DYSPHAGIA LUSORIA : A LATE ONSET PRESENTATION

Dysphagia lusoria is the term used to describe dysphagia following vascular compression of oesophagus. Diagnosis can be made by barium and contrast enhanced CT SCAN. The present case describes a late on set dysphagia secondary to aberrant right subclavian artery.


Introduction:
Dysphagia Lusoria is an abnormal condition characterised by difficulty in swallowing (dysphagia) caused by a vascular compression of the right subclavian artery to oesophagus also known as Bayford-Autenrieth dysphagia.First case was discovered in 1761 by David Bay Ford (1) .Describing a longstanding case of dysphagia leading to emaciation and eventual death of a 62-year-old female on autopsy patient found to have aberrant right subclavian artery.Majority of the case ARSA runs posterior to cause oesophageal compression and dysphagia (3) .This is the most common anomaly of the aortic arch, representing 17% of this malformation group and the incidence of aberrant right subclavian artery ranges from 0.2% to 2.5%.The symptoms are usually silent and mostly it as an incidental finding at necropsy (5) .In the present case describes a late onset dysphagia due to aberrant right subclavian artery.

History:
An 83-year-old male subject presented to the ENT department with difficulty in swallowing (dysphagia) to solids, foreign body sensation in throat and food sticking sensation.There was no significant medical history as well as family history reported.No weight loss was reported.Past medical history and physical examination was unremarkable.

Methods:
Current case was reported in ENT Department and after a detail case history was obtained along with physical examination.Then the case was referred for Routine blood examination, chest x-ray, barium swallow examination, CT Scan and ECG.

Result:
Routine blood examination, chest x-ray and ECG all were well within normal range.Then the patient subjected for barium swallow examination which reveals normally appearing pharynx and upper oesophagus.Posterior esophagal impression detected in the upper oesophagus.A contrast CT demonstrates an aberrant right subclavian originating from the lower third of aortic arch and it is traversing posterior to oesophagus.
As an empirical way of treatment proton pump inhibitors and domperidone were introduced getting certain occasional symptomatic relief.
Since the patient age and other comorbidities forced us to propel away from any other vascular reversion procedures.Patient was advised follow certain lifestyle and nutritional modifications.ARSA is a common variant of embryonic aortic arch involution within the general population (3) .This occurs as a consequence of a persistent 7th intersegmental artery with involution of 4th vascular arch with the right dorsal aorta ( 4, 5).Majority of the cases aberrant artery traverses posterior to the oesophagus but in a small proportion it may run anterior to the oesophagus, as in the original description of the syndrome by BAYFORD (1) .Certain times Kommerell's diverticulum accompanies the ARSA (3) .In rare eventualities kommerell's diverticulum may become aneurismal with subsequent oesophageal compression and dysphagia (6,7) .
Haesemeyer etal conducted a study in 7174 trauma patients along with CT scan and found 29 ARSA cases (8) .Another study conducted by Abhaichand et al in 3730 patients underwent for trans radial coronary angiography and found 14 cases with ARSA (9) .Fockens etal done endoscopic ultrasound for 1629 subjects and fond 6 cases of ARSA (10) .Kelly (11) found a single case out of 223 patients subjected for upper GI endoscopy for dysphagia.
Aberrant subclavian arteries are present on routine endoscopy as a pulsatile posterior indentation in the upper oesophagus, however endoscopic diagnosis is rare.Majority of cases are from right subclavian originating from left sided aortic arch, similar abnormality is also possible from a left aberrant subclavian extending from right sided aortic arch, however which is much rarer (13,14) .This anomaly develops when the right dorsal artery remains patent and either the left arch or left dorsal aorta regresses abnormally.
A complete vascular ring is formed when the left ductus arteriosus associated with ARSA, where left sided ductus arteriosus passing from left subclavian artery to the proximal left pulmonary artery.Majority presented with dysphagia for solid foods (3) .Sometimes it remains dormant and incidentally detected following investigations done for other conditions.Dynamic barium swallow studies and vascular reconstruction studies done by using modalities like CT and MRI help us to plan for vascular reversal surgeries if at all needed.Late onset symptoms can be attributed to dysmotility disorders of oesophagus, stiffening of the vessel due to atherosclerosis and aortic elongation with increased traction on the obstructing vessel and aneurysmal dilatations in the presence of Kommerell's diverticulum (2) .
Management depends on the severity of the dysphagia and the ability of the patients to maintain a proper weight and nutrition.Almost half of the (50%) of the cases can be managed by dietary modifications and rephase the chewing habits.Severe symptomatic patients not responding to interventional dietary and swallowing strategies may warrant surgical treatment.Gross (17) first reported surgical management of this condition describing the division and ligation of aberrant right subclavian artery, in a 4-month-old child Via thoracotomy.Lichter (18) described surgery on an adult patient left postero-lateral thoracotomy.
Our case presented with late onset dysphagia due to ARSA managed with dietary and swallowing modifications, surgical line of management not needed.

Funding:
There is no funding.

Consent:
Written informed consent was obtained from the patient for publication of this case report and accompanying images.

Figure 1 :
Figure 1: Barium swallow AP View shows impression in upper posterior wall of oesophagus by aberrant right subclavian artery

Figure 3 :
Figure 3: figure 2 nd and 3 rd shows CECT Chest, ARSA originating from right aortic arch, leaving an impression behind the posterior oesophageal wall Discussion: