Here is the design of a clinical trial:

Official Title: Diagnostic Role of the "White Test" With Lipidic Solution in the Early Intraoperative Identification of Open Bile Ducts for the Prevention of Bile Leakage After Liver Resection- A Randomized Controlled Multicentric Superiority Trial- The BiLe-Trial (Bile Leakage Trial)

Included conditions:
- Bile Leakage

Study Armgroups:
- {'label': 'Experimental Intervention (treatment)', 'type': 'EXPERIMENTAL', 'description': 'Open bile ducts are identified by visual control of the liver resection surface combined with the direct injection in the cystic stump of 20-40ml of SMOFlipid 20% Fresenius Kabi Canada Ltd.; authorization number: 57231 (Swissmedic).\n\nSMOFlipid is a white oily emulsion containing soya oil and medium chain triglycerides as main active components, normally used as parenteral nutrition as complement for essential fat acids supplementation. In this study the "white" test (= the administration of SMOFlipid retrograde through the cystic duct) is made by injection of one or two 20cc syringes full of lipidic solution (SMOFlipid 20%) in the cystic stump, directing the flow to the intrahepatic ducts. Residual fat emulsion is washed out from the biliary tract by a low pressure infusion of 20 to 50 ml of saline solution.', 'interventionNames': ['Drug: "white" test" (= the administration of SMOFlipid retrograde through the cystic duct)']}
- {'label': 'Control Intervention', 'type': 'NO_INTERVENTION', 'description': 'Open bile ducts are identified in the control group by visual control of the liver resection surface combined with the use of white gauzes (standard procedure)'}

Interventions:
- {'type': 'DRUG', 'name': '"white" test" (= the administration of SMOFlipid retrograde through the cystic duct)', 'description': '"white" test" (= the administration of SMOFlipid retrograde through the cystic duct)', 'armGroupLabels': ['Experimental Intervention (treatment)']}

Primary Outcomes:
- {'measure': 'rate of postoperative bile leakage', 'description': 'Comparison of the rate of postoperative bile leakage in the control and in the intervention group. This is a binary endpoint defined by the presence or absence of the bile leakage (yes or no). Bile leakage is defined as bilirubin concentration in the drain fluid at least 3 times the serum bilirubin concentration on or after postoperative day 3.', 'timeFrame': 'within 30 days postoperative'}

Please estimate the sample size based on the assumption: 
Statistical power of 80%, significance level of 0.05, no interim analysis planned.
Sample size calculation
          The BiLe-Trial is designed as a superiority trial, hypothesising that the intraoperative performance of the white test with lipidic solution reduces the rate of postoperative bile leakage compared with the use of a white gauze applied on the resected liver surface.
          The sample size was determined via simulations of the primary analysis. The simulations were based on the assumption that the intraoperative use of the white test with SMOFlipid 5% will lead to a postoperative reduction of the bile leakage rate from 21% in the control group (Nadalin et al and our retrospective data) to 7% in the intervention group. To detect this difference with a statistical power of 80% using Pearsonâs Ï2 test (with continuity correction) at a two-sided 0.05 significance level a sample size of 105 patients was required for each group, which means that 210 patients should be included in the study. No interim analysis is planned. The assumptions about the bile leakage rates were derived from evidence in the literature in conjunction with experience at hospitals participating in the study and currently using one of the studied treatments. The Cantonal Hospital Aarau is currently using the control treatment and saw a bile leakage rate of 19% among patients undergoing liver resection of two or three segments during the past years. A prospective cohort study of patients undergoing major (ie, at least three segments) liver resection found a bile leakage rate of 22.9% for the control group.8 The same cohort study found a bile leakage of 5.3% for the treatment group and also another observational study found a similar bile leakage rate of 5.1% among patients undergoing major liver resection surgery with lipidic solution.7 By contrast, the Cantonal Hospital of St. Gallen is routinely using lipidic solution in addition to standard methods and estimated their bile leakage rate at 10%. Hence, for both study groups, we assume a bile leakage rate that lies in between those observed.