One-step laparoscopic cholecystectomy with common bile duct exploration and stone extraction versus two-step endoscopic retrograde cholangiography with stone extraction plus laparoscopic cholecystectomy for patients with common bile duct stones: a randomised feasibility and pilot clinical trial—the preGallStep trial
Authors: Kirkegaard-Klitbo Anders , Shabanzadeh Daniel Mønsted , Olsen Markus Harboe , Lindschou Jane , Gluud Christian , Sørensen Lars Tue 
Published: February 2023

Abstract
Background
Endoscopic retrograde cholangiography (ERC) with stone extraction and papillotomy with subsequent laparoscopic cholecystectomy—the two-step approach—is the standard treatment of common bile duct stones in many countries. However, ERC is associated with a high risk of complications and more than half of patients require multiple ERCs. Meta-analyses of randomised clinical trials find no major differences of the two-step approach in comparison with laparoscopic cholecystectomy with intraoperative laparoscopic stone clearance—the one-step approach. Currently, there are insufficient data to ascertain superiority.

Methods
The preGallstep trial is an investigator-initiated, multicentre randomised feasibility and pilot clinical trial with blinded outcome assessment. Eligible patients are patients with common bile duct stones (identified by magnetic resonance cholagiopancreatography), age 18 years or above with the possibility to perform both interventions within a reasonable time. We intent to randomise 150 participants allocated 1:1. The experimental intervention is the one-step approach. This consists of laparoscopic common bile duct exploration plus laparoscopic cholecystectomy. The control intervention is the two-step approach which consists of ERC plus sphincterotomy (first step) and subsequent laparoscopic cholecystectomy (second step). Feasibility outcomes include the proportion of eligible patients not wanting to participate, reasons for rejection to participate, difficulties during the informed consent procedure, difficulties with randomisation, difficulties with data management, difficulties with blinding patient charts and forms and difficulties with maintaining blinding for the outcome assessors. The primary pilot outcome is the proportion of participants with at least one postoperative complication according to the Clavien-Dindo score grade II and above until 90 days after randomisation. This outcome will be used for a future sample size calculation of a larger pragmatic trial. Further, a range of clinical explorative outcomes will be assessed.

Discussion
As no sample size is estimated in this trial, there is a risk of wrongly assessing the effect on the patient-related outcome. The surgical procedures cannot be blinded. However, blinding will be employed in all other aspects of the trial, including the establishment of a blinded outcome adjudication committee with three independent assessors. Heterogeneity in screening, randomisation, diagnostics, treatment procedures, interventions and follow-up across trial sites may cause challenges in conducting a larger pragmatic trial. To monitor inter-site differences, we have implemented a central data monitoring scheme.

Trial registration
ClinicalTrials.gov identification: NCT04801238, Registered on 16 March 2021