Reduction of Stent Associated Morbidity by Minimizing Stent Material.

Study Overview
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Brief Summary
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After providing informed consent, patients will be randomized into one of two groups (single-blinded): Group 1 will receive a standard Percuflex® (Boston scientific) ureteral stent. Diameter: 6F, length according to surgeons' estimation. Patients in Group 2 will receive a Suture-Stent adjusted to the individual stone location. All participant receive standardized patient information, using a validated leaflet on ureteral stenting and associated morbidity. In both groups, patients will complete the Ureteral Stent Symptoms Questionnaire (USSQ) 1 week after stent insertion, prior to stent removal (i.e. 2-6 weeks after insertion) and after (2-6 weeks) stent removal. USSQ results after stent removal serve as an assessment of baseline symptoms. During secondary stone removal, stents are removed and ureteral dilatation / access is assessed. The removed stents will be assessed for biofilm formation within the framework of an approved and ongoing study on the development of a Biofilm-model (EKSG 15/084). Potential complications and adverse events are assessed at all scheduled and unscheduled patient visits.

Official Title
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Reduction of Stent Associated Morbidity by Minimizing Stent Material: A Prospective Randomized Single-blind Study Assessing a Novel Suture-Stent.

Conditions
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Ureteral Stent Related Morbidity

Intervention / Treatment
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* Device: ureteral stenting with standard or modified ureteral stent


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Kidney stone(s) and/or ureteral stone(s) at the iliacal vessel crossing of the ureter or proximally Indication for ureteral stenting for the preparation of a secondary intervention Informed consent Exclusion Criteria: Patients younger than 18 years Bilateral ureteral stenting Stenting because of malignant obstruction Mentally retarded patients Obstructive pyelonephritis at the time of stent insertion Additional operations performed during the stent indwelling time

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: ureteral stenting with standard ureteral stent<br>Group 1 will receive a standard ureteral stent. Diameter: 6F, length according to surgeons' estimation and patient's height. | Device: ureteral stenting with standard or modified ureteral stent<br>* Ureteral stenting because of kidney and or ureteral stones at the iliacal vessel crossing of the ureter or proximally<br>|
| Active Comparator: ureteral stenting with suture-stent<br>In Group 2, a modification of the standard ureteral stent will be inserted. The stent will be cut through obliquely according to the position of the ureteral calculus. The extend to be removed can be easily measured by the retrograde probing catheter and is replaced by a monofilament, non-absorbable suture as described previously by Vogt et al. (W J Urol, 2015). This suture can be easily attached by puncturing the bevelled stent end. | Device: ureteral stenting with standard or modified ureteral stent<br>* Ureteral stenting because of kidney and or ureteral stones at the iliacal vessel crossing of the ureter or proximally<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Difference in Pain-Symptoms and Urinary-Symptoms as assessed by the validated questionnaire USSQ (ureteral stent symptoms questionnaire) between standard stent and Suture-Stent | Difference in the USSQ subscores (Pain-Symptoms and Urinary-Symptoms) between standard stent and Suture-Stent (symptoms assessed one week after insertion and corrected for baseline symptoms by assessing symptom subscores 2-6 weeks after stent removal) | One week after stent insertion and 2-6 weeks after removal | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Difference in Pain-Symptoms and Urinary-Symptoms as assessed by the validated questionnaire USSQ (ureteral stent symptoms questionnaire) between standard stent and Suture-Stent | Difference in the USSQ subscores (Pain-Symptoms and Urinary-Symptoms) between standard stent and Suture-Stent (symptoms assessed before removal (i.e. 2-6 weeks after insertion) and corrected for baseline symptoms by assessing symptom subscores 2-6 weeks after stent removal). | 2-6 weeks after stent insertion and 2-6 weeks after removal | 
| Difference in total morbidity as assessed by the validated questionnaire USSQ (ureteral stent symptoms questionnaire) | Difference in the USSQ total score between standard ureteral stent and Suture- Stent (symptoms assessed before removal (i.e. 2-6 weeks after insertion) and corrected for baseline symptoms by assessing symptom subscores 2-6 weeks after stent removal). | 2-6 weeks after stent insertion and 2-6 weeks after removal | 
| Difference in type of morbidity as assessed by USSQ sub-scores and single-items (e.g. equal function, work incapacity, hematuria and others) between standard ureteral stent and Suture-Stent | Difference in the USSQ sub scores and items (i.e. general health, work performance, sexual matters, items, additional problems, GQ, assessment of haematuria: items U8 and U9) between standard ureteral stent and Suture-Stent (symptoms assessed before removal (i.e. 2-6 weeks after insertion) and corrected for baseline symptoms by assessing symptom subscores 2-6 weeks after stent removal). | 2-6 weeks after stent insertion and 2-6 weeks after removal | 
| Comparison of the ureteral expanse after stenting with the new Suture-Stent and the standard ureteral stent at the time of secondary intervention | Comparison of the ureteral expanse after stenting with the new Suture-Stent and the standard ureteral stent at the time of secondary intervention (measured by a retrograde ureterography) at three locations of the ureter (i.e. proximal, middle and distal ureter). | 2-6 weeks after stent insertion | 
| Differences of ureteral access with a 9.5 F ureterorenoscopy device after stenting with the new Suture-Stent or the standard ureteral stent at the time of secondary intervention (URS) | Differences of ureteral access with a 9.5 F ureterorenoscopy device after stenting with the new Suture-Stent or the standard ureteral stent at the time of secondary intervention (URS) measured by the success of: Entering the whole ureter or Insertion of an access sheath 14/12F; Complete stone removal. | 2-6 weeks after stent insertion | 
| Comparison of the mucosal irritation after stenting with the new Suture-Stent and the standard ureteral stent at the time of secondary intervention | Comparison of the mucosal irritation after stenting with the new Suture-Stent and the standard ureteral stent at the time of secondary intervention (measured by a grading: no, light, heavy irritation) at two locations (periostial and ureteral). | 2-6 weeks after stent insertion | 
| Comparison of practicability of Suture-Stent and standard ureteral stent | Comparison of practicability of Suture-Stent and standard ureteral stent (i.e. insertion time, problems with insertion or removal) | 2-6 weeks after stent insertion | 
| Comparison of the total biofilmmass and number of bacteria on stent surface between the Suture-Stent and standard ureteral stent | Comparison of the total biofilmmass and number of bacteria on stent surface between the Suture-Stent and standard ureteral stent measured at time of stent removal (2-6 weeks after insertion) | At the time of stent insertion and 2-6 weeks after insertion | 
| Microbiological investigation of the suture-part of the Suture-stent | Microbiological investigation of the suture-part of the Suture-stent: total biofilmmass, number of bacteria | 2-6 weeks after stent insertion | 
| Assessment of complications not assessed by USSQ during intervention and indwelling time (i.e. intraoperative complications, additional hospitalizations, prolongation of hospitalization, ureteral injuries) | Assessment of complications not assessed by USSQ during intervention and indwelling time (e.g. perioperative adverse events according to Clavien-Dindo classification, stent dislocation or dysfunction during indwelling time). | At the time of stent insertion until 2-6 weeks after stent removal | 
| Assessment of medication that had to be taken in both groups | Assessment of medication that had to be taken in both groups | At the time of stent insertion until 2-6 weeks after stent removal | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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ureteral stent