title: Outcome of ureteroscopy for stone disease in patients with horseshoe kidney: Review of world literature.
abstract: OBJECTIVE
  The management of urolithiasis in patients with horseshoe kidney (HSK) is difficult. Stone formation occurred in 1:5 patients with HSK due to impaired urinary drainage and infections. Percutaneous nephrolithotomy and shock wave lithotripsy can be technically challenging due to altered anatomy.
  
  
  METHODS
  We conducted a systematic review of the literature to look at the role of ureteroscopy for stone management in these patients. We searched MEDLINE, PubMed and the Cochrane Library from January 1990 to April 2013 for results of ureteroscopy and stone treatment in HSK patients. Inclusion criteria were all English language articles reporting on ureteroscopy in patients with HSK. Data were extracted on the outcomes and complications.
  
  
  RESULTS
  A total of 3 studies was identified during this period. Forty-one patients with HSK underwent flexible ureteroscopy and stone treatment. The mean age was 42 with a male:female ratio nearly 3:1. The mean stone size was 16 mm (range: 3-35 mm). The mean operating time was 86 min with multiple stones seen in 15 patients. All 41 patients had a ureteral access sheath used and flexible ureteroscopy and holmium laser fragmentation done. Thirty-two (78%) patients were stone-free with a mean hospital stay of 1-day. Minor complications (Clavien I or II) were seen in 13 (32%) of which 6 had stent discomfort, 3 needed intravenous antibiotics for <24 h, 3 had hematuria of which 2 needed blood transfusion and one had pyelonephritis needing re-admission and antibiotics. There were no major complications found in the review.
  
  
  CONCLUSIONS
  Retrograde stone treatment using ureteroscopy and lasertripsy in HSK patients can be performed with good stone clearance rate, but with a slightly higher complication rate. This procedure should, therefore, be done in high volume stone center with an experienced stone surgeon/team.
authors.affiliation: Department of Urology, University Hospital Southampton NHS Trust, Southampton, United Kingdom.
authors.forename: Hiro
authors.initials: H
authors.lastname: Ishii
authors.affiliation: Department of Urology, Ninewells Hospital, Dundee, Scotland.
authors.forename: Bhavan
authors.initials: B
authors.lastname: Rai
authors.affiliation: Department of Urology, University Pierre et Marie Curie Paris 6, Paris, France.
authors.forename: Olivier
authors.initials: O
authors.lastname: Traxer
authors.affiliation: Department of Urology, Ninewells Hospital, Dundee, Scotland.
authors.forename: Slawomir G
authors.initials: SG
authors.lastname: Kata
authors.affiliation: Department of Urology, University Hospital Southampton NHS Trust, Southampton, United Kingdom.
authors.forename: Bhaskar K
authors.initials: BK
authors.lastname: Somani
keywords: Laser fragmentation; horseshoe kidney; outcomes; stones; ureterorenoscopy