Cadaveric analysis of transcranial versus endoscopic transorbital petrosectomy: comparison of surgical maneuverability and brainstem exposure

Introduction While accessing the posterior fossa, anterior transpetrosal approach (ATPA) and endoscopic transorbital (ETOA) use same bony landmarks during petrous apex drilling. However, owing to their contrasting surgical axes, they are expected show differences in view, maneuverability, clinical implications. This study aimed investigate feasibility of ETOA brainstem compare view maneuverability each approach. Methods ATPA were performed four human cadaveric heads (eight sides procedure). The angle attack (AOA) depth measured at target interest (root exit zone [REZ] cranial nerve [CN] V, VI, VII). When measuring area exposure, was divided into two areas (anterior lateral brainstem) based on longitudinal line crossing entry trigeminal root, measured. Results showed significantly greater value REZ both vertical (31.8 ± 6.7° vs. 14.3 5.3°, p=0.006) horizontal AOA (48.5 2.9° 15.0 5.2°, p<0.001) than ETOA. facial also (vertical, 27.5 3.9° 8.3 3.3°, p<0.001; horizontal, 33.8 2.2° 11.8 2.9°, p<0.001). presented shorter (CN 5.8 0.5 cm 9.0 0.8, CN VII, 6.3 9.5 1.0, p=0.001) mean exposure did not differ between approaches. better (240.7 9.6 mm 2 171.7 , p<0.001), while demonstrated (174.2 29.1 231.1 13.6 p=0.022). Conclusions could be a valid option, selected cases, that provides direct ventral route brainstem. Compared with ATPA, less longer depth; however, it comparable