Dongho Hyun1, Hong Suk Park2, Soowon Seo3, In Wook Choo1, Sooyoun Lim1, Mi Hyun Nam4, Young Soo Do1, Sung Wook Choo1, Sung Wook Shin1, Kwang Bo Park1, Sung Ki Cho1. 1. Department of Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea. 2. Department of Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea. Electronic address: hongsukpark@gmail.com. 3. Medical Device Development Center, Daegu-Gyeongbuk Medical Innovation Foundation, Daegu, Korea. 4. Laboratory Animal Research Center, Samsung Biomedical Research Institute, Seoul, Korea.
Abstract
BACKGROUND: The need for newer gastrointestinal (GI) stents has been continuously raised. Newly developed stents are generally tested for physical properties in vitro and directly introduced to clinical practice because there is no reliable animal model of GI obstruction. The aim of this study was to establish an animal model both that can represent obstruction of the GI tract and be used to develop new stents. MATERIAL AND METHODS: Surgical obstruction of the descending colon by wrapping with a nonabsorbable synthetic mesh and rubber bands was made in 17 healthy mongrel dogs. Four days later, a covered self-expanding metallic stent was placed for the obstructed segment in each dog under fluoroscopic guidance. Patency and migration of the inserted stents were evaluated clinically on a daily basis and fluoroscopically on a weekly basis. After sacrifice of the dogs, the degree and extent of residual colonic obstruction were assessed fluoroscopically. The specimen of the colonic obstructed segment was examined microscopically. RESULTS: In all 17 mongrel dogs, segmental obstruction in the descending colon was successfully created and confirmed with fluoroscopic examination using a contrast medium. The percentage of luminal narrowing ranged from 99%-100%. Stent placement was technically successful in all 17 dogs. During the follow-up period, stent migration occurred in 12 dogs and indwelling time of a stent ranged from 0-95 d (mean 29.2 ± 38.8 d). On postmortem pathologic examination, it was found that fibrosis had newly formed outside the colonic longitudinal muscle layer in all dogs. CONCLUSIONS: Our canine colonic obstruction model is the first animal model that can be feasible for developing a new design of stent and provide in vivo data on complications, particularly stent migration.
BACKGROUND: The need for newer gastrointestinal (GI) stents has been continuously raised. Newly developed stents are generally tested for physical properties in vitro and directly introduced to clinical practice because there is no reliable animal model of GI obstruction. The aim of this study was to establish an animal model both that can represent obstruction of the GI tract and be used to develop new stents. MATERIAL AND METHODS: Surgical obstruction of the descending colon by wrapping with a nonabsorbable synthetic mesh and rubber bands was made in 17 healthy mongrel dogs. Four days later, a covered self-expanding metallic stent was placed for the obstructed segment in each dog under fluoroscopic guidance. Patency and migration of the inserted stents were evaluated clinically on a daily basis and fluoroscopically on a weekly basis. After sacrifice of the dogs, the degree and extent of residual colonic obstruction were assessed fluoroscopically. The specimen of the colonic obstructed segment was examined microscopically. RESULTS: In all 17 mongrel dogs, segmental obstruction in the descending colon was successfully created and confirmed with fluoroscopic examination using a contrast medium. The percentage of luminal narrowing ranged from 99%-100%. Stent placement was technically successful in all 17 dogs. During the follow-up period, stent migration occurred in 12 dogs and indwelling time of a stent ranged from 0-95 d (mean 29.2 ± 38.8 d). On postmortem pathologic examination, it was found that fibrosis had newly formed outside the colonic longitudinal muscle layer in all dogs. CONCLUSIONS: Our caninecolonic obstruction model is the first animal model that can be feasible for developing a new design of stent and provide in vivo data on complications, particularly stent migration.
Authors: Jin Ho Hwang; Hong Suk Park; Soowon Seo; In Wook Choo; Young Soo Do; Sung Wook Choo; Sung Wook Shin; Kwang Bo Park; Sung Ki Cho; Dongho Hyun; Sooyoun Lim Journal: Biomed Res Int Date: 2015-08-20 Impact factor: 3.411