title: Single-step percutaneous nephrolithotomy (microperc): the initial clinical report.
abstract: OBJECTIVE
  To our knowledge we report the first technical feasibility and safety study of 1-step percutaneous nephrolithotomy using the previously described 4.85Fr all-seeing needle (PolyDiagnost, Pfaffenhofen, Germany). We defined microperc as modified percutaneous nephrolithotomy in which renal access and percutaneous nephrolithotomy are done in 1 step using the all-seeing needle.
  
  
  METHODS
  Microperc was performed in 10 cases using the 4.85Fr all-seeing needle to achieve collecting system access under direct vision. Percutaneous nephrolithotomy was done through the same 16 gauge needle sheath with a 3-way connector allowing irrigation, and passage of a flexible telescope and a 200 μm holmium:YAG laser fiber. We prospectively analyzed preoperative, intraoperative and postoperative parameters.
  
  
  RESULTS
  Mean calculous size was 14.3 mm. Two of the 10 patients were of pediatric age, and 1 each had an ectopic pelvic kidney, chronic kidney disease and obesity. Microperc was feasible in all cases with mean ± SD surgeon visual analog score for access of 3.1 ± 1.2, a mean 1.4 ± 1.0 gm/dl hemoglobin decrease and a mean hospital stay of 2.3 ± 1.2 days. The stone-free rate at 1 month was 88.9%. In 1 patient intraoperative bleeding obscured vision, requiring conversion to mini percutaneous nephrolithotomy. There were no postoperative complications and no auxiliary procedures were required.
  
  
  CONCLUSIONS
  Microperc is technically feasible, safe and efficacious for small volume renal calculous disease. Further clinical studies and direct comparison with available modalities are required to define the place of microperc in the treatment of nonbulky renal urolithiasis.
authors.affiliation: Department of Urology, Muljibhai Patel Urological Hospital, Gujarat, India. mrdesai@mpuh.org
authors.forename: Mahesh R
authors.initials: MR
authors.lastname: Desai
authors.forename: Rajan
authors.initials: R
authors.lastname: Sharma
authors.forename: Shashikant
authors.initials: S
authors.lastname: Mishra
authors.forename: Ravindra B
authors.initials: RB
authors.lastname: Sabnis
authors.forename: Christian
authors.initials: C
authors.lastname: Stief
authors.forename: Markus
authors.initials: M
authors.lastname: Bader
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D004867:Equipment Design; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007669:Kidney Calculi / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D009339:Needles; D009403:Nephrostomy, Percutaneous / Q000295:instrumentation / Q000379:methods*; D011446:Prospective Studies; D055815:Young Adult