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Interrupted aortic arch (IAA) is a rare and critical congenital malformation characterized by a complete loss of luminal continuity between the ascending and descending aorta. It represents the most severe form of aortic arch obstruction, and is incompatible with life without ductal flow and early intervention.

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![Part of the Aorta is absent and this leads to severe obstruction to blood flow to the lower part of the body. In the immediate newborn period blood flows through the 'Ductus' into the Descending Aorta and hence reaches the lower part of the circulation. As the ductus closes after birth blood pressure in the lower circulation becomes inadequate and severe symptoms develop. Most affected infants develop severe symptoms (difficulty breathing and impaired kidney function) in the first week of life and need urgent surgery

Cardiology : Interrupted Aortic Arch. Rch.org.au. Published 2025. Accessed July 11, 2025. https://www.rch.org.au/cardiology/heart_defects/Interrupted_Aortic_Arch/](attachment:db462560-c1cc-4e50-9ae2-b420699fb5ff:11a_Interrupted_aortic_arch.jpg)

Part of the Aorta is absent and this leads to severe obstruction to blood flow to the lower part of the body. In the immediate newborn period blood flows through the 'Ductus' into the Descending Aorta and hence reaches the lower part of the circulation. As the ductus closes after birth blood pressure in the lower circulation becomes inadequate and severe symptoms develop. Most affected infants develop severe symptoms (difficulty breathing and impaired kidney function) in the first week of life and need urgent surgery

Cardiology : Interrupted Aortic Arch. Rch.org.au. Published 2025. Accessed July 11, 2025. https://www.rch.org.au/cardiology/heart_defects/Interrupted_Aortic_Arch/

Classification

Celoria and Patton classification system:

• Based on site of interruption relative to the major branches of the aortic arch

![Schematic figure of the three subtypes of IAA based on the location of the interrupted segment: Type A, interruption distal to the origin of the left subclavian artery; Type B, interruption between the origins of the left common carotid artery and left subclavian artery; Type C, interruption between the origins of the right brachiocephalic artery and left common carotid artery. IAA: interrupted aortic arch.

Bae SB, Kang EJ, Choo KS, Lee J, Kim SH, Lim KJ, Kwon H. Aortic Arch Variants and Anomalies: Embryology, Imaging Findings, and Clinical Considerations. J Cardiovasc Imaging. 2022 Oct;30(4):231-262. https://doi.org/10.4250/jcvi.2022.0058](attachment:1d0c17be-d665-4387-99de-c81115c2edb9:jcvi-30-231-g025-l.jpg)

Schematic figure of the three subtypes of IAA based on the location of the interrupted segment: Type A, interruption distal to the origin of the left subclavian artery; Type B, interruption between the origins of the left common carotid artery and left subclavian artery; Type C, interruption between the origins of the right brachiocephalic artery and left common carotid artery. IAA: interrupted aortic arch.

Bae SB, Kang EJ, Choo KS, Lee J, Kim SH, Lim KJ, Kwon H. Aortic Arch Variants and Anomalies: Embryology, Imaging Findings, and Clinical Considerations. J Cardiovasc Imaging. 2022 Oct;30(4):231-262. https://doi.org/10.4250/jcvi.2022.0058

Embryology

• Abnormal regression or failure of development of the fourth aortic arch segments
• Often associated with defects in neural crest cell migration
• Associated with ventricular septal defect (VSD) and patent ductus arteriosus (PDA)

Pathophysiology

• Systemic blood flow to lower body depends on PDA
• As the ductus closes, infants develop:
  • Severe acidosis
  • Shock
  • Multiorgan failure
• Survival depends on ductal patency and intracardiac shunting

Clinical Presentation