Pulmonary valve stenosis
In this heart defect, the pulmonary artery valve (pulmonary artery valve) is malformed and narrowed to varying degrees. The right ventricle must therefore exert high pressure in order to pump the blood through this constriction into the pulmonary artery (pulmonary artery). This constant ‘training’ of the heart muscles leads to a thickening of muscle bundles, which in turn can cause additional constriction.
Diagnosis
Diseases of the pulmonary valve can be detected by auscultation (listening to the heart with a stethoscope) and a sharp heart murmur with a cardiac ultrasound examination (echocardiography). If necessary, our doctors will carry out an electrocardiogram (ECG) or a chest X-ray.
Additional diagnostic tools are also available at the DHZC:
Therapy
According to current studies, this heart defect can almost always be successfully treated in the long term with balloon catheterisation. A cardiac catheter is advanced from the groin via the right ventricle and the right ventricular outflow tract into the pulmonary artery. The valve is then ‘blown up’ with the help of a balloon. There is usually a slight leakage of the valve to varying degrees, but this is well tolerated. No further treatment is required if there is only a small amount of residual leakage. If there is an additional narrowing below the valve, or if a significant residual narrowing remains, it may be necessary to correct it by means of an operation using a heart-lung machine.
In rare cases, children are born without a pulmonary valve at all, which is known as pulmonary atresia. If only the valve is closed, this can also be treated with cardiac catheterisation. However, if there is a prolonged obstruction, heart surgery with the use of a heart-lung machine is required.
After connecting the heart-lung machine, the trunk of the pulmonary artery is opened and the malformed valve is inspected. Often the valve does not have three valve pockets - as is usually the case - but only two or even just one. Ideally, the commissures (boundaries between the valve pockets) can be opened with a scalpel to ensure better opening of the valve.
Often, however, the valve is so severely malformed that there is no real formation of valve pockets, but only a thick plate of tissue with a small opening. In this case, the flap must be removed. If the valve ring is too small compared to the normal value, the valve ring must be opened. Thickened muscle bundles in the right ventricular outflow tract are severed. The entire right ventricular outflow tract is then widened with the help of a patch taken from the pericardium (tetralogy of Fallot).
The patch thus widens the outflow tract of the right ventricle, the pulmonary artery valve and the pulmonary artery trunk. The aim of achieving an unobstructed outflow from the right ventricle into the pulmonary artery is thus guaranteed. Depending on the leakiness of the valve, attention must be paid to an enlargement of the ventricle in the long term due to the varying degrees of backflow from the pulmonary artery back into the ventricle. If the increasing size of the right ventricle exceeds a certain value, a valve in the form of a homograft (human donor valve) or allograft (bovine or porcine valve) must be used.
Recommendation for further treatment
We recommend continuing antibiotic prophylaxis for the known indications.
Forecast
Long-term course
The child's prognosis for the underlying heart defect is generally very good in the short and medium term, even without surgery. There is usually no significant gradient detectable across the right ventricular outflow tract. ‘Gradient’ describes the difference in blood pressure before and after the constriction or between the chambers. A high gradient indicates a significant constriction or a considerable pressure difference that impedes blood flow.
A certain gradient across the outflow tract can be advantageous, especially in the long term, with regard to maintaining RV function compared to free leakage of the pulmonary valve. In the further course, a higher degree of stenosis or insufficiency in the area of the pulmonary valve may necessitate re-intervention.
