[The significance of preoperative and postoperative sonography for biliary tract surgery. A prospective study].

112 patients with biliary calculi and destined for cholecystectomy were sonographically investigated in a prospective study carried immediately before the operation as well as between the third and fifth, and between the seventh and ninth postoperative day. Biliary calculi were sonographically detectable in 111 of the 112 patients (sensitivity 0.99). The sonographically measured bile duct diameter agreed well with the actual bile duct diameter (r = 0.898). There was a correlation between the bile duct diameter and the severity of the underlying biliary disease. A sonographic diagnosis was successful in 11 of 17 patients with choledocholithiasis (sensitivity 0.65) whereas 10 false positive diagnoses gave a specificity of 0.88. Gallbladder wall thickness above 4 mm had a sensitivity of 0.9 and a specificity of 0.72 for the detection of severe chronic or acute cholecystitis. A high rate (50%) of postoperative subhepatic fluid collections was a conspicuous finding but these were predominantly transient or only short-lived and attained clinical significance in only 7 out of 108 patients (6.5%).