A Multicenter, Randomized Controlled Trial Comparing the Retrograde Intrarenal Surgery With a Tip-Flexible Suction Access Sheath to the Standard Percutaneous Nephrolithotomy for the Treatment of 2-3 cm Unilateral Renal Stones

Kidney stones (renal calculi) are a common urological condition that can lead to pain, infection, and renal dysfunction. For renal stones measuring 2-3 cm, both retrograde intrarenal surgery (RIRS) and percutaneous nephrolithotomy (PCNL) are recognized treatment options. Traditional RIRS is less invasive but may be associated with lower stone-free rates for larger stones. A newly developed tip-flexible suction access sheath (TFS-UAS) allows improved access to renal calyces, reduces intrarenal pressure, and enables efficient stone fragment evacuation through continuous suction.

This study is a prospective, multicenter, randomized controlled trial designed to compare the effectiveness and safety of RIRS using the TFS-UAS versus standard PCNL in patients with unilateral renal stones measuring 2-3 cm. A total of 308 patients aged 18-80 years will be enrolled from four tertiary hospitals in China. Eligible participants will be randomized into two groups to receive either TFS-UAS-assisted RIRS or standard PCNL. The primary endpoint is the stone-free rate (SFR) at 3 months, assessed by CT scan. Secondary outcomes include postoperative infection rates, changes in hemoglobin and procalcitonin levels, hospital stay duration, and pain scores.

This study aims to provide high-quality evidence to guide surgical decision-making in the management of medium-sized kidney stones and to evaluate the potential advantages of the new suction-assisted sheath in minimally invasive endourology.