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Jeken-Rico P, Chau Y, Goetz A, Lannelongue V, Sédat J, Hachem E. Virtual flow diverter deployment and embedding for hemodynamic simulations. Comput Biol Med 2024; 180:109023. [PMID: 39163828 DOI: 10.1016/j.compbiomed.2024.109023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2024] [Revised: 08/03/2024] [Accepted: 08/11/2024] [Indexed: 08/22/2024]
Abstract
Flow-diverter stents offer clinicians an effective solution for treating intracranial aneurysms, especially in cases where other devices may be unsuitable. However, strongly deviating success rates among different centres, manufacturers, and aneurysm phenotypes highlight the need for better in-situ studies of these devices. To support research in this area, virtual stenting algorithms have been proposed that, combined with computational fluid dynamics, provide insights into the hemodynamic alterations induced by the device. Yet, many existing algorithms rely on uncertain parameters, such as the forces applied during operation, fail to predict the length of the device after deployment, or lack robust validation steps, raising concerns about their reliability. Therefore, we developed a robust deployment technique that builds upon the geometrical features of the vessel and includes advancements from previous works. The algorithm is detailed and validated against literature examples, in-vitro experiments, and patient data, achieving a mean angular error below 5° in the latter. Furthermore, we describe and demonstrate how the deployed device can be embedded in a computational mesh using open-source tools and anisotropic meshing routines.
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Affiliation(s)
- Pablo Jeken-Rico
- Mines Paris, Université PSL, CEMEF, UMR7635 CNRS, Sophia Antipolis, 06904, France.
| | - Yves Chau
- Department of Neuro-Interventional and Vascular Interventional, University Hospital of Nice, Nice, 06000, France
| | - Aurèle Goetz
- Mines Paris, Université PSL, CEMEF, UMR7635 CNRS, Sophia Antipolis, 06904, France
| | - Vincent Lannelongue
- Mines Paris, Université PSL, CEMEF, UMR7635 CNRS, Sophia Antipolis, 06904, France
| | - Jacques Sédat
- Department of Neuro-Interventional and Vascular Interventional, University Hospital of Nice, Nice, 06000, France
| | - Elie Hachem
- Mines Paris, Université PSL, CEMEF, UMR7635 CNRS, Sophia Antipolis, 06904, France
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2
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Abdollahi R, Shahi A, Roy D, Lessard S, Mongrain R, Soulez G. Virtual and analytical self-expandable braided stent treatment models. Med Eng Phys 2024; 126:104145. [PMID: 38621838 DOI: 10.1016/j.medengphy.2024.104145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Revised: 02/25/2024] [Accepted: 03/09/2024] [Indexed: 04/17/2024]
Abstract
The Flow Diverter is a self-expandable braided stent that has helped improve the effectiveness of cerebral aneurysm treatment during the last decade. The Flow Diverter's efficiency heavily relies on proper decision-making during the pre-operative phase, which is currently based on static measurements that fail to account for vessel or tissue deformation. In the context of providing realistic measurements, a biomechanical computational method is designed to aid physicians in predicting patient-specific treatment outcomes. The method integrates virtual and analytical treatment models, validated against experimental mechanical tests, and two patient treatment outcomes. In the case of both patients, deployed stent length was one of the validated result parameters, which displayed an error inferior to 1.5% for the virtual and analytical models. These results indicated both models' accuracy. However, the analytical model provided more accurate results with a 0.3% error while requiring a lower computational cost for length prediction. This computational method can offer designing and testing platforms for predicting possible intervention-related complications, patient-specific medical device designs, and pre-operative planning to automate interventional procedures.
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Affiliation(s)
- Reza Abdollahi
- Faculté de médecine, Université de Montréal, H3T 1J4, Montréal, Canada; Centre de Recherche du Centre Hospitalier de l'Université de Montréal, H2X 0A9, Montréal, Canada
| | - Amirali Shahi
- Faculté de médecine, Université de Montréal, H3T 1J4, Montréal, Canada; Centre de Recherche du Centre Hospitalier de l'Université de Montréal, H2X 0A9, Montréal, Canada
| | - Daniel Roy
- Faculté de médecine, Université de Montréal, H3T 1J4, Montréal, Canada; Département de Radiologie, Centre Hospitalier de l'Université de Montréal, H2X 0C1, Montréal, Canada
| | - Simon Lessard
- Centre de Recherche du Centre Hospitalier de l'Université de Montréal, H2X 0A9, Montréal, Canada; École de Technologie Supérieure, H3C 1K3, Montréal, Canada
| | - Rosaire Mongrain
- Mechanical Engineering Department, McGill University, H3A 0C3, Montréal, Canada
| | - Gilles Soulez
- Faculté de médecine, Université de Montréal, H3T 1J4, Montréal, Canada; Centre de Recherche du Centre Hospitalier de l'Université de Montréal, H2X 0A9, Montréal, Canada; Département de Radiologie, Centre Hospitalier de l'Université de Montréal, H2X 0C1, Montréal, Canada.
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3
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Ubachs R, van der Sluis O, Smith S, Mertens J. Computational modeling of braided venous stents - Effect of design features and device-tissue interaction on stent performance. J Mech Behav Biomed Mater 2023; 142:105857. [PMID: 37099918 DOI: 10.1016/j.jmbbm.2023.105857] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Revised: 03/25/2023] [Accepted: 04/12/2023] [Indexed: 04/28/2023]
Abstract
Designing venous stents with desired properties is challenging due to the partly conflicting performance criteria, e.g., enhancing flexibility may be at odds with increasing patency. To evaluate the effect of design parameters on the mechanical performance of braided stents, computational simulations are performed using finite element analysis. Model validation is performed through comparison with measurements. Considered design features are stent length, wire diameter, pick rate, number of wires, and stent end-type, being either open-ended or closed looped. Based on the requirements of venous stents, tests are defined to study the effect of design variations with respect to the following key performance criteria: chronic outward force, crush resistance, conformability, and foreshortening. Computational modeling is demonstrated to be a valuable tool in the design process through its ability of assessing sensitivities of various performance metrics to the design parameters. Additionally, it is shown, using computational modeling, that the interaction between a braided stent and its surrounding anatomy has a significant impact on its performance. Therefore, taking into account device-tissue interaction is crucial for the proper assessment of stent performance.
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Affiliation(s)
- René Ubachs
- Philips Research, High Tech Campus 34, 5656 AE Eindhoven, The Netherlands
| | - Olaf van der Sluis
- Philips Research, High Tech Campus 34, 5656 AE Eindhoven, The Netherlands; Eindhoven University of Technology, Eindhoven, The Netherlands.
| | - Scott Smith
- Philips Image Guided Therapy Devices, 5905 Nathan Lane, Plymouth, MN, United States
| | - Jake Mertens
- Philips Image Guided Therapy Devices, 5905 Nathan Lane, Plymouth, MN, United States
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4
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Bisighini B, Aguirre M, Biancolini ME, Trovalusci F, Perrin D, Avril S, Pierrat B. Machine learning and reduced order modelling for the simulation of braided stent deployment. Front Physiol 2023; 14:1148540. [PMID: 37064913 PMCID: PMC10090671 DOI: 10.3389/fphys.2023.1148540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Accepted: 03/16/2023] [Indexed: 03/31/2023] Open
Abstract
Endoluminal reconstruction using flow diverters represents a novel paradigm for the minimally invasive treatment of intracranial aneurysms. The configuration assumed by these very dense braided stents once deployed within the parent vessel is not easily predictable and medical volumetric images alone may be insufficient to plan the treatment satisfactorily. Therefore, here we propose a fast and accurate machine learning and reduced order modelling framework, based on finite element simulations, to assist practitioners in the planning and interventional stages. It consists of a first classification step to determine a priori whether a simulation will be successful (good conformity between stent and vessel) or not from a clinical perspective, followed by a regression step that provides an approximated solution of the deployed stent configuration. The latter is achieved using a non-intrusive reduced order modelling scheme that combines the proper orthogonal decomposition algorithm and Gaussian process regression. The workflow was validated on an idealized intracranial artery with a saccular aneurysm and the effect of six geometrical and surgical parameters on the outcome of stent deployment was studied. We trained six machine learning models on a dataset of varying size and obtained classifiers with up to 95% accuracy in predicting the deployment outcome. The support vector machine model outperformed the others when considering a small dataset of 50 training cases, with an accuracy of 93% and a specificity of 97%. On the other hand, real-time predictions of the stent deployed configuration were achieved with an average validation error between predicted and high-fidelity results never greater than the spatial resolution of 3D rotational angiography, the imaging technique with the best spatial resolution (0.15 mm). Such accurate predictions can be reached even with a small database of 47 simulations: by increasing the training simulations to 147, the average prediction error is reduced to 0.07 mm. These results are promising as they demonstrate the ability of these techniques to achieve simulations within a few milliseconds while retaining the mechanical realism and predictability of the stent deployed configuration.
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Affiliation(s)
- Beatrice Bisighini
- Mines Saint-Étienne, University Lyon, University Jean Monnet, INSERM, Saint-Étienne, France
- Predisurge, Grande Usine Creative 2, Saint-Etienne, France
- Department of Enterprise Engineering, University Tor Vergata, Rome, Italy
| | - Miquel Aguirre
- Mines Saint-Étienne, University Lyon, University Jean Monnet, INSERM, Saint-Étienne, France
- Laboratori de Càlcul Numèric, Universitat Politècnica de Catalunya, Barcelona, Spain
- International Centre for Numerical Methods in Engineering (CIMNE), Gran Capità, Barcelona, Spain
| | | | | | - David Perrin
- Predisurge, Grande Usine Creative 2, Saint-Etienne, France
| | - Stéphane Avril
- Mines Saint-Étienne, University Lyon, University Jean Monnet, INSERM, Saint-Étienne, France
| | - Baptiste Pierrat
- Mines Saint-Étienne, University Lyon, University Jean Monnet, INSERM, Saint-Étienne, France
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5
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Tong X, Han M, Wu Z, Feng X, Liu A. Effects of different stent size selection on pipeline embolization device treatment of intracranial aneurysms. Ther Adv Neurol Disord 2023; 16:17562864231151475. [PMID: 36776531 PMCID: PMC9909058 DOI: 10.1177/17562864231151475] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2022] [Accepted: 12/29/2022] [Indexed: 02/09/2023] Open
Abstract
Background Pipeline embolization device (PED) is becoming increasingly common in therapeutic practice. In idealized model studies, treatment effectiveness may vary with different stent sizes in the same vasculature. The true effect of stent size selection in the clinical setting remains unknown, however. Objective To determine the true effect of stent size selection in the clinical setting. Design It is a retrospective review. Methods A retrospective review was conducted on consecutive patients with aneurysms treated with a PED at our institution. The primary exposures were the difference between the diameter of the stent and the parent artery (DD) and the difference between the length of the stent and the aneurysm neck (DL). The outcomes were the clinical and angiographic results, perioperative complications, balloon application, and in-stent stenosis. The results were generated using univariable and multivariable logistic regression and restricted cubic spline (RCS) curves. Results A larger DD was significantly associated with incomplete occlusion [odds ratio (OR) = 2.37; 95% confidence interval (CI) = 1.43-3.98; p < 0.001], while a larger DL was significantly associated with balloon application (OR = 1.12; 95% CI = 1.02-1.23; p = 0.021) and in-stent stenosis (>25%) (OR = 1.07; 95% CI = 1.01-1.16; p = 0.042). The RCS curve indicated that the risk of incomplete occlusion increased as the DD became larger, the possibility of balloon application increased as the DL increased when the DL was >5.7 mm, and the risk of in-stent stenosis (>25%) increased as the DL increased. Conclusion In the clinical setting, stent selection was associated with treatment effectiveness and may add to the treatment burden. These occurrences should be considered for aneurysms treated with PED.
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Affiliation(s)
| | | | - Zhongxue Wu
- Neurointerventional Center, Beijing Neurosurgical Institute and Beijing Tiantan Hospital, Capital University, Beijing, China
| | - Xin Feng
- Neurosurgery Center, Department of Cerebrovascular Surgery, Engineering Technology Research Center of Education Ministry of China on Diagnosis and Treatment of Cerebrovascular Disease, Zhujiang Hospital, Southern Medical University, Guangzhou 510280, China,Guangdong Provincial Key Laboratory on Brain Function Repair and Regeneration, Guangzhou, China
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6
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Lucchetti A, Emonts C, Idrissi A, Gries T, Vaughan TJ. An experimental investigation of the mechanical performance of PLLA wire-braided stents. J Mech Behav Biomed Mater 2023; 138:105568. [PMID: 36459705 DOI: 10.1016/j.jmbbm.2022.105568] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 11/09/2022] [Accepted: 11/11/2022] [Indexed: 11/20/2022]
Abstract
Much of our current understanding of the performance of self-expanding wire-braided stents is based on mechanical testing of Nitinol-based or polymeric non-bioresorbable (e.g. PET, PP etc.) devices. The small amount of data present for bioresorbable devices characterizes stents with big nominal diameters (D>6mm), with a distinct lack of data describing the mechanical performance of small-diameter wire-braided bioresorbable devices (D≤5mm). This study presents a systematic investigation of the mechanical performance of wire-braided bioresorbable Poly-L-Lactic Acid (PLLA) stents having different braiding angles (α=45° , α=30°, and α=20°), wire diameters (d=100μm, and d=150μm), wire count (n=24 and n=48), braiding patterns (1:1-1, 2:2-1 and 1:1-2) and stent diameters (D=5mm, D=4mm, and D=2.5mm). Mechanical characterisation was carried out by evaluating the radial, longitudinal and bending response of the devices. Our results showed that smaller braid angles, larger wire diameters, higher number of wires and smaller stent diameter led to an increase in the stent mechanical properties across each of the three mechanical tests performed. It was found that geometrical features of a polymeric braided stent could be adapted to achieve a similar performance to the one of a metallic device. In particular, substantial increases in stent mechanical properties were found for a low braiding angle and when the braiding pattern followed a one-over-one-under configuration with two wires in parallel (1:1-2). Finally, it was shown that a mathematical model proposed in literature for metal braided stents can provide reasonable predictions also of polymeric stent performance but just in circumstances where wire friction does not have a dominant role. This study presents a wide range of experimental data that can provide an important reference for further development of wire-braided bioresorbable devices.
