title: Endoscopic Management of Urolithiasis in the Horseshoe Kidney.
abstract: OBJECTIVE
  To assess the endourologic outcomes of patients diagnosed with a horseshoe kidney (HK) and symptomatic urolithiasis.
  
  
  METHODS
  A retrospective review was performed of patients diagnosed with an HK who underwent endoscopic management from 2002 to present.
  
  
  RESULTS
  We identified 45 patients with 64 stone-bearing moieties who underwent 56 procedures, of which 31 (69%) were male. Mean age was 49.4 years (23-78) and mean stone size was 1.6 cm (0.2-5.7). Of the 64 moieties, 37 (58%) underwent percutaneous nephrolithotomy (PCNL), 25 (39%) underwent ureteroscopy (URS), and 2 (3%) underwent extracorporal shockwave lithotripsy (SWL). More than one access was utilized in 2 (5.7%) moieties undergoing PCNL. Additional procedures were required in 10 (28.5%) PCNL patients, of which 7 were URS, 2 were secondary PCNL, and 1 sandwich therapy with SWL and PCNL. Stone-free rate by moiety was 81.1% for PCNL, 84% for URS, and 50% for SWL. Postoperative complications occurred in 3 patients in the PCNL group, including readmission for pain and complicated urinary tract infection. With a mean follow-up of 20.5 months (range 0-118 months), stone recurrence was noted in 7 (16%) patients with a total of 11 events. Calcium oxalate was the most common stone type and 20/24 (83%) of patients with metabolic evaluations were found to have at least one abnormality.
  
  
  CONCLUSIONS
  After careful consideration of the anatomy, individuals with HK and symptomatic urolithiasis can be managed safely by a variety of endoscopic approaches with excellent outcomes; however, secondary procedures and recurrence are common.
authors.affiliation: Department of Urology, Mayo Clinic, Rochester, MN.
authors.forename: Andrew T
authors.initials: AT
authors.lastname: Blackburne
authors.affiliation: Department of Urology, Mayo Clinic, Rochester, MN.
authors.forename: Marcelino E
authors.initials: ME
authors.lastname: Rivera
authors.affiliation: Department of Urology, Mayo Clinic, Rochester, MN.
authors.forename: Matthew T
authors.initials: MT
authors.lastname: Gettman
authors.affiliation: Department of Urology, Mayo Clinic, Rochester, MN.
authors.forename: David E
authors.initials: DE
authors.lastname: Patterson
authors.affiliation: Department of Urology, Mayo Clinic, Rochester, MN. Electronic address: krambeck.amy@mayo.edu.
authors.forename: Amy E
authors.initials: AE
authors.lastname: Krambeck
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D000069337:Fused Kidney / Q000150:complications*; D006801:Humans; D008096:Lithotripsy; D008297:Male; D008875:Middle Aged; D009403:Nephrostomy, Percutaneous; D012189:Retrospective Studies; D018666:Ureteroscopy; D052878:Urolithiasis / Q000150:complications* / Q000628:therapy*; D055815:Young Adult