Histopathological evaluation of urethroplasty with dorsal buccal mucosa: an experimental study in rabbits

PURPOSE: Buccal mucosa is a widely accepted tissue for urethroplasty. The exact healing and tissue integration process, mainly the histological characteristics of dorsal buccal mucosa graft urethroplasty when used dorsally to reconstruct the urethral plate has not previously been assessed, and thus we developed an experimental model to address this question. MATERIALS AND METHODS: In 12 New Zealand rabbits (weight 2.5 kg) we surgically created a dorsal penile urethral defect. A buccal mucosa graft was sutured to the corpora and tunica albuginea, and the ventral urethra anastomosed to this new urethral plate. The animals were divided in three groups and sacrificed 1, 3 and 6 weeks after surgery (groups 1, 2 and 3). A retrograde urethrogram was obtained at autopsy in the last group and the penis analyzed histologically with hematoxylin-eosin and Masson's staining. RESULTS: The urethrograms showed no evidence of fistula or stricture. In group 1 the histopathological analysis showed submucosal lymph-mononuclear inflammatory edema, numerous eosinophils and squamous epithelium integrated into the adjacent urothelium. In group 2 there was no evidence of an inflammatory response but rather complete subepithelial hyaline healing, which was more marked in group 3. CONCLUSION: Healing of buccal mucosa grafts to reconstruct the urethral plate can be achieved by total integration of the squamous epithelium with the urothelium, maintaining the original histological properties of the graft with no fibrosis or retraction.

Kidney transplantation in children: a 50-case experience

OBJECTIVES: The aim of this article was to report our experience with kidney transplantation in children. MATERIALS AND METHODS: From June 1980 to December 2003, 690 kidney transplants were performed in our institution, among which 50 were in patients with less than 18 years old. Technical aspects as well as clinical and surgical evolution were reviewed in this study. RESULTS: Patient's mean age was 12 years (2-17 years). Twenty-nine patients were male and 21 female. Live related donors were responsible for 75 percent of the cases (38 patients) and 25 percent (12 patients) came from cadaver donors. The main complications were ureteral fistula in 6 patients (12 percent), arterial stenosis in 2 (4 percent), wall infection and dehiscence in 1 case (2 percent). The overall rate of surgical complication was 20 percent. No case of hyperacute rejection was reported. During the follow-up 20 grafts were lost due to chronic rejection and 2 patients died. No loss of graft due to surgical complications was reported. The graft survival rate was 71 percent in 1 year, 64 percent in 3 years and 57 percent in 5-year follow-up. CONCLUSIONS: Kidney transplantation in children is a viable treatment option for terminal kidney disease presenting success and surgical complication rate similar to kidney transplantation in adults.