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Affiliation(s)
| | - Caroline Emonts
- Institut für Textiltechnik of RWTH Aachen University, Germany
| | - Akram Idrissi
- Institut für Textiltechnik of RWTH Aachen University, Germany
| | - Thomas Gries
- Institut für Textiltechnik of RWTH Aachen University, Germany
| | - Ted J Vaughan
- Biomechanics Research Centre (BioMEC), School of Engineering, College of Science and Engineering, University of Galway, Ireland.
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7
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Tong X, Shan Y, Leng X, Chen J, Fiehler J, Siddiqui AH, Hu X, Liu A, Xiang J. Predicting flow diverter sizing using the AneuGuide TM software: a validation study. J Neurointerv Surg 2023; 15:57-62. [PMID: 35039401 DOI: 10.1136/neurintsurg-2021-018353] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Accepted: 12/23/2021] [Indexed: 12/16/2022]
Abstract
BACKGROUND Stent sizing remains a challenging task for flow diverter implantation because of stent foreshortening. In this study, we aimed to quantify the change in length after implantation and assess the error in length prediction using AneuGuideTM software. METHODS In a retrospective cohort of 101 patients with 102 aneurysms undergoing treatment with a pipeline embolization device (PED; Covidien, Irvine, California, USA), we used AneuGuideTM software to obtain measured lengths (ML) and calculated lengths (CL) after stent implantation. Stent elongation was defined as the ratio of ML-LL to the labeled length (LL). Simulation error was defined as the ratio of the absolute value of CL-ML to ML. The correlation and consistency between ML and LL and between ML and CL were analyzed using Pearson's correlation test and the Bland-Altman plot. Statistical significance was set at p<0.05. RESULTS The mean elongation of ML was 32.6% (range 26.3-109.2%). Moderate consistency was observed between LL and ML (ρ=0.74, p<0.001). With the AneuGuideTM software, the mean simulation error was 6.6% (range 0.32-21.2%). Pearson's correlation test and the Bland-Altman plot showed a high correlation and consistency between ML and CL (ρ=0.96, p<0.001). CONCLUSION Labeled length provides only a low reference value for predicting the actual length of the flow diverter after implantation. The high consistency between ML and CL obtained from AneuGuideTM software shows its great potential for the optimization of the flow diverter sizing process.
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Affiliation(s)
- Xin Tong
- Neurointervention Center, Beijing Neurosurgical Institute and Beijing Tiantan Hospital, Beijing, China
| | - Yejie Shan
- ArteryFlow Technology Co., Ltd, Hangzhou, China
| | | | - Jigang Chen
- Neurointervention Center, Beijing Neurosurgical Institute and Beijing Tiantan Hospital, Beijing, China
| | - Jens Fiehler
- Department of Neuroradiology, University Medical Center Hamburg Eppendorf, Hamburg, Germany
| | - Adnan H Siddiqui
- Neurosurgery and Radiology and Canon Stroke and Vascular Research Center, University at Buffalo Jacobs School of Medicine and Biomedical Sciences, Buffalo, New York, USA
| | - Xuebin Hu
- Department of Neurosurgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Aihua Liu
- Neurointervention Center, Beijing Neurosurgical Institute and Beijing Tiantan Hospital, Beijing, China
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8
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Kishore K, Bodani V, Olatunji RB, Spears J, Marotta TR, Pereira VM. PREDICT: Precise deployment of Silk Vista Baby in confined territory: A technical note. Interv Neuroradiol 2022:15910199221142640. [PMID: 36457289 DOI: 10.1177/15910199221142640] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2024] Open
Abstract
Flow diverters (FD) have become increasingly useful in treating complex intracranial aneurysms, particularly wide-necked and recurrent aneurysms. Their use has progressively expanded to smaller vessels beyond the circle of Willis (CoW), and Silk Vista Baby (SVB) is one such low-profile FD which stands out because of deliverability through a 0.017″ microcatheter and smoother navigability. Precise deployment of SVB, specifically, the proximal end, can be challenging in certain anatomical locations when the proximal landing zone is very short, limited by vessel bifurcation or important branches arising from the artery or its geometry. We present our series to describe our technique and rule to 'PREDICT' the final deployment of SVB in real time, and discuss the nuances, exceptions and bail-out strategies. Using this technique, we were able to precisely deploy SVB in distal intracranial vessels with a mean proximal landing zone as short as 2.6 mm in 80% instances, requiring bail-out strategies in only 20% cases. This rule can be reliably followed in treating complex intracranial aneurysms with SVB FD within a confined territory, until validated software-based real-time planning tools are developed.
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Affiliation(s)
- Kislay Kishore
- Division of Neurosurgery, 10071St. Michael's Hospital, University of Toronto, Toronto, Canada
- Division of Interventional Neuroradiology, 10071St. Michael's Hospital, University of Toronto, Toronto, Canada
| | - Vivek Bodani
- Division of Neurosurgery, 10071St. Michael's Hospital, University of Toronto, Toronto, Canada
- Division of Interventional Neuroradiology, 10071St. Michael's Hospital, University of Toronto, Toronto, Canada
| | - Richard B Olatunji
- Division of Interventional Neuroradiology, 10071St. Michael's Hospital, University of Toronto, Toronto, Canada
| | - Julian Spears
- Division of Neurosurgery, 10071St. Michael's Hospital, University of Toronto, Toronto, Canada
| | - Thomas R Marotta
- Division of Interventional Neuroradiology, 10071St. Michael's Hospital, University of Toronto, Toronto, Canada
| | - Vitor Mendes Pereira
- Division of Neurosurgery, 10071St. Michael's Hospital, University of Toronto, Toronto, Canada
- Division of Interventional Neuroradiology, 10071St. Michael's Hospital, University of Toronto, Toronto, Canada
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9
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Simulation of intra-saccular devices for pre-operative device size selection: Method and validation for sizing and porosity simulation. Comput Biol Med 2022; 147:105744. [PMID: 35763930 DOI: 10.1016/j.compbiomed.2022.105744] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Revised: 05/24/2022] [Accepted: 06/11/2022] [Indexed: 11/24/2022]
Abstract
Intra-saccular devices (ID) are novel braided devices used for complex intracranial aneurysms treatment. Treatment success is associated with correct device size selection. A technique that predicts the ID size within the aneurysm before intervention will provide a powerful computational tool to aid the interventionist during device selection. We present a method to calculate the device's final height, radial expansion and porosity within the patient's anatomy, which allows assessing different device sizes before treatment takes place. The proposed sizing technique was tested in-vitro and in real patient's geometries obtained from 3DRA angiographic images of 8 unruptured aneurysms previously treated with IDs. The obtained simulated height was compared to the real height, with a mean error of less than 0.28 mm (±0.44). The porosity calculation method was tested in-vitro with an error of 0.02 (±0.022). The results of both sizing and porosity experiments resemble well measures from real patients. This methodology could be used before treatment to provide the interventionist with additional information that allows selecting the device that best fits the patient's aneurysm to be treated.
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10
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Xu J, Karmonik C, Yu Y, Lv N, Shi Z, Liu JM, Huang Q. Modeling Flow Diverters using a Porous Medium Approach: A Fast Alternative to Virtual Flow Diverter Deployment. World Neurosurg 2022; 164:e501-e508. [PMID: 35552028 DOI: 10.1016/j.wneu.2022.04.132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 04/29/2022] [Accepted: 04/29/2022] [Indexed: 11/29/2022]
Abstract
BACKGROUND The Tubridge flow diverter (FD) is a novel device aimed at reconstructing the parent artery and eliminating the aneurysm. Numerical simulations based on virtual FD deployment allow the assessment of the complex nature of aneurismal flow changes before the actual intervention but are demanding on computational resources. Here, we evaluate an alternative strategy of modeling FD effects for the Tubridge system using a porous medium. The goal of this study is to reduce demands on time and complexity of the simulation procedure for applications in clinical research. METHODS Ten patient-specific aneurysm models were reconstructed from retrospectively collected diagnostic 3D-DSA images. Virtual FDs were deployed (SolidWorks, Meshmixer) and corresponding porous medium patches were constructed at the ostium with a research CFD prototype (Siemens Healthineers, Forchheim, Germany). Hemodynamic conditions were simulated in two approaches. RESULTS Hemodynamics inside the aneurysm based on these two approaches were compared. Both approaches yielded similar results. Mean wall shear stress (WSS) and mean pressure of the aneurysmal wall correlated significantly (r=0.8, r=1.0, p-value<0.05) as did mean velocity, mean pressure at a region inside the aneurysm, at the ostium and at a cross section containing the main vertex (for velocities r=0.9; for pressures r=1.0, p-value<0.05). The use of porous medium patches reduced the preparation and simulation time together by approximately 50%. CONCLUSION Using a porous medium approach yields comparable mean values for hemodynamic alterations compared to direct virtual FD simulations. Additionally, the porous medium approach greatly reduced the modeling complexity and computation time.
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Affiliation(s)
- Jinyu Xu
- From the Department of Neurosurgery, Changhai Hospital, Second Military Medical University, Shanghai, China
| | - Christof Karmonik
- Translational Imaging Center, MRI core, Houston Methodist Research Institute, Houston TX, USA
| | - Ying Yu
- From the Department of Neurosurgery, Changhai Hospital, Second Military Medical University, Shanghai, China
| | - Nan Lv
- From the Department of Neurosurgery, Changhai Hospital, Second Military Medical University, Shanghai, China
| | - Zhaoyue Shi
- Translational Imaging Center, MRI core, Houston Methodist Research Institute, Houston TX, USA
| | - Jian-Min Liu
- From the Department of Neurosurgery, Changhai Hospital, Second Military Medical University, Shanghai, China.
| | - Qinghai Huang
- From the Department of Neurosurgery, Changhai Hospital, Second Military Medical University, Shanghai, China.
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11
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Pattern of changes in cross sectional area of arterial branches after jailing with pipeline embolization device: beyond parent neck artery patency. Clin Imaging 2022; 83:159-165. [DOI: 10.1016/j.clinimag.2021.12.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Revised: 12/18/2021] [Accepted: 12/27/2021] [Indexed: 11/17/2022]
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12
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Reorowicz P, Tyfa Z, Obidowski D, Wiśniewski K, Stefańczyk L, Jóźwik K, Levy ML. Blood flow through the fusiform aneurysm treated with the Flow Diverter stent – Numerical investigations. Biocybern Biomed Eng 2022. [DOI: 10.1016/j.bbe.2022.02.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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13
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Uchiyama Y, Fujimura S, Takao H, Suzuki T, Ishibashi T, Otani K, Karagiozov K, Fukudome K, Yamamoto H, Yamamoto M, Murayama Y. Role of patient-specific blood properties in computational fluid dynamics simulation of flow diverter deployed cerebral aneurysms. Technol Health Care 2022; 30:839-850. [PMID: 35068427 PMCID: PMC9398066 DOI: 10.3233/thc-213216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND: Hemodynamics and their clinical outcome of cerebral aneurysms treated with flow diverter (FD) stents have thus far been investigated using computational fluid dynamics (CFD) simulations. Although human blood is characterized as a non-Newtonian patientspecific fluid, non-patient-specific blood properties (PSBP) were applied in most extant studies. OBJECTIVE: To investigate the hemodynamic effects caused by PSBPs in aneurysms treated with FD stents. METHODS: We measured blood properties (density and viscosity) for 12 patients who underwent FD stent deployment. We conducted CFD simulations with the measured PSBPs and non-PSBPs quoted from previous studies. The average blood flow velocity and wall shear stress within the aneurysms were calculated and two simulation patterns were compared. RESULTS: The velocity and wall shear stress changed by 2.93% and 3.16% on average, respectively, without an FD stent deployed. Conversely, with the FD stents deployed, the change rates increased to 11.1% and 9.06% on average, respectively. CONCLUSIONS: The change in hemodynamic parameters if PSBPs are considered, may not be negligible when conducting CFD simulations of FD stent deployed aneurysms To obtain an adequate hemodynamic environment for cerebral aneurysms with FD stents deployed, it is recommended to use PSBPs for CFD simulations.
