Mitral valve replacement is a cardiac surgery procedure in which a patient’s mitral valve is replaced by a different valve. Mitral valve replacement is typically performed robotically or manually, when the valve becomes too tight (mitral valve stenosis) for blood to flow into the left ventricle, or too loose (mitral valve regurgitation) in which case blood can leak into the left atrium and back up into the lung. Some individuals have a combination of mitral valve stenosis and mitral valve regurgitation or simply one or the other.
A mitral valve replacement/repair is performed to treat severe cases of mitral valve prolapse, heart valve stenosis, or other valvular diseases. Since a mitral valve replacement is an open heart surgical procedure, it requires placing the patient on cardiopulmonary bypass to stop blood flow through the heart when it is opened up.
A mitral valve replacement is necessary when the valve doesn’t open or close completely. When the valve narrows or is stenotic the valve doesn’t let blood flow easily into the heart causing the blood to “back up” and pressure to build up in the lungs. This is dangerous because when the leaflets in the valve don’t meet correctly, blood may leak backwards into the lungs each time the heart pumps. If blood leaks backwards, the heart has to pump harder in order to push the same amount of blood forward. This is known as volume overload. The heart may compensate for this overload for many months or even years but eventually the heart begins to fail and patients show symptoms of shortness of breath or fatigue.
Details of the Procedure
A mitral valve replacement procedure is performed under general anesthesia, which will keep the patient asleep during the whole surgery. The preferred method is to first make an incision under the left breast rather than through the breastbone in the front of the chest, to get to the heart. After the heart is exposed, blood must be rerouted to a heart-lung machine (cardiopulmonary bypass). An incision is made in the left atrium to expose the mitral valve. The valve is then replaced with either a biological valve or mechanical valve. The heart is then closed with sutures. The patient is then taken off the cardiopulmonary bypass and blood is allowed to flow into the coronary arteries. If the heart does not beat on its own, an electric shock is used to start it. Then the chest is closed up.
There are several heart valve defects which stimulate the need for aortic valve replacement. However, the two most common reasons why patients need to replace their aortic valve are (i) blood flow is constricted across a narrowed heart valve (aortic stenosis) or (ii) blood flow is leaking back into heart (aortic regurgitation).
As a result of severe stenosis or regurgitation, the aortic valve must be replaced. Otherwise, future heart complications (enlarged heart muscle, congestive heart failure) can occur due to the strain on the cardiac muscle.
Aortic valve replacement surgery may also be needed if the heart valve leaflets have become damaged due to aortic valve calcification, a congenital bicuspid aortic valve, or other formsof aortic valve disease.
Atrial septal defect
Atrial septal defect (ASD) is a form of congenital heart defect that enables blood flow between the left and right atria via the interatrial septum. The interatrial septum is the tissue that divides the right and left atria. Without this septum, or if there is a defect in this septum, it is possible for blood to travel from the left side of the heart to the right side of the heart, or vice versa. Irrespective of interatrial communication bi-directions, this results in the mixing of arterial and venous blood. The mixing of arterial and venous blood may or may not be hemodynamically significant, if even clinically significant. This mixture of blood may or may not result in what is known as a “shunt”. The amount of shunting present, if any, dictates hemodynamic significance. A “right-to-left-shunt” typically poses the more dangerous scenario.
The right side of the heart contains venous blood with a low oxygen content, and the left side of the heart contains arterial blood with a high oxygen content. The construction of a heart void of an ASD prevents interatrial communication by means of an uncompromised interatrial septum. This prevents the atria from regular communication with each other, and thus oxygen-rich blood and oxygen-deficient blood do not mix together improperly.
What is a ventricular septal Defect (VSD)?
A ventricular septal defect is an opening in the ventricular septum, or dividing wall between the two lower chambers of the heart known as the right and left ventricles. VSD is a congenital (present at birth) heart defect. As the fetus is growing, something occurs to affect heart development during the first 8 weeks of pregnancy, resulting in a VSD.
Normally, oxygen-poor (blue) blood returns to the right atrium from the body, travels to the right ventricle, then is pumped into the lungs where it receives oxygen. Oxygen-rich (red) blood returns to the left atrium from the lungs, passes into the left ventricle, and then is pumped out to the body through the aorta.
A ventricular septal defect allows oxygen-rich (red) blood to pass from the left ventricle, through the opening in the septum, and then mix with oxygen-poor (blue) blood in the right ventricle.
The goal is to repair the septal opening before the lungs become diseased from too much blood flow and pressure. Repair is indicated for defects that are causing symptoms, such as poor weight gain and rapid breathing. Your child’s cardiologist will recommend when the repair should be performed based on echocardiogram and cardiac catheterization results.
The operation is performed under general anesthesia. Depending on the size of the heart defect and your physician’s recommendations, the ventricular septal defect will be closed with stitches or a special patch.
Tetralogy of Fallot (TOF) is a congenital heart defect which is classically understood to involve four anatomical abnormalities (although only three of them are always present). It is the most common cyanotic heart defect, representing 55-70%, and the most common cause of blue baby syndrome.
“Tetralogy” denotes a four-part thing in various fields, including literature, and the four parts the syndrome’s name implies are its four signs. This is not to be confused with the similarly named teratology, a field of medicine concerned with abnormal development and congenital malformations, which thereby includes tetralogy of Fallot as part of its subject matter.
As such, by definition, tetralogy of Fallot involves exactly four heart malformations which present together:
Arterial Switch Operation
Transposition of the great arteries (TGA) is a congenital heart defect in which the normal anatomic positions of the aorta and pulmonary artery are transposed (i.e., the aorta originates from the right ventricle and the pulmonary artery arises from the left ventricle). In babies with TGA, deoxygenated blood from the right ventricle exists the aorta and enters the systemic circulation; oxygenated blood from the left ventricle returns to the lungs via the pulmonary artery. The majority of babies born with TGA will not survive to their first birthday without a surgical correction.
Total anomalous pulmonary venous connection (TAPVC), also known as total anomalous pulmonary venous drainage(TAPVD) and total anomalous pulmonary venous return(TAPVR), is a rare cyanotic congenital heart defect (CHD) in which all four pulmonary veins are malpositioned and make anomalous connections to the systemic venous circulation.(Normally, pulmonary venous return carries oxygenated blood to the left atrium and to the rest of the body). A patent foramen ovale or an atrial septal defect must be present, or else the condition is fatal due to a lack of systemic blood flow.
Transposition of great Arteries
Transposition of the great vessels (TGV) is a group of congenital heart defects (CHDs) involving an abnormal spatial arrangement of any of the primary blood vessels: superior and/or inferior vena cavae (SVC, IVC), pulmonary artery, pulmonary veins, and aorta. CHDs involving only the primary arteries (pulmonary artery and aorta) belong to a sub-group called
transposition of the great arteries (TGA).