Pulmonary Atresia

Pulmonary atresia is one of congenital cardiovascular anomaly in which there is complete disruption between the right ventricular outflow tract (RVOT) and the main pulmonary artery.

 Epidemiology

The estimated incidence is 1 in 10,000 births.

Pathology

The term pulmonary atresia can cover a broad spectrum of abnormalities depending on the extent of the disruption.

Sub types

It can be classified into 3 sub-types 1:

pulmonary atresia with intact inter ventricular septum (PA-IVS)

pulmonary atresia with VSD (PA-VSD)

complex pulmonary atresia (pulmonary atresia with complex cardiac malformation)

Associations

tetralogy of Fallot: PA-VSD is considered by some authors as a severe from of tetralogy of Fallot

Radiographic features

CXR

PA-VSD 3:

normal or mildly enlarged heart with poor / diminished pulmonary arterial vascular markings

asymmetrical vascular suggest stenosis within pulmonary arterial tree

there can be plethora due to horizontal arteries forming aorto-pulmonary collaterals

mottled appearance as the lung periphery may suggest pleuro-pulmonary collateral formation

Cardiac MRI

Allows direct visualization of anomaly. Cine sequences may show a dilated non contracting right ventricle 6.  MR angiography allows detection of aortopulmonary collaterals and patent ductus arteriosus (if present).

Treatment 

Management varies depending on the presence of a VSD. Prostaglandin E1 is used to keep the ductus open 5.