A new combined parameter predicts re-treatment for coil-embolized aneurysms: a computational fluid dynamics multivariable analysis study

Abstract

PurposeCoil embolization is a minimally invasive method used to treat cerebral aneurysms. Although this endovascular treatment has a high success rate, aneurysmal re-treatment due to recanalization remains a major problem of this method. The purpose of this study was to determine a combined parameter that can be useful for predicting aneurysmal re-treatment due to recanalization.MethodsPatient-specific geometries were used to retrospectively analyze the blood flow for 26 re-treated and 74 non-retreated aneurysms. Post-operatively aneurysms were evaluated at 12-month follow-up. The hemodynamic differences between the re-treatment and non-retreatment aneurysms were analyzed before and after coil embolization using computation fluid dynamics. Basic fluid characteristics, rates of change, morphological factors of aneurysms and patient-specific clinical information were examined. Multivariable analysis and logistic regression analysis were performed to determine a combined parameter—re-treatment predictor (RP).ResultsAmong examined hemodynamic, morphological, and clinical parameters, slight reduction of blood flow velocity rate in the aneurysm, slight increase of pressure rate at the aneurysmal neck and neck area, and hypertension were the main factors contributing to re-treatment. Notably, hemodynamic parameters between re-treatment and non-retreatment groups before embolization were similar: however, we observed significant differences between the groups in the post-embolization average velocity and the rate of reduction in this velocity in the aneurysmal dome.ConclusionsThe combined parameter, RP, which takes into consideration hemodynamic, morphological, and clinical parameters, accurately predicts aneurysm re-treatment. Calculation of RP before embolization may be able to predict the aneurysms that will require re-treatment.

Computational fluid dynamics as a risk assessment tool for aneurysm rupture

“…Estimation of recanalization risk has also been attempted using CFD. Fujimura et al 11 performed CFD analysis for 100 coil-embolized aneurysms, including repeat treatments due to recanalization and 74 aneurysms that were not re-treated. They developed a formula called "re-treatment predictor" to predict the risk of aneurysmal re-treatment using logistic regression.…”

Hemodynamic Differences Between Recurrent and Nonrecurrent Intracranial Aneurysms: Fluid Dynamics Simulations Based on MR Angiography

“…It was found that the inflow rate on basilar tip aneurysms was a predictor of recurrence after treatment and that changes of the velocity on the neck plane of the aneurysm after treatment were related to aneurysm recurrence . Fujimura et al even proposed a combined parameter combining hemodynamic, morphological, and clinical parameters to predict aneurysm retreatment . In their study the combined parameter more accurately predicted aneurysm retreatment than morphological parameters alone.…”

Numerical simulation techniques to predict aneurysm recanalization after coil embolization and their problems

“…When applying the solid model, some studies reconstructed the coil mass using images taken by diagnostic imaging devices, other studies artificially reproduced the state in which the coil mass is deployed by reconstructing the cerebral artery geometries only at locations where there was blood flow or by artificially removing the aneurysm above the aneurysm neck surface from images before coil embolization. [6,8,11,12,16]. Ten reports have adopted this method.…”

“…Due to the improvement of computational technology and improvement of image resolution from the development of diagnostic imaging equipment such as computed tomography (CT), magnetic resonance imaging (MRI), and digital subtraction angiography (DSA), an increasing amount of blood flow analysis using computational fluid dynamics (CFD) based on medical images have been performed [3][4][5]. This technique has also been introduced to investigate aneurysm recanalization, and multiple studies have been conducted so far [6][7][8][9][10][11][12]. CFD analysis were conducted on cases where coil embolization were performed, and it has been suggested that recanalization may be predicted by derived hemodynamic factors [8,10,12].…”

“…This technique has also been introduced to investigate aneurysm recanalization, and multiple studies have been conducted so far [6][7][8][9][10][11][12]. CFD analysis were conducted on cases where coil embolization were performed, and it has been suggested that recanalization may be predicted by derived hemodynamic factors [8,10,12]. The method in which the coil is modeled and deployed in an aneurysm is a major issue when performing CFD analysis to predict recanalization.…”