The document discusses various vascular anomalies of the chest that can occur due to abnormalities in the development of the aortic arch system and pulmonary veins in embryos. It describes conditions like double aortic arch where both arches encircle the trachea and esophagus, coarctation of the aorta where there is narrowing of the descending aorta, and total anomalous pulmonary venous return where the pulmonary veins drain into structures other than the left atrium. It also provides diagrams and links to further explain these different vascular anomalies.

1. Vascular Anomalies of the Chest
J. Paul Nielsen, MD, MPH

2. Aortic Arches
• The aortic arches are a series of
paired arterial channels encircling
the embryonic pharynx
 Develop in the 4th week
 Supply the developing
pharyngeal arches
 Arise from the aortic sac
 Run dorsally, embedded in the
mesenchyme of the pharyngeal
arches and
 Terminate in the right and left
dorsal aortae

5. Arch of Aorta
Derived as:
• Proximal segment
from aortic sac
• Middle segment from
the left 4th aortic arch
• Distal segment from
the left dorsal aorta

6. Subclavian Artery
• The right subclavian
artery formed from the:
 Right 4th aortic arch
 Right dorsal aorta
 Right 7 th
intersegmental
artery
• The left subclavian
artery formed from the
left 7th intersegmental
artery

7. Changes in the original aortic arch system
• Obliteration of:
• Most of the 1st & 2nd arches
• 5th arches completely
• Distal part of the right sixth
arch
• The segment of both aorta
lying between the 3rd & 4th
arches
• The segment of right aorta
lying between the 7th
intersegmental artery & the
fused dorsal aorta

8. Aortic Arch Anomalies
• Due to many changes involved in transformation
of the embryonic pharyngeal arch system of
arteries into the adult arterial pattern
• Most irregularities result from the persistence of
parts of aortic arches that usually disappear, or
from disappearance of parts that normally
persists

10. Vascular Rings
• malformation of the aortic arch that results in
vascular branches or major blood vessels
encircling the trachea and esophagus.
• True rings: Double aortic arch (most
common), double aortic arch with atretic left
segment, right sided arch with abberant left
subclavian
• In a double aortic arch, the two arches
encircle the trachea and esophagus.

11. Other non-true ring arch
abnormalities
• left arch with abberant right subclavian
(most common arch abnormality), Mirror
image right arch, aortic coarctation,
common origin of brachiocephalic and left
common carotid artery (bovine
configuration.), brachiocephalic artery
compression.

13. http://radiopaedia.org/articles/aortic-arch-variants

14. Double Arch of Aorta
• Characterized by a vascular
ring encircling the trachea
and esophagus, usually
causing compression of both
structures.
• The degree of compression
varies
• Usually the right arch is RCC LCC
larger and passes posterior
to the esophagus RSA LSA
• The right common carotid
and subclavian arteries arise
separately from right arch

17. Brachiocephalic artery
compression syndrome

20. Pulmonary Artery
• Sling
Pulmonary sling occurs because of failure of
formation of Left 6th aortic arch so there is absence of
Left pulmonary artery
• The blood to the Left lung comes from an aberrant
Left pulmonary artery which arises from Right
pulmonary artery and crosses between esophagus
and trachea
• Bronchial cyst may produce same finding on
esophagus/trachea
• http://radiopaedia.org/articles/pulmonary-sling

22. Spin Echo MR

24. Coarctation of Aorta
• Abnormality of the 4th and 6th arch
• An infantile coarctation is characterised by diffuse hypoplasia or narrowing of the aorta from
proximal to the ductus arteriosus, associated with cyanosis of lower extremities due to left to
right shunting through the PDA
• An adult coarctation in contrast is characterised by a short segment abrupt stenosis of the
post-ductal aorta. It is due to thickening of the aortic media and typically occurs just distal
ligamentum arteriosum (remnant of the ductus arteriosus), non-cyanotic, p/w lower extremity
hyPOtension
• Complications: Bacterial endocarditis common in 1st 5 decades, Aortic rupture 2~3rd decade
subarachnoid hemorrhage(congenital Berry aneurysm)

