Routine Intraoperative White Test for Bile Leak Detection in Liver Resection

Bile leakage (BL) remains one of the most frequent complications following liver resection and is associated with increased postoperative morbidity and mortality, higher reintervention rates, prolonged hospital stay, and increased healthcare costs. Effective intraoperative identification and closure of open bile ducts may reduce the risk of postoperative BL. The White Test, which involves retrograde injection of a lipid emulsion into the biliary tree, enables active detection of bile leaks during surgery; however, its routine use has not been established in randomized clinical trials across all types of liver resection.

This is a single-center, prospective, randomized, parallel-group, single-blinded superiority trial designed to evaluate the effectiveness of routine intraoperative use of the White Test compared with standard intraoperative bile leak detection using a white gauze test. Adult patients undergoing elective liver resection (major or minor, including both anatomic and non-anatomic resections) who meet eligibility criteria will be enrolled after providing written informed consent.

Participants will be randomized in a 1:1 ratio to either the intervention group (White Test) or the control group (standard gauze test), using stratified block randomization according to the type of resection (major vs minor). Allocation will be concealed using sequentially numbered, opaque, sealed envelopes. Patients will remain blinded to group assignment, while the operating surgeon cannot be blinded due to the nature of the intervention.

In the intervention group, following completion of liver parenchymal transection and achievement of hemostasis, the cystic duct stump will be identified and cannulated. The distal bile duct will be temporarily occluded, and 10-20 mL of lipid emulsion will be injected retrogradely into the biliary tree. The transection surface will be inspected for leakage of the white emulsion. Identified leaks will be managed by ligation or suturing, and the test may be repeated until no further leakage is observed. In the control group, bile leak detection will be performed by applying sterile white gauze to the transection surface with visual inspection, followed by suturing of identified leaks as needed.

All patients will have intra-abdominal drainage placed at the resection site. Drain fluid bilirubin concentration will be measured on postoperative day three. Patients will be followed for 30 days after surgery.

The primary outcome is the incidence of postoperative bile leakage within 30 days, defined according to the International Study Group of Liver Surgery (ISGLS) criteria. Secondary outcomes include severity of bile leakage (ISGLS grades A-C), postoperative morbidity (Clavien-Dindo classification), need for postoperative interventions (endoscopic, radiological, or surgical), intensive care unit (ICU) admission and length of ICU stay, and total hospital length of stay.

The primary analysis will follow the intention-to-treat principle and will be performed separately within strata defined by resection type (major vs minor). Secondary and subgroup analyses will be considered exploratory. No formal interim analysis is planned; however, patient safety will be continuously monitored throughout the study.

The results of this trial are expected to clarify the role of routine intraoperative White Test in liver surgery and its potential to reduce postoperative bile leakage and improve clinical outcomes.