In this retrospective study, we aimed to detect of effects of ERCP on outcomes of Laparoscopic Cholecystectomy. Patients underwent elective cholecystectomy surgery with a diagnosis of symptomatic cholelithiasis were identified and divided into two main groups regarding to have a ERCP procedure prior to surgery or not. To eliminate possible differences in baseline characteristics, patients in ERCP and non-ERCP groups were propensity score-matched 1:1 using nearest-neighbor matching without replacement based on age, sex and ASA score. Following propensity score matching (PSM), the ERCP and non-ERCP groups were first compared to detect effects of the ERCP procedure itself. After comparison of two main groups, subgroup analyzes performed for the ERCP group to detect effect of ERCP-related variables (indication for ERCP procedure, time between last ERCP procedure and surgery, number of preoperative ERCPs, stone extractions, and biliary stent use)

All patients aged 18 years and over who underwent elective cholecystectomy surgery with a diagnosis of symptomatic cholelithiasis and whose surgery was started laparoscopically in a single tertiary reference hospital between January 1, 2016 and January 1, 2020 were identified retrospectively using the hospital data. Patients with a diagnosis of malignancy, with a history of percutaneous cholecystostomy, who underwent cholecystectomy while being operated for a different indication, and those who were diagnosed with cholecystoenteric fistula during the operation, were excluded from the study. After exclusion, patients first divided to two groups regarding to have a ERCP procedure prior to surgery or not. Age, sex, ASA scores, history of previous abdominal surgery, Charlson Comorbidity Index (CCI) values were included as baseline data. In terms of CCI scores, patients categorized into two subgroups according to CCI scores greater than 3 or not. To eliminate possible differences in baseline characteristics, patients were propensity score-matched 1:1 using nearest-neighbor matching without replacement based on age, sex and American Society of Anesthesiologists (ASA) score. Following propensity score matching (PSM), the ERCP and non-ERCP groups were first compared to detect effects of the ERCP procedure itself.

The primary outcomes examined in our study were conversion to open and subtotal cholecystectomy, intraoperative adhesion levels and operative time, hospital stay and postoperative complications. Only complications that have a Clavien-Dindo Score greater or equal to 3 were noted as postoperative complication for analyzes. While the patients with no adhesions were considered as group A, the patients with adhesions covering less than 50% of the gallbladder were considered as group B, whereas the patients in whom the gallbladder was completely covered with adhesions were considered as group C.

After comparison of two main groups, subgroup analyzes performed for the ERCP group to detect effect of ERCP-related variables to the same outcomes. The variables used in each separate subgroup analysis in the ERCP group were as follows: indication for ERCP procedure, time between last ERCP procedure and surgery, number of preoperative ERCPs, stone extractions, and biliary stent use. Information about mechanical lithotripsy was also noted and used for a separate subgroup analysis

For the first subgroups analysis, ERCP group divided into two subgroups regarding the preoperative ERCP indication was cholangitis or not. The second subgroup analysis was based on the ERCP-Laparoscopic cholecystectomy interval and three subgroups determined. Accordingly, for the timing of surgery, the first two weeks after ERCP were classified as early interval, the 2nd and 6th weeks as moderate interval, and the 6 weeks or later after ERCP, as late interval. Each of the number of preoperative ERCPs, extracted stones, and placed biliary stents were also used determinants for shaping the other subgroups. For the design of the last subgroup, patients were divided into two subgroups according to whether or not they had mechanical lithotripsy in their preoperative ERCP.

Inclusion Criteria:

• All patients aged 18 years and over who underwent elective cholecystectomy surgery with a diagnosis of symptomatic cholelithiasis and whose surgery was started laparoscopically

Exclusion Criteria:

• Patients with a diagnosis of malignancy, with a history of percutaneous cholecystostomy, who underwent cholecystectomy while being operated for a different indication, and those who were diagnosed with cholecystoenteric fistula during the operation, were excluded from the study.

After exclusion, patients first divided to two groups regarding to have a ERCP procedure prior to surgery or not. Age, sex, ASA scores, history of previous abdominal surgery, Charlson Comorbidity Index (CCI) values were included as baseline data. In terms of CCI scores, patients categorized into two subgroups according to CCI scores greater than 3 or not. To eliminate possible differences in baseline characteristics, patients were propensity score-matched 1:1 using nearest-neighbor matching without replacement based on age, sex and American Society of Anesthesiologists (ASA) score. Following propensity score matching (PSM), the ERCP and non-ERCP groups were first compared to detect effects of the ERCP procedure itself.

The participant data are not publicly available due to institutional policies but are available from the corresponding author on reasonable request