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Affiliation(s)
- Yuya Uchiyama
- Graduate School of Mechanical Engineering, Tokyo University of Science, Katsushika-ku, Tokyo, Japan
- Department of Innovation for Medical Information Technology, The Jikei University School of Medicine, Minato-ku, Tokyo, Japan
| | - Soichiro Fujimura
- Department of Innovation for Medical Information Technology, The Jikei University School of Medicine, Minato-ku, Tokyo, Japan
- Department of Mechanical Engineering, Tokyo University of Science, Katsushika-ku, Tokyo, Japan
| | - Hiroyuki Takao
- Graduate School of Mechanical Engineering, Tokyo University of Science, Katsushika-ku, Tokyo, Japan
- Department of Innovation for Medical Information Technology, The Jikei University School of Medicine, Minato-ku, Tokyo, Japan
- Department of Neurosurgery, The Jikei University School of Medicine, Minato-ku, Tokyo, Japan
| | - Takashi Suzuki
- Department of Innovation for Medical Information Technology, The Jikei University School of Medicine, Minato-ku, Tokyo, Japan
| | - Toshihiro Ishibashi
- Department of Neurosurgery, The Jikei University School of Medicine, Minato-ku, Tokyo, Japan
| | - Katharina Otani
- Department of Neurosurgery, The Jikei University School of Medicine, Minato-ku, Tokyo, Japan
- Siemens Healthcare Japan K.K., Shinagawa-ku, Tokyo, Japan
| | - Kostadin Karagiozov
- Department of Neurosurgery, The Jikei University School of Medicine, Minato-ku, Tokyo, Japan
| | - Koji Fukudome
- Department of Mechanical Engineering, Tokyo University of Science, Katsushika-ku, Tokyo, Japan
| | - Hideki Yamamoto
- Faculty of Environmental and Urban Engineering, Kansai University Fukita-shi, Osaka, Japan
| | - Makoto Yamamoto
- Department of Mechanical Engineering, Tokyo University of Science, Katsushika-ku, Tokyo, Japan
| | - Yuichi Murayama
- Department of Neurosurgery, The Jikei University School of Medicine, Minato-ku, Tokyo, Japan
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14
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Mousavi J. S. SM, Faghihi D, Sommer K, Bhurwani MMS, Patel TR, Santo B, Waqas M, Ionita C, Levy EI, Siddiqui AH, Tutino VM. Realistic computer modelling of stent retriever thrombectomy: a hybrid finite-element analysis-smoothed particle hydrodynamics model. J R Soc Interface 2021; 18:20210583. [PMID: 34905967 PMCID: PMC8672072 DOI: 10.1098/rsif.2021.0583] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Accepted: 11/22/2021] [Indexed: 01/11/2023] Open
Abstract
Stent retriever thrombectomy is a pre-eminent treatment modality for large vessel ischaemic stroke. Simulation of thrombectomy could help understand stent and clot mechanics in failed cases and provide a digital testbed for the development of new, safer devices. Here, we present a novel, in silico thrombectomy method using a hybrid finite-element analysis (FEA) and smoothed particle hydrodynamics (SPH). Inspired by its biological structure and components, the blood clot was modelled with the hybrid FEA-SPH method. The Solitaire self-expanding stent was parametrically reconstructed from micro-CT imaging and was modelled as three-dimensional finite beam elements. Our simulation encompassed all steps of mechanical thrombectomy, including stent packaging, delivery and self-expansion into the clot, and clot extraction. To test the feasibility of our method, we simulated clot extraction in simple straight vessels. This was compared against in vitro thrombectomies using the same stent, vessel geometry, and clot size and composition. Comparisons with benchtop tests indicated that our model was able to accurately simulate clot deflection and penetration of stent wires into the clot, the relative movement of the clot and stent during extraction, and clot fragmentation/embolus formation. In this study, we demonstrated that coupling FEA and SPH techniques could realistically model stent retriever thrombectomy.
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Affiliation(s)
- S. Mostafa Mousavi J. S.
- Canon Stroke and Vascular Research Center, University at Buffalo, Buffalo, NY 14203, USA
- Department of Mechanical and Aerospace Engineering, University at Buffalo, Buffalo, NY 14203, USA
| | - Danial Faghihi
- Department of Mechanical and Aerospace Engineering, University at Buffalo, Buffalo, NY 14203, USA
| | - Kelsey Sommer
- Canon Stroke and Vascular Research Center, University at Buffalo, Buffalo, NY 14203, USA
- Department of Biomedical Engineering, University at Buffalo, Buffalo, NY 14203, USA
| | - Mohammad M. S. Bhurwani
- Canon Stroke and Vascular Research Center, University at Buffalo, Buffalo, NY 14203, USA
- Department of Biomedical Engineering, University at Buffalo, Buffalo, NY 14203, USA
| | - Tatsat R. Patel
- Canon Stroke and Vascular Research Center, University at Buffalo, Buffalo, NY 14203, USA
- Department of Mechanical and Aerospace Engineering, University at Buffalo, Buffalo, NY 14203, USA
| | - Briana Santo
- Canon Stroke and Vascular Research Center, University at Buffalo, Buffalo, NY 14203, USA
- Department of Pathology and Anatomical Sciences, University at Buffalo, Buffalo, NY 14203, USA
| | - Muhammad Waqas
- Canon Stroke and Vascular Research Center, University at Buffalo, Buffalo, NY 14203, USA
- Department of Biomedical Engineering, University at Buffalo, Buffalo, NY 14203, USA
| | - Ciprian Ionita
- Canon Stroke and Vascular Research Center, University at Buffalo, Buffalo, NY 14203, USA
- Department of Biomedical Engineering, University at Buffalo, Buffalo, NY 14203, USA
| | - Elad I. Levy
- Canon Stroke and Vascular Research Center, University at Buffalo, Buffalo, NY 14203, USA
- Department of Neurosurgery, University at Buffalo, Buffalo, NY 14203, USA
| | - Adnan H. Siddiqui
- Canon Stroke and Vascular Research Center, University at Buffalo, Buffalo, NY 14203, USA
- Department of Neurosurgery, University at Buffalo, Buffalo, NY 14203, USA
| | - Vincent M. Tutino
- Canon Stroke and Vascular Research Center, University at Buffalo, Buffalo, NY 14203, USA
- Department of Mechanical and Aerospace Engineering, University at Buffalo, Buffalo, NY 14203, USA
- Department of Neurosurgery, University at Buffalo, Buffalo, NY 14203, USA
- Department of Pathology and Anatomical Sciences, University at Buffalo, Buffalo, NY 14203, USA
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15
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Liu R, Jin C, Wang L, Yang Y, Fan Y, Wang W. Simulation of stent retriever thrombectomy in acute ischemic stroke by finite element analysis. Comput Methods Biomech Biomed Engin 2021; 25:740-749. [PMID: 34792427 DOI: 10.1080/10255842.2021.1976761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Stent retriever thrombectomy has become an effective method for treating acute ischemic stroke. Successful recanalization cannot be achieved for all patients. The outcome of mechanical thrombectomy may be associated with some mechanical factors, requiring efficient tools that are able to assess the interaction between stent retrievers and clots. In this study, a simulation by finite element analysis was developed to evaluate the outcome of stent retriever thrombectomy for clots of different sizes and frictional properties. The deployment and retrieval of the stent retriever were conducted in a middle cerebral artery model. The recanalization, deformation of the clot and stent retriever and the stress induced in the clot were assessed. The results showed that higher friction could lead to failed recanalization and increased stress in the clot. The simulation method can be used to characterize the mechanical behaviour of stent retrievers and clots, offering a potential tool for the optimization of device design and the selection of surgical strategies.
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Affiliation(s)
- Ronghui Liu
- Beijing Advanced Innovation Centre for Biomedical Engineering, Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing, China.,Key Laboratory of Biomedical Engineering and Translational Medicine, Ministry of Industry and Information Technology, Research Center for Biomedical Engineering, Medical Innovation & Research Division, Chinese PLA General Hospital, Beijing, China
| | - Chang Jin
- Key Laboratory of Biomedical Engineering and Translational Medicine, Ministry of Industry and Information Technology, Research Center for Biomedical Engineering, Medical Innovation & Research Division, Chinese PLA General Hospital, Beijing, China
| | - Lizhen Wang
- Beijing Advanced Innovation Centre for Biomedical Engineering, Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing, China
| | - Yisong Yang
- Key Laboratory of Biomedical Engineering and Translational Medicine, Ministry of Industry and Information Technology, Research Center for Biomedical Engineering, Medical Innovation & Research Division, Chinese PLA General Hospital, Beijing, China
| | - Yubo Fan
- Beijing Advanced Innovation Centre for Biomedical Engineering, Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing, China
| | - Weidong Wang
- Key Laboratory of Biomedical Engineering and Translational Medicine, Ministry of Industry and Information Technology, Research Center for Biomedical Engineering, Medical Innovation & Research Division, Chinese PLA General Hospital, Beijing, China
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16
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Hadad S, Mut F, Kadirvel R, Ding YH, Kallmes D, Cebral JR. Evaluation of Outcome Prediction of Flow Diversion for Intracranial Aneurysms. AJNR Am J Neuroradiol 2021; 42:1973-1978. [PMID: 34446459 DOI: 10.3174/ajnr.a7263] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Accepted: 06/10/2021] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Identifying and predicting which aneurysms are likely to quickly occlude and which ones are likely to remain open following treatment with flow-diverting devices is important to develop optimal patient management strategies. The purpose of this study was to evaluate predictions based on computational fluid dynamics models using the elastase rabbit aneurysm model. MATERIALS AND METHODS A series of 13 aneurysms created in rabbits were treated with flow diverters, and outcomes were angiographically assessed at 8 weeks' follow-up. Computational fluid dynamics models were constructed from pretreatment 3D rotational angiograms and Doppler ultrasound flow velocity measurements. Postimplantation mean aneurysm inflow rate and flow velocity were used to prospectively predict aneurysm occlusion blinded to the actual outcomes. Specifically, if both variables were below their corresponding thresholds, fast occlusion was predicted, while if one of them was above the threshold, slow or incomplete occlusion was predicted. RESULTS Of the 13 aneurysms included, 8 were incompletely occluded 8 weeks after treatment, and 5 were completely occluded. A total of 10 computational fluid dynamics-based predictions agreed with the angiographic outcome, reaching 77% accuracy, 80% sensitivity, and 75% specificity. Posttreatment mean velocity alone was able to achieve the same predictive power as the combination of inflow rate and velocity. CONCLUSIONS Subject-specific computational fluid dynamics models of the hemodynamic conditions created immediately after implantation of flow-diverting devices in experimental aneurysms created in rabbits are capable of prospectively predicting, with a reasonable accuracy, which aneurysms will completely occlude and which ones will remain incompletely occluded.
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Affiliation(s)
- S Hadad
- From the Departments of Bioengineering and Mechanical Engineering (S.H., F.M., J.R.C.), George Mason University, Fairfax, Virginia
| | - F Mut
- From the Departments of Bioengineering and Mechanical Engineering (S.H., F.M., J.R.C.), George Mason University, Fairfax, Virginia
| | - R Kadirvel
- Department of Interventional Neuroradiology (R.K., Y.-H.D., D.K.), Mayo Clinic, Rochester, Minnesota
| | - Y-H Ding
- Department of Interventional Neuroradiology (R.K., Y.-H.D., D.K.), Mayo Clinic, Rochester, Minnesota
| | - D Kallmes
- Department of Interventional Neuroradiology (R.K., Y.-H.D., D.K.), Mayo Clinic, Rochester, Minnesota
| | - J R Cebral
- From the Departments of Bioengineering and Mechanical Engineering (S.H., F.M., J.R.C.), George Mason University, Fairfax, Virginia
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17
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Hemodynamic Investigation of the Effectiveness of a Two Overlapping Flow Diverter Configuration for Cerebral Aneurysm Treatment. Bioengineering (Basel) 2021; 8:bioengineering8100143. [PMID: 34677216 PMCID: PMC8533189 DOI: 10.3390/bioengineering8100143] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Revised: 10/12/2021] [Accepted: 10/12/2021] [Indexed: 11/29/2022] Open
Abstract
Flow diverters (FDs) are widely employed as endovascular treatment devices for large or wide-neck cerebral aneurysms. Occasionally, overlapped FDs are deployed to enhance the flow diversion effect. In this study, we investigated the hemodynamics of overlapping FDs via computational fluid dynamics (CFD) simulations. We reproduced the arterial geometry of a patient who had experienced the deployment of two overlapping FDs. We utilized two stent patterns, namely the patterns for one FD and two overlapping FDs. We calculated the velocity, mass flow rate, wall shear stress, and pressure loss coefficient as well as their change rates for each pattern relative to the no-FD pattern results. The CFD simulation results indicated that the characteristics of the blood flow inside the aneurysm were minimally affected by the deployment of a single FD; in contrast, the overlapping FD pattern results revealed significant changes in the flow. Further, the velocity at an inspection plane within the aneurysm sac decreased by up to 92.2% and 31.0% in the cases of the overlapping and single FD patterns, respectively, relative to the no-FD pattern. The simulations successfully reproduced the hemodynamics, and the qualitative and quantitative investigations are meaningful with regard to the clinical outcomes of overlapped FD deployment.
