(Left) Graphic shows a fistula between the transverse duodenum and aorta at the site of the graft-aortic suture line .
TERMINOLOGY
Definitions
•
Abnormal communication between aorta and gastrointestinal (GI) tract
IMAGING
General Features
•
Best diagnostic clue
Inflammatory stranding and gas between abdominal aorta and 3rd part of duodenum following aneurysm repair
•
Location
Duodenum (80%); jejunum and ileum (10-15%); stomach and colon (5%)
CT Findings
•
Microbubbles adjacent to aortic graft
•
Focal bowel wall thickening &/or perigraft soft tissue thickening > 5 mm
•
Pseudoaneurysm, disruption of aneurysmal wrap
•
Contrast in pseudoaneurysm on arterial phase
•
Arterial phase: ↑ attenuation of intestinal lumen contents
Attenuation of intestinal contents may decrease on delayed phase through same region
Volume of intestinal blood may increase on delayed phase
•
CT-guided needle aspiration: May confirm perigraft infection
Nuclear Medicine Findings
•
PET/CT
Site of infection/fistula is usually FDG-avid on PET
•
Tagged RBC study
Radiolabelled RBC accumulate within bowel at site of fistula
•
Tagged WBC scan can confirm infection
Imaging Recommendations
•
Best imaging tool
CT: 94% sensitive; 85% specific
Get Clinical Tree app for offline access