title: Safety and efficacy of the submucosal tunnel without mucosal closure for the transgastric approach in a porcine survival model.
abstract: BACKGROUND
  Usefulness of submucosal tunneling for transgastric approach with clip closure of the mucosal incision in natural orifice translumenal endoscopic surgery (NOTES) has been described. Although the narrow longitudinal submucosal tunnel itself is considered good for wound approximation and healing, no reports have evaluated the sealing effect in this technique. This study was aimed at evaluating the technical feasibility of a submucosal tunnel technique for transgastric peritoneal access without mucosal closure.
  
  
  METHODS
  Transgastric peritoneoscopy using submucosal tunneling with endoscopic submucosal dissection without mucosal closure was performed on six 40- to 45-kg female pigs. Measures included (a) evaluation of technical feasibility, (b) clinical monitoring for 7 days, (c) necropsy findings, and (d) pathological examination.
  
  
  RESULTS
  NOTES transgastric peritoneoscopy was successfully performed in all pigs, and all recovered well clinically. Necropsy findings revealed no peritonitis, confirming completeness of gastric closure in 5 of the 6 pigs. One pig in which the submucosal layer of the tunnel was injured during dissection from the muscular layer showed local peritonitis. Pathological examination at the submucosal site tunnel showed wound healing with focal transmural fibrosis and inflammatory cell infiltration in 5 pigs, whereas the pig with peritonitis had a large mucosal defect with necrotic tissue, abscess formation, and focal transmural fibrosis.
  
  
  CONCLUSIONS
  The submucosal tunnel technique without mucosal closure is safe and effective for transgastric peritoneal access and subsequent closure, when the endoscopists' learning curve is accomplished and the submucosal tunnel is produced without damaging of mucosa. It is necessary to use devices such as mucosal clips or tissue anchors in order to achieve adequate healing of mucosal defect.
authors.affiliation: Department of Surgery I, Oita University Faculty of Medicine, 1-1 Idaigaoka, Hasama-machi, Oita 879-5593, Japan. tomakagi@med.oita-u.ac.jp
authors.forename: Tomonori
authors.initials: T
authors.lastname: Akagi
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Yasuda
authors.forename: Youhei
authors.initials: Y
authors.lastname: Kono
authors.forename: Kosuke
authors.initials: K
authors.lastname: Suzuki
authors.forename: Koji
authors.initials: K
authors.lastname: Kawaguchi
authors.forename: Fumitaka
authors.initials: F
authors.lastname: Yoshizumi
authors.forename: Masafumi
authors.initials: M
authors.lastname: Inomata
authors.forename: Norio
authors.initials: N
authors.lastname: Shiraishi
authors.forename: Seigo
authors.initials: S
authors.lastname: Kitano
mesh_terms: D000818:Animals; D005260:Female; D005753:Gastric Mucosa / Q000473:pathology / Q000601:surgery*; D005773:Gastroscopy / Q000009:adverse effects* / Q000379:methods*; D006651:Histocytochemistry; D010535:Laparoscopy / Q000009:adverse effects* / Q000379:methods*; D057605:Natural Orifice Endoscopic Surgery / Q000009:adverse effects* / Q000379:methods*; D013552:Swine; D000267:Tissue Adhesions; D058106:Wound Closure Techniques