Unexplained melena associated with a history of endovascular stent grafting of abdominal aortic aneurysms: aortoduodenal fistula

Aortoduodenal fistulas (ADFs) are rare but potentially lethal causes of massive gastrointestinal tract bleeding. Here, we report the typical endoscopic findings of ADFs.

A 57-year-old man was admitted to our hospital with intermittent melena for 2 weeks. His medical history included implantation of a prosthetic graft for an abdominal aortic aneurysm at the age of 56 years. Hemoglobin level decreased from 14.5 g/dL in the previous month to 11.2 g/dL, and esophagogastroduodenoscopy (EGD) revealed no source of bleeding up to the second part of the duodenum. On day 3, melena recurred and hemoglobin level further decreased to 9.3 g/dL. Contrast-enhanced computed tomography (CT) scan showed a protruding aorta compressing the third part of the duodenum ([Fig. 1]); EGD at this site revealed a raised lesion covered by an apparently normal mucosa with a central ulcer ([Fig. 2]). Operative findings revealed fistula formation between the aorta – at 1.5 cm from the cranial margin of the graft – and the third part of the duodenum. Gastrojejunostomy with graft replacement was performed.

Fig. 1 Computed tomogram, showing a protruding aorta compressing the third portion of the duodenum.

Fig. 2 Endoscopic image, showing a raised lesion covered by normal mucosa with a central ulcer.

ADFs are classified as either primary or secondary. Incidences of secondary ADFs after endovascular stent grafting of abdominal aortic aneurysms have been reported to be about 1 %. The duodenum, particularly its third part, is the most common site of fistula formation. Clinical manifestations include gastrointestinal bleeding, abdominal pain, and development of a pulsatile mass. Endoscopic features include a submucosal tumor with a small ulcer [1] [2] [3] [4]. Diagnosis is difficult as endoscopists do not focus on a history of aortic aneurysm repair or consider the third part of the duodenum in patients with unexplained gastrointestinal bleeding.

Endoscopy_UCTN_Code_CCL_1AB_2AZ_3AD

References

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