Endoscopic Anatomy Study On The Transethmoidal Sinus Approach For Resection Of Anterior Skull Base Tumor

Objective To provide the anatomical reference of anterior skull base surgery on endoscopic endonasal by studying the anatomy of sinus-related anterior skull base and its adjacent structures and approaching reveal scope and operative space of this operative approach. Methods (1) Ten cadaveric heads of adults fixed by formalin(20sides)which the marinate carotid artery and internal jugular vein were perfused with red latex and blue latex respectively were operated on according to Messerklinger's form to expose to the anterior ethmoid sinus and the posterior ethmoid sinus on endoscopic endonasal exclusively, and the middle turbinate was resected to expose to the cribriform plate,the cribriform capula and the frontal recesses completely ,then the anterior skull base and the tuberculum sellae were abraded to expose to dura and cut open it , photos of the structures related to the approach were taken. The distance from the base of the columella to each anatomical stucture and the angles between the floor of nasal cavity and line from the base of the columella to each anatomical stucture were measured. (2) Head CT data of 15 patients with pituitary adenoma were used to observe and measure the osseous structures with neuronavigation guided. Results The measured distance and angles were 54.0mm±4.8mm,57.0°±5.0°for the frontal recesses;43.5mm±3.5mm,49.5°±5.5°for the uncinate process;46.5mm±3.3mm,48.5°±3.5°for the bulla ethmoidalis;58mm±4.0mm,52.0°±5.5°for the anterior ethmoid artery;65.8mm±3.5mm,41.5°±3.5°for the posterior ethmoid artery;53.4mm±3.6mm,50.0°±4.5°for the middle cribriform plate;68.2mm±5.5mm,38.5°±3.5°for juncture of the sphenethmoid; 76.4mm±3.3mm,33.5°±5.5°for the optic cranial orifices;22.4mm±4.5mm for two sides of the medial orbital wall;17.3mm±2.4mm for two sides of the optic cranial orifices;40.3mm±3.6mm for the distance from the apertura sinus frontalis to the tuberculum sellae. Conclusion Endoscopic endonasal transethmoidal sinus approach can easily reach the anterior skull base and expose to anterior skull base area from the aperture sinus frontalis to the sphenoid sinus between two sides of the medial orbital wall,and can remove anterior skull base tumors completely in selected cases.