatal terbucle(ST) and the petrosal apex(PA) was drilled.The CT and the manual measurements were used in determining the length of the ST and PA in three dimensions before and after the resection of them.The exposed field of the middle fossa and superior clivus and the length of the exposed trigeminal nerve were also measured.Results The middle-lateral,anterior-posterior part of the ST could be wholly resected.And in the superior-inferior direction,auditory canal could be skeletonized.The PA was partially resected.(144.6±13.9) mm2 of the middle fossa and(90.3±16.7) mm2 of the superior clivus were added to be exposed.Conclusion The median part of the middle fossa and the lateral part of the superior clivus and the trigeminal nerve in the Meckel's cave could be exposed by the RSSMA.