Case of the Month Dr Natasha Larocque PGY

Case of the Month Dr. Natasha Larocque PGY 2, Diagnostic Radiology Mc. Master University

Case Presentation • 70 year old female presents to the ED with increased SOB, pleuritic chest pain and an elevated D-dimer • Patient has a known history of left upper lobe hemorrhage that was embolized in 2003 – No previous imaging available

Findings • No evidence of pulmonary embolism • There is aplasia of the left main pulmonary artery

Findings • No evidence of pulmonary embolism • There is aplasia of the left main pulmonary artery

Findings • No evidence of pulmonary embolism • There is aplasia of the left main pulmonary artery

Findings • Aplasia of the left main pulmonary artery results in decreased left lung volume

Unilateral Pulmonary Artery Atresia Incidence and Embryology • Prevalence ~ 1/200 000 – Male=female – Right > left • Due to a malformation of the 6 th aortic arch Image courtesy of Medicowesome http: //medicowesome. tumblr. com/post/67973293114/aortic-arch-derivatives-mnemonic-images- hd

Unilateral Pulmonary Artery Atresia Clinical Presentation • Variable – Asymptomatic – Chest pain/SOB – Recurrent chest infections – Pulmonary hypertension – Hemoptysis – Pleural effusion – High altitude pulmonary edema

Unilateral Pulmonary Artery Atresia Associations • Other cardiac anomalies (60%) – ASD, VSD, coarctation, right-sided aortic arch, tetralogy of Fallot, truncus arteriosus • Occur in isolation (40%)

Unilateral Pulmonary Artery Atresia X-ray Findings • Absent PA shadow on the affected side • Findings related to volume loss of the affected hemithorax – Cardiomediastinal displacement – Ipsilateral elevated hemidiaphragm – Contralateral compensatory hyperinflation of the hemithorax CXR for the same patient

Unilateral Pulmonary Artery Atresia CT Pulmonary Angiogram • Mainstay for diagnosis – Abrupt termination of a pulmonary artery • Parenchymal findings include – Bronchiectasis – Mosaic attenuation of both lungs due to altered perfusion

Unilateral Pulmonary Artery Atresia Complications • Hemoptysis • Bronchiectasis • Pulmonary hypertension – Greatest morbidity

Unilateral Pulmonary Artery Atresia Treatment • Surgical – Pneumonectomy and surgical revascularization for recurrent hemoptysis/infections • IR – Selective embolization of bronchial/systemic collaterals for patients with massive hemoptysis • Pharmacological – For concomitant pulmonary hypertension

References 1. Steiropoulous, P. , Archontogeorgis, K. , Tzouvelekis, A. , Ntolios, P. , Chatzistefanou, A. & Bouros, D. (2013). Unilateral pulmonary artery agenesis: A Case Series. Hippokratia, 17(1): 73 -76. 2. Lelegianni, M. & Weerakkody, Y. (2017). Unilateral pulmonary artery atresia. Radiopedia, available from: https: //radiopaedia. org/articles/unilateralpulmonary-artery-atresia