RESUMO
Background: Stone free rate in upper ureteral stones is not as high. We sought to identify easily accessible risk factors attributing to stones left in the ureteroscopy in the treatment of upper ureteral calculi, and to build a simple and reliable predictive model. Methods: Patients treating only for upper ureteral stones in 2018 were retrospectively analyzed. Correlations between factors and the stone free rate were analyzed using bidirectional stepwise regression, curve fitting and binary logistic regression. Stone shape was judged by the gap between length and width in the two-dimensional section. A predictive nomogram model was built based on those selected variables (P<0.05). The area under the receiver operator characteristic curve (AUC) and calibration curve were used to access its discrimination and calibration. Decision curve analysis (DCA) was conducted to test the clinical usefulness. Results: Totally, 275 patients with 284 stones were enrolled in this research. Bidirectional stepwise regression showed that stone length had a significant effect on stone free, instead of width or burden. Stone shapes were also found playing a big role. Curve fitting showed that quasi-circular stones had a high risk of retropulsion, and eventually led to stone left. Finally, stone length, shape, modality, and the distance of stones to the ureteropelvic junction were enrolled in the model. Among them, the distance of the stone to the ureteropelvic junction showed a noticeable impact on stone left. AUC was 0.803 (95% CI: 0.730-0.876), and the calibration curve showed good calibration of the model (concordance index, 0.792). DCA indicated the model added net benefit to patients. Conclusions: The present predictive model based on those factors, stones length, shape, modality, and distance of the stone to the ureteropelvic junction was easy, reliable and useful.
RESUMO
BACKGROUND: Anti-retropulsive devices are often used to prevent stone migration in the treatment of proximal ureteral calculi. They are helpful. However, in the meantime, they also add extra expenses. This study was carried out to investigate the best criteria for treating proximal ureteral stones with anti-retropulsive devices. METHODS: Data from all patients who underwent ureteroscopic holmium: YAG laser lithotripsy for solitary upper ureteral stones in 2018 were collected. Patients who encountered stone retropulsion during the process of inserting the ureteroscope were excluded. Patients were divided into either group URS or group URS + ARD depending on whether the anti-retropulsive device was used. Then, the stone-free rate, expenses and other criteria were compared between groups according to stone location. Stone-free was defined as no stones present. RESULTS: For stones located ≤ 30 mm from the ureteropelvic junction (UPJ), the stone-free rates for the URS group were 80% and 80% at one day and one month after the operation, respectively. Those for the URS + ARD group were 71.4% and 78.6% at one day and one month, respectively. For stones located 31-90 mm from the UPJ, the stone-free rates were 84.7% and 84.7% for the URS group and 89.6% and 95.5% for the URS + ARD group at one day and one month, respectively. A statistically significant difference occurred at one month. For stones located > 90 mm from the UPJ, the two groups were both stone free. In the URS + ARD group, expenses were higher. In addition, the mean diameter of residual stones derived from stones located at 31-90 mm from the UPJ was statistically smaller, and 4 of 7 residual stones passed spontaneously within one month, which was obviously more than that in other locations and the URS group. Other outcomes, including operation time and postoperative stay, showed no significant difference between the groups. CONCLUSION: Anti-retropulsive devices are indeed helpful, but they might be cost-effective for stones located solely in the middle part of the upper ureter, not for those too close to or far from the ureteropelvic junction.
