Aortoenteric fistula is a rare but potentially fatal condition defined as an abnormal connection between the aorta (or aortoiliac vessels) and the gastrointestinal tract. It most commonly arises from either direct erosion of an aortic aneurysm (primary AEF) or as a complication of an aortic prosthetic graft (secondary AEF).
- Cause
- Primary Aortoenteric Fistula
- Occurs de novo, typically due to an aneurysm, infection, malignancy, radiation, or foreign body.
- Over 75% involve the third and fourth parts of the duodenum
- Secondary Aortoenteric Fistula
- Occurs after aortic surgery, usually from mechanical graft erosion or infection. It most commonly affects the duodenum, though it can involve other bowel segments.
- Other causes
- Esophageal causes: Reflux esophagitis
- Peptic ulcer disease
- Duodenal pathology: Erosion of a distal duodenal diverticulum into the aorta
- Pancreatic pathology: Pancreatic pseudocyst
- Gastrointestinal malignancy
- Vascular intervention-related: Erosion of embolization coils
- Infectious causes: Septic, nonaneurysmal aortitis
- Surgical complications: Remote complications of Billroth II gastric resection
- Aortic pathology: Penetrating aortic ulcer
- Endoscopic intervention-related: Enteral stenting
- Foreign bodies
- Paraaortic radiation
- Rare infectious and inflammatory causes: Syphilis, tuberculosis, bacterial or fungal aortic infection, collagen vascular disease
- Primary Aortoenteric Fistula
- Presentation
- Massive GI hemorrhage from direct aortic-bowel communication.
- Occult bleeding, intermittent but progressive.
- Sepsis due to graft infection without bleeding.
- The “herald bleed” (a small self-limiting GI bleed before massive exsanguination) is a key warning sign
- Clinical triad: bleeding, abdominal pain, and a palpable abdominal mass
- Unreliable