The First Implantation of the Novel Biological Heart Valve, the Inspiris Resilia Aortic Tissue Valve in Africa

Natural tissue, especially autologous tissue is one of ideal materials for tissue regeneration. Decellularized tissue could be assumed as a second choice because the structure and the mechanical properties are well maintained. Decellularized human tissues, for instance, heart valve, blood vessel, and corium, have already been developed and applied clinically. Nowadays, decellularized porcine tissues are also investigated. These decellularized tissues were prepared by detergent treatment. The detergent washing is easy but sometime it has problems. We have developed the novel decellularization method, which applied the high-hydrostatic pressure (HHP). As the tissue set in the pressurizing chamber is treated uniformly, the effect of the high-hydrostatic pressurization does not depend on the size of tissue. We have reported the HHP decellularization of heart valve, blood vessel, bone, and cornea. Furthermore, HHP treatments are reported to have the ability of the extinction of bacillus and the inactivation of virus. So, the HHP treatment is also expected as the sterilization method. We are investigating efficient processes of decellularization and recellularization of biological tissues to have bioscaffolds keeping intact structure and biomechanical properties. Our recent studies on tissue engineering using HHP decellularized tissue will be reported here.

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Outpatient management of heart valve disease following the COVID-19 pandemic: implications for present and future care

Heart ◽

10.1136/heartjnl-2020-317600 ◽

2020 ◽

Vol 106 (20) ◽

pp. 1549-1554 ◽

Cited By ~ 1

Author(s):

Benoy Nalin Shah ◽

Dominik Schlosshan ◽

Hannah Zelie Ruth McConkey ◽

Mamta Heena Buch ◽

Andrew John Marshall ◽

...

Keyword(s):

Heart Valve ◽

Waiting Times ◽

Severe Disease ◽

Valve Disease ◽

Heart Valve Disease ◽

The Novel ◽

Future Care ◽

Novel Coronavirus

The established processes for ensuring safe outpatient surveillance of patients with known heart valve disease (HVD), echocardiography for patients referred with new murmurs and timely delivery of surgical or transcatheter treatment for patients with severe disease have all been significantly impacted by the novel coronavirus pandemic. This has created a large backlog of work and upstaging of disease with consequent increases in risk and cost of treatment and potential for worse long-term outcomes. As countries emerge from lockdown but with COVID-19 endemic in society, precautions remain that restrict ‘normal’ practice. In this article, we propose a methodology for restructuring services for patients with HVD and provide recommendations pertaining to frequency of follow-up and use of echocardiography at present. It will be almost impossible to practice exactly as we did prior to the pandemic; thus, it is essential to prioritise patients with the greatest clinical need, such as those with symptomatic severe HVD. Local procedural waiting times will need to be considered, in addition to usual clinical characteristics in determining whether patients requiring intervention would be better suited having surgical or transcatheter treatment. We present guidance on the identification of stable patients with HVD that could have follow-up deferred safely and suggest certain patients that could be discharged from follow-up if waiting lists are triaged with appropriate clinical input. Finally, we propose that novel models of working enforced by the pandemic—such as increased use of virtual clinics—should be further developed and evaluated.

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Flow-induced Platelet Activation in a St. Jude Mechanical Heart Valve, a Trileaflet Polymeric Heart Valve, and a St. Jude Tissue Valve

Artificial Organs ◽

10.1111/j.1525-1594.2005.29109.x ◽

2005 ◽

Vol 29 (10) ◽

pp. 826-831 ◽

Cited By ~ 42

Author(s):

Wei Yin ◽

Siobhain Gallocher ◽

Leonard Pinchuk ◽

Richard T. Schoephoerster ◽

Jolyon Jesty ◽

...

Keyword(s):

Heart Valve ◽

Platelet Activation ◽

Mechanical Heart Valve ◽

Tissue Valve

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Is an aortic tissue valve the best choice for young adults?

Journal of Thoracic and Cardiovascular Surgery ◽

10.1016/j.jtcvs.2017.09.062 ◽

2018 ◽

Vol 155 (2) ◽

pp. 533-534 ◽

Cited By ~ 1

Author(s):

Richard J. Shemin

Keyword(s):

Young Adults ◽

Aortic Tissue ◽

Tissue Valve

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In Vivo Evaluation of Composite Polymeric Materials for Potential Application in a Trileaflet Heart Valve

ASME 2008 Summer Bioengineering Conference, Parts A and B ◽

10.1115/sbc2008-192889 ◽

2008 ◽

Author(s):

Qiang Wang ◽

Siobhain L. Gallocher ◽

Amit Datye ◽

Leonard Pinchuk ◽

Richard T. Schoephoerster

Keyword(s):

Heart Valve ◽

Potential Application ◽

Polymeric Materials ◽

Valve Leaflet ◽

The Novel ◽

In Vivo Evaluation ◽

Hemodynamic Performance

The novel trileaflet heart valve that is presently undergoing investigation is a composite design of a proprietary polymer (SIBS), with an embedded fabric. SIBS had been shown to be a biocompatible, oxidatively stable polymer, and by adopting the natural valve leaflet design (reinforcement fabric), the SIBS trileaflet valve has the potential to have outstanding hemodynamic performance, durability, and biocompatibility [1,2].

