title: Can a graft be placed over a flap in complex hypospadias surgery? An experimental study in rabbits.
abstract: OBJECTIVE
  To develop a rabbit experimental study to test the hypothesis that surgical repair of hypospadias with severe ventral curvatures might be completed in one stage, if a graft, such as buccal mucosa, could be placed over the tunica vaginalis flap used in corporoplasty for ventral lengthening, with the addition of an onlay preputial island. flap to complete the urethroplasty.
  
  
  METHODS
  The experimental procedure with rabbits included a tunica vaginalis flap for reconstruction of the corpora after corporotomy, simulating a ventral lengthening operation. A buccal mucosa graft was placed directly on top of the flap, and the urethroplasty was completed with an onlay preputial island flap. Eight rabbits were divided into 4 groups, sacrificed at 2, 4, 8 and 12 weeks postoperatively, and submitted to histological evaluation.
  
  
  RESULTS
  We observed a large number of complications, such as fistula (75%), urinary retention (50%) and stenosis (50%). There were two deaths related to the procedure. Histological evaluation demonstrated a severe and persistent inflammatory reaction. No viable tunica vaginalis or buccal mucosa was identified.
  
  
  CONCLUSIONS
  In this animal model, the association of a buccal mucosa graft over the tunica vaginalis flap was not successful, and resulted in complete loss of both tissues.
authors.affiliation: Universidade Federal de São Paulo, São Paulo, Brasil.
authors.forename: Ricardo Marcondes de
authors.initials: RM
authors.lastname: Mattos
authors.affiliation: Universidade Estadual Paulista, Botucatu, Brasil.
authors.forename: Sérgio R R de
authors.initials: SR
authors.lastname: Araújo
authors.affiliation: Universidade Estadual Paulista, Botucatu, Brasil.
authors.forename: Juliany Gomes
authors.initials: JG
authors.lastname: Quitzan
authors.affiliation: Universidade Federal de São Paulo, São Paulo, Brasil.
authors.forename: Bruno
authors.initials: B
authors.lastname: Leslie
authors.affiliation: Universidade Federal de São Paulo, São Paulo, Brasil.
authors.forename: Herick
authors.initials: H
authors.lastname: Bacelar
authors.affiliation: Universidade Federal de São Paulo, São Paulo, Brasil.
authors.forename: João Luiz Gomes
authors.initials: JL
authors.lastname: Parizi
authors.affiliation: Universidade Federal de São Paulo, São Paulo, Brasil.
authors.forename: Gustavo Marconi Caetano
authors.initials: GM
authors.lastname: Martins
authors.affiliation: Universidade Federal de São Paulo, São Paulo, Brasil.
authors.forename: Marcela Leal da
authors.initials: ML
authors.lastname: Cruz
authors.affiliation: Universidade Federal de São Paulo, São Paulo, Brasil.
authors.forename: Antonio
authors.initials: A
authors.lastname: Macedo
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D004848:Epithelium / Q000473:pathology; D005355:Fibrosis; D007021:Hypospadias / Q000473:pathology / Q000601:surgery*; D007249:Inflammation; D008297:Male; D011183:Postoperative Complications; D011817:Rabbits; D013524:Surgical Flaps / Q000601:surgery*; D014521:Urethra / Q000601:surgery*; D014548:Urinary Fistula / Q000209:etiology / Q000473:pathology; D013521:Urologic Surgical Procedures, Male / Q000379:methods*
keywords: Hypospadias; Urogenital Abnormalities; Urologic Surgical Procedures