The Application Of Endoscopic Endonasal Transsphenoidal Approach To The Top Of The Basilar Artery

Objective: To observe the anatomic characteristics of the nasal endoscopic transsphenoidal approach to the tip of the basilar artery,and to investigate the feasibility of clipping the basilar artery aneurism with this approach,so as to provide anatomical evidence for its clinical popularization.Methods: Collected the clinical cases according to the inclusion criteria.Input the imaging data onto the neuronavigation system.The individual 3-D digital model was reconstructed and the relevant anatomical structures were measured.Preparated the cadaveric head specimens of perfusion.Open the sphenoid sinus through the sphenoid sinus-clivus approach using the nasal endoscopy of 0°and 30°.Removed the bone of the sellar floor and the slope and cut the dura mater.Exposed the blood vessels and nerves surrounding the top of the basilar artery fully.Simulate the operation of clipping the aneurysm from the top of the basilar artery.Measured the length and width of the window in skull base.Results: The distance from phenoid sinus to optic nerve eminence,internal carotid artery carina,sellar tuberculum sellae,the midpoint of olivary eminence and dorsum sellae respectively is(10.8+1.7)mm,(11.4+2.1)mm,(17.2+2.9)mm,(14.7+2.3)mm,(22.5+3.5)mm.The distance between the midline and canales pterygoideus,foramina lacerum,hypoglossal canal,internal carotid artery and the front of occipital condyle respectively is(8.9+0.8)mm(left),(9.0+0.8)mm(right),(10.3+1.4)mm(left),(10.6+1.3)mm(right),(16.9+1.3)mm(left),(16.8+1.2)mm(right),(24.5+1.3)mm(left),(24.4+1.3)mm(right),(8.0+0.8)mm(left),(7.9+0.9)mm(right).The basilar artery(BA),superior cerebellar artery(SCA),P1 segment of the posterior cerebral artery(PCA)and posterior communicating artery(Pco A)can be fully exposed with the anatomic operation under nasal endoscope through sphenoid sinus-slope approach.The width of the bone window in skull base is(8.95 + 0.38)mm and the length is(51.62 + 2)mm.Conclusions: There is no obstacle to the top of the basilar artery through the endonasal transsphenoidal approach.We may try to use the endoscopic to clip the aneurysm from the top of the basilar artery with this approach.