The Supraorbital Keyhole Craniotomy Approach to the Olfactory Tract: A Radiographic Study

Objectives: The goal of this study was to determine the best approach to the olfactory tract for implantation of an olfactory electrical stimulator to treat anosmia. Setting: Tertiary Academic Medical Center Methods: In this retrospective cohort study (n=50), CT scans from VCU Medical Center (July–October 2025) were reconstructed in three dimensions using syngo.via (Siemens Healthcare). Five standardized points corresponding to the supraorbital keyhole craniotomy (SOKC) footprint were plotted on the exterior skull: the supraorbital notch (1), 2 cm superior to the supraorbital notch (2), superior temporal line by the orbital rim (3), 2 cm superior to the third point (4), and the centroid of points 1-4 (5). Trajectories were drawn bilaterally from each point to the anterior (posterior crista galli) and posterior (anterior edge pituitary fossa) olfactory tracts, yielding 20 per subject. Each was evaluated for bony and sinonasal obstruction. Results: All subjects had at least one unobstructed trajectory. A path from 2 cm above the superior temporal line at the orbital rim to the posterior tract was clear in 98% and is the preferred surgical vector. Posterior trajectories were more often unobstructed than anterior trajectories (70% vs. 48%, p<0.0001). Rates of obstruction did not differ by age, sex, or BMI. Orbital bone was the most frequent obstruction. The average olfactory tract length was 28 mm bilaterally. Conclusion: The SOKC may be the preferred surgical approach for an olfactory implant. All patients had at least one route with an unobstructed view of either the anterior or posterior olfactory tract.