[Secondary aorto-enteral fistula as a cause of acute recurrent gastrointestinal bleeding, 20 years after living kidney donation].

Aorto-enteral fistulas (AEF) are a rare but life-threatening cause of acute gastrointestinal bleeding. Clinically, they can appear through massive haematochezia and haematemesis or as intermittent occult intestinal bleeding. The diagnostic procedure using endoscopy is often difficult but can contribute to making the correct diagnosis. We report on a patient who developed a secondary aorto-enteral fistula twenty years after a living kidney donation. The vascular surgery in combination with a chronic inflammatory reaction had resulted in the formation of a fistula between the renal artery stump and the duodenum. The inflammatory response was maintained by continuous treatment with methotrexate because of rheumatoid arthritis. Despite several total enteroscopies and diagnostic laparotomies, the fistula was seen on several occasions but was overlooked and misinterpreted in the absence of bleeding at first. The suspected fistula was finally marked with two endoclips and confirmed subsequently by radiological imaging by means of an abdominal CT scan.