The Design, Fabrication and Evaluation of a Trileaflet Prosthetic Heart Valve

1980 ◽  
Vol 102 (1) ◽  
pp. 34-41 ◽  
Author(s):  
G. E. Chetta ◽  
J. R. Lloyd
Keyword(s):  
Heart Valve ◽  
Performance Index ◽  
Test Section ◽  
Heart Valves ◽  
Prosthetic Heart Valve ◽  
Prosthetic Heart Valves ◽  
In Vitro Evaluation ◽  
Design Considerations ◽  
Evaluation Techniques

Although prosthetic heart valves have been in existence for many years, the need for new improved designs and in-vitro evaluation techniques are apparent. This paper presents details on the design considerations, fabrication techniques and heart valve evaluation equipment. A valve performance index is discussed in light of various valve and mock circulatory test section designs. The need for national and indeed international valve evaluation techniques is made apparent.

Simulations of the Hinge Flow Fields of a Bileaflet Mechanical Heart Valve Under Physiologic Pulsatile Aortic Conditions

2008 ◽  
Author(s):  
Hélène A. Simon ◽  
Liang Ge ◽  
Iman Borazjani ◽  
Fotis Sotiropoulos ◽  
Ajit P. Yoganathan
Keyword(s):  
Heart Valve ◽  
Heart Valves ◽  
Mechanical Heart Valve ◽  
Prosthetic Heart Valve ◽  
Prosthetic Heart Valves ◽  
Valve Design ◽  
Bileaflet Mechanical Heart Valve ◽  
Hinge Flow ◽  
Blood Elements

Native heart valves with limited functionality are commonly replaced by prosthetic heart valves. Since the first heart valve replacement in 1960, more than three million valves have been implanted worldwide. The most widely implanted prosthetic heart valve design is currently the bileaflet mechanical heart valve (BMHV), with more than 130,000 implants every year worldwide. However, studies have shown that this valve design can still cause major complications, including hemolysis, platelet activation, and thromboembolic events. Clinical reports and recent in vitro experiments suggest that these thrombogenic complications are associated with the hemodynamic stresses imposed on blood elements by the complex non-physiologic flow induced by the valve, in particular in the hinge region.

scholarly journals Hemodynamic Performance of Dysfunctional Prosthetic Heart Valve with the Concomitant Presence of Subaortic Stenosis: In Silico Study

2020 ◽  
Vol 7 (3) ◽  
pp. 90
Author(s):  
Othman Smadi ◽  
Anas Abdelkarim ◽  
Samer Awad ◽  
Thakir D. Almomani
Keyword(s):  
Early Detection ◽  
Heart Valve ◽  
Heart Valves ◽  
Cfd Simulation ◽  
Treatment Plan ◽  
Mechanical Heart Valve ◽  
Prosthetic Heart Valve ◽  
Subaortic Stenosis ◽  
Prosthetic Heart Valves ◽  
The Impact

The prosthetic heart valve is vulnerable to dysfunction after surgery, thus a frequent assessment is required. Doppler electrocardiography and its quantitative parameters are commonly used to assess the performance of the prosthetic heart valves and provide detailed information on the interaction between the heart chambers and related prosthetic valves, allowing early detection of complications. However, in the case of the presence of subaortic stenosis, the accuracy of Doppler has not been fully investigated in previous studies and guidelines. Therefore, it is important to evaluate the accuracy of the parameters in such cases to get early detection, and a proper treatment plan for the patient, at the right time. In the current study, a CFD simulation was performed for the blood flow through a Bileaflet Mechanical Heart Valve (BMHV) with concomitant obstruction in the Left Ventricle Outflow Tract (LVOT). The current study explores the impact of the presence of the subaortic on flow patterns. It also investigates the accuracy of (BMHV) evaluation using Doppler parameters, as proposed in the American Society of Echocardiography (ASE) guidelines.

