Failure properties of vena cava tissue due to deep penetration during filter insertion

Numer Methods Biomed Eng

2018

We present a computational framework that integrates experimental techniques and finite element modeling to calibrate material fracture parameters of the vena cava and the interaction properties between a retrievable filter (Günther Tulip) and the vena cava wall. The fitted parameters were then used to analyze the interaction of the inferior vena cava filter with the vena cava during the deployment process. An idealized cava finite element model was then developed including residual stresses and physiological pressure conditions. Filter deployment was simulated, and a comprehensive study of tissue-filter interaction was performed by cohesive surface modeling. Simulations predict that there are no fracture areas for either model, so we can conclude that there is no penetration of the anchor into the vena cava. This suggests there are other physiological situations, such as the Valsalva maneuver, which could produce this penetration observed on some patients.

normalΨ false(boldC, m_{0}, n_{0} false) = Ψ_{v o l} false(J false) + Ψ_{i s o} false(bold \overset{bold¯}{boldC}, m_{0} \otimes m_{0}, n_{0} \otimes n_{0} false),

where Ψ v o l ( J ) and

Ψ_{i s o} false(bold \overset{bold¯}{boldC}, m_{0} \otimes m_{0}, n_{0} \otimes n_{0} false)

describe the volumetric and the isochoric responses of the material, respectively.…”

Section: Mechanical Modeling Of Filter and Vena Cava Tissuementioning

confidence: 99%

χ^{2} = {normalΣ}_{i = 1}^{n} ([], {((), σ_{θ θ} - σ_{θ θ}^{\overset{Ψ}{true}})}_{i}^{2} + {((), σ_{z z} - σ_{z z}^{\overset{Ψ}{true}})}_{i}^{2}) .

…”

Section: Mechanical Modeling Of Filter and Vena Cava Tissuementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Calibration of interface properties and application to a finite element model for predicting vena cava filter–induced vein wall failure

Pérez-Andrés

Numer Methods Biomed Eng

2018

Failure damage mechanical properties of thoracic and abdominal porcine aorta layers and related constitutive modeling: phenomenological and microstructural approach

Martı́nez

Biomech Model Mechanobiol

2019

Despite increasing experimental and analytical efforts to investigate the irreversible effects of arterial tissue failure, the underlying mechanisms are still poorly understood. The goal of this study was characterize the failure properties of the intact wall and each separated layer (intima, media and adventitia) of the descending thoracic and infrarenal abdominal aorta and to test the hypothesis that the failure properties of layer-separated tissue depend on the location of the aorta. To test this hypothesis, we performed uniaxial tests to study the mechanical behavior of both intact and layer-separated porcine aortic tissue samples taken from descending thoracic and infrarenal abdominal aorta until complete failure. The fracture stress is higher in the infrarenal abdominal aorta than in the equivalent descending thoracic aorta. It was also found that the extrapolation of the elastic mechanical properties from the physiological to the supra-physiological regime for characterizing the mechanical response of the aorta would be inappropriate. Finally, we report values of constitutive parameters using phenomenological and microstructural damage models based on Continuum Damage Mechanics Theory. The phenomenological damage model gives an excellent fit to the experimental data compared to the microstructural damage model. Although the fitting

The Importance of Hemorheology and Patient Anatomy on the Hemodynamics in the Inferior Vena Cava

et al. 2016

Inferior vena cava (IVC) filters have been used for nearly half a century to prevent pulmonary embolism in at-risk patients. However, complications with IVC filters remain common. In this study, we investigate the importance of considering the hemorheological and morphological effects on IVC hemodynamics by simulating Newtonian and non-Newtonian blood flow in three IVC models with varying levels of geometric idealization. Partial occlusion by an IVC filter and a thrombus is also considered. More than 99% of the infrarenal IVC volume is found to contain flow in the nonlinear region of the shear rate-viscosity curve for blood (less than 100 s) in the unoccluded IVCs. Newtonian simulations performed using the asymptotic viscosity for blood over-predict the non-Newtonian Reynolds numbers by more than a factor of two and under-predict the mean wall shear stress (WSS) by 28-54%. Agreement with the non-Newtonian simulations is better using a characteristic viscosity, but local WSS errors are still large (up to 50%) in the partially occluded cases. Secondary flow patterns in the IVC also depend on the viscosity model and IVC morphological complexity. Non-Newtonian simulations required only a marginal increase in computational expense compared with the Newtonian simulations. We recommend that future studies of IVC hemodynamics consider the effects of hemorheology and IVC morphology when accurate predictions of WSS and secondary flow features are desired.