Tzovaras 2012.

Methods	Randomised controlled clinical trial Randomisation ratio: superiority design Interim analysis of the first 100 randomised patients
Participants	100 patients with cholecysto‐choledocholithiasis; one patients from the control group withdrew consent after randomisation; mean age: 67.5 years; male: 46.5%; median common bile duct diameter: 9 mm; mean BMI: 27; ASA I: 51.5%, II: 37.5%, III: 11% Inclusion criteria: people with stones in gallbladder and CBD Exclusion criteria: age < 18 years, ASA status IV and V, BMI > 35, previous ERCP attempt, history of upper abdominal surgery, and pregnancy Diagnostic criteria: gallbladder and main bile duct stones were detected by both transabdominal ultrasound and MRCP
Interventions	Number of study centres: one Treatment before study: not reported Type of interventions: 50 patients treated in a single step with videolaparoscopic cholecystectomy, intraoperative cholangiography, and endoscopic sphincterotomy during the surgical procedure with the rendezvous technique versus 49 treated with preoperative ERCP and endoscopic sphincterotomy using a traditional method of bile duct cannulation
Outcomes	Mortality, morbidity, conversions, clinical pancreatitis, serum amylase, failure rate, hospital stay (days)
Notes	Run‐in period: from September 2006 to April 2009 Study terminated before regular end (for benefit or because of adverse events): no Follow‐up: not reported Funding sources: no information reported Declaration of interest: none declared Country: Greece
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Randomization created by a computer‐generated list in blocks of 20 patients.
Allocation concealment (selection bias)	Low risk	Sealed envelopes
Blinding of participants and personnel (performance bias) All outcomes	High risk	Participants and personnel were not blinded.
Blinding of outcome assessment (detection bias) All outcomes	High risk	Not clearly stated whether the outcomes assessors were blinded to the treatments or not.
Incomplete outcome data (attrition bias) All outcomes	Low risk	One patient from the control group withdrew consent after randomisation.
Selective reporting (reporting bias)	Low risk	The trial was registered at one of the available official sites for clinical trials registration (ClinicalTrials.gov ID: NCT00416234).
Other bias	Low risk	Interim analysis planned after completion of the first 100 patients
for‐profit bias	Unclear risk	Information about sponsorship or trial support not reported

ERCP = endoscopic retrograde cholangiopancreatography; LERV = laparoscopic‐endoscopic rendezvous; CBD = common bile duct; MRCP = magnetic resonance cholangiopancreatography; ASA = American Society of Anesthesiologists; BMI = body mass index; AST = aspartate aminotransferase