Safety window for the transsphenoidal approach for pituitary tumors: a computed tomographic angiography study

Background: The aims are to evaluate the morphometry of the sellar region and propose a safety window on the floor of the sella turcica for the transsphenoidal approach in a Hispanic population. Materials and methods: We retrospectively analyzed 150 computed tomographic angiography sellar region images from asymptomatic patients. The images were evaluated intraobservatory by an expert radiologist. We measured: intercarotid distance of cavernous segment; depth of sella turcica; skull base angle; anterior distance, the distance between anterior spinal nasal and floor of the sella turcica; posterior distance, the distance between anterior spinal nasal and posterior wall of the sella turcica; anterior surgical angle, formed between the floor of the nostril and superior limit of the anterior wall of the sella turcica; and posterior angle, formed between the floor of the nostril and the inferior limit of the posterior wall of the sella turcica. Results: Safety window was based on two measures: the intercarotid distance and depth. The mean of the safety window is 151.13 mm 2 and 147.60 mm 2 for men and women respectively. The intercarotid distance was 17.83 mm. The depth of the sella turcica was 8.46 mm. The skull base angle was 112.13 grades. The anterior distance was 76.34 mm. The posterior distance was 87.59 mm. The anterior surgical angle was 32.76 grades. The posterior surgical angle was 87.59 grades. Conclusions: The surgical approach space is smaller in females. It could significate a more complicated surgery in this population. Anatomical understanding could reduce complications in hospitals without a neuronavigation system. The project was previously reviewed and approved by the local ethics and research committees of the University with the approval number AH19-00002 on April 25, 2019.