Presented by: Ukrit Rompsaithong MD
Division of Urology, Department of Surgery, Khon Kaen University, Khon Kaen, Thailand

Introduction

Negative ureteroscopy (URS), characterized by the unexpected absence of detecting stones during surgery, is an uncommon but known outcome in the management of ureteral stones. This outcome potentially exposes patients to unnecessary surgical interventions and complications. However, these risks should be weighed against the risk of leaving ureteral stone untreated. This study aims to identify predictive factors associated with negative URS and propose solutions to improve stone detection rates.

Materials

In this cohort study, we retrospectively analyzed prospectively collected data on consecutive patients who underwent URS for unilateral ureteral stone disease from the Registry for Stones of the Kidney and Ureter (ReSKU) between 2015 and 2022. Exclusion criteria included concomitant kidney stone procedures, and staged procedures. Patient characteristics, preoperative imaging, operative data, and complications were compared between positive and negative URS cases. Univariable and multivariable logistic regression analyses identified factors associated with negative URS. 

Results

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A total of 307 renal units were included, with a negative URS rate of 12.1% (95%CI 8.6-16.2%). Negative URS cases had significantly shorter operative times compared to URS cases where stones were found (39 vs 51 minutes, p < 0.001) and a lower frequency of postoperative stent placement (43.2% vs 80.4%, p < 0.001). No significant differences were observed in the length of hospital stay and complication rate between the two groups. Factors significantly associated with negative URS were absence of microscopic hematuria (OR 30.62), ureterovesical junction stone location (OR 28.54), stone size <6 mm (OR 16.53), interval symptomatic presentation (OR 13.50), interval since computed tomography (CT) scan >2 months (OR 7.54), and right-side stone location (OR 5.62) (Table 1).

Conclusion

Optimizing preoperative imaging protocols and careful patient selection can help reduce negative URS rates. Patients should be counseled about the risk of a negative ureteroscopy and repeat imaging should be considered when these associated factors are present.

Funding

None

Lead Authors

Thomas Chi, MD
Department of Urology, University of California, San Francisco, San Francisco, California

Co-Authors

Wilson Sui, MD
Department of Urology, University of California, San Francisco, San Francisco, California

Heiko Yang, MD
Department of Urology, University of California, San Francisco, San Francisco, California

David Bayne, MD
Department of Urology, University of California, San Francisco, San Francisco, California

Justin Ahn, MD
Department of Urology, University of California, San Francisco, San Francisco, California

Marshall Stoller, MD
Department of Urology, University of California, San Francisco, San Francisco, California