Assessing the potential of transorbital and supraorbital approaches for stereotactic surgery: an anatomical feasibility study.

Aim: The Transorbital and supraorbital minimally invasive approaches have been defined to reach intraorbital structures, adjacent sinuses, skull base, and other intracranial targets in this region. These approaches reduce the possible cosmetic and brain retraction-related morbidities caused by traditional transcranial approaches. Although these pathways are being studied endoscopically, a stereotactic approach has not been defined. The Kocher`s point and its surroundings, which are traditional entry points used in stereotactic surgery create compelling trajectories, carry a potentially higher complication risk for subventricular psychosurgical and hypothalamic targets. Herein, we aimed to evaluate the supraorbital and transorbital approaches as alternative entry sites and trajectories targeting the nucleus accumbens (NAc), subcallosal cingulate gyrus (SCG), and lateral hypothalamic area (LHA), in cadavers and surgical planning station.

Material and methods: The three-dimensional relationship of the identified trajectories within the anterior and middle cranial fossae as well as the stereotactically targeted NAc, SCG, and LHA, were demonstrated through dissection studies conducted in cadavers. To validate the accuracy of the measurements from the cadaver, trajectory planning was replicated using radiological imaging of patients without a space-occupying lesion who underwent gamma knife surgery. These measurements were compared with those from cadavers.

Results: The transorbital and supraorbital trajectories did not pass through the lateral ventricles and they can be used for subventricular targets. Additionally, the NAc and LHA can be targeted simultaneously. These trajectories pass along a broader anatomical area within the NAc due to the anatomical orientation of the nucleus.

Conclusion: These findings suggest that these entry points may offer new opportunities for stimulating different targets in the prefrontal cortex and may serve as an approach for future clinical use.