title: Possible causes of unsuccessful endoscopic collagen treatment of vesicoureteric reflux in children.
abstract: OBJECTIVE
  The purpose of this prospective study was to identify possible causes of unsuccessful treatment of vesicoureteric reflux (VUR) in children by endoscopic collagen injection.
  
  
  METHODS
  Between February 1994 and September 1996, 130 primary VURs in 94 children aged 3-16 years were treated by endoscopic injection of collagen. Grade 2 VUR was found in 46 ureteric units, grade 3 in 55, and grade 4 in 11 ureteric units. Seventy-seven children had normal micturition, and 17 showed signs of an unstable bladder. The collagen injection was performed under general anaesthesia. All children had a follow-up assessment on average 5.1 months after the first injection of collagen. They were evaluated by micturition cystography and ultrasound examination of the urinary tract.
  
  
  RESULTS
  A single injection of collagen eliminated VUR in 74 (56.9%) cases. There was a statistically significant correlation between the grade of VUR and the success rate of collagen therapy (p < 0.01). The average amount of collagen used in cured and in noncured children was 0.55 and 0.76 ml, respectively (p < 0.01). Children with normal appearance of the ureteric orifice had significantly better results as compared with other children (p < 0.01). There was no statistically significant correlation between the success rate of treatment and the place of collagen injection or the shape of ureteric orifice following the injection. A statistically significant association, however, was found between the function of the lower urinary tract and the results of endoscopic collagen treatment for VUR (p < 0.05). Ultrasound showed no obstruction of the upper urinary tract.
  
  
  CONCLUSIONS
  High-grade VUR, incorrect technique of injection, and voiding dysfunction seem to be some of the possible causes of an unsuccessful endoscopic collagen treatment of VUR in children.
authors.affiliation: Division of Urology, Department of Surgery, University Medical Centre Ljubljana, Slovenia.
authors.forename: B
authors.initials: B
authors.lastname: Trsinar
authors.forename: D
authors.initials: D
authors.lastname: Cotic
authors.forename: C
authors.initials: C
authors.lastname: Oblak
mesh_terms: D000293:Adolescent; D016009:Chi-Square Distribution; D002648:Child; D002675:Child, Preschool; D003094:Collagen / Q000008:administration & dosage*; D004724:Endoscopy; D005260:Female; D006801:Humans; D007267:Injections; D008297:Male; D011446:Prospective Studies; D016896:Treatment Outcome; D014718:Vesico-Ureteral Reflux / Q000628:therapy*
chemical_list: D003094:Collagen