Breathing With Half a Pulmonary Circuit: Three Cases of Unilateral Pulmonary Artery Agenesis.

Unilateral pulmonary artery atresia (UPAA) is a rare congenital anomaly marked by the absence of one of the pulmonary arteries. This article examines three instances of UPAA, predominantly affecting the right side, although one case involved the left side. Common characteristics included hemoptysis, observed in two patients-one with a chronic history necessitating embolization and another with a mild, recent onset. The third case was identified incidentally during a preoperative evaluation. All cases demonstrated varying degrees of ipsilateral lung volume reduction and associated interstitial changes or fibrosis. UPAA can be asymptomatic or present with hemoptysis, recurrent infections, or breathlessness. Diagnosis relies on computed tomography pulmonary angiography (CTPA) or magnetic resonance (MR) angiography. Management ranges from observation to embolization or pneumonectomy in severe cases. Mortality is around 7%, with pulmonary hypertension and haemorrhage being major prognostic factors.