Current Issue UroToday Int J. 2009 Oct;2(5). doi:10.3834/uij.1944-5784.2009.10.07
Post-Tubularized Incised Plate Urethroplasty Healing: An Experimental Randomized Study in 40 Dogs
INTRODUCTION: The mechanism of urethral healing after tubularized incised plate urethroplasty (TIP) is still debatable. The purpose of the present study was to report post-TIP healing in a randomized-study hypospadias dog model.
METHODS: The hypospadias model was created in 40 male mongrel dogs that were randomly allocated into group 1 and group 2 with 20 dogs in each, and 4 subgroups (1a and 1b; 2a and 2b) with 10 dogs in each. The urethral plate width was reduced to 10 mm and 6 mm in group 1 and group 2, respectively. The urethral plate (UP) was tattooed and bisected by midline longitudinal incision. The length of UP and urethral incision (UI) was 2 cm in subgroups 1a and 2a and 4 cm in subgroups 1b and 2b. Tubularization of UP was done over an 8 Fr feeding tube. After 4 weeks, the phallus was harvested and transverse sections were obtained from the area of UI. They were stained by hematoxylin and eosin (H&E), Masson's trichrome, and fibronectin stains and pathologically examined.
RESULTS: Four cases of proximal urethral fistulae were reported in group 2 (1 in subgroup 2a; 3 in subgroup 2b). Gross inspection exhibited intervening tissues at the site of UI. The size of the intervening tissues between the healing edges of the UI was 0.8 mm (SD = 0.1) in group 1 and 2.5 mm (SD = 0.2) in group 2. Light microscopy revealed creeping of normal-appearing squamous surface epithelium in all specimens. Increased collagen fiber deposition was recorded in group 2 when compared with group 1. Fibronectin was expressed in the subepithelial locations of the urethra in all studied animals. However, dense signals were reported in group 2 in comparison to group 1.
CONCLUSIONS: Healing after TIP occurs by secondary intention with creeping of the surface epithelium. Collagen deposition was increased in cases of UP ≤ 6 mm in width. Post-TIP complications may increase in cases of narrow UP, especially with the neourethra and UI > 2 cm in length.
KEYWORDS: Urethra; Hypospadias; Dog; Healing.
CORRESPONDENCE: Dr. Hisham Hammouda, Director of the Pediatric Urology Unit, Urology Department, Faculty of Medicine, Assiut University Hospital, 71111, Assiut, Egypt (Hammouda_64@yahoo.com).
CITATION: UroToday Int J. 2009 Oct;2(5). doi:10.3834/uij.1944-5784.2009.10.07
|
UroToday, 1802 Fifth Street, Berkeley CA 94710 Privacy Policy | © 2009 UroToday ® All Rights Reserved |
