Single Ventricle Defect and it’s Palliation
The normal heart has two pumping chambers, on either side. The right ventricle pumps blood to the lungs via the large oxygen poor blue blood carrying tube called the pulmonary artery. The left ventricle on the other hand, pumps oxygen rich blood normally to the whole body, via the large blood carrying tube called the aorta. Unfortunately in some complex malformations, babies are born with only one ventricle. This is one of the most complex of heart defects. Complete fix/ cure is not yet available for these types of heart defects. What can be done is a series of operations in different stages, such that after the final stage, the blue, oxygen poor blood goes to the lungs and the red, oxygen rich blood goes to the whole body. The final correction is done such that oxygen poor blue blood reaches the lungs without the help of a pumping chamber. As there is no force pushing blood to lungs like normal - no right ventricle - low lung pressure is an absolute necessity for this correction to work. The only available pumping chamber then pumps only red, oxygen rich blood to the whole body through the aorta. As the blood pressure in the aorta is high, a pumping chamber is a necessity to get blood moving into the aorta and to the whole body. Once these staged surgeries are done, the child is expected to live for 30-40 years at best, with regular medical attention. Most children will need two stages of surgeries to achieve this. Some others will need three instead of two stages.
Whether a baby needs two surgeries or three surgeries depends entirely on the type of abnormality in the heart. Most importantly, it depends on how much blood is reaching the lungs. If there is overflow of blood to the lungs, the lung pressure is high and the baby is in heart failure. This needs to be controlled by a stage 1 procedure called PA Banding. If enough blood is not reaching the lungs and the baby is blue before the time that stage 2 can be safely performed, this needs to be corrected by another stage one procedure called BT Shunt.
Stage 2 Single Ventricle Palliation - Bidirectional Glenn Shunt and Stage 3 Single Ventricle Palliation - Fontan Completion are the other surgeries done to correct the single ventricle defect.