Ghorayeb B Y, Jahrsdoerfer R A
Department of Otolaryngology-Head and Neck Surgery, University of Texas Medical School, Houston 77030.
Otolaryngol Head Neck Surg. 1990 Jul;103(1):60-5. doi: 10.1177/019459989010300109.
Cholesterol granulomas of the petrous apex are drained through two major extralabyrinthine routes: one, along the posterosuperior chain of air cells, and two, along the anteroinferior chain. Procedures that use the posterosuperior chain approach the apex from the sinodural angle, the base of the zygomatic arch, the attic, or through the arch of the superior semicircular canal. Operations that use the anteroinferior chain reach the apex along the internal carotid canal (Ramadier's operation) or by a posterior infralabyrinthine approach between the descending facial nerve and jugular bulb. Inferior petrous apex cholesterol granulomas may be unreachable by any of these routes, and hence the subcochlear route is proposed as an alternative. The subcochlear approach starts in a triangle bounded superiorly by the cochlea, anteriorly by the internal carotid canal and posteriorly by the deep jugular vein. This operation requires lowering the inferior bony canal wall to the level of the "crutch." It provides access to an inferiorly situated cholesterol granuloma, yet preserves hearing. It allows enough room for the placement of a tube drain from the petrous apex to the mastoid. It is particularly useful when a high jugular bulb precludes the use of the posterior infralabyrinthine route.
其一，沿气房的后上链；其二，沿前下链。采用后上链的手术从窦硬膜角、颧弓根部、鼓室上隐窝或通过上半规管弓进入岩尖。采用前下链的手术沿颈内动脉管（拉马迪埃手术）或通过在下行面神经和颈静脉球之间的迷路后下途径到达岩尖。岩尖下部的胆固醇肉芽肿可能无法通过这些途径中的任何一条到达，因此提出经耳蜗下途径作为一种替代方法。经耳蜗下途径始于一个三角形区域，其上界为耳蜗，前界为颈内动脉管，后界为深颈静脉。该手术需要将下骨管壁降低到“支柱”水平。它可用于进入位于下方的胆固醇肉芽肿，同时保留听力。它为从岩尖到乳突放置引流管留出足够空间。当高位颈静脉球妨碍使用迷路后下途径时，它特别有用。
