Prosthetic valves in the pulmonary position

In this thesis the prosthetic heart valve in the pulmonary position has been analyzed. The results in this thesis demonstrate that there is a need for a suitable valve for the pulmonary position, tailored to the physiological circumstances of the right ventricle and the young age of this population. Currently available valve types each have its own limitation that tend to be more prone in the pulmonary position. We have demonstrated that a mechanical prosthetic valve can be a suitable option for pulmonary valve replacement. furthermore, we have demonstrated that the hemodynamic conditions in which the valve is placed influence the functionality of valve. Our results showed that the quality of life of congenital heart disease patients with a prosthetic valve is comparable to the general population. Overall, we can conclude that the use of prosthetic valves in the pulmonary valve is suboptimal, while life expectancy increases and in particular the Quality of Life of patients with a pulmonary prosthetic valve does not seem to be affected

Pulmonary versus aortic pressure behavior of a bovine pericardial valve

Background: The Carpentier Edwards Perimount Magna Ease aortic valvular prosthesis (Edwards Lifesciences, Irvine, Calif) has been among the most frequently and successfully used tissue prosthetic cardiac valves. Furthermore, this prosthesis has been used off-label in the pulmonary position. Until now, there has been a paucity of data regarding the functioning of tissue prosthetic valves under pulmonary conditions. Methods: Using a pulse duplicator, hydrodynamic characteristics of a 21-mm and 25-mm Magna Ease valve were evaluated. Among parameters evaluated were leakage orifice area, closing time (ie, time required to close), and leakage duration. This procedure was performed under different pulmonic pressure conditions (15/5 mm Hg, 28/11 mm Hg, 73/32 mm Hg) and normal aortic pressure (120/80 mm Hg) as a reference. Moving images were obtained using a Phantom MIRO M320S high-speed camera (Vision Research Inc, Wayne, NJ) at 600 frames per second and used to analyze valve area in closed position. Results: Under normal pulmonic conditions (28/11 mm Hg) the leakage orifice area was 0.020 ± 0.012 mm2 for the 21-mm valve and 0.054 ± 0.041 mm2 for the 25-mm valve (P = .03). Hydrodynamic characteristics of the valves differed between pulmonary and aortic testing condition. Valve closing volumes were significantly lower under pulmonary hypotension and normal pulmonary conditions than under normal aortic conditions (P < .05). Conclusions: Under normal pulmonary pressure conditions, the hydrodynamic characteristics of Magna Ease valves are significantly different compared with aortic conditions. Further research is needed to determine whether these results are associated with prosthetic valve failure

Mechanical heart valve prosthesis for the right ventricle

A prosthetic heart valve (11) having a pair of cooperating leaflets (15) mounted in a valve body (13) to alternate between an open position where the flow of blood in a downstream direction is permitted and a closed position where the flow of blood in the reverse direction is counteracted. Pivot member sets at diametrically opposite sides of each leaflet guide the leaflets moving between the open and closed positions, each set including an ear (41) or a recess (141) cooperating with an associated cavity (25) or knob (125) of an interior surface of the valve body. Each ear or recess bounds at least one leaflet passageway (76, 77, 176) through that ear or recess and located spaced from upstream and downstream ends of the ear for allowing flow through that ear and the associated cavity, or through that recess, when the leaflets are in the closed positions

Mechanical heart valve prosthesis for the right ventricle

A prosthetic heart valve (11) having a pair of cooperating leaflets (15) mounted in a valve body (13) to alternate between an open position where the flow of blood in a downstream direction is permitted and a closed position where the flow of blood in the reverse direction is counteracted. Pivot member sets at diametrically opposite sides of each leaflet guide the leaflets moving between the open and closed positions, each set including an ear (41) or a recess (141) cooperating with an associated cavity (25) or knob (125) of an interior surface of the valve body. Each ear or recess bounds at least one leaflet passageway (76, 77, 176) through that ear or recess and located spaced from upstream and downstream ends of the ear for allowing flow through that ear and the associated cavity, or through that recess, when the leaflets are in the closed positions

Influence of Transvalvar Pressure Gradient on Hinge Washing in Closed Mechanical Prosthetic Cardiac Valves Under Pulmonary Pressure Conditions: A Comparative In Vitro Study

OBJECTIVE:: Hinge washing is a crucial factor in the prevention of mechanical prosthetic valvar thrombosis, especially in the pulmonary valve position. The aim of this laboratory study was to determine the relationship between pressure difference and the amount of hinge washing in the closed position, using the pressures that are normal for the right ventricle and pulmonary artery. METHODS:: In an in vitro setting, four different bileaflet mechanical valves were tested for hinge washing in closed position. Based on similarity in inner diameter (range: 20.5-21.4 mm), the following valves were tested: Abbott SJM Regent size 23, Cryolife On-X size 23, LivaNova Carbomedics-R size 25, Medtronic Open Pivot (M-OP)-A size 25. Tests were carried out in a range between 3 and 100 mm Hg pressure difference, using water as a test fluid. The amount of leakage per minute through the closed valve was measured. RESULTS:: All four valves showed an increase in leakage with increasing transvalvar gradient, and the relationship between pressure and leakage behaves in logarithmic fashion. Leakage under normal pulmonary diastolic pressure conditions (10 mm Hg) was between 23.3% and 29.3% of the leakage under aortic diastolic pressure conditions (80 mm Hg). The Cryolife On-X valve showed the highest closed leakage volume under pulmonary conditions (10 mm Hg) 0.254 ± 0.01 (L/min), where the Medtronic M-OP showed the lowest leakage volume with 0.125 ± 0.014 (mL/min). CONCLUSION:: Hinge washing is related to transvalvar pressure difference in closed position. Valve brands differed significantly from each other in the amount of hinge washing

Quality of Life Among Patients With Congenital Heart Disease After Valve Replacement

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