Repeat Imaging to Avoid Surgery: An Initiative to Reduce-Negative Ureteroscopy in Patients with Ureteral Stones

Objective: Negative ureteroscopy (nURS) describes the absence of ureteric stones during endoscopic visualization, despite imaging confirmation before surgery. This study aimed to identify the prevalence of, and factors predicting nURS in patients presenting with ureteral stones. Materials and Methods: We performed a retrospective review of all uretersocopies for ureteral stones performed by three endourologists over a six-month periods. Only patients without previous intervention for the stone in question were considered for this study. nURS was investigated in relation to demographics, time from imaging to procedure, stone and procedure-specific characteristics, etc. Statistical analysis consisted of descriptive statistics and univariate and multivariate logistic regression analyses using SPSS statistical software. Results: Eighty-two patients were reviewed, with 14.6% of those patients experiencing a nURS. The frequency of computed tomography imaging and time from imaging to procedure did not differ significantly between +URS and nURS. Stone size (7.74 +/- 3.09 vs 6.73 +/- 2.28 mm; p=0.298), and stone location (68.6% vs 75.0% distal; p=0.686) were also not significantly different. Significantly more nURS procedures were performed in the emergency (21.7% vs 50.0%; p=0.048). These emergency nURS patients also had a statistically significant shorter duration from imaging to URS (7.1 vs 20.7 days; p=0.001). nURS procedures were 3.60 times more likely to be performed as an emergency (odds ratio=3.60; 95% confidence interval=1.01-12.79; p=0.048). Conclusion: We have identified 14% of patients undergoing ureteroscopy for ureteral stones at our center are being overtreated. Therefore, we believe that it is imperative that reimaging be considered in this patient population before surgery.