LE STUDIUM Visiting Researcher
In residence at
Dr Ayache Bouakaz
The Role of Haemodynamics in Intracranial Bifurcation Arteries after Aneurysm Treatment with Flow-Diverting Stents
Intracranial aneurysms (IAs) are balloon-like focal deformations of a blood vessel in the brain, carrying an inherent risk of rupture and bleeding with severe consequences for the patient. When intervention is advocated, clinicians have several options to treat IAs. A minimally invasive option consists of deploying a medical device (Flow Diverting Stent or FDS) to divert flow from the aneurysm, triggering blood coagulation inside the aneurysmal sac to stop or prevent any existing or potential bleeding. In certain circumstances this treatment causes the occlusion of the arteries surrounding the aneurysm, leading to obstruction of normal blood flow to the brain, and ultimately permanent and often irreversible damage (stroke). The causes behind this complication are not fully understood but there is a strong consensus in the literature that the underlying causes might be associated with adverse alterations to the pre-treatment blood flow in the vascular network surrounding the aneurysm. Unfortunately, these complications are currently preventing the widespread use of this minimally invasive treatment option that would ultimately reduce risk, hospitalization and healthcare costs. Stent-induced alterations to blood flow in a blood vessel can be analysed using a computer model that reproduces, virtually and accurately, the mechanical and anatomical environment of the problem, or by using 3D printed vascular models and a blood mimicking fluid to study the problem experimentally. This project will attempt to identify, through the use of image-based computer models and ultrasound-based experimental analysis, the possible cause-effect mechanisms, mediated by blood flow, which may explain under what circumstances the deployment of an FDS causes significant changes to flow and ultimately vessel occlusion. The long-term aim is that of providing guidance to clinicians towards a safer and more effective treatment of this condition.
Narata AP, Moura F, Larrabide I, Chapot R, Cognard C, Januel AC, Velasco S, Bouakaz A, Patat F, and Marzo A. Role of distal cerebral vasculature in vessel constriction after aneurysm treatment with flow diverter stentsJournal of NeuroInterventional Surgery 2020;12:818-826. Benemerito I, Narata AP, Narracott A and Marzo A. Determining Clinically-Viable Biomarkers for Ischaemic Stroke Through a Mechanistic and Machine Learning Approach. Ann Biomed Eng 50, 740–750 (2022). https://doi.org/10.1007/s10439-022-02956-7