Direct Bilirubin in Drainage Fluid 3 days after Hepatectomy Is Useful for Detecting Severe Bile Leakage

Introduction: The International Study Group of Liver Surgery (ISGLS) definition of bile leakage is an elevated total bilirubin concentration in the drainage fluid after post-operative day (POD) 3, which has been widely accepted. However, there were no reports about direct bilirubin in drainage fluid to predict bile leakage. Methods: Data from 257 patients who underwent hepatectomy were retrospectively reviewed. The optimal cut-off value was investigated using receiver-operating characteristic curves. The predictive power of drainage fluid total bilirubin (dTB) and drainage fluid direct bilirubin (dDB) to predict bile leakage, which was defined using ISGLS grade B or grade C, were compared. Results: ISGLS grade B bile leakage occurred in 16 patients (6.2%). Area under the curve (AUC) of dDB was always higher than that of dTB on each POD. The AUC of dDB was >0.75 on PODs 2, 3, and 5, and then it increased with the increasing POD. The dDB on POD 5 showed the highest accuracy (0.91) and positive predictive value (PPV) (0.67), which was followed by dTB/serum total bilirubin (sTB) on POD 3 (accuracy, 0.91; PPV, 0.33). Because the PPV of dDB increased as the POD increased, dDB was better than dTB for predicting clinically significant bile leakage. dDB on POD 3 showed the highest negative predictive value (0.97). The positive likelihood of dDB increased and the negative likelihood of dDB decreased on the basis of the POD. Among patients with dTB/sTB ≤3 on POD 3, 19.1% of these patients had bile leakage when dDB was >0.44 on POD 3. Conclusions: Measurement of both dDB and dTB, which are easy to perform, can be used to effectively predict clinically significant bile leakage.