title: Gastric bypass: why Roux-en-Y? A review of experimental data.
abstract: OBJECTIVE
  To highlight the clinical and experimental rationales that support why the Roux-en-Y limb is an important surgical principle for bariatric gastric bypass.
  
  
  METHODS
  We reviewed PubMed citations for open Roux-en-Y gastric bypass (RYGBP), laparoscopic RYGBP, loop gastric bypass, chronic alkaline reflux gastritis, and duodenoesophageal reflux.
  
  
  METHODS
  We reviewed clinical and experimental articles. Clinical articles included prospective, retrospective, and case series of patients undergoing RYGBP, laparoscopic RYGBP, or loop gastric bypass. Experimental articles that were reviewed included in vivo and in vitro models of chronic duodenoesophageal reflux and its effect on carcinogenesis.
  
  
  METHODS
  No formal data extraction was performed. We reviewed published operative times, lengths of stay, and anastomotic leak rates for laparoscopic RYGBP and loop gastric bypass. For in vivo and in vitro experimental models of duodenoesophageal reflux, we reviewed the kinetics and potential molecular mechanisms of carcinogenesis.
  
  
  CONCLUSIONS
  Recent data suggest that laparoscopic loop gastric bypass, performed without the creation of a Roux-en-Y gastroenterostomy, is a faster surgical technique that confers similarly robust weight loss compared with RYGBP or laparoscopic RYGBP. In the absence of a Roux limb, the long-term effects of chronic alkaline reflux are unknown. Animal models and in vitro analyses of chronic alkaline reflux suggest a carcinogenic effect.
authors.affiliation: Department of Surgery, Johns Hopkins Bayview Medical Center, 4940 Eastern Ave, A Building, Room 5C, Baltimore, MD 21224, USA.
authors.forename: Brendan J
authors.initials: BJ
authors.lastname: Collins
authors.forename: Tomoharu
authors.initials: T
authors.lastname: Miyashita
authors.forename: Michael
authors.initials: M
authors.lastname: Schweitzer
authors.forename: Thomas
authors.initials: T
authors.lastname: Magnuson
authors.forename: John W
authors.initials: JW
authors.lastname: Harmon
mesh_terms: D000713:Anastomosis, Roux-en-Y / Q000009:adverse effects*; D000818:Animals; D015390:Gastric Bypass / Q000009:adverse effects / Q000379:methods*; D005756:Gastritis / Q000209:etiology; D005764:Gastroesophageal Reflux / Q000209:etiology; D006801:Humans; D010535:Laparoscopy; D009767:Obesity, Morbid / Q000601:surgery*