Pediatric UrolithiasisNCT07742358
Comparison of Ureteral Stent Designs in Children With Kidney Stones
A study testing Polaris Ultra Ureteral Stent and Cook Double-J Ureteral Stent in people with Pediatric Urolithiasis and Ureteral Stent-Related Symptoms, run by The Hospital for Sick Children at 1 site in Canada.
Trial summary
This study will compare two commonly used ureteral stents in children and adolescents undergoing staged treatment for kidney stones. Ureteral stents are small tubes placed between the kidney and bladder to help urine drain after a procedure. Read more about this study
- Who is it for?
- Ages 8 to 18 years
- Conditions the study is for
- Pediatric Urolithiasis, Ureteral Stent-Related Symptoms
- What is being tested?
- Polaris Ultra Ureteral Stent and Cook Double-J Ureteral Stent
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 20 participants
- Where
- 1 siteCanada
- Study dates
- 1 Sep 2026to 1 Sep 2027
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 8 to 18 years
- All sexes
- No healthy volunteers
- Child, Adult
Who may be able to join
- Ability of the participant and/or legally authorized representative to provide written informed consent, with assent obtained from the participant when appropriate, in accordance with institutional policy.
- Age 8 to 18 years at the time of enrollment.
- Undergoing staged ureteroscopic stone management requiring two sequential ureteral stent placements as part of standard clinical care.
- Planned placement of unilateral ureteral stents with an anticipated indwelling duration of approximately 4 to 6 weeks per stent.
- American Society of Anesthesiologists Physical Status Classification I or II at the time of surgery.
- Ability and willingness of the participant and/or caregiver to comply with study procedures, including completion of symptom assessments and questionnaires at specified time points.
- Ability to complete study questionnaires in English, either independently or with caregiver assistance.
Who cannot join
- American Society of Anesthesiologists Physical Status Classification III or higher at the time of surgery.
- Active urinary tract infection, defined as clinical symptoms consistent with infection and a positive urine culture, at the time of screening or before stent placement.
- Significant baseline bladder dysfunction, including neurogenic bladder, overactive bladder requiring chronic anticholinergic therapy, or prior bladder augmentation, that could confound assessment of stent-related symptoms.
- Requirement for bilateral ureteral stent placement or planned bilateral ureteroscopic procedures.
- Known hypersensitivity or allergy to materials used in either ureteral stent included in the study.
- Pregnancy or lactation, as determined by clinical assessment and/or institutional testing requirements, where applicable.
- Use of chronic opioid therapy, chronic anticholinergic medications, or other medications that, in the investigator's opinion, would substantially interfere with assessment of stent-related pain or urinary symptoms.
- Participation in another interventional clinical trial that could interfere with the objectives or outcome assessments of this study.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Canada1 site, 1 recruiting
- Recruiting
SickKids
Toronto, Ontario, M5G 1E8
Michael Chua, 416-813-7654 ext. 415122, michael.chua@sickkids.ca
About this study
Official title: Randomized Single-Blind Cross-Over Trial Evaluating the Impact of Ureteral Stent Design on Bladder Spasms and Stent-Related Symptoms
This study will compare two commonly used ureteral stents in children and adolescents undergoing staged treatment for kidney stones. Ureteral stents are small tubes placed between the kidney and bladder to help urine drain after a procedure. Although stents are effective, they can cause bladder spasms, pain, urinary urgency, and other uncomfortable symptoms.
Participants aged 8 to 18 years will receive both a standard Cook double-J ureteral stent and a Polaris Ultra ureteral stent during two planned procedures. The order in which the stents are used will be assigned at random, and participants and caregivers will not be told which stent is in place during each treatment period. Participants will report bladder spasms, pain, urinary symptoms, and quality of life through questionnaires and symptom assessments. The study will determine whether differences in stent design affect comfort, bladder spasms, urinary tract infections, or other stent-related complications. Both stents are approved by Health Canada and are used as part of routine clinical care.
- Being tested
- Polaris Ultra Ureteral Stent, Cook Double-J Ureteral Stent
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Polaris Ultra Ureteral StentDevice
The Polaris Ultra ureteral stent is a commercially available, Health Canada-approved double-J ureteral stent used for temporary ureteral drainage after ureteroscopic stone treatment. The stent has a dual-durometer polymer design with a firmer proximal segment and a softer distal bladder segment, as well as a hydrophilic coating. In this study, a 6 French stent of a length appropriate for the participant's anatomy will be placed cystoscopically and will remain in place for approximately 4 to 6 weeks during one treatment period.
