The Study of Hemodynamics Phenomena in Intracranial Aneurysms with Computational Fluid Dynamics (CFD): A PRISMA - Compliant Systematic Review

Aneurysms are pathological dilatations of some parts of the human vascular system and are characterized by thin and dilated regions in the arterial wall. The most common aneurysm is the intracranial aneurysms (IAs) which consist of dilatations of cerebral arteries circle. The causes of IAs have been investigated so long and so hard over the years and the majority of researchers agree that hemodynamic phenomena like blood flow play an important role in the formation, growing, and rupture of a brain aneurysm. However, proposed experiments, with the aim of a better understanding of the characteristics of blood flow in aneurysms, are still difficult to take. OBJECTIVE: The objective of this study was to review the literature on the overall clinical importance of blood flow in IAs and to compare early categories of numerical analysis of blood flow. METHODS: The author performed a systematic electronic search in the PubMed database over the last 5 years using the terms Numerical analysis of blood flow and hemodynamic phenomena. RESULTS: 450 full-text manuscripts were retrieved and 437 were excluded due to inclusion criteria. The Computacional Fluid Dynamics (CFD) approach was used in overall studies to perform numerical simulations with vascular wall models and numerical modeling of cerebral arteries, to describe the blood flows of the models of giant cerebral aneurysm before and after flow diverter implantation at the aneurysmal sac and to evaluate flow modification effects introduced by endovascular therapy in real treatment cases. Changes in blood flow, before and after stent deployment, are presented in some studies. For instance, Wall Shear Stress (WSS) on the aneurysmal sac dropped from 0.69 Pa to 0.48 Pa after the flow diverter implantation; CONCLUSION: The CFD methods can be effectively used to evaluate changes in blood flow before and after diverter implantation, describe the behavior of the cerebral vascular walls in a realistic fashion.