Division of Neurological Surgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, Arizona, USA.
Neurosurgery. 2010 Jun;66(6 Suppl Operative):191-8; discussion 198. doi: 10.1227/01.NEU.0000369704.49958.5B.
The rationale for choosing between the condylar fossa and transcondylar variations of the far-lateral approach requires understanding of the relationships between the occipital condyle, jugular tubercle, and hypoglossal canal.
We examined the anatomic relationship of these 3 structures and analyzed the effect that changes in these relationships have on the surgical exposure and angle of attack for these 2 approaches.
Anatomic measurements of 5 cadaveric heads from 3-dimensional computed tomographic scans were compared with direct measurements of the same specimens. The condylar fossa and transcondylar approach were performed sequentially in 8 of 10 sides. Surgical exposure and angle of attack were measured after each exposure.
The jugular tubercle (JT) angle (JTA) measures the angle formed by reference points on the condyle, hypoglossal canal, and JT. When the JT and occipital condyle are not prominent (JTA > 180 degrees ), the transcondylar approach does not significantly increase petroclival or brainstem exposure compared with the condylar fossa approach; however, it does significantly increase the angle of attack to the junction of the posterior inferior cerebellar and vertebral arteries and the surgical angle for the medial part of the JT (P < .05).
The condylar fossa and transcondylar approaches provide similar exposures of the petroclivus and brainstem when the JT and occipital condyle are not prominent (JTA > 180 degrees on 3-dimensional computed tomographic). However, for lesions below the hypoglossal canal, the transcondylar approach is preferred because it significantly increases the angle of attack.
选择髁状突窝入路和远外侧经髁突入路的基本原理需要理解枕髁、颈静脉结节和舌下神经管之间的关系。
我们研究了这 3 个结构的解剖关系，并分析了这些关系的变化对这两种入路的手术暴露和攻角的影响。
通过比较 3 名尸体头的 3 维 CT 扫描的解剖测量值和对相同标本的直接测量值，对 5 个尸头的解剖关系进行了分析。在 10 侧中，有 8 侧连续进行髁状突窝入路和经髁突入路。在每次暴露后测量手术暴露度和攻角。
颈静脉结节角（JTA）测量的是髁状突、舌下神经管和颈静脉结节上的参考点形成的角度。当颈静脉结节和枕髁不突出（JTA>180 度）时，与髁状突窝入路相比，经髁突入路并不能显著增加岩斜区和脑干的暴露；但是，它确实显著增加了到后下小脑动脉和椎动脉的交界处以及颈静脉结节内侧部分的手术角度（P<0.05）。
当颈静脉结节和枕髁不突出（3 维 CT 上 JTA>180 度）时，髁状突窝入路和经髁突入路可提供相似的岩斜区和脑干暴露。然而，对于舌下神经管以下的病变，经髁突入路更可取，因为它显著增加了攻角。
