Orientation of endonasal transsphenoidal surgical trajectory and sella turcica anatomy by threedimensional computed tomography

Abstract

Objective To study the anatomy and oritention of nose,sella turcica in endonasal transsphenoidal approach by three dismension computer tomography (3D - CT).Methods CT data of nose and sella turcica in 29 cases was studied on retrospectively.The 3D configuration of nose and sella turcica were constructed and observed using image reconstruction with surgical clip image registration.The relation between sellar floor and the line from nose tip to apex of the ear helix ( nose tip ear apex line) was analyzed.The practicability of nose tip - ear apex line and 3D - CT to orient the sellar floor in endonasal transsphenoidal approach was evaluated in 14 patients with pituitary adenoma.Results Nose tip - ear apex line passed through the sphenoid sinus in 100％ of the cases and through the sellar floor in 42％ of the cases.The mean distance from the sellar floor - clivus point perpendicularly to the nose tip - ear apex line was (3.6 ± 1.8) mm.The 3D - CT imaging clearly and individually displayed the configuration of nose and sella turcica in sequential layers including sphenoid sinus,its bone septum,optic protuberance,carotid protuberance and sellar floor,thus can simulate transsphenoidal surgery and help to find sellar floor.Conclusion The 3D - CT imaging provides a best tool for visualizing the patient's anatomy preoperatively and more intuitively displaying the nose and sella turcica and helps to find sellar floor.The nose tip ear apex line can guide the surgical trajectory of the endonasal transsphenoidal approach. Key words: Pituitay adenoma; Endonasal transsphenoidal approach; Three dismension computer tomography