Routine White Test for Early Detection of Bile Leak in Elective Liver Resection (DELiveR Trial)

Bile leakage is a clinically important complication following liver resection and is associated with increased postoperative morbidity, need for reintervention and prolonged hospitalisation. The White Test involves retrograde injection of a white lipid emulsion into the biliary tree to facilitate active identification of open bile ducts on the liver transection surface. However, the benefit and safety of its routine use across different types of liver resection remain uncertain.

The DELiveR Trial is a single-centre, prospective, randomised, parallel-group, participant- and outcome-assessor-blinded superiority trial. A total of 270 adults undergoing elective major or minor liver resection will be randomised in a 1:1 ratio to the White Test or a standardised white gauze assessment.

Final eligibility will be confirmed intraoperatively after confirmation of resectability, completion of liver parenchymal transection and haemostasis, and confirmation that a cystic duct or cystic duct stump can be safely approached for attempted cannulation. Randomisation will then be performed using a computer-generated sequence with permuted blocks and concealed allocation.

The White Test will involve slow, manual, low-pressure retrograde injection of 10-20 mL of SMOFlipid 5%, with temporary distal bile duct occlusion. Injection will be discontinued if abnormal resistance is encountered. Identified leakage sites will be clipped, ligated or sutured. The control group will undergo a standardised white gauze assessment according to a study-specific operating procedure.

All participants will have an intra-abdominal drain placed. Serum and drain-fluid bilirubin concentrations will be measured concurrently on postoperative day 3. Participants will be followed for 30 days.

The primary outcome is postoperative bile leakage within 30 days according to the International Study Group of Liver Surgery definition. The primary analysis will be conducted in the overall intention-to-treat population using logistic regression. Major versus minor hepatectomy will be evaluated only in exploratory subgroup and interaction analyses.

Secondary outcomes include clinically relevant grade B/C bile leakage, postoperative morbidity, major morbidity, reinterventions, intensive care unit use, hospital length of stay, readmission, mortality and potential intervention-related adverse events. An independent Data and Safety Monitoring Committee will periodically review safety data.