Pulmonary artery sling
| Pulmonary artery sling | |
|---|---|
| Specialty | Cardiology |
Pulmonary artery sling (PAS) is a rare congenital vascular anomaly where the left pulmonary artery (LPA) originates abnormally from the right pulmonary artery (RPA) instead of the main pulmonary artery. This aberrant course causes the LPA to pass between the trachea and esophagus.[1] PAS caused by an embryological malformation and is frequently associated with other congenital anomalies, particularly affecting the airway and heart. Advanced imaging techniques such as CT, MRI, echocardiography, and bronchoscopy are essential for diagnosing PAS and identifying associated abnormalities. Surgical repair in early childhood is the standard treatment, aimed at relieving airway compression and correcting the other associated defects.
The term "vascular sling" comes from the configuration where the LPA compresses distal trachea and right mainstem bronchus as it courses between the trachea and esophagus to reach the left lung. This anomaly is classified as a type of vascular ring, though it doesn't form a complete ring around the airway and esophagus.[2]
Pulmonary artery sling was originally written about in 1897 by Glaevecke and Doehle.[3] The first known case PAS was diagnosed and surgically repaired in 1953 by Dr. Willis J. Potts at Lurie Children's Hospital (formerly Children's Memorial Hospital). He performed the procedure on a 5-month-old infant. Although the surgery was technically successful, follow-up imaging revealed limited blood flow to the left lung, highlighting the early challenges of managing this complex anomaly.[2][4]
Embryology and Associated Anomalies
[edit]PAS arises due to abnormal embryologic development, specifically a failure of proper formation of the left sixth aortic arch.[2] As a result, the left pulmonary artery (LPA) originates anomalously from the right pulmonary artery (RPA), which retains its normal position. The LPA then takes an aberrant course: it arises anterior to the right main bronchus near its origin from the trachea, then passes between the trachea and esophagus before reaching the left pulmonary hilum. This aberrant path forms the characteristic vascular sling, which can compress the airway and lead to significant clinical symptoms.[5]
Pulmonary artery sling is frequently associated with other congenital anomalies including: tracheal anomolies, cardiovascular anomalies, gastrointestinal anomalies, and others.[6][7][8]
Tracheal stenosis also known as tracheomalacia and complete tracheal rings are the most commonly associated congenital anomalies in patients with PAS. Approximately 50% to 79% of patients with PAS have congenital tracheal stenosis due to the presence of complete cartilaginous tracheal rings, which can significantly contribute to airway obstruction and respiratory symptoms.[9][10][11]
Approximately 30% of patients with PAS have associated congenital cardiac anomalies. Commonly associated defects include atrial septal defect (ASD), ventricular septal defect (VSD), tetralogy of Fallot (TOF), and aortic coarctation.[9][6][12] Other cardiovascular anomalies include left superior vena cava, aberrant right subclavian, coarctations.[8] Among these, tetralogy of Fallot is the most frequently associated anomaly.[11] Other cardiovascular abnormalities that may be present include a persistent left superior vena cava, aberrant right subclavian artery, and coarctation of the aorta.[8]
Gastrointestinal anomalies associated with PAS may include duodenal atresia, biliary atresia, Meckel’s diverticulum, and Hirschsprung disease. These coexisting abnormalities can further complicate the clinical picture and may require additional evaluation and management.[7][8]
Right lung agenesis may also occur in association with PAS, often accompanied by failure of development of the right mainstem bronchus, further contributing to respiratory compromise. Additionally, PAS can be part of broader syndromic associations, including VACTERL syndrome (Vertebral defects, Anal atresia, Cardiac anomalies, Tracheoesophageal fistula, Renal anomalies, and Limb abnormalities). Other genetic syndromes reported in association with PAS include Down syndrome, Holt-Oram syndrome, and Kartagener syndrome, indicating the importance of comprehensive genetic and systemic evaluation in affected patients.[7][12]
Symptoms & Evaluation
[edit]Patients with PAS often become symptomatic in infancy or early childhood with the majority presenting within the first year of life.[13] The condition typically causes airway compression due to the abnormal origin and course of the left pulmonary artery (LPA), which passes between the trachea and esophagus. Most symptoms are not specific, however, common symptoms can include: mild tachypnea, respiratory distress, stridor, wheezing, recurrent respiratory infections, feeding difficulties, cyanosis (especially in severe cases).[1]
Because PAS is an anatomical defect and frequently associated with other congenital anomalies advanced imaging is essential for accurate diagnosis and evaluation.
All patients with PAS should undergo cross-sectional imaging such as CT or MRI to define vascular anatomy and identify associated anomalies. Given the common association with tracheal stenosis and complete tracheal rings, bronchoscopy is necessary to assess airway anatomy, mucosal detail, dynamic changes, and extrinsic compression.[4] However, significant narrowing may limit the bronchoscope's ability to pass beyond the stenotic segment—making CT crucial for evaluating the distal airway.
Most diagnosis of PAS are made from echocardiography.[12] An echocardiogram is also indicated to assess for associated congenital heart defects, which are present in a significant number of cases.[9] While PAS is often first detected on echocardiography, a full diagnostic work-up—including CT, bronchoscopy, and echocardiography—is essential for surgical planning and management.
Treatment
[edit]Early recognition of PAS is essential, as the severity of airway obstruction can vary and may necessitate surgical intervention. Surgery is typically performed via open-heart approach through a median sternotomy.[4] All patients diagnosed with PAS should undergo a comprehensive preoperative work-up to determine the need and timing for surgical repair. The majority of surgical repairs are performed in neonates and infants, particularly those with congenital tracheal stenosis. The median age at surgery is between 7 to 9 months, though the range can span from 6 days to 27 months.[7][12]
The primary goal of PAS is to LPA so that it no longer passes between the trachea and esophagus, thereby relieving airway compression. It is also critical to maintain adequate and durable blood flow to the left lung. Associated anomalies, such as congenital tracheal stenosis or intracardiac defects, can often be addressed during the same surgical procedure.
