Treatment of posterior hypospadias by the autologous graft of cultured urethral epithelium.

Keratinocytes derived from normal human skin can be cultivated in vitro to form a stratified patch of epidermis suitable for grafting on the sites of burns and skin defects caused by the removal of giant nevi or chronic leg ulcers. Autologous skin keratinocytes have been successfully used to line the mastoid cavities of patients with postoperative otorrhea. In vitro experiments and long-term studies of burn patients treated with autografts grown in vitro from cultured cells suggest that keratinocytes possess an intrinsic capacity for site-specific differentiation that is fully expressed when grafts of cultured epidermis are transplanted to different parts of the body. Epithelial cells derived from the palate and cultivated in vitro are also capable of reconstituting palatal epithelium after transplantation. These findings prompted us to investigate the possibility of culturing urethral cells to form urethral mucosa in vitro. We report here the reconstitution in vitro of human urethral mucosa and the subsequent successful autologous transplantation of it to form the anterior urethra in two patients with congenital hypospadias.