Department of Otolaryngology-Head and Neck Surgery, Mayo Clinic, Rochester, MN 55905, USA.
Department of Neurosurgery, Mayo Clinic, Rochester, MN, USA.
Am J Otolaryngol. 2022 Mar-Apr;43(2):103304. doi: 10.1016/j.amjoto.2021.103304. Epub 2021 Dec 3.
There is a void in the literature describing reliable surgical landmarks that aid in the dissection of the facial recess in the absence of skeletonizing the mastoid segment of the facial nerve. The posterior ligament of the incus is a readily distinguishable "white dot" along the incus buttress that has been used to guide dissection in a safe and efficient manner. The goal of our study is to describe a surgical approach that utilizes this surgical landmark to drill the facial recess and to take anatomical measurements demonstrating the safety and reliability of this approach.
After cortical mastoidectomies were performed in 10 cadaveric temporal bones, the white dot was identified at the junction of short process of the incus and the incus buttress. Using the white dot for anatomical reference, a 2 mm diamond drill bit was used to open the facial recess without first identifying the facial nerve or chorda tympani nerve. After photographs were taken, the facial and chorda tympani nerves were definitively identified and skeletonized to delineate the confines of the facial recess. Photographs were once again acquired in a consistent manner for comparison. Finally, calibrated anatomic measurements were acquired from the 10 distinct image sets.
The facial recess was successfully drilled in 10 temporal bones using the posterior ligament as a surgical landmark without injury to the chorda tympani or facial nerve. The median angle taken from the axis of the short process of the incus to the facial nerve - chorda tympani junction was 139.2° (IQR 136.8-141). At the widest point in the facial recess, median distances anterior and posterior to an imaginary line connecting the white dot to the facial nerve - chorda tympani junction were 1.6 mm (IQR 1.5-1.7) and 1.6 mm (IQR 1.6-1.7; p = 0.57), indicating at this point, the white dot reference reliably bisects the facial recess width. Similarly, at the level of the round window niche, median anterior and posterior distances from an imaginary line connecting the white dot to the facial nerve - chorda tympani junction were 1.1 mm (IQR 1.1-1.3) and 1.3 mm (IQR 1.1-1.7; p = 0.07), respectively, once again demonstrating the white dot reliably bisecting the facial recess.
The white dot, representing the posterior ligament of the incus, is a reliable surgical landmark that aids in safe and efficient drilling of the facial recess without first skeletonizing the facial nerve.
在不解剖面神经乳突段的情况下，描述有助于解剖面神经隐窝的可靠手术标志的文献中存在空白。锤骨后韧带是沿锤骨支撑突的一个可识别的“白点”，可用于安全有效地引导解剖。我们的研究目的是描述一种利用该手术标志来钻面隐窝的手术方法，并进行解剖测量，以证明该方法的安全性和可靠性。
在 10 具尸体颞骨上完成皮质乳突切除术之后，在锤骨短突和锤骨支撑突的交界处识别白点。使用白点作为解剖参考，使用 2mm 金刚石钻头打开面隐窝，而不首先识别面神经或鼓索神经。拍照后，明确识别面神经和鼓索神经并进行解剖以描绘面隐窝的范围。以一致的方式再次获取照片进行比较。最后，从 10 个不同的图像集中获取校准的解剖测量值。
在 10 个颞骨中，使用后韧带作为手术标志成功钻出面隐窝，而鼓索神经和面神经未受伤。从锤骨短突轴到面神经-鼓索神经结合处的中间角度为 139.2°（IQR 136.8-141）。在面隐窝最宽处，想象一条连接白点和面神经-鼓索神经结合处的线前后的中间距离为 1.6mm（IQR 1.5-1.7）和 1.6mm（IQR 1.6-1.7；p=0.57），表明在这一点上，白点参考可靠地平分面隐窝宽度。同样，在圆窗龛水平，从想象一条连接白点和面神经-鼓索神经结合处的线前后的中间距离为 1.1mm（IQR 1.1-1.3）和 1.3mm（IQR 1.1-1.7；p=0.07），再次表明白点可靠地平分面隐窝。
白点代表锤骨后韧带，是一种可靠的手术标志，可在不首先解剖面神经的情况下安全有效地钻面隐窝。
