Urolithiasis in kidneys with abnormal lie, rotation or form

Purpose of review The treatment options in urolithiasis in kidneys with abnormalities of form and location can be challenging due to abnormal anatomy (calyceal and renal orientation), relative immobility interfering with movement of equipment, and abnormal relation with other visceral organs. Recent findings In this review, we focus on the different techniques and results of various treatment modalities. The approach to managing these stones should be individualized. We also allude to the results of a few recent series and emphasize various treatment options. Summary Ultrasound helps in gaining access in ectopic kidneys, in addition to being a diagnostic tool. Computerized tomography is pivotal in helping to decide the management and choosing the method of treatment in anomalous kidneys. Flexible ureteroscopy can be a useful tool in stones less than 2 cm in size with the availability of smaller flexible ureteroscopes and access sheaths. However the surgeon should consider complete 'on table' clearance in these patients as the drainage is likely to be impaired. Ultrasound guided percutaneous approaches for ectopic kidneys should be performed by surgeons well versed with it. Laparoscopic assisted percutaneous nephrolithotomy has shown good clearance rates with minimal morbidity and less likelihood of ancillary procedures. Although adequate fragmentation can be achieved with extracorporeal shock wave lithotripsy, the drainage of fragments might be impaired due to the anatomical abnormalities. The choice of shock wave lithotripsy as a treatment option should be made prudently.