[Laparoscopic pyelolithotomy in a horseshoe kidney].

A 66-year-old woman had a 22 mm right kidney stone accompanied with a horseshoe kidney. The size of this stone had been increasing gradually from 7 mm to 22 mm during the past 5 years. Although apparent pelviuretic junction stenosis could not be identified by intravenous urography, external pelvis was dilated in both kidneys. Complete excretion of fragmented stones by extracorporeal shockwave lithotripsy seemed to be difficult because impaired urinary passage from the renal pelvis to the ureter was suspected. Percutaneous nephrolithotomy was also difficult due to malrotation of the pelvic-caliceal system and possible interposition of bowel loops between kidney and abdominal wall. Therefore, we chose laparoscopic pyelolithotomy. This procedure made it possible to remove the stone completely with minimum invasiveness. We assume that laparoscopic pyelolithotomy is a safe and effective approach for renal pelvic stone in case of horseshoe kidney.