Aim: The aim of this study was to evaluate the patient-, stone-, and anatomy-related factors that may influence the impaction status of proximal ureteral stones, with a particular focus on the ureteral wall thickness (UWT) as a radiologic surrogate marker of chronic irritation. Materials and Methods: A total of 115 adult patients who underwent ureteroscopic treatment for impacted proximal ureteral stones between January 2021 and December 2023 were retrospectively analyzed. The demographic data, comorbidities, stone characteristics (volume, location, and HU value), and anatomical parameters (hydronephrosis grade, proximal ureteral diameter, and UWT) were evaluated using non-contrast computed tomography (NCCT). The correlations between the UWT and both patient- and stone-related variables were assessed using linear and logistic regression analyses. Results: The mean patient age was 45.3 ± 13.8 years, with a male-to-female ratio of 2.11. A significant positive correlation was observed between the UWT and hydronephrosis grade (p = 0.002), presence of comorbidities such as hypertension or diabetes mellitus (p = 0.005), and stone volume (p = 0.005). A larger stone diameter and length were also significantly associated with increased UWT (p = 0.014 and p = 0.005, respectively). However, no statistically significant correlation was found between the UWT and stone density (p = 0.614) or the duration of stone presence (p = 0.987). Conclusions: Increased ureteral wall thickness appears to be a strong indicator of stone impaction severity and is positively associated with hydronephrosis, comorbid conditions, and stone size. These findings support the potential clinical utility of UWT in preoperative planning and treatment selection for impacted upper ureteral stones. Further prospective studies are warranted to validate these observations and explore their implications for procedural success and complication risk.

Aim: This study aimed to evaluate the potential impact of stone characteristics, patient factors, and upper tract anatomical parameters in the prediction of residual fragments (RFs) following the flexible ureteroscopic (fURS) management of renal stones. Patients and Methods: Between June 2023 and July 2024, a total of 104 cases underwent fURS for the minimally invasive management of medium-sized renal stones (10–25 mm), and 28 cases presenting with RFs 3 months after these procedures were included for further evaluation. In addition to the assessment of patient-related factors, non-contrast computed tomography (NCCT) was performed in all cases in an attempt to assess specific stone characteristics and upper tract anatomical parameters in detail during the 3-month follow-up period. Results: An evaluation of our findings indicated that, among the evaluated parameters, a higher degree of hydronephrosis (>Grade 2), a larger stone size (>15 mm), and the presence of multiple stones were found to affect the presence of RFs significantly (p = 0.020, p = 0.012, and p = 0.040, respectively). On the other hand, although the analysis of other parameters such as patient gender, stone side, stone hardness, and the use of an access sheath with univariate regression demonstrated potential correlations, none of these parameters demonstrated a significant impact when analyzed using backward logistic regression. Logistic regression revealed that Grade 2 hydronephrosis (OR = 18.3, p = 0.020), stone size > 15 mm (OR = 7.0, p = 0.012), and multiple stones (OR = 3.7, p = 0.040) significantly increased the risk of residual fragments following fURS. Conclusions: In light of our findings and published data, we can conclude that endourologists should consider the likelihood of RFs’ presence after successful stone disintegration with fURS. A detailed evaluation of the relevant factors revealed that patients with larger stones, higher degrees of hydronephrosis, and multiple calculi may carry the risk of residual fragments after these procedures. Thus, the utilization of such reliable predictive parameters may aid in selecting optimal stone removal strategies and planning subsequent interventions in the rational management of RFs.