The volume of free subdiaphragmatic gas is out of proportion with the length of time since the operation seven days ago. The presence of air-fluid levels also suggests free intraperitoneal fluid. Together, this may represent primary anastomotic breakdown or leak. The patient returned to theater where the anastomotic leak was confirmed.
For patients without contrast at the anastomotic site the most significant CT feature of an anastomotic leak is loculated fluid containing gas adjacent to the anastomotic site 1.