Could retrograde intrarenal surgery be a safe and effective alternative to mini-percutaneous nephrolithotomy ın the management of relatively large (20-30 mm) stones? A critical evaluation

Purpose: To compare the outcomes of mini-percutaneous nephrolithotomy (mPCNL) and retrograde intrarenal surgery (RIRS) in patients with renal stones sizing 2-3 cm.

Methods: A total of 566 patients from 6 institutions who underwent mPCNL (n = 440) and RIRS (n = 126) procedures were enrolled in our study. The retrospective patient cohort was reviewed and compared. Binary logistic regression analysis was performed to determine factors predicting success in the RIRS group.

Results: The stone-free rates were 91.1 and 77% for the mPCNL and RIRS groups, respectively (p < 0.001). The auxiliary procedure rates were 4.5 and 39.7% in the mPCNL and RIRS groups, respectively (p < 0.001). Mean values of hemoglobin decrease, fluoroscopy time, and hospitalization time were significantly higher in the mPCNL group (p < 0.001). While the Clavien grade 1-2 complication rates were 10.9 and 34.1% (p < 0.001) in two groups, these values were 2.7 and 1.6% (p = 0.539), respectively, for Clavien grade 3-4 complication rates. Although three patients in the mPCNL group received blood transfusions, none of the patients in the RIRS groups were transfused. The stone location and stone density parameters were found to be the independent predictive factors for RIRS success.

Conclusions: mPCNL provided a higher stone-free rate, less need for the auxiliary procedure, and lower complication rates compared to RIRS in patients with 2-3 cm stones. Blood loss, radiation exposure, and a hospital stay of mPCNL can be significantly reduced with the RIRS technique in selected patients.