title: Use of a magnetic sphincter for the treatment of GERD: a feasibility study.
abstract: BACKGROUND
  The success of fundoplication surgery varies widely; furthermore, complications after fundoplication can be common. We introduced a new device to treat GERD: biomechanical augmentation of the lower esophageal sphincter (LES) by use of a magnetic reinforcing appliance.
  
  
  OBJECTIVE
  The aim was to determine whether a magnetic appliance could safely increase LES pressure, maintain a closed sphincter except during swallowing and belching, and increase the gastric yield pressure in a porcine model.
  
  
  METHODS
  Ex vivo work-assessed design variables that would augment the reflux barrier yet still preserve swallow function. Porcine acute and chronic (44 weeks) postimplant studies were also performed. A single animal underwent planned device removal.
  
  
  METHODS
  Gastric yield pressure, animal behavior, endoscopy, barium studies, balloon expansion studies, esophageal manometry, and histology.
  
  
  RESULTS
  Gastric yield pressure correlated with increasing magnetic forces (R(2)=0.5608, P< .001). The sphincter augmentation device was safe in all animals, with no observed effect on eating behavior and normal weight gain. The mucosa of the esophagus appeared normal at all intervals, and there was no device migration or significant tissue inflammation. The average LES pressure rose after implantation (P< .005). Balloon and barium studies demonstrated a closed sphincter with normal opening of the gastroesophageal junction during swallowing.
  
  
  CONCLUSIONS
  Magnetic sphincter augmentation is a novel approach for the treatment of GERD. This study demonstrates the safety and feasibility of such a device in a porcine model. Further investigation of this device for the treatment of GERD in humans seems warranted.
authors.affiliation: Minnesota Gastroenterology, Plymouth, Minnesota 55446, USA.
authors.forename: Robert A
authors.initials: RA
authors.lastname: Ganz
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Gostout
authors.forename: Jerry
authors.initials: J
authors.lastname: Grudem
authors.forename: William
authors.initials: W
authors.lastname: Swanson
authors.forename: Todd
authors.initials: T
authors.lastname: Berg
authors.forename: Tom R
authors.initials: TR
authors.lastname: DeMeester
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D004867:Equipment Design; D049630:Esophageal Sphincter, Lower; D005240:Feasibility Studies; D005764:Gastroesophageal Reflux / Q000601:surgery*; D008280:Magnetics; D008297:Male; D011312:Pressure; D019736:Prostheses and Implants; D013552:Swine