Unilateral absent pulmonary artery (UAPA) with patent ductus arteriosus (PDA) in a young woman with repeated respiratory infection: A case report.

Unilateral absent pulmonary artery (UAPA) first introduced in literatures by Oscar Fraentzel in 1898 is a rare vascular anomaly where the main pulmonary artery, rather than bifurcating, gives a solitary pulmonary artery branch to one of the lungs. The other lung, on the affected side, gets blood supply through collateral circulations, frequently through enlarged bronchial arteries. It is seen in 1 in 200,000 live births. It occurs due to the involution of the proximal sixth aortic arch on one side resulting in a unilateral absent pulmonary artery. The diagnosis can be made using contrast-enhanced CT and MRI images. Cases of UAPA can be seen in infants presenting with congestive cardiac failure and pulmonary arterial hypertension (PAH). Undiagnosed cases can result in repeated respiratory infections, complicating with bronchiectasis, pulmonary hypertension, and fibrosis gradually reducing the patient's quality of life. In adults, the diagnosis is sometimes made with cross-sectional studies when investigating causes of repeated respiratory infection or hemoptysis. We report a case of right-side UAPA with patent ductus arteriosus (PDA) and early signs of PAH in a 24-year-old female patient with a previous history of repeated respiratory infection uncovered during contrast-enhanced chest CT imaging.