Patent ductus arteriosus

Dr Ammar Haouimi ◉ and Dr Yuranga Weerakkody ◉ et al.

Patent ductus arteriosus or arteriosum (PDA) is a congenital cardiac anomaly where there is persistent patency of the ductus arteriosus, a normal connection of the fetal circulation between the aorta and the pulmonary arterial system that develops from the 6^th aortic arch.

The ductus is a necessity in utero but usually undergoes functional closure 48 hours after birth. Patency of the ductus may be isolated or associated with other cardiac anomalies. In some circumstances, it is necessary to prolong life in patients with severe structural heart disease in whom a normal systemic circulation would be incompatible with life:

Non-cardiac associations

Radiographic features

Plain radiograph

Chest radiographic features may vary depending on whether it is isolated or associated with other cardiac anomalies and with the 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 edema may be evident.

Echocardiography

Transesophageal and transthoracic echocardiography have been used to identify these lesions, assess for the presence of complications, and plan surgical intervention. Suspicion is often aroused when a measured shunt fraction (Qp:Qs) is > 1.0, consistent with a left-to-right shunt.

With transthoracic echocardiography, the parasternal short axis view at the level of the aortic valve with color flow Doppler allows visualization of the flow through a patent ductus arteriosus. It classically appears as a high-velocity jet directed from the far-field toward the main pulmonary artery. Continuous wave Doppler interrogation reveals continuous flow throughout systole and diastole. Larger lesions, especially with concomitant pulmonary hypertension, may demonstrate lower flow velocities and/or alternating flow direction.

The suprasternal notch view may also depict aliased, continuous flow from the proximal descending aorta toward the right pulmonary artery, visible under the aortic arch in short-axis.

CT

MDCT can non-invasively provide detailed anatomical information ¹.

Krichenko classification based on CT angiography:

type A: conical ductus, prominent aortic ampulla with narrowing at pulmonary artery end
type B: window, short and wide ductus with blending of pulmonary artery
type C: long tubular ductus with no constrictions
type D: multiple constrictions with complex ductus
type E: elongated ductus with remote constriction

A ductus may have a tortuous morphology that does not fit in the Krichenko classification. This ductus type is usually observed in premature children and some authors proposed to classify it as type F or fetal type. Compared to types A to E, a type F ductus is larger, longer, tapers minimally from the aortic to pulmonary end, with a tortuous connection to the pulmonary artery giving a hockey-stick appearance ⁹.

Treatment and prognosis

medical
- prostaglandin E1: to keep ductus open
- indomethacin: to close the ductus
endovascular
- various closure devices
surgical
- clipping or ligation to close

Complications

Eisenmenger phenomenon

References

1. Morgan-Hughes GJ, Marshall AJ, Roobottom C. Morphologic assessment of patent ductus arteriosus in adults using retrospectively ECG-gated multidetector CT. AJR Am J Roentgenol. 2003;181 (3): 749-54. doi:10.2214/ajr.181.3.1810749 - Pubmed citation
2. Higgins CB, Disessa T, Kirkpatrick SE et-al. Assessment of patent ductus arteriosus in preterm infants by single lateral film aortography. Radiology. 1980;135 (3): 641-7. Radiology (abstract) - Pubmed citation
3. Edwards DK, Higgins CB, Merritt TA et-al. Radiographic and echocardiographic evaluation of newborns treated with indomethacin for patent ductus arteriosus. AJR Am J Roentgenol. 1978;131 (6): 1009-13. doi:10.2214/ajr.131.6.1009 - Pubmed citation
4. Goitein O, Fuhrman CR, Lacomis JM. Incidental finding on MDCT of patent ductus arteriosus: use of CT and MRI to assess clinical importance. AJR Am J Roentgenol. 2005;184 (6): 1924-31. doi:10.2214/ajr.184.6.01841924 - Pubmed citation
5. Wesenberg R, Wax R, Zachman R. Varying roentgenographic patterns of patent ductus arteriosus in the newborn. American Journal of Roentgenology. 1972;114 (2): . doi:10.2214/ajr.114.2.340
6. Merkle EM, Gilkeson RC. Remnants of fetal circulation: appearance on MDCT in adults. AJR Am J Roentgenol. 2005;185 (2): 541-9. doi:10.2214/ajr.185.2.01850541 - Pubmed citation
7. Schneider DJ, Moore JW. Patent ductus arteriosus. Circulation. 2006;114 (17): 1873-82. doi:10.1161/CIRCULATIONAHA.105.592063 - Pubmed citation
8. Wiyono SA, Witsenburg M, de Jaegere PP et-al. Patent ductus arteriosus in adults: Case report and review illustrating the spectrum of the disease. Neth Heart J. 2011;16 (7-8): 255-9. Free text at pubmed - Pubmed citation
9. Philip R, Waller BR, Agrawal V, Wright D, Arevalo A, Zurakowski D, Sathanandam S. Morphologic characterization of the patent ductus arteriosus in the premature infant and the choice of transcatheter occlusion device. Catheterization and cardiovascular interventions : official journal of the Society for Cardiac Angiography & Interventions. 87 (2): 310-7. doi:10.1002/ccd.26287 - Pubmed
10. Cao H, Chen Q, Zhang GC, Chen LW, Xu F, Zhang JX. Clinical study of stand-alone transthoracic echocardiography-guided percutaneous occlusion of patent ductus arteriosus. (2018) Anatolian journal of cardiology. 20 (1): 30-34. doi:10.14744/AnatolJCardiol.2018.90001 - Pubmed

Congenital heart disease

There is more than one way to present the variety of congenital heart diseases. Whichever way they are categorized, it is helpful to have a working understanding of normal and fetal circulation, as well as an understanding of the segmental approach to imaging in congenital heart disease.