title: Histologic changes after urethroplasty using small intestinal submucosa unseeded with cells in rabbits with injured urethra.
abstract: OBJECTIVE
  To determine whether small intestine submucosa has the same regenerative capacity when urethroplasty is performed in injured urethras.
  
  
  METHODS
  Our experiment was conducted in 30 New Zealand male rabbits, all of which had urethral injury. One month after the injury, the animals were randomized into a control group or a group with onlay urethroplasty with small intestine submucosa. The animals were euthanized at 2, 4, 12, 24, and 36 weeks after urethroplasty, and their urethras were removed for histologic and immunohistochemical examination. Before the scheduled euthanasia, urethrography and cystoscopy were performed.
  
  
  RESULTS
  After 2 weeks, there was evidence of a continuous monolayer of stratified epithelial cells and absence of smooth muscle fibers. One month later, the epithelium showed no changes from the previously observed features, but some smooth muscle fibers (representing newly formed vessels) became apparent. After 3 months, the graft showed increased concentration of smooth muscle fibers. After 6 and 9 months, the density of smooth muscle cells remained unchanged. Fiber arrangement was irregular, particularly at the anastomosis site. Epithelial and smooth muscle phenotypes were confirmed by immunohistochemistry using anti-pan-citokeratin (AE1/AE3) antibodies and anti-α-smooth muscle actin, respectively.
  
  
  CONCLUSIONS
  Small intestine submucosa promotes regeneration in traumatized urethras, with slightly delayed epithelialization and abnormal distribution of smooth muscle. Urethral damage caused by trauma interferes with the normal healing process.
authors.affiliation: Department of Urology, Italian Hospital of Buenos Aires, Argentina. gustavo.villoldo@hospitalitaliano.org.ar
authors.forename: Gustavo Martín
authors.initials: GM
authors.lastname: Villoldo
authors.forename: Mónica
authors.initials: M
authors.lastname: Loresi
authors.forename: Carlos
authors.initials: C
authors.lastname: Giudice
authors.forename: Oscar
authors.initials: O
authors.lastname: Damia
authors.forename: Juan Manuel
authors.initials: JM
authors.lastname: Moldes
authors.forename: Francisco
authors.initials: F
authors.lastname: DeBadiola
authors.forename: Mariana
authors.initials: M
authors.lastname: Barbich
authors.forename: Pablo
authors.initials: P
authors.lastname: Argibay
mesh_terms: D000818:Animals; D001672:Biocompatible Materials; D003558:Cystoscopy; D004848:Epithelium / Q000473:pathology / Q000502:physiology*; D007421:Intestine, Small / Q000637:transplantation*; D008297:Male; D009130:Muscle, Smooth / Q000473:pathology / Q000502:physiology*; D011817:Rabbits; D012038:Regeneration; D013552:Swine; D013997:Time Factors; D014183:Transplantation, Heterologous; D014521:Urethra / Q000293:injuries / Q000473:pathology* / Q000502:physiology* / Q000601:surgery
chemical_list: D001672:Biocompatible Materials