An 84-year-old man presented to the emergency department with dizziness and epigastric pain radiating to his back. He was pale and diaphoretic with a systolic blood pressure of 85 mm Hg. A CT scan of the abdomen revealed features consistent with primary aortoenteric fistula (PAEF) (fig 1). The patient underwent urgent surgical repair and made a full recovery.

• Download figure
• Open in new tab
• Download powerpoint

Figure 1 CT scan of the abdomen following administration of intravenous contrast medium showing an infrarenal abdominal aortic aneurysm with thrombosis of the aneurysmal lumen (large arrow) with gas in the thrombus (small arrow).

PAEF is an uncommon cause of gastrointestinal blood loss which is rapidly fatal if early diagnosis is not made.1 The classic triad of gastrointestinal bleeding, pulsatile abdominal mass and pain is present in only 11% of cases;2 30% of patients experience a “herald bleed” prior to massive haemorrhage.2 CT scanning has a detection rate of 61%.2 Radiographic features include gas in the aortic wall, contrast in the bowel lumen, focal bowel wall thickening and disruption of aortic fat cover. Management includes cautious fluid resuscitation and urgent surgical repair.