What are the problems with a Norwood staged operation ?

Each of the three stages has its own risks and complications.

Norwood operation - Stage 1

The first stage is the most critical. The operation is only palliative - that is, it does not correct the defect entirely, but only provides partial relief. At the end of the operation, the heart is provided with a single pumping chamber - the right ventricle - which must provide the entire body and the lungs with blood flow.
The average patient spends a week or 10 days in the intensive care unit, and around 20 days in hospital. Numbers do not mean much in a condition like HLHS where most hospitals have not operated on many children, but around 40% do not survive the first stage. In centers which are more experienced with such operations, the results are better. And they are improving every day, and soon will hopefully be good enough to allow more confident and encouraging projections of outcome.
After a first stage Norwood operation, the follow up care of children is similar to that of a patient being considered for a Fontan operation. The important issues are to

• preserve ventricular function
• ensure good and symmetric growth of pulmonary arteries
• keep lung blood vessel resistance low
• prevent any obstruction to blood flow at the inter-atrial septum.

Most centers follow a fixed protocol of doing a cardiac catheterization test after six months. At this time, the future course of treatment is decided upon.
In the meantime, if there are any added complications, the protocol may be modified. Problems that may occur include an increase in severity of cyanosis - bluish discoloration - or a failure of the child to feed well or grow and develop normally. Heart failure may set in too. In all of these conditions, an earlier catheterization study may be required.

Norwood operation - Stage 2

The second stage of the Norwood operation is usually performed at 6 to 9 months of age. It is a much safer operation than the first stage. Post operative care is routine, and follow up is the same as for patients who have had a Bidirectional Glenn shunt for other single ventricle conditions.
One complication that may arise is an increase in severity of cyanosis due to the development of abnormal vein connections - called veno-venous collaterals. This can be treated by a method called TRANS-CATHETER EMBOLIZATION. In this method, small pellets of teflon or metal wire are delivered into the abnormal veins through a catheter. These cause blood to clot inside the abnormal collateral veins, and block them.
At around 9 to 12 months after the second stage, a cardiac catheterization test is repeated. If the situation is suitable for a Fontan type operation, the third stage is carried out. This is often possible at an age of 18 to 24 months. The evaluation and technique of the Fontan operation are the same as for Tricuspid Atresia, which I have discussed in another section.

Norwood operation - Stage 3

This is in effect a complete Fontan operation. Risks, complications, and long term outcome are likely to be similar to Fontan operations performed for other diseases. Research is currently in progress to find out what factors are peculiar to HLHS in determining outcome.

What is heart transplantation ?

 

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