In-vivo Imaging of Femoral Artery Nitinol Stents for Deformation Analysis

Ganguly, Arundhuti; Simons, J. W.; Schneider, Alex; Keck, Benjamin; Bennett, Nathan R.; Herfkens, Robert J.; Coogan, Sheila M.; Fahrig, Rebecca

doi:10.1016/j.jvir.2010.10.019

Cited by 31 publications

(23 citation statements)

References 8 publications

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“…Several prior studies have used in vivo imaging [15 -17] to quantify limb flexion-induced deformations of the leg artery, but these measurements often relied on arterial side branches that tether the FPA to the surrounding tissues, thereby restricting deformations and resulting in significantly underestimated results [6,8]. Other studies have used stents [18][19][20][21] to assess deformations of the FPA, but because different stents affect baseline deformations differently [21 -23], these results may be applicable only to a particular device that was used to perform measurements. In addition, intricate stent patterns significantly complicate independent measurements of FPA deformation modes because many devices demonstrate coupled compression/bending/twisting/pinching behaviour [21,23].…”

Section: Introductionmentioning

confidence: 99%

Cross-sectional pinching in human femoropopliteal arteries due to limb flexion, and stent design optimization for maximum cross-sectional opening and minimum intramural stresses

Desyatova¹,

Poulson²,

MacTaggart³

et al. 2018

J. R. Soc. Interface.

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High failure rates of femoropopliteal artery (FPA) interventions are often attributed to severe mechanical deformations that occur with limb flexion. One of these deformations, cross-sectional pinching, has a direct effect on blood flow, but is poorly characterized. Intra-arterial markers were deployed into = 50 cadaveric FPAs (80 ± 12 years old, 14F/11M), and limbs were imaged in standing, walking, sitting and gardening postures. Image analysis was used to measure marker openings and calculate FPA pinching. Parametric finite element analysis on a stent section was used to determine the optimal combination of stent strut amplitude, thickness and the number of struts per section to maximize cross-sectional opening and minimize intramural mechanical stress and low wall shear stress. Pinching was higher distally and increased with increasing limb flexion. In the walking, sitting and gardening postures, it was 1.16-1.24, 1.17-1.26 and 1.19-1.35, respectively. Stent strut amplitude and thickness had strong effects on both intramural stresses and pinching. Stents with a strut amplitude of 3 mm, thickness of 175 µm and 20 struts per section produced pinching and intramural stresses typical for a non-stented FPA, while also minimizing low wall shear stress areas, and ensuring a stent lifespan of at least 10 cycles. These results can help guide the development of improved devices and materials to treat peripheral arterial disease.

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Section: Introductionmentioning

confidence: 99%

Cross-sectional pinching in human femoropopliteal arteries due to limb flexion, and stent design optimization for maximum cross-sectional opening and minimum intramural stresses

Desyatova¹,

Poulson²,

MacTaggart³

et al. 2018

J. R. Soc. Interface.

View full text Add to dashboard Cite

show abstract

“…46 Ganguly et al . 43 measured deformations of the stented FPA in patients using 3D CTA and obtained similar results. Finally, Ghriallais et al .…”

Section: Femoropopliteal Artery Obstructive Diseasementioning

confidence: 66%

Nitinol Stents in the Femoropopliteal Artery: A Mechanical Perspective on Material, Design, and Performance

et al. 2018

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Endovascular stenting has matured into a commonly used treatment for peripheral arterial disease (PAD) due to its minimally invasive nature and associated reductions in short-termmorbidity and mortality. The mechanical properties of the superelastic Nitinol alloy have played a major role in the explosion of peripheral artery stenting, with modern stents demonstrating reasonable resilience and durability. Yet in the superficial femoral and popliteal arteries, even the newest generation Nitinol stents continue to demonstrate clinical outcomes that leave significant room for improvement. Restenosis and progression of native arterial disease often lead to recurrence of symptoms and reinterventions that increase morbidity and health care expenditures. One of the main factors thought to be associated with stent failure in the femoropopliteal artery (FPA) is the unique and highly dynamic mechanical environment of the lower limb. Clinical and experimental data demonstrate that the FPA undergoes significant deformations with limb flexion. It is hypothesized that the inability of many existing stent designs to conform to these deformations likely plays a role in reconstruction failure, as repetitive movements of the leg and thigh combine with mechanical mismatch between the artery and the stent and result in mechanical damage to both the artery and the stent. In this review we will identify challenges and provide a mechanical perspective of FPA stenting, and then discuss current research directions with promise to provide a better understanding of Nitinol, specific features of stent design, and improved characterization of the biomechanical environment of the FPA to facilitate development of better stents for patients with PAD.

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“…In 2011, Ganguly et al [31] proposed a direct method to study femoral artery stent deformations in vivo. Using a C-arm computed tomography system, the authors acquired the data of 13 consenting volunteers with stents in femoral vessels, imaging in straight and bent positions to observe stent deformations.…”

Section: Discussionmentioning

confidence: 99%

Patient-specific finite element analysis of popliteal stenting

et al. 2016

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Nitinol self-expanding stents are used for the endovascular management of peripheral artery diseases of the popliteal artery, which is located behind the knee joint. Unfortunately, the complex kinematics of the artery during the leg flexion leads to severe loading conditions, favouring the mechanical failure of the stent, calling for a specific biomechanical analysis. For this reason, in the present study we reconstruct by medical image analysis the patient-specific popliteal kinematics during leg flexion, which is subsequently exploited to compute the mechanical response of a stent model, virtually implanted in the artery by structural finite element analysis (FEA). The medical image analysis indicates a non-uniform configuration change of the artery during the leg flexion, leading to an increase of the vessel curvature above the knee. The computed mechanical response of the stent reflects the non-uniform configuration change of the artery as after the flexion the average stress is higher in the part of the stent located above the knee. Although the proposed analysis is limited to a case-study, it shows the capability of patient-specific FEA simulations to compute the mechanical response of a stent model subjected to the complex and severe loading conditions of the popliteal artery during leg flexion

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In-vivo Imaging of Femoral Artery Nitinol Stents for Deformation Analysis

Abstract: The imaging and analysis approach developed based on calibrated in vitro measurements was extended to in-vivo data. Bending and tension forces were successfully evaluated in this pilot study.

Cited by 31 publications

References 8 publications

Cross-sectional pinching in human femoropopliteal arteries due to limb flexion, and stent design optimization for maximum cross-sectional opening and minimum intramural stresses

Cross-sectional pinching in human femoropopliteal arteries due to limb flexion, and stent design optimization for maximum cross-sectional opening and minimum intramural stresses

Nitinol Stents in the Femoropopliteal Artery: A Mechanical Perspective on Material, Design, and Performance

Patient-specific finite element analysis of popliteal stenting

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