"Sagittal Crest": Definition, Stepwise Dissection, and Clinical Implications From a Transorbital Perspective
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Updated: Oct 1, 2025
Microvascular Decompression: Salient Surgical Principles and Technical Nuances
Published on: July 5, 2011
Francesco Corrivetti1,2, Matteo de Notaris1,2, Alberto Di Somma3,4
1Department of Neuroscience, Neurosurgery Operative Unit, "San Pio" Hospital, Benevento, Italy.
Background:
The recent development of the superior eyelid endoscopic transorbital approach (SETOA) offered a new route for the management of cavernous sinus and middle cranial fossa tumors. As a result, a constant anatomic landmark of the surgical pathway after drilling the medial edge of the greater sphenoid wing (GSW) is represented by a triangular-shaped bone ridge appearing as a "crest."
Objective:
To perform an anatomic study to define this surgical landmark, named the "sagittal crest" (SC) as seen from the transorbital endoscopic view.
Methods:
Four adult cadaveric specimens (8 sides) were dissected performing an endoscopic transorbital approach to the middle fossa and the SC was removed to perform interdural opening of the cavernous sinus. Computed tomography scans were made before and after removal of the SC to perform quantitative analysis and building a 3-dimensional model of the bone resection of the GSW via the SETOA.
Results:
The SC is a bone ridge triangle shaping dorsally the superior orbital fissure resulting as the residual fragment after drilling the lateral aspect of the greater sphenoid wing. Predissection and postdissection computed tomography scans allowed to objectively assess SC features and dimensions (mean 1.08 ± 0.2 cm).
Conclusion:
The SC is a constant anatomic landmark constituted of the residual medial portion of the GSW. Complete resection of this key landmark provides adequate working space and appears to be mandatory during SETOA to guide the subsequent interdural dissection of the lateral wall of cavernous sinus.
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