title: Computed wall stress may predict the growth of abdominal aortic aneurysm.
abstract: Growth rate of abdominal aortic aneurysm (AAA) is thought to be an important indicator of the potential risk of rupture. Wall stress is also thought to be a trigger for its rupture. However, stress change during the expansion of an AAA is unclear. Forty-four patients with AAAs were included in this longitudinal follow-up study. They were assessed by serial abdominal ultrasonography and computerized tomography (CT) scans if a critical size was reached or a rapid expansion occurred. Patient-specific 3-dimensional AAA geometries were reconstructed from the follow-up CT images. Structural analysis was performed to calculate the wall stresses of the AAA models at both baseline and final visit. A non-linear large-strain finite element method was used to compute the wall stress distribution. The average growth rate was 0.66 cm/year (range 0-1.32 cm/year). A significantly positive correlation between shoulder tress at baseline and growth rate was found (r=0.342; p=0.02). A higher shoulder stress is associated with a rapidly expanding AAA. Therefore, it may be useful for estimating the growth expansion of AAAs and further risk stratification of patients with AAAs.
authors.affiliation: State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, 210096 China. zylicam@gmail.com
authors.forename: Zhi-Yong
authors.initials: ZY
authors.lastname: Li
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D017544:Aortic Aneurysm, Abdominal / Q000000981:diagnostic imaging / Q000473:pathology* / Q000628:therapy; D001794:Blood Pressure; D005260:Female; D020342:Finite Element Analysis; D005500:Follow-Up Studies; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D012306:Risk; D013314:Stress, Mechanical; D014057:Tomography, X-Ray Computed / Q000379:methods