The Supraorbital Keyhole Approach.

Aim: The major aim of the present anatomical study was to demonstrate the anatomical structures that can be visualized using the supraorbital keyhole approach, both endoscopically and microscopically, from an eyebrow incision to intracranial structures. Furthermore, it defines an optimal craniotomy for surgery.

Methods: Fine dissection was performed on each side of 5 formalin-fixed adult cadavers according to the surgical procedures of the supraorbital keyhole approach, and each step was documented both endoscopically and microscopically. Furthermore, the distance between the superior temporal line and the supraorbital notch/foramen was measured from the 10 total sides of the 5 cadavers and from the 118 sides of the 59 autopsies.

Results: Tumors and aneurysms of the anterior cranial fossa can be visualized during the supraorbital keyhole approach. The average distance between the superior temporal line and the supraorbital notch/foramen was measured. The distance obtained from the autopsies on the 25 females was 31.56 ± 4.03  mm on the right side and 31.04 ± 5.40  mm on the left side. The average distance obtained from the autopsies on the 34 males was 34.00 ± 4.59  mm on the right side and 33.59 ± 5.41  mm on the left side. There was no statistically significant difference between right and left in the female and male autopsies or between sexes.

Conclusions: This anatomical study showed that structures in the anterior and middle cranial fossa can be reached via the supraorbital keyhole craniotomy approach with minimal brain retraction and adequate exposure and with minimal craniotomy size.