Scalability of an endoluminal spring for distraction enterogenesis.
BACKGROUND
Techniques of distraction enterogenesis have been explored to provide increased intestinal length to treat short bowel syndrome (SBS). Self-expanding, polycaprolactone (PCL) springs have been shown to lengthen bowel in small animal models. Their feasibility in larger animal models is a critical step before clinical use.


METHODS
Juvenile mini-Yucatan pigs underwent jejunal isolation or blind ending Roux-en-y jejunojejunostomy with insertion of either a PCL spring or a sham PCL tube. Extrapolated from our spring characteristics in rodents, proportional increases in spring constant and size were made for porcine intestine.


RESULTS
Jejunal segments with 7mm springs with k between 9 and 15N/m demonstrated significantly increased lengthening in isolated segment and Roux-en-y models. Complications were noted in only two animals, both using high spring constant k>17N/m. Histologically, lengthened segments in the isolated and Roux models demonstrated significantly increased muscularis thickness and crypt depth. Restoration of lengthened, isolated segments back into continuity was technically feasible after 6weeks.


CONCLUSIONS
Self-expanding, endoluminal PCL springs, which exert up to 0.6N force, safely achieve significant intestinal lengthening in a translatable, large-animal model. These spring characteristics may provide a scalable model for the treatment of SBS in children.
Department of Surgery, Division of Pediatric Surgery, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, 90095, USA.
Joshua D
JD
Rouch
Department of Surgery, Division of Pediatric Surgery, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, 90095, USA.
Nhan
N
Huynh
Department of Surgery, Division of Pediatric Surgery, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, 90095, USA.
Andrew
A
Scott
Department of Surgery, Division of Pediatric Surgery, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, 90095, USA.
Elvin
E
Chiang
School of Engineering, Department of Bioengineering, University of California, Los Angeles, Los Angeles, CA, 90095, USA.
Benjamin M
BM
Wu
Department of Surgery, Division of Pediatric Surgery, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, 90095, USA.
Shant
S
Shekherdimian
Department of Surgery, Division of Pediatric Surgery, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, 90095, USA; School of Engineering, Department of Bioengineering, University of California, Los Angeles, Los Angeles, CA, 90095, USA. Electronic address: jdunn@mednet.ucla.edu.
James C Y
JC
Dunn
D020341:Absorbable Implants; D000818:Animals; D001696:Biomechanical Phenomena; D004195:Disease Models, Animal; D005240:Feasibility Studies; D007583:Jejunum / Q000601:surgery*; D011091:Polyesters; D012778:Short Bowel Syndrome / Q000601:surgery*; D034421:Sus scrofa; D015626:Tissue Expansion / Q000295:instrumentation* / Q000379:methods; D015625:Tissue Expansion Devices
D011091:Polyesters; C016240:polycaprolactone
Distraction enterogenesis; Hooke's law; Mechanical enterogenesis; Short bowel syndrome