Development of a Virtual Stent Deployment Application to Estimate Patient-Specific Braided Stent Sizes

The instant mechanical behaviors of stenotic coronary artery and deployed stents have significant impacts on percutaneous coronary intervention prognosis. However, they could not be obtained directly from the current examination techniques, which are commonly used in clinical practice. Thus, we intend to investigate the instantaneous mechanical behaviors of deployed stent and artery through virtually stenting technology based on a real clinical case in assessment of geometric and biomechanical characteristics. Method: Finite element analysis models, including rigid guide catheter, six-folded balloon with conical tip, crimped and bended stent, stenotic coronary artery with soft plaques, were simulated through virtual mechanical expansion and recoil procedure. The morphology changes of coronary lumen, strain and stress distribution of involved components at different stages and apposition of stent struts were analyzed. Results: Lumen in the stenotic region restored patency obviously at maximum expansion and had an elastic recoil about 13.5% later. The maximum principal stress distribution of artery walls and plaque was mainly concentrated in the stenotic segment with the peak value of 1.252[Formula: see text]MPa and 2.975[Formula: see text]MPa at max expansion, 0.713[Formula: see text]MPa and 1.25[Formula: see text]MPa after recoil, respectively. The higher von Mises stress and plastic equivalent strain of stent were present at the bended strut and inter-ring connectors with the peak value of 714.2[Formula: see text]MPa and 0.2385 at max expansion, 694[Formula: see text]MPa and 0.2276 after recoil. Slight malappositions were found in the proximal segment and struts distribution in the stenotic sites showed certain asymmetry. Conclusion: The instant mechanical behaviors of artery and stent could be evaluated through virtual stenting approach in assessment of geometric and biomechanical characteristics. This may contribute to choosing the best stenting schemes and predicting the clinical outcomes for a specific patient.

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3D Reconstruction of Coronary Artery Stents From Optical Coherence Tomography: Experimental Validation and Clinical Feasibility

10.21203/rs.3.rs-154558/v1 ◽

2021 ◽

Author(s):

Wei Wu ◽

Khan Behram A. ◽

Mohammadali Sharzehee ◽

Shijia Zhao ◽

Saurabhi Samant ◽

...

Keyword(s):

Coronary Artery ◽

3D Reconstruction ◽

Coronary Arteries ◽

Side Branch ◽

Patient Specific ◽

Micro Computed Tomography ◽

Stent Deployment ◽

Structural Morphology ◽

Stent Strut ◽

Coronary Artery Stents

Abstract The structural morphology of stents (e.g. expansion, lumen scaffolding, strut apposition, tissue protrusion, side branch jailing, strut fracture), and the local hemodynamic environment after stent deployment in coronary arteries are key determinants of procedural success and subsequent clinical outcomes. High-resolution intracoronary imaging has the potential to enable the geometrically correct 3D reconstruction of coronary stents. The aim of this work was to present a novel algorithm for 3D stent reconstruction of coronary artery stents by OCT and angiography, and test experimentally its accuracy, reproducibility, clinical feasibility and ability to perform CFD studies. Our method has the following steps: 3D lumen reconstruction by OCT and angiography, stent strut segmentation on OCT images, packaging, rotation and straightening of the segmented struts, and planar unrolling of the segmented struts, planar stent wireframe reconstruction, rolling back of the planar stent wireframe to the 3D reconstructed lumen, and stent volume reconstruction. We tested the accuracy and reproducibility of our method in stented patient-specific silicone models using micro computed tomography and stereoscopy as reference. The clinical feasibility and CFD studies were performed in clinically stented coronary bifurcations. Our experimental and clinical studies showed that our proposed algorithm can reproduce the complex stent configuration in space with high precision and reproducibility. Furthermore, our studies showed that the algorithm is feasible in clinical cases with stents deployed in diseased, bifurcated coronary arteries, enabling CFD studies to assess the hemodynamic environment. Notably, the high accuracy of our algorithm was consistent across different stent designs and diameters. Our method coupled with patient-specific CFD studies can facilitate stenting optimization, training in stenting techniques, and stent research and development.

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Leo Stent for Endovascular Treatment of Broad-Necked and Fusiform Intracranial Aneurysms

Interventional Neuroradiology ◽

10.1177/159101990701300305 ◽

2007 ◽

Vol 13 (3) ◽

pp. 255-269 ◽

Cited By ~ 23

Author(s):

R. Juszkat ◽

S. Nowak ◽

S. Smóal ◽

W. Kociemba ◽

T. Blok ◽

...

