Prospective, Randomized Trial Comparing Soft and Firm Ureteral Stents

Overview

The goal of this clinical trial is to evaluate whether ureteral stent type impacts stent-related symptoms and quality of life in patients undergoing ureteroscopy (URS) and stone lithotripsy for ureteral stones. The main questions it aims to answer are: * Does a soft polymer stent reduce stent-related symptoms compared to a firm polymer stent? * Does stent type affect intra- and postoperative complications? Researchers will compare patients receiving a soft polymer stent (Universa®, Cook Medical) to those receiving a firm polymer stent (Percuflex®, Boston Scientific) to determine if soft stents improve patient comfort and quality of life while maintaining a similar safety profile. Participants will: * Undergo URS and stone lithotripsy for ureteral stones. * Be randomly assigned to receive either a soft or firm ureteral stent. * Complete the Ureteral Stent Symptoms Questionnaire (USSQ) upon stent removal, 14 days after URS.

Study Design and Patient Selection 1. Study Period and Ethical Approval: * Conducted between July 2023 and July 2024 following institutional review board approval (SMC 0119-23). * Informed consent obtained from all participants. * Adhered to the Declaration of Helsinki. 2. Stent Types and Randomization: * Soft stent: Universa® (Cook Medical). * Firm stent: Percuflex™ Plus (Boston Scientific). * Randomization in a 1:1 ratio using asymptomatic maximal randomization. Surgical Technique and Intervention Operative Team included three fellowship-trained endourologists. Procedure Details: * Ureteroscopy performed using standard 6.5/8.5Fr semi-rigid ureteroscope. * Lithotripsy performed using a 120W Holmium:YAG laser (0.3 Joule, 40 Hertz, dusting technique). Stent Placement was performed using a 0.038 Inch glide wire. 6Fr stents used, either soft or firm polymer material, according to randomization. Proximal stent curls positioned in the upper calyx/renal pelvis; distal curls in the bladder. Postoperative Care Stent removal was scheduled 2 weeks post-procedure, ans performed using a flexible cystoscope in the outpatient clinic. Symptoms assesed using the Ureteral Stent Symptoms Questionnaire (USSQ) that was completed at the stent removal visit. Statistical Analysis 1. Sample Size Calculation: * Based on a 3-point difference in USSQ index score between groups. * Assumed 5% type I error and 80% power. * Adjusted for a 10% dropout rate; target sample size: 140 patients. 2. Data Blinding: * Patients, data collectors, and analysts blinded to allocation. * Since blinding the surgeons to stent type was impossible, surgeons were not involved in data collection or analysis. 3. Analysis Methods: * Continuous variables: Mann-Whitney U test; median and IQR. * Categorical variables: Pearson's chi-square or Fisher's exact test; frequencies and proportions. * Multivariate linear regression for USSQ index and urinary domain scores. * Statistical significance set at p\<0.05. * Analyses conducted using IBM SPSS v26. This protocol ensures a rigorous and reproducible methodology for evaluating the impact of stent type on patient-reported outcomes following ureteroscopy and lithotripsy.