A mix of oxygenated and de-oxygenated blood is sent to the body through the anastomosed aorta and pulmonary trunk. At 18 to 24 months of age, if the patient does well after the Glenn shunt and pulmonary resistance remains low, the third stage of reconstruction is possible. With the Fontan operation, the venous blood from the lower part of the body is also diverted to the lungs, thus creating the 'complete' Fontan circulation. However, if the child is not well or the pulmonary resistance is considered too high, then no further surgical treatment is possible. De-oxygenated blood from the superior vena cava and inferior vena cava is routed directly to the lungs.
Oxygenated blood is sent to the body through the anastomosed aorta and pulmonary trunk.
Transplantation Heart transplantation is carried out using the same basic techniques as for other transplants. In the case of pediatric heart transplants, the greatest problem is that infant donor hearts are in short supply. Thus transplantation is a treatment for only a limited number of babies with hypoplastic left heart syndrome. In addition, recipients can survive only with the assistance of heavy doses of expensive medication to prevent rejection of the transplanted tissue. These drugs also have significant side-effects, such as the risk of infection and lymphatic cancer, and must be taken by recipients for the rest of their lives.