Cardiac Valve Bioreactor for Physiological Conditioning and Hydrodynamic Performance Assessment

Tefft, Brandon J.; Choe, Joshua A.; Young, Melissa; Hennessy, Ryan S.; Morse, David; Bouchard, Jeffery A.; Hedberg, Herbert J.; Consiglio, Joseph F.; Dragomir-Daescu, Dan; Simari, Robert D.; Lerman, Amir

doi:10.1007/s13239-018-00382-2

Cited by 12 publications

(6 citation statements)

References 35 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…All three parameters are important indicators for the clinical assessment of aortic valve stenosis severity 28,[59][60][61] . Although the baseline hydrodynamic performances of unimplanted BHV in pulse simulators have been repeatedly reported [62][63][64] , to the best of our knowledge, we are the first to evaluate the hydrodynamic performances of BHV following in vitro incubations that simulate AGE formation observed in clinical explants. In general, all in vitro incubation conditions resulted in a steady decline in EOA and increases in pressure gradients and peak jet velocities.…”

Section: Discussionmentioning

confidence: 98%

Glycation and Serum Albumin Infiltration Contribute to the Structural Degeneration of Bioprosthetic Heart Valves

Frasca

Xue

Kossar

et al. 2020

Preprint

View full text Add to dashboard Cite

Background: Bioprosthetic heart valves (BHV) are widely used to treat heart valve disease but are fundamentally limited by structural valve degeneration (SVD). Non-calcific mechanisms of SVD entirely account for approximately 30% of SVD cases and contribute to calcific SVD but remain understudied. Glycation mechanisms have not been previously associated with SVD, despite being established as degenerative in collagenous native tissues. Objectives:To determine whether blood component infiltration-based glycation and concomitant human serum albumin (HSA) deposition contribute mechanistically to SVD.Methods: Immunohistochemistry (IHC) was used to identify advanced glycation end-products (AGEs) and serum albumin accumulation in 45 aortic valve BHV explanted due to SVD, glutaraldehyde-treated bovine pericardium (BP) incubated in vitro in glyoxal and HSA, and rat subcutaneous BP implants. Structural impacts of glycation-related mechanisms were evaluated by second harmonic generation (SHG) collagen imaging. Hydrodynamic effects of valve glycation and concomitant HSA exposure were studied with an ISO-5840-compliant pulse duplicator system using surgical grade BHV.Results: All 45 clinical explants and in vitro-incubated BP demonstrated accumulated AGE and HSA compared to un-implanted, un-exposed BHV. SHG revealed instigation of collagen malalignment similar to that in SVD explants by glycation and HSA infiltration. Rat subdermal explants also showed AGE and serum albumin accumulation. Pulse duplication demonstrated significantly reduced orifice area and increased pressure gradient and peak fluid velocity following glyoxal and HSA incubations. Conclusions:Glycation and concomitant HSA infiltration occur in clinical BHV and contribute to structural and functional degeneration of leaflet tissue, thus representing novel, interacting mechanisms of BHV SVD.

show abstract

Section: Discussionmentioning

confidence: 98%

Glycation and Serum Albumin Infiltration Contribute to the Structural Degeneration of Bioprosthetic Heart Valves

Frasca

Xue

Kossar

et al. 2020

Preprint

View full text Add to dashboard Cite

show abstract

“…A schematic of the flow chamber is shown in Figure 4. Test chambers with similar geometry are seen in valve testing devices [56] and standards [23], and have been shown to be sufficient for valve testing in in vitro experiments [45,44,55,37,11]. The domain is divided into 96 × 96 × 192 points for a spatial resolution ∆x = 0.046875 cm in the fluid.…”

Section: Fluid-structure Interactionmentioning

confidence: 99%

A design-based model of the aortic valve for fluid-structure interaction

Kaiser

Shad

Hiesinger

et al. 2021

Biomech Model Mechanobiol

View full text Add to dashboard Cite

This paper presents a new method for modeling the mechanics of the aortic valve, and simulates its interaction with blood. As much as possible, the model construction is based on first principles, but such that the model is consistent with experimental observations. We require that tension in the leaflets must support a pressure, then derive a system of partial differential equations governing its mechanical equilibrium. The solution to these differential equations is referred to as the predicted loaded configuration; it includes the loaded leaflet geometry, fiber orientations and tensions needed to support the prescribed load. From this configuration, we derive a reference configuration and constitutive law. In fluid-structure interaction simulations with the immersed boundary method, the model seals reliably under physiological pressures, and opens freely over multiple cardiac cycles. Further, model closure is robust to extreme hypo-and hypertensive pressures. Then, exploiting the unique features of this model construction, we conduct experiments on reference configurations, constitutive laws, and gross morphology. These experiments suggest the following conclusions, which are directly applicable to the design of prosthetic aortic valves. (i) The loaded geometry, tensions and tangent moduli primarily determine model function. (ii) Alterations to the reference configuration have little effect if the predicted loaded configuration is identical. (iii) The leaflets must have sufficiently nonlinear material response to function over a variety of pressures. (iv) Valve performance is highly sensitive to free edge length and leaflet height. For future use, our aortic valve modeling framework offers flexibility in patient-specific models of cardiac flow.

