Preoperative risk factors for conversion from laparoscopic to open cholecystectomy: a validated risk score derived from a prospective U.K. database of 8820 patients

HPB (Oxford). 2016 Nov;18(11):922-928. doi: 10.1016/j.hpb.2016.07.015. Epub 2016 Aug 31.


Background: Laparoscopic cholecystectomy is commonly performed, and several factors increase the risk of open conversion, prolonging operating time and hospital stay. Preoperative stratification would improve consent, scheduling and identify appropriate training cases. The aim of this study was to develop a validated risk score for conversion for use in clinical practice.

Patients and methods: Preoperative patient and disease-related variables were identified from a prospective cholecystectomy database (CholeS) of 8820 patients, divided into main and validation sets. Preoperative predictors of conversion were identified by multivariable binary logistic regression. A risk score was developed and validated using a forward stepwise approach.

Results: Some 297 procedures (3.4%) were converted. The risk score was derived from six significant predictors: age (p = 0.005), sex (p < 0.001), indication for surgery (p < 0.001), ASA (p < 0.001), thick-walled gallbladder (p = 0.040) and CBD diameter (p = 0.004). Testing the score on the validation set yielded an AUROC = 0.766 (p < 0.001), and a score >6 identified patients at high risk of conversion (7.1% vs. 1.2%).

Conclusion: This validated risk score allows preoperative identification of patients at six-fold increased risk of conversion to open cholecystectomy.

Publication types

  • Multicenter Study
  • Validation Study

MeSH terms

  • Adult
  • Age Factors
  • Aged
  • Chi-Square Distribution
  • Cholecystectomy, Laparoscopic / adverse effects*
  • Common Bile Duct / diagnostic imaging
  • Common Bile Duct / pathology
  • Common Bile Duct / surgery*
  • Conversion to Open Surgery*
  • Databases, Factual
  • Digestive System Diseases / diagnostic imaging
  • Digestive System Diseases / pathology
  • Digestive System Diseases / surgery*
  • Dilatation, Pathologic
  • Female
  • Gallbladder / diagnostic imaging
  • Gallbladder / pathology
  • Gallbladder / surgery*
  • Humans
  • Logistic Models
  • Male
  • Middle Aged
  • Multivariate Analysis
  • Odds Ratio
  • Predictive Value of Tests
  • Prospective Studies
  • Reproducibility of Results
  • Risk Assessment
  • Risk Factors
  • Sex Factors
  • Treatment Outcome
  • United Kingdom