There are two main techniques are used for surgical correction of PAS: (1) Reimplantation of the LPA into the main pulmonary artery and (2) Tracheal transection with LPA translocation. Surgical access can be achieved via median sternotomy or a left thoracotomy approach.[12] A 2012 study demonstrated that Pulmonary Artery Sling (PAS) is best repaired using a median sternotomy, cardiopulmonary bypass, and left pulmonary artery (LPA) reimplantation, which resulted in uniformly patent LPAs in all patients.[9]
References
[edit]- ^ a b K. Rahmath, Muhammed Riyas; Durward, Andrew (2023). "Pulmonary artery sling: An overview". Pediatric Pulmonology. 58 (5): 1299–1309. doi:10.1002/ppul.26345. ISSN 8755-6863. PMID 36790334.
- ^ a b c Lee, Madonna; Landsem, Leah (2025), "Pulmonary Artery Sling", StatPearls, Treasure Island (FL): StatPearls Publishing, PMID 32965870, retrieved 2025-06-12
- ^ Carlson, Laura; Haider, Mahwish; Liu, Hua; Baird, Christopher; Mayer, John E.; Nathan, Meena (2021). "Left Pulmonary Artery Sling: Postoperative Outcomes for Patients at a Single Center". World Journal for Pediatric and Congenital Heart Surgery. 12 (6). SAGE Publications: 715–727. doi:10.1177/21501351211040741. ISSN 2150-1351. PMID 34846972.
- ^ a b c Backer, Carl L. (2020). "Vascular Rings and Pulmonary Artery Sling". In Raja, Shahzad G. (ed.). Cardiac Surgery: A Complete Guide. Springer. p. 981. ISBN 978-3-030-24174-2. OCLC 1142507832.
- ^ Berger, Stuart (March 22, 2020). "Pulmonary Artery Sling: Background, Pathophysiology, Epidemiology". Medscape Reference. Retrieved January 22, 2024.
- ^ a b Hirsig, Leslie E.; Sharma, Priya G.; Verma, Nupur; Rajderkar, Dhanashree A. (2018). "Congenital Pulmonary Artery Anomalies: A Review and Approach to Classification". Journal of Clinical Imaging Science. 8: 29. doi:10.4103/jcis.JCIS_9_18. ISSN 2156-7514. PMC 6085843. PMID 30147993.
- ^ a b c d Harada, Atsushi; Shimojima, Naoki; Shimotakahara, Akihiro; Azuma, Saya; Ishizuka, Yoshiaki; Tomita, Hirofumi; Hirobe, Seiichi (December 2019). "Surgical indication for congenital tracheal stenosis complicated by pulmonary artery sling". Journal of Thoracic Disease. 11 (12): 5474–5479. doi:10.21037/jtd.2019.11.31. ISSN 2072-1439. PMC 6987985. PMID 32030266.
- ^ a b c d Newman, Beverley; Cho, Young ah (April 2010). "Left pulmonary artery sling--anatomy and imaging". Seminars in Ultrasound, CT, and MR. 31 (2): 158–170. doi:10.1053/j.sult.2010.01.004. ISSN 0887-2171. PMID 20304323.
- ^ a b c d Backer, Carl L.; Russell, Hyde M.; Kaushal, Sunjay; Rastatter, Jeffrey C.; Rigsby, Cynthia K.; Holinger, Lauren D. (January 2012). "Pulmonary artery sling: current results with cardiopulmonary bypass". The Journal of Thoracic and Cardiovascular Surgery. 143 (1): 144–151. doi:10.1016/j.jtcvs.2011.09.038. ISSN 1097-685X. PMID 22050985.
- ^ Yong, Matthew S.; Zhu, Michael Z. L.; Bell, Douglas; Alphonso, Nelson; Brink, Johann; d'Udekem, Yves; Konstantinov, Igor E. (2019-01-31). "Long-term outcomes of surgery for pulmonary artery sling in children". European Journal of Cardio-Thoracic Surgery: Official Journal of the European Association for Cardio-Thoracic Surgery. doi:10.1093/ejcts/ezz012. ISSN 1873-734X. PMID 30715328.
- ^ a b Atkins, Marvin D.; Fuller, Stephanie (February 2018). "Thoracic Surgery Considerations in the Child and Young Adult". Thoracic Surgery Clinics. 28 (1): 43–52. doi:10.1016/j.thorsurg.2017.08.005. ISSN 1558-5069. PMID 29150036.
- ^ a b c d e Fiore, Andrew C.; Brown, John W.; Weber, Thomas R.; Turrentine, Mark W. (January 2005). "Surgical treatment of pulmonary artery sling and tracheal stenosis". The Annals of Thoracic Surgery. 79 (1): 38–46, discussion 38–46. doi:10.1016/j.athoracsur.2004.06.005. ISSN 1552-6259. PMID 15620911.
- ^ François, Katrien; Panzer, Joseph; De Groote, Katya; Vandekerckhove, Kristof; De Wolf, Daniel; De Wilde, Hans; Marchau, Fabienne; De Caluwe, Wim; Benatar, Abraham; Bové, Thierry (March 2017). "Early and late outcomes after surgical management of congenital vascular rings". European Journal of Pediatrics. 176 (3): 371–377. doi:10.1007/s00431-017-2850-y. ISSN 1432-1076. PMID 28091779.