title: Retrograde Endopyelotomy with Cutting Balloon™ for Treatment of Ureteropelvic Junction Obstruction in Infants.
abstract: OBJECTIVE
  The aim of this study is to analyze results of retrograde endopyelotomy with cutting balloon for treatment of ureteropelvic junction obstruction (UPJO) in infants.
  
  
  METHODS
  We routinely treat patients with UPJO under 18 months of age with retrograde high-pressure balloon dilatation of the pelviureteric junction (PUJ). During the procedure, in these cases where narrowing at the PUJ persists, endopyelotomy with cutting balloon is performed. Endopyelotomy is performed over guidewire with 5-mm Cutting Balloon™ under fluoroscopic control. Double-J stents is left in situ for 4 weeks. We retrospectively analyzed the postoperative, clinical, and radiological outcome infants treated with cutting balloon endopyelotomy between 2007 and 2015.
  
  
  RESULTS
  Sixteen patients required cutting balloon endopyelotomy to achieve complete resolution of narrowing of the waist observed during high-pressure balloon dilatation of the PUJ. Mean operative time was 35 ± 21 min (mean ± SD) and hospital stay was <24 h in all patients. Complete resolution of the narrowing at the PUJ under fluoroscopy was achieved in all cases, with no perioperative complications. One patient presented with urinary tract infection, postoperatively (Clavien grade II). Preoperatively, all cases had grade IV SFU hydronephrosis with parenchymal thinning. During follow-up, resolution of the hydronephrosis was observed in 11 patients (grade I SFU). In four infants, there was an improvement of the hydronephrosis (grade II SFU) and the renogram curve. In one case, an open pyeloplasty was required due to persistent hydronephrosis and obstructive curve.
  
  
  CONCLUSIONS
  We believe that endopyelotomy with cutting balloon could be a valid and safe option in minimally invasive management of UPJO in infants.
authors.affiliation: Paediatric Urology, Hospital General Universitario Gregorio Marañón , Madrid , Spain.
authors.forename: Alberto
authors.initials: A
authors.lastname: Parente
authors.affiliation: Paediatric Urology, Hospital General Universitario Gregorio Marañón , Madrid , Spain.
authors.forename: Laura
authors.initials: L
authors.lastname: Perez-Egido
authors.affiliation: Paediatric Urology, Hospital General Universitario Gregorio Marañón , Madrid , Spain.
authors.forename: Rosa Maria
authors.initials: RM
authors.lastname: Romero
authors.affiliation: Paediatric Urology, Hospital General Universitario Gregorio Marañón , Madrid , Spain.
authors.forename: Ruben
authors.initials: R
authors.lastname: Ortiz
authors.affiliation: Paediatric Urology, Hospital General Universitario Gregorio Marañón , Madrid , Spain.
authors.forename: Laura
authors.initials: L
authors.lastname: Burgos
authors.affiliation: Paediatric Urology, Hospital General Universitario Gregorio Marañón , Madrid , Spain.
authors.forename: Jose Maria
authors.initials: JM
authors.lastname: Angulo
keywords: balloon dilation; cutting; endopyelotomy; hydronephrosis; infant