Interesting case Abdominal 33

Salient findings:

• Aortofemoral bypass.

• At the level of the graft bifurcation, there is contrast extravasation into the horizontal segment of the duodenum, in keeping with graft erosion resulting in aortoenteric fistula.

• Couple of tiny locules of gas adjacent to the inferior aspect of the bifurcation.

• Filling of the small bowel loops with contrast progressively on the portal venous phase.

• Dilation of small bowel loops throughout the abdomen in keeping with ileus, with complete collapse of the colon.

Principle Diagnosis:

Secondary aorto-enteric fistula.

Other important findings:

Striated enhancement of bilateral kidneys with poor thready opacification of bilateral renal arteries in keeping with multiple renal infarcts.

Learning points:

Primary vs Secondary aortoenteric fistulas, depending on whether there has been aortic surgery +/- graft.

Direct and indirect signs can be seen:

DIRECT:

• Intravascular contrast seen within the GI tract

• Ectopic gas either within or closely related to the aortic graft

INDIRECT:

• Haematoma within the mediastinum or retroperitoneum

• In the presence of an aortic aneurysm, thickening of the adjacent or overlying loop of bowel (or oesophagus).

• Thickening and increased soft tissue surrounding the graft or aneurysm suggesting inflammation or infection