Tricuspidization by the raphe suspension technique in a unicuspid or bicuspid aortic valve

Central plication to close a raphe is the most reproducible procedure in bicuspid aortic valve or unicuspid aortic valve repair; however, raphe plication is sometimes associated with systolic doming of the fused leaflet and narrowing of the valve orifice. We experienced a patient with a bicuspid aortic valve with a pliable raphe and commissure orientation close to 120°. Suspension of the raphe was performed instead of plication to create a functional commissure and achieve tricuspidization. This raphe suspension technique could be used in a patient with a unicuspid aortic valve to reconstruct a functional left lateral commissure concomitant with anterior neocommissure reconstruction using pericardium. This simple raphe suspension technique may be beneficial for some patients to avoid excessive plication.

Gender differences in the dimensions of tricuspid valve orifice and leaflets in the Bangladeshi population - a morphometric study

Background: The present study aims to measure the circumference, length, and breadth of thedifferent leaflets of the tricuspid valve orifice in men and women to enable improved treatmentand management for cardiac patients in future. Materials and methods: In this cross-sectionalstudy, samples of the cadaveric heart (41 male, 19 female, and age ranging between 20 and70 years) were collected within 12–24 hours of death from unclaimed dead bodies that wereautopsied in the morgues of Sir Salimullah Medical College (SSMC) and Dhaka Medical College(DMC), Dhaka, Bangladesh. Unpaired t-test was conducted to determine significant genderdifferences using SPSS 16. Results: There were no significant difference in the circumference,length, and breadth of the anterior, posterior, and septal leaflets of tricuspid valves between menand women. Conclusion :The circumference, length, and breadth of the anterior, posterior,and septal leaflets of tricuspid valves are similar between men and women in the Bangladeshipopulation. Therefore, there will be no specific difference in the surgical and therapeutictreatment for men and women. Bangladesh Journal of Medical Science Vol.20(2) 2021 p.342-347

Abstract 12568: Impact of Aortic Stenosis on Myofiber Stress: Translational Application of Left Ventricle-Aortic Coupling Simulations

Introduction: Grading aortic stenosis (AS) has traditionally relied on measuring hemodynamic parameters of transvalvular pressure gradient, ejection jet velocity, or estimating valve orifice area. Recent research has highlighted limitations of these criteria at effectively grading AS in presence of left ventricle (LV) dysfunction. We hypothesize that simulations coupling the aorta and LV will provide meaningful insight into myocardial biomechanical derangements that accompany AS. Reference data from the normal ventricle should first be obtained. Methods: A multi-domain cardiac model with representative anatomy and material properties was used to create AS simulations. Finite element analysis was performed with ABAQUS FEA®. An anisotropic hyperelastic model was assigned to the aorta and LV passive properties, while time-varying elastance function governed LV active response. Mild and severe AS were created by restricting the aortic valve orifice area. Results: Global LV myofiber end systolic (ES) stress (mean±SD) was 9.31±10.33 kPa at baseline (no AS), 13.13±10.29 kPa for mild AS, and 16.18±10.59 kPa with severe AS. Mean LV myofiber ES strains were -22.4±8.7%, -22.2±8.9%, and -21.9±9.2%, respectively. Mild and severe AS had significant stress elevation compared to baseline (mild AS vs base; p<0.01, severe AS vs base; p<0.001) and when compared to each other (p<0.01). See Figure 1 . Ventricular regions that experienced greatest magnitude ES stress were (severe AS vs baseline) basal inferior (39.87±14.73 vs 30.02±12.08 kPa; p<0.01), mid-anteroseptal (32.29±11.56 vs 24.79±12.00 kPa; p<0.001), and apex (27.99±8.44 vs 23.52±10.19 kPa; p<0.001). Conclusions: Isolated AS in a normal heart was simulated, and significantly elevated LV myofiber stress was quantified. This data serves as a comparison to future studies that will incorporate patient-specific ventricular geometries and material parameters, aiming to correlate LV biomechanics to AS severity.

Optimization Algorithm and Joint Simulation to Micro Thermal Deformation Using Temperature Measurement in the Orifice of Hydraulic Valve

When exposed to viscous heating, hydraulic valve orifices experience thermal deformation, which causes spool clamping and actuator disorder. Quantitative research on thermal deformation can help reveal the micro-mechanism of spool clamping. In this study, miniature thermocouples are embedded into a valve orifice with an opening size of 1 mm to measure temperature distribution. An optimization algorithm based on measurement data (M-OA) for the thermal deformation of the valve orifice is proposed. The temperature and thermal deformation of the valve orifice are calculated through Fluent and Workbench joint simulation, with the measurement data serving as boundary conditions. Results show that, for a valve orifice with a valve wall length of 18 mm, when the temperature of the sharp edge is at 60 °C, thermal deformation measures 7.7 μm via observation and 7.62803 μm via M-OA, indicating that the M-OA method is reliable. The results of the joint simulation can be accepted because measurements of temperature reached an accuracy rate of 95%, and that of deformation reached 82.7%. A large drop in pressure led to a rapid increase in temperature, causing serious thermal deformation of the valve orifice. With an inlet pressure of 3 MPa, the temperature of the sharp edge reached 72.9 °C within 110 min, and radial thermal deformation can reach 8.3 μm. Such deformation poses great risk of spool clamping for a spool valve of Φ36 mm.