show abstract

“…None of the studies assessed in this article combined a recellularization component with decellularization in their tissue-engineering technology. Much work is being undertaken to explore the capabilities of tissue-engineered scaffolds that are produced from decellularized xenografts and then recellularized using the future host's autologous cells [23,24,32]. Such a graft is expected to be living and thus have the potential to grow, repair, and remodel in situ [15][16][17][18][19].…”

Section: Discussionmentioning

confidence: 99%

“…In addition, a recent concept being explored in heart valve tissue-engineering is construct recellularization using autologous cells [ 32 ]. In essence, a decellularized construct is repopulated with the recipient’s cells and then conditioned within a bioreactor ahead of surgical implantation [ 23 , 24 ]. None of the studies assessed in this article combined a recellularization component with decellularization in their tissue-engineering technology.…”

Section: Discussionmentioning

confidence: 99%

“…In an attempt to achieve this goal, tissue-engineered heart valves have been designed using various combinations of the following framework: firstly, the genetic material of the xenograft is removed through a decellularization process that produces an acellular connective tissue scaffold upon which host cells are seeded [ 21 , 22 ]. The valve is then conditioned in a bioreactor before surgical implantation [ 23 , 24 ]. It is anticipated that the finished product is a living tissue conduit that meets the requirements of an ideal valve prosthesis.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Clinical performance of decellularized heart valves versus standard tissue conduits: a systematic review and meta-analysis

Waqanivavalagi

Bhat

Ground

et al. 2020

J Cardiothorac Surg

View full text Add to dashboard Cite

Background Valve replacement surgery is the definitive management strategy for patients with severe valvular disease. However, valvular conduits currently in clinical use are associated with significant limitations. Tissue-engineered (decellularized) heart valves are alternative prostheses that have demonstrated promising early results. The purpose of this systematic review and meta-analysis is to perform robust evaluation of the clinical performance of decellularized heart valves implanted in either outflow tract position, in comparison with standard tissue conduits. Methods Systematic searches were conducted in the PubMed, Scopus, and Web of Science databases for articles in which outcomes between decellularized heart valves surgically implanted within either outflow tract position of human subjects and standard tissue conduits were compared. Primary endpoints included postoperative mortality and reoperation rates. Meta-analysis was performed using a random-effects model via the Mantel-Haenszel method. Results Seventeen articles were identified, of which 16 were included in the meta-analysis. In total, 1418 patients underwent outflow tract reconstructions with decellularized heart valves and 2725 patients received standard tissue conduits. Decellularized heart valves were produced from human pulmonary valves and implanted within the right ventricular outflow tract in all cases. Lower postoperative mortality (4.7% vs. 6.1%; RR 0.94, 95% CI: 0.60–1.47; P = 0.77) and reoperation rates (4.8% vs. 7.4%; RR 0.55, 95% CI: 0.36–0.84; P = 0.0057) were observed in patients with decellularized heart valves, although only reoperation rates were statistically significant. There was no statistically significant heterogeneity between the analyzed articles (I2 = 31%, P = 0.13 and I2 = 33%, P = 0.10 respectively). Conclusions Decellularized heart valves implanted within the right ventricular outflow tract have demonstrated significantly lower reoperation rates when compared to standard tissue conduits. However, in order to allow for more accurate conclusions about the clinical performance of decellularized heart valves to be made, there need to be more high-quality studies with greater consistency in the reporting of clinical outcomes.

show abstract

Cardiac Valve Bioreactor for Physiological Conditioning and Hydrodynamic Performance Assessment

Cited by 12 publications

References 35 publications

Glycation and Serum Albumin Infiltration Contribute to the Structural Degeneration of Bioprosthetic Heart Valves

Glycation and Serum Albumin Infiltration Contribute to the Structural Degeneration of Bioprosthetic Heart Valves

A design-based model of the aortic valve for fluid-structure interaction

Clinical performance of decellularized heart valves versus standard tissue conduits: a systematic review and meta-analysis

Contact Info

Product

Resources

About