Keyword(s):

Endovascular Treatment ◽

Coil Embolization ◽

Intracranial Aneurysms ◽

Internal Carotid ◽

Aneurysm Rupture ◽

Parent Vessel ◽

Stent Deployment ◽

Acute Setting ◽

Aneurysm Occlusion ◽

Braided Stent

The advent of intracranial stents has widened the indications for endovascular treatment of broad-necked and fusiform aneurysms. Leo stent is a self-expandable, nitinol, braided stent dedicated to intracranial vessels. The aim of this study is to present our experience in endovascular treatment of broad-necked and fusiform intracranial aneurysms using self-expanding, nitinol Leo stents. Between February 2004 and November 2006, 25 broad-necked and three fusiform aneurysms in 28 patients were treated using Leo stents in our centre. There were 18 patients who experienced acute subarachnoid haemorrhage due to aneurysm rupture, two patients who experienced SAH at least 12 months ago and in eight patients aneurysms were found incidentally. Aneurysms were located as follows: internal carotid artery, basilar artery, basilar tip, posterior inferior cerebral artery, M1/M2 segment, A2 segment and vertebral artery. There were no difficulties with stent deployment and delivery. All patients after acute SAH (n=18) underwent stent implantation and coil embolization in one procedure. The remaining patients underwent coil embolization in a staged procedure. Immediate aneurysm occlusion of more than 95% was achieved in all patients who underwent stent placement and coil embolization in one procedure. There were three thromboembolic complications encountered in patients in an acute setting of SAH, preloaded only on acetylsalicylic acid. Use of abciximab led to patency within the stent and parent vessel. However, one of these patients presented rebleeding from the aneurysm during administration of abciximab and died. Application of Leo stents in cases of broad-necked and fusiform intracranial aneurysms is safe and effective with a low complication rate.

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Mechanical Behaviors of the Stent Deployment Inside A Patient-Specific Stenotic Coronary Artery

Proceedings of the 2019 9th International Conference on Biomedical Engineering and Technology - ICBET' 19 ◽

10.1145/3326172.3326188 ◽

2019 ◽

Author(s):

Liu Yuqian ◽

Pan Lianqiang ◽

Wu Heng ◽

Lin Changyan

Keyword(s):

Coronary Artery ◽

Patient Specific ◽

Mechanical Behaviors ◽

Stent Deployment

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Finite Element Modelling of Stent Deployment in a Patient-specific Coronary Artery

Procedia Structural Integrity ◽

10.1016/j.prostr.2019.07.006 ◽

2019 ◽

Vol 15 ◽

pp. 28-32

Author(s):

Ran He ◽

Liguo Zhao ◽

Vadim V. Silberschmidt ◽

Yang Liu ◽

Felix Vogt

Keyword(s):

Finite Element ◽

Coronary Artery ◽

Finite Element Modelling ◽

Patient Specific ◽

Stent Deployment ◽

Element Modelling

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Computational modeling of braided-stent deployment for interpreting the mechanism of stent flattening

International Journal for Numerical Methods in Biomedical Engineering ◽

10.1002/cnm.3335 ◽

2020 ◽

Author(s):

Shunya Shiozaki ◽

Tomohiro Otani ◽

Soichiro Fujimura ◽

Hiroyuki Takao ◽

Shigeo Wada

Keyword(s):

Computational Modeling ◽

Stent Deployment ◽

Braided Stent

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Effects of Material on the Deployment of Coronary Stents

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.123-125.315 ◽

2010 ◽

Vol 123-125 ◽

pp. 315-318 ◽

Cited By ~ 2

Author(s):

Sriram Tammareddi ◽

Qing Li

Keyword(s):

Computational Approach ◽

Quantitative Comparison ◽

Coronary Stents ◽

Patient Specific ◽

Stent Deployment ◽

Explicit Finite Element ◽

The Past ◽

Stent Geometry ◽

Specific Assessment ◽

Biomechanical Responses

Coronary stents have been more and more widely used in clinic over the past decade. There have been a large number of stents made of different biocompatible materials available commercially in the market. It is however unclear which is more suitable to specific patients. This raises a major concern whether the choice of stents could be assessed before a delivery surgery. This paper aims to provide a computational approach for evaluating the effect of stent materials on biomechanical outcomes of the deployments of stents in different patient. It will review the typical biomaterials being used for coronary stents, seeking to qualitatively assess them for use as coronary stents. Non-linear explicit finite element (FE) procedure is carried out using the Palmaz-Schatz stent geometry to quantitatively predict the effect of mechanical properties of these biomaterials on stent and coronary artery behavior during stent deployment. A quantitative comparison is made for exploring the effect of different materials on the deployment of stents. The study is considered significant in understanding the role how stent materials affect biomechanical responses to the coronary stenting. It provides a new methodology to promote a patient-specific assessment before surgery.

