[en] Postoperative complications seriously threaten graft and patient survival. Prompt diagnosis and treatment of these complications is of critical importance. In clinical differentiation of rejection from hepatic dysfunctions such as biliary obstruction, studies of allograft perfusion and bile flow with radionuclides are helpful. Cholescinti-graphy is specially used to diagnose bile leakage. Focal fluid collections such as biliomas, hematomas and seromas are seen with relative frequency after liver transplantation. Directed fine needle aspiration differentiates all these cases and is able to document infection. (author). 25 refs.; 5 figs.; 1 tab