[Urethroplasty using appendiceal mucosa. A preliminary study of urethroplasty using free colonic mucosa in rats].

The use of skin, buccal or vesical mucosa for free graft urethroplasties is associated with a high incidence of postoperative stenosis and fistulas. In order to develop a new urethral substitute, the appendicular mucosa is proposed as a new material. As animals do not possess an appendix, an animal model of colonic mucosa urethroplasty was used in this study. Forty rats were submitted to distal segmental urethrectomy. For 14 rats, a simple urethral catheter was inserted without urethroplasty (group I), for 7 rats, urethroplasty was performed using a collagen tube (group II), and for 19 rats, a free colonic mucosa urethroplasty was performed (Group III). After 3 to 6 weeks, a microscopic and macroscopic study was performed. A newly formed urethra was only observed in the last group (Group III). Histological examination visualized a typical non-secreting urothelium. In the light of this study, free gastrointestinal mucosa appears to be suitable for urethroplasties. Until a human clinical application is developed, early histological studies will probably help to explain the development of this neo-urothelium, which remains hypothetical at the present time.