幼儿人工耳蜗植入点定位的应用解剖学

目的 为幼儿人工耳蜗植入术提供解剖学依据.方法 取1～5周岁因故死亡儿童头颅14具,在28例标本上,模拟经乳突后鼓室入路手术.切除乳突,保留外耳道后壁,显露砧骨窝,去除面神经和鼓索神经之间的骨质进入后鼓室,在手术显微镜下(×6)观察并测量与耳蜗植入点相关的解剖学数据.结果 圆窗位于圆窗龛前缘上部.锥隆起、镫骨肌腱、砧镫关节、镫骨底板、圆窗龛、鼓岬、外侧半规管突等解剖标志清晰且恒定.镫骨后弓相当于鼓阶的前界.鼓阶位于前庭阶后下的位置.圆窗龛前缘中点到鼓阶下壁、鼓阶后壁、基底膜、锥隆起、外侧半规管突、镫骨底板下缘中点、匙突的距离分别为(1.49±0.42)mm、(0.90±0.31)mm、(1.49±0.41)mm、(3.28±0.55)mm、(7.41±0.9)mm、(3.09±0.53)mm、(4.83±0.65)mm.结论 幼儿人工耳蜗植入点应选择在圆窗龛前游离缘中点向前0.90～1.49mm、向下1.49mm以内的位置;在圆窗龛显示困难的病例,植入点应定位于距镫骨底板下缘中点下方约3mm处.

APPLIED ANATOMY OF THE ARTIFICIAL COCHLEAR IMPLANTATION IN YOUNG CHILDREN

Objective To provide anatomic data for operation of inserting the electron cochlear in young children. Methods Fourteen heads,28 sides specimens of young children of 1-to-5-year old were dissected,through posterior tympanum approach,via mastoidectomy,posterior tympanoto to enter posterior tympanum.The related anatomy structures of the location of the electron cochlear inserted into the proper sites were observed and measured under surgical microscope. Results The round window was seated in superior part of the round window niche.The pyramidal eminence,tendo musculi stapedius,incudostapedial joint,base of stapes,cochleariform process,round window niche and promontorium tympani were all visible from different directions.The posterior arch of stapes was situated in the prozone of scala.Scala was situated in the posteroinferior scala vestibuli.The distance from the middle point of the anterior border of the round window niche to the inferior wall was (149±0.42)mm,to the posterior wall of the Scala tympani (0.90±0.31)mm,to the basal tissue (149±0.41)mm,to the pyramidal eminence (328±0.55)mm,to the lateral semicircular canal (741±0.90)mm,to the inferior margin of the base of stapes (309±0.53)mm.Conclusion It is considered that the location of the insertion should be at the middle point of anterior border of the round window niche anterior from 0.90mm to 149