Flexible ureterorenoscopy with holmium laser in horseshoe kidneys.

To assess the outcome of flexible ureterorenoscopy (F-URS) with the holmium laser in treating stones in the horseshoe kidney (HSK). We retrospectively reviewed the records of 17 patients with a HSK stone (17 renal units) who had undergone F-URS with the holmium laser from December 2004 to May 2009. The presenting symptoms were renal colic, urinary tract infection, or hematuria. F-URS was used in as an alternative after the failure of shock wave lithotripsy in 8 patients (47%) and percutaneous nephrolithotomy failure in 4 patients (23.5%). Follow-up examination was performed after 4-6 weeks with plain radiography and either renal ultrasonography or noncontrast computed tomography. Success was defined as stone-free status or residual fragments <3 mm. The use of auxiliary procedures was considered to indicate treatment failure. A total of 17 patients were included in the present study (3 females and 14 males). Their age was 16-52 years (mean age ± SD 34.7 ± 6.3). The HSK stone location was 7 mixed caliceal, 3 mixed pelvic and caliceal, and 7 pelvic. The average stone burden was 16 mm (range 7-35). The overall number of procedures was 25 (mean 1.5 procedures/patient). Of the 17 patients, 15 (88.2%) were rendered stone free. The results of our study have shown that F-URS with the holmium laser is an efficient minimal invasive procedure for treating HSK stones.