Changes in the Relative Displacement between the Supra-Aortic Branches with Age.

BACKGROUND: This study aimed to determine the normal ranges for the height and deflection angle of the aortic arch and the displacement distances between the supra-aortic branches in relation to age, sex, body mass index (BMI), and body surface area (BSA) in adults without aortic disease using non-contrast chest computed tomography (CT). METHODS: The CT scans of 700 patients were analyzed. We measured the height and deflection angle of the aortic arch based on the lower level of the pulmonary artery bifurcation. The displacement distances between the supra-aortic branches in the coronal and sagittal planes were measured, and the deflection angles between these branches were calculated. Multiple linear regression analysis was used to investigate the associations of age, sex, BMI, and BSA with these aortic arch parameters. RESULTS: The height of the aortic arch was significantly higher (74 ± 15 mm vs. 65 ± 12 mm, P < 0.001) and the left-posterior displacement distance of the left subclavian artery (LSA) to the innominate artery (IA) was greater in men than that in women. The height and deflection angle of the aortic arch increased with age. The distance by which the LSA was shifted to the left posterior of the left common carotid artery and to the left of the IA increased with age. CONCLUSIONS: The normal aging process is accompanied by morphological changes in the aortic arch and relative displacement between the supra-aortic branches. Identifying these parameters could lead to a comprehensive understanding of the anatomy and morphology of the aortic arch.

Simulation Analysis of Limit Operating Specifications for Onshore Spoolable Reinforced Thermoplastic Pipes.

Spoolable reinforced plastic line pipes (RTPs), exhibiting a series of advantages such as good flexibility, few joints, long single length, light weight, easy installation, etc., have been widely used in the onshore oil and gas industry such as oil and gas gathering and transportation, high pressure alcohol injection, water injection, sewage treatment, and other fields. However, due to the lack of clear standard specificationof the limit operating properties for RTPs, three typical failure modes, i.e., tensile, flexure, and torsion, frequently occur in terrain changes, construction operation, and subsequent application, which seriously affects the promotion and use of RTPs. In this paper, the stress distribution of a non-bonded polyester fiber reinforced high-density polyethylene (HDPE) pipe (DN 150, PN 2.5 MPa) was systematically studied by the finite element method (FEM), and then the limit operating values under the axial tensile, coiled bending, and torsion load were determined. The corresponding experiments were conducted to validate the reliability and accuracy of the FEM model. The FEM results showed that the critical strain for axial tensile was 3%, the minimum respooling bend radius was 1016.286 mm, and the limit torsion angle of this RTP was 58.77°, which are very close to the experimental results. These limit values will be useful to establish normative guidelines for field construction and failure prevention of onshore RTP.

Endovascular treatment of isolated spontaneous celiac artery dissection.

This report presents the case of a patient with isolated spontaneous celiac artery dissection. The patient developed acute abdominal pain that was induced by eating. Computed tomography and selective angiography revealed an intimal flap that separated the true and false lumens located 3 cm from the origin of the celiac artery. We treated the patient with a stent that was deployed endovascularly into the celiac artery to seal the entry site. Postoperative angiography revealed that the graft was patent and the follow-up period was uneventful. The etiology, clinical features, diagnostic modalities and treatment options of isolated spontaneous celiac artery dissection are reported.