Computed tomography –ultrasonography (US) fusion for percutaneous nephrolithotomy access versus conventional US: A multicentre randomised trial

OBJECTIVE: To assess whether computed tomography-ultrasonography (CT-US) fusion navigation, compared with conventional US guidance, improves first-pass success and related access outcomes in a multicentre randomised trial, as accurate renal access is critical in percutaneous nephrolithotomy (PCNL). PATIENTS AND METHODS: Between March and December 2024, 180 adults with renal stones >2 cm scheduled for PCNL at five centres in China were randomised (1:1, stratified by centre) to CT-US fusion or conventional US guidance. The primary outcome was first-pass success (guidewire in pre-specified target calyx with single capsular traversal). Secondary outcomes included puncture attempts, 24-h haemoglobin drop, major bleeding complications (per-patient composite of transfusion or angiographic embolisation), 30-day stone-free rate (no fragments ≥4 mm on non-contrast CT), overall complications, hospital stay, and surgeon procedural comfort. Analyses were intention-to-treat. RESULTS: First-pass success was higher with CT-US fusion (93.3% vs 78.9%; risk ratio 1.18, 95% confidence interval [CI] 1.05-1.33; risk difference [RD] 14.4%, 95% CI 4.3-24.6%; P = 0.009). Haemoglobin drop was smaller (mean difference -3.45 g/L, 95% CI -6.53 to -0.37 g/L; P = 0.028). Major bleeding complications occurred only in the conventional US group (0% vs 6.7%; RD -6.7%, 95% CI -13.8% to -1.2%; P = 0.029; exploratory). Stone-free rates, overall complications, and hospital stay were similar. Procedural comfort was rated higher with CT-US fusion on the 5-point Likert scale (median score 5 vs 3; P < 0.001). CONCLUSIONS: Compared with conventional US guidance, CT-US fusion improved first-pass success during PCNL and was associated with a smaller 24-h haemoglobin drop without compromising efficacy. Further studies are needed to evaluate rare major bleeding events.