Surgical management of arterial compression of the anterior visual pathway - a systematic review.

Introduction: Visual loss secondary to a vascular loop or atherosclerotic carotid has been a controversial topic for many years with contemporary data supporting its existence. The role of surgery in the management of this entity is not well defined. We performed a systematic review describing the different surgical techniques and outcomes.

Method: A search strategy was devised in accordance with the 2020 Preferred Reporting Items of Systematic Reviews and Meta-Analyses (PRISMA) statement. An electronic search was performed from the databases Pubmed, Google scholar, Scopus and Web of Science databases. The search was performed from inception until the 10th of December 2023.

Results: A total of 2469 articles were screened with 15 articles describing 18 patients being included. Of these cases, eleven involved compression due to unilateral or bilateral dolichoectatic internal carotid artery (ICA), three for a dolichoectatic anterior cerebral artery (ACA), two for a combination of a dolichoectatic ICA with a dorsolateral ophthalmic artery and two for a combination of a dolichoectatic ICA and ACA.

Conclusion: Two distinct compressive entities can be differentiated. Compressive optic neuropathy at the entrance of the optic canal due to pinching between an ectatic carotid and the falciform ligament. A second entity is due to compression of the cisternal optic nerve or chiasm secondary tot a vascular loop. A variety of surgical techniques have been described and include: unroofing of the optic canal with sectioning of the falciform ligament; microvascular decompression with a Teflon pellet, a muscle patch or, rerouting of the offending vessel with a sling. Larger and prospective studies are needed to better define the role of surgery in this, probably, underreported pathology.