Early drain removal after hepatectomy based on bile leakage prediction using drainage fluid volume and direct bilirubin level

Aims: This study aimed to determine the value of the drainage fluid volume and direct bilirubin level for predicting significant bile leakage (BL) after hepatectomy and establish novel criteria for early drain removal. Methods: Data from 351 patients who underwent hepatic resection at Gunma University in Japan between October 2018 and March 2022 were retrospectively analyzed. Clinical characteristics and surgical outcomes of patients with and without significant BL were compared. Criteria for early drain removal were determined and verified. Results: Bile leakage occurred in 27 (7.1%) patients; 8 (2.3%) had grade A leakage and 19 (5.4%) had grade B leakage. The optimal cut-off value for the drainage fluid direct bilirubin level on postoperative day (POD) 2 was 0.16 mg/dL, which had the highest area under the curve and negative predictive value (NPV). Patients with BL had significantly larger drainage volumes on POD 2. The best cut-off value was 125 mL because it had the greatest NPV. Patients in both the primary and validation (n = 90) cohorts with bilirubin levels less than 0.16 mg/dL and drainage volumes less than 125 mL did not experience leakage. Conclusions: A drainage fluid volume less than 125 mL and direct bilirubin level less than 0.16 mg/dL on POD 2 are criteria for safe early drain removal after hepatectomy.