title: Patient-specific assessment of hemodynamics by computational fluid dynamics in patients with bicuspid aortopathy.
abstract: Hemodynamics related to eccentric blood flow may factor into the development of bicuspid aortic valve aortopathy. We investigated wall shear stress distribution by means of magnetic resonance imaging-based computational fluid dynamics in patients with a bicuspid aortic valve.
  
  
  
  Included were 12 patients with a bicuspid aortic valve (aortic stenosis, n = 11; root enlargement, n = 1). Three patients with a normal tricuspid aortic valve (arch aneurysm, n = 1; descending aortic aneurysm, n = 2) were included for comparison. The thoracic aorta geometry was reconstructed by means of 3-dimensional computed tomography angiography, and the bicuspid aortic valve orifice was modeled. Flow rates at the sinotubular junction and 3 aortic branches were measured at various time points by cine phase-contrast magnetic resonance imaging to define boundary conditions for computational fluid dynamics, and the flow was simulated.
  
  
  
  Bicuspid aortic valve cusp configurations were type 0 lateral (n = 4), type 0 anterior-posterior (n = 2), type 1 L-R (n = 4), and type 1 R-N (n = 2). Abnormal aortic helical flow was seen in the ascending aorta and transverse arch in all patients with bicuspid aortic valves and was right handed in 11 patients (91%). No such flow was seen in the patients with tricuspid aortic valves. The patients with bicuspid aortic valves were likely to have jet flow/wall impingement against the greater curvature of the proximal ascending aorta, resulting in remarkably increased wall shear stress around the impingement area.
  
  
  
  Computational fluid dynamics simulation is useful for precise evaluation of hemodynamics related to bicuspid aortic valve aortopathy. Such evaluation will advance our understanding of the disease pathophysiology and may facilitate molecular biological investigation.
authors.affiliation: Department of Cardiovascular Surgery, Saitama Medical Center, Jichi Medical University, Saitama, Japan. Electronic address: kimura-n@omiya.jichi.ac.jp.
authors.forename: Naoyuki
authors.initials: N
authors.lastname: Kimura
authors.affiliation: Department of Mechanical Engineering, Biomechanics Laboratory, Saitama University, Saitama, Japan. Electronic address: masanorin@mech.saitama-u.ac.jp.
authors.forename: Masanori
authors.initials: M
authors.lastname: Nakamura
authors.affiliation: Department of Mechanical Engineering, Biomechanics Laboratory, Saitama University, Saitama, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Komiya
authors.affiliation: Department of Cardiovascular Surgery, Saitama Medical Center, Jichi Medical University, Saitama, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Nishi
authors.affiliation: Department of Cardiovascular Surgery, Saitama Medical Center, Jichi Medical University, Saitama, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Yamaguchi
authors.affiliation: Department of Radiology, Saitama Medical Center, Jichi Medical University, Saitama, Japan.
authors.forename: Osamu
authors.initials: O
authors.lastname: Tanaka
authors.affiliation: Division of Cardiovascular Surgery, Department of Surgery, Jichi Medical University, Saitama, Japan.
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Misawa
authors.affiliation: Department of Cardiovascular Surgery, Saitama Medical Center, Jichi Medical University, Saitama, Japan.
authors.forename: Hideo
authors.initials: H
authors.lastname: Adachi
authors.affiliation: Division of Cardiovascular Surgery, Department of Surgery, Jichi Medical University, Saitama, Japan.
authors.forename: Koji
authors.initials: K
authors.lastname: Kawahito
mesh_terms: D000328:Adult; D000368:Aged; D001013:Aorta, Thoracic / Q000000981:diagnostic imaging* / Q000503:physiopathology; D001014:Aortic Aneurysm / Q000000981:diagnostic imaging* / Q000209:etiology / Q000503:physiopathology; D001021:Aortic Valve / Q000002:abnormalities* / Q000000981:diagnostic imaging / Q000503:physiopathology; D001024:Aortic Valve Stenosis / Q000000981:diagnostic imaging* / Q000209:etiology / Q000503:physiopathology; D000082882:Bicuspid Aortic Valve Disease; D001696:Biomechanical Phenomena; D005260:Female; D006349:Heart Valve Diseases / Q000150:complications / Q000000981:diagnostic imaging* / Q000503:physiopathology; D006439:Hemodynamics; D006801:Humans; D057446:Hydrodynamics; D019028:Magnetic Resonance Imaging, Cine; D008297:Male; D008875:Middle Aged; D008955:Models, Cardiovascular; D066230:Patient-Specific Modeling; D055420:Perfusion Imaging / Q000379:methods*; D011237:Predictive Value of Tests
keywords: aortopathy; bicuspid aortic valve; computational fluid dynamics; wall shear stress