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18
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Lamooki SR, Tutino VM, Paliwal N, Damiano RJ, Waqas M, Nagesh SSV, Rajabzadeh-Oghaz H, Vakharia K, Siddiqui AH, Meng H. Evaluation of Two Fast Virtual Stenting Algorithms for Intracranial Aneurysm Flow Diversion. Curr Neurovasc Res 2021; 17:58-70. [PMID: 31987021 DOI: 10.2174/1567202617666200120141608] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Revised: 11/13/2019] [Accepted: 11/25/2019] [Indexed: 11/22/2022]
Abstract
BACKGROUND Endovascular treatment of intracranial aneurysms (IAs) by flow diverter (FD) stents depends on flow modification. Patient-specific modeling of FD deployment and computational fluid dynamics (CFD) could enable a priori endovascular strategy optimization. We developed a fast, simplistic, expansion-free balls-weeping algorithm to model FDs in patientspecific aneurysm geometry. However, since such strong simplification could result in less accurate simulations, we also developed a fast virtual stenting workflow (VSW) that explicitly models stent expansion using pseudo-physical forces. METHODS To test which of these two fast algorithms more accurately simulates real FDs, we applied them to virtually treat three representative patient-specific IAs. We deployed Pipeline Embolization Device into 3 patient-specific silicone aneurysm phantoms and simulated the treatments using both balls-weeping and VSW algorithms in computational aneurysm models. We then compared the virtually deployed FD stents against experimental results in terms of geometry and post-treatment flow fields. For stent geometry, we evaluated gross configurations and porosity. For post-treatment aneurysmal flow, we compared CFD results against experimental measurements by particle image velocimetry. RESULTS We found that VSW created more realistic FD deployments than balls-weeping in terms of stent geometry, porosity and pore density. In particular, balls-weeping produced unrealistic FD bulging at the aneurysm neck, and this artifact drastically increased with neck size. Both FD deployment methods resulted in similar flow patterns, but the VSW had less error in flow velocity and inflow rate. CONCLUSION In conclusion, modeling stent expansion is critical for preventing unrealistic bulging effects and thus should be considered in virtual FD deployment algorithms. Also endowed with its high computational efficiency and superior accuracy, the VSW algorithm is a better candidate for implementation into a bedside clinical tool for FD deployment simulation.
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Affiliation(s)
- Saeb R Lamooki
- Canon Stroke and Vascular Research Center, University at Buffalo, Buffalo, NY, United States.,Department of Mechanical & Aerospace Engineering, University at Buffalo, Buffalo, NY, United States
| | - Vincent M Tutino
- Canon Stroke and Vascular Research Center, University at Buffalo, Buffalo, NY, United States.,Department of Biomedical Engineering, University at Buffalo, Buffalo, NY, United States.,Department of Neurosurgery, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, United States.,Department of Pathology and Anatomical Sciences, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, United States
| | - Nikhil Paliwal
- Canon Stroke and Vascular Research Center, University at Buffalo, Buffalo, NY, United States.,Department of Mechanical & Aerospace Engineering, University at Buffalo, Buffalo, NY, United States
| | - Robert J Damiano
- Canon Stroke and Vascular Research Center, University at Buffalo, Buffalo, NY, United States.,Department of Mechanical & Aerospace Engineering, University at Buffalo, Buffalo, NY, United States
| | - Muhammad Waqas
- Canon Stroke and Vascular Research Center, University at Buffalo, Buffalo, NY, United States.,Department of Neurosurgery, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, United States
| | - Setlur S V Nagesh
- Canon Stroke and Vascular Research Center, University at Buffalo, Buffalo, NY, United States.,Department of Neurosurgery, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, United States.,Department of Radiology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, United States
| | - Hamidreza Rajabzadeh-Oghaz
- Canon Stroke and Vascular Research Center, University at Buffalo, Buffalo, NY, United States.,Department of Mechanical & Aerospace Engineering, University at Buffalo, Buffalo, NY, United States
| | - Kunal Vakharia
- Department of Neurosurgery, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, United States
| | - Adnan H Siddiqui
- Canon Stroke and Vascular Research Center, University at Buffalo, Buffalo, NY, United States.,Department of Neurosurgery, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, United States.,Department of Neurology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, United States
| | - Hui Meng
- Canon Stroke and Vascular Research Center, University at Buffalo, Buffalo, NY, United States.,Department of Mechanical & Aerospace Engineering, University at Buffalo, Buffalo, NY, United States.,Department of Biomedical Engineering, University at Buffalo, Buffalo, NY, United States.,Department of Neurosurgery, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, United States
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19
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Dazeo N, Muñoz R, Narata AP, Fernandez H, Larrabide I. Intra-saccular device modeling for treatment planning of intracranial aneurysms: from morphology to hemodynamics. Int J Comput Assist Radiol Surg 2021; 16:1663-1673. [PMID: 34195929 DOI: 10.1007/s11548-021-02427-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Accepted: 05/28/2021] [Indexed: 10/21/2022]
Abstract
MOTIVATION Intra-saccular devices (ID), developed for the treatment of bifurcation aneurysms, offer new alternatives for treating complex terminal and bifurcation aneurysms. In this work, a complete workflow going from medical images to post-treatment CFD analysis is described and used in the assessment of a concrete clinical problem. MATERIALS AND METHODS Two different intra-saccular device sizes were virtually implanted in 3D models of the patient vasculature using the ID-Fit method. After deployment, the local porosity at the closed end of the device in contact with the blood flow was computed. This porosity was then used to produce a CFD porous medium model of the device. Velocities and wall shear stress were assessed for each model. RESULTS Six patients treated with intra-saccular devices were included in this work. For each case, 2 different device sizes were virtually implanted and 3 CFD simulations were performed: after deployment simulation with each size and before deployment simulation (untreated). A visible reduction in velocities was observed after device implantation. Velocity and WSS reduction was statistically significant (K-S statistics, [Formula: see text]). CONCLUSIONS Placement of different device size can lead to a partial filling of the aneurysm, either at the dome or at the neck, depending on the particular positioning by the interventionist. The methodology used in this work can have a strong clinical impact, since it provides additional information in the process of device selection using preoperative data.
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Affiliation(s)
- Nicolás Dazeo
- Instituto Pladema - CONICET, Universidad Nacional del Centro de la Provincia de Buenos Aires, Tandil, Argentina.
| | - Romina Muñoz
- Instituto Pladema - CONICET, Universidad Nacional del Centro de la Provincia de Buenos Aires, Tandil, Argentina
| | - Ana Paula Narata
- Neuroradiology Department, University Hospital of Southampton, Southampton, UK
| | | | - Ignacio Larrabide
- Instituto Pladema - CONICET, Universidad Nacional del Centro de la Provincia de Buenos Aires, Tandil, Argentina.,Galgo Medical S.L., Barcelona, Spain
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20
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Pan C, Han Y, Lu J. Structural Design of Vascular Stents: A Review. MICROMACHINES 2021; 12:mi12070770. [PMID: 34210099 PMCID: PMC8305143 DOI: 10.3390/mi12070770] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Revised: 06/16/2021] [Accepted: 06/24/2021] [Indexed: 11/18/2022]
Abstract
Percutaneous Coronary Intervention (PCI) is currently the most conventional and effective method for clinically treating cardiovascular diseases such as atherosclerosis. Stent implantation, as one of the ways of PCI in the treatment of coronary artery diseases, has become a hot spot in scientific research with more and more patients suffering from cardiovascular diseases. However, vascular stent implanted into vessels of patients often causes complications such as In-Stent Restenosis (ISR). The vascular stent is one of the sophisticated medical devices, a reasonable structure of stent can effectively reduce the complications. In this paper, we introduce the evolution, performance evaluation standards, delivery and deployment, and manufacturing methods of vascular stents. Based on a large number of literature pieces, this paper focuses on designing structures of vascular stents in terms of “bridge (or link)” type, representative volume unit (RVE)/representative unit cell (RUC), and patient-specific stent. Finally, this paper gives an outlook on the future development of designing vascular stents.
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Affiliation(s)
- Chen Pan
- School of Mechanical Engineering, Beijing Institute of Technology, Zhongguancun South Street No. 5, Haidian District, Beijing 100081, China; (C.P.); (J.L.)
- Institute of Engineering Medicine, Beijing Institute of Technology, Zhongguancun South Street No. 5, Haidian District, Beijing 100081, China
| | - Yafeng Han
- School of Mechanical Engineering, Beijing Institute of Technology, Zhongguancun South Street No. 5, Haidian District, Beijing 100081, China; (C.P.); (J.L.)
- Correspondence:
| | - Jiping Lu
- School of Mechanical Engineering, Beijing Institute of Technology, Zhongguancun South Street No. 5, Haidian District, Beijing 100081, China; (C.P.); (J.L.)
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21
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Fast virtual coiling algorithm for intracranial aneurysms using pre-shape path planning. Comput Biol Med 2021; 134:104496. [PMID: 34077817 DOI: 10.1016/j.compbiomed.2021.104496] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Revised: 05/11/2021] [Accepted: 05/12/2021] [Indexed: 09/30/2022]
Abstract
To aid in predicting and improving treatment outcome of endovascular coiling of intracranial aneurysms, simulation of patient-specific coil deployment should be both accurate and fast. We developed a fast virtual coiling algorithm called Pre-shape Path Planning (P3). It captures the mechanical propensity of a released coil to restore its pre-shape for bending energy minimization, producing coils without unrealistic kinks and bends. A coil is discretized into finite-length segments and extruded from the delivery catheter segment-by-segment following a generic coil pre-shape. With the release of each segment, coil-wall and coil-coil collisions are detected and resolved. Modeling of each case took seconds to minutes. To test the algorithm, we evaluated its output against the literature, experiments, and patient angiograms. The periphery-to-core ratio of coils deployed by P3 decreased with increasing coil packing density, consistent with observations in the literature. Coils deployed by P3 compared well with in vitro experiments, free from unphysical kinks and loops that arose from previous virtual coiling algorithms. Simulations of coiling in four patient-specific aneurysms agreed well with the patient angiograms. To test the influence of coil pre-shape on P3, we performed hemodynamic simulations in aneurysms with coils deployed by P3 using the generic pre-shape, P3 using a coil-specific pre-shape, and full finite-element-method simulation. We found that the generic pre-shape was sufficient to produce results comparable to virtual coiling by finite element modeling. Based on these findings, P3 can rapidly simulate coiling in patient-specific aneurysms with good accuracy and is thus a potential candidate for clinical treatment planning.
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22
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Giuliodori A, Hernández JA, Fernandez-Sanchez D, Galve I, Soudah E. Numerical modeling of bare and polymer-covered braided stents using torsional and tensile springs connectors. J Biomech 2021; 123:110459. [PMID: 34022531 DOI: 10.1016/j.jbiomech.2021.110459] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Revised: 04/12/2021] [Accepted: 04/13/2021] [Indexed: 09/30/2022]
Abstract
Computational modeling of braided stents using the finite element (FE) method has become an essential tool in the design and development of these medical devices. One of the most challenging issues in such a task is representing in an accurate manner the interaction between the interlacing wires. With the goal of achieving a compromise between accuracy and computational affordability, we propose a new approach consisting in using 1D FE formulations equipped with torsional springs at the crossover points of the wires. In the case of covered braided stents, the model is enriched with a set of tensile springs (defined in the longitudinal direction), aimed at capturing the stiffening effect of the polymeric membrane. The predictive capabilities of the proposed model are evaluated using data of our own experimental tests, as well as data from other tests in the literature. The simulations demonstrate that the proposed model is able to predict the (markedly nonlinear) behavior of stents when subjected to radial and axial cycle loads, with errors at the end of the compression stage ranging from 0.5% to 10% in all cases.
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Affiliation(s)
- Agustina Giuliodori
- Centre Internacional de Métodes Numérics en Enginerya, CIMNE, Barcelona, Spain; Universitat Politécnica de Catalunya, UPC, Barcelona, Spain.
| | - Joaquín A Hernández
- Centre Internacional de Métodes Numérics en Enginerya, CIMNE, Barcelona, Spain; E.S. d'Enginyeries Industrial, Aeroespacial i Audiovisual de Terrassa, Technical University of Catalonia, C/ Colom, 11, Terrassa 08222, Spain
| | | | | | - Eduardo Soudah
- Centre Internacional de Métodes Numérics en Enginerya, CIMNE, Barcelona, Spain; Universitat Politécnica de Catalunya, UPC, Barcelona, Spain
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23
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Zaccaria A, Pennati G, Petrini L. Analytical methods for braided stents design and comparison with FEA. J Mech Behav Biomed Mater 2021; 119:104560. [PMID: 33930655 DOI: 10.1016/j.jmbbm.2021.104560] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Revised: 04/13/2021] [Accepted: 04/19/2021] [Indexed: 01/06/2023]
Abstract
Braiding technology is nowadays commonly adopted to build stent-like devices. Indeed, these endoprostheses, thanks to their typical great flexibility and kinking resistance, find several applications in mini-invasive treatments, involving but not limiting to the cardiovascular field. The design process usually involves many efforts and long trial and error processes before identifying the best combination of manufacturing parameters. This paper aims to provide analytical tools to support the design and optimization phases: the developed equations, based on few geometrical parameters commonly used for describing braided stents and material stiffness, are easily implementable in a worksheet and allow predicting the radial rigidity of braided stents, also involving complex features such as multiple twists and looped ends, and the diameter variation range. Finite element simulations, previously validated with respect to experimental tests, were used as a comparator to prove the reliability of the analytical results. The illustrated tools can assess the impact of each selected parameter modification and are intended to guide the optimal selection of geometrical and mechanical stent proprieties to obtain the desired radial rigidity, deliverability (minimum diameter), and, if forming processes are planned to modify the shape of the stent, the required diameter variations (maximum and minimum diameters).
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Affiliation(s)
- Alissa Zaccaria
- LaBS, Dept. of Chemistry, Materials and Chemical Engineering, Politecnico di Milano, Milan, Italy; Consorzio Intellimech, Bergamo, Italy.
| | - Giancarlo Pennati
- LaBS, Dept. of Chemistry, Materials and Chemical Engineering, Politecnico di Milano, Milan, Italy.
| | - Lorenza Petrini
- Dept. of Civil and Environmental Engineering, Politecnico di Milano, Milan, Italy.
