title: Early changes in postprandial gallbladder emptying in morbidly obese patients undergoing Roux-en-Y gastric bypass: correlation with the occurrence of biliary sludge and gallstones.
abstract: BACKGROUND
  Gallstones have been frequently diagnosed after Roux-en-Y gastric bypass (RYGBP). Gallbladder stasis associated with duodenal exclusion may play a role in their pathogenesis.
  
  
  METHODS
  Gallbladder emptying was studied before and on the 30th and 31st postoperative days (POD) after RYGBP in 20 morbidly obese patients. Gallbladder volume after fasting and every 15 min during a 2-h period following administration of a standard liquid meal was determined by sonography. On the 31st POD, the meal was administered through the gastrostomy in order to promote its transit through the duodenum. Fasting volume (FV), maximum ejection fraction (Max EF), and residual volume (RV) were determined. Biliary sludge and calculi were investigated after 1 and 6 months, respectively.
  
  
  RESULTS
  FV was 39.4 +/- 20.2 ml, 50.1 +/- 22.7 ml, and 47.9 +/- 23.4 ml, respectively, for the preoperative and two postoperative assessments (P = 0.09). RV was 7.6 +/- 8.7 ml, 25.1 +/- 20.0 ml, and 24.6 +/- 20.9 ml; and Max EF was 80.5 +/- 20.9%, 54.3 +/- 21.4%, and 50.5 +/- 29.0%, respectively, for the pre-, postoral, and postgastrostomy infusion measurements. There was only a significant difference between the preoperative value and the two postoperative values (P < 0.001). Biliary sludge was detected in 65% of the patients and 46% of them subsequently developed gallstones.
  
  
  CONCLUSIONS
  Gallbladder emptying became significantly compromised after RYGBP. This impairment was unrelated to duodenal exclusion but it was associated with biliary sludge and stone formation.
authors.affiliation: Department of Surgery, Federal University of São Paulo, São Paulo, Brazil. bastoulymichel@hotmail.com
authors.forename: Michel
authors.initials: M
authors.lastname: Bastouly
authors.forename: Carlos Haruo
authors.initials: CH
authors.lastname: Arasaki
authors.forename: Jael Brasil
authors.initials: JB
authors.lastname: Ferreira
authors.forename: Arnaldo
authors.initials: A
authors.lastname: Zanoto
authors.forename: Fabíola Gouveia H P
authors.initials: FG
authors.lastname: Borges
authors.forename: José Carlos
authors.initials: JC
authors.lastname: Del Grande
mesh_terms: D000328:Adult; D001646:Bile; D015992:Body Mass Index; D005260:Female; D005500:Follow-Up Studies; D016473:Gallbladder Emptying / Q000502:physiology*; D042882:Gallstones / Q000000981:diagnostic imaging / Q000209:etiology*; D015390:Gastric Bypass / Q000009:adverse effects*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009767:Obesity, Morbid / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000601:surgery*; D019518:Postprandial Period; D013997:Time Factors; D016896:Treatment Outcome; D014463:Ultrasonography