Safety window for the transsphenoidal approach for pituitary tumours: 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 analysed 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 mm² and 147.60 mm² 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.

Morphometric variants of the paranasal sinuses in a Mexican population: expected changes according to age and gender.

BACKGROUND: There are developmental variations in the paranasal sinuses. Our objective was to determine their dimensions and volume stratified by age and sex and define the expected growth pattern. MATERIALS AND METHODS: A retrospective, observational study was performed including computed tomography (CT) of patients between 1 and 20 years of age. The volumes of the frontal, sphenoid, and maxillary sinuses were obtained. RESULTS: A total of 210 CT were included with a mean age of 10 ± 6.1 years, 106 (50.5%) were female. Groups were categorised in ranges of 5 years. Spearman correlation coefficients between the right and left sides were 0.843, 0.711, 0.916 for the frontal, sphenoid and maxillary sinuses. Post-hoc for the categorical age groups demonstrated statistically significant differences with values of p < 0.01, except between age groups 11-15 against ≥ 16 years of age (p = 0.8). Gender-related differences were evident with a higher air volume in girls in the 5-10-year-old group, while boys predominated in the rest of the groups. CONCLUSIONS: Computed tomography is ideal for pre-surgical sinus assessment. The maximum volume of paranasal sinuses is reached at the age of 15. There is a clear volumetric difference between age and gender groups. There is a direct relationship between a volume and its contralateral counterpart.