CASE 13599 Published on 15.04.2016
0

Interrupted aortic arch type A subtype 1

Section

Cardiovascular

Case Type

Clinical Cases

Authors

Ahmed M. Osman, MD, Basant Mohamed Raief, Ms. C., Asmaa Mahmoud Naguib, Ms. C.

Ain Shams University hospital,
Radiology Department;
38 Ramsis Street
EL Abbasia, CAIRO, Egypt.
Tel: 002/0224821728,
Fax:002/0224821728.
Website: http://med.shams.edu.eg.
E. mail: dr_aosman@med.asu.edu.eg
E. mail: dr_osman80@yahoo.com
Connected authors
Patient

22 years, male

Categories
Area of Interest Arteries / Aorta ; Imaging Technique Catheter arteriography, CT-Angiography
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Clinical History
A male patient, 22 years old, smoker, hypertensive, complained of dyspnoea and chest pain. ECG showed widespread concave ST segment elevation. Echo revealed mild left ventricular concentric hypertrophy with preserved systolic function. Cardiac catheterization failed to opacify the whole aorta. CT aortic angiography was requested pre and post-operatively.
Imaging Findings
The trans-femoral catheter failed to pass proximal to the level of the descending thoracic aorta (Fig. 1a) followed by trans-axillary approach with failure to opacify the descending thoracic aorta with normal coronaries (Fig. 1b). The patient underwent CT aortography using injector for the contrast media injection via a cannula followed by image post processing. An interrupted aortic arch noticed by fibrous septum seen just distal to the origin of the left SCA (type A) with normal right SCA (subtype 1) with no PDA (Fig. 2 & 4). Two main anastomotic channels noted opacification of the aorta distal to the level of interruption. The first was along the anterior abdominal wall between the superior epigastric arteries and the inferior epigastric arteries (Figure 3 & 4). The second was along the lumbar and posterior intercostal arteries (Fig. 3). Post-operative study revealed aortic correction with stent application (Fig. 5).
Discussion
IAA represents approximately 1% of congenital heart disease cases [1], first described in 1778 and first surgically repaired in 1954 [2]. IAA is defined as a lack of luminal continuity along the aorta; either complete or by an atretic fibrous band [1].

It is associated with other cardiovascular anomalies in more than 98% of cases, with the commonest being patent ductus arteriosus (PDA) [1]. It can be associated with a single ventricle, ventricular septal defect (VSD), left ventricular outflow tract obstruction, anomalous right subclavian artery (SCA), aortopulmonary window, truncus arteriosus, and/or transposition of the great arteries and bicuspid aortic valve [3].

The exact cause is matter of debate with most theories depending on the supposition that blood flow during embryogenesis directly affects the development and involution of blood vessels and therefore causes abnormally decreased blood flow through the aortic arch, contributing to the IAA development [4]. Another theory is chromosomal anomalies with chromosome 22q11.2 deletion found in about 50% of cases [5, 6].

Classification of IAA described by Celoria and Patton:
Type A: Distal to the left SCA (1/3 of cases).
Type B: Between the left SCA and the left common carotid artery (most common; nearly 2/3 of cases).
Type C: Between the left carotid artery the innominate artery (least common) [6].

Furthermore, each type can be subdivided into type 1 and 2 based on the anatomy of the right SCA, whether normal or aberrant, situated retroesophageally (present in 50% of type B, but also may be seen in type A) [7-8].

Infants usually remain clinically stable as long as the PDA remains open. Cardiogenic shock and multiorgan dysfunction appears with PDA closure [6]. Isolated cases often go undetected into adolescence or early adult life, and then appear with a clinical picture similar to a postductal coarctation [1].

The role of imaging is important for surgery planning to determine the location and length of the interruption, calibre of the aorta proximal and distal to the interruption, pattern and origin of the great vessels, presence and absence of PDA as well as other congenital anomalies [4].

The treatment is IV prostaglandin therapy to preserve the PDA followed by one stage surgical correction with direct aortic arch primary anastomosis (end-to-end or end-to-side) with or without placement of synthetic graft and possible VSD repair. A multistage repair is needed in cases with complex congenital heart disease [9-11]. The mortality rate with the repair is approximately 8% [10].
Differential Diagnosis List
Interrupted aortic arch type A subtype 1
Severe aortic corctation
Neonatal arterial thrombosis
Final Diagnosis
Interrupted aortic arch type A subtype 1
Case information
URL: https://www.eurorad.org/case/13599
DOI: 10.1594/EURORAD/CASE.13599
ISSN: 1563-4086
License

This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.

Figure 1

Cardiac catheter

Cardiac catheter
Trans-femoral cardiac catheter reveals non-passage of the catheter proximal to the level of descending thoracic aorta which is opacified with non-opacification of the aorta proximally.
Cardiac catheter
Trans-axillary cardiac catheterization reveals non-passage of the catheter distal to the level of the junction between the arch and descending aorta with non-opacified descending thoracic aorta.
Figure 2

Pre-operative coronal and sagittal CT aortic angiography

Pre-operative coronal and sagittal CT aortic angiography
Coronal CT aortography reformatted images revealed interrupted aortic arch at the level between the arch of the aorta and the descending aorta distal to the left SCA with a complete fibrous band (arrowed).
Pre-operative coronal and sagittal CT aortic angiography
Sagittal CT aortography reformatted images revealed interrupted aortic arch at the level between the arch of the aorta and the descending aorta distal to the left SCA with a complete fibrous band (arrowed).
Figure 3

Pre-operative coronal and sagittal CT aortic angiography

Pre-operative coronal and sagittal CT aortic angiography
Coronal CT aortography reformatted images revealed anterior anastomotic channels between the superior and inferior epigastric artery connecting the IMA proximally to the CFA distally. Notice the abnormal dilatation of the IMA (arrowed).
Pre-operative coronal and sagittal CT aortic angiography
Sagittal CT aortography reformatted images revealed anterior anastomotic channels between the superior and inferior epigastric artery connecting the IMA proximally to the CFA distally. Notice the abnormal dilatation of the IMA (arrowed).
Pre-operative coronal and sagittal CT aortic angiography
Sagittal CT aortography reformatted images revealed posterior anastomotic channels along the posterior intercostal arteries.
Figure 4

Pre-operative CT aortic angiography: 3D volume rendering images

Pre-operative CT aortic angiography: 3D volume rendering images
3D VR images. White arrow refers to the IAA seen distal to the left SCA (blue arrow) (type A). Yellow arrows refer to the anterior anastomotic channels with dilated internal mammary arteries (red arrow).
Pre-operative CT aortic angiography: 3D volume rendering images
3D VR images. White arrow refers to the IAA seen distal to the left SCA (blue arrow) (type A). Yellow arrows refer to the anterior anastomotic channels with dilated internal mammary arteries (red arrow)
Figure 5

Post-opertaive CT angiography

Post-opertaive CT angiography
Sagittal reformatted CT aortic angiography image showing a stent inserted at the level of the interrupted aortic arch.
Post-opertaive CT angiography
Curved multi-planar reformatted CT aortic angiography image showing a stent inserted at the level of the interrupted aortic arch.
Post-opertaive CT angiography
3D volume rendering CT aortic angiography image showing a stent inserted at the level of the interrupted aortic arch.