title: Single-step renal dilatation in percutaneous nephrolithotomy: A prospective randomised study.
abstract: OBJECTIVE
  To perform an economical single-step renal dilatation (RD) during percutaneous nephrolithotomy (PCNL), using directly a 30-F Amplatz dilator over the central Alken dilator, in a trial to reduce the operative duration and radiation exposure during RD while avoiding an exchange of dilators that might increase the risk of blood loss.
  
  
  METHODS
  In a prospective randomised study including 49 patients divided into two groups, the first had RD before PCNL using the standard metallic telescopic dilators (Alken), and the second had RD using the 30-F Amplatz dilator over the central Alken dilator. The operative duration, with X-ray exposure, was calculated. The procedure outcome in terms of complications, stone-free rates and hospital stay was evaluated statistically.
  
  
  RESULTS
  The tract was dilated correctly in all cases. The operative duration and X-ray exposure was shorter in patients undergoing single-step RD (P < 0.05). There were perioperative complications, according to the Clavien grading system, in 17 (34%) patients but there was no statistically significant difference between the groups. The stone-free rates were comparable in both groups.
  
  
  CONCLUSIONS
  A single-step RD during PCNL is feasible, with a shorter operative duration and X-ray exposure. The outcomes were comparable with those of a standard metallic telescopic RD.
authors.affiliation: Department of Urology, Theodor Bilharz Research Institute, Guiza, Egypt.
authors.forename: Hani H
authors.initials: HH
authors.lastname: Nour
authors.affiliation: Department of Urology, Theodor Bilharz Research Institute, Guiza, Egypt.
authors.forename: Ahmad M
authors.initials: AM
authors.lastname: Kamal
authors.affiliation: Department of Urology, Theodor Bilharz Research Institute, Guiza, Egypt.
authors.forename: Ahmad S
authors.initials: AS
authors.lastname: Zayed
authors.affiliation: Department of Urology, Theodor Bilharz Research Institute, Guiza, Egypt.
authors.forename: Hisham
authors.initials: H
authors.lastname: Refaat
authors.affiliation: Department of Urology, Theodor Bilharz Research Institute, Guiza, Egypt.
authors.forename: Mohamed H
authors.initials: MH
authors.lastname: Badawy
authors.affiliation: Department of Urology, Theodor Bilharz Research Institute, Guiza, Egypt.
authors.forename: Tarek R
authors.initials: TR
authors.lastname: El-Leithy
keywords: BMI, body mass index; Fascial dilators; PCNL, percutaneous nephrolithotomy; RD, renal dilatation; Renal dilatation; Single-step; Telescopic dilators