Aortic valve replacement surgery
Aortic valve replacement surgery is an "open heart" procedure performed by cardithoracic surgeons for treatment of narrowing (stenosis) or leakage (regurgitation) of the aortic valve. Replacement of the aortic valve requires open-heart surgery, in which the breast bone (sternum) is split down the middle, allowing access to the heart. The heart is stopped
during critical parts of the operation and a special machine pumps oxygenated blood throughout the body. The diseased valve is removed and a new valve is sewn in.
There are several types of valve replacement operations and the choice of which operation is best for a child is decided through discussions with the parents, the pediatric cardiologist, and the pediatric cardiac surgeon.
Valve replacements alone are not always enough to relieve the narrowing out the ventricle. Sometimes the whole area leading out of the ventricle to the aorta is too small. The supporting structure of the valve, called the valve annulus, may be too narrow even if the leaflets are opened up as far as possible. In these cases the valve replacement is performed with a procedure called a Konno procedure. This involves enlarging the left ventricular outflow tract and the valve ring. It is done through an incision into the outflow tract of the right ventricle and the septum or wall between the right and left ventricles. A patch is placed in this area that enlarges it. The Konno procedure can be done with any type of aortic valve replacement.
Ross procedure: This is one type of valve replacement operation. The surgeon makes an incision down the center of the breastbone. The heart is stopped for a brief period of time while a heart lung bypass machine supports the body.
The coronary arteries are removed from the aortic valve and the diseased aortic valve is removed. The person's own pulmonary valve is then removed from its position in the right ventricular outflow tract and sewn into place as the new aortic valve. The coronary arteries are then reattached to the new valve. A tissue valve, called a homograft or an allograft, is then sewn in the place where the person's own pulmonary valve was removed. This valve is from a human donor and is not live tissue so it will not be rejected by the person's own immune system. It is expected that the tissue valves will need to be replaced in five to ten years but since this is a fairly new procedure the actual frequency of valve replacements is not yet known.
Mechanical valve replacement: When the surgeon performs this operation an incision is made down the center of the breastbone and the heart is stopped for a brief period of time while the body is supported by the heart-lung bypass machine. The coronary arteries are removed from the diseased aortic valve and the valve is removed. A prosthetic valve is then inserted into the aortic valve ring (annulus) and the coronary arteries are reimplanted. The mechanical valve works like a human valve, opening to let blood out of the heart and closing to keep blood from the body from getting back into the heart. It makes a clicking noise when closing that may be heard when the room is quiet or when listening near the chest.
In order to prevent clots from forming on the valve, people with mechanical valves must take a blood thinner called warfarin (Coumadin) for the rest of their lives. Blood tests are done, usually once a month; to make sure that the blood is thinned enough to prevent clots but not so much that the person is at risk for bleeding.
Mechanical valves usually last a long time, potentially for life, without needing to be replaced. A disadvantage is that the person must always take blood thinners. The use of Coumadin during pregnancy is associated with birth defects and early fetal demise, so this may not be the operation of choice for women of childbearing age.
After successful aortic valve replacement, patients can expect to return to their preoperative condition or better. Anticoagulation ("blood thinners") with a drug like Coumadin may be prescribed for 6 weeks to 3 months after surgery for those with biological valves, and for life for those with mechanical valves. Once the wounds have healed, most patients should experience few if any restrictions to activity. A patient will require preventative or prophylactic antibiotics whenever having dental work, and should always tell a doctor about their valve surgery before any surgical procedure.