Medscape is available in 5 Language Editions – Choose your Edition here.


Pulmonary Artery Sling Workup

  • Author: Stuart Berger, MD; Chief Editor: Howard S Weber, MD, FSCAI  more...
Updated: Mar 04, 2014

Chest Radiography

The lower trachea is deviated to the left and may appear compressed on its right side. Hyperinflation of the right lung may be seen because of impingement on and compression of the right main stem bronchus. The left lung also may appear hyperinflated because of obstruction at the level of the carina and the left main stem bronchus. In patients with severe obstruction, atelectasis of a single lung or single lobe may be observed. The lateral view may reveal a density anterior to the esophagus and posterior to the trachea just above the carina. This is the left pulmonary artery viewed on end.


Barium Swallow

The barium swallow is the diagnostic procedure of choice. An anterior indentation of the esophagus on the lateral projection is diagnostic of pulmonary artery sling. The esophagus is usually displaced to the right in the frontal projection and demonstrates an oblique impression immediately posterior to the carina.



In the usual coronal-plane suprasternal-notch images, absence of normal bifurcation of the main pulmonary artery into right and left pulmonary arteries is visible. The left pulmonary artery appears to be absent. However, examination of the right pulmonary artery reveals the left pulmonary artery arising from its posterior surface. The left pulmonary artery can be followed posterior to the trachea and anterior to the esophagus. It passes anterior to the descending aorta and enters the hilum of the left lung. Echocardiography also reveals any associated congenital heart defects.


Magnetic Resonance Imaging and Computed Tomography Scanning

MRI or magnetic resonance angiography, CT scanning, or a combination can be helpful in delineating the details of the anatomy,[2] as well as in 3-dimensional reconstruction of the anatomy of the sling as it relates to the airway anatomy.



Bronchoscopy is generally not recommended. If performed, tracheal compression is noted, and accompanying tracheomalacia, tracheal stenosis, or both is common.[3] Some recommend bronchoscopic evaluation of selected surgical candidates because surgical reconstruction of the trachea or bronchi may be necessary if the airway compromise is severe.


Cardiac Catheterization and Angiography

The diagnosis can usually be noninvasively established. Pulmonary artery angiography may be advisable to delineate anatomic details prior to surgical correction. This permits diagnosis of variations in right and left pulmonary artery anatomy that may not be apparent from noninvasive studies and that can alter the surgical approach. Origin and course of the anomalous left pulmonary artery is best revealed by contrast injection into the main pulmonary artery filming in an oblique view with steep cranial angulation of 60 º -70 º.

Contributor Information and Disclosures

Stuart Berger, MD Medical Director of The Heart Center, Children's Hospital of Wisconsin; Associate Professor, Department of Pediatrics, Section of Pediatric Cardiology, Medical College of Wisconsin

Stuart Berger, MD is a member of the following medical societies: American Academy of Pediatrics, American College of Cardiology, American College of Chest Physicians, American Heart Association, Society for Cardiovascular Angiography and Interventions

Disclosure: Nothing to disclose.

Specialty Editor Board

Mary L Windle, PharmD Adjunct Associate Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference

Disclosure: Nothing to disclose.

Hugh D Allen, MD Professor, Department of Pediatrics, Division of Pediatric Cardiology and Department of Internal Medicine, Ohio State University College of Medicine

Hugh D Allen, MD is a member of the following medical societies: American Academy of Pediatrics, American Society of Echocardiography, Society for Pediatric Research, Society of Pediatric Echocardiography, Western Society for Pediatric Research, American College of Cardiology, American Heart Association, American Pediatric Society

Disclosure: Nothing to disclose.

Chief Editor

Howard S Weber, MD, FSCAI Professor of Pediatrics, Section of Pediatric Cardiology, Pennsylvania State University College of Medicine; Director of Interventional Pediatric Cardiology, Penn State Hershey Children's Hospital

Howard S Weber, MD, FSCAI is a member of the following medical societies: American Academy of Pediatrics, American College of Cardiology, Society for Cardiovascular Angiography and Interventions

Disclosure: Received income in an amount equal to or greater than $250 from: St. Jude Medical.

Additional Contributors

Ira H Gessner, MD Professor Emeritus, Pediatric Cardiology, University of Florida College of Medicine

Ira H Gessner, MD is a member of the following medical societies: American Academy of Pediatrics, American College of Cardiology, American Heart Association, American Pediatric Society, Society for Pediatric Research

Disclosure: Nothing to disclose.

  1. Sade RM, Rosenthal A, Fellows K, et al. Pulmonary artery sling. J Thorac Cardiovasc Surg. 1975 Mar. 69(3):333-46. [Medline].

  2. Newman B, Cho YA. Left Pulmonary Artery Sling-Anatomy and Imaging. Semin Ultrasound CT MR. 2010 Apr. 31(2):158-170. [Medline].

  3. Loukanov T, Sebening C, Springer W, et al. Simultaneous management of congenital tracheal stenosis and cardiac anomalies in infants. J Thorac Cardiovasc Surg. 2005 Dec. 130(6):1537-41. [Medline].

  4. Potts W, Holinger P. Anomalous left pulmonary artery causing obstruction to the right main stem bronchus. JAMA. 1954. 155:1409.

  5. Backer CL, Russell HM, Kaushal S, Rastatter JC, Rigsby CK, Holinger LD. Pulmonary artery sling: Current results with cardiopulmonary bypass. J Thorac Cardiovasc Surg. 2012 Jan. 143(1):144-51. [Medline].

  6. Freedom R, Culham J. The Angiography of Congenital Heart Disease. 1998.

  7. Grover FL, Norton JB Jr, Webb GE, et al. Pulmonary sling. Case report and collective review. J Thorac Cardiovasc Surg. 1975 Feb. 69(2):295-300. [Medline].

  8. Morrow R, Huhta J. Aortic arch and pulmonary artery anomalies. The Science and Practice of Pediatric Cardiology. 1990. 1444-7.

  9. Niwayama G. Unusual vascular ring formed by the anomalous left pulmonary artery, with tracheal compression. Am Heart J. 1960 Mar. 59:454-61. [Medline].

  10. Semple MG, Bricker L, Shaw BN, Pilling DW. Left pulmonary artery sling presenting as unilateral echogenic lung on 20-week detailed antenatal ultrasound examination. Pediatr Radiol. 2003 Aug. 33(8):567-9. [Medline].

  11. Tesler UF, Balsara RH, Niguidula FN. Aberrant left pulmonary artery (vascular sling): report of five cases. Chest. 1974 Oct. 66(4):402-7. [Medline].

Aberrant left pulmonary artery or pulmonary artery sling.
All material on this website is protected by copyright, Copyright © 1994-2016 by WebMD LLC. This website also contains material copyrighted by 3rd parties.