Primary iliac-sigmoid fistula after diverticulitis: A rare case report and literature review

Aortoenteric fistulae (AEF) is a rare but life-threatening condition. They can be classified as primary (spontaneous, PAEF) or secondary (after aortic reconstructions). Most of the PAEFs involve the duodenum and the small bowel. Because of their rareness, the diagnosis is difficult and can sometimes be missed, with lethal consequences. In fact, PAEFs overall mortality reaches 50% and remains dramatically high even after intervention 30–40%. We report a case of 68-year old man, admitted to Emergency Department for abdominal pain and rectal bleeding. An intravenous contrast-enhanced abdomen CT scan reported an infrarenal and left iliac aneurysm with a replenished hematoma which displaced the sigmoid colon and a fluid collection in the left psoas muscles. He underwent a percutaneous EVAR procedure and a later CT angiography showed a suspected communication between the sigmoid colon and the hematoma. Thus, we performed Hartmann's procedure with debridement of the abdominal cavity. The literature review reported 19 cases of aortic or iliac-sigmoid fistula. Six patients were treated by endovascular means. Regardless of care, eight patients died during the operation or in the early post-operative phase. Open surgery remains the gold standard of the treatment for PAEFs, however bridge endovascular approach should be considered as lifesaving strategy in non-elective setting.