Patent ductus arteriosus

A patent ductus arteriosus (PDA) is a congenital cardiac anomaly with persistent patency of the ductus arteriosus (6th aortic arch).

A ductus is a necessity in in utero but usually undergoes functional closure by around 48 hours following birth. It may remain patent in some circumstances. PDA prevalance can be up to 12% of congenital cardiac anomalies 4.

Commonly occurs as an isolated phenomenon but can also occur in combination with other cardiac anomalies.

A persistant PDA can be beneficial through compensatory effects when present with certain other anomalies such as

* tetralogy of Fallot
* Eisenmenger syndrome
* hypoplastic left heart or
* pulmonary atresia.

Clinical features

A large PDA classically gives a loud continuous machinary like murmur

Non cardiac associations

* prematurity
* surfactant deficiency
* trisomy 18
* trisomy 21
* rubella

Radiographic features

Plain film

X ray features may vary depending on whether it is isolated or associated with other cardiac anomalies and with direction of shunt flow (right to left or left to right). Can have cardiomegaly (predominantly left atrial and left ventricular enlargement if not complicated). Obscuration of the aortopulmonary window and features of pulmonary oedema may be evident.

CT

MDCT can non invasively provide detailed anatomical information1.

Echocardiography / Ultrasound

Direct visualisation of PDA. Colour doppler can provide information of direction of flow.

Complications

  • Eisenmenger phenomenon

Management

* medical
o prostaglandin E1 > to keep ductus open
o indomethacin > to close ductus
* endovascular
o various closure devices
* surgical
o clipping or ligation to close.

pda.jpg

Anterior view of the heart demonstrating a patent ductus arteriosus with relationship to left vagus nerve and recurrent laryngeal nerve. Original file from Wikimedia

Article Author : Dr Yuranga Weerakkody, Radiopaedia

References

* 1.Gareth J. Morgan-Hughes et.al, Morphologic Assessment of Patent Ductus Arteriosus in Adults Using Retrospectively ECG-Gated Multidetector CT, AJR 2003; 181:749-754
* 2. C B Higgins et.al, Assessment of patent ductus arteriosus in preterm infants by single lateral film aortography. Radiology, 135, 641-647, Jun 1980
* 3. DK Edwards et.al, Radiographic and echocardiographic evaluation of newborns treated with indomethacin for patent ductus arteriosus, American Journal of Roentgenology, Vol 131, Issue 6, 1009-1013
* 4. Goitein O, Fuhrman C R, Lacomis J M, Incidental Finding on MDCT of Patent Ductus Arteriosus: Use of CT and MRI to Assess Clinical Importance, Pictorial essay, AJR 2005;184:1924–1931
* 5.Wesenburg et.al, Varying Roentgenographic patterns of patent ductus arteriosus in the newborn, AJR, VoL. 114, No, 2
* 6.Elmar M. Merkle et.al, Pictorial Essay, Remnants of Fetal Circulation: Appearance on MDCT in Adults, AJR 2005; 185:541-549

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