Anatomical study on sphenoidal sinus location in endoscopic endonasal transsphenoidal surgery for pituitary tumors

Objective:To provide anatomical basis for endoscopic endonasal transsphenoidal surgery for pituidary tumors. Methods: The structures in nasal cavity and sphenoidal sinus were observed and measured in 25 adult cadaveric head specimens and the structures in sphenoidal sinus and sellar area were observed under the operating endoscope in 9 fresh adult cadaveric head specimens. Results: The distance from the base of columella to the ostia of sphenoidal sinus was 65.3±3.1 mm. The distance from the base of nasus to the ostia of sphenoidal sinus was 45.4±2.4 mm. The distance from the ostia of sphenoidal sinus to the roof of the sphenoethmoid concavity was 7.1±3.4 mm. The vertical distance from the root of sellar area to line between the base of columella and middle turbinate was 12.1±2.0 mm. The distance from the upper and lower end of the ostia of sphenoidal sinus to the midline were 3.0±1.0 mm and 3.9±1.2 mm respectively. The transverse diameter of the ostia of sphenoidal sinus was 1.3±0.5 mm. The sagittal diameter of the ostia of sphenoidal sinus was 3.3±1.5 mm. Conclusion: With these anatomical landmarks, sellar area can be easily located in endoscopic endonasal transsphenoidal surgery for pituitary tumors.