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Three dimensional reconstruction of coronary artery stents from optical coherence tomography: experimental validation and clinical feasibility

Scientific Reports ◽

10.1038/s41598-021-91458-y ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Wei Wu ◽

Behram Khan ◽

Mohammadali Sharzehee ◽

Shijia Zhao ◽

Saurabhi Samant ◽

...

Keyword(s):

Optical Coherence Tomography ◽

Coronary Artery ◽

Three Dimensional ◽

Coronary Stents ◽

Patient Specific ◽

Optical Coherence ◽

Micro Computed Tomography ◽

Stent Deployment ◽

Structural Morphology ◽

Coronary Artery Stents

AbstractThe structural morphology of coronary stents (e.g. stent expansion, lumen scaffolding, strut apposition, tissue protrusion, side branch jailing, strut fracture), and the local hemodynamic environment after stent deployment are key determinants of procedural success and subsequent clinical outcomes. High-resolution intracoronary imaging has the potential to enable the geometrically accurate three-dimensional (3D) reconstruction of coronary stents. The aim of this work was to present a novel algorithm for 3D stent reconstruction of coronary artery stents based on optical coherence tomography (OCT) and angiography, and test experimentally its accuracy, reproducibility, clinical feasibility, and ability to perform computational fluid dynamics (CFD) studies. Our method has the following steps: 3D lumen reconstruction based on OCT and angiography, stent strut segmentation in OCT images, packaging, rotation and straightening of the segmented struts, planar unrolling of the segmented struts, planar stent wireframe reconstruction, rolling back of the planar stent wireframe to the 3D reconstructed lumen, and final stent volume reconstruction. We tested the accuracy and reproducibility of our method in stented patient-specific silicone models using micro-computed tomography (μCT) and stereoscopy as references. The clinical feasibility and CFD studies were performed in clinically stented coronary bifurcations. The experimental and clinical studies showed that our algorithm (1) can reproduce the complex spatial stent configuration with high precision and reproducibility, (2) is feasible in 3D reconstructing stents deployed in bifurcations, and (3) enables CFD studies to assess the local hemodynamic environment within the stent. Notably, the high accuracy of our algorithm was consistent across different stent designs and diameters. Our method coupled with patient-specific CFD studies can lay the ground for optimization of stenting procedures, patient-specific computational stenting simulations, and research and development of new stent scaffolds and stenting techniques.

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Comparison of intra-aneurysmal flow modification using optical flow imaging to evaluate the performance of Evolve and Pipeline flow diverting stents

Journal of NeuroInterventional Surgery ◽

10.1136/neurintsurg-2019-015696 ◽

2020 ◽

Vol 12 (8) ◽

pp. 814-817 ◽

Cited By ~ 3

Author(s):

Nicole Mariantonia Cancelliere ◽

Patrick Nicholson ◽

Ivan Radovanovic ◽

Karla Mirella Mendes ◽

Emanuele Orru ◽

...

Keyword(s):

Optical Flow ◽

Stent Placement ◽

Flow Analysis ◽

Flow Diversion ◽

Patient Specific ◽

Stent Deployment ◽

Flow Modification ◽

Before And After ◽

Carotid Aneurysms

BackgroundFlow diverting stent (FDS) devices have revolutionized the treatment of large and complex brain aneurysms, but there is still room for improvement, particularly on the flow diversion properties and technical challenges associated with stent deployment. In this study we compared flow diversion properties between the new generation Surpass Evolve (Stryker) and the Pipeline Flex (Medtronic) devices by quantitatively evaluating intra-aneurysmal flow modification.MethodsAn in vitro experimental set-up was used, consisting of four patient-specific silicone models with internal carotid aneurysms and a circulating hemodynamic simulation system with pulsatile flow. The Evolve and Pipeline stents were deployed across the neck of each aneurysm model, in a randomized fashion, for a total of eight device deployments. A 60 frames/s digital subtraction angiography run was acquired before and after placement of each FDS. An optical flow-analysis method was used to measure intra-aneurysmal flow modification induced by the stent by calculating a mean aneurysm flow amplitude (MAFA) before and after stent placement and computing a ratio.ResultsAverage MAFA ratio values calculated from pre- and post-stent placement were significantly lower after deployment of the Evolve (n=4, mean=0.62±0.09) compared with the Pipeline device (n=4, mean=0.71±0.06) (p=0.03).ConclusionsOur in vitro results show that the Evolve stent had a superior flow diversion effect compared with the Pipeline stent, which—based on clinical evidence—suggest it may promote faster aneurysm occlusion rates in patients.

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