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Michael S Sacks - One of the best experts on this subject based on the ideXlab platform.

  • isogeometric finite element based simulation of the aortic heart Valve integration of neural network structural material model and structural tensor fiber architecture representations
    International Journal for Numerical Methods in Biomedical Engineering, 2021
    Co-Authors: Wenbo Zhang, Giovanni Rossini, David Kamensky, Tan Buithanh, Michael S Sacks
    Abstract:

    The functional complexity of native and replacement aortic heart Valves are well known, incorporating such physical phenomenons as time-varying non-linear anisotropic soft tissue mechanical behavior, geometric non-linearity, complex multi-surface time varying contact, and fluid-structure interactions to name a few. It is thus clear that computational simulations are critical in understanding AV function and for the rational basis for design of their replacements. However, such approaches continued to be limited by ad-hoc approaches for incorporating tissue fibrous structure, high-fidelity material models, and Valve geometry. To this end, we developed an integrated tri-Leaflet Valve pipeline built upon an isogeometric analysis (IGA) framework. A high-order structural tensor (HOST) based method was developed for efficient storage and mapping the two-dimensional fiber structural data onto the valvular 3D geometry. We then developed a neural network (NN) material model that learned the responses of a detailed mesostructural model for exogenously cross-linked planar soft tissues. The NN material model not only reproduced the full anisotropic mechanical responses but also demonstrated a considerable efficiency improvement, as it was trained over a range of realizable fibrous structures. Results of parametric simulations were then performed, as well as population based bicuspid aortic heart Valve fiber structure, that demonstrated the efficiency and robustness of the present approach. In summary, the present approach that integrates HOST and NN material model provides an efficient computational analysis framework with increased physical and functional realism for the simulation of native and replacement tri-Leaflet heart Valves. This article is protected by copyright. All rights reserved.

  • Isogeometric finite element‐based simulation of the aortic heart Valve: Integration of neural network structural material model and structural tensor fiber architecture representations
    International journal for numerical methods in biomedical engineering, 2021
    Co-Authors: Wenbo Zhang, Giovanni Rossini, David Kamensky, Tan Bui-thanh, Michael S Sacks
    Abstract:

    The functional complexity of native and replacement aortic heart Valves are well known, incorporating such physical phenomenons as time-varying non-linear anisotropic soft tissue mechanical behavior, geometric non-linearity, complex multi-surface time varying contact, and fluid-structure interactions to name a few. It is thus clear that computational simulations are critical in understanding AV function and for the rational basis for design of their replacements. However, such approaches continued to be limited by ad-hoc approaches for incorporating tissue fibrous structure, high-fidelity material models, and Valve geometry. To this end, we developed an integrated tri-Leaflet Valve pipeline built upon an isogeometric analysis (IGA) framework. A high-order structural tensor (HOST) based method was developed for efficient storage and mapping the two-dimensional fiber structural data onto the valvular 3D geometry. We then developed a neural network (NN) material model that learned the responses of a detailed mesostructural model for exogenously cross-linked planar soft tissues. The NN material model not only reproduced the full anisotropic mechanical responses but also demonstrated a considerable efficiency improvement, as it was trained over a range of realizable fibrous structures. Results of parametric simulations were then performed, as well as population based bicuspid aortic heart Valve fiber structure, that demonstrated the efficiency and robustness of the present approach. In summary, the present approach that integrates HOST and NN material model provides an efficient computational analysis framework with increased physical and functional realism for the simulation of native and replacement tri-Leaflet heart Valves. This article is protected by copyright. All rights reserved.

