A Singh, B Baruah, U Garga, R Tiwari
aortic arch anomalies, dysphagia lusoria, kommerell diverticulum
A Singh, B Baruah, U Garga, R Tiwari. Dysphagia Lusoria. The Internet Journal of Radiology. 2008 Volume 10 Number 1.
We report an interesting case of Dysphagia lusoria due to aberrant left subclavian artery with discussion of aortic arch anomalies.
A 45 yr old woman presented with dysphagia for solids for 1 year. There was no history of oynophagia, heartburn, epigastric discomfort, retrosternal pain or vomiting.
Barium Swallow was done. On AP view, Right extrinsic impression was noted and on lateral view posterior impression was seen.
Chest X Ray was done after that and Right sided aortic arch was found.
We made a presumptive diagnosis of Right sided aortic arch with extrinsic impression on posterior and right lateral aspect of upper thoracic esophagus due to some aberrant vessel.
No structural abnormality of heart was found on Echocardiography.
Contrast Enhanced CT was done and Right sided aortic arch with aberrant left subclavian artery was noted.
AA: Aortic Arch, SCA : Left Subclavian Artery, KD: Kommerell diverticulum.
MRA was done subsequently and the findings were confirmed. No evidence of vascular ring was noted.
Dysphagia Lusoria is a term given to difficulty in swallowing due to compression of esophagus by aberrant course of subclavian artery.
The Incidence of developmental anomalies of the aortic arch and its major branches is 3% (1), but they are usually asymptomatic. Aortic arch anomalies may become symptomatic when they completely “ring” the trachea and esophagus (1). The trachea is compressible during infancy, and these patients typically present when solid foods are introduced, with respiratory symptoms: stridor, wheezing, cyanosis, or recurrent pneumonia. The esophagus is more likely to be compressed in adults because of rigid trachea.
The aortic arches are a series of six paired embryological vascular structures which give rise to several major arteries. They are ventral to the dorsal aorta.
Right aortic arch is present when the left fourth arch involutes and the right remains.
Anomalies of aortic arch can be classified as :
LEFT AORTIC ARCH WITH ABERRANT RIGHT SUBCLAVIAN ARTERY
Most common major variation in the aortic arch and its branching pattern.
Ba Swallow: Left lateral and posterior impression
Right Aortic arch (4)
Type I: Descending aorta on right side of spine.
Type II: Descending aorta on left side of spine.
Type I and II are again subdivided acc. to the branching pattern
TYPE Ia/IIa : Left inominate artery, RCA, RSA : MIRROR IMAGE TYPE
Most usual form of right aortic arch to be found in association with cyanotic heart disease.
TYPE Ib/IIb: LCA, RCA, RSA with aberrant left subclavian artery
Incidence is 0.05 % (3). Proximal dilated portion of aberrant vessel is known as Kommerell diverticulum.
Ba Swallow: Right lateral and posterior except in Ia in which compression is usually not seen.
Double Aortic Arch
Most common cause of a symptomatic vascular ring in children
Ba Swallow: Bilateral impression. Right arch is larger and higher and left arch is smaller and lower
Berdon and Baker classified vascular induced esophageal indentation into four patterns (2):
Chest x-ray a) Position of aortic arch
b) Indentation of trachea
BA Swallow : Screening method and frequently the diagnosis of vascular ring is initially made with ba swallow
ECHO: It is important in ruling out any structural heart disease
CECT: It is a sensitive modality for vascular rings but the disadvantage is its radiation hazard especially in children in whom vascular ring is frequently suspected.
MRI: Cardiovascular MRA is the modality of choice. It has become a new gold standard at some institutions as it is noninvasive and uses no radiation (5).
Angiography: It was the gold standard but MRI has replaced it.
Bronchoscopy: Bronchoscopy allows a more precise evaluation of degree and nature of compression, depending on the type of vascular ring or sling.