Flexible ureterorenoscopy (RIRS) vs. Mini- percutaneous nephrolithotomy (MINI-PCNL) for renal stones 20–30 mm a prospective randomized study

Abstract
Background
To evaluate the safety and efficacy of mini percutaneous nephrolithotomy (mini PCNL) and retrograde intrarenal surgery (RIRS) in treatment of kidney stones 20–30 mm.

Methods
A prospective randomized study of 70 patients who presented to the urology department with calyceal or renal pelvic stone of 20–30 mm between September 2017 and September 2019. Patients were randomly divided into two groups, Group A (Mini PCNL) consists of 35 patients who were treated with mini PCNL and Group B (RIRS) consists of 35 patients who were Achieving success of the technique was considered when the patient is stone-free or has radiologically insignificant residual fragments < 4 mm.

Results
The demographic data in this study were comparable in both groups. The stone size was 20.43 ± 2.2 mm in group A & 20.5 ± 2.1 in group B, with no statistical significance. Meanwhile, the operative time in group A was 59.71 ± 19.44 min and in group B was 80.43 ± 14.79 min with statistical significance difference (p value < 0.001), while Fluoroscopy time had a mean of 8.11 ± 2.05 min in group A & 5.8 ± 1.98 min in group B with statistically significant diffrence (p value < 0.001). The stone free rate (SFR) was 88.6% in mini PCNL and 82.9% in RIRS with no statistically significant difference (p value: 0.5).

Conclusion
RIRS and mini PCNL can be an effective and alternative option for treatment of renal stones 2–3 cm. Both techniques have relatively similar SFR but RIRS showed more operative time, on contrary Mini-PCNL has more operative and postoperative complications. A multicenter studies with larger numbers of patients will be more effective to confirm these results.