Endourological Management of Renal Stones: A Systematic Review, Bayesian Network Meta-Analysis and Meta-Regression

Objectives: To compare stone-free rates (SFRs), operative times, and transfusion rates of various endoscopic techniques for kidney stone management.

Methods: A systematic review was performed, identifying studies comparing the different endoscopic techniques in patients with renal stones. Studies were grouped by location and size of stones (lower pole, 1-2 cm, and >2 cm). Data were extracted to build a Bayesian network modeling the comparisons. Meta-regression adjusted for variations in stone-free definitions. Odds ratios (OR) with 95% credible intervals were reported.

Results: A total of 40 studies were included for analysis, providing a total population of 6,696 patients. For lower pole stones, both percutaneous nephrolithotomy (PCNL) (OR 2.0[1.2, 3.3]) and mini-PCNL (OR 2.3[1.5, 3.6]) showed increased SFRs when compared to retrograde intrarenal surgery (RIRS), while micro-PCNL exhibited a non-significant difference (OR 0.94[0.39,2.3]). For stones between 1-2cm, mini-PCNL showed an increased SFR (OR 2.5[1.5,4.1]) when compared to RIRS; however, there was no significant difference in SFR among the rest of the interventions when compared to RIRS. For stones larger than 2cm, PCNL, mini-PCNL, and ultramini-PCNL resulted in higher SFRs compared to RIRS.

Conclusion: For 1-2cm upper pole/interpolar stones, percutaneous approaches except mini-PCNL did not achieve superior SFRs compared to RIRS. For >2cm stones and lower pole stones, all percutaneous methods, except micro-PCNL, exhibited higher stone clearance than RIRS.