Search

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.

To perform an adequate orbitozygomatic craniotomy, it is very important that the bone cut which passes through the body of the zygoma reaches the inferior orbital fissure (IOF). To reach the IOF, two surface landmarks on the body of the zygoma are described: a point located directly superior to the malar eminence and the zygomaticofacial foramen. The article explores the reliability of these landmarks and three other alternative points to reach the IOF. Eighty-three adult skulls were used in this study. The IOF dimensions and the relationship with the malar eminence, the point superior to the malar eminence, the zygomaticofacial foramen, and 3 alternative points (E, C, F) were analyzed. The malar eminence was unacceptable for use as a guide to the IOF. The point superior to the malar eminence was also unacceptable as a guide as only 9.4% and 10.9% were in the projection of the IOF on the right and left, respectively. 59.7% of the total zygomaticofacial foramina fell in the IOF projection. The point F fell in the projection of the IOF in 98.8% and 100.0% on the right and left, respectively. The use of the malar eminence as a guide to reach the IOF is unreliable in one third of cases as it is not easily identified intraoperatively in these cases. The zygomaticofacial foramen cannot be considered a reliable surgical landmark to reach the IOF. The authors recommend using a novel landmark which may be identified as a midpoint between intersections of the anterior and posterior margins of the zygomatic frontal process on a line extending from the inferior margin of the zygomatic arc. This point is reliable in 98.8-100% of cases.