Suction-Assisted Miniaturized Percutaneous Nephrolithotomy Outcomes in Anomalous Kidneys: A Multicenter Prospective Study—An EAU-Endourology Collaboration

BACKGROUND: Renal stones in anomalous kidneys pose surgical challenges due to altered anatomy. Miniaturized percutaneous nephrolithotomy (mini-PCNL) reduces morbidity, but concerns remain about stone-free rates (SFRs) and infection. Suction-assisted mini-PCNL (SM-PCNL) enhances fragment removal and controls intrarenal pressure, but its role in anomalous kidneys is unclear. OBJECTIVE: To evaluate perioperative outcomes of SM-PCNL in anomalous kidneys in a multicenter, real-world study and assess variations based on positioning, lithotripsy modality, and renal anomalies. METHODOLOGY: This prospective study across 15 centers (January-December 2024) included 287 adults undergoing SM-PCNL for renal stones in anomalous kidneys. Patients with normal anatomy, non-suction PCNL, or incomplete data were excluded. SFR was assessed via a 30-day non-contrast CT: 100% stone-free (Grade A), residual fragments ≤4 mm (Grade B), or >4 mm/multiple (Grade C, requiring reintervention). RESULTS: Malrotation (65.5%) was the most common anomaly, followed by duplex systems (25.1%), horseshoe kidneys (8.4%), and ectopic kidneys (1.0%). Median stone size was 1.7 cm. Supine positioning was used in 54.4%. Lithotripsy was performed with holmium laser (50.9%), thulium fiber laser (11.1%), or pneumatic lithotripsy (26.1%). Intraoperative clearance was 95.4%. At 30 days, 93.4% achieved Grade A, 5.6% Grade B, and 1.0% required reintervention. Complications were low; 0.7% had sepsis requiring intensive care unit admission. No transfusions or pleural injuries occurred. CONCLUSION: SM-PCNL using 18F suction sheaths with laser in a single stage achieved 93.4% complete SFR with negligible complications and minimal reintervention.