title: Lower esophageal sphincter augmentation by endoscopic injection of dextranomer hyaluronic acid copolymer in a porcine gastroesophageal reflux disease model.
abstract: BACKGROUND
  We previously demonstrated feasibility, safety, and a reproducible histologic bulking effect after injection of dextranomer hyaluronic acid copolymer (DxHA) into the gastroesophageal junction of rabbits. In the current study, we investigated the potential for DxHA to augment the lower esophageal sphincter (LES) in a porcine model of gastroesophageal reflux disease (GERD).
  
  
  METHODS
  Twelve Yucatan miniature pigs underwent LES manometry and 24-hour ambulatory pH monitoring at baseline, after cardiomyectomy, and 6weeks after randomization to endoscopic injection of either DxHA or saline at the LES. After necropsy, the foregut, including injection sites, was histologically examined.
  
  
  RESULTS
  Pigs in both groups had similar weight progression. Cardiomyectomy induced GERD in all animals, as measured by a rise in the median % of time pH <5 from 0.6 to 11.6 (p=0.02). Endoscopic injection of DxHA resulted in a higher median difference in LES length (1.8cm vs. 0.4cm, p=0.03). In comparison with saline injection, DxHA resulted in 120% increase in LES pressure, and 76% decrease in the mean duration of reflux episodes, but these results were not statistically significant. Injection of DxHA induced a foreign body reaction with fibroblasts and giant cells.
  
  
  CONCLUSIONS
  Porcine cardiomyectomy is a reproducible animal GERD model. Injection of DxHA may augment the LES, offering a potential therapeutic effect in GERD.
authors.affiliation: Division of Pediatric General and Thoracic Surgery, The Montreal Children's Hospital, McGill University Health Centre, Montreal, Quebec, Canada.
authors.forename: Abdullah
authors.initials: A
authors.lastname: Alshehri
authors.affiliation: Division of Pediatric General and Thoracic Surgery, The Montreal Children's Hospital, McGill University Health Centre, Montreal, Quebec, Canada. Electronic address: Sherif.Emil@McGill.ca.
authors.forename: Sherif
authors.initials: S
authors.lastname: Emil
authors.affiliation: Division of Pediatric General and Thoracic Surgery, The Montreal Children's Hospital, McGill University Health Centre, Montreal, Quebec, Canada.
authors.forename: Jean-Martin
authors.initials: JM
authors.lastname: Laberge
authors.affiliation: Division of Pediatric General and Thoracic Surgery, The Montreal Children's Hospital, McGill University Health Centre, Montreal, Quebec, Canada.
authors.forename: Sherif
authors.initials: S
authors.lastname: Elkady
authors.affiliation: Division of Pediatric Pathology, The Montreal Children's Hospital, McGill University Health Centre, Montreal, Quebec, Canada.
authors.forename: Miriam
authors.initials: M
authors.lastname: Blumenkrantz
authors.affiliation: Division of Gastroenterology, The Montreal General Hospital, McGill University Health Centre, Montreal, Quebec, Canada.
authors.forename: Serge
authors.initials: S
authors.lastname: Mayrand
authors.affiliation: Division of Pediatric Gastroenterology, The Montreal Children's Hospital, McGill University Health Centre, Montreal, Quebec, Canada.
authors.forename: Veronique
authors.initials: V
authors.lastname: Morinville
authors.affiliation: Division of Pediatric Pathology, The Montreal Children's Hospital, McGill University Health Centre, Montreal, Quebec, Canada.
authors.forename: Van-Hung
authors.initials: VH
authors.lastname: Nguyen
mesh_terms: D000818:Animals; D003911:Dextrans / Q000008:administration & dosage*; D004195:Disease Models, Animal; D049630:Esophageal Sphincter, Lower / Q000187:drug effects* / Q000473:pathology / Q000502:physiology; D050782:Esophageal pH Monitoring; D004945:Esophagoscopy; D005549:Foreign-Body Reaction / Q000503:physiopathology; D005764:Gastroesophageal Reflux / Q000473:pathology / Q000503:physiopathology / Q000628:therapy*; D006820:Hyaluronic Acid / Q000008:administration & dosage*; D008365:Manometry; D010865:Pilot Projects; D013552:Swine
chemical_list: D003911:Dextrans; C487487:dextranomer-hyaluronic acid copolymer; D006820:Hyaluronic Acid
keywords: Augmentation; Deflux®; GERD; Lower esophageal sphincter