On-X Valve

Chaudhary, Rahul; Garg, Jalaj; Krishnamoorthy, Parasuram; Shah, Neeraj; Feldman, DO Bruce; Martinez, Matthew W.; Freudenberger, Ronald S

doi:10.1097/crd.0000000000000105

Cited by 29 publications

(5 citation statements)

References 32 publications

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“…Finally, this case raises the importance of re-evaluating patients who are having difficulty maintaining a therapeutic INR with coumadin or who have had embolic events secondary to mechanical valves. Although patients with On-X valves are allowed a lower INR of 1.5-2.0 for improved cumulative endpoints of thombogenic and bleeding events [ 11 ], these valves have increased thrombogenicity overall [ 2 ].…”

Section: Discussionmentioning

confidence: 99%

Critical Limb Ischemia in a Young Patient With a Mechanical Aortic Valve Leading to Bilateral Above-Knee Amputation

Kamath¹,

Ulhaque²,

Ali³

et al. 2021

Cureus

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This case reports a 24-year-old female with prior aortic insufficiency who underwent a mechanical aortic valve replacement with subsequent transient ischemic attacks and documented subtherapeutic international normalized ratio (INR). She presented with pain and bilateral lower extremity pulselessness. Workup showed a supratherapeutic INR, no thrombus on echocardiogram, and computed tomography angiography demonstrating no flow in the bilateral common femoral arteries. Patient failed repeated thrombectomies and had a bilateral above-knee amputation. The patient was suspected to have acute on chronic emboli from the mechanical aortic valve and further testing did not elucidate contributory causes of her critical limb ischemia. We believe this is the first documented case of bilateral lower extremity ischemia due to mechanical valve complications.

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Section: Discussionmentioning

confidence: 99%

Critical Limb Ischemia in a Young Patient With a Mechanical Aortic Valve Leading to Bilateral Above-Knee Amputation

Kamath¹,

Ulhaque²,

Ali³

et al. 2021

Cureus

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“…The AV cylinder translates sinusoidally to push blood into the ventricle, increasing ventricular pressure, which in turn moves blood through the aortic valve and through the conduit outlet. The valves are ON-X BMHVs, which use an actuated pivot mechanism to allow for an opening angle of up to which promotes laminar flow, resulting in improved haemodynamics, a reduction in haemolysis and thrombogenicity 41 .…”

Section: Methodsmentioning

confidence: 99%

Fluid–structure interaction modelling of a positive-displacement Total Artificial Heart

Bornoff

Najar²,

Fresiello

et al. 2023

Sci Rep

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For those suffering from end-stage biventricular heart failure, and where a heart transplantation is not a viable option, a Total Artificial Heart (TAH) can be used as a bridge to transplant device. The Realheart TAH is a four-chamber artificial heart that uses a positive-displacement pumping technique mimicking the native heart to produce pulsatile flow governed by a pair of bileaflet mechanical heart valves. The aim of this work was to create a method for simulating haemodynamics in positive-displacement blood pumps, using computational fluid dynamics with fluid–structure interaction to eliminate the need for pre-existing in vitro valve motion data, and then use it to investigate the performance of the Realheart TAH across a range of operating conditions. The device was simulated in Ansys Fluent for five cycles at pumping rates of 60, 80, 100 and 120 bpm and at stroke lengths of 19, 21, 23 and 25 mm. The moving components of the device were discretised using an overset meshing approach, a novel blended weak–strong coupling algorithm was used between fluid and structural solvers, and a custom variable time stepping scheme was used to maximise computational efficiency and accuracy. A two-element Windkessel model approximated a physiological pressure response at the outlet. The transient outflow volume flow rate and pressure results were compared against in vitro experiments using a hybrid cardiovascular simulator and showed good agreement, with maximum root mean square errors of 15% and 5% for the flow rates and pressures respectively. Ventricular washout was simulated and showed an increase as cardiac output increased, with a maximum value of 89% after four cycles at 120 bpm 25 mm. Shear stress distribution over time was also measured, showing that no more than $$4.5\times 10^{-4}$$ 4.5 × 10 - 4 % of the total volume exceeded 150 Pa at a cardiac output of 7 L/min. This study showed this model to be both accurate and robust across a wide range of operating points, and will enable fast and effective future studies to be undertaken on current and future generations of the Realheart TAH.

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“…In recent years, the newer generation On-X bileaflet valve has increasingly been implanted, most commonly in the aortic position. Its improved structural material devoid of silicon and improved engineering have led to improved fluid dynamics and reduced thrombogenicity [ 12 , 13 ]. Echocardiographically, however, the On-X would essentially appear similar to a standard SJM Regent valve, as their structural differences are not substantial enough to allow for visual differentiation.…”

Section: Echocardiographic Assessment: General Features Of Prosthetic...mentioning

confidence: 99%

Echocardiographic Assessment of Prosthetic Valves

Ashraf¹,

Freeman²

2022

Rev. Cardiovasc. Med.

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Prosthetic valves are increasingly encountered in clinical practice. A grasp of the intricacies of the assessment and management of prosthetic valves is thus a crucial skillset for the practicing cardiologist. Echocardiography is the imaging modality of choice for the anatomic and functional evaluation of prosthetic valve. This document reviews the general features of prosthetic valves, echocardiographic identification of normally functioning and dysfunctional prosthetic valves as well as echocardiographic diagnosis of specific prosthetic valvular abnormalities.

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On-X Valve

Cited by 29 publications

References 32 publications

Critical Limb Ischemia in a Young Patient With a Mechanical Aortic Valve Leading to Bilateral Above-Knee Amputation

Critical Limb Ischemia in a Young Patient With a Mechanical Aortic Valve Leading to Bilateral Above-Knee Amputation

Fluid–structure interaction modelling of a positive-displacement Total Artificial Heart

Echocardiographic Assessment of Prosthetic Valves

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