  • Effect of Geometry on the Leaflet Stresses in Simulated Models of Congenital Bicuspid Aortic Valves
    Cardiovascular Engineering and Technology, 2011
    Co-Authors: Paul N. Jermihov, Michael S Sacks, Lu Jia, Robert C. Gorman, Joseph H. Gorman, Krishnan B. Chandran
    Abstract:

    The aim of the study was to assess the effect of geometric variations on the stresses developed in the Leaflets of congenital bicuspid aortic Valves (CBAV). We developed a model for the human tri-Leaflet aortic Valve based on the geometry and dimensions published in the literature. We also developed simulated CBAV geometry based on the most common geometry present in patients with CBAV that is published in the literature. We employed a constitutive relationship for the Leaflet material from the previously published experimental data of fresh porcine aortic Valve Leaflet specimens for the analysis. We performed dynamic finite element (FE) structural analysis of the Valves in the aortic position in order to compute the strain and stress distribution on the Leaflets of the tri-Leaflet Valve and the CBAV models. Our results showed that large changes in the computed in-plane Leaflet strain and stress occurred with variations in the geometry of the simulated CBAV whereas changes due to alterations in material constants were correspondingly less. The Valve orifice area in the fully open position was significantly reduced in CBAV compared to that for the tri-Leaflet Valve. The changes in geometry of CBAV resulted in large changes in in-plane strain and stress and our results suggest that geometrical variations may be a potential risk factor inducing calcific aortic stenosis frequently present in patients with CBAV.

  • the role of organ level conditioning on the promotion of engineered heart Valve tissue development in vitro using mesenchymal stem cells
    Biomaterials, 2010
    Co-Authors: Sharan Ramaswamy, John E. Mayer, George C Engelmayr, Danielle Gottlieb, David E. Schmidt, Elena Aikawa, Virna L. Sales, Diana M Gaitanleon, Michael S Sacks
    Abstract:

    Abstract We have previously shown that combined flexure and flow (CFF) augment engineered heart Valve tissue formation using bone marrow-derived mesenchymal stem cells (MSC) seeded on polyglycolic acid (PGA)/poly-L-lactic acid (PLLA) blend nonwoven fibrous scaffolds (Engelmayr, et al., Biomaterials 2006; vol. 27 pp. 6083–95). In the present study, we sought to determine if these phenomena were reproducible at the organ level in a functional tri-Leaflet Valve. Tissue engineered Valve constructs (TEVC) were fabricated using PGA/PLLA nonwoven fibrous scaffolds then seeded with MSCs. Tissue formation rates using both standard and augmented (using basic fibroblast growth factor [bFGF] and ascorbic acid-2-phosphate [AA2P]) media to enhance the overall production of collagen were evaluated, along with their relation to the local fluid flow fields. The resulting TEVCs were statically cultured for 3 weeks, followed by a 3 week dynamic culture period using our organ level bioreactor (Hildebrand et al., ABME, Vol. 32, pp. 1039–49, 2004) under approximated pulmonary artery conditions. Results indicated that supplemented media accelerated collagen formation (∼185% increase in collagen mass/MSC compared to standard media), as well as increasing collagen mass production from 3.90 to 4.43 pg/cell/week from 3 to 6 weeks. Using augmented media, dynamic conditioning increased collagen mass production rate from 7.23 to 13.65 pg/cell/week (88.8%) during the dynamic culture period, along with greater preservation of net DNA. Moreover, when compared to our previous CFF study, organ level conditioning increased the collagen production rate from 4.76 to 6.42 pg/cell/week (35%). Newly conducted CFD studies of the CFF specimen flow patterns suggested that oscillatory surface shear stresses were surprisingly similar to a tri-Leaflet Valve. Overall, we found that the use of simulated pulmonary artery conditions resulted in substantially larger collagen mass production levels and rates found in our earlier CFF study. Moreover, given the fact that the scaffolds underwent modest strains (∼7% max) during either CFF or physiological conditioning, the oscillatory surface shear stresses estimated in both studies may play a substantial role in eliciting MSC collagen production in the highly dynamic engineered heart Valve fluid mechanical environment.

