Dr. Natasha Larocque PGY2, Diagnostic Radiology McMaster University Case of the Month Dr. Natasha Larocque PGY2, Diagnostic Radiology McMaster 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 6th 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 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. Lelegianni, M. & Weerakkody, Y. (2017). Unilateral pulmonary artery atresia. Radiopedia, available from: https://radiopaedia.org/articles/unilateral-pulmonary-artery-atresia