Pathomorphological restructuring of the buccal mucosa grafts during ureteroplasty (experimental and clinical study)

Abstract

BACKGROUND: Currently for the plastic surgery of extended strictures of the pyeloureteral segment and proximal ureter a grafts from the buccal mucosa is used. Histological changes in these grafts in the postoperative period have not been sufficiently studied. AIM: is to study the histological changes in the graft from the buccal mucosa used for ureteroplasty in an experiment and in patients at different times after surgery. MATERIALS AND METHODS: The experimental part of the study was carried out on 10 animals (rabbits). We studied histological changes in the wall of the buccal mucosa graft used for ureteroplasty. Under general anesthesia a median laparotomy was performed, the ureter was mobilized along the middle third, a defect of about 1 cm was created. Next a buccal graft of 1.5 × 1 cm was cut out, which was sutured to the ureteral defect using the onlay technique. After 6 months nephroureterectomy was performed. Three parts of the ureter were identified: the replacement zone, 3 cm sections above and below it, followed by histological examination. The clinical part of the study consisted of a histological examination of biopsy samples obtained from 5 patients during ureteroscopy by pinching graft biopsy 12 months and 24 months after buccal ureteroplasty. RESULTS: The experimental part of the study demonstrated the possibility and effectiveness of ureteroplasty with a buccal graft, and also revealed the restructuring of squamous epithelium into transitional cell. In patients 12 and 24 months after buccal ureteroplasty similar changes in the mucous membrane of the graft were not observed, therefore, further study of the mucous membrane of the buccal graft in later postoperative periods is necessary. CONCLUSIONS: The results of experimental and clinical studies indicate the possibility of using a graft from the buccal mucosa for plastic surgery of extensive and recurrent ureteral strictures. Unlike animals, where a restructuring of squamous to transitional cell epithelium was observed, similar morphological changes did not occur in patients after buccal ureteroplasty.