Aorto-enteric fistulas can be:

1. Primary: by rupture aorta through aorto-enteric fistula into a closely adherent portion of gastrointestinal tract with bleeding.
2. Secondary: to complication of vascular prostheses or intestinal diseases.

The most frequent location of aorto-enteric fistula is the third duodenal segment (D3).

Courtesy: Dott.ssa Sara Zanzani