NTrap in Prevention of Stone Migration During Ureteroscopic Lithotripsy for Proximal Ureteral Stones: A Meta-Analysis

Purpose: To evaluate the effectiveness of NTrap in the prevention of stone migration during ureteroscopic lithotripsy for proximal ureteral stones. Methods: Eligible studies were identified from electronic databases (PubMed, Embase, the Cochrane Library, ISI - Science Citation Index, and Chinese biomedicine literature database). The database search, quality assessment, and data extraction were independently performed by two reviewers. Our primary outcomes were the stone-free (SF) and incidence of stone migration. Secondary outcomes were operative time and the rate of auxiliary procedures. The outcomes were explored by using Review Manager 5.0. Sensitivity analysis was performed to explore the influence of low-quality studies. Results: Two randomized controlled trials and one case-control study including 456 patients met the inclusion criteria. Meta-analysis of extractable data showed that patients who underwent ureteroscopic lithotripsy with the use of the NTrap demonstrated a significant advantage over without the use of the NTrap in terms of the stone-free rate (odds ratio [OR] = 3.08, 95% confidence interval [CI] [1.45-6.53], P = 0.003); the incidence of stone migration was significantly lower in NTrap treatment than without NTrap (OR = 0.23, 95% CI: 0.10-0.53, P = 0.0006, while there was no significant difference in operative time between NTrap and control (mean difference = -3.25, 95% CI: -16.11-9.62, P = 0.62). Our pooled meta-analysis showed that the incidence of auxiliary shockwave lithotripsy was significantly lower in NTrap treatment than control (OR = 0.29, 95% CI: 0.12-0.70, P = 0.006). Conclusion: The results of this meta-analysis suggested that the NTrap stone occlusion device is efficient at preventing stone retropulsion during ureteroscopic lithotripsy of proximal ureteral calculi. The findings of this review highlight the need for more efficient performance of higher quality, more rigorous, large sample, long-term randomized controlled trials where outcomes are detailed in description.