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24
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Zhang H, Li L, Miao F, Yu J, Zhou B, Pan Y. Computational fluid dynamics analysis of intracranial aneurysms treated with flow diverters: A case report. Neurochirurgie 2021; 68:235-238. [PMID: 33771614 DOI: 10.1016/j.neuchi.2021.03.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Revised: 02/05/2021] [Accepted: 03/06/2021] [Indexed: 01/08/2023]
Abstract
INTRODUCTION Intracranial aneurysms (IAs) are localized dilatations of intracranial arteries due to weaknesses of the endothelial layer. IAs may be treated by flow diverters (FDs), alternatively to stents and coils combination. FD is a method for the treatment of IAs especially for large, wide-necked or fusiform aneurysms. In this case report, we described a 65-year-old woman with IA who were treated by FD. CASE PRESENTATION A 65-year-old woman was diagnosed with a giant aneurysm at the posterior inferior cerebellar artery segment of the left internal carotid artery. Then based on the computed tomography data of this woman, aneurysm vascular stent model was constructed before and after FD, and internal pressure, velocity, wall shear stress (WSS) of aneurysms were determined by CFD analysis. Standard boundary conditions were applied. It was found that a single FD stent and double FD stents decreased the blood flow and WSS of aneurysm. The effect of single FD stent+30% filling on blood flow was more obvious, but the aneurysm rupture was caused by excessive coil packing. So, a single stent+10% coil packing rate was the best option for treating aneurysms. CONCLUSIONS CFD analysis for flow velocity and WSS have protection on aneurysms.
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Affiliation(s)
- H Zhang
- Department of Neurosurgery, Lanzhou University Second Hospital, 80, Cuiyingmen Road, Chengguan District, 730030 Lanzhou City, Gansu Province, China
| | - L Li
- School of Clinical Medicine, Gansu University of Chinese Medicine, 730030 Lanzhou, China
| | - F Miao
- Department of Neurosurgery, Zhangye People's Hospital Affiliated to Hexi University, 734000 Zhangye, China
| | - J Yu
- College of Petroleum and Chemical Engineering, Lanzhou University of Technology, 730050 Lanzhou, China
| | - B Zhou
- Department of Neurosurgery, Lanzhou University Second Hospital, 80, Cuiyingmen Road, Chengguan District, 730030 Lanzhou City, Gansu Province, China
| | - Y Pan
- Department of Neurosurgery, Lanzhou University Second Hospital, 80, Cuiyingmen Road, Chengguan District, 730030 Lanzhou City, Gansu Province, China.
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McKenna CG, Vaughan TJ. A finite element investigation on design parameters of bare and polymer-covered self-expanding wire braided stents. J Mech Behav Biomed Mater 2021; 115:104305. [PMID: 33454463 DOI: 10.1016/j.jmbbm.2020.104305] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 12/02/2020] [Accepted: 12/29/2020] [Indexed: 02/07/2023]
Abstract
Self-expanding covered braided stents are routinely used across a diverse range of clinical applications, but few computational studies have attempted to replicate their complex behaviour. In this study, a computational framework was developed to predict the functional performance of bare and covered self-expanding wire braided stents, with a systematic evaluation on the effect of various braid and cover parameters presented. Simulated radial force and kink deformation tests show good agreement to experimental data for covered braided stents across a range of braid angles and cover thicknesses. Our results demonstrate that braid angle is a key governing parameter that dictates the radial and kink performance of both bare-metal and covered wire braided stents. It was also demonstrated that addition of a polymeric cover to a wire braided stent causes a stiffer radial response across all braid angles, particularly when thicker and/or stiffer covering systems were considered. This study represents the first experimentally-validated computational model for covered wire braided stent systems and has excellent potential to be used in future design of these devices for a range of applications.
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Affiliation(s)
- Ciara G McKenna
- Biomechanics Research Centre (BioMEC), Biomedical Engineering, School of Engineering, College of Science and Engineering, National University of Ireland Galway, Galway, Ireland
| | - Ted J Vaughan
- Biomechanics Research Centre (BioMEC), Biomedical Engineering, School of Engineering, College of Science and Engineering, National University of Ireland Galway, Galway, Ireland.
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Maragkos GA, Dmytriw AA, Salem MM, Tutino VM, Meng H, Cognard C, Machi P, Krings T, Mendes Pereira V. Overview of Different Flow Diverters and Flow Dynamics. Neurosurgery 2020; 86:S21-S34. [PMID: 31838536 DOI: 10.1093/neuros/nyz323] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Accepted: 04/30/2019] [Indexed: 12/16/2022] Open
Abstract
Over the past decade, flow diverter technology for endocranial aneurysms has seen rapid evolution, with the development of new devices quickly outpacing the clinical evidence base. However, flow diversion has not yet been directly compared to surgical aneurysm clipping or other endovascular procedures. The oldest and most well-studied device is the Pipeline Embolization Device (PED; Medtronic), recently transitioned to the Pipeline Flex (Medtronic), which still has sparse data regarding outcomes. To date, other flow diverting devices have not been shown to outperform the PED, although information comes primarily from retrospective studies with short follow-up, which are not always comparable. Because of this lack of high-quality outcome data, no reliable recommendations can be made for choosing among flow diversion devices yet. Moreover, the decision to proceed with flow diversion should be individualized to each patient. In this work, we wish to provide a comprehensive overview of the technical specifications of all flow diverter devices currently available, accompanied by a succinct description of the evidence base surrounding each device.
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Affiliation(s)
- Georgios A Maragkos
- Neurosurgical Service, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
| | - Adam A Dmytriw
- Neurosurgical Service, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts.,Department of Medical Imaging, Toronto Western Hospital and St. Michael's Hospital, University of Toronto, Toronto, Canada
| | - Mohamed M Salem
- Neurosurgical Service, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
| | - Vincent M Tutino
- Canon Stroke and Vascular Research Center, University at Buffalo, Clinical and Translational Research Center, New York
| | - Hui Meng
- Canon Stroke and Vascular Research Center, University at Buffalo, Clinical and Translational Research Center, New York
| | - Christophe Cognard
- Department of Diagnostic and Therapeutic Neuroradiology, Centre Hopitalier de Toulouse, Toulouse, France
| | - Paolo Machi
- Department of Neuroradiology, Montpellier University Hospital, Montpellier, France
| | - Timo Krings
- Department of Medical Imaging, Toronto Western Hospital and St. Michael's Hospital, University of Toronto, Toronto, Canada
| | - Vitor Mendes Pereira
- Department of Medical Imaging, Toronto Western Hospital and St. Michael's Hospital, University of Toronto, Toronto, Canada
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Zaccaria A, Danielli F, Gasparotti E, Fanni BM, Celi S, Pennati G, Petrini L. Left atrial appendage occlusion device: Development and validation of a finite element model. Med Eng Phys 2020; 82:104-118. [DOI: 10.1016/j.medengphy.2020.05.019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2020] [Revised: 05/17/2020] [Accepted: 05/25/2020] [Indexed: 11/26/2022]
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Zaccaria A, Migliavacca F, Pennati G, Petrini L. Modeling of braided stents: Comparison of geometry reconstruction and contact strategies. J Biomech 2020; 107:109841. [DOI: 10.1016/j.jbiomech.2020.109841] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Revised: 04/21/2020] [Accepted: 05/05/2020] [Indexed: 11/25/2022]
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Závodszky G, Csippa B, Paál G, Szikora I. A novel virtual flow diverter implantation method with realistic deployment mechanics and validated force response. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2020; 36:e3340. [PMID: 32279440 PMCID: PMC7317397 DOI: 10.1002/cnm.3340] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Revised: 04/01/2020] [Accepted: 04/02/2020] [Indexed: 06/11/2023]
Abstract
Virtual flow diverter deployment techniques underwent significant development during the last couple of years. Each existing technique displays advantageous features, as well as significant limitations. One common drawback is the lack of quantitative validation of the mechanics of the device. In the following work, we present a new spring-mass-based method with validated mechanical responses that combines many of the useful capabilities of previous techniques. The structure of the virtual braids naturally incorporates the axial length changes as a function of the local expansion diameter. The force response of the model was calibrated using the measured response of real FDs. The mechanics of the model allows to replicate the expansion process during deployment, including additional effects such as the push-pull technique that is required for the deployment of braided FDs to achieve full opening and proper wall apposition. Furthermore, it is a computationally highly efficient solution that requires little pre-processing and has a run-time of a few seconds on a general laptop and thus allows for exploratory analyses. The model was applied in a patient-specific geometry, where corresponding accurate control measurements in a 3D-printed model were also available. The analysis shows the effects of FD oversizing and push-pull application on the radial expansion, surface density, and on the wall contact pressure.
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Affiliation(s)
- Gábor Závodszky
- Computational Science Lab, Faculty of Science, Institute for InformaticsUniversity of AmsterdamAmsterdamNetherlands
- Department of Hydrodynamic SystemsBudapest University of Technology and EconomicsBudapestHungary
| | - Benjámin Csippa
- Department of Hydrodynamic SystemsBudapest University of Technology and EconomicsBudapestHungary
| | - György Paál
- Department of Hydrodynamic SystemsBudapest University of Technology and EconomicsBudapestHungary
| | - István Szikora
- Department of NeurointerventionsNational Institute of Clinical NeurosciencesBudapestHungary
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Cai Y, Meng Z, Jiang Y, Zhang X, Yang X, Wang S. Finite element modeling and simulation of the implantation of braided stent to treat cerebral aneurysm. MEDICINE IN NOVEL TECHNOLOGY AND DEVICES 2020. [DOI: 10.1016/j.medntd.2020.100031] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
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Piergallini L, Cagnazzo F, Conte G, Dargazanli C, Derraz I, Lefevre PH, Gascou G, Mantilla D, Riquelme C, Bonafe A, Costalat V. Virtual simulation with Sim&Size software for Pipeline Flex Embolization: evaluation of the technical and clinical impact. J Neurointerv Surg 2020; 12:968-973. [DOI: 10.1136/neurintsurg-2020-015813] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Revised: 02/11/2020] [Accepted: 02/19/2020] [Indexed: 12/26/2022]
Abstract
IntroductionDuring flow diversion, the choice of the length, diameter, and location of the deployed stent are critical for the success of the procedure. Sim&Size software, based on the three-dimensional rotational angiography (3D-RA) acquisition, simulates the release of the stent, suggesting optimal sizing, and displaying the degree of the wall apposition.ObjectiveTo demonstrate technical and clinical impacts of the Sim&Size simulation during treatment with the Pipeline Flex Embolization Device.MethodsConsecutive patients who underwent aneurysm embolization with Pipeline at our department were retrospectively enrolled (January 2015–December 2017) and divided into two groups: treated with and without simulation. Through univariate and multivariate models, we evaluated: (1) rate of corrective intervention for non-optimal stent placement, (2) duration of intervention, (3) radiation dose, and (4) stent length.Results189 patients, 95 (50.2%) without and 94 (49.7%) with software assistance were analyzed. Age, sex, comorbidities, aneurysm characteristics, and operator’s experience were comparable among the two groups. Procedures performed with the software had a lower rate of corrective intervention (9% vs 20%, p=0.036), a shorter intervention duration (46 min vs 52 min, p=0.002), a lower median radiation dose (1150 mGy vs 1558 mGy, p<0.001), and a shorter stent length (14 mm vs 16 mm, p<0.001).ConclusionsIn our experience, the use of the virtual simulation during Pipeline treatment significantly reduced the need for corrective intervention, the procedural time, the radiation dose, and the length of the stent.
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Acuna A, Berman AG, Damen FW, Meyers BA, Adelsperger AR, Bayer KC, Brindise MC, Bungart B, Kiel AM, Morrison RA, Muskat JC, Wasilczuk KM, Wen Y, Zhang J, Zito P, Goergen CJ. Computational Fluid Dynamics of Vascular Disease in Animal Models. J Biomech Eng 2019; 140:2676341. [PMID: 29570754 DOI: 10.1115/1.4039678] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Indexed: 12/19/2022]
Abstract
Recent applications of computational fluid dynamics (CFD) applied to the cardiovascular system have demonstrated its power in investigating the impact of hemodynamics on disease initiation, progression, and treatment outcomes. Flow metrics such as pressure distributions, wall shear stresses (WSS), and blood velocity profiles can be quantified to provide insight into observed pathologies, assist with surgical planning, or even predict disease progression. While numerous studies have performed simulations on clinical human patient data, it often lacks prediagnosis information and can be subject to large intersubject variability, limiting the generalizability of findings. Thus, animal models are often used to identify and manipulate specific factors contributing to vascular disease because they provide a more controlled environment. In this review, we explore the use of CFD in animal models in recent studies to investigate the initiating mechanisms, progression, and intervention effects of various vascular diseases. The first section provides a brief overview of the CFD theory and tools that are commonly used to study blood flow. The following sections are separated by anatomical region, with the abdominal, thoracic, and cerebral areas specifically highlighted. We discuss the associated benefits and obstacles to performing CFD modeling in each location. Finally, we highlight animal CFD studies focusing on common surgical treatments, including arteriovenous fistulas (AVF) and pulmonary artery grafts. The studies included in this review demonstrate the value of combining CFD with animal imaging and should encourage further research to optimize and expand upon these techniques for the study of vascular disease.