  • The role of organ level conditioning on the promotion of engineered heart Valve tissue development in-vitro using mesenchymal stem cells
    Biomaterials, 2009
    Co-Authors: Sharan Ramaswamy, John E. Mayer, George C Engelmayr, Danielle Gottlieb, David E. Schmidt, Elena Aikawa, Diana M. Gaitan-leon, Virna L. Sales, Michael S Sacks
    Abstract:

    We have previously shown that combined flexure and flow (CFF) augment engineered heart Valve tissue formation using bone marrow-derived mesenchymal stem cells (MSC) seeded on polyglycolic acid (PGA)/poly-L-lactic acid (PLLA) blend nonwoven fibrous scaffolds (Engelmayr, et al., Biomaterials 2006; vol. 27 pp. 6083-95). In the present study, we sought to determine if these phenomena were reproducible at the organ level in a functional tri-Leaflet Valve. Tissue engineered Valve constructs (TEVC) were fabricated using PGA/PLLA nonwoven fibrous scaffolds then seeded with MSCs. Tissue formation rates using both standard and augmented (using basic fibroblast growth factor [bFGF] and ascorbic acid-2-phosphate [AA2P]) media to enhance the overall production of collagen were evaluated, along with their relation to the local fluid flow fields. The resulting TEVCs were statically cultured for 3 weeks, followed by a 3 week dynamic culture period using our organ level bioreactor (Hildebrand et al., ABME, Vol. 32, pp. 1039-49, 2004) under approximated pulmonary artery conditions. Results indicated that supplemented media accelerated collagen formation (approximately 185% increase in collagen mass/MSC compared to standard media), as well as increasing collagen mass production from 3.90 to 4.43 pg/cell/week from 3 to 6 weeks. Using augmented media, dynamic conditioning increased collagen mass production rate from 7.23 to 13.65 pg/cell/week (88.8%) during the dynamic culture period, along with greater preservation of net DNA. Moreover, when compared to our previous CFF study, organ level conditioning increased the collagen production rate from 4.76 to 6.42 pg/cell/week (35%). Newly conducted CFD studies of the CFF specimen flow patterns suggested that oscillatory surface shear stresses were surprisingly similar to a tri-Leaflet Valve. Overall, we found that the use of simulated pulmonary artery conditions resulted in substantially larger collagen mass production levels and rates found in our earlier CFF study. Moreover, given the fact that the scaffolds underwent modest strains (approximately 7% max) during either CFF or physiological conditioning, the oscillatory surface shear stresses estimated in both studies may play a substantial role in eliciting MSC collagen production in the highly dynamic engineered heart Valve fluid mechanical environment.

Sharan Ramaswamy - One of the best experts on this subject based on the ideXlab platform.

  • the role of organ level conditioning on the promotion of engineered heart Valve tissue development in vitro using mesenchymal stem cells
    Biomaterials, 2010
    Co-Authors: Sharan Ramaswamy, John E. Mayer, George C Engelmayr, Danielle Gottlieb, David E. Schmidt, Elena Aikawa, Virna L. Sales, Diana M Gaitanleon, Michael S Sacks
    Abstract:

    Abstract We have previously shown that combined flexure and flow (CFF) augment engineered heart Valve tissue formation using bone marrow-derived mesenchymal stem cells (MSC) seeded on polyglycolic acid (PGA)/poly-L-lactic acid (PLLA) blend nonwoven fibrous scaffolds (Engelmayr, et al., Biomaterials 2006; vol. 27 pp. 6083–95). In the present study, we sought to determine if these phenomena were reproducible at the organ level in a functional tri-Leaflet Valve. Tissue engineered Valve constructs (TEVC) were fabricated using PGA/PLLA nonwoven fibrous scaffolds then seeded with MSCs. Tissue formation rates using both standard and augmented (using basic fibroblast growth factor [bFGF] and ascorbic acid-2-phosphate [AA2P]) media to enhance the overall production of collagen were evaluated, along with their relation to the local fluid flow fields. The resulting TEVCs were statically cultured for 3 weeks, followed by a 3 week dynamic culture period using our organ level bioreactor (Hildebrand et al., ABME, Vol. 32, pp. 1039–49, 2004) under approximated pulmonary artery conditions. Results indicated that supplemented media accelerated collagen formation (∼185% increase in collagen mass/MSC compared to standard media), as well as increasing collagen mass production from 3.90 to 4.43 pg/cell/week from 3 to 6 weeks. Using augmented media, dynamic conditioning increased collagen mass production rate from 7.23 to 13.65 pg/cell/week (88.8%) during the dynamic culture period, along with greater preservation of net DNA. Moreover, when compared to our previous CFF study, organ level conditioning increased the collagen production rate from 4.76 to 6.42 pg/cell/week (35%). Newly conducted CFD studies of the CFF specimen flow patterns suggested that oscillatory surface shear stresses were surprisingly similar to a tri-Leaflet Valve. Overall, we found that the use of simulated pulmonary artery conditions resulted in substantially larger collagen mass production levels and rates found in our earlier CFF study. Moreover, given the fact that the scaffolds underwent modest strains (∼7% max) during either CFF or physiological conditioning, the oscillatory surface shear stresses estimated in both studies may play a substantial role in eliciting MSC collagen production in the highly dynamic engineered heart Valve fluid mechanical environment.