25. Figure 8. Tubular hypoplasia (preductal or infantile-type aortic coarctation).
Ferguson E C et al. Radiographics 2007;27:1323-1334
©2007 by Radiological Society of North America

26. Figure 7. Localized (postductal or adult-type) aortic coarctation.
Ferguson E C et al. Radiographics 2007;27:1323-1334
©2007 by Radiological Society of North America

28. Transposition of the Great
Arteries
• Transposition of the great arteries, the most common cyanotic congenital heart
lesion found in neonates, accounts for 5%–7% of congenital cardiac
malformations.
• It is most common in infants of diabetic mothers. It is isolated in 90% of those
affected and rarely is associated with a syndrome or an extracardiac
malformation.
• in transposition of the great arteries, the pulmonary artery is situated to the
right of its normal location and is obscured by the aorta on frontal chest
radiographs. This malposition, in association with stress-induced thymic atrophy
and hyperinflated lungs, results in the apparent narrowing of the superior
mediastinum on radiographs, the most consistent sign of transposition of the
great arteries.

31. Total anomalous pulmonary
venous return
• The pulmonary veins fail to drain into the left atrium and instead form an aberrant connection
with some other cardiovascular structure.
• Four types of TAPVR thus may be defined.In type I, the most common of the four (55% of
cases), the anomalous pulmonary veins terminate at the supracardiac level. Typically, four
anomalous pulmonary veins (two from each lung) converge directly behind the left atrium and
form a common vein, known as the vertical vein, that passes anterior to the left pulmonary
artery and the left main bronchus to join the innominate vein.
• Less commonly, anomalous drainage to the left brachiocephalic vein, the right superior vena
cava, or the azygos vein occurs.

32. Total anomalous pulmonary
venous return
• Type II TAPVR (30% of cases) involves a pulmonary venous connection at the cardiac level. The
pulmonary veins join either the coronary sinus or the right atrium.
• Type III TAPVR (13% of cases) involves a connection at the infracardiac or infradiaphragmatic
level. The pulmonary veins join behind the left atrium to form a common vertical descending
vein, which courses anterior to the esophagus and passes through the diaphragm at the
esophageal hiatus. This vertical vein usually joins the portal venous system but occasionally
connects directly to the ductus venosus, the hepatic veins, or the inferior vena cava. Type III
TAPVR is virtually always accompanied by some degree of obstructed venous return.
• Type IV TAPVR involves anomalous venous connections at two or more levels. In the most
common pattern, the vertical vein drains into the left innominate vein, and the anomalous vein
or veins from the right lung drain into either the right atrium or the coronary sinus. This
pattern generally is associated with other major cardiac lesions.

35. Partial anomalous pulmonary
venous return
• anomalous pulmonary vein that drains any or all of the
lobes of the right lung. The so-called scimitar vein usually
empties into the inferior vena cava but also may drain into
the portal vein, hepatic vein, or right atrium

40. The End

41. Links to cases
• http://radiopaedia.org/articles/aortic-arch-
variants
• http://radiopaedia.org/articles/pulmonary-
sling

42. Sources
1. Aortic Arches. Zaidi, Zeenat.
http://www.docstoc.com/docs/125362680/12-Aortic-Arches
2. Berdon WE. Rings, slings, other things: vascular compression of the infant trachea
updated from the midcentury to the millennium – the legacy of Robert E. Gross, MD,
and Edward B. D. Neuhauser, MD. Radiology 2000;216:624–32
3. http://www.radiologyassistant.nl/en/p4718c7f2eb7cc/vascular-anomalies-of-aorta-pulmonary-and-s
4. http://www.hawaii.edu/medicine/pediatrics/pemxray/v6c19.html
5. Classic imaging signs of congenital cardiovascular abnormalities.
http://radiographics.rsna.org/content/27/5/1323.full