Surgery of congenital heart disease assessed by radionuclide scintigraphy.

Intravenous injection of 99mTc-labeled macroaggregated albumin (MAA) followed by lung and whole-body scintigraphy results in data from which magnitude of right-to-left shunting and distribution of pulmonary arterial blood flow can be calculated. This information is useful in assessing the functional capacity of a surgical systemic-pulmonic anastomosis. Malfunctioning anastomoses do not significantly reduce right-to-left shunting and may cause unilateral pulmonary hyperperfusion. However, preferential nuclide accumulation may occur in either lung, regardless of shunt function. Consequently, the degree of right-to-left shunting must be determined to fully assess a surgical anastomosis. This technique also allows for assessment of the reduction of right-to-left shunting after intracardiac repairs of congenital cardiac abnormalities.