title: Intestinal lengthening in an innovative rodent surgical model.
abstract: OBJECTIVE
  Current animal models of mechanical lengthening separate intestinal segments from enteric continuity. Such models are difficult to use for repeated lengthening procedures and result in intestinal tissue loss during restoration into continuity. We sought to create a novel surgical model to allow multiple lengthening procedures for the purpose of maximizing the net increase in tissue after intestinal lengthening.
  
  
  METHODS
  A Roux-en-y jejunojejunostomy with a 6-cm blind-ended Roux limb was created in the proximal jejunum of rats. Encapsulated 1-cm polycaprolactone springs were placed into the closed end of the roux limb and secured with a vessel loop. After 4weeks, lengthened segments and normal jejunum were retrieved for histologic analysis.
  
  
  RESULTS
  Jejunal segments were lengthened from 1.0cm to 3.0cm. Lengthened segments had increased smooth muscle thickness, fewer submucosal ganglia, and similar numbers of myenteric ganglia compared to normal intestine. When compared to normal jejunal mucosa, lengthened segments demonstrated unchanged villus height and increased crypt depth.
  
  
  CONCLUSIONS
  We created an innovative surgical model for intestinal lengthening and successfully lengthened jejunal segments with a degradable spring. The Roux-en-y model may allow the use of a degradable spring for the treatment of short bowel syndrome.
authors.affiliation: Division of Pediatric Surgery, Department of Surgery, University of California, Los Angeles, CA, USA.
authors.forename: Veronica F
authors.initials: VF
authors.lastname: Sullins
authors.affiliation: Division of Pediatric Surgery, Department of Surgery, University of California, Los Angeles, CA, USA.
authors.forename: Andrew
authors.initials: A
authors.lastname: Scott
authors.affiliation: Division of Pediatric Surgery, Department of Surgery, University of California, Los Angeles, CA, USA.
authors.forename: Justin P
authors.initials: JP
authors.lastname: Wagner
authors.affiliation: Department of Bioengineering, University of California, Los Angeles, CA, USA.
authors.forename: Doug
authors.initials: D
authors.lastname: Steinberger
authors.affiliation: Division of Pediatric Surgery, Department of Surgery, University of California, Los Angeles, CA, USA.
authors.forename: Steven L
authors.initials: SL
authors.lastname: Lee
authors.affiliation: Department of Bioengineering, University of California, Los Angeles, CA, USA.
authors.forename: Benjamin M
authors.initials: BM
authors.lastname: Wu
authors.affiliation: Division of Pediatric Surgery, Department of Surgery, University of California, Los Angeles, CA, USA; Department of Bioengineering, University of California, Los Angeles, CA, USA. Electronic address: jdunn@mednet.ucla.edu.
authors.forename: James C Y
authors.initials: JC
authors.lastname: Dunn
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D005260:Female; D007583:Jejunum / Q000601:surgery*; D009130:Muscle, Smooth / Q000601:surgery; D051381:Rats; D017207:Rats, Sprague-Dawley; D012778:Short Bowel Syndrome / Q000601:surgery*; D015626:Tissue Expansion / Q000379:methods*
keywords: Biodegradable lengthening device; Bowel lengthening; Distraction enterogenesis; Mechanical enterogenesis; Short bowel syndrome; Spring lengthening device