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.