title: Retrograde intrarenal surgery for the treatment of renal stones in children: factors influencing stone clearance and complications.
abstract: BACKGROUND
  Retrograde intrarenal surgery (RIRS) is a known option for the treatment of upper tract calculi with an excellent success. However, the reports of RIRS in prepubertal children are limited. In this study, we evaluated the factors which affected the success rate and the complications of RIRS at renal stone treatment in childhood.
  
  
  METHODS
  We retrospectively reviewed the records of children under 14 years old who underwent RIRS for renal stone disease between January 2009 and December 2012. Patients' age, gender, body mass index (BMI), stone size, stone location, stone number, intraoperative complications, stone free status, postoperative complications were recorded.
  
  
  RESULTS
  There were 80 ureterorenoscopic procedures performed in 58 renal units of 47 children (23 males and 24 females). The patients' ages ranged from 8 months to 14 years (mean age 4.7 ± 3.4 years). There was a difference in the distribution of symptoms in age groups. UTI was higher in the 1-4 years age group, abdominal pain was seen mostly in children aged 5-14 years. Multiple stones (included staghorn stone) were noted in 60.4% of patients. In 27.6% of patients, ureteral stones were accompanied by renal stones in our series. In the infancy group, cystine and staghorn stones were more frequently seen, mostly bilateral. After a single ureteroscopic procedure for intrarenal stones in children, we achieved stone free status in 50.9% of the ureters (n=26). After the repeated sessions, the stone clearance rate reached to 85.1%.
  
  
  CONCLUSIONS
  Retrograde intrarenal surgery can be used as a first line therapy to treat renal stones in children. This is especially important if an associated ureteral stone is present that requires treatment; or in patients with cystinuria, which is not favorably treated with ESWL. Complications were seen more frequently in patients with cystine stones. Extravasation was noted more frequently in patients admitted with UTIs. There was a significant relationship between the conversion to open procedures and the age groups, with most procedures occurring in infancy. The parents should be informed about the probability of multiple procedures to achieve stone free status.
authors: Ankara Child Diseases Hematology and Oncology Education and Research Hospital, Pediatric Surgery Clinic, Ziraat mah, İrfan Basbug cad. Kurtdereli sok, No:4 Diskapi, Ankara, Turkey. Electronic address: drmujdemazili@yahoo.com.
authors: Mujdem Nur
authors: MN
authors: Azili
authors: Ankara Child Diseases Hematology and Oncology Education and Research Hospital, Pediatric Surgery Clinic, Ziraat mah, İrfan Basbug cad. Kurtdereli sok, No:4 Diskapi, Ankara, Turkey.
authors: Fatma
authors: F
authors: Ozcan
authors: Pediatric Urology Department, Ziraat mah, İrfan Basbug cad. Kurtdereli sok, No:4 Diskapi, Ankara, Turkey.
authors: Tugrul
authors: T
authors: Tiryaki
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D004724:Endoscopy / Q000379:methods; D005260:Female; D006801:Humans; D007223:Infant; D007668:Kidney / Q000601:surgery*; D007669:Kidney Calculi / Q000601:surgery* / Q000628:therapy; D053844:Lasers, Solid-State; D008096:Lithotripsy / Q000379:methods; D008297:Male; D011183:Postoperative Complications; D012189:Retrospective Studies; D016896:Treatment Outcome; D014514:Ureteral Calculi / Q000601:surgery / Q000628:therapy; D014546:Urinary Catheterization
keywords: Childhood; Nephrolithiasis; Retrograde intrarenal surgery