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A Computational Growth Framework for Biological Tissues: Application to Growth of Aortic Root Aneurysm Repaired by the V-shape Surgery

10.1101/2021.09.30.21264318 ◽

2021 ◽

Author(s):

Hai Dong ◽

Minliang Liu ◽

Tongran Qin ◽

Liang Liang ◽

Bulat Ziganshin ◽

...

Keyword(s):

Aortic Root ◽

Growth Parameters ◽

Optimization Procedure ◽

Biological Tissues ◽

Aortic Aneurysms ◽

Patient Specific ◽

Aortic Tissue ◽

The Novel ◽

Post Surgery

Ascending aortic aneurysms (AsAA) often include the dilatation of sinotubular junction (STJ) which usually leads to aortic insufficiency. The novel surgery of the V-shape resection of the noncoronary sinus, for treatment of AsAA with root ectasia, has been shown to be a simpler procedure compared to traditional surgeries. Our previous study showed that the repaired aortic root aneurysms grew after the surgery. In this study, we developed a novel computational growth framework to model the growth of the aortic root repaired by the V-shape surgery. Specifically, the unified-fiber-distribution (UFD) model was applied to describe the hyperelastic deformation of the aortic tissue. A novel kinematic growth evolution law was proposed based on existing observations that the growth rate is linearly dependent on the wall stress. Moreover, we also obtained patient-specific geometries of the repaired aortic root post-surgery at two follow-up time points (Post1 and Post2) for 5 patients, based on clinical CT images. The novel computational growth framework was implemented into the Abaqus UMAT user subroutine and applied to model the growth of the aortic root from Post1 to Post2. Patient-specific growth parameters were obtained by an optimization procedure. The predicted geometry and stress of the aortic root at Post2 agree well with the in vivo results. The novel computational growth framework and the optimized growth parameters could be applied to predict the growth of repaired aortic root aneurysms for new patients and to optimize repair strategies for AsAA.

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Design of an Ex Vivo Culture System to Investigate the Effects of Shear Stress on Cardiovascular Tissue

Journal of Biomechanical Engineering ◽

10.1115/1.2907753 ◽

2008 ◽

Vol 130 (3) ◽

Cited By ~ 39

Author(s):

Philippe Sucosky ◽

Muralidhar Padala ◽

Adnan Elhammali ◽

Kartik Balachandran ◽

Hanjoong Jo ◽

...

Keyword(s):

Tissue Culture ◽

Shear Stress ◽

Heart Valve ◽

Culture System ◽

Ex Vivo ◽

The Novel ◽

Tissue Culture System ◽

Cardiovascular Tissue ◽

Ex Vivo Tissue ◽

Tissue Specimens

Mechanical forces are known to affect the biomechanical properties of native and engineered cardiovascular tissue. In particular, shear stress that results from the relative motion of heart valve leaflets with respect to the blood flow is one important component of their mechanical environment in vivo. Although different types of bioreactors have been designed to subject cells to shear stress, devices to expose biological tissue are few. In an effort to address this issue, the aim of this study was to design an ex vivo tissue culture system to characterize the biological response of heart valve leaflets subjected to a well-defined steady or time-varying shear stress environment. The novel apparatus was designed based on a cone-and-plate viscometer. The device characteristics were defined to limit the secondary flow effects inherent to this particular geometry. The determination of the operating conditions producing the desired shear stress profile was streamlined using a computational fluid dynamic (CFD) model validated with laser Doppler velocimetry. The novel ex vivo tissue culture system was validated in terms of its capability to reproduce a desired cone rotation and to maintain sterile conditions. The CFD results demonstrated that a cone angle of 0.5deg, a cone radius of 40mm, and a gap of 0.2mm between the cone apex and the plate could limit radial secondary flow effects. The novel cone-and-plate permits to expose nine tissue specimens to an identical shear stress waveform. The whole setup is capable of accommodating four cone-and-plate systems, thus concomitantly subjecting 36 tissue samples to desired shear stress condition. The innovative design enables the tissue specimens to be flush mounted in the plate in order to limit flow perturbations caused by the tissue thickness. The device is capable of producing shear stress rates of up to 650dyncm−2s−1 (i.e., maximum shear stress rate experienced by the ventricular surface of an aortic valve leaflet) and was shown to maintain tissue under sterile conditions for 120h. The novel ex vivo tissue culture system constitutes a valuable tool toward elucidating heart valve mechanobiology. Ultimately, this knowledge will permit the production of functional tissue engineered heart valves, and a better understanding of heart valve biology and disease progression.

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