  • The role of organ level conditioning on the promotion of engineered heart Valve tissue development in-vitro using mesenchymal stem cells
    Biomaterials, 2009
    Co-Authors: Sharan Ramaswamy, John E. Mayer, George C Engelmayr, Danielle Gottlieb, David E. Schmidt, Elena Aikawa, Diana M. Gaitan-leon, Virna L. Sales, Michael S Sacks
    Abstract:

    We have previously shown that combined flexure and flow (CFF) augment engineered heart Valve tissue formation using bone marrow-derived mesenchymal stem cells (MSC) seeded on polyglycolic acid (PGA)/poly-L-lactic acid (PLLA) blend nonwoven fibrous scaffolds (Engelmayr, et al., Biomaterials 2006; vol. 27 pp. 6083-95). In the present study, we sought to determine if these phenomena were reproducible at the organ level in a functional tri-Leaflet Valve. Tissue engineered Valve constructs (TEVC) were fabricated using PGA/PLLA nonwoven fibrous scaffolds then seeded with MSCs. Tissue formation rates using both standard and augmented (using basic fibroblast growth factor [bFGF] and ascorbic acid-2-phosphate [AA2P]) media to enhance the overall production of collagen were evaluated, along with their relation to the local fluid flow fields. The resulting TEVCs were statically cultured for 3 weeks, followed by a 3 week dynamic culture period using our organ level bioreactor (Hildebrand et al., ABME, Vol. 32, pp. 1039-49, 2004) under approximated pulmonary artery conditions. Results indicated that supplemented media accelerated collagen formation (approximately 185% increase in collagen mass/MSC compared to standard media), as well as increasing collagen mass production from 3.90 to 4.43 pg/cell/week from 3 to 6 weeks. Using augmented media, dynamic conditioning increased collagen mass production rate from 7.23 to 13.65 pg/cell/week (88.8%) during the dynamic culture period, along with greater preservation of net DNA. Moreover, when compared to our previous CFF study, organ level conditioning increased the collagen production rate from 4.76 to 6.42 pg/cell/week (35%). Newly conducted CFD studies of the CFF specimen flow patterns suggested that oscillatory surface shear stresses were surprisingly similar to a tri-Leaflet Valve. Overall, we found that the use of simulated pulmonary artery conditions resulted in substantially larger collagen mass production levels and rates found in our earlier CFF study. Moreover, given the fact that the scaffolds underwent modest strains (approximately 7% max) during either CFF or physiological conditioning, the oscillatory surface shear stresses estimated in both studies may play a substantial role in eliciting MSC collagen production in the highly dynamic engineered heart Valve fluid mechanical environment.

