Seoane E, Rhoton A L
Department of Neurological Surgery, University of Florida, Gainesville 32610-0265, USA.
Neurosurgery. 1999 Mar;44(3):553-60. doi: 10.1097/00006123-199903000-00065.
This study was conducted to determine whether removing the bony prominence located above the porus of the internal acoustic meatus, called the suprameatal tubercle, and surrounding bone using the retrosigmoid approach would aid in the exposure of tumors that are located predominantly in the cerebellopontine angle but that also extend into the middle cranial fossa in the region of Meckel's cave and thus avoid the need for a supratentorial craniotomy.
Thirty cerebellopontine angles from 15 cadaveric heads examined using 3 to 40x magnification provided the material for this study. A retrosigmoid craniotomy was completed and the exposure obtained before and after removing the suprameatal tubercle, and the surrounding bone was examined. In some cases, Meckel's cave and the tentorium lateral to the porus of Meckel's cave was opened to aid in the exposure.
Removing the suprameatal tubercle and surrounding bone increased the exposure an average of 10.3 mm (range, 8.0-13.0 mm) forward of the exposure, which could be obtained without suprameatal drilling. The extent of bone removal was limited on the lateral side by the posterior and superior semicircular canals and their common crus.
The suprameatal extension of the retrosigmoid approach will permit removal of some tumors that are located mainly in the posterior fossa but that extend into the middle fossa in the region of Meckel's cave. The exposure can be increased by opening the superior petrosal sinus as it crosses in the upper margin of the porus of Meckel's cave and by opening the tentorium lateral to Meckel's cave.
本研究旨在确定采用乙状窦后入路切除位于内耳道孔上方的骨性隆起（即颞骨岩部上结节）及其周围骨质，是否有助于暴露主要位于桥小脑角但也延伸至Meckel腔所在的中颅窝区域的肿瘤，从而避免进行幕上开颅手术。
使用15个尸头的30个桥小脑角，放大3至40倍进行检查，为该研究提供材料。完成乙状窦后开颅手术，在切除颞骨岩部上结节及其周围骨质前后检查暴露情况。在某些情况下，打开Meckel腔及Meckel腔孔外侧的小脑幕以辅助暴露。
切除颞骨岩部上结节及其周围骨质后，暴露范围比未进行颞骨岩部钻孔时平均向前增加了10.3毫米（范围为8.0 - 13.0毫米）。骨质切除范围在外侧受后半规管、上半规管及其总脚的限制。
乙状窦后入路的颞骨岩部延伸部分可用于切除一些主要位于后颅窝但延伸至Meckel腔所在中颅窝区域的肿瘤。通过打开岩上窦在Meckel腔孔上缘的交叉处以及打开Meckel腔外侧的小脑幕，可增加暴露范围。
