Endoscopic Endonasal Supraoptic And Infraoptic Approaches For Complex "Farasuprasellar" Lesions: Surgical Anatomy,Technique Nuances,and Case Series

OBJECTIVE: Surgical management of lesions involving the lateral area of the suprasellar region,including the lateral aspect of the planum sphenoidale and a tight junction region of the optic canal(OC),the anterior clinoid process(ACP),and the internal carotid artery(ICA)and its dural rings,is extremely challenging.Here,these regions are described from the endonasal perspective,namely,the “parasuprasellar”area.Moreover,the authors introduce two novel endoscopic endonasal supraoptic(EESO)and endoscopic endonasal infraoptic(EEIO)approaches to access the parasuprasellar area.METHODS: Surgical simulation of the EESO and EEIO approaches to the parasuprasellar area was conducted in 5 silicon-injected specimens.The same techniques were applied in 12 patients involving the parasuprasellar area;the medical records,surgical results and complications were further analyzed.RESULTS: The EESO approach provided excellent surgical access to the lateral region of the planum sphenoidale,which corresponds to the orbital gyrus of the frontal lobe.With stepwise bone(OC,optic strut and ACP)removal,dissociation of the ophthalmic artery(OA)and optic nerve(ON),the EEIO approach,enables access to the lateral region of the supraclinoidal ICA.These approaches can be used independently or in combination,but are more often employed as a complement to the endoscopic endonasal midline approach and transcavernous approach.In clinical application,the EESO and EEIO approaches were successfully performed in 12 patients harboring tumors as well as multiple aneurysms involving the parasuprasellar area.Gross total and subtotal tumor resection was achieved in 9patients and 1 patient,respectively.For two patients with multiple aneurysms,the lesions were clipped selectively according to location and size.Visual acuity improved in 7 patients,remained stable in 4,and deteriorated in only 1.No postoperative intracranial infection or ICA injury occurred in this series.CONCLUSIONS: The EESO and EEIO approaches offer an original treatment option for well-selected lesions involving the parasuprasellar area.They can be combined with the current endoscopic endonasal midline approach and transcavernous approach to remove extensive pathologies involving the intrasellar,suprasellar,sphenoid,and cavernous sinuses and even bifurcation of the ICA.The work for the first time pushes the boundary of the endoscopic endonasal approach lateral to the supraclinoidal ICA and ON and adds a new territory(parasuprasellar area)for the lateral skull base.