title: Finite element analysis of helical flows in human aortic arch: a novel index.
abstract: This study investigates the helical secondary flows in the aortic arch using finite element analysis. The relationship between helical flow and the configuration of the aorta in patients of whose three-dimensional images constructed from computed tomography scans was examined. A finite element model of the pressurized root, arch, and supra-aortic vessels was developed to simulate the pattern of helical secondary flows. Calculations indicate that most of the helical secondary flow was formed in the ascending aorta. Angle α between the zero reference point and the aortic ostium (correlation coefficient (r) = -0.851, P = 0.001), the dispersion index of the cross section of the ascending (r = 0.683, P = 0.021) and descending aorta (r = 0.732, P = 0.010), all correlated closely with the presence of helical flow (P < 0.05). Stepwise multiple linear regression analysis confirmed angel α to be independently associated with the helical flow pattern in therein (standardized coefficients = -0.721, P = 0.023). The presence of helical fluid motion based on the atherosclerotic risks of patients, including those associated with diabetes, hypertension, hyperlipidemia, or renal insufficiency, was also evaluated. Numerical simulation of the flow patterns in aortas incorporating the atherosclerotic risks may better explain the mechanism of formation of helical flows and provide insight into causative factors that underlie them.
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Chang Gung Memorial Hospital-Linkou, Tao-Yuan, Taiwan ; Department of Mechanical Engineering, Chang Gung University, Tao-Yuan, Taiwan.
authors.forename: Cheng-Hung
authors.initials: CH
authors.lastname: Lee
authors.affiliation: Department of Mechanical Engineering, Chang Gung University, Tao-Yuan, Taiwan ; Department of Cardiovascular Surgery, Chang Gung Memorial Hospital-Linkou, Tao-Yuan, Taiwan.
authors.forename: Kuo-Sheng
authors.initials: KS
authors.lastname: Liu
authors.affiliation: Graduate Institute of Medical Mechatronics, Chang Gung University, Tao-Yuan, Taiwan.
authors.forename: Guan-Heng
authors.initials: GH
authors.lastname: Jhong
authors.affiliation: Department of Mechanical Engineering, Chang Gung University, Tao-Yuan, Taiwan.
authors.forename: Shih-Jung
authors.initials: SJ
authors.lastname: Liu
authors.affiliation: Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital, Linkou, Tao-Yuan, Taiwan.
authors.forename: Ming-Yi
authors.initials: MY
authors.lastname: Hsu
authors.affiliation: Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital, Linkou, Tao-Yuan, Taiwan.
authors.forename: Chao-Jan
authors.initials: CJ
authors.lastname: Wang
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Chang Gung Memorial Hospital-Linkou, Tao-Yuan, Taiwan.
authors.forename: Kuo-Chun
authors.initials: KC
authors.lastname: Hung