Patient Selection For Fontan Operation

What are the criteria for selecting a patient for Fontan operation ?

Ten characteristics were identified which would permit a good outcome after the Fontan operation. Whimsically, these were called the TEN COMMANDMENTS of the Fontan procedure.

The ten commandments included data which could be obtained before surgery by examining the patient, and carrying out tests like echocardiography and cardiac catheterization. When more of the ten commandments are "obeyed", the better are the chances of a happy result from surgery.

What are the ten criteria ?

Here is a list of the ten criteria:

1. Age above 4 years
2. No distortion of lung arteries from prior shunt surgery
3. Normal venous drainage
4. Normal ventricular function
5. Adequate pulmonary artery size
6. No atrio-ventricular valve leak
7. Low pulmonary artery pressure (below 15 mmHg)
8. Low lung blood vessel resistance
9. Normal heart rhythm
10. Normal right atrial size

What do these criteria mean ?

In effect, all these criteria were to ensure that the resistance of blood vessels in the lung was not too high. A high resistance would interfere with passive lung blood flow. This could be produced by very small pulmonary arteries, blood vessel wall thickening and hardening, mitral valve leak or reduced function of the left ventricle. In all of these conditions, a Fontan operation would not be performed, or modified to reduce the risks.

What are the kinds of Fontan-type operations ?

Ever since its first description, the Fontan operation has been modified many times. Each modification aimed to avoid one of the drawbacks of the previous types. While some are definitely better, others are not very different. We are still striving to devise the "best" type of Fontan repair for each group or individual.

As I mentioned earlier, in the original Fontan operation, the venous blood was diverted to the lungs directly from the right atrium, and the ASD was closed. While Dr.Fontan used an artificial valve between the inferior vena cava (IVC) and the right atrium, future modifications eliminated this.

The aims of the "ideal" Fontan operation are

• To achieve a smooth stream-lined blood flow from veins to the lungs
• To retain growth potential as the child becomes older
• To avoid use of artificial materials
• To be adaptable to patients of any age group

To learn about the most frequently performed TCPC Fontan (Total Cavo-Pulmonary Connection), read the next article on this site.