Modeling of Tissue Fatigue Damage in Bio-Prosthetic Heart Valve

2011 ◽  
Author(s):  
Caitlin Martin ◽  
Wei Sun
Keyword(s):  
Fatigue Damage ◽  
Heart Valve ◽  
Anticoagulant Therapy ◽  
Heart Valves ◽  
Prosthetic Heart Valve ◽  
Bovine Pericardium ◽  
Prosthetic Heart Valves ◽  
Mechanical Valves ◽  
In Vivo Degradation

Bio-prosthetic heart valves (BHVs) with leaflets made of glutaraldehyde-treated bovine pericardium (GLBP), have been used extensively to replace diseased heart valves. BHVs display superior hemodynamics to mechanical valves and eliminate the need for anticoagulant therapy; however, they exhibit poor durability resulting from in vivo degradation and fatigue damage of the leaflets.

Research Contribution of Prosthetic Valve Manufacturers Interfacing Academic-Industry Research Efforts

1999 ◽  
Author(s):  
Xiao Gong ◽  
Yi-Ren Woo ◽  
Ajit P. Yoganathan ◽  
Andreas Anayiotos
Keyword(s):  
Heart Valve ◽  
Heart Valves ◽  
Clinical Performance ◽  
Thrombus Formation ◽  
Academic Research ◽  
Prosthetic Heart Valve ◽  
Structural Safety ◽  
Prosthetic Heart Valves ◽  
Implantable Medical Device ◽  
Valve Design

Abstract Prosthetic heart valve is one of the most successful implantable medical devices. However, introducing better performing and longer lasting prosthetic mechanical heart valves (MHV) into clinical use has been slow because predicting the long term performance of a new valve design is difficult. Although significant progresses in many scientific fronts relevant to prosthetic heart valve development have been achieved, we still have an imperfect understanding of host responses to an implantable medical device and incomplete knowledge in associating hemodynamic characteristics of a valve design to clinical performance. Valve designers, frequently need to over design the valve components to ensure structural safety and thus, sacrifice the opportunity to optimize performance. Complications such as infection, thrombus formation, thromboembolic incidents, and hemorrhage associated to the use of prosthetic valves are still reported and valve designers are working hard to eliminate them. Further advancing scientific knowledge in designing and evaluating prosthetic heart valves is of great interest to many Valve designers and manufacturers. Interfacing Industry and Academic research efforts has been thwarted due to predominantly proprietary issues. Considering the benefits of a better performing MHV to the patients, this industry session will bring researchers from various MHV companies and academic institutions to discuss how to share the results of scientific studies more effectively. This will help accelerate new MHV development without compromising the confidentiality of key valve design information. The issue of standardized MHV testing will also be addressed.

Impact of prosthetic heart valves on pregnancy in Bangladeshi women

Perfusion ◽  
2019 ◽  
Vol 34 (6) ◽  
pp. 446-452 ◽  
Author(s):  
Redoy Ranjan ◽  
Dipannita Adhikary ◽  
Sanjoy Kumar Saha ◽  
Sabita Mandal ◽  
Kamrul Hasan ◽  
...  
Keyword(s):  
Pregnancy Outcome ◽  
Heart Valve ◽  
Heart Valves ◽  
Prosthetic Heart Valve ◽  
Study Groups ◽  
Prosthetic Heart Valves ◽  
Group I ◽  
Mechanical Prostheses ◽  
Warfarin Embryopathy ◽  
Group Ii

Background: This study evaluated pregnancy outcome in women with a prosthetic heart valve, especially with the oral anticoagulation therapy that must be weighed against the risk of intracardiac thrombosis. Methods: This multicenter, retrospective, cohort study was undertaken between January 2012 and June 2017. The principal maternal outcome variables included bleeding and thromboembolic complications, infective endocarditis, prosthetic valve thrombosis and heart failure. However, the main foetal outcome variables included miscarriage, mortality, preterm baby, warfarin embryopathy, low birthweight and the mode of delivery. Results: A total of 265 pregnancies in women with prosthetic heart valves were evaluated in two groups: Group I (n = 182) covers a mechanical valve, while Group II (n = 82) covers a bioprosthetic valve. The mean age of the patients was 25.2 ± 2.5 years and 24.5 ± 5.2 years in Group I and Group II, respectively. Approximately 80% of the patients had normal echocardiography findings. However, Group I (mechanical prostheses) has a higher incidence (11.54%) of thrombus formation in comparison with the bioprostheses. Hemorrhagic complications and spontaneous miscarriage were statistically significant (p⩽0.05) between the study groups. However, normal pregnancy outcome (91.57%) was significantly higher (p⩽0.05) in Group II compared to Group I (61.54%). Mean birthweight and mean APGAR score were found normal in both study groups. Only 2.75% of patients have warfarin embryopathy in Group I. Furthermore, comparison of SF-36 scores for HRQOL (Health-Related Quality of Life) before and after pregnancy were statistically insignificant among the study population. Conclusion: Proper antenatal care and early risk stratification are the fundamental measures to improve the maternal and foetal outcomes in a patient with a prosthetic heart valve.

