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.
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.
Bastouly
Michel
M
Department of Surgery, Federal University of São Paulo, São Paulo, Brazil. bastoulymichel@hotmail.com
Arasaki
Carlos Haruo
CH
Ferreira
Jael Brasil
JB
Zanoto
Arnaldo
A
Borges
Fabíola Gouveia H P
FG
Del Grande
José Carlos
JC
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