A comparison among RIRS and MiniPerc for renal stones between 10 and 20 mm using thulium fiber laser (Fiber Dust): a randomized controlled trial.

PURPOSE

We performed a prospective randomized comparison among Retrograde IntraRenal Surgery (RIRS) and MiniPerc (MP) for stones between 10 and 20 mm to evaluate outcomes with the same laser device: Fiber Dust.

METHODS

Patients with a single renal stone between 10 and 20 mm were randomized to RIRS (Group A) versus MP (Group B). Exclusion criteria were age < 18 or > 75, presence of acute infection, coagulation impairments, cardiovascular or pulmonary comorbidities. In both groups, the Fiber Dust laser was used. A CT scan after 3 months was performed. A negative CT scan or asymptomatic patients with stone fragments < 3 mm and a negative urinary culture were the criteria to assess the stone-free status. A statistical analysis was carried out to assess success, complication and retreatment rates and need for auxiliary treatments.

RESULTS

Between January 2021 and January 2022, 186 patients were enrolled (90 in Group A and 96 in Group B). Mean stone size was 15.8 mm and 14.9 mm in Group A and B, respectively (p = 0.23). The overall stone-free rate (SFR) was 73.3% for Group A and 84.4% for Group B. A higher SFR was reached for upper calyceal stones in Group A (90.4%) lower calyceal stones in Group B (91.6%). Retreatment rate (p = 0.31) and auxiliary procedure rate (p = 0.18) were comparable. Complication rate was 5.5% and 5.2% for Groups A and B, respectively.

CONCLUSIONS

RIRS and MP are both effective to obtain a postoperative SFR with Fiber Dust. According to the stone position one treatment is superior to the other one.