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Affiliation(s)
- Andrea Acuna
- Weldon School of Biomedical Engineering, Purdue University, 206 S. Martin Jischke Drive, West Lafayette, IN 47907 e-mail:
| | - Alycia G Berman
- Weldon School of Biomedical Engineering, Purdue University, 206 S. Martin Jischke Drive, West Lafayette, IN 47907 e-mail:
| | - Frederick W Damen
- Weldon School of Biomedical Engineering, Purdue University, 206 S. Martin Jischke Drive, West Lafayette, IN 47907 e-mail:
| | - Brett A Meyers
- School of Mechanical Engineering, Purdue University, 585 Purdue Mall, West Lafayette, IN 47907 e-mail:
| | - Amelia R Adelsperger
- Weldon School of Biomedical Engineering, Purdue University, 206 S. Martin Jischke Drive, West Lafayette, IN 47907 e-mail:
| | - Kelsey C Bayer
- Weldon School of Biomedical Engineering, Purdue University, 206 S. Martin Jischke Drive, West Lafayette, IN 47907 e-mail:
| | - Melissa C Brindise
- School of Mechanical Engineering, Purdue University, 585 Purdue Mall, West Lafayette, IN 47907 e-mail:
| | - Brittani Bungart
- Weldon School of Biomedical Engineering, Purdue University, 206 S. Martin Jischke Drive, West Lafayette, IN 47907 e-mail:
| | - Alexander M Kiel
- Weldon School of Biomedical Engineering, Purdue University, 206 S. Martin Jischke Drive, West Lafayette, IN 47907 e-mail:
| | - Rachel A Morrison
- Weldon School of Biomedical Engineering, Purdue University, 206 S. Martin Jischke Drive, West Lafayette, IN 47907 e-mail:
| | - Joseph C Muskat
- Weldon School of Biomedical Engineering, Purdue University, 206 S. Martin Jischke Drive, West Lafayette, IN 47907 e-mail:
| | - Kelsey M Wasilczuk
- Weldon School of Biomedical Engineering, Purdue University, 206 S. Martin Jischke Drive, West Lafayette, IN 47907 e-mail:
| | - Yi Wen
- Department of Agricultural and Biological Engineering, Purdue University, 225 South University Street, West Lafayette, IN 47907 e-mail:
| | - Jiacheng Zhang
- School of Mechanical Engineering, Purdue University, 585 Purdue Mall, West Lafayette, IN 47907 e-mail:
| | - Patrick Zito
- Weldon School of Biomedical Engineering, Purdue University, 206 S. Martin Jischke Drive, West Lafayette, IN 47907 e-mail:
| | - Craig J Goergen
- ASME Membership Bioengineering Division, Weldon School of Biomedical Engineering, Purdue University, 206 S. Martin Jischke Drive, West Lafayette, IN 47907 e-mail:
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Kelly N, McGrath DJ, Sweeney CA, Kurtenbach K, Grogan JA, Jockenhoevel S, O’Brien BJ, Bruzzi M, McHugh PE. Comparison of computational modelling techniques for braided stent analysis. Comput Methods Biomech Biomed Engin 2019; 22:1334-1344. [DOI: 10.1080/10255842.2019.1663414] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Nicola Kelly
- Biomechanics Research Centre (BioMEC), Biomedical Engineering, College of Engineering and Informatics, National University of Ireland Galway, Galway, Ireland
| | - Donnacha J. McGrath
- Biomechanics Research Centre (BioMEC), Biomedical Engineering, College of Engineering and Informatics, National University of Ireland Galway, Galway, Ireland
| | - Caoimhe A. Sweeney
- Biomechanics Research Centre (BioMEC), Biomedical Engineering, College of Engineering and Informatics, National University of Ireland Galway, Galway, Ireland
| | - Kathrin Kurtenbach
- Institute for Textile Engineering, RWTH Aachen University, Aachen, Germany
| | - James A. Grogan
- Biomechanics Research Centre (BioMEC), Biomedical Engineering, College of Engineering and Informatics, National University of Ireland Galway, Galway, Ireland
| | - Stefan Jockenhoevel
- Department of Biohybrid and Medical Textiles (BioTex), AME – Institute of Applied Medical Engineering, Helmholtz Institute, RWTH Aachen University, Aachen, Germany
| | - Barry J. O’Brien
- Biomechanics Research Centre (BioMEC), Biomedical Engineering, College of Engineering and Informatics, National University of Ireland Galway, Galway, Ireland
| | - Mark Bruzzi
- Biomechanics Research Centre (BioMEC), Biomedical Engineering, College of Engineering and Informatics, National University of Ireland Galway, Galway, Ireland
| | - Peter E. McHugh
- Biomechanics Research Centre (BioMEC), Biomedical Engineering, College of Engineering and Informatics, National University of Ireland Galway, Galway, Ireland
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Computational methods applied to analyze the hemodynamic effects of flow-diverter devices in the treatment of cerebral aneurysms: Current status and future directions. MEDICINE IN NOVEL TECHNOLOGY AND DEVICES 2019. [DOI: 10.1016/j.medntd.2019.100018] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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Kellermann R, Serowy S, Beuing O, Skalej M. Deployment of flow diverter devices: prediction of foreshortening and validation of the simulation in 18 clinical cases. Neuroradiology 2019; 61:1319-1326. [PMID: 31473786 DOI: 10.1007/s00234-019-02287-w] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Accepted: 08/26/2019] [Indexed: 11/28/2022]
Abstract
PURPOSE Flow diverter (FD) devices show severe shortening during deployment in dependency of the vessel geometry. Valid information regarding the geometry of the targeted vessel is therefore mandatory for correct device selection, and to avoid complications. But the geometry of diseased tortuous intracranial vessels cannot be measured accurately with standard methods. The goal of this study is to prove the accuracy of a novel virtual stenting method in prediction of the behavior of a FD in an individual vessel geometry. METHODS We applied a virtual stenting method on angiographic 3D imaging data of the specific vasculature of patients, who underwent FD treatment. The planning tool analyzes the local vessel morphology and deploys the FD virtually. We measured in 18 cases the difference between simulated FD length and real FD length after treatment in a landmark-based registration of pre-/post-interventional 3D angiographic datasets. RESULTS The mean value of length deviation of the virtual FD was 2.2 mm (SD ± 1.9 mm) equaling 9.5% (SD ± 8.2%). Underestimated cases present lower deviations compared with overestimated FDs. Flow diverter cases with a nominal device length of 20 mm had the highest prediction accuracy. CONCLUSION The results suggest that the virtual stenting method used in this study is capable of predicting FD length with a clinically sufficient accuracy in advance and could therefore be a helpful tool in intervention planning. Imaging data of high quality are mandatory, while processing and manipulation of the FD during the intervention may impact the accuracy.
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Affiliation(s)
- Robert Kellermann
- Department of Neuroradiology, Otto-von-Guericke University Magdeburg, Leipziger Straße 44, 39112, Magdeburg, Germany
| | - Steffen Serowy
- Department of Neuroradiology, Otto-von-Guericke University Magdeburg, Leipziger Straße 44, 39112, Magdeburg, Germany.
| | - Oliver Beuing
- Department of Neuroradiology, Otto-von-Guericke University Magdeburg, Leipziger Straße 44, 39112, Magdeburg, Germany
| | - Martin Skalej
- Department of Neuroradiology, Otto-von-Guericke University Magdeburg, Leipziger Straße 44, 39112, Magdeburg, Germany
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Djukic T, Saveljic I, Pelosi G, Parodi O, Filipovic N. Numerical simulation of stent deployment within patient-specific artery and its validation against clinical data. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2019; 175:121-127. [PMID: 31104701 DOI: 10.1016/j.cmpb.2019.04.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Revised: 04/02/2019] [Accepted: 04/07/2019] [Indexed: 05/05/2023]
Abstract
BACKGROUND AND OBJECTIVE One of the most widely adopted endovascular treatment procedures is the stent implantation. The effectiveness of the treatment depends on the appropriate stent expansion. However, it is difficult to accurately predict the outcome of such an endovascular intervention. Numerical simulations represent a useful tool to study the complex behavior of the stent during deployment. This study presents a numerical model capable of simulating this process. METHODS The numerical model consists of three parts: modeling of stent expansion, modeling the interaction of the stent with the arterial wall and the deformation of the arterial wall. The model is able to predict the shapes of both stent and arterial wall during the entire deployment process. Simulations are performed using patient-specific clinical data that ensures more realistic results. RESULTS The numerical simulations of stent deployment are performed using the extracted geometry of the coronary arteries of two patients. The obtained results are validated against clinical data from the follow up examination and both quantitative and qualitative analysis of the results is presented. The areas of several slices of the arterial wall are calculated for all the three states (before, after and follow up) and the standard error of the area when comparing simulation and follow up examination is 5.27% for patient #1 and 4.5% for patient #2. CONCLUSIONS The final goal of numerical simulations in stent deployment should be to provide a clinical tool that is capable of reliably predicting the treatment outcome. This study showed through the good agreement of results of the numerical simulations and clinical data that the presented numerical model represents a step towards this final goal. These simulations can also provide valuable information about distribution of forces and stress in the arterial wall that can improve pre-operative planning and treatment optimization.
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Affiliation(s)
- Tijana Djukic
- Bioengineering Research and Development Center, BioIRC, Prvoslava Stojanovica 6, 34000 Kragujevac, Serbia.
| | - Igor Saveljic
- Bioengineering Research and Development Center, BioIRC, Prvoslava Stojanovica 6, 34000 Kragujevac, Serbia; Faculty of Engineering, University of Kragujevac, Sestre Janjic 6, 34000 Kragujevac, Serbia.
| | - Gualtiero Pelosi
- Institute of Clinical Physiology, National Research Council, Via Giuseppe Moruzzi, 1, 56124 Pisa, Italy.
| | - Oberdan Parodi
- Institute of Clinical Physiology, National Research Council, Via Giuseppe Moruzzi, 1, 56124 Pisa, Italy.
| | - Nenad Filipovic
- Bioengineering Research and Development Center, BioIRC, Prvoslava Stojanovica 6, 34000 Kragujevac, Serbia; Faculty of Engineering, University of Kragujevac, Sestre Janjic 6, 34000 Kragujevac, Serbia
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Mut F, Chung BJ, Chudyk J, Lylyk P, Kadirvel R, Kallmes DF, Cebral JR. Image-based modeling of blood flow in cerebral aneurysms treated with intrasaccular flow diverting devices. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2019; 35:e3202. [PMID: 30891958 PMCID: PMC6687514 DOI: 10.1002/cnm.3202] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Revised: 01/18/2019] [Accepted: 03/17/2019] [Indexed: 05/20/2023]
Abstract
Modeling the flow dynamics in cerebral aneurysms after the implantation of intrasaccular devices is important for understanding the relationship between flow conditions created immediately posttreatment and the subsequent outcomes. This information, ideally available a priori based on computational modeling prior to implantation, is valuable to identify which aneurysms will occlude immediately and which aneurysms will likely remain patent and would benefit from a different procedure or device. In this report, a methodology for modeling the hemodynamics in intracranial aneurysms treated with intrasaccular flow diverting devices is described. This approach combines an image-guided, virtual device deployment within patient-specific vascular models with an immersed boundary method on adaptive unstructured grids. A partial mesh refinement strategy that reduces the number of mesh elements near the aneurysm dome where the flow conditions are largely stagnant was compared with the full refinement strategy that refines the mesh everywhere around the device wires. The results indicate that using the partial mesh refinement approach is adequate for analyzing the posttreatment hemodynamics, at a reduced computational cost. The results obtained on a series of four cerebral aneurysms treated with different intrasaccular devices were in good qualitative agreement with angiographic observations. Promising results were obtained relating posttreatment flow conditions and outcomes of treatments with intrasaccular devices, which need to be confirmed on larger series.
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Affiliation(s)
- Fernando Mut
- Bioengineering Department, Volgenau School of Engineering, George Mason University, Fairfax, Virginia, USA
| | - Bong Jae Chung
- Department of Mathematical Sciences, Montclair State University, Montclair, New Jersey, USA
| | - Jorge Chudyk
- Interventional Neuroradiology, Clinica ENERI, Buenos Aires, Argentina
| | - Pedro Lylyk
- Interventional Neuroradiology, Clinica ENERI, Buenos Aires, Argentina
| | | | - David F Kallmes
- Interventional Neuroradiology, Mayo Clinic, Rochester, Minnesota, USA
| | - Juan R Cebral
- Bioengineering Department, Volgenau School of Engineering, George Mason University, Fairfax, Virginia, USA
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Ospel JM, Gascou G, Costalat V, Piergallini L, Blackham KA, Zumofen DW. Comparison of Pipeline Embolization Device Sizing Based on Conventional 2D Measurements and Virtual Simulation Using the Sim&Size Software: An Agreement Study. AJNR Am J Neuroradiol 2019; 40:524-530. [PMID: 30733254 DOI: 10.3174/ajnr.a5973] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Accepted: 01/04/2019] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE The Sim&Size software simulates case-specific intraluminal Pipeline Embolization Device behavior, wall apposition, and device length in real-time on the basis of rotational angiography DICOM data. The purpose of this multicenter study was to evaluate whether preimplantation device simulation with the Sim&Size software results in selection of different device dimensions than manual sizing. MATERIALS AND METHODS In a multicenter cohort of 74 patients undergoing aneurysm treatment with the Pipeline Embolization Device, we compared apparent optimal device dimensions determined by neurointerventionalists with considerable Pipeline Embolization Device experience based on manual 2D measurements taken from rotational angiography with computed optimal dimensions determined by Sim&Size experts blinded to the neurointerventionalists' decision. Agreement between manually determined and computed optimal dimensions was evaluated with the Cohen κ. The significance of the difference was analyzed with the Wilcoxon signed rank test. RESULTS The agreement index between manual selection and computed optimal dimensions was low (κ for diameter = 0.219; κ for length = 0.149, P < .01). Computed optimal device lengths were significantly shorter (median, 14 versus 16 mm, T = 402, r = -0.28, P < .01). No significant difference was observed for device diameters. CONCLUSIONS Low agreement between manually determined and computed optimal device dimensions is not proof, per se, that virtual simulation performs better than manual selection. Nevertheless, it ultimately reflects the potential for optimization of the device-sizing process, and use of the Sim&Size software reduces, in particular, device length. Nevertheless, further evaluation is required to clarify the impact of device-dimension modifications on outcome.
