title: Minimally invasive percutaneous nephrolithotomy in children less than three years of age: five-year experience in 234 cases.
abstract: OBJECTIVE
  The treatment of infant renal stones is still a huge challenge to the urologist. The present study aimed to evaluate the safety and efficiency of the minimally invasive percutaneous nephrolithotomy (MPCNL) method as a treatment for infant renal stones, and also to analyze the specific techniques and related complications of the procedure.
  
  
  METHODS
  From January 2008 to December 2012, 234 cases (72 girls and 162 boys, mean age 15.8 months, range 5-36 months) aged under 3 years and treated with MPCNL for renal stones were analyzed retrospectively. 125 cases were younger than 12 months, 67 cases were between 13 and 24 months and 42 cases between 25 and 36 months. The indications for MPCNL were (1) stone over 1 cm(2), (2) hydronephrosis and (3) recurrent urinary tract infection. An initial percutaneous access to the targeted renal calyx was obtained through an ultrasound-guided peripheral calyceal puncture. Stones were fragmented by a holmium laser with a pediatric nephroscope via 14-F tract.
  
  
  RESULTS
  All the procedures were performed by single tract, and totally 247 tracts were established, including 245 14-F tracts, 1 16-F tract and 1 12-F tract, respectively. The stones were located in the left kidney (n = 91), right kidney (n = 105) and in both kidneys (n = 28), respectively. Regarding the puncture point, in 228 cases it was in the 12th subcostal space and in 19 cases in the 11th intercostal space. The distribution of target puncture calyx and the subsequent residual calculi were as follows: 39 cases in the upper calyx with 2 cases of stone residual, 148 in the middle calyx with 3 stone residuals, and 60 in the lower calyx with 2 stone residuals, respectively. As a result, completely stone-free state was achieved in 240 kidney units (97.2%). The mean operating time was 32.5 min. None of the patients required blood transfusion and no septic shock occurred after operation. A large quantity of washing fluid was infiltrated into the abdominal cavity in 3 cases.
  
  
  CONCLUSIONS
  Using a single tract ≤14 F, MPCNL is a safe and effective procedure in the management of renal stones in infant less than 3 years old.
authors.affiliation: Department of Urology, First Affiliated Hospital, Xinjiang Medical University, Urumqi, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Wang
authors.forename: Heng-Qing
authors.initials: HQ
authors.lastname: An
authors.forename: Jia
authors.initials: J
authors.lastname: Li
authors.forename: Cui-Yun
authors.initials: CY
authors.lastname: Tian
authors.forename: Yu-Jie
authors.initials: YJ
authors.lastname: Wang
mesh_terms: D002675:Child, Preschool; D005260:Female; D006801:Humans; D006869:Hydronephrosis / Q000601:surgery / Q000628:therapy; D007223:Infant; D007668:Kidney / Q000473:pathology; D007669:Kidney Calculi / Q000601:surgery / Q000628:therapy*; D007834:Lasers; D008297:Male; D019060:Minimally Invasive Surgical Procedures / Q000379:methods*; D009403:Nephrostomy, Percutaneous / Q000379:methods*; D061214:Patient Safety; D012189:Retrospective Studies; D016896:Treatment Outcome; D014463:Ultrasonography; D014552:Urinary Tract Infections / Q000628:therapy