Topographic anatomy of two-piece orbitozygomatic, modified orbitozygomatic and transzygomatic approaches: A comparative analysis of neurosurgical options

Aim to measure and compare the vertical and horizontal angles of attack on different intracranial surgical targets provided by the transzygomatic, modified orbitozygomatic and classic two-piece orbitozygomatic approaches, to determine the most optimal approaches to different surgical targets. Material and methods. The study was conducted on 8 sides of en bloc specimens of human head and neck. The marking was performed with BrainLAB Kolibri navigational station (Germany) to highlight the surgical landmarks and measure the angles. The dissection was started macroscopically with standard instruments and photographic fixation of every stage of the approach. The craniotomy was performed with Stryker high speed drill (USA). After that, the microscopic stage was carried out with the ZEISS OPMI Vario/S88 surgical microscope (Germany). On each side, the following steps were completed: soft tissues dissection, cutting the zygomatic arch, fronto-temporal craniotomy, orbitozygomatic osteotomy, opening of the dura mater and dissection of structures of the cranial base, measurement of angles of attack with their apex located on skull base structures Results. The angles of attack on different intracranial surgical targets were measured and compared for two-piece orbitozygomatic, modified orbitozygomatic and transzygomatic approaches. Conclusion. The two-piece orbitozygomatic craniotomy is the most universal and optimal to approach the basilar artery bifurcation and lesions located in both anterior and middle cranial fossae. However, to minimize the surgical trauma and the risks of complications when exposing exclusively anterior cranial fossa, the modified orbitozygomatic approach is more adequate. When the lesion is small and located exclusively in middle cranial fossa, performing the transzygomatic approach is recommended.