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Affiliation(s)
- J M Ospel
- From the Diagnostic and Interventional Neuroradiology Section (J.M.O., K.A.B., D.W.Z.), Department of Radiology and Nuclear Medicine
| | - G Gascou
- Department of Neuroradiology (G.G., V.C., L.P.), Hôpital Gui de Chauliac, Centre Hospitalier Universitaire de Montpellier, University of Montpellier, Montpellier, France
| | - V Costalat
- Department of Neuroradiology (G.G., V.C., L.P.), Hôpital Gui de Chauliac, Centre Hospitalier Universitaire de Montpellier, University of Montpellier, Montpellier, France
| | - L Piergallini
- Department of Neuroradiology (G.G., V.C., L.P.), Hôpital Gui de Chauliac, Centre Hospitalier Universitaire de Montpellier, University of Montpellier, Montpellier, France.,Postgraduation School of Radiodiagnostics (L.P.), Università degli Studi di Milano, Milan, Italy
| | - K A Blackham
- From the Diagnostic and Interventional Neuroradiology Section (J.M.O., K.A.B., D.W.Z.), Department of Radiology and Nuclear Medicine
| | - D W Zumofen
- From the Diagnostic and Interventional Neuroradiology Section (J.M.O., K.A.B., D.W.Z.), Department of Radiology and Nuclear Medicine.,Department of Neurosurgery (D.W.Z.), University Hospital Basel, University of Basel, Basel, Switzerland
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39
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Dazeo N, Dottori J, Boroni G, Larrabide I. A comparative study of porous medium CFD models for flow diverter stents: Advantages and shortcomings. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2018; 34:e3145. [PMID: 30152120 DOI: 10.1002/cnm.3145] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Revised: 08/13/2018] [Accepted: 08/14/2018] [Indexed: 06/08/2023]
Abstract
In computational fluid dynamics, there is a high interest in modeling flow diverter stents as porous media due to its reduced computational loads. One of the main difficulties of such models is proper parameter setup. Most authors assume flow diverter's wire screen as an isotropic and homogeneous medium, while others proposes anisotropic configurations, yet very little is discussed about the effect of these assumptions on model's accuracy. In this paper, we compare the effect of different models on hemodynamics in relation to their parameters. The fidelity and efficiency of the different models to capture wire screen effect on fluid flow are quantitatively analyzed and compared.
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Affiliation(s)
- Nicolás Dazeo
- Pladema - CONICET, Universidad Nacional del Centro de la Provincia de Buenos Aires, Buenos Aires, Argentina
| | - Javier Dottori
- Pladema - CONICET, Universidad Nacional del Centro de la Provincia de Buenos Aires, Buenos Aires, Argentina
| | - Gustavo Boroni
- Pladema - CONICET, Universidad Nacional del Centro de la Provincia de Buenos Aires, Buenos Aires, Argentina
| | - Ignacio Larrabide
- Pladema - CONICET, Universidad Nacional del Centro de la Provincia de Buenos Aires, Buenos Aires, Argentina
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40
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Uchiyama Y, Takao H, Suzuki T, Fujimura S, Tanaka K, Otani K, Hayakawa M, Ishibashi T, Fukudome K, Mamori H, Yamamoto M, Murayama Y. Hemodynamic Change In A Cerebral Aneurysm Treated By Double Stenting Technique. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2018; 2018:1343-1346. [PMID: 30440640 DOI: 10.1109/embc.2018.8512461] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Rupture of cerebral aneurysms often causes subarachnoid hemorrhage which is a life-threatening condition with high mortality rates. Larger aneurysms are believed to be more likely to rupture and should therefore be treated. Recently, flow diverters (FDs) are widely used to treat large or wide neck aneurysms. However, it can be difficult to treat them by deployment of a single FD because of its insufficient flow disturbance. To overcome this problem, double stenting technique is sometimes applied with the aim to improve the effect of blood velocity reduction. In this study, we used computational fluid dynamics (CFD) to investigate the hemodynamic changes in an aneurysm when deploying virtual FDs. The results showed that the characteristics of the blood flow field inside the aneurysm did not changed much after the deployment of a single FD but underwent a large change after the deployment of two FDs. Furthermore, the velocity reduction in the aneurysm sac at a plane away from the parent artery increased from 25.9% to 92.8% when two FDs were deployed instead of one compared to no stenting. Double stenting was effective to decrease blood velocity in large or wide neck aneurysms.
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41
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Chen D, Wei J, Deng Y, Xu H, Li Z, Meng H, Han X, Wang Y, Wan J, Yan T, Xiong J, Tang X. Virtual stenting with simplex mesh and mechanical contact analysis for real-time planning of thoracic endovascular aortic repair. Theranostics 2018; 8:5758-5771. [PMID: 30555579 PMCID: PMC6276306 DOI: 10.7150/thno.28944] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Accepted: 10/06/2018] [Indexed: 11/29/2022] Open
Abstract
In aortic endovascular repair, the prediction of stented vessel remodeling informs treatment plans and risk evaluation; however, there are no highly accurate and efficient methods to quantitatively simulate stented vessels. This study developed a fast virtual stenting algorithm to simulate stent-induced aortic remodeling to assist in real-time thoracic endovascular aortic repair planning. Methods: The virtual stenting algorithm was established based on simplex deformable mesh and mechanical contact analysis. The key parameters of the mechanical contact analysis were derived from mechanical tests on aortic tissue (n=40) and commonly used stent-grafts (n=6). Genetic algorithm was applied to select weighting parameters. Testing and validation of the algorithm were performed using pre- and post-treatment computed tomography angiography datasets of type-B aortic dissection cases (n=66). Results: The algorithm was efficient in simulating stent-induced aortic deformation (mean computing time on a single processor: 13.78±2.80s) and accurate at the morphological (curvature difference: 1.57±0.57%; cross-sectional area difference: 4.11±0.85%) and hemodynamic (similarity of wall shear stress-derived parameters: 90.16-90.94%) levels. Stent-induced wall deformation was higher (p<0.05) in distal stent-induced new entry cases than in successfully treated cases, and this deformation did not differ significantly among the different stent groups. Additionally, the high stent-induced wall deformation regions and the new-entry sites overlapped, indicating the usefulness of wall deformation to evaluate the risks of device-induced complications. Conclusion: The novel algorithm provided fast real-time and accurate predictions of stent-graft deployment with luminal deformation tracking, thereby potentially informing individualized stenting planning and improving endovascular aortic repair outcomes. Large, multicenter studies are warranted to extend the algorithm validation and determine stress-induced wall deformation cutoff values for the risk stratification of particular complications.
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42
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Narata AP, Blasco J, Roman LS, Macho JM, Fernandez H, Moyano RK, Winzenrieth R, Larrabide I. Early Results in Flow Diverter Sizing by Computational Simulation: Quantification of Size Change and Simulation Error Assessment. Oper Neurosurg (Hagerstown) 2018; 15:557-566. [PMID: 29351652 DOI: 10.1093/ons/opx288] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Accepted: 12/20/2017] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Sizing of flow diverters (FDs) stent in the treatment of intracranial aneurysms is a challenging task due to the change of stent length after implantation. OBJECTIVE To quantify the size change and assess the error in length prediction in 82 simulated FD deployments. METHODS Eighty-two consecutive patients treated with FDs were retrospectively analyzed. Implanted FD length was measured from angiographic images and compared to the nominal sizes of the implanted device. Length change was obtained by subtracting the nominal length from the real length and dividing by the nominal length. Implanted devices were simulated on 3-dimensional models of each patient. Simulation error was obtained by subtracting real length from simulated length and dividing by the real length of the FD. Subanalysis was done using ANOVA. Statistical significance was set to P < .05, and bootstrap resampling was used. RESULTS When assessing the length change of the FD after implantation, changes of 30% in average and up to 80% with reference to the nominal length of the device were observed. The simulation results showed a lower error of 3.52% in average with a maximum of 30%. Paired t-test showed nonsignificant differences between measured and real length (P = .07, with the mean of differences at 0.45 mm, 95% confidence interval [-0.950 0.038]). CONCLUSION Nominal length is not an accurate sizing metric when choosing the size of an FD irrespective of the brand and manufacturer. Good estimation of the final length of the stent after deployment as expressed by an error of 3.5% in average.
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Affiliation(s)
- Ana Paula Narata
- CHRU Hospitaux de Tours, UMR "Imagerie et Cervau," Inserm U930, Université Francois-Rabelais, Tours, France
| | - Jordi Blasco
- Hospital Clinic Provincial de Barcelona, Barcelona, Spain
| | - Luis San Roman
- Hospital Clinic Provincial de Barcelona, Barcelona, Spain
| | | | | | | | | | - Ignacio Larrabide
- Galgo Medical SL, Barcelona, Spain.,Pladema, CONICET, UNICEN, Tandil, Argentina
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43
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Li J, Zhang Z, Wang S, Shang Z, Zhang G. A Specimen Extraction Instrument Based on Braided Fiber Tube for Natural Orifice Translumenal Endoscopic Surgery. J Med Device 2018. [DOI: 10.1115/1.4040638] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Natural orifice translumenal endoscopic surgery (NOTES) has offered significant advantages of less pain, reduced recovery time, and minimized scar after operation, demonstrating a promising development prospect. However, the large-size specimen extraction remains challenging for NOTES, due to the narrow space of the human natural orifices. To address such difficulties, a specimen extraction method that utilizes the braided fiber tube (BFT) structure with excellent retractility to accommodate and bind the bulky specimen has been proposed. Based on the theory of helical spring, the geometric model and the mechanical model of the BFT are established, and experiments have been performed to verify the accuracy of the derived mechanical model. In addition, a tensile test of using the BFT to extract large specimens via a small channel is carried out, which verifies the stable extraction performance of the proposed design. The BFT will not be damaged when extracting the specimen with a diameter less than 1.75 times of the channel diameter. A NOTES-specific specimen extraction instrument is designed according to the characteristics of NOTES, and it has three degrees-of-freedom and is able to actively capture different specimen by using a suction cup. Finally, specimen extraction experiments on NOTES multitasking platform phantom have been conducted using the prototyped instrument to validate its feasibility and effectiveness.
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Affiliation(s)
- Jinhua Li
- Key Laboratory for Mechanism Theory and Equipment Design of Ministry of Education, Tianjin University, Tianjin 300072, China e-mail:
| | - Zemin Zhang
- Key Laboratory for Mechanism Theory and Equipment Design of Ministry of Education, Tianjin University, Tianjin 300072, China e-mail:
| | - Shuxin Wang
- Key Laboratory for Mechanism Theory and Equipment Design of Ministry of Education, Tianjin University, Tianjin 300072, China e-mail:
| | - Zufeng Shang
- Key Laboratory for Mechanism Theory and Equipment Design of Ministry of Education, Tianjin University, Tianjin 300072, China e-mail:
| | - Guokai Zhang
- Key Laboratory for Mechanism Theory and Equipment Design of Ministry of Education, Tianjin University, Tianjin 300072, China e-mail:
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44
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Leng X, Wang Y, Xu J, Jiang Y, Zhang X, Xiang J. Numerical simulation of patient-specific endovascular stenting and coiling for intracranial aneurysm surgical planning. J Transl Med 2018; 16:208. [PMID: 30031395 PMCID: PMC6054731 DOI: 10.1186/s12967-018-1573-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Accepted: 07/07/2018] [Indexed: 11/17/2022] Open
Abstract
Background In this study, we develop reliable and practical virtual coiling and stenting methods for intracranial aneurysm surgical planning. Since the purpose of deploying coils and stents is to provide device geometries for subsequent accurate post-treatment computational fluid dynamics analysis, we do not need to accurately capture all the details such as the stress and force distribution for the devices and vessel walls. Our philosophy for developing these methods is to balance accuracy and practicality. Methods We consider the mechanical properties of the devices and recapitulate the clinical practice using a finite element method (FEM) approach. At the same time, we apply some simplifications for FEM modeling to make our methods efficient. For the virtual coiling, the coils are modeled as 3D Euler–Bernoulli beam elements, which is computationally efficient and provides good geometry representation. During the stent deployment process, the stent–catheter system is transformed according to the centerline of the parent vessel since the final configuration of the stent is not dependent of the deployment history. The aneurysm and vessel walls are assumed to be rigid and are fully constrained during the simulation. All stent–catheter system and coil–catheter system are prepared and packaged as a library which contains all types of stents, coils and catheters, which improves the efficiency of surgical planning process. Results The stent was delivered to the suitable position during the clinical treatment, achieving good expansion and apposition of the stent to the arterial wall. The coil was deployed into the aneurysm sac and deformed to different shapes because of the stored strain energy during coil package process and the direction of the microcatheter. Conclusions The method which we develop here could become surgical planning for intracranial aneurysm treatment in the clinical workflow.