Cook Double-J Ureteral StentDevice
The Cook double-J ureteral stent is a commercially available, Health Canada-approved ureteral stent used as the standard-of-care comparator for temporary ureteral drainage after ureteroscopic stone treatment. It is a conventional polyurethane double-J stent with pigtail coils at the renal and bladder ends. In this study, a 6 French stent of a length appropriate for the participant's anatomy will be placed cystoscopically and will remain in place for approximately 4 to 6 weeks during one treatment period.
| Study group | Role | What they receive |
|---|---|---|
| Polaris Ultra Followed by Cook Double-J | Experimental | Participants assigned to this sequence will receive the Polaris Ultra ureteral stent during the first clinically indicated ureteroscopic procedure. At the subsequent staged procedure, the Polaris Ultra stent will be removed and participants will receive the Cook double-J ureteral stent for the second treatment period. Each stent will remain in place for approximately 4 to 6 weeks. Participants will complete symptom, pain, and quality-of-life assessments during both treatment periods. Receives: Device: Polaris Ultra Ureteral Stent; Device: Cook Double-J Ureteral Stent |
| Cook Double-J Followed by Polaris Ultra | Experimental | Participants assigned to this sequence will receive the Cook double-J ureteral stent during the first clinically indicated ureteroscopic procedure. At the subsequent staged procedure, the Cook stent will be removed and participants will receive the Polaris Ultra ureteral stent for the second treatment period. Each stent will remain in place for approximately 4 to 6 weeks. Participants will complete symptom, pain, and quality-of-life assessments during both treatment periods. Receives: Device: Polaris Ultra Ureteral Stent; Device: Cook Double-J Ureteral Stent |
What is being measured
The primary outcome is the main question the study is designed to answer.
Frequency of Bladder Spasm Episodes
Measured: Postoperative Days 1, 3, and 7 during each of two stent treatment periods
Secondary outcomes (3)
Canadian Endourology Group Stent Symptom Score
The Canadian Endourology Group Stent Symptom Score includes several subdomains rather than one clearly stated total range: urinary symptom items generally use 5 response levels, pain intensity uses a 0-10 scale, healthcare-use items are Yes/No, and quality-of-life interference items use 0-10 scales. Across domains, higher values or more severe responses indicate worse symptoms or greater impairment.
Measured: Postoperative Days 1, 3, and 7 after each stent placement, over approximately 8-12 weeks
Stent-Related Pain Intensity Measured Using a Visual Analog Scale
Stent-related pain intensity will be measured using a 0-10 Visual Analog Scale, where 0 means no pain and 10 means the worst pain imaginable; higher scores indicate worse pain.
Measured: Postoperative Days 1, 3, and 7 after each stent placement, over approximately 8-12 weeks
Incidence of Symptomatic Urinary Tract Infection
Measured: During each 4- to 6-week ureteral stent indwelling period
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted3 Aug 2026
- Study start1 Sep 2026 (estimated)
- Primary completion1 Sep 2027 (estimated)
- Study completion1 Sep 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Pediatric UrolithiasisStudies of the same condition, open and under way.
- More trials run by The Hospital for Sick ChildrenThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Crossover
- Model description
- Participants will be randomized in a 1:1 ratio to one of two treatment sequences. One sequence will receive the Polaris Ultra ureteral stent during the first treatment period followed by the Cook double-J ureteral stent during the second period. The other sequence will receive the stents in the reverse order. Each participant will therefore receive both interventions and serve as their own control.
- Masking
- Double blind
- Who is masked
- Participant, Outcomes assessor
- Enrolment
- 20 participants (estimated)
Sponsor and investigators
- Lead sponsor
- The Hospital for Sick Children
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Michael Chua, The Hospital for Sick Children
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07742358
- Sponsor's protocol ID
- 4103
- Status last verified
- Jul 2026
- First submitted
- 27 Jul 2026
- Last updated
- 3 Aug 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 3 Aug 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Randomized Single-Blind Cross-Over Trial Evaluating the Impact of Ureteral Stent Design on Bladder Spasms and Stent-Related Symptoms
- ClinicalTrials.gov ID
- NCT07742358
- Acronym / sponsor ID
- 4103
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 20 participants (estimated)
- Lead sponsor
- The Hospital for Sick ChildrenUniversity, hospital or other
- Study start
- 1 Sep 2026 (estimated)
- Primary completion
- 1 Sep 2027 (estimated)
- Study completion
- 1 Sep 2027 (estimated)
- First posted
- 3 Aug 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This study will compare two commonly used ureteral stents in children and adolescents undergoing staged treatment for kidney stones. Ureteral stents are small tubes placed between the kidney and bladder to help urine drain after a procedure. Although stents are effective, they can cause bladder spasms, pain, urinary urgency, and other uncomfortable symptoms.
