Intravascular gas in the transplanted kidney: a sign of extensive graft necrosis.

We encountered a case of transplanted kidney necrosis, with computed tomography (CT) demonstrating multiple areas of intravascular gas within the allograft. The intravascular gas represented air emboli from gas liberated from fermentation by gas-forming organisms in a perinephric abscess. Arterial bleeding accelerated by the wound infection and the resultant large perinephric hematoma caused renal infarction. Gas-forming infection of transplanted organs is associated with a poor graft outcome, which can present as a fulminant clinical course. Intravascular gas should be distinguished from collecting system gas because the former could represent extensive necrosis of the transplanted kidney.