After recovery from stage 1 palliation, acute care is transitioned to chronic therapies that allow preservation of organ function and somatic growth. As such, interstage management should include pharmacologic therapy, vigilant surveillance, adequate nutrition and somatic growth.

Pharmacologic therapy will vary from one patient to the other but may include vasodilators, diuretics, digoxin and anticoagulation (like aspirin or subcutaneous low-molecular-weight heparin). The saturation awake or asleep should be over 78% and to achieve these values, oxygen may be given via nasal cannula. Any of these prescribed therapies will require frequent outpatient adjustments. Weight will be monitored frequently, and some families are provided with a home scale. Adequate nutritional support is often achieved with gavages and even gastrostomy with tube placement. Some infants are so sick, that they have to stay in hospital between the two first stages of their palliation. This period between the first stages of palliation is the most critical one where most mortality occurs.

After the stage 2 operation (around 4-6 months of age), patients experienced improved activity and physiologic reserve. However, increasing cyanosis following stage 2 palliation is predictable.

Fontan procedure or the stage 3 palliation is usually the last anticipated operation. In general, the operation is performed between 18 months and 4 years of age. After this operation the saturation will achieve a normal range and significant clinical improvement will be noticed, with increased exercise tolerance. Those children can expect an almost normal life. Some complications can happen with time and follow-up is mandatory with clinical visits every 6 months or every year. Complications include ventricular dysfunction, hypoxemia, protein losing enteropathy, thromboembolism, arrhythmias and liver disease. Majority of patients will have to take a chronic medication and many of them will eventually need a pacemaker. Advances in medical and surgical treatment are made regularly and the life expectancy of those patients is increasing every year. As the first Fontan operations were done about 40 years ago, it is hard to for see what will happen 80 years down the road. As for everybody, an healthy diet, avoiding obesity and an active life (exercises with the legs may be beneficial in Fontan patients) are recommended for every patient who has undergone a Fontan palliation.