Finite element modeling of endovascular coiling and flow diversion enables hemodynamic prediction of complex treatment strategies for intracranial aneurysm

Abstract

Endovascular interventions using coil embolization and flow diversion are becoming the mainstream treatment for intracranial aneurysms (IAs). To help assess the effect of intervention strategies on aneurysm hemodynamics and treatment outcome, we have developed a finite-element-method (FEM)-based technique for coil deployment along with our HiFiVS technique for flow diverter (FD) deployment in patient-specific IAs. We tested four clinical intervention strategies: coiling (1–8 coils), single FD, FD with adjunctive coils (1–8 coils), and overlapping FDs. By evaluating post-treatment hemodynamics using computational fluid dynamics (CFD), we compared the flow-modification performance of these strategies. Results show that a single FD provides more reduction in inflow rate than low PD coiling, but less reduction in average velocity inside the aneurysm. Adjunctive coils add no additional reduction of inflow rate beyond a single FD until coil PD exceeds 11%. This suggests that the main role of FDs is to divert inflow, while that of coils is to create stasis in the aneurysm. Overlapping FDs decreases inflow rate, average velocity, and average wall shear stress (WSS) in the aneurysm sac, but adding a third FD produces minimal additional reduction. In conclusion, our FEM-based techniques for virtual coiling and flow diversion enable recapitulation of complex endovascular intervention strategies and detailed hemodynamics to identify hemodynamic factors that affect treatment outcome.

Safety and efficacy of flow re-direction endoluminal device (FRED) in the treatment of cerebral aneurysms: a single center experience

“…Computational tools for simulating clinical interventions and hemodynamics in patient-specific intracranial aneurysms helped to evaluate the impact of various intervention strategies and identify hemodynamic factors that affect treatment outcome [11,32].…”

Virtual stenting workflow with vessel-specific initialization and adaptive expansion for neurovascular stents and flow diverters

“…Currently a number of virtual intervention tools are available (Ma, et al 2012, Appanaboyina, et al 2009, Larrabide, et al 2012, Spranger, et al 2014, Cebral et al 2005, Damiano et al 2015) but none has been adopted by the clinicians, largely because these tools lack the computational efficiency and an easy streamlined structure to be translated to the clinical settings, or are not accurate enough to represent the actual deployed stents in patient-specific aneurysms. The current study addresses this problem by developing a virtual stenting tool for neurovascular stents and flow diverters aimed at potential clinical use.…”

Compacting a Single Flow Diverter versus Overlapping Flow Diverters for Intracranial Aneurysms: A Computational Study

“…To simulate the deployment of two overlapped FDs, we ran two independent HiFiVS simulations consecutively. 7 Following the deployment of the first FD in each IA (5×20 mm, 4.5×20 mm, and 3.25×14 mm for the fusiform, large, and medium IA, respectively), a second FD measuring 5×20 mm, 4.5×14 mm, and 3.25×12 mm was coaxially deployed in the fusiform, large, and medium IA, respectively.…”

“…6 More recently, we simulated realistic deployment of the Pipeline Embolization Device and demonstrated that overlapping two reduced aneurysmal flow velocity 30% more than deploying one. 7 …”