Do Topical Androgens and Their Timing Affect the Survival of Buccal Mucosa Grefts in Hypospadias Repair
Abstract Purpose Buccal mucosa is prefered to form a neourethra in some hypospadias cases when required. However survival of these grefts and thus the success of the repair are variable We hypothesized that topical Testosteron(T) or Dihydrotestosteron(DHT) application (prior or after grafting) on the urethral plate known to have androgen receptors might improve graft survival and angiogenesis. We also evaluated the angiogenetic and proliferative responses of isolated buccal mucosa and urethral plate explants to T and DHT seperately in vitro by tissue culture. Material and Methods After 30 New Zeland rabbits were surgically made hypospadiac topical(T)&(DHT) were applied prior to grafting for Groups 1and2 respectively at a standard dose and duration.T &DHT were administrated after the grafting for Group 3 and 4 respectively. Group 5 was control. For tissue culture, 3 buccal mucosa and 3 urethral plate samples taken from each of10 rabbits were explanted and different titrations of T orDHT added or control media. Immunohistochemically survival of invivo and invitro tissue samples were investigated with proliferation marker(Ki-67), & angiogenesis marker(CD31). Results In vivo experiments revealed highest Ki-67 and CD31scores for DHT prior to grefting group (p Conclusions Topical administration ofDHT prior to grafting increases buccal mucosa graft survival due to increased angiogenesis in the urethral plate.