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PubMed This is a summary of 16 peer-reviewed journal articles Updated
Pediatric Cardiology

Mapping the Heart: Anatomical Variations

At a Glance

In babies with common arterial trunk, the way pulmonary arteries branch off the main vessel varies. Doctors use CT imaging and classification systems to map this anatomy. This acts as an exact blueprint, allowing the team to tailor the surgical repair to your baby's specific heart structure.

While every baby with common arterial trunk has a single large vessel leaving the heart, the way the smaller vessels (the pulmonary arteries) branch off that trunk can vary significantly. Doctors use specific classification systems to “map” this anatomy, which acts as a blueprint for the surgical team [1][2].

Classification Systems: Why They Matter

You may hear your cardiology team refer to medical classification systems like the Collett and Edwards system or the Van Praagh system. These sound complicated, and they often use Roman numerals and letters (like Type I, Type II, or Type A4) [3][4].

You do not need to memorize these medical categories. The most important thing to know is that these classifications help the surgical team understand exactly how your baby’s heart is “plumbed.” The doctors are looking for three main things:

  1. Where the Pipes Start: How the left and right pulmonary arteries (the pipes to the lungs) exit the main trunk. Do they branch off together from one spot, or do they originate from opposite sides? [5][4]
  2. Missing Connections: In some cases, one pulmonary artery does not come off the main trunk at all and gets its blood from a fetal blood vessel called a ductus arteriosus [6][7].
  3. Additional Gaps: A critical variant involves an interrupted aortic arch, meaning there is a gap in the main pipe that carries blood to the lower body, requiring a more complex reconstruction [8][9].

Mapping the Heart with Imaging

Knowing the exact subtype is essential for surgical success. A baby with an interrupted arch, for instance, requires a more extensive surgery to “rebuild” the arch while also repairing the trunk [10][1].

To get the most accurate map, your team will likely use high-resolution CT angiocardiography (CTA) [11]. This advanced imaging provides:

  • Preoperative Precision: It allows surgeons to see exactly where the coronary arteries (the heart’s own blood supply) are located so they can avoid them during the repair [12][13].
  • Vessel Mapping: It identifies unusual branching patterns that might not be clear on a standard ultrasound [14].
  • Surgical Tailoring: Every repair is “custom-fit” to your baby’s specific subtype to ensure the best possible blood flow to both the lungs and the body [15][16].

Common questions in this guide

Why do doctors use classification systems for common arterial trunk?
Doctors use classification systems like Collett and Edwards or Van Praagh to map exactly how your baby's pulmonary arteries branch off the main trunk. This acts as a surgical blueprint, allowing the team to plan the safest and most effective repair strategy for your child's specific anatomy.
What does it mean if my baby has an interrupted aortic arch?
An interrupted aortic arch means there is a gap in the main artery that carries blood to the lower body. If your baby has this variation, they will require a more complex, custom-tailored surgery to rebuild the arch while also repairing the common trunk.
How do surgeons see my baby's heart anatomy before surgery?
Your medical team will likely use a high-resolution CT angiocardiography (CTA) scan. This advanced imaging allows them to see the exact branching patterns of vessels and the location of coronary arteries before entering the operating room.
Will the single truncal valve need to be fixed during the surgery?
Sometimes the single truncal valve can be narrowed or leaky. Your cardiology team will assess the valve using imaging prior to the procedure to determine if it needs to be repaired or addressed during the initial surgery.

Questions to Ask Your Doctor

Curated prompts to bring to your next appointment.

  1. 1.How do the pulmonary arteries branch off my baby's main trunk?
  2. 2.Does my baby have any other anatomical variations, like an interrupted aortic arch?
  3. 3.Will the surgical team use a 3D model or advanced CT scans to plan the surgery?
  4. 4.Does the single truncal valve appear to have any narrowing or leakage that we need to address during the first surgery?

Questions For You

Tap a prompt to share your answer — we'll use it plus this page's context to start a tailored conversation.

References

References (16)
  1. 1

    Surgery for Truncus Arteriosus: Contemporary Practice.

    Naimo PS, Konstantinov IE

    The Annals of thoracic surgery 2021; (111(5)):1442-1450 doi:10.1016/j.athoracsur.2020.06.036.

    PMID: 32828754
  2. 2

    Truncus arteriosus with double aortic arch: A rare association.

    Yıldırım SV, Yıldırım A

    The Turkish journal of pediatrics 2017; (59(2)):221-223.

    PMID: 29276881
  3. 3

    Adult Female Patient with Untreated Truncus Arteriosus Type I and Torsion of Small Bowel Gastrointestinal Stromal Tumor: A Rare Case Report.

