title: Evaluation in an animal model of a hybrid covered metallic ureteral stent: a new design.
abstract: OBJECTIVE
  To evaluate a new design for a hybrid, dynamic, metallic ureteral stent that might avoid the formation of urothelial hyperplasia after ureteral metallic stenting in an experimental study.
  
  
  METHODS
  A total of 30 healthy female pigs were included in the present study, and an experimental obstructive uropathy in the right lumbar ureter was created in each pig. Obstruction was confirmed using percutaneous ultrasonography and retrograde ureteral pyelography and endoluminal ultrasonography 6 weeks after obstructive uropathy model creation. Then, the pigs were randomly distributed into 2 groups. Group 1 underwent standard metallic ureteral self-expanding internally covered stent deployment. Group 2 received a new hybrid metallic ureteral self-expanding internally covered stent. The follow-up period was 6 months.
  
  
  RESULTS
  The hybrid metallic ureteral self-expanding internally covered stent group had a lower rate of urothelial hyperplasia (21% vs 70%), reduced stent migration (6.6% vs 33.3%), and a greater success rate after 6 months of follow-up (86.6% vs 47%) compared with the standard metallic ureteral self-expanding internally covered stent deployment group, with statically significant differences between the 2 groups.
  
  
  CONCLUSIONS
  Our experimental results have indicated that the use of the hybrid metallic ureteral self-expanding internally covered stent in ureteral strictures is feasible, safe, and effective and reduces the formation of urothelial hyperplasia without secondary interventions to maintain ureteral patency.
authors: Department of Endoscopy, Minimally Invasive Surgery Centre Jesús Usón, Cáceres, Spain. fsoria@ccmijesususon.com
authors: Federico
authors: F
authors: Soria
authors: Esther
authors: E
authors: Morcillo
authors: Manuel
authors: M
authors: Pamplona
authors: Jesus
authors: J
authors: Uson
authors: Francisco M
authors: FM
authors: Sanchez-Margallo
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D004867:Equipment Design; D005260:Female; D006965:Hyperplasia / Q000209:etiology* / Q000517:prevention & control; D008670:Metals; D011475:Prosthesis Failure; D018709:Statistics, Nonparametric; D015607:Stents / Q000009:adverse effects; D013552:Swine; D016896:Treatment Outcome; D014513:Ureter / Q000473:pathology* / Q000601:surgery*; D014517:Ureteral Obstruction / Q000601:surgery*; D019459:Urothelium / Q000473:pathology*
chemical_list: D008670:Metals