Unilateral pulmonary artery atresia (UPAA), also known as unilateral absence of the pulmonary artery (UAPA) or proximal interruption of the pulmonary artery, is a variant of pulmonary artery atresia.
The term interruption is preferred by some to absence or atresia because the anomaly pertains only to the proximal pulmonary artery while the distal pulmonary arterial tree is maintained 13.
The estimated prevalence is around 1 in 200,000 young adults. The reported frequency on the right side is slightly greater for some reason 10.
Can be variable and include:
- asymptomatic: adult patients with UPAA are often asymptomatic 8
- chest pain
- pleural effusion
- recurrent chest infections: lack of arterial blood flow to the affected lung may result in poor delivery of inflammatory cells to sites of inflammation and impaired ciliary function
- reduced exercise tolerance
- pulmonary hypertension
- high-altitude pulmonary edema
It commonly occurs on the side opposite to that of the aortic arch.
The distal branches of the affected artery usually remain intact and can be supplied by collateral vessels from other arteries such as bronchial, intercostal, internal thoracic, subdiaphragmatic, subclavian, or even coronary arteries.
It occurs in association with other cardiac anomalies in ~60% of cases:
- septal defects
- coarctation of aorta
- right aortic arch
- truncus arteriosus
- tetralogy of Fallot
In around 40% of cases they occur in isolation, where it is then termed as:
Features can vary depending on which side is affected.
May be seen as volume loss to the ipsilateral lung with and overinflation +/- herniation across the midline of the contralateral lung 4. The affected lung usually appears hyperlucent due to oligaemia, whereas the contralateral lung is supplied by a prominent pulmonary artery.
Allows direct visualization of the absence of the affected pulmonary artery. Volume loss to the affected lung is also shown. Extensive collaterals can be visualized. May allow recognition of associated cardiac anomalies.
Recognized complications include:
Treatment and prognosis
Treatment is often around the management of complications in asymptomatic individuals. There is often no commonly accepted consensus on a particular treatment strategy.
History and etymology
It is thought to have been first described by O Frantzel in 1868 3.
Plain film differential for small lung includes:
- 1. Reading DW, Oza U. Unilateral absence of a pulmonary artery: a rare disorder with variable presentation. Proc (Bayl Univ Med Cent). 2012;25 (2): 115-8. Free text at pubmed - Pubmed citation
- 3. Frantzel O. Angeborener Defect der Rechten Lungenarterie. Virchows Arch Pathol Anat. 1868; 43: 420
- 4. Werber J, Ramilo J, London R et-al. CHEST Journal. 1983;84 (6): . doi:10.1378/chest.84.6.729
- 5. Deutsch MA, Thieme SF, Hinterseer M et-al. Adult presentation of combined unilateral atresia of the right proximal pulmonary artery and left patent ductus arteriosus: case report and embryological considerations. Int. J. Cardiol. 2010;141 (1): e4-7. doi:10.1016/j.ijcard.2008.11.125 - Pubmed citation
- 6. Nakwan N. Congenital unilateral pulmonary atresia with coronary-to-pulmonary collateral artery originating from left circumflex coronary artery. Eur J Cardiothorac Surg. . doi:10.1093/ejcts/ezu223 - Pubmed citation
- 7. Koga H, Hidaka T, Miyako K et-al. Age-related clinical characteristics of isolated congenital unilateral absence of a pulmonary artery. Pediatr Cardiol. 2010;31 (8): 1186-90. doi:10.1007/s00246-010-9787-5 - Pubmed citation
- 8. Kruzliak P, Syamasundar RP, Novak M et-al. Unilateral absence of pulmonary artery: pathophysiology, symptoms, diagnosis and current treatment. Arch Cardiovasc Dis. 2013;106 (8-9): 448-54. doi:10.1016/j.acvd.2013.05.004 - Pubmed citation
- 9. Ten Harkel AD, Blom NA, Ottenkamp J. Isolated unilateral absence of a pulmonary artery: a case report and review of the literature. Chest. 2002;122 (4): 1471-7. Pubmed citation
- 10. Sankhla D, Hussein S, George J et-al. Absence of Left Pulmonary Artery: Case report. Sultan Qaboos Univ Med J. 2011;9 (2): 180-3. Free text at pubmed - Pubmed citation
- 11. Aypak C, Yıkılkan H, Uysal Z et-al. Unilateral absence of the pulmonary artery incidentally found in adulthood. Case Rep Med. 2012;2012: 942074. doi:10.1155/2012/942074 - Free text at pubmed - Pubmed citation
- 12. Ghanbari H, Feldman D, David S et-al. Unilateral absence of a left pulmonary artery: successful therapeutic response to a combination of bosentan and warfarin. Circ Cardiovasc Imaging. 2009;2 (6): e46-8. doi:10.1161/CIRCIMAGING.108.825745 - Pubmed citation
- 13. Castañer E, Gallardo X, Rimola J, Pallardó Y, Mata JM, Perendreu J, Martin C, Gil D. Congenital and acquired pulmonary artery anomalies in the adult: radiologic overview. (2006) Radiographics : a review publication of the Radiological Society of North America, Inc. 26 (2): 349-71. doi:10.1148/rg.262055092 - Pubmed
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