Stone extraction during flexible ureterorenoscopy with or without the hydrogel method: a randomized, multicenter...

Area of Science:

• Urology
• Minimally Invasive Surgery
• Nephrolithiasis Management

Background:

• Standard flexible ureterorenoscopy (fURS) often fails to remove all small kidney stone fragments, increasing recurrence risk.
• The mediNiK® hydrogel method was developed to embed and extract minute fragments during fURS.
• Improving stone-free rates is crucial in kidney stone surgery.

Purpose of the Study:

• To evaluate the safety and feasibility of the hydrogel method for stone fragment extraction during fURS.
• To determine if the hydrogel method improves the retrieval of fragments smaller than 1 mm.

Main Methods:

• Prospective, randomized, multicenter trial involving patients with kidney stones >8 mm.
• Patients were randomized to fURS with hydrogel (Group 1) or fURS alone (Group 2).
• Fragment retrieval was assessed post-laser lithotripsy, categorized by size, and adverse events were monitored.

Main Results:

• The hydrogel group (Group 1) retrieved significantly more fragments <1 mm (1716 vs. 209) and >1 mm (310 vs. 118) compared to Group 2.
• Per-patient analysis showed more <1 mm fragments removed in Group 1 (median 7 vs. 0, p<0.003).
• Surgery duration was longer in Group 1 (80 min vs. 62 min, p=0.02), with no serious adverse events reported.

Conclusions:

• The hydrogel method is a safe and feasible adjunct to fURS for enhanced stone fragment retrieval.
• Improved extraction of small fragments (<1 mm) was demonstrated with the hydrogel method.
• Larger studies are needed to assess long-term stone-free rates and recurrence due to small sample size.