This is a single-center, observational study including a retrospective cohort and a prospective validation cohort. The study aims to identify independent risk factors for inflammatory ureteral polyps in patients with ureteral calculi and develop a preoperative predictive model. The retrospective part will analyze clinical and imaging data of patients treated at the First Hospital of Jilin University between 2018 and 2025. The prospective part is currently recruiting participants to validate the model. The primary outcome is the intraoperative diagnosis of inflammatory ureteral polyps.

This is a bicentric bidirectional cohort study; retrospective cohort (n=629) has been fully enrolled, prospective cohort is ongoing consecutive enrollment.

Inclusion Criteria:

• Patients aged 18 years or older undergoing ureteroscopic surgery for ureteral calculi at the First Hospital of Jilin University.
• Complete clinical and imaging data available.

Exclusion Criteria:

• Patients with bilateral ureteral calculi.
• Patients with preoperative nephrostomy or indwelling ureteral stent.
• Patients with a history of ureteral or bladder cancer.
• Patients with congenital ureteral anomalies or previous ureteral surgery.
• Patients with severe coagulation disorders or contraindications to ureteroscopy.
• Patients unable to provide informed consent.

The study population includes adult patients with ureteral calculi who underwent ureteroscopic treatment at the First Hospital of Jilin University. The retrospective cohort includes patients treated between 2018 and 2025, and the prospective cohort is recruiting new patients for validation.