Systematic Review and Meta-Analysis Comparing Percutaneous Nephrolithotomy, Retrograde Intrarenal Surgery and Shock Wave Lithotripsy for Lower Pole Renal Stones Less Than 2 cm in Maximum Diameter

Purpose: The aim of the current systematic review and meta-analysis is to provide an answer on which is the most appropriate approach for the management of the lower pole stones with a maximal dimension of 2 cm or less. Materials and Methods: A systematic review was conducted on PubMed (R), SCOPUS (R), Cochrane and EMBASE (R). The PRISMA guidelines and the recommendations of the EAU Guidelines office were followed. Retrograde intrarenal surgery, shock wave lithotripsy and percutaneous nephrolithotomy were considered for comparison. The primary end point was the stone-free rate. Results: A total of 15 randomized controlled trials were eligible. Percutaneous nephrolithotripsy and retrograde intrarenal surgery have higher stone-free rates in comparison to shock wave lithotripsy and require fewer re-treatment sessions. Operative time and complications seem to favor shock wave lithotripsy in comparison to percutaneous nephrolithotripsy, but this takes place at the expense of multiple shock wave lithotripsy sessions. Retrograde intrarenal surgery seems to be the most efficient approach for the management of stones up to 1 cm in the lower pole. Conclusions: The pooled analysis of the eligible studies showed that the management of lower pole stones should probably be percutaneous nephrolithotripsy or retrograde intrarenal surgery to achieve stone-free status over a short period and minimal number of sessions. For stones smaller than 10 mm, retrograde intrarenal surgery is more efficient in comparison to shock wave lithotripsy. The decision between the 2 approaches (percutaneous nephrolithotripsy or retrograde intrarenal surgery) should be individual, based on the anatomical parameters, the comorbidity and the preferences of each patient.