title: Effects of omega-loop bypass on esophagogastric junction function.
abstract: BACKGROUND
  At present, no objective data are available on the effect of omega-loop gastric bypass (OGB) on gastroesophageal junction and reflux.
  
  
  OBJECTIVE
  To evaluate the possible effects of OGB on esophageal motor function and a possible increase in gastroesophageal reflux.
  
  
  METHODS
  University Hospital, Italy; Public Hospital, Italy.
  
  
  METHODS
  Patients underwent clinical assessment for reflux symptoms, and endoscopy plus high-resolution impedance manometry (HRiM) and 24-hour pH-impedance monitoring (MII-pH) before and 1 year after OGB. A group of obese patients who underwent sleeve gastrectomy (SG) were included as the control population.
  
  
  RESULTS
  Fifteen OGB patients were included in the study. After surgery, none of the patients reported de novo heartburn or regurgitation. At endoscopic follow-up 1 year after surgery, esophagitis was absent in all patients and no biliary gastritis or presence of bile was recorded. Manometric features and patterns did not vary significantly after surgery, whereas intragastric pressures (IGP) and gastroesophageal pressure gradient (GEPG) statistically diminished (from a median of 15 to 9.5, P<.01, and from 10.3 to 6.4, P<.01, respectively) after OGB. In contrast, SG induced a significant elevation in both parameters (from a median of 14.8 to 18.8, P<.01, and from 10.1 to 13.1, P<.01, respectively). A dramatic decrease in the number of reflux events (from a median of 41 to 7; P<.01) was observed after OGB, whereas in patients who underwent SG a significant increase in esophageal acid exposure and number of reflux episodes (from a median of 33 to 53; P<.01) was noted.
  
  
  CONCLUSIONS
  In contrast to SG, OGB did not compromise the gastroesophageal junction function and did not increase gastroesophageal reflux, which was explained by the lack of increased IGP and in GEPG as assessed by HRiM.
authors.affiliation: Division of General and Bariatric Surgery, Department of Surgery, Second University of Naples, Naples, Italy. Electronic address: salvatore.tolone@unina2.it.
authors.forename: Salvatore
authors.initials: S
authors.lastname: Tolone
authors.affiliation: General and Bariatric Surgery Unit, Camilliani Hospital, Casoria, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Cristiano
authors.affiliation: Gastroenterology Unit, Department of Surgery, Oncology and Gastroenterology, University of Padua, Padua, Italy.
authors.forename: Edoardo
authors.initials: E
authors.lastname: Savarino
authors.affiliation: General and Bariatric Surgery Unit, Camilliani Hospital, Casoria, Italy.
authors.forename: Francesco Saverio
authors.initials: FS
authors.lastname: Lucido
authors.affiliation: General and Bariatric Surgery Unit, Camilliani Hospital, Casoria, Italy.
authors.forename: Domenico Ivan
authors.initials: DI
authors.lastname: Fico
authors.affiliation: Division of General and Bariatric Surgery, Department of Surgery, Second University of Naples, Naples, Italy.
authors.forename: Ludovico
authors.initials: L
authors.lastname: Docimo
mesh_terms: D000328:Adult; D017097:Electric Impedance; D004943:Esophagogastric Junction / Q000503:physiopathology*; D005260:Female; D005500:Follow-Up Studies; D015390:Gastric Bypass / Q000379:methods*; D005764:Gastroesophageal Reflux / Q000453:epidemiology / Q000517:prevention & control*; D006801:Humans; D007558:Italy / Q000453:epidemiology; D008297:Male; D008365:Manometry; D009767:Obesity, Morbid / Q000503:physiopathology / Q000601:surgery*; D011312:Pressure; D012189:Retrospective Studies; D016896:Treatment Outcome
keywords: Bariatric surgery; GERD; High-resolution manometry; Impedance; MII-pH; Obesity; Omega-loop gastric bypass; One-anastomosis gastric bypass; Reflux