title: Repeated mechanical lengthening of intestinal segments in a novel model.
abstract: OBJECTIVE
  Currently, animal models used for mechanical intestinal lengthening utilize a single lengthening procedure prior to analysis or restoration back into continuity. Here we developed a novel surgical model to examine the feasibility of repeated lengthening of intestinal segments.
  
  
  METHODS
  A Roux-en-Y jejunojejunostomy with a blind Roux limb was created in rats. An encapsulated polycaprolactone spring was placed into a 1cm segment of the Roux limb. After 4 weeks, a second encapsulated PCL spring was inserted into a 1cm portion of the lengthened segment. After another 4 weeks, the repeatedly lengthened segments were retrieved for histological analyses.
  
  
  RESULTS
  Jejunal segments of the Roux limb were successfully lengthened from 1.0 cm to 2.6 ± 0.7 cm. Four weeks after the second PCL spring placement, 1.0 cm of the previously lengthened segment increased to 2.7 ± 0.8 cm. Stronger mechanical force was required to achieve subsequent re-lengthening. Lengthened and re-lengthened segments had increased smooth muscle thickness and crypt depth when compared to normal jejunal mucosa.
  
  
  CONCLUSIONS
  Using the Roux-en-Y model, previously lengthened segments of intestine can be successfully re-lengthened. Intestinal segments may be subjected to multiple lengthening procedures to achieve clinically significant length 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: 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: Veronica F
authors.initials: VF
authors.lastname: Sullins
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: Joshua D
authors.initials: JD
authors.lastname: Rouch
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: Division of Pediatric Surgery, Department of Surgery, University of California, Los Angeles, CA, USA.
authors.forename: Elvin
authors.initials: E
authors.lastname: Chiang
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: D000713:Anastomosis, Roux-en-Y; D000714:Anastomosis, Surgical; D000818:Animals; D005260:Female; D007413:Intestinal Mucosa / Q000601:surgery; D007583:Jejunum / Q000601:surgery*; D009130:Muscle, Smooth / Q000601:surgery; D017207:Rats, Sprague-Dawley; D012778:Short Bowel Syndrome / Q000601:surgery; D015626:Tissue Expansion / Q000295:instrumentation* / Q000379:methods*
keywords: Biodegradable lengthening device; Bowel lengthening; Distraction enterogenesis; Mechanical enterogenesis; Short bowel syndrome; Spring lengthening device