Active treatment of renal stones in pelvic ectopic kidney: systematic review of literature.

Introduction: Chronic obstruction and stones formation are common in pelvic ectopic kidney (PEK), and stone treatment in such conditions can be challenging. Aim of this systematic review was to examine all the available active treatment modalities for PEK stones in order to critically appraise their advantages and limitations.

Evidence acquisition: A search on Medline, Embase, and the Cochrane Library databases was performed to identify literature focused on the active treatment of PEK stones. Original articles, case report and case series were included in the search. The systematic review was conducted in accordance to the PRISMA checklist. The study period went from inception of databases to October 2019.

Evidence synthesis: Of the 256 articles identified, 23 met the inclusion criteria. 334 patients were included in the studies and 119 had stones in PEK. Five patients were treated with SWL, 40 with ureterorenoscopy, 37 with percutaneous nephrolithotomy both by ultrasound/X-Ray or lap-assisted puncture, and 37 with minimally invasive laparoscopic or robot assisted pyelolithotomy. Overall, stone free rate after first treatment was higher in minimally invasive laparoscopic or robot assisted pyelolithotomy (97.2%) compared to percutaneous nephrolithotomy (84.96%) and ureterorenoscopy studies (65.94%). The higher complication rate was reported in percutaneous nephrolithotomy not lap-assisted (33.3%).

Conclusions: The choice of the approach depends on different factors such as stone size, density and location in accordance with upper urinary tract alterations, kidney anatomy and operator experience. The choice of a retrograde, percutaneous or lap/robot approach should be carefully selected evaluating upper urinary tract anatomy and stone features.