title: Sonography for selecting candidates for laparoscopic cholecystectomy: a prospective study.
abstract: OBJECTIVE
  We assessed the value of sonography in predicting intraoperative difficulties for patients undergoing laparoscopic cholecystectomy and in identifying indicators for conversion to conventional cholecystectomy.
  
  
  METHODS
  Upper abdominal sonography was performed (according to a checklist) in 75 consecutive patients before laparoscopic cholecystectomy. Sonographic findings were verified by the surgeon in the operating room.
  
  
  RESULTS
  Conversion from laparoscopic surgery to laparotomy was performed in five patients (6.7%). Of 75 patients, 19 had sonograms revealing gallbladder wall thickening (>4 mm); surgical preparation difficulties in 16 of these patients led to laparotomy in four patients. Sensitivity, specificity, positive predictive value, and accuracy of wall thickening as an indicator of technical difficulties were 66.7%, 94.1%, 84.2%, and 85.3%, respectively. Sensitivity, specificity, positive predictive value, and accuracy of wall thickening as an indicator of surgical conversion were 80.0%, 78.6%, 21.1%, and 78.7%, respectively. Technical difficulties at laparoscopy occurred in all five patients with pericholecystic fluid on sonography (sensitivity, 20.8%; specificity, 100%; positive predictive value, 100%; accuracy, 74.7%) and led to laparotomy in three patients (sensitivity 60.0%, specificity 97.1%, positive predictive value 60%, accuracy 94.7%). The accuracy of sonography for cholecystolithiasis was 100%.
  
  
  CONCLUSIONS
  On sonography, gallbladder wall thickening is the most sensitive indicator and pericholecystic fluid is the most specific indicator of technical difficulties during laparoscopic cholecystectomy. Such difficulties may require conversion to laparotomy.
authors.affiliation: Department of Diagnostic Radiology, University of Würzburg, Germany.
authors.forename: H P
authors.initials: HP
authors.lastname: Dinkel
authors.forename: S
authors.initials: S
authors.lastname: Kraus
authors.forename: J
authors.initials: J
authors.lastname: Heimbucher
authors.forename: R
authors.initials: R
authors.lastname: Moll
authors.forename: J
authors.initials: J
authors.lastname: Knüpffer
authors.forename: H J
authors.initials: HJ
authors.lastname: Gassel
authors.forename: S M
authors.initials: SM
authors.lastname: Freys
authors.forename: K H
authors.initials: KH
authors.lastname: Fuchs
authors.forename: G
authors.initials: G
authors.lastname: Schindler
mesh_terms: D000005:Abdomen / Q000000981:diagnostic imaging*; D000328:Adult; D000368:Aged; D017081:Cholecystectomy, Laparoscopic; D002769:Cholelithiasis / Q000000981:diagnostic imaging / Q000601:surgery; D005260:Female; D006801:Humans; D007431:Intraoperative Complications; D008297:Male; D008875:Middle Aged; D018579:Patient Selection; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D014463:Ultrasonography