Participants aged 8 to 18 years will receive both a standard Cook double-J ureteral stent and a Polaris Ultra ureteral stent during two planned procedures. The order in which the stents are used will be assigned at random, and participants and caregivers will not be told which stent is in place during each treatment period. Participants will report bladder spasms, pain, urinary symptoms, and quality of life through questionnaires and symptom assessments. The study will determine whether differences in stent design affect comfort, bladder spasms, urinary tract infections, or other stent-related complications. Both stents are approved by Health Canada and are used as part of routine clinical care.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Double blind (participant, outcomes assessor)
- Number of arms
- 2
- Model description
- Participants will be randomized in a 1:1 ratio to one of two treatment sequences. One sequence will receive the Polaris Ultra ureteral stent during the first treatment period followed by the Cook double-J ureteral stent during the second period. The other sequence will receive the stents in the reverse order. Each participant will therefore receive both interventions and serve as their own control.
| Arm | Type | Receives |
|---|---|---|
| Polaris Ultra Followed by Cook Double-J | Experimental | Device: Polaris Ultra Ureteral Stent, Device: Cook Double-J Ureteral StentParticipants assigned to this sequence will receive the Polaris Ultra ureteral stent during the first clinically indicated ureteroscopic procedure. At the subsequent staged procedure, the Polaris Ultra stent will be removed and participants will receive the Cook double-J ureteral stent for the second treatment period. Each stent will remain in place for approximately 4 to 6 weeks. Participants will complete symptom, pain, and quality-of-life assessments during both treatment periods. |
| Cook Double-J Followed by Polaris Ultra | Experimental | Device: Polaris Ultra Ureteral Stent, Device: Cook Double-J Ureteral StentParticipants assigned to this sequence will receive the Cook double-J ureteral stent during the first clinically indicated ureteroscopic procedure. At the subsequent staged procedure, the Cook stent will be removed and participants will receive the Polaris Ultra ureteral stent for the second treatment period. Each stent will remain in place for approximately 4 to 6 weeks. Participants will complete symptom, pain, and quality-of-life assessments during both treatment periods. |
Who may qualify
- Ages
- 8 to 18 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult
Key inclusion criteria (7 listed)
- Ability of the participant and/or legally authorized representative to provide written informed consent, with assent obtained from the participant when appropriate, in accordance with institutional policy.
- Age 8 to 18 years at the time of enrollment.
- Undergoing staged ureteroscopic stone management requiring two sequential ureteral stent placements as part of standard clinical care.
- Planned placement of unilateral ureteral stents with an anticipated indwelling duration of approximately 4 to 6 weeks per stent.
- American Society of Anesthesiologists Physical Status Classification I or II at the time of surgery.
Key exclusion criteria (8 listed)
- American Society of Anesthesiologists Physical Status Classification III or higher at the time of surgery.
- Active urinary tract infection, defined as clinical symptoms consistent with infection and a positive urine culture, at the time of screening or before stent placement.
- Significant baseline bladder dysfunction, including neurogenic bladder, overactive bladder requiring chronic anticholinergic therapy, or prior bladder augmentation, that could confound assessment of stent-related symptoms.
- Requirement for bilateral ureteral stent placement or planned bilateral ureteroscopic procedures.
- Known hypersensitivity or allergy to materials used in either ureteral stent included in the study.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Polaris Ultra Ureteral StentThe Polaris Ultra ureteral stent is a commercially available, Health Canada-approved double-J ureteral stent used for temporary ureteral drainage after ureteroscopic stone treatment. The stent has a dual-durometer polymer design with a firmer proximal segment and a softer distal bladder segment, as well as a hydrophilic coating. In this study, a 6 French stent of a length appropriate for the participant's anatomy will be placed cystoscopically and will remain in place for approximately 4 to 6 weeks during one treatment period. | Device | Cook Double-J Followed by Polaris Ultra, Polaris Ultra Followed by Cook Double-J |
| Cook Double-J Ureteral StentThe Cook double-J ureteral stent is a commercially available, Health Canada-approved ureteral stent used as the standard-of-care comparator for temporary ureteral drainage after ureteroscopic stone treatment. It is a conventional polyurethane double-J stent with pigtail coils at the renal and bladder ends. In this study, a 6 French stent of a length appropriate for the participant's anatomy will be placed cystoscopically and will remain in place for approximately 4 to 6 weeks during one treatment period. | Device | Cook Double-J Followed by Polaris Ultra, Polaris Ultra Followed by Cook Double-J |
Primary outcome
Frequency of Bladder Spasm Episodes
Time frame: Postoperative Days 1, 3, and 7 during each of two stent treatment periods
3 secondary outcomes
Canadian Endourology Group Stent Symptom Score
Time frame: Postoperative Days 1, 3, and 7 after each stent placement, over approximately 8-12 weeks
Stent-Related Pain Intensity Measured Using a Visual Analog Scale
Time frame: Postoperative Days 1, 3, and 7 after each stent placement, over approximately 8-12 weeks
Incidence of Symptomatic Urinary Tract Infection
Time frame: During each 4- to 6-week ureteral stent indwelling period
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 3 Aug 2026.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Polaris Ultra Ureteral Stent and Cook Double-J Ureteral Stent in people with Pediatric Urolithiasis and Ureteral Stent-Related Symptoms, run by The Hospital for Sick Children at 1 site in Canada.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 7 inclusion and 8 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 3 Aug 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Canada. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Michael Chua, MD (416-813-7654 ext. 415122, michael.chua@sickkids.ca), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Frequency of Bladder Spasm Episodes (time frame: Postoperative Days 1, 3, and 7 during each of two stent treatment periods). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 3 Aug 2026.