Wu Chen-yi, Lan Qing
Department of Neurosurgery, Second Affiliated Hospital, Suzhou University, Suzhou, Jiangsu 215004, China.
Chin Med J (Engl). 2008 Apr 20;121(8):740-4.
Despite the presigmoid transpetrosal approach has been used by different researchers in various ways, the surgical injury rate remains high. Applying a minimally invasive keyhole idea, we devised a presigmoid transpetrosal keyhole approach (PTKA), classified and quantitatively assessed their approach to the petroclival area on a cadaver model by using a neuronavigation system.
The presigmoid transpetrosal keyhole approach was divided into four increasingly morbidity-producing steps: retrolabyrinthine, partial labyrinthectomy with petrous apicectomy, translabyrinthine and transcochlear keyhole approaches. Six latex-injected cadaveric heads (twelve sides) underwent dissection in which a neuronavigation system was used. An area of exposure 10 cm superficial to a central target (working area) was calculated. The area of clival exposure with each subsequent dissection was also calculated.
The retrolabyrinthine keyhole approach (RLK) spares hearing and facial function in theory but provides for only a small window of upper clival exposure. The view afforded by partial labyrinthectomy with petrous apicectomy keyhole approach (PLPAK) provides for up to four times this exposure. The translabyrinthine keyhole approach (TLK) and transcochlear keyhole approach (TCK), although producing more morbidity, add little in terms of a larger petroclival window. However, with each step, the surgical freedom for manipulation of instruments increases.
The presigmoid transpetrosal keyhole approach to the petroclival area is feasible and useful. The RLK has relatively limited utility. For lesions without bone invasion, the PLPAK provides a much more versatile exposure with an excellent chance of hearing and facial nerve preservation. The TLK provides for greater versatility in treating lesions but clival exposure is not greatly enhanced. The TCK adds little in terms of intradural exposure but should be reserved for cases in which access to the petrous carotid artery is necessary.
尽管乙状窦前经岩骨入路已被不同研究者以多种方式应用，但其手术损伤率仍然很高。应用微创锁孔理念，我们设计了乙状窦前经岩骨锁孔入路（PTKA），并通过神经导航系统在尸体模型上对其进入岩斜区的方式进行分类和定量评估。
乙状窦前经岩骨锁孔入路分为四个损伤程度逐渐增加的步骤：迷路后、部分迷路切除联合岩尖切除、经迷路和经耳蜗锁孔入路。对6个注入乳胶的尸头（12侧）进行解剖，术中使用神经导航系统。计算距中央靶点（工作区）10 cm浅表处的暴露面积。同时计算每次后续解剖时斜坡的暴露面积。
迷路后锁孔入路（RLK）理论上可保留听力和面部功能，但仅能提供较小的上斜坡暴露窗口。部分迷路切除联合岩尖切除锁孔入路（PLPAK）提供的视野可达此暴露面积的四倍。经迷路锁孔入路（TLK）和经耳蜗锁孔入路（TCK）虽然损伤更大，但在扩大岩斜窗口方面增加不多。然而，每一步操作中，器械操作的手术自由度都有所增加。
乙状窦前经岩骨锁孔入路进入岩斜区是可行且有用的。RLK的实用性相对有限。对于无骨质侵犯的病变，PLPAK能提供更广泛的暴露，且保留听力和面神经的机会极佳。TLK在治疗病变时具有更大的灵活性，但斜坡暴露并未显著增加。TCK在硬膜内暴露方面增加不多，但应保留用于需要暴露岩部颈动脉的病例。