  • Engineered Heart Valve Tissue Formation at the Organ Level: Effects of Flow Dynamics on Tissue Development
    ASME 2008 Summer Bioengineering Conference Parts A and B, 2008
    Co-Authors: Sharan Ramaswamy, John E. Mayer, Danielle Gottlieb, Michael S Sacks
    Abstract:

    Tissue engineered heart Valve (TEHV) development protocols have yet to be optimized to an extent that can offer long-term function of value to patients, beyond contemporary clinical practices. One method of optimization may be possible through appropriate mechanical conditioning of the evolving engineered tissue before implantation. Engelmayr et al. [1] showed the synergistic benefits of combined flexural and fluid induced stresses on valvular-like tissue grown on rectangular scaffold strips. However, for clinical translation to be realized, it is important to determine if the nature of extracellular matrix production in such mechanistic studies also occurs at the macro-level, in the intact tri-Leaflet Valve geometry. Therefore, appropriate organ-level studies are required wherein the valvular tissues are subjected to the complex 3-dimensional flow/flexure/stretch regimes under highly controlled sub-, normal, and hyper-physiological flow levels. In this manner, biomechanical factors contributing to engineered tissue development can be coupled to tri-Leaflet Valve geometry requirements. In this study, one possible conditioning strategy on tri-Leaflet TEHV structures is presented.Copyright © 2008 by ASME

Qi Yuan - One of the best experts on this subject based on the ideXlab platform.

  • numerical and in vitro experimental assessment of the performance of a novel designed expanded polytetrafluoroethylene stentless bi Leaflet Valve for aortic Valve replacement
    PLOS ONE, 2019
    Co-Authors: Munirah Ismail, Masakazu Nakao, Qi Yuan
    Abstract:

    : The expanded polytetrafluoroethylene (ePTFE) heart Valve can serve as a viable option for prosthetic aortic Valve. In this study, an ePTFE bi-Leaflet Valve design for aortic Valve replacement (AVR) is presented, and the performance of the proposed Valve was assessed numerically and experimentally. The Valve was designed using CAE software. The dynamic behavior of the newly designed bi-Leaflet Valve under time-varying physiological pressure loading was first investigated by using commercial finite element code. Then, in-vitro tests were performed to validate the simulation and to assess the hemodynamic performance of the proposed design. A tri-Leaflet ePTFE Valve was tested in-vitro under the same conditions as a reference. The maximum Leaflet coaptation area of the bi-Leaflet Valve during diastole was 216.3 mm2. When fully closed, no leakage gap was observed and the free edges of the molded Valve formed S-shaped lines. The maximum Von Mises stress during a full cardiac cycle was 4.20 MPa. The dynamic performance of the bi-Leaflet Valve was validated by the in-vitro test under physiological aortic pressure pulse. The effective orifice area (EOA), mean pressure gradient, regurgitant volume, leakage volume and energy loss of the proposed Valve were 3.14 cm2, 8.74 mmHg, 5.93 ml/beat, 1.55 ml/beat and 98.99 mJ, respectively. This study reports a novel bi-Leaflet Valve design for AVR. The performance of the proposed Valve was numerically and experimentally assessed. Compared with the reference Valve, the proposed design exhibited better structural and hemodynamic performances, which improved Valve competency. Moreover, the performance of the bi-Leaflet design is comparable to commercialized Valves available on the market. The results of the present study provide a viable option for the future clinical applications.

  • Numerical and in-vitro experimental assessment of the performance of a novel designed expanded-polytetrafluoroethylene stentless bi-Leaflet Valve for aortic Valve replacement - Fig 13
    2019
    Co-Authors: Guangyu Zhu, Munirah Binte Ismail, Masakazu Nakao, Qi Yuan, Joon Hock Yeo
    Abstract:

    Trans-valvular prssures and aortic flow rates of the (a) bi-Leaflet Valve and (b) reference tri-Leaflet Valve over one cardiac cycle.

