Primary and secondary aortoenteric fistulas in a patient with abdominal aortic aneurysm.

Introduction: Aortoenteric fistulas (AEF) are infrequent malignant complications of abdominal aortic aneurysms (AAA). We present a unique case of a patient with recurring AAA fistulisations.

Presentation Of Case: During oncologic treatment, a 63-year-old male was incidentally diagnosed with infrarenal AAA and assigned follow-up but was hospitalised with anaemia and elevated inflammation markers 14 months later. A CT-angiography scan detected an AAA enlargement, but no extravasation (negative FOBT). Another CTA-scan displayed a pseudoaneurysm and ruptured AAA 10 days later. During a total laparotomy, an enlarged pulsating inflammatory conglomerate without active leakage was detected, with a 2 cm duodenal defect (PAEF). The AAA was resected and replaced by a linear silver-coated Dacron graft. 3,5 years after PAEF, the patient was hospitalised with abdominal pain and haematemesis. He underwent gastroscopies, coloscopies, CT- and CTA-scans - all without significant findings. Only after the capsule-endoscopy detected a jejunal ulcer, the PET-scan visualized active regions in the jejunum and the aortic graft. A total laparotomy was performed; previous stapler-lined jejuno-jejunal anastomosis had adhered to the silver-coated Dacron graft (SAEF). The Dacron graft was removed and replaced with a linear xenograft from bovine pericardium.

Discussion: No evidence-based recommendations prefer endovascular aneurysm repair (EVAR) over open repair, leaving the strategy dependent on local preferences. Whether EVAR or initial xenograft usage would have shown surpassing results, is speculative, as no graft material/type has proved long-term pre-eminence.

Conclusions: This case displays AEF's complex treatment and challenging diagnosis. Multimodal diagnostic and strategic approaches should be considered for best patient outcome.