title: The common duct dilates after cholecystectomy and with advancing age: reality or myth?
abstract: OBJECTIVE
  To evaluate changes in the common duct diameter on sonography over time in patients with and without cholecystectomy.
  
  
  METHODS
  We retrospectively evaluated the common duct diameter, central biliary dilatation, and interval change in 1079 patients who underwent sonography at least 2 years apart over a 6-year period. A board-certified radiologist, blinded to clinical and laboratory data, measured the duct diameter. A total of 893 patients (568 female and 325 male) were divided into 3 groups: group 1, remote cholecystectomy before sonography (mean, 9.7 years before sonography; n = 117); group 2, interval cholecystectomy between the first and second sonographic examinations (n = 56); and group 3, no cholecystectomy (n = 720). All groups were stratified by age, and group 3 was also stratified by the absence (n = 528) or presence (n=192) of gallstones.
  
  
  RESULTS
  Duct diameters at baseline and follow-up averaged 4.5 and 5.2, 3.6 and 4.9, and 3.5 and 3.9 mm in groups 1, 2, and 3, respectively. Group 1 ducts were larger at baseline than in the other groups (P < .001). At follow-up, group 2 ducts showed a greater interval diameter increase than the other groups (P < .001). In a subanalysis of each group based on age, there was a mild increase in duct size with increasing age, although not clinically significant and within normal limits. In group 3 patients who never had gallstones, there was a significant small increase in duct size over decades (P < .001). The baseline duct sizes for patients with gallstones were not significantly different from those who never had gallstones (P = .15).
  
  
  CONCLUSIONS
  Patients with remote cholecystectomy have larger common duct diameters than those with no or interval cholecystectomy. Most asymptomatic patients with or without cholecystectomy have a normal common duct diameter.
authors.affiliation: Department of Diagnostic Radiology, University of Alabama at Birmingham, 619 19th St S, JTN 338, Birmingham, AL 35249-6830 USA. tmcarthur@uabmc.edu.
authors.forename: Tatum A
authors.initials: TA
authors.lastname: McArthur
authors.forename: Virginia
authors.initials: V
authors.lastname: Planz
authors.forename: Naomi S
authors.initials: NS
authors.lastname: Fineberg
authors.forename: Franklin N
authors.initials: FN
authors.lastname: Tessler
authors.forename: Michelle L
authors.initials: ML
authors.lastname: Robbin
authors.forename: Mark E
authors.initials: ME
authors.lastname: Lockhart
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000407:Alabama / Q000453:epidemiology; D002763:Cholecystectomy / Q000706:statistics & numerical data*; D003135:Common Bile Duct / Q000000981:diagnostic imaging* / Q000473:pathology; D003137:Common Bile Duct Diseases / Q000000981:diagnostic imaging* / Q000453:epidemiology*; D004108:Dilatation, Pathologic; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000000981:diagnostic imaging* / Q000453:epidemiology*; D015995:Prevalence; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012307:Risk Factors; D012680:Sensitivity and Specificity; D016037:Single-Blind Method; D016896:Treatment Outcome; D014463:Ultrasonography / Q000706:statistics & numerical data*; D055815:Young Adult
keywords: aging; cholecystectomy; cholelithiasis; common duct