Prospective, Randomized Trial Comparing Soft and Firm Ureteral Stents

Soft Vs. Firm Ureteral Stents: Symptoms Improvement Without Affecting Outcomes- a Prospective, Randomized Trial

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 Overview

• Status: Completed
• Conditions: Urolithiasis
• Intervention / Treatment: Device: Soft silicone ureteral stent insertion; Device: firm silicone stent insertion

Detailed Description

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.

• Study Type: Interventional
• Enrollment (Actual): 120
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Israel
  • Hamerkaz
    • Ramat Gan, Hamerkaz, Israel, 5262000
      • Sheba Medical Center

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• patients aged over 18 years
• ureteral stones measuring up to 2cm requiring URS and laser lithotripsy

Exclusion Criteria:

• pediatric patients
• bilateral stones requiring bilateral URS and laser lithotripsy,
• stone located in the renal pelvis or calyces,
• intra-operative complications of any kind,
• any residual stones during the procedure,
• ureteroscopies in which no stones were treated ("white ureteroscopy").

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Triple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Soft silicone stent arm; Patients who recieved soft silicone ureteral stent (Universa, Cook medical) at the end of the ureteroscopy	Device: Soft silicone ureteral stent insertion; Soft silicone ureteral stent insertion; Other Names: Universa
Experimental: Firm silicone stent arm; Patients who recieved firm silicone ureteral stent (percuflex plux, boston scientificl) at the end of the ureteroscopy	Device: firm silicone stent insertion; Insertion of firm silicon ureteral stent (Percuflex Plus); Other Names: percuflex plus

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
the Ureteral stent symptoms questionnaire (USSQ )index score	The summation of the Ureteral stent symptoms questionnaire (USSQ) individual question scores. The questionnaire includes 32 questions, with a scale of zero to five points each. The USSQ Index score represents the summation of each indivisual question score, with a scale of 0-160, with higher score means the patients is suffering from more severe symptoms.	14 days after stent insertion

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Ureteral stent symptoms questionnaire (USSQ) urinary domain score	There are total of 5 different domains in the Ureteral stent symptoms questionnaire (USSQ): urinary synptoms, pain, general health, occupational and sexual distress. The summation of the score of each domain represents a secondary outcome. The urinary domain has 10 questions, each in a scale of zero to five, to a total of 0-50. Higher score means the patient experience more severe urinary symptoms.	14 days after stent insertion
Ureteral stent symptoms questionnaire (USSQ) pain domain score	There are total of 5 different domains in the Ureteral stent symptoms questionnaire (USSQ): urinary synptoms, pain, general health, occupational and sexual distress. The summation of the score of each domain represents a secondary outcome. The pain domain has 7 questions, each in a scale of zero to five, to a total of 0-35. Higher score means the patient experience more severe pain.	14 days after stent insertion
Ureteral stent symptoms questionnaire (USSQ) general health domain score	There are total of 5 different domains in the Ureteral stent symptoms questionnaire (USSQ): urinary synptoms, pain, general health, occupational and sexual distress. The summation of the score of each domain represents a secondary outcome. The general health domain has 6 questions, each in a scale of zero to five, to a total of 0-30. Higher score means the stent affecting the patients general health in a more prominent way.	14 days after stent insertion
Ureteral stent symptoms questionnaire (USSQ) work performance domain score	There are total of 5 different domains in the Ureteral stent symptoms questionnaire (USSQ): urinary synptoms, pain, general health, occupational and sexual distress. The summation of the score of each domain represents a secondary outcome. The work performance domain has 6 questions, each in a scale of zero to five, to a total of 0-30. Higher score means the stent affecting the patients work performance in a more prominent way.	14 days after stent insertion
Ureteral stent symptoms questionnaire (USSQ) sexual performance domain score	There are total of 5 different domains in the Ureteral stent symptoms questionnaire (USSQ): urinary synptoms, pain, general health, occupational and sexual distress. The summation of the score of each domain represents a secondary outcome. The sexual performance domain has three questions, each in a scale of zero to five, to a total of 0-15. Higher score means the stent affecting the patients sexual performance in a more prominent way.	14 days after stent insertion

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Intraoperative lenght	Surgery lenght from the introduction of the ureteroscope to the completion of the stent placment. Measured in minutes.	Upon data collection, at the day of the surgery
Postoperative complications	Postoperative complications reported according to the Clavien-Dindo classification), from the end of the surgery and until 30 days post discharge	30 days post discharge
Hospitalization length	The total amount of days the patient was hospitalized after the procedure. measured in days.	From hospitalization day until discharge days, collected upon patients' discharge, on average of 1 day
Emergency department visits	Total number of emergency department (ED) visits for each patient, wheter they were hospitalized or discharged following that visit.	From discharge day to 30 days post discharge
Number of Re-hospitalizations	Total amount of re-hopitalization number after the original discharge after the surgery, and until 30 days post discharge.	From surgery discharge day to 30 days post discharge

Collaborators and Investigators

• Sponsor: Sheba Medical Center
• Investigators: Study Director: Nir Kleinmann, M.D., Sheba Medical Center, Tel-Hashomer

Study record dates

Study Major Dates

• Study Start (Actual): July 9, 2023
• Primary Completion (Actual): September 10, 2024
• Study Completion (Actual): September 10, 2024

Study Registration Dates

• First Submitted: December 15, 2024
• First Submitted That Met QC Criteria: December 24, 2024
• First Posted (Actual): March 25, 2025

Study Record Updates

• Last Update Posted (Actual): March 25, 2025
• Last Update Submitted That Met QC Criteria: December 24, 2024
• Last Verified: December 1, 2024

More Information

Terms related to this study

• Keywords: Urolithiasis; stent-symptoms
• Additional Relevant MeSH Terms: Urogenital Diseases; Male Urogenital Diseases; Calculi; Pathological Conditions, Anatomical; Urologic Diseases; Female Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Urinary Calculi; Urolithiasis
• Other Study ID Numbers: 0119-23-SMC

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: Upon reasonable request, an anonimized version will be shared
• IPD Sharing Time Frame: Information will be available after the study will be published, for 2 years
• IPD Sharing Access Criteria: Upon request to the primary investigator, an anonimized excel sheath will be sent
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP; ICF; CSR

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: Yes
• product manufactured in and exported from the U.S.: Yes