Colasanti Roberto, Tailor Al-Rahim A, Lamki Tariq, Zhang Jun, Ammirati Mario
*Dardinger Microneurosurgical Skull Base Laboratory, Department of Neurological Surgery and §Department of Radiology and Wright Center of Innovation in Biomedical Imaging, Wexner Medical Center, The Ohio State University, Columbus, Ohio; ‡Department of Neurosurgery, Umberto I General Hospital, Università Politecnica delle Marche, Ancona, Italy.
Neurosurgery. 2015 Jun;11 Suppl 2:329-36; discussion 336-7. doi: 10.1227/NEU.0000000000000749.
Recent reports have validated the use of retrosigmoid approach extensions to deal with petroclival lesions.
To describe the topographic retrosigmoid anatomy of the intrapetrous internal carotid artery (IICA), providing guidelines for maximizing the petroclival region exposure via this route.
The IICA was exposed bilaterally in 6 specimens via a retrosigmoid approach in the semisitting position. Its topographic relationship with pertinent posterolateral cranial base landmarks was quantified with neuronavigation.
Safe exposure of the IICA and the surrounding inframeatal/petroclival regions was accomplished in all specimens. On average, the IICA genu was 15.08 mm anterolateral to the XI nerve in the jugular foramen, 16.18 mm anteroinferolateral to the endolymphatic sac, and 10.63 mm anteroinferolateral to the internal acoustic meatus. On average, the IICA horizontal segment was 9.92 mm inferolateral to the Meckel cave, and its midpoint was 19.96 mm anterolateral to the XI nerve in the jugular foramen. The mean distance from the IICA genu to the cochlea was 1.96 mm. The genu and the midpoint of the horizontal segment of the IICA were exposed at a depth of approximately 14.50 mm from the posterior pyramidal wall with the use of different drilling angles (49.74° vs 39.54°, respectively).
Knowledge of the IICA general relationship with these landmarks (combined with a careful assessment of the preoperative imaging and with the use of intraoperative navigation and micro-Doppler) may help to enhance the inframeatal/petroclival region exposure via a retrosigmoid route, maximizing safe inframeatal and suprameatal petrous bone removal while minimizing neurovascular complications.
近期报告证实了乙状窦后入路扩展用于处理岩斜区病变的有效性。
描述岩骨内颈内动脉（IICA）的乙状窦后入路局部解剖结构，为通过该入路最大化暴露岩斜区提供指导。
在6例标本上，采用半坐位乙状窦后入路双侧暴露IICA。利用神经导航系统对其与相关颅后外侧基底标志的局部关系进行量化。
所有标本均实现了IICA及其周围内听道/岩斜区的安全暴露。平均而言，IICA膝部位于颈静脉孔内Ⅺ神经前外侧15.08 mm、内淋巴囊前下外侧16.18 mm、内耳道前下外侧10.63 mm处。平均而言，IICA水平段位于半月神经节下方9.92 mm，其中点位于颈静脉孔内Ⅺ神经前外侧19.96 mm处。IICA膝部至耳蜗的平均距离为1.96 mm。采用不同的磨除角度（分别为49.74°和39.54°）时，IICA膝部和水平段中点距后锥壁的深度约为14.50 mm。
了解IICA与这些标志的一般关系（结合术前影像学的仔细评估以及术中导航和微型多普勒的使用）可能有助于通过乙状窦后入路增强内听道/岩斜区的暴露，在最大程度安全磨除内听道和内耳道上岩骨的同时，将神经血管并发症降至最低。
