ASSESSING THE HEMODYNAMIC EFFECTS OF BYPASS SURGERY ON GIANT INTRACRANIAL ANEURYSMS USING FLUID-STRUCTURE INTERACTION SIMULATIONS

• Published in: International journal of artificial organs Vol. 46; no. 7; p. 429
• Main Authors: Reorowicz, P, Tyfa, Z, Wisniewski, K, Jaskolski, D, Jozwik, K, Obidowski, D
• Format: Journal Article
• Language: English
• Published: Milan Wichtig Editore s.r.l 01-07-2023
• Subjects: Aneurysm; Aneurysms; Arteries; Blood flow; Blood pressure; Blood vessels; Brain damage; Brain injury; Circulatory system; Comparative analysis; Computational fluid dynamics; Computational neuroscience; Configurations; Fluid dynamics; Fluid-structure interaction; Hemodynamics; Hydrodynamics; Localization; Mechanical properties; Medical imaging; Neuroimaging; Pressure distribution; Shear stress; Simulation; Software; Surgery; Thromboembolism; Thrombosis
• ISSN: 0391-3988; 1724-6040

Objectives: The term GIA means intracranial aneurysm larger than 25 mm whose rupture usually leads to death or serious brain damage. Among all methods of treating these cerebrovascular pathologies, one can distinguish bypassing. It means that neurosurgeons cut off the blood inflow to the aneurysm sac and they create an additional connection to distal arteries. Such a connection preserves proper blood supply to all efferent arteries. However, there is one question that remains unanswered – which cerebral perforator should be chosen as the vessel to which the bypass should be anchored. It is impossible to predict the outcomes of each possibility in clinical practice, whereas with computational fluid dynamics (CFD) tools obtaining such an answer becomes feasible. Therefore, the main objective of this research was to perform virtual bypassing procedures and observe which configuration was optimal for the given patient. Methods: The geometry of the arterial system, including the giant aneurysm, was reconstructed basing on biomedical imaging scans. Then, two variants of the bypass were proposed. After conducting a series of fluid-structure interaction (FSI) simulations with elastic walls assumption, flow hemodynamics in the cerebral region was assessed (including shear stress, blood distribution, pressure distribution and aneurysm volume). Results: A comparative analysis of three cases showed a strong effect of the bypass configuration on the flow conditions inside the aneurysm. Differences in WSS, OSI, TAWSS and viscosity were noted. A significant decrease in pressure and consequently aneurysm shrinkage was observed. Additionally, areas susceptible to thrombosis were identified. Conclusions: Results obtained from in-silico analyses can be used as an additional source of knowledge about the circulatory system affected by the bypassing surgeries. Conducted simulations indicated a beneficial effect of bypassing procedures on the mechanical load on the vessel walls. Moreover, they proved that a degree of affinity to possible thrombus formation depends on the bypass localization.