Implementation of computer simulation to assess flow diversion treatment outcomes: systematic review and meta-analysis

Abstract

IntroductionDespite a decade of research into virtual stent deployment and the post-stenting aneurysmal hemodynamics, the hemodynamic factors which correlate with successful treatment remain inconclusive. We aimed to examine the differences in various post-treatment hemodynamic parameters between successfully and unsuccessfully treated cases, and to quantify the additional flow diversion achievable through stent compaction or insertion of a second stent.MethodsA systematic review and meta-analysis were performed on eligible studies published from 2000 to 2019. We first classified cases according to treatment success (aneurysm occlusion) and then calculated the pooled standardized mean differences (SMD) of each available parameter to examine their association with clinical outcomes. Any additional flow diversion arising from the two common strategies for improving the stent wire density was quantified by pooling the results of such studies.ResultsWe found that differences in the aneurysmal inflow rate (SMD −6.05, 95% CI −10.87 to −1.23, p=0.01) and energy loss (SMD −5.28, 95% CI −7.09 to −3.46, p<0.001) between the successfully and unsuccessfully treated groups were indicative of statistical significance, in contrast to wall shear stress (p=0.37), intra-aneurysmal average velocity (p=0.09), vortex core-line length (p=0.46), and shear rate (p=0.09). Compacting a single stent could achieve additional flow diversion comparable to that by dual-stent implantation.ConclusionsInflow rate and energy loss have shown promise as identifiers to discriminate between successful and unsuccessful treatment, pending future research into their diagnostic performance to establish optimal cut-off values.

VICTORIA: VIrtual neck Curve and True Ostium Reconstruction of Intracranial Aneurysms

“…These observations are in line with previous findings such as segmentation-dependent variations in energy loss calculations or differences in the neck inflow rate between successfully and unsuccessfully treated aneurysm patients. [ 31 , 39 ] However, for most contributions within VICTORIA almost similar hemodynamic results were obtained and largest deviations were associated with outlying and clinically insufficient contributions. Nevertheless, the parameter of interest should be critically observed (e.g., increased shear close to the neck region) when the separation of the aneurysm from its parent vessel is realized.…”

Critical Angiographic and Sonographic Analysis of Intra Aneurysmal and Downstream Hemodynamic Changes After Flow Diversion

“…As evidenced by the exhaustive literature involving CFD simulation, several key hemodynamic parameters have been identified as important predictors of successful thrombosis ( 17 ). However, despite the plethora of studies demonstrating the relationship between simulated hemodynamics and outcome, the CFD methodology remains utilized mostly in the research domain with little implications in routine clinical practice.…”

Evaluation of aneurysm rupture risk based upon flowrate-independent hemodynamic parameters: a multi-center pilot study

“…Aneurysm hemodynamics was resolved by use of the ANSYS-CFX solver (ANSYS Inc, Canonsburg, PA), with the convergence criterion set as the maximum residuals of the normalized continuity and velocity being less than 10 −5 . Due to their possible association with aneurysm rupture and patient outcomes,3 25 26 we extracted the aneurysmal WSS and EL from converged simulation results corresponding to each simulated condition.…”