Although ureteroscopic treatment is planned, the possibility of percutaneous nephrolithotomy and/or laparoscopy should always be considered. Therefore, before embarking on the ureteroscopic treatment of horseshoe, pelvic, or malrotated kidneys, a CT scan of the abdomen is prudent. This allows for the examination of not only the kidney and the orientation of its calyces but also of the adjacent structures, including the colon. The patient should be made aware that if at the time of surgery it is determined that a ureteroscopic approach is not feasible, then an alternative approach (percutaneous) will be used at the same setting.

Once a guide wire is placed into the kidney a ureteral access sheath should be introduced. This will not only help with irrigation and drainage of the renal pelvis, but it will also straighten the ureter and facilitate the repeat passage of the flexible ureteroscope. Once the stone is identified and if it is small, it should be removed with a nitinol basket. However, if the stone is larger it should be moved into an upper pole calyx for fragmentation with a holmium laser. Due to the poor drainage of these kidneys, every effort should be made to remove all stone fragments, as residual fragments will increase the risk of recurrence of stones in the future. Finally, once all the stone fragments have been removed, a ureteral stent should be placed for a period of approximately 3–7 days.

A full metabolic analysis should be completed in these patients. Most will be found to have at least one metabolic anomaly [13]. As well, prevention is paramount in this population to minimize recurrences and prevent growth of residual fragments.