Sonography for selecting candidates for laparoscopic cholecystectomy: A prospective study

OBJECTIVE. We assessed the value of sonography in predicting intraoperative difficulties far patients undergoing laparoscopic cholecystectomy and in i dentifying indicators for conversion to conventional cholecystectomy. SUBJECTS AND METHODS. Upper abdominal sonography was performed (according t o a checklist) in 75 consecutive patients before laparoscopic cholecystecto my. Sonographic findings were Verified by the surgeon in the operating room . RESULTS. Conversion from laparoscopic surgery to laparotomy was performed i n five patients (6.7%). Of 75 patients, 19 had sonograms revealing gallblad der wall thickening (>4 mm); surgical preparation difficulties in 16 of the se patients led to laparotomy in four patients. Sensitivity, specificity, p ositive predictive value, and accuracy of wall thickening as an indicator o f 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, 2 0.8%; 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 sonogra phy for cholecystolithiasis was 100%. CONCLUSION. On sonography,,gallbladder wall thickening is the most sensitiv e indicator and pericholecystic fluid is the most specific indicator of tec hnical difficulties during laparoscopic cholecystectomy. Such difficulties may require conversion to laparotomy.