Small-bubble transport and splitting dynamics in a symmetric bifurcation

• Published in: Computer methods in biomechanics and biomedical engineering Vol. 20; no. 11; pp. 1182 - 1194
• Main Authors: Qamar, Adnan, Warnez, Matthew, Valassis, Doug T., Guetzko, Megan E., Bull, Joseph L.
• Format: Journal Article
• Language: English
• Published: England Taylor & Francis 18.08.2017; Taylor & Francis Ltd
• Subjects: Arteries - physiology; Bifurcations; Blood; bubble splitting; Bubbles; Cancer; Computational fluid dynamics; Computer simulation; Damage detection; Embolization, Therapeutic; Fluid flow; Friction; Gas embolotherapy; Gravitation; Gravity; Homogeneity; Humans; Mechanical stimuli; Microbubbles; Models, Theoretical; Numerical Analysis, Computer-Assisted; Physical properties; Reynolds number; Shear stress; shear stress in bifurcation; Shearing; Skin; Splitting; Stress, Mechanical; volume of fluid; shear stress in bifurcation; volume of fluid; bubble splitting; Gas embolotherapy
• ISSN: 1025-5842; 1476-8259
• DOI: 10.1080/10255842.2017.1340466

Simulations of small bubbles traveling through symmetric bifurcations are conducted to garner information pertinent to gas embolotherapy, a potential cancer treatment. Gas embolotherapy procedures use intra-arterial bubbles to occlude tumor blood supply. As bubbles pass through bifurcations in the blood stream nonhomogeneous splitting and undesirable bioeffects may occur. To aid development of gas embolotherapy techniques, a volume of fluid method is used to model the splitting process of gas bubbles passing through artery and arteriole bifurcations. The model reproduces the variety of splitting behaviors observed experimentally, including the bubble reversal phenomenon. Splitting homogeneity and maximum shear stress along the vessel walls is predicted over a variety of physical parameters. Small bubbles, having initial length less than twice the vessel diameter, were found unlikely to split in the presence of gravitational asymmetry. Maximum shear stresses were found to decrease exponentially with increasing Reynolds number. Vortex-induced shearing near the bifurcation is identified as a possible mechanism for endothelial cell damage.