How is this condition different from Pulmonary atresia with VSD ?
This condition involves a basic problem with the tricuspid valve not being normal. If the inflow to the right pump is not good, it will not grow and consequentially, the Pulmonary valve will not be normal.
What are the defects in this condition ?
The true defect here is the Pulmonary valve being covered with a membrane. This does not allow the blood to get to the lungs.
How is it decided what treatment will be offered ?
The decision is based on whether the tricuspid valve size is normal and if not, how much smaller is it from the normal. If the valve is near normal, the child’s right ventricle will carry a potential to be normal. If that is the case, the membrane needs to be perforated and communication between the heart and the lug tubes needs to be established. This, on many occasions, is done without surgery; by intervention.
What if the RV has the potential to grow but currently is small ?
If that is the case, the lung blood flow may need support from the PDA and PDA may need to be kept open for some time till the RV can accommodate enough blood. This may take till few days after the intervention to several weeks for the RV to return to normal.
How does the blood flow when the RV is smallish?
The RV does not allow all of the blood to come in, and in that situation, the blood crosses the normal hole between the upper chambers (PFO) and mixes with the red blood. So, the baby tends to be blue for some time till the RV allows all the blood to come into it; and there by push most of it into the left upper chamber.
What are the rare situations where one would not operate on the child in this condition?
In the rarest of situation, the RV can be very small and the pressure in the RV be so high that the blood channels open up into normal ares like the coronary arteries. In that case, the coronary circulation can become dependent on the RV and if that happens the Pulmonary valve cannot be opened up. The surgeries get to be very high risk in these situations.
What is a one and a half repair ?
If the right ventricle seems to be small, it may never accommodate the full blood returning into the right heart. In that case, the blood will go into the left upper chamber via the PFO and keep the baby blue. One way to overcome this problem is to take the blood return from upper half of the body out of the heart and put it into the lugs directly. This mounts to 1 and a 1/2 repair (referring to the 1 full left ventricle but only 1/2 of the right ventricle). This is system between the normal bi-ventricular repair and the single ventricles!
What all can be repaired in the cath lab without surgery ?
The perforation of the pulmonary valve can be made in the cath lab. Later on, when the PFO needs to be closed, this can be tested for and done in the cath lab. In addition, balloon dilatation of the pulmonary valve can also be done in the cath lab. If the PDA needs to be kept open in the acute phase, this can be done by stenting the PDA. If the stented PDA needs to be closed, that can also be done by the implantation of the vascular plug.