Morphometry of the aortic arch and its branches. A computed tomography angiography-based study

Background: The current study aims to determine the prevalence of variations of the aortic arch using computed tomography angiography (CTA), as well as morphometries and gender correlations.Materials and methods: A retrospective, transverse, observational and descriptive study of 220 CTA was performed. The branching pattern, most cranial vertebral level of the aortic arch, area of the proximal, middle and distal segments of the arch, area of each branch, and the path of atypical arteries were recorded. Results were analysed and stratified by gender.Results: The typical aortic arch branching pattern was present in 77.7% without statistical significance between genders. The most common variant was a two-branch pattern with a common trunk and a left subclavian (13.6%), followed by a typical branching pattern with an added left vertebral artery (7.3%). T3 was the most frequent cranial level (32.3%), followed by T2–T3 (26.8%), and T3–T4 (23.2%). The mean areas of the aortic arch were 685.5 ± 183.9, 476.1 ± 124.1, and 445.0 ± 145.1 mm2 for the proximal, middle and distal segments, with statistical difference between men and women in the middle and distal segments. Three paths of atypical arteries were identified: bifurcated vertebral artery (0.5%), aberrant right subclavian artery (0.5%), and left subclavian ostium obstruction (0.5%).Conclusions: Mexican population has one of the highest prevalence of variations in the aortic arch branching pattern. The high probability of finding these should be taken into consideration when assessing patients. A standardised classification method would contemplate future un-reported findings, without causing confusion by the different numbers assigned by each author

Volumetric assessment of the sella turcica: a reevaluation

Background: The sella turcica volume is widely measured by the Di Chiro-Nelson method. The purpose is to compare the fidelity of a proposed volumetry method versus the Di Chiro-Nelson method, using Computed Tomography (CT) images. Materials and methods: Morphometric examination of 173 CT were included, of which 52.6% were female. The mean age was 53.2 ± 17.6 years. Considering the Di Chiro-Nelson method, two measurements were added for each axis in the CT evaluation: Length (Central, Left, and Right), Width (Central, Anterior, and Posterior), and Height (Central, Left, and Right). Results: The mean measurements were Length: Central 10.11 ± 1.44, Left 7.45 ± 1.67, Right 7.53 ± 1.59; Width: Central 12.27 ± 2.11, Anterior 10.99 ± 1.92, Posterior 10.10 ± 1.74; Height: Central 7.68 ± 1.38, Left 7.16 ± 1.35, Right 7.40 ± 1.41. A statistically significant difference between sex was found only in the anterior width (p=0.01). Using the proposed method, the volume was 342.2 ± 88.5 and 378. 6 ± 113.9 mm3 respectively between females and males (p=0.02) versus 476.1 ± 132.4 and 523.8 ± 186.0 mm3 (p=0.05) using the Di Chiro-Nelson’s method. Conclusions: Women had significantly smaller sella turcica volume than men. This proposed method considers the sella turcica as a not strictly symmetrical structure and indicates reduced variation between the maximum and minimum values, compared to the Di Chiro-Nelson’s. Our findings may be useful to reassess the volume of the sella turcica as the measurements indicate a higher precision

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 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. 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