Utilizing computational fluid dynamics to understand the collateral flow of the Circle of Willis during cerebral vasospasm and its clinical implications

Rupture of cerebral aneurysms causes subarachnoid hemorrhage, a severe form of stroke. These patients are at high risk of an acute ischemic event, described as cerebral vasospasm. Our understanding of which patients will develop symptomatic vasospasm, and when they do, is limited. Thus, there is a need to accurately predict which patients will require aggressive intervention with vasospasm. The goal of my research is to develop a model using computational fluid dynamics (CFD) that allows clinicians to identify which patients will develop symptomatic vasospasm. Whereas CFD has been used in other fields, there is a paucity of research using CFD to assess the Circle of Willis, a redundant network of cerebral blood vessels, and its role in providing collateral blood flow during vasospasm. First, I will retrospectively create virtual angiograms utilizing patients’ computed tomography and transcranial Doppler (TCD) ultrasound of their cerebral blood flow to simulate a virtual representation of their cerebral blood flow at baseline, with the goal of fine tuning this model and process. Second, I will apply this model to patients in vasospasm to better understand anatomical variants and TCD thresholds that correlate with patients who will require endovascular treatment versus standalone blood pressure augmentation.