Anatomical aspects of optic nerve decompression in transcranial and transsphenoidal approach

Abstract

Purpose: The proximal portion of the optic nerve is quite prone to injury at the entrance of the optic foramen by tumoral or traumatic pathologies. As a result, it is important to show which way and which part we can effectively and safely decompress the pathologies affecting the optic nerves. In this study, we compared the decompression of the proximal segment of the optic canal Likewise, we investigated the anatomy and histopathology of the opticocarotid region from below and above.

Materials and methods: A total of 30 adult sellar and parasellar samples were extracted from human cadavers. Anatomical dissection and histological examination were performed from transcranial and transsphenoidal ways. The walls of the proximal optic canal were evaluated with an operating microscope and endoscope. The relationship between the optic canal, the internal carotid artery, and the optic nerve were qualitatively and quantitatively examined.

Results: Similar rates of circular optic canal decompression were achieved by each approach; however, by means of decompression, the transsphenoidal approach was superior for the inferior and medial portions of the optic nerve and transcranial approach was superior for the superior and lateral portions and also more appropriate for optic nerve mobilization.

Conclusion: This is one of the first studies to reveal the ways of the decompression of the proximal optic canal by transcranial and transsphenoidal approaches. According to this study, the medial and inferior proximal portions of the optic nerves are histologically more prone to injury caused by traction or compression. Transcranial or transsphenoidal approach should be preferred according to the location of the pathology and anatomical and histological characteristics of this region.

Keywords: Optic canal; Optic nerve; Optic nerve decompression; Transcranial approach; Transsphenoidal approach.