Suction Mini-PCNL Versus Standard PCNL for the Management of 2-4cm Kidney Stones

Percutaneous nephrolithotomy (PCNL) is recommended as the first-line treatment choice for kidney stones larger than 2cm in international guidelines . However, tract-related complications affecting renal parenchymal and blood vessels have always been a concern . The mini-PCNL technique which uses a smaller tract (≤18 Fr) has been introduced to decrease tract-related complications . Nevertheless, the smaller mini-PCNL tract necessitates fragmentationi of stones into smaller pieces before extraction, potentially prolonging the operative time. Additionally, higher pressure irrigation is often required to flush out fragments by vacuum cleaner effect. If the drainage of irrigation fluid is insufficient via a smaller tract, the intrarenal pressure (IRP) may build up, leading to pyelovenous backflow and infectious complications. Suction application in mini-PCNL has the potential to enhance stone fragments removal efficiency, maintain low IRP, and decrease potential postoperative infection complications. In the pre-suction era, mini-PCNL achieved noninferior stone-free rates (SFR) and operative times compared to standard PCNL, along with benefits of reduced bleeding, less postoperative pain, and shorter hospital stay. However, high-level evidence regarding whether suction mini-PCNL can attain comparable outcomes to standard PCNL is still lacking. Therefore, we have designed this multicenter, international, randomized controlled noninferiority trial comparing suction mini-PCNL with standard PCNL in the management of 2-4 cm kidney stones.

Inclusion Criteria: 1. Adults aged 18-70 years. 2. American Society of Anesthesiology (ASA) score of 1-2. 3. Kidney stones measuring 2-4 cm in diameter on non-contrast computer tomography. 4. Ability to provide written informed consent and adhere to trial requirements. Exclusion Criteria: 1. Anatomy abnormalities, such as urinary diversion, horseshoe kidney, transplanted kidney, or ureteropelvic junction obstruction. 2. Untreated acute urinary tract infection (UTI). 3. Patients on anticoagulant/antithrombotic therapy, or with uncorrected coagulopathies. 4. Patients who decline trial enrolment or cannot adhere to trial requirements.