Phantom-based experimental validation of fast virtual deployment of self-expandable stents for cerebral aneurysms

Abstract

BackgroundEndovascular intervention using a stent is a mainstream treatment for cerebral aneurysms. To assess the effect of intervention strategies on aneurysm hemodynamics, we have developed a fast virtual stenting (FVS) technique to simulate stent deployment in patient-specific aneurysms. However, quantitative validation of the FVS against experimental data has not been fully addressed. In this study, we performed in vitro analysis of a patient-specific model to illustrate the realism and usability of this novel FVS technique.MethodsWe selected a patient-specific aneurysm and reproduced it in a manufactured realistic aneurismal phantom. Three numerical simulation models of the aneurysm with an Enterprise stent were constructed. Three models were constructed to obtain the stented aneurysms: a physical phantom scanned by micro-CT, fast virtual stenting technique and finite element method. The flow in the three models was simulated using a computational fluid dynamics software package, and the hemodynamics parameters for the three models were calculated and analyzed.ResultsThe computational hemodynamics in the patient-specific aneurysm of the three models resembled the very well. A qualitative comparison revealed high similarity in the wall shear stress, streamline, and velocity plane among the three different methods. Quantitative comparisons revealed that the difference ratios of the hemodynamic parameters were less than 10%, with the difference ratios for area average of wall shear stress in the aneurysm being very low.ConclusionsIn conclusion, the results of the computational hemodynamics indicate that FVS is suitable for evaluation of the hemodynamic factors that affect treatment outcomes.

Association between hemodynamic modifications and clinical outcome of intracranial aneurysms treated using flow diverters

“…We have validated the deployment and post-implantation results of VSW in a patient-specific IA geometry treated using the neurovascular Enterprise stent. [8] We are currently working towards validating the FD deployment results obtained from VSW against experimental deployment results in IA silicone phantoms, and post-treatment hemodynamic predictions after FD implantation against experimental velocity measurements using particle image velocimetry.…”

“…We then used the previously mentioned VSW [6–8] to recapitulate the process of FD deployment in each IA geometry. The workflow consists of three steps: (1) Preprocessing: isolation of the parent vessel and generation of a generic simplex mesh structure along the vessel centerline using vessel-specific initialization.…”

“…However, in order to obtain post-treatment hemodynamics, the deployment of FDs in patient-specific IAs need to be simulated. We have recently developed an efficient virtual stenting workflow (VSW), [6–8] that can simulate the clinical intervention of FDs in IA geometries. This virtual intervention followed by CFD can provide insights on contrasting blood flow modifications in different clinical outcomes, and identify hemodynamic modification that are associated with pro-thrombotic conditions.…”

Predisposing factors for recanalization of cerebral aneurysms after endovascular embolization: a multivariate study

“…To calculate the hemodynamics of the aneurysms, we applied our previously developed computational modeling methods 12. A novel virtual stenting technique13 14 and a porous media method12 were used to simulate the in vivo Enterprise stent and coil mass, respectively. Hemodynamics parameters based on CFD were performed under pulsatile flow conditions using commercial software (ANSYS CFX 14.0; ANSYS, Inc, Canonsburg, Pennsylvania, USA).…”

Preface: Computational and experimental methods for biological research: cardiovascular diseases and beyond

“…Li et al [12] studied the pressure shielding ability of stent-graft after endovascular aneurysm repair (EVAR) of abdominal aortic aneurysm (AAA). Zhang introduced a phantom-based experimental validation of fast virtual deployment of self-expandable stents for cerebral aneurysms [13]. Xu and Liu studied potential association between flow instability and rupture in patients with matched-pairs of ruptured-unruptured intracranial aneurysms [14].…”