title: Preoperative abdominal ultrasound may be misleading in risk stratification for presence of common bile duct abnormalities.
abstract: BACKGROUND
  Following the advent of laparoscopic cholecystectomy (LC), the preoperative predictors of common bile duct (CBD) abnormalities became more important in perioperative decision making. Preoperative transabdominal ultrasound (US) is used to assess the preoperative risks associated with CBD abnormalities. This study attempts to determine the sensitivity and specificity of US in determining CBD abnormalities in patients prior to LC.
  
  
  METHODS
  US measurements of the CBD diameter and presence of stones were ascertained from radiology reports in 100 patients who had LC with a routine intraoperative cholangiogram (IOC). The same information was obtained from the patients' IOC. A supraduodenal CBD diameter of >8 mm was considered dilated.
  
  
  RESULTS
  US demonstrated a sensitivity of 25% and a specificity of 70% for the detection of CBD dilatation compared to IOC. The sensitivity of US for predicting CBD dilatation was 55% when the IOC-derived diameter was >10 mm and 100% when it was >15 mm. The overall sensitivity of US for detection of stones was 10%; it improved to 17% in patients with a dilated CBD on US.
  
  
  CONCLUSIONS
  Preoperative ultrasound is neither sensitive nor specific for detecting CBD dilatation or presence of stones. A negative preoperative US report may be misleading in risk stratification for the presence of these CBD abnormalities. In order to avoid missing any CBD pathology, we recommend the routine use of intraoperative cholangiography.
authors.affiliation: Department of Surgery, Bellevue Hospital Center, New York University School of Medicine, New York 10016, USA.
authors.forename: R A
authors.initials: RA
authors.lastname: Lichtenbaum
authors.forename: H F
authors.initials: HF
authors.lastname: McMullen
authors.forename: R M
authors.initials: RM
authors.lastname: Newman
mesh_terms: D002758:Cholangiography; D017081:Cholecystectomy, Laparoscopic; D003135:Common Bile Duct / Q000002:abnormalities* / Q000000981:diagnostic imaging / Q000601:surgery; D003937:Diagnosis, Differential; D004108:Dilatation, Pathologic / Q000000981:diagnostic imaging / Q000601:surgery; D042882:Gallstones / Q000000981:diagnostic imaging* / Q000601:surgery; D006801:Humans; D016343:Monitoring, Intraoperative / Q000379:methods; D011237:Predictive Value of Tests; D011300:Preoperative Care / Q000379:methods*; D018570:Risk Assessment; D014463:Ultrasonography