Efficacy of Negative Pressure Suction-Assisted Flexible Ureteroscopy for Upper Urinary Tract Calculi and Construction of a Stone-Free Rate Prediction Model.

This study retrospectively analyzed 92 patients who underwent negative-pressure suction sheath-assisted flexible ureteroscopic lithotripsy (observation group) and 85 patients who underwent conventional flexible ureteroscopic lithotripsy (control group). Propensity score full matching and weighted analyses were used to balance covariates. Operative time, hospital stay, pain scores, hemoglobin changes, white blood cell counts, neutrophil counts, stone clearance rates, and complications were compared, and predictive models for stone clearance were constructed. The observation group achieved significantly higher stone-free rates at 3 days (69.6% vs. 29.7%, p < 0.001) and 1 month (75.0% vs. 34.2%, p < 0.001) postoperatively. Relative to the control group, the observation group had postoperative white blood cell counts closer to normal values (9.25 ± 3.26 vs. 10.08 ± 3.78, p < 0.05), with a smaller increase from baseline (0.82 ± 4.90 vs. 2.96 ± 5.02, p < 0.05). The neutrophil percentage was also lower (0.73 ± 0.10 vs. 0.77 ± 0.07, p < 0.05), and visual analogue scale pain score was significantly reduced (2.00 ± 0.53 vs. 2.56 ± 0.89, p < 0.001). The predictive models achieved areas under the receiver operating characteristic curve of 0.727 (95% confidence interval: 0.616-0.839) at 3 days and 0.742 (95% confidence interval: 0.630-0.855) at 1 month postoperatively, indicating good discriminatory ability. This study shows that flexible negative-pressure suction sheath-assisted flexible ureteroscopic lithotripsy improves short- and mid-term stone clearance rates in patients with upper urinary tract stones. The models perform well and may facilitate individualized clinical decision-making.