Purpose: We examined the mechanisms responsible for technical failure of the endoscopic technique for correcting vesicoureteral reflux based on endoscopic anatomy.
Materials and methods: The study included 25 patients, 2 to 15 years old (mean age 8) who received 57 ureteral injections on 1 or more occasions which failed to correct reflux. Each endoscopic procedure for every patient was videotaped and endoscopic photographs were taken to document pretreatment and posttreatment anatomy. Based on the comparative endoscopic anatomical findings, failures were categorized as secondary to volume loss, mound displacement, mound extrusion or indeterminate etiology.
Results: Of the 57 ureters the cause of failure was believed to be due to mound displacement in 35%, volume loss in 23%, displacement and volume loss in 29%, mound extrusion in 2% and indeterminate in 11%. The direction of mound displacement was toward the bladder neck (medial, distal) in 76% of those cases.
Conclusions: Endoscopic anatomical findings can account for failure of the injection technique to correct reflux in the majority of failed cases (90%). Mound displacement and volume loss account comparably for treatment failure. One incidence of mound extrusion, previously hypothesized as a mechanism for treatment failure, was documented in our study.