Teaching Case

A 79-year-old male patient with fever and haematemesis came to our Emergency Department. Naso-gastric tube was placed and fresh red blood clots from active bleeding were drained. Emergency imaging was required.

Chest X-ray showed an important enlargement of the right side of the upper mediastinum (Fig. 1). In five hours haemoglobin decreased gradually from 11.9 to 8.3 g/dL, and a Sengstaken-Blakemore tube was placed trying to control haemorrhage and prevent further anaemisation. Because of the progressive worsening of patient’s health condition and to study the X-ray finding a MDCT examination was performed. It showed a large aberrant right subclavian artery aneurysm (maximum diameter 10 cm) extended for 14 cm from the aortic origin of the vessel (Fig. 2, 3). It was characterised by a huge thrombotic part with small air bubbles inside (Fig. 2), highly indicative of oesophageal fistula. The vascular lumen of the subclavian artery was in paper-thin contact with the posterior oesophageal wall. No active bleeding was recognised in MDCT examination because of the presence of the Blakemore tube.

Aberrant right subclavian artery (ARSA), also called “lusorian artery”, is a well known anatomical variant of the origin of the right subclavian artery, one of the most common congenital vascular abnormalities of the aortic arch (the prevalence among the population is 1-2% in according to different authors) [1-4]. Usually ARSA arises after the left subclavian artery and crosses the mediastinum behind the oesophagus and the trachea. For its particular position ARSA can cause compression to the close anatomical structures. Dysphagia lusoria is the most frequent symptom (in 10 % of cases). For the same reason the prolonged compression caused by medical devices such as nasogastric or endotracheal tubes on the arterial wall of the ARSA can cause severe injury, especially when an ARSA aneurysm is present. In rare cases it can lead up to an oesophageal fistula with profuse bleeding characterised by high mortality rate (till now less than 20 cases were reported in literature). In our case fistulisation was not due to an iatrogenic cause but spontaneous. Best way to explore these patients in acute situations is contrast-enhanced MDCT, because often these patients are not stable enough to sustain an oesophago-gastro-duodenoscopy. In our case we did not see an active bleeding because of the presence of Blakemore tube.