    Peng JC, Niu YH, Gao Y

    The American journal of case reports 2024; (25()):e943604 doi:10.12659/AJCR.943604.

    PMID: 38833428
  4. 4

    A rare case of truncus arteriosus Van Praagh type A3: Prenatal diagnosis and postnatal management.

    Kawasaki Y, Murakami Y, Ehara E, et al.

    Journal of cardiology cases 2019; (20(1)):30-34 doi:10.1016/j.jccase.2019.03.009.

    PMID: 31320951
  5. 5

    Acyanotic Truncus Arteriosus: Not a Misnomer But a True Rarity.

    Chellappan S, Manohar K, Sathe Y, et al.

    World journal for pediatric & congenital heart surgery 2022; (13(1)):104-106 doi:10.1177/21501351211000367.

    PMID: 33956545
  6. 6

    Staged Repair of Van Praagh Truncus Type A3.

    Ganta S, Duster N, El-Said H, et al.

    World journal for pediatric & congenital heart surgery 2021; (12(2)):286-290 doi:10.1177/2150135121990387.

    PMID: 33684014
  7. 7

    Patent ductus arteriosus stenting as therapeutic bridge in a patient with type A3 truncus arteriosus variant with multiple comorbidities.

    Hunt S, Johnston TP, Leong ME

    Cardiology in the young 2024; (34(2)):370-372 doi:10.1017/S1047951123001658.

    PMID: 37434447
  8. 8

    Repair of truncus arteriosus with interrupted aortic arch (Van Praagh type A4).

    Reyes K, Ahmed M, Brock A, Bleiweis M

    Multimedia manual of cardiothoracic surgery : MMCTS 2017; (2017()) doi:10.1510/mmcts.2017.020.

    PMID: 29300077
  9. 9

    Prenatal diagnosis of truncus arteriosus with interrupted aortic arch and abnormal limbs due to an umbilical cord amniotic band: rare entities with an unusual association.

    Guarque-Rus A, Martín-González L, Puerto-Tamayo LG, Landeyro J

    BMJ case reports 2020; (13(11)) doi:10.1136/bcr-2020-236049.

    PMID: 33148593
  10. 10

    Risk Factors and Outcomes of Perioperative Extracorporeal Membrane Oxygenation in Neonates and Infants Undergoing Truncus Arteriosus Repair.

    Suh L, Buckley JR, Hook JE, et al.

    World journal for pediatric & congenital heart surgery 2025; (16(2)):246-253 doi:10.1177/21501351241279121.

    PMID: 39449621
  11. 11

    Systematic Review of the Role of CT Angiocardiography in Enhancing the Diagnosis and Management of Truncus Arteriosus.

    Ganiyeva A, Rakhimzhanova R, Dautov T, et al.

    Medical journal of the Islamic Republic of Iran 2025; (39()):41 doi:10.47176/mjiri.39.41.

    PMID: 40740584
  12. 12

    Rare Sinusal Variant of Truncus Arteriosus with Discontinuous Pulmonary Arteries.

    Sharma A, Devkota S, Singhal M

    The Indian journal of radiology & imaging 2023; (33(3)):424-425 doi:10.1055/s-0043-1767693.

    PMID: 37362376
  13. 13

    Intramural Left Coronary Artery in Truncus Arteriosus.

    Hussein N, Speggiorin S, Bu'Lock F, Corno AF

    World journal for pediatric & congenital heart surgery 2018; (9(1)):117-120 doi:10.1177/2150135116664880.

    PMID: 27619329
  14. 14

    Imaging of the Rare Association of Truncus Arteriosus in a Neonate with the Ductal Origin of the Left Subclavian Artery Using Multidetector CT Angiography and 3D Rendering.

    Alkathiri S, Walling A, Russa DL, et al.

    Cureus 2022; (14(12)):e32131 doi:10.7759/cureus.32131.

    PMID: 36601168
  15. 15

    Outcome of truncus arteriosus repair: 20 years of single-center experience comparing early versus late surgical repair.

    Hrfi A, Ismail M, Mohammed MHA, et al.

    Cardiology in the young 2022; (32(8)):1289-1295 doi:10.1017/S104795112100408X.

    PMID: 34666851
  16. 16

    Characteristics and operative outcomes for children undergoing repair of truncus arteriosus: A contemporary multicenter analysis.

    Mastropietro CW, Amula V, Sassalos P, et al.

    The Journal of thoracic and cardiovascular surgery 2019; (157(6)):2386-2398.e4 doi:10.1016/j.jtcvs.2018.12.115.

    PMID: 30954295

This page explains common arterial trunk anatomical variations for educational purposes. Always consult your pediatric cardiologist and surgical team for details about your baby's specific heart anatomy.

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