Effects of Vessel Tortuosity on Coronary Hemodynamics: An Idealized and Patient-Specific Computational Study.
Although coronary tortuosity can influence the hemodynamics of coronary arteries, the relationship between tortuosity and flow has not been thoroughly investigated partly due to the absence of a widely accepted definition of tortuosity and the lack of patient-specific studies that analyze complete coronary trees. Using a computational approach we investigated the effects of tortuosity on coronary flow parameters including pressure drop, wall shear stress, and helical flow strength as measured by helicity intensity. Our analysis considered idealized and patient-specific geometries. Overall results indicate that perfusion pressure decreases with increased tortuosity, but the patient-specific results show that more tortuous vessels have higher physiological wall shear stress values. Differences between the idealized and patient-specific results reveal that an accurate representation of coronary tortuosity must account for all relevant geometric aspects, including curvature imposed by the heart shape. The patient-specific results exhibit a strong correlation between tortuosity and helicity intensity, and the corresponding helical flow contributes directly to the observed increase in wall shear stress. Therefore, helicity intensity may prove helpful in developing a universal parameter to describe tortuosity and assess its impact on patient health. Our data suggest that increased tortuosity could have a deleterious impact via a reduction in coronary perfusion pressure, but the attendant increase in wall shear stress could afford protection against atherosclerosis.
Department of Mechanical Engineering, Virginia Tech, Blacksburg, VA, USA.
Natalya
N
Vorobtsova
Laboratory of Biological Structure Mechanics (LaBS), Department of Chemistry, Materials and Chemical Engineering "Giulio Natta", Politecnico di Milano, Milan, Italy.|Department of Biomedical Engineering, Thoraxcenter, Erasmus University Medical Center, Rotterdam, The Netherlands.
Claudio
C
Chiastra
Department of Biomedical Engineering and Mechanics, Virginia Tech, Blacksburg, VA, USA.
Mark A
MA
Stremler
Section of Cardiology, Carilion Clinic, Virginia Tech Carilion School of Medicine, Roanoke, VA, USA.
David C
DC
Sane
Laboratory of Biological Structure Mechanics (LaBS), Department of Chemistry, Materials and Chemical Engineering "Giulio Natta", Politecnico di Milano, Milan, Italy.
Francesco
F
Migliavacca
School of Mechanical Engineering, Purdue University, 585 Purdue Mall, West Lafayette, IN, USA. pvlachos@purdue.edu.
Pavlos
0000-0002-8040-9257
P
Vlachos
D050197:Atherosclerosis / Q000000981:diagnostic imaging / Q000503:physiopathology*; D001783:Blood Flow Velocity; D003198:Computer Simulation; D003326:Coronary Circulation; D003331:Coronary Vessels / Q000000981:diagnostic imaging / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D008955:Models, Cardiovascular; D033081:Shear Strength
Computational fluid dynamics; Coronary artery; Helicity; Tortuosity; Wall shear stress