title: A Methodology for Verifying Abdominal Aortic Aneurysm Wall Stress.
abstract: An abdominal aortic aneurysm (AAA) is a permanent focal dilatation of the abdominal aorta of at least 1.5 times its normal diameter. Although the criterion of maximum diameter is still used in clinical practice to decide on a timely intervention, numerical studies have demonstrated the importance of other geometric factors. However, the major drawback of numerical studies is that they must be validated experimentally before clinical implementation. This work presents a new methodology to verify wall stress predicted from the numerical studies against the experimental testing. To this end, four AAA phantoms were manufactured using vacuum casting. The geometry of each phantom was subject to microcomputed tomography (μCT) scanning at zero and three other intraluminal pressures: 80, 100, and 120 mm Hg. A zero-pressure geometry algorithm was used to calculate the wall stress in the phantom, while the numerical wall stress was calculated with a finite-element analysis (FEA) solver based on the actual zero-pressure geometry subjected to 80, 100, and 120 mm Hg intraluminal pressure loading. Results demonstrate the moderate accuracy of this methodology with small relative differences in the average wall stress (1.14%). Additionally, the contribution of geometric factors to the wall stress distribution was statistically analyzed for the four phantoms. The results showed a significant correlation between wall thickness and mean curvature (MC) with wall stress.
authors.affiliation: Department of Mechanical Engineering, TECNUN, University of Navarra, Paseo Manuel de Lardizabal, 13, San Sebastián 20018, Spain e-mail: sruiz@tecnun.es.
authors.forename: Sergio
authors.initials: S
authors.lastname: Ruiz de Galarreta
authors.affiliation: Department of Mechanical Engineering, TECNUN, University of Navarra, Paseo Manuel de Lardizabal, 13, San Sebastián 20018, Spain e-mail: acazon@tecnun.es.
authors.forename: Aitor
authors.initials: A
authors.lastname: Cazón
authors.affiliation: Department of Mechanical Engineering, TECNUN, University of Navarra, Paseo Manuel de Lardizabal, 13, San Sebastián 20018, Spain e-mail: ranton@tecnun.es.
authors.forename: Raúl
authors.initials: R
authors.lastname: Antón
authors.affiliation: Department of Biomedical Engineering, The University of Texas at San Antonio, One UTSA Circle, AET 1.360, San Antonio, TX 78249-0669 e-mail: ender.finol@utsa.edu.
authors.forename: Ender A
authors.initials: EA
authors.lastname: Finol
mesh_terms: D000465:Algorithms; D001012:Aorta, Abdominal / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D017544:Aortic Aneurysm, Abdominal / Q000175:diagnosis* / Q000503:physiopathology*; D001783:Blood Flow Velocity; D001794:Blood Pressure; D003198:Computer Simulation; D006801:Humans; D008955:Models, Cardiovascular; D019047:Phantoms, Imaging; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods; D033081:Shear Strength; D013314:Stress, Mechanical; D014057:Tomography, X-Ray Computed / Q000295:instrumentation / Q000379:methods*