title: [Effects of preventive double-J stent placement in ureteral obstruction treatment with metal stents on animal model].
abstract: OBJECTIVE
  The purpose of this experimental study is to assess the additive effects of temporary JJ stent placement together with metal stents (MS) in the treatment obstructive uropathy, in order to reduce urothelial hyperplasia formation.
  
  
  METHODS
  Twenty-four pigs were included, and an experimental model of obstructive uropathy was created. Six weeks after obstructive uropathy model induction, ureteral obstruction was confirmed using ultrasonography, ureteropyelography and endoluminal ultrasound. Afterwards, animals were randomly distributed into 2 groups. Group I underwent covered MS placement and JJ ureteral stenting for 3 weeks. Animals in Group II received the same MS without simultaneous JJ stenting. The follow-up was at 3 weeks and at 6 months.
  
  
  RESULTS
  Incidence of urothelial hyperplasia was higher in Group I than Group II, but without statically significant differences. On the other hand, Group II showed a significantly higher degree of obstruction severity due to hyperplasia. The migration rate in both groups was 33.3% at the end of the study. Significant differences were shown on animals showing urinary tract infection (UTI) and hyperplasia against those with hyperplasia but no infection. There was a high rate of correlation between UTI and obstructive urothelial hyperplasia.
  
  
  CONCLUSIONS
  Placement of JJ ureteral catheter does not inhibit urothelial hyperplasia associated with placement of metal mesh stents, although it significantly reduces its obstructive severity in long-term follow-up. Urinary tract infection is directly related to the development and magnitude of the urothelial hyperplasia.
authors.affiliation: Investigadora de la Unidad de Endoscopia del Centro de Cirugía de Mínima Invasión Jesús Usón. Cáceres. Spain.
authors.forename: Esther
authors.initials: E
authors.lastname: Morcillo
authors.affiliation: Director Científico del Centro de Cirugía de Mínima Invasión Jesús Usón. Cáceres. Spain.
authors.forename: Francisco Miguel
authors.initials: FM
authors.lastname: Sánchez-Margallo
authors.affiliation: Service of Urology. Hospital Clínico San Carlos. Madrid. Spain.
authors.forename: Alvaro
authors.initials: A
authors.lastname: Serrano
authors.affiliation: Service of Urology. Hospital Morales Messeguer. Murcia. Spain.
authors.forename: Tomas
authors.initials: T
authors.lastname: Fernández-Aparicio
authors.affiliation: Service of Urology. Hospital 12 de Octubre. Madrid. Spain.
authors.forename: Manuel
authors.initials: M
authors.lastname: Pamplona
authors.affiliation: Coordinador de la Unidad de Endoscopia del Centro de Cirugía de Mínima Invasión Jesús Usón. Cáceres. Spain.
authors.forename: Federico
authors.initials: F
authors.lastname: Soria
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D005260:Female; D006965:Hyperplasia / Q000517:prevention & control; D008670:Metals; D011474:Prosthesis Design; D011897:Random Allocation; D015607:Stents / Q000009:adverse effects; D013552:Swine; D013997:Time Factors; D014517:Ureteral Obstruction / Q000601:surgery*; D014546:Urinary Catheterization; D019459:Urothelium / Q000473:pathology
chemical_list: D008670:Metals