内镜下迷路后入路小脑脑桥角及内耳门区手术的实验解剖

Anatomic study of the cerebellopontine and internal acoustic canal surgery aided by endoscope with retrolabyrinthine approach

目的测量比较内耳门后唇至乙状窦前、后缘的距离;迷路后间隙与乙状窦距外耳道后壁距离的相关性,为经迷路后入路内镜下小脑脑桥角区及内耳道微创手术提供解剖学依据。方法 10%甲醛固定的成人头颅标本(正常完整颅底)15例(30侧),性别不限,乳突轮廓化,迷路骨骼化,乙状窦全程解剖。①测量内耳门后唇至乙状窦前、后缘的距离;②测量乙状窦前缘至后半规管弧顶及其到骨性外耳道后壁之间距离。经统计学处理及分析。结果①内耳门后唇至乙状窦前、后缘之间的距离分别为(26.74±1.26)mm和(32.46±2.24)mm;②乙状窦前缘与骨性外耳道后壁及与后半规管弧顶之间距离的平均值分别为(15.65±1.26)mm和(10.83±0.85)mm,两者之间有明显相关性(r=0.672,P<0.01)。结论①迷路后入路小脑脑桥角手术较乙状窦后入路的路径更短且直接;②通过测量乙状窦与外耳道后壁之间的距离可用于评估迷路后间隙的大小,从而对小脑脑桥角手术入路提供参考。

OBJECTIVE To study the relationship between retrolabyrinthine space and the distance from sigmoid sinus to posterior wall of external acoustic canal for providing related information on cerebellopontine angel and internal acoustic surgery aided by endoscope via retrolabyrinthine approach.METHODS Fifteen adult cadaver heads（30 sides） fixed with formalin were studied.All the cadaver heads were undergone radical mastoidectomy,labyrinthine sketelization,and sigmoid sinus anatomized.①The distances from posterior margin of internal acoustic pore to the anterior edge of sigmoid sinus and to the posterior edge of sigmoid sinus were measured.②The distances from anterior edge of sigmoid sinus to the posterior wall of external acoustic canal and to the posterior semicircular canal were also measured.RESULTS ①The distances from posterior margin of internal acoustic pore to the anterior edge of sigmoid sinus and to the posterior edge of sigmoid sinus were（26.74±1.26）mm and（32.46±2.24）mm respectively.②The distances from anterior edge of sigmoid sinus to the posterior wall of external acoustic canal and to the posterior semicircular canal were（15.65±1.26）mm and（10.83±0.85）mm respectively and they had significant correlation（r=0.672,P0.01）.CONCLUSION ①The distance is shorter to internal acoustic pore in retrolabyrinthine approach than that in retrosigmoid approach if made sigmoid sinus as borderline.②It can be estimated the retrolabyrinthine space indirectly by measuring the distance from the sigmoid sinus to the posterior wall of external acoustic canal,and that can provide more information for cerebellopontine angel minimally invasive surgery aided by endoscope via retrolabyrinthine approach.