title: Transvaginal endoscopic partial gastrectomy in porcine models: the role of an extra endoscope for gastric control.
abstract: BACKGROUND
  Transvaginal natural orifice translumenal endoscopic surgery (NOTES) gastrectomy is technically challenging, because wide perigastric dissection under appropriate tissue triangulation is unfeasible with current endoscopic instruments alone. The aim of this study was to investigate the feasibility of transvaginal NOTES gastrectomy with the use of an extra endoscope as a retracting device of the stomach.
  
  
  METHODS
  This acute in vivo feasibility study was performed under the approval of the Institutional Animal Care and Use Committee (IACUC). Four female 40-kg pigs received general anesthesia and underwent transvaginal endoscopic partial gastrectomy. Under laparoscopic guidance, the uterus was fixed anteriorly and transvaginal access was established in a standard fashion. The perigastric ligaments were dissected with needle knife/insulation-tipped electrosurgical knife (IT) via transvaginally placed double-channel endoscope. This step was assisted with the second, CO(2)-insufflating endoscope advanced in the stomach (i.e., so-called endoscopic gastric control). A linear stapling device with a flexible shaft was then passed transvaginally, and the anterior gastric wall was partially resected. The specimen was isolated and retrieved through the vagina. Concluding endoscopy was carried out to confirm the absence of mucosal damage due to endoscopic gastric control. This was further confirmed at necropsy immediately after sacrifice.
  
  
  RESULTS
  All animals underwent successful transvaginal NOTES gastrectomy. Endoscopic gastric control greatly facilitated perigastric dissection by providing appropriate tissue countertraction on the ligaments. Use of transabdominal (laparoscopic) graspers was thus minimized. There were no intraoperative complications directly related to use of the primary (transvaginal) endoscope or the additional (gastric) endoscope. Distention of downstream bowel after gastric insufflation was minimal with CO(2). No major injuries were noted on gastric mucosa at postmortem investigations.
  
  
  CONCLUSIONS
  Transvaginal NOTES partial gastrectomy is feasible in porcine models. Use of an extra endoscope to retract the stomach is effective to minimize transabdominal assistance. Further studies on human subjects are necessary to establish this as a safe and attractive ancillary technique in NOTES.
authors.affiliation: Department of Surgery, Osaka University Graduate School of Medicine, Osaka, Japan. knakajima@surg1.med.osaka-u.ac.jp
authors.forename: Kiyokazu
authors.initials: K
authors.lastname: Nakajima
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Takahashi
authors.forename: Yoshihito
authors.initials: Y
authors.lastname: Souma
authors.forename: Shinichiro
authors.initials: S
authors.lastname: Shinzaki
authors.forename: Takuya
authors.initials: T
authors.lastname: Yamada
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Yoshio
authors.forename: Toshirou
authors.initials: T
authors.lastname: Nishida
mesh_terms: D000818:Animals; D019723:Endoscopes; D004724:Endoscopy / Q000379:methods*; D005240:Feasibility Studies; D005260:Female; D005743:Gastrectomy / Q000295:instrumentation / Q000379:methods*; D010535:Laparoscopy; D017792:Surgical Stapling; D034421:Sus scrofa; D014621:Vagina