title: A new in vivo method for testing closures of gastric NOTES incisions using leak of the closure or gastric yield as endpoints.
abstract: BACKGROUND
  We developed a non-survival in vivo model for testing of gastric natural orifice translumenal endoscopic surgery (NOTES) closures based on the gastric yield pressure. The aim of this study was to test our model comparing different endoscopic closure techniques with surgical closure of a NOTES gastric incision.
  
  
  METHODS
  Laparotomy was performed in 30 pigs. One tube for air inflation and one manometry tube were inserted into the stomach via the pylorus, which was closed gas-tight, and the abdominal wall was closed. The stomach was inflated with air, and the gastroesophageal yield pressure was measured. A gastroscopy was performed, and a standard NOTES access was created followed by randomization to closure by surgical suturing, T-tags, Padlock-G over-the-scope (OTS)-clips, OVESCO OTS-clips, and traditional clips. All closures were tested twice with air insufflation. Gastric yield pressure or leak pressure of each closure was recorded.
  
  
  RESULTS
  The mean baseline gastric yield pressure was 80.5 mm Hg. Post-closure yield pressure was 79.9 mm Hg. Leak test results after closure were as follows: surgery, 0/6 leaked; T-tags, 1/6 leaked before reaching yield pressure (56 mm Hg); Padlock-G, 2/5 leaked (71.5 mm Hg); OVESCO OTS-clips, 3/6 leaked (27.2 mm Hg); and traditional clips, 5/6 leaked (27.2 mm Hg). TAS T-tags and surgical closures leaked significantly less than the other groups (P=.01). Traditional clips and OVESCO OTS-clips leaked at significantly lower pressures than the other three groups (P=.007).
  
  
  CONCLUSIONS
  This in vivo model using leak of the closure or the gastric yield pressure as endpoints for testing of the closure strength of a NOTES gastric access site seems to be reproducible. Our results support closure with T-tags and Padlock-G-clips over OVESCO OTS-clips and standard endoscopic clips.
authors.affiliation: Department of Surgery, Sahlgrenska University Hospital, Gothenburg, Sweden.
authors.forename: Asghar
authors.initials: A
authors.lastname: Azadani
authors.forename: Maria
authors.initials: M
authors.lastname: Bergström
authors.forename: Juan
authors.initials: J
authors.lastname: Dot
authors.forename: Monder
authors.initials: M
authors.lastname: Abu-Suboh-Abadia
authors.forename: José Ramón
authors.initials: JR
authors.lastname: Armengol-Miró
authors.forename: Per-Ola
authors.initials: PO
authors.lastname: Park
mesh_terms: D058107:Abdominal Wound Closure Techniques / Q000706:statistics & numerical data; D057868:Anastomotic Leak / Q000453:epidemiology*; D000818:Animals; D005773:Gastroscopy; D057605:Natural Orifice Endoscopic Surgery / Q000379:methods; D011312:Pressure; D013552:Swine