The ducus arteriosus is a necessary fetal circulatory pathway allowing the carriage of oxygenated blood from the pulmonary artery to the aorta. Shortly after birth this closes, probably as a result of the drop in resistance in the pulmonary circulation, and the mechanism is thought to be due to prostaglandin inhibition. Continuing patency of the ductus arteriosus accounts for 5% of congenital heart disease.
Aneurysm formation in the PDA has been reported before in both adults and children. It is a rare but potentially fatal condition. The pathogenesis appears unclear. It is most commonly associated with missed childhood PDA. However, it has been reported in vasculitic processes ie. Kawasaki's disease, connective tissue disorders such as Marfan's syndrome or following recanalisation of the PDA after aneurysmal dilatation in aortic co-arctation.
Symptoms are often discrete, but the most usual presentation is dyspnoea due to heart failure. Left recurrent nerve palsy as a result of cardiovascular pathology is termed Ortner's syndrome. Laryngeal palsy as a presenting feature of PDA aneurysm is extremely rare. In rupture this condition is commonly fatal.
Investigation involves chest radiography and CT scanning, colour doppler echocardiography and aortography.
While there is controversy surrounding whether all silent PDAs require closure, most authors agree that the treatment of the symptomatic aneurysmal ductus arteriosus is mandatory, due to the risk of rupture and endarteritis.
Treatment is often operative ligation of the patent ductus arteriosus, usually performed in a specialist cardiothoracic centre through a left thoracotomy, the risks including left recurrent laryngeal nerve damage and extensive haemorrhage.
A move towards endovascular closure in the radiology department has been reported as far less invasive and associated with considerably shortened hospital stay. The approach includes access via common femoral artery puncture and cannulation of the PDA with deployment of a suitably sized Raskind occlusive device or coils. The risks include cerebrovascular accident, mal-deployment, and failure to occlude.