title: Wireless pH-metry at the gastrojejunostomy after Roux-en-Y gastric bypass: a novel use of the BRAVO™ system.
abstract: BACKGROUND
  The number of gastric bypass operations being performed is increasing rapidly due to good weight loss and alleviation of comorbidities in combination with low mortality and morbidity. Stomal ulcers are, however, a clinical problem after gastric bypass, giving patients discomfort, risk of bleeding, or even perforation. To measure the acidity in the proximal jejunum, we adopted the wireless pH-metry (BRAVO™ system) developed for evaluating reflux esophagitis.
  
  
  METHODS
  Twenty-five patients (4 men; median age, 44 years; body mass index, 29.3) who had undergone Roux-en-Y gastric bypass (RYGBP) 4 years earlier were recruited. Twenty-one asymptomatic, non-proton pump inhibitor (PPI) users, and in addition, four symptomatic patients (ongoing or stopped PPI treatment) were studied. The wireless BRAVO™ capsule was positioned at the level of the gastrojejunal anastomosis under visual control with the endoscope. pH was registered for up to 48 h. Time with pH<4 was calculated. Two patients were studied with two capsules.
  
  
  RESULTS
  Of the 25 recruited patients, capsule placement was successful in all but two patients, and in three patients a constant neutral environment was seen before a premature loss of signal, indicating early loss of position. Thus, 20 successful measurements were made. The mean time of registration was 25.7 (range, 6.1-47.4) h (n=20). In the 16 asymptomatic patients, median percentage of time with pH<4 at the gastrojejunostomy was 10.5% (range, 0.4-37.7%). When dividing the registration time in day (06.00-22.00) and night (22.00-06.00), the median percentage of time with pH<4 was 8.4 and 6.3, respectively (p=0.08). The two double measurements gave similar results indicating consistency. No complications occurred.
  
  
  CONCLUSIONS
  Wireless pH measurements in the proximal jejunum after gastric bypass are feasible and safe. The acidity was significant (10.5% of the registration time) even in asymptomatic patients with small gastric pouches. The described method could be useful in evaluation of epigastralgia after gastric bypass and in appraisal of PPI treatment of stomal ulcer.
authors.affiliation: Department of Surgical Sciences, Uppsala University, S-751 85, Uppsala, Sweden. jakob.hedberg@surgsci.uu.se
authors.forename: Jakob
authors.initials: J
authors.lastname: Hedberg
authors.forename: Hans
authors.initials: H
authors.lastname: Hedenström
authors.forename: Magnus
authors.initials: M
authors.lastname: Sundbom
mesh_terms: D000328:Adult; D000713:Anastomosis, Roux-en-Y; D016022:Case-Control Studies; D050782:Esophageal pH Monitoring / Q000295:instrumentation*; D005260:Female; D015390:Gastric Bypass; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D009767:Obesity, Morbid / Q000601:surgery*; D015203:Reproducibility of Results; D018709:Statistics, Nonparametric; D016896:Treatment Outcome