Discussion
Although being mostly asymptomatic, aneurysm of the ductus arteriosus (DAA) can lead to severe complications in some cases. It is reported in less than 1% of neonatal autopsies, whereas Jan et al. reported relatively high incidence rate of 8.8% without any symptomatic case, probably because of the diagnostic criteria they used [1,2]. DAA related symptoms as thromboembolism, spontaneous rupture, compression of airways and nerves and even death are reported in up to 16-30% of patients [3-6].
Etiology of DAA is unknown, however hypothesis as abnormal elastin expression or structure, ductal wall weakening and reduced intimal cushions are reported in some studies. Associated connective tissue diseases (Marfan syndrome, Ehler Danlos syndrome etc.) with DAA supports the hypothesis of ductal wall abnormality [2,3].
Most cases are asymptomatic and regress spontaneously and should be managed with clinical follow up. Jan et al. reported that all of the cases regressed spontaneously in the neonatal period and suggested no intervention [2]. However, in case of complications such as extending thrombosis, laryngeal nerve or airway obstruction and rupture of aneurysm, surgical intervention should be considered. Spontaneous regression occurs in steps as constriction, thickening, trombus formation and closure. Although thrombosis is a step in natural history during spontaneous closure, large aneurysm and extension of the thrombus into the descending aorta indicated surgical excision of the aneurysm in our case. In some cases, especially in patients with nerve palsy, ligation and decompression of the aneurysm instead of excision is also suggested.
In our patient thrombosis developed in third day of life during expectation of spontaneous closure. Clinical follow up for the possible symptoms and serial echocardiography should be enrolled to identify the need for intervention in patients with DAA.