Nguy Peter L, Saidha Sheela, Jay Ann, Jeffrey Kim H, Hoa Michael
Department of Otolaryngology-Head and Neck Surgery, Georgetown University Medical Center, Washington DC, USA.
Department of Otolaryngology, University of Rochester Medical Center, Rochester, NY, USA.
World J Otorhinolaryngol Head Neck Surg. 2020 Jun 20;7(1):9-16. doi: 10.1016/j.wjorl.2018.12.003. eCollection 2021 Jan.
To determine anatomic relationships and variation of the round window membrane to bony surgical landmarks on computed tomography.
Retrospective imaging review.
100 temporal bone images were evaluated. Direct measurements were obtained for membrane position. Vector distances and angulation from umbo and bony annulus were calculated from image viewer software coordinates.
The angle of round window membrane at junction with cochlear basal turn was (42.1 ± 8.6)°. The membrane's position relative to plane of the facial nerve through facial recess was (14.7 ± 5.2)° posterior from a reference line drawn through facial recess to carotid canal. Regarding transtympanic drug delivery, the round window membrane was directed 4.1 mm superiorly from the inferior annulus and 5.4 mm anteriorly from the posterior annulus. The round window membrane on average was angled superiorly from the inferior annulus (77.1 ± 27.9)° and slightly anteriorly from the posterior annulus (19.1 ± 11.1°). The mean distance of round window membrane from umbo was 4 mm and posteriorly rotated 30° clockwise from a perpendicular drawn from umbo to inferior annulus towards posterior annulus. Together, these measurements approximate the round window membrane in the tympanic membrane's posteroinferior quadrant.
These radiologic measurements demonstrate normal variations seen in round window anatomy relative to facial recess approach and bony tympanic annulus, providing a baseline to assess round window insertion for cochlear implantation and outlines anatomic factors affecting transtympanic drug delivery.
通过计算机断层扫描确定圆窗膜与骨性手术标志的解剖关系及变异情况。
回顾性影像研究。
评估100张颞骨图像。直接测量膜的位置。根据图像观察软件坐标计算从鼓脐和骨性环带到圆窗膜的矢量距离和角度。
圆窗膜与蜗底转交界处的角度为（42.1±8.6）°。圆窗膜相对于通过面神经隐窝的面神经平面的位置，从经面神经隐窝至颈动脉管的参考线向后为（14.7±5.2）°。关于经鼓室给药，圆窗膜从下鼓环向上4.1mm，从后鼓环向前5.4mm。圆窗膜平均从下鼓环向上倾斜（77.1±27.9）°，从后鼓环向前轻微倾斜（19.1±11.1°）。圆窗膜距鼓脐的平均距离为4mm，从鼓脐垂直向下至下鼓环向后方顺时针旋转30°至后鼓环。这些测量结果共同勾勒出鼓膜后下象限的圆窗膜情况。
这些影像学测量结果显示了圆窗解剖结构相对于面神经隐窝入路和骨性鼓环的正常变异，为评估人工耳蜗植入时圆窗的植入情况提供了基线，并概述了影响经鼓室给药的解剖学因素。
