title: Conversion from laparoscopic to open cholecystectomy: multivariate analysis of preoperative risk factors.
abstract: BACKGROUND
  Laparoscopic cholecystectomy has become the gold standard in the treatment of symptomatic cholelithiasis. Some patients require conversion to open surgery and several preoperative variables have been identified as risk factors that are helpful in predicting the probability of conversion. However, there is a need to devise a risk-scoring system based on the identified risk factors to (a) predict the risk of conversion preoperatively for selected patients, (b) prepare the patient psychologically, (c) arrange operating schedules accordingly, and (d) minimize the procedure-related cost and help overcome financial constraints, which is a significant problem in developing countries.
  
  
  OBJECTIVE
  This study was aimed to evaluate preoperative risk factors for conversion from laparoscopic to open cholecystectomy in our setting.
  
  
  METHODS
  A case control study of patients who underwent laparoscopic surgery from January 1997 to December 2001 was conducted at the Aga Khan University Hospital, Karachi, Pakistan.
  
  
  METHODS
  All those patients who were converted to open surgery (n = 73) were enrolled as cases. Two controls who had successful laparoscopic surgery (n = 146) were matched with each case for operating surgeon and closest date of surgery.
  
  
  METHODS
  Descriptive statistics were computed and, univariate and multivariate analysis was done through multiple logistic regression.
  
  
  RESULTS
  The final multivariate model identified two risk factors for conversion: ultrasonographic signs of inflammation (adjusted odds ratio [aOR] = 8.5; 95% confidence interval [CI]: 3.3, 21.9) and age > 60 years (aOR = 8.1; 95% CI: 2.9, 22.2) after adjusting for physical signs, alkaline phosphatase and BMI levels.
  
  
  CONCLUSIONS
  Preoperative risk factors evaluated by the present study confirm the likelihood of conversion. Recognition of these factors is important for understanding the characteristics of patients at a higher risk of conversion.
authors.affiliation: Department of Surgery, Aga Khan University, Karachi, Pakistan.
authors.forename: M
authors.initials: M
authors.lastname: Tayeb
authors.forename: S A
authors.initials: SA
authors.lastname: Raza
authors.forename: M R
authors.initials: MR
authors.lastname: Khan
authors.forename: R
authors.initials: R
authors.lastname: Azami
mesh_terms: D000328:Adult; D000367:Age Factors; D016022:Case-Control Studies; D002763:Cholecystectomy / Q000379:methods*; D002764:Cholecystitis / Q000000981:diagnostic imaging; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D012307:Risk Factors; D014463:Ultrasonography