  • Numerical and in-vitro experimental assessment of the performance of a novel designed expanded-polytetrafluoroethylene stentless bi-Leaflet Valve for aortic Valve replacement
    2019
    Co-Authors: Munirah Ismail, Qi Yuan, Zhu Guangyu, Nakao Masakazu, Yeo, Joon Hock
    Abstract:

    The expanded polytetrafluoroethylene (ePTFE) heart Valve can serve as a viable option for prosthetic aortic Valve. In this study, an ePTFE bi-Leaflet Valve design for aortic Valve replacement (AVR) is presented, and the performance of the proposed Valve was assessed numerically and experimentally. The Valve was designed using CAE software. The dynamic behavior of the newly designed bi-Leaflet Valve under time-varying physiological pressure loading was first investigated by using commercial finite element code. Then, in-vitro tests were performed to validate the simulation and to assess the hemodynamic performance of the proposed design. A tri-Leaflet ePTFE Valve was tested in-vitro under the same conditions as a reference. The maximum Leaflet coaptation area of the bi-Leaflet Valve during diastole was 216.3 mm2. When fully closed, no leakage gap was observed and the free edges of the molded Valve formed S-shaped lines. The maximum Von Mises stress during a full cardiac cycle was 4.20 MPa. The dynamic performance of the bi-Leaflet Valve was validated by the in-vitro test under physiological aortic pressure pulse. The effective orifice area (EOA), mean pressure gradient, regurgitant volume, leakage volume and energy loss of the proposed Valve were 3.14 cm2, 8.74 mmHg, 5.93 ml/beat, 1.55 ml/beat and 98.99 mJ, respectively. This study reports a novel bi-Leaflet Valve design for AVR. The performance of the proposed Valve was numerically and experimentally assessed. Compared with the reference Valve, the proposed design exhibited better structural and hemodynamic performances, which improved Valve competency. Moreover, the performance of the bi-Leaflet design is comparable to commercialized Valves available on the market. The results of the present study provide a viable option for the future clinical applications.NMRC (Natl Medical Research Council, S’pore)Published versio

Wenbo Zhang - One of the best experts on this subject based on the ideXlab platform.

  • isogeometric finite element based simulation of the aortic heart Valve integration of neural network structural material model and structural tensor fiber architecture representations
    International Journal for Numerical Methods in Biomedical Engineering, 2021
    Co-Authors: Wenbo Zhang, Giovanni Rossini, David Kamensky, Tan Buithanh, Michael S Sacks
    Abstract:

    The functional complexity of native and replacement aortic heart Valves are well known, incorporating such physical phenomenons as time-varying non-linear anisotropic soft tissue mechanical behavior, geometric non-linearity, complex multi-surface time varying contact, and fluid-structure interactions to name a few. It is thus clear that computational simulations are critical in understanding AV function and for the rational basis for design of their replacements. However, such approaches continued to be limited by ad-hoc approaches for incorporating tissue fibrous structure, high-fidelity material models, and Valve geometry. To this end, we developed an integrated tri-Leaflet Valve pipeline built upon an isogeometric analysis (IGA) framework. A high-order structural tensor (HOST) based method was developed for efficient storage and mapping the two-dimensional fiber structural data onto the valvular 3D geometry. We then developed a neural network (NN) material model that learned the responses of a detailed mesostructural model for exogenously cross-linked planar soft tissues. The NN material model not only reproduced the full anisotropic mechanical responses but also demonstrated a considerable efficiency improvement, as it was trained over a range of realizable fibrous structures. Results of parametric simulations were then performed, as well as population based bicuspid aortic heart Valve fiber structure, that demonstrated the efficiency and robustness of the present approach. In summary, the present approach that integrates HOST and NN material model provides an efficient computational analysis framework with increased physical and functional realism for the simulation of native and replacement tri-Leaflet heart Valves. This article is protected by copyright. All rights reserved.

  • Isogeometric finite element‐based simulation of the aortic heart Valve: Integration of neural network structural material model and structural tensor fiber architecture representations
    International journal for numerical methods in biomedical engineering, 2021
    Co-Authors: Wenbo Zhang, Giovanni Rossini, David Kamensky, Tan Bui-thanh, Michael S Sacks
    Abstract:

