Selection of patients with truncus arteriosus for surgical correction; anatomic and hemodynamic considerations.

Six years have passed since the first successful surgical correction of truncus arteriosus. A review of our experience enables some conclusions regarding the operation. Patients with mild or moderate truncal valve incompetence do not need truncal valve replacement. Patients with severe truncal valve incompetence require valve replacement, which is associated with a significantly increased surgical mortality. The surgical mortality is not increased in hemodynamically favorable patients who have only one pulmonary artery. However, these patients are especially likely to have early development of severe pulmonary vascular disease. The surgical mortality for the patient with uncomplicated disease and two pulmonary arteries, with pulmonary resistance of less than 8.0 units m2, is 10%. In patients with pulmonary resistance between 8.0 and 12 units i2, the mortality is approximately three times greater. Patients with pulmonary resistances greater than 12.0 units m2 are probably inoperable. Different hemodynamic criteria must be applied in assessing the operability of patients with a single pulmonary artery. A systemic arterial oxygen saturation less than 85% in a patient with two pulmonary arteries and without pulmonary artery stenosis or a pulmonary artery band usually indicates inoperability. Elective operation usually is deferred until a patient is four years old, but if the patient's clinical condition warrants, the procedure can be done at any time after the age of one year, with a good chance of success. Follow-up on most operated patients has been encouraging.