Innovative Modeling of Outcome in Cardiac Surgery

In the normal heart both left and right ventricle have a valve at the atrio-ventricular connection and at the ventriculo-arterial connection. In the left ventricle the inflow valve is the mitral valve and the outflow valve is the aortic valve. In the right ventricle the inflow valve is the tricuspid valve and the outflow valve is the pulmonary valve. These heart valves ascertain that blood only flows in one direction through the heart. The valves are made of strong, thin flaps of tissue, called leaflets. The valves control the blood flow through the heart by opening and closing the leaflets during the contractions of the heart. Heart valve disease occurs when one or more of the heart valves do not work correctly because of valvular stenosis or valvular regurgitation, or a combination of the two. Valvular stenosis occurs when a heart valve doesn’t fully open due to stiff or fused leaflets or when a valve is congenitally too small. This limits the amount of blood that can flow through the valve. Valvular regurgitation, also known as valvular insufficiency, occurs when a valve does not close properly. This will lead to blood leaking back through the valve when it should be closed. All four heart valves can develop stenosis, regurgitation of a combination of both stenosis and regurgitation. In case heart valve disease is not treated, it can have negative impact on a person’s quality of life and may even become life-threatening. During the past decades, great advances in the surgical treatment of heart valves disease have been achieved. This thesis will focus on the surgical treatment of aortic and pulmonary valve disease.