OBJECTIVE: To evaluate the anatomy and histology of the ureterovesical junction resected during secondary surgical reimplantation for persistent reflux after failure of initial endoscopic treatment by polytetrafluoroethylene (Teflon) in 27 cases and polydimethylsiloxane (Macroplastique) in 13 cases.
MATERIAL AND METHOD: 61 ureterovesical junctions from 40 children were studied histologically. The mean age of the patients at the time of the operation was 4.1 years (range: 1 to 15 years). The mean interval between endoscopic injection and surgical reimplantation was 15.3 months (range: 2 to 54 months).
RESULTS: Persistent reflux was not correlated with the anatomical situation of the implant, which was found to be in a satisfactory position in 52.4% of cases. Both of the substances used induced a giant-cell macrophage reaction which colonized the implant and triggered new vessel formation. Macroplastique appeared to be associated with a more intense inflammatory reaction than Teflon. Despite the difference in particle size, the two substances induced a macrophage phenomenon characterized by microfragmentation into 6 micron particles. No conclusions can be drawn concerning distant migration, but this study showed rarefaction of particles which were replaced by fibrosis, the density of which was correlated with the age of the implant.
CONCLUSION: Extinction of the local reaction induced by the products used in this study appears to be long and the end of this process is unknown, which justifies prolonged surveillance of children treated for reflux by endoscopic submeatal injection.
Source: PubMed 11296630