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Affiliation(s)
- Xiaochang Leng
- ArteryFlow Technology Co., Ltd, 459 Qianmo Road, Suite C1-501, Binjiang District, Hangzhou, 310000, Zhejiang Province, China
| | - Yang Wang
- Department of Neurosurgery, The First Affiliated Hospital of Nanchang University, Nanchang University, Nanchang, China
| | - Jing Xu
- Department of Neurosurgery, The Second Affiliated Hospital of Zhejiang University, Zhejiang University, Hangzhou, China
| | - Yeqing Jiang
- Department of Radiology, Huashan Hospital Affiliated to Fudan University, No. 12 Wulumuqi Zhong Road, Shanghai, 200040, China
| | - Xiaolong Zhang
- Department of Radiology, Huashan Hospital Affiliated to Fudan University, No. 12 Wulumuqi Zhong Road, Shanghai, 200040, China.
| | - Jianping Xiang
- ArteryFlow Technology Co., Ltd, 459 Qianmo Road, Suite C1-501, Binjiang District, Hangzhou, 310000, Zhejiang Province, China.
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45
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Dreher ML, Nagaraja S, Bergstrom J, Hayman D. Development of a Flow Evolution Network Model for the Stress-Strain Behavior of Poly(L-lactide). J Biomech Eng 2018; 139:2633402. [PMID: 28617909 DOI: 10.1115/1.4037071] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Indexed: 11/08/2022]
Abstract
Computational modeling is critical to medical device development and has grown in its utility for predicting device performance. Additionally, there is an increasing trend to use absorbable polymers for the manufacturing of medical devices. However, computational modeling of absorbable devices is hampered by a lack of appropriate constitutive models that capture their viscoelasticity and postyield behavior. The objective of this study was to develop a constitutive model that incorporated viscoplasticity for a common medical absorbable polymer. Microtensile bars of poly(L-lactide) (PLLA) were studied experimentally to evaluate their monotonic, cyclic, unloading, and relaxation behavior as well as rate dependencies under physiological conditions. The data were then fit to a viscoplastic flow evolution network (FEN) constitutive model. PLLA exhibited rate-dependent stress-strain behavior with significant postyield softening and stress relaxation. The FEN model was able to capture these relevant mechanical behaviors well with high accuracy. In addition, the suitability of the FEN model for predicting the stress-strain behavior of PLLA medical devices was investigated using finite element (FE) simulations of nonstandard geometries. The nonstandard geometries chosen were representative of generic PLLA cardiovascular stent subunits. These finite element simulations demonstrated that modeling PLLA using the FEN constitutive relationship accurately reproduced the specimen's force-displacement curve, and therefore, is a suitable relationship to use when simulating stress distribution in PLLA medical devices. This study demonstrates the utility of an advanced constitutive model that incorporates viscoplasticity for simulating PLLA mechanical behavior.
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Affiliation(s)
- Maureen L Dreher
- Division of Applied Mechanics, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, U.S. Food and Drug Administration, 10903 New Hampshire Avenue, Silver Spring, MD 20993 e-mail:
| | - Srinidhi Nagaraja
- Division of Applied Mechanics, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, U.S. Food and Drug Administration, 10903 New Hampshire Avenue, Silver Spring, MD 20993 e-mail:
| | - Jorgen Bergstrom
- Veryst Engineering, 47A Kearney Road, Needham Heights, MA 02494 e-mail:
| | - Danika Hayman
- Veryst Engineering, 47A Kearney Road, Needham Heights, MA 02494 e-mail:
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46
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Fu W, Xia Q, Yan R, Qiao A. Numerical investigations of the mechanical properties of braided vascular stents. Biomed Mater Eng 2017; 29:81-94. [DOI: 10.3233/bme-171714] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- Wenyu Fu
- College of Mechanical and Electrical Engineering, Beijing Union University, Beijing 100020, China
- College of Architecture and Civil Engineering, Beijing University of Technology, Beijing 100124, China
| | - Qixiao Xia
- College of Mechanical and Electrical Engineering, Beijing Union University, Beijing 100020, China
| | - Ruobing Yan
- Department of Civil Engineering, University of Ottawa, Ottawa, K1N 6N5, Canada
| | - Aike Qiao
- College of Life Science and Bioengineering, Beijing University of Technology, Beijing 100124, China. E-mail:
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47
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Interaction between Flow Diverter and Parent Artery of Intracranial Aneurysm: A Computational Study. Appl Bionics Biomech 2017; 2017:3751202. [PMID: 29209136 PMCID: PMC5676342 DOI: 10.1155/2017/3751202] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Revised: 09/16/2017] [Accepted: 09/26/2017] [Indexed: 11/18/2022] Open
Abstract
To evaluate the influence of deployment strategy on the mechanical interaction between braided stent and parent artery of intracranial aneurysm (the elasticity of the arterial wall is considered), finite-element analyses are carried out by referring to computational models of flow-diverter device and arterial wall. Two implantation strategies are used to virtually implant the braided stent into the ideal intracranial aneurysm model. One is the noncompacted implantation method, and the other is the implantation method of using push-pull technique. During the process of the implantation, the changes of the arterial shape around the aneurysm and the changes of the wall pressure at the contact area between the braided stent and the inner wall of the artery are analyzed. The results indicate that the average contact pressure in the area of low porosity is 57 mmHg using the push-pull technique, and the average contact pressure of the parent artery is 10.45 mmHg using the non-push-pull technique. The diameter of the parent artery at the aneurismal orifice increased about 0.2 mm when using the push-pull technique, so the elasticity of the vessel should be considered in the mechanical analysis of interaction between stent and vessel.
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48
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Suzuki T, Takao H, Fujimura S, Dahmani C, Ishibashi T, Mamori H, Fukushima N, Murayama Y, Yamamoto M. Relationships between geometrical parameters and mechanical properties for a helical braided flow diverter stent. Technol Health Care 2017; 25:611-623. [DOI: 10.3233/thc-160535] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- Takashi Suzuki
- Graduate School of Mechanical Engineering, Tokyo University of Science, Tokyo 125-8585, Japan
| | - Hiroyuki Takao
- Graduate School of Mechanical Engineering, Tokyo University of Science, Tokyo 125-8585, Japan
- Division of Endovascular Neurosurgery, Department of Neurosurgery, The Jikei University School of Medicine, Tokyo 105-8461, Japan
- Department of Innovation for Medical Information Technology, The Jikei University School of Medicine, Tokyo 105-8461, Japan
| | - Soichiro Fujimura
- Graduate School of Mechanical Engineering, Tokyo University of Science, Tokyo 125-8585, Japan
| | - Chihebeddine Dahmani
- Division of Endovascular Neurosurgery, Department of Neurosurgery, The Jikei University School of Medicine, Tokyo 105-8461, Japan
| | - Toshihiro Ishibashi
- Division of Endovascular Neurosurgery, Department of Neurosurgery, The Jikei University School of Medicine, Tokyo 105-8461, Japan
| | - Hiroya Mamori
- Department of Mechanical Engineering, Tokyo University of Science, Tokyo 125-8585, Japan
| | - Naoya Fukushima
- Department of Mechanical Engineering, Tokyo University of Science, Tokyo 125-8585, Japan
| | - Yuichi Murayama
- Division of Endovascular Neurosurgery, Department of Neurosurgery, The Jikei University School of Medicine, Tokyo 105-8461, Japan
| | - Makoto Yamamoto
- Department of Mechanical Engineering, Tokyo University of Science, Tokyo 125-8585, Japan
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49
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FU WENYU, CHENG GUANG, YAN RUOBING, QIAO AIKE. NUMERICAL INVESTIGATIONS OF THE FLEXIBILITY OF INTRAVASCULAR BRAIDED STENT. J MECH MED BIOL 2017. [DOI: 10.1142/s0219519417500750] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Braided stents are commonly used to treat cerebral aneurysm, but there is little information about the bending characteristic of braided stent used for cerebral aneurysm. This paper investigates how geometrical parameters of braided stent influence its flexibility. Eight groups of braided stent models with different geometries (i.e., nominal diameter, length, braiding angle, number of wires, diameter of wire, frictional coefficient among wires and porosity) were constructed. Parametric analyses of these models were carried out by using Abaqus/Explicit. When the nominal diameter varied from 2[Formula: see text]mm to 5.5[Formula: see text]mm, the forces required for flexural deformation decrease from [Formula: see text][Formula: see text]N to [Formula: see text][Formula: see text]N; when the axial length varied from 10[Formula: see text]mm to 40[Formula: see text]mm, the forces required for flexural deformation decrease from [Formula: see text][Formula: see text]N to [Formula: see text][Formula: see text]N; when the braiding angle increases from 30[Formula: see text] to 75[Formula: see text] (the number of wires is 48 and the diameter of the wire is 0.026[Formula: see text]mm), the forces required for bending deformation decrease from [Formula: see text][Formula: see text]N to [Formula: see text][Formula: see text]N; when the diameter of wires increases from 0.026[Formula: see text]mm to 0.052[Formula: see text]mm (the number of wires is 24 and the braiding angle is 60[Formula: see text]), the forces required for flexural deformation increase from [Formula: see text][Formula: see text]N to [Formula: see text][Formula: see text]N; and when the number of wires increases from 14 to 48 (the braiding angle is 75[Formula: see text] and the diameter of the wire is 0.026[Formula: see text]mm), the forces required for flexural deformation increase from [Formula: see text][Formula: see text]N to [Formula: see text][Formula: see text]N. From the data above it can be seen that the diameter of wires, the number of wires and braiding angle have a larger impact on bending characteristics of braided stent; and the axial length and nominal diameter have a smaller impact on bending characteristics of braided stent. Results of the present study may provide theoretical guidance for the design of self-expanding braided stent and its clinical practice.
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Affiliation(s)
- WENYU FU
- College of Mechanical and Electrical Engineering, Beijing Union University, Beijing 100020, P. R. China
- Beijing Engineering Research Center of Smart Mechanical, Innovation Design Service, Beijing 100020, P. R. China
| | - GUANG CHENG
- College of Mechanical and Electrical Engineering, Beijing Union University, Beijing 100020, P. R. China
- Beijing Engineering Research Center of Smart Mechanical, Innovation Design Service, Beijing 100020, P. R. China
| | - RUOBING YAN
- Department of Civil Engineering, University of Ottawa, Ottawa, ON, Canada K1N 6N5, Canada
| | - AIKE QIAO
- College of Life Science and Bioengineering, Beijing University of Technology, Beijing 100124, P. R. China
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50
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Zhang M, Li Y, Zhao X, Verrelli DI, Chong W, Ohta M, Qian Y. Haemodynamic effects of stent diameter and compaction ratio on flow-diversion treatment of intracranial aneurysms: A numerical study of a successful and an unsuccessful case. J Biomech 2017; 58:179-186. [PMID: 28576622 DOI: 10.1016/j.jbiomech.2017.05.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2017] [Revised: 04/02/2017] [Accepted: 05/05/2017] [Indexed: 10/19/2022]
Abstract
BACKGROUND Compacting a flow-diverting (FD) stent is an emerging technique to create a denser configuration of wires across the aneurysm ostium. However, quantitative analyses of post-stenting haemodynamics affected by the compaction level of different stent sizes remain inconclusive. OBJECTIVE To compare the aneurysmal haemodynamic alterations after virtual FD treatments with different device diameters at different compaction ratios. METHODS We virtually implanted three sizes of FD stent, with each size deployed at four compaction ratios, into two patient aneurysms previously treated with the Silk+FD-one successful case and the other unsuccessful. Wire configurations of the FD in the 24 treatment scenarios were examined, and aneurysmal haemodynamic alterations were resolved by computational fluid dynamics (CFD) simulations. We investigated the aneurysmal flow patterns, aneurysmal average velocity (AAV), mass flowrate (MF), and energy loss (EL) in each scenario. RESULTS Compactions of the stent in the successful case resulted in a greater metal coverage rate than that achieved in the unsuccessful one. A 25% increment in compaction ratio further decreased the AAV (12%), MF (11%), and EL (9%) in both cases (average values). The averaged maximum differences attributable to device size were 10% (AAV), 8% (MF), and 9% (EL). CONCLUSIONS Both stent size and compaction level could markedly affect the FD treatment outcomes. It is therefore important to individualise the treatment plan by selecting the optimal stent size and deployment procedure. CFD simulation can be used to investigate the treatment outcomes, thereby assisting doctors in choosing a favourable treatment plan.
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Affiliation(s)
- Mingzi Zhang
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, New South Wales, Australia; Graduate School of Engineering, Tohoku University, Sendai, Miyagi, Japan
| | - Yujie Li
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, New South Wales, Australia; Graduate School of Engineering, Tohoku University, Sendai, Miyagi, Japan
| | - Xi Zhao
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, New South Wales, Australia
| | - David I Verrelli
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, New South Wales, Australia
| | - Winston Chong
- Neuroradiology Department, Monash Medical Centre, Melbourne, Victoria, Australia; Department of Surgery, School of Clinical Sciences, Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton, Victoria, Australia
| | - Makoto Ohta
- Institute of Fluid Science, Tohoku University, Sendai, Miyagi, Japan
| | - Yi Qian
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, New South Wales, Australia.
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