Résumé : Endoscopic correction of vesicoureteric reflux in children has been performed in several hundred cases with the use of Teflon or cross-linked bovine collagen. The main criticism to this simple procedure is the potential migration of Teflon particles and the local pathological reaction. An experimental study was performed in 20 rabbits injected with Teflon or collagen in the bladder submucosa. A pathological examination of the bladder, lymph nodes, liver, lungs and brain was performed several months after the experiment to study the migration and the local reaction. There is no local granulomatous reaction with collagen while a local granulomatous reaction is found in the site of injection of Teflon and in 1 locoregional lymph node. The colonization of collagen by histiocytes increases with time. No distant granulomatous reaction was noted with both injections on histological examination. A mineralogic technique was applied after homogenisation of the lungs and brain to further investigate the distant migration problem. Rare particles of Teflon were observed in the lungs but not in the brain. The pathological significance of these particles remains unclear, but calls for research for different injection materials.