A Method for Real-Time In Vitro Observation of Cavitation on Prosthetic Heart Valves

1994 ◽  
Vol 116 (4) ◽  
pp. 460-468 ◽  
Author(s):  
Conrad M. Zapanta ◽  
Edward G. Liszka ◽  
Theodore C. Lamson ◽  
David R. Stinebring ◽  
Steve Deutsch ◽  
...  
Keyword(s):  
Real Time ◽  
Heart Valve ◽  
Cavity Growth ◽  
Prosthetic Heart Valve ◽  
Aortic Pressure ◽  
Atrial Pressure ◽  
Prosthetic Heart Valves ◽  
Distilled Water ◽  
Beat Rate

A method for real-time in vitro observation of cavitation on a prosthetic heart valve has been developed. Cavitation of four blood analog fluids (distilled water, aqueous glycerin, aqueous polyacrylamide, and aqueous xanthan gum) has been documented for a Medtronic/Hall™ prosthetic heart valve. This method employed a Penn State Electrical Ventricular Assist Device in a mock circulatory loop that was operated in a partial filling mode associated with reduced atrial filling pressure. The observations were made on a valve that was located in the mitral position, with the cavitation occurring on the inlet side after valve closure on every cycle. Stroboscopic videography was used to document the cavity life cycle. Bubble cavitation was observed on the valve occluder face. Vortex cavitation was observed at two locations in the vicinity of the valve occluder and housing. For each fluid, cavity growth and collapse occurred in less than one millisecond, which provides strong evidence that the cavitation is vaporous rather than gaseous. The cavity duration time was found to decrease with increasing atrial pressure at constant aortic pressure and beat rate. The area of cavitation was found to decrease with increasing delay time at a constant aortic pressure, atrial pressure, and beat rate. Cavitation was found to occur in each of the fluids, with the most cavitation seen in the Newtonian fluids (distilled water and aqueous glycerin).

Fluid Stresses in the Vicinity of Disk, Ball, and Tilting Disk Prosthetic Heart Valves From In-Vitro Measurements

1977 ◽  
Vol 99 (4) ◽  
pp. 173-177 ◽  
Author(s):  
R. S. Figliola ◽  
T. J. Mueller
Keyword(s):  
Heart Valves ◽  
High Stress ◽  
Test Chamber ◽  
Prosthetic Heart Valve ◽  
Separated Flow ◽  
Reynolds Numbers ◽  
Prosthetic Heart Valves ◽  
In Vitro Measurements ◽  
Turbulence Data

Experiments were conducted in a steady flow test apparatus with an axisymmetric aortic shaped test chamber using hot-wire anemometry to obtain local momentum transfer and turbulence data in the vicinity of the model disk, Kay-Shiley disk, Starr-Edwards ball and Bjork-Shiley tilting disk prosthetic heart valve configurations. These data for Reynolds numbers of 2000, 4000, and 6000 were used to locate regions of high stress where erythrocytes may be lysed or severely strained. Nondimensionalized velocity profiles downstream of the valves indicated a similarity of behavior for all Reynolds numbers at an axial location. Velocity gradients of magnitudes potentially damaging to erythrocytes were found. These gradients were largest for disk-type occluders. Large regions of separated flow were found to occur behind the valve sewing ring, distal to the valve occluder, and along the test chamber wall distal to the valve for all valves tested. Relatively high turbulence was found to exist distal to all valves tested. Turbulent stresses of magnitudes potentially hemolytic were measured.

Sign in / Sign up

Export Citation Format

Share Document