title: Endoscopic suture fixation of self-expanding metallic stents with and without submucosal injection.
abstract: BACKGROUND
  Self-expanding metallic stents (SEMS) are useful for treating leaks after bariatric procedures but stent migration (12 to 40 %) remains a problem. Suture fixation has been used to minimize migration but has attendant risks of transmural penetration. We hypothesized that submucosal injection would decrease the risk of full thickness suture penetration while still providing greater pullout forces than endoscopic clipping.
  
  
  METHODS
  Porcine explant models and 155 mm SEMS were used with a force meter to measure the pullout forces required to dislodge the stent. Stents were first deployed without fixation and this pullout force acted as a control. The explants were then randomized to receive fixation with clips, endoscopic suturing with submucosal elevation, or endoscopic suturing without submucosal elevation. The pullout force was again measured and the ratio of the experimental to control pullout forces was used as a measure of the efficacy of the fixation.
  
  
  RESULTS
  Endoscopic suture fixation after submucosal injection resulted in statistically significant increased pullout force compared to clip fixation (n = 5; mean force ratio 462 %; 95 % confidence interval [CI] 281-643 %; p < 0.01). Endoscopic suturing fixation without submucosal injection also resulted in statistically significant increased pullout force (n = 5; mean force ratio 765 %; 95 % CI 258-632 %; p < 0.01). Fixation with clips did not result in significantly increased pullout force compared to no fixation (n = 5; mean force ratio 108 %; 95 % CI 56-159 %; p < 0.01). Submucosal injection also eliminated full thickness suture penetration (0/10 submucosal injection; 7/10 no injection).
  
  
  CONCLUSIONS
  Endoscopic suture fixation of SEMS resulted in a statistically significant increase in pullout force necessary to displace the stents. Submucosal injection prior to suture fixation preserves the increased pullout force while minimizing the risk of transmural penetration with the potential for less risk of injury to mediastinal structures.
authors.affiliation: Department of Surgery, The Methodist Hospital, 6550 Fannin Street, Suite 1661, Houston, TX, 77030, USA, vwilcox2000@gmail.com.
authors.forename: Victor T
authors.initials: VT
authors.lastname: Wilcox
authors.forename: Albert Y
authors.initials: AY
authors.lastname: Huang
authors.forename: Nabil
authors.initials: N
authors.lastname: Tariq
authors.forename: Brian J
authors.initials: BJ
authors.lastname: Dunkin
mesh_terms: D057868:Anastomotic Leak / Q000601:surgery*; D000818:Animals; D004195:Disease Models, Animal; D016099:Endoscopy, Gastrointestinal / Q000009:adverse effects / Q000379:methods*; D004947:Esophagus / Q000601:surgery; D005260:Female; D005753:Gastric Mucosa / Q000601:surgery*; D015607:Stents; D013270:Stomach / Q000601:surgery; D013536:Suture Techniques; D013552:Swine