Pulmonary Atresia with VSD and MAPCAs

  • 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 Arteries).


    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.