In this section
This defect is a form of Tetralogy of Fallot in which there is
complete obstruction of the Pulmonary Artery resulting in total
diversion of blood from the right ventricle into the aorta.
Survival depends on the presence of a number of naturally occurring
connecting blood vessels between the Aorta and the Pulmonary
Arteries in the lungs, which are called 'Collaterals' - or
sometimes 'MAPCAs' (Major Aorto-Pulmonary Collateral
The 'Collaterals' are usually several in number and carry blood
to different parts of the lung circulation. Surgery is often a
matter of connecting up the multiple Collaterals at different
operations before performing a Complete Repair in suitable cases.
The final 'Repair' usually involves insertion of a graft valve
('Conduit') to replace the absent Pulmonary Valve.