Anatomic comparison of trans-condyle versus trans-jugular process route in the far lateral approach by virtual reality technique

Abstract

Objective To discuss the impact of trans-condyle and trans-jugular process routes in the far lateral approach upon the exposure of realated anatomic structures based on virtual reality anatomic model. Methods CT and MR scans were performed to fifteen adult cadaver heads, and then, image data was input into Vitrea Fx 3.0 virtual reality system to establish three-dimensional anatomy model of jugular foramen region. Anterior edge of jugular tubercle in posterior cranial fossa was selected as landmark point to outline cylinder with diameter 1 cm simulating trans-condyle and trans-jugular process routes in far lateral minimally invasive approach. Anatomic exposures and the volume were observed and measured. Statistical comparison was launched by paired t test. Results Anatomic structures of osseous structures, nerves and vessels in the trans-condyle and trans-jugular process routes were displayed well. Brainstem, cerebellar, vertebral artery and posterior inferior cerebellar artery did not show in route. Trans-condyle route involved partial vagus nerve and accessory nerve. Trans-jugular process route involved partial internal jugular vein and jugular bulb. Comparison did not show statistically significant differences for the volumes of two routes [(3236.20±228.01) mm3 vs (3306.00±248.23) mm3] and hypoglossal nerve involved(all P values>0.05). The volumes of osseous structures and anterior inferior cerebellar artery involved in trans-condyle route were more than those in trans-jugular process route with statistically significant differences. The volume of vein in trans-jugular process route was more than that in trans-condyle route with statistically significant difference(t=7.324, 56.526, 140.580, all P values<0.01). Conclusions The routes from two directions in the far lateral approach can expose hypoglossal nerve effectively, of which trans-condyle route is prone to expose anterior inferior cerebellar artery. Trans-jugular process route can bypass the lower cranial nerve but with the risk of vein injury. Key words: Neurosurgical procedures; Cranial fossa, posterior; Neuronavigation; Models, anatomic; Minimal invasive