    The functional complexity of native and replacement aortic heart Valves are well known, incorporating such physical phenomenons as time-varying non-linear anisotropic soft tissue mechanical behavior, geometric non-linearity, complex multi-surface time varying contact, and fluid-structure interactions to name a few. It is thus clear that computational simulations are critical in understanding AV function and for the rational basis for design of their replacements. However, such approaches continued to be limited by ad-hoc approaches for incorporating tissue fibrous structure, high-fidelity material models, and Valve geometry. To this end, we developed an integrated tri-Leaflet Valve pipeline built upon an isogeometric analysis (IGA) framework. A high-order structural tensor (HOST) based method was developed for efficient storage and mapping the two-dimensional fiber structural data onto the valvular 3D geometry. We then developed a neural network (NN) material model that learned the responses of a detailed mesostructural model for exogenously cross-linked planar soft tissues. The NN material model not only reproduced the full anisotropic mechanical responses but also demonstrated a considerable efficiency improvement, as it was trained over a range of realizable fibrous structures. Results of parametric simulations were then performed, as well as population based bicuspid aortic heart Valve fiber structure, that demonstrated the efficiency and robustness of the present approach. In summary, the present approach that integrates HOST and NN material model provides an efficient computational analysis framework with increased physical and functional realism for the simulation of native and replacement tri-Leaflet heart Valves. This article is protected by copyright. All rights reserved.

Pierre Gianello - One of the best experts on this subject based on the ideXlab platform.

  • cormatrix Valved conduit in a porcine model long term remodelling and biomechanical characterization
    Interactive Cardiovascular and Thoracic Surgery, 2017
    Co-Authors: Zahra Mosala Nezhad, Laurent De Kerchove, Caroline Fervaille, Xavier Bollen, Jeanpaul Dehoux, Gebrine El Khoury, Alain Poncelet, Xavier Banse, Pierre Gianello
    Abstract:

    OBJECTIVES: Porcine small intestinal submucosa extracellular matrix (CorMatrix; CorMatrix Cardiovascular, Rosewell, GA) is a relatively novel tissue substitute used in cardiovascular applications. We investigated the biological reaction and remodelling of CorMatrix as a tri-Leaflet Valved conduit in a pig model. We hypothesized that CorMatrix maintains a durable architecture as a Valved conduit and remodels to resemble surrounding tissues. METHODS: We fashioned the Valved conduit using a 7 × 10 cm 4-ply CorMatrix sheet and placed it in the thoracic aorta of seven landrace pigs for 3, 4, 5 and 6 months. Biodegradation, replacement by native tissue, strength and durability were examined by histology, immunohistochemistry and mechanical testing. RESULTS: Four pigs, one per time frame, completed the study. The conduit lost its original architecture as a tri-Leaflet Valve due to cusp immobility, subsequent attachment to the wall segment and consequent maintenance of a thick arterial wall-like structure. Scaffold resorption was incomplete, with disorganized inconsistent spatial and temporal degradation even at 6 months. Fibrosis, scarring and calcification started at 4 months and chronic inflammation persisted. The partially remodelled scaffold did not resemble the aortic wall, suggesting impaired remodelling. Mechanical testing showed progressive weakening of the tissues over time, which were liable to breakage. CONCLUSIONS: CorMatrix is biodegradable; however, it failed to remodel in a structured and anatomical fashion in an arterial environment. Progressive mechanical and remodelling failure in this scenario might be explained by the complexity of the conduit design and the host's chronic inflammatory response, leading to early fibrosis and calcification.

  • CRT-500.03 Examining the Remodeling of CorMatrix as a TriLeaflet Valve Conduit in Heterotopic Position in Growing Pig Model
    JACC: Cardiovascular Interventions, 2016
    Co-Authors: Zahra Mosala Nezhad, Laurent De Kerchove, Caroline Fervaille, Jeanpaul Dehoux, Alain Poncelet, Xavier Boullin, Gebrine Elkhoury, Pierre Gianello
    Abstract:

    Porcine small intestinal submucosa extracellular matrix, CorMatrix (CorMatrix Cardiovascular, Roswell, GA) is potentially suitable tissue substitute for cardiovascular use. We investigate the biological reaction and remodeling of CorMatrix, as a tri-Leaflet Valve conduit in growing pig model. We