title: Effects of adjustable gastric bands on gastric emptying, supra- and infraband transit and satiety: a randomized double-blind crossover trial using a new technique of band visualization.
abstract: BACKGROUND
  The laparoscopic adjustable gastric band (LAGB) has previously been classified as a restrictive procedure; physically limiting meal size. Recently, the key mechanism has been hypothesized to be the induction of satiety without restriction. Effects can be controlled by modifying LAGB volume, possibly as a result of effects on gastric emptying or transit through the LAGB.
  
  
  METHODS
  Successful LAGB patients underwent paired, double blinded, esophageal transit and gastric emptying scintigraphic studies; with the LAGB at optimal volume and near empty. A new technique allowed assessment of emptying and transit through the infra- and supraband compartments.
  
  
  RESULTS
  Fourteen of 17 patients completed both scans (six males; mean age, 48.9 ± 11.3 years, % excess weight loss 69.0 ± 15.2). At optimal volume a delay in transit of semi-solids into the infraband compartment was observed in ten patients vs. three when the LAGB was empty, (p = 0.01). The median retention of a meal in the supraband compartment immediately after cessation of intake was: empty 2.8% (2.3-7.9) vs. optimal 3.6% (1.7-4.5), (p = 0.57). Overall gastric emptying half time (minutes) was normal at both volumes: optimal 64.2 ± 29.8 vs. empty 95.2 ± 64.1, (p = 0.14). LAGB volume did not affect satiety before the scan: optimal 4.3 ± 1.9 vs. empty 4.0 ± 2.2, (p = 0.49), or 90 min later: optimal 6.1 ± 1.9 vs. empty 5.9 ± 1.4, (p = 0.68).
  
  
  CONCLUSIONS
  The optimally adjusted LAGB briefly delays semi-solid transit into the infraband stomach without physically restricting meal size. The supraband compartment is usually empty of an ingested meal 1-2 min after intake ceases and overall gastric emptying is not affected.
authors.affiliation: Centre for Obesity Research and Education (CORE), Monash University, The Alfred Hospital, Melbourne, Australia. paul.burton@med.monash.edu.au
authors.forename: Paul Robert
authors.initials: PR
authors.lastname: Burton
authors.forename: Kenneth
authors.initials: K
authors.lastname: Yap
authors.forename: Wendy A
authors.initials: WA
authors.lastname: Brown
authors.forename: Cheryl
authors.initials: C
authors.lastname: Laurie
authors.forename: Matthew
authors.initials: M
authors.lastname: O'Donnell
authors.forename: Geoff
authors.initials: G
authors.lastname: Hebbard
authors.forename: Victor
authors.initials: V
authors.lastname: Kalff
authors.forename: Paul E
authors.initials: PE
authors.lastname: O'Brien
mesh_terms: D000328:Adult; D018592:Cross-Over Studies; D004311:Double-Blind Method; D005260:Female; D005746:Gastric Emptying; D005772:Gastrointestinal Transit; D015391:Gastroplasty / Q000295:instrumentation / Q000706:statistics & numerical data*; D006801:Humans; D010535:Laparoscopy / Q000295:instrumentation / Q000706:statistics & numerical data*; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000000981:diagnostic imaging / Q000601:surgery; D011877:Radionuclide Imaging; D012528:Satiety Response; D016896:Treatment Outcome; D015431:Weight Loss