Investigation of the effect of anticoagulant usage in the flow diverter stent treatment of the patient-specific cerebral aneurysm using the Lagrangian coherent structures

• Published in: Journal of clinical neuroscience Vol. 94; pp. 86 - 93
• Main Authors: Tercanlı, Muhammed Furkan, Olcay, Ali Bahadır, Mutlu, Onur, Bilgin, Cem, Hakyemez, Bahattin
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.12.2021
• Subjects: Anticoagulants; Computational fluid dynamics; Flow diverter; Lagrangian coherent structures; Warfarin; Flow diverter; Anticoagulants; Warfarin; Lagrangian coherent structures; Computational fluid dynamics
• ISSN: 0967-5868; 1532-2653
• DOI: 10.1016/j.jocn.2021.10.007

•Anticoagulant usage in FD treatment affects hemodynamics at the aneurysm site.•CFD and LCS methods can provide how blood particles move with and without warfarin.•The warfarin decreased blood viscosity allowing more blood flow to enter inside the sac.•Only 12% of the seeded fluid particles stayed inside the sac for blood with warfarin case. Anticoagulants are prescribed to the flow diverter treated patients to diminish the risk of embolism in the arteries. In the present study, digital subtraction angiography images of a 49-year-old female patient with a left paraophthalmic aneurysm were used to build a numerical model to investigate the effect of an anticoagulant on hemodynamics at the aneurysm site. The Carreau-Yasuda viscosity model was utilized to define blood viscosity, and the coefficients of the viscosity model were updated based on the usage of warfarin. The five-cardiac cycle-long numerical simulations were performed, and Lagrangian coherent structures, hyperbolic time, and fluid particle analyses were also employed in the numerical models. These analyses allowed us to evaluate the formation of stagnated regions, recirculation zones, and the number of jailed particles inside the aneurysm sac following a flow diverter placement. It is realized that anticoagulant use caused blood to be less viscous, yielding a substantial amount of incoming blood flow to enter the aneurysm sac. Only 12% of the nearly 25,000 fluid particles seeded from the artery inlet have stayed inside the sac. Furthermore, the deviation between warfarin added blood and normal blood flow becomes more extensive, with every heartbeat undermining the effectiveness of patient-specific CFD models when the use of anticoagulants is overlooked in the viscosity models.