Stent removal helps to spontaneously pass ureteral stones

ISRCTN ISRCTN12112914
DOI https://doi.org/10.1186/ISRCTN12112914
Secondary identifying numbers KEK-Be 2017-01698
Submission date
28/07/2019
Registration date
05/08/2019
Last edited
04/12/2024
Recruitment status
Stopped
Overall study status
Stopped
Condition category
Urological and Genital Diseases
Prospectively registered
Protocol
Statistical analysis plan
Results
Individual participant data
Record updated in last year

Plain English Summary

Background and study aims
In some clinical situations patients with symptomatic ureteral stone disease patients are treated with double J stents before definitive stone treatment can be performed. Still, spontaneous stone passage is not uncommon after double J stent insertion. The question arises therefore whether secondary intervention is necessary at all as potential complications might thus be avoided. The aim of this trial is to assess whether removal of the double J stent can spare additional surgery and whether time point of removal (1 vs. 4 weeks) matters. Additionally, we try to distinguish which patients are optimal candidates for double J stent removal prior to secondary surgery and who should undergo surgery without prior stent removal

Who can participate?
Patients older than 18 years of age and who have received a double J stent due to a single ureteral stone. The ureteral stone needs to be radiopaque to facilitate detection of localization by X-ray

What does the study involve?
Before scheduled secondary intervention for stone extraction the patients will by assessed for spontaneous stone passage by patient interview and in case of no spontaneous stone passage radiological assessment (X-ray or low-dose computed tomography). In case of spontaneous stone passage the double J stent will be extracted by flexible cystoscopy and patients are discharged without the scheduled surgery. In case of stone persistence, the double J stent will be removed by flexible cystoscopy. If the stone passes within 24 hours the patients will be discharged without the scheduled secondary surgery. In case of stone persistence after double J stent removal the scheduled secondary surgery (ureteroscopy or SWL) will be performed for stone removal

What are the possible benefits and risks of participating?
Benefits:
Possible avoidance of secondary surgery for stone extraction.
Risks:
Possible unnecessary flexible cystoscopy in local anesthesia before secondary treatment in case of failure of spontaneous stone passage after double J stent removal. However, this represents a minor intervention and the benefit of not having to undergo surgery outweighs the risk.
Possible renal colic after double J stent removal without prior stone passage. However, patient will be guarded in hospital and have immediate access to analgetics.
Possible urinary tract infection. However, patient will be administered an antibiotic prophylaxis to minimize this potential risk

Where is the study run from?
1. University Hospital Bern, Switzerland
2. CHUV Lausanne University Hospital, Switzerland

When is the study starting and how long is it expected to run for?
November 2019 to November 2023

Who is funding the study?
Investigator initiated and funded

Who is the main contact?
Prof. Beat Roth
beat.roth@insel.ch

Contact information

Prof Beat Roth
Scientific

Department of Urology
CHUV
University Hospital
University of Lausanne
Switzerland
Lausanne
1011
Switzerland

ORCiD logoORCID ID 0000-0002-7369-650X
Phone +41316322045
Email beat.roth@insel.ch

Study information

Study designProspective randomized trial
Primary study designInterventional
Secondary study designRandomised controlled trial
Study setting(s)Hospital
Study typeTreatment
Participant information sheet Not available in web format, please use the contact details below to request a patient information sheet
Scientific titleA treatment strategy to help select patients who may not need secondary intervention to remove symptomatic ureteral stones after previous stenting
Study acronymNOSTENT
Study hypothesisTo evaluate whether removal of the ureteral stent the day before scheduled secondary intervention facilitates spontaneous ureteral stone passage and thus can spare the pre-stented patient this surgery
Ethics approval(s)Approved 21/11/2017, Ethical Committee of the Canton of Bern (Kantonale Ethikkommission für die Forschung, Murtenstrasse 31, 3010 Bern, Switzerland; +41 31 633 70 70; info.kek.kapa@gef.be.ch), ref: KEK-Be 2017-01698
ConditionUreteral stone patients after previous stenting
InterventionMethodology:
Patients presenting with a solitary, radiopaque, ureteral stone after double J stenting are eligible for participation. They will be randomized 1:1 for stent removal 1 vs. 4 weeks after stent placement.
Baseline diagnostics will be performed using non-contrast-enhanced computed tomography (NECT) in all patients. Stone size will be measured in three dimensions on axial and coronal images. Stone density will be measured using the bone window on the magnified axial NECT of the stone at maximal diameter. Before and/or during double J stent placement, conventional X-ray scan will be used to evaluate whether the stone is radiopaque. If the stone is radiolucent the patient will be excluded from further analysis. Patients are told to strictly filter their urine. Before discharge from hospital, patients will be randomized and secondary intervention is scheduled.
If no spontaneous stone passage is noted while the double J stent is in place, radiological assessment (X-ray or low-dose NECT) is performed the day prior to scheduled secondary intervention. Immediately thereafter, the double J stent is removed from all patients under local anesthesia using flexible cystoscopes in the outpatient clinic. A single shot of antibiotic prophylaxis (amoxicillin/clavulanate, ciprofloxacin or co-trimoxazole) is given at the time of stent removal. If spontaneous stone passage occurs, patients are discharged and followed up after 2 to 4 weeks by renal ultrasound for residual hydronephrosis. In the case of stone persistence, patients are hospitalized overnight and told to filter their urine. No additional medication (e.g. α-blockers, NSAID) will be given on a routine basis. Pain-induced additional use of analgesics (NSAID and metamizole as first choice; pethidine as second choice) and any other adverse events (e.g. urinary tract infection (UTI), renal colic) will be recorded. Spontaneous stone passage or persistence of the stone will be documented either by presenting the filtered stone and/or radiologically (X-ray or low-dose NECT) the following day. Secondary intervention will only be performed in case of persistence of the stone.
Total duration of treatment:
24h
Follow up:
Patients with spontaneous stone passage are followed up 2 to 4 weeks after double J stent removal for residual hydronephrosis.
Patients without spontaneous stone passage are followed up one day after double J stent removal and evaluated by radiological means (X-ray or low-dose NECT) and ultrasound for stone persistence. Secondary intervention (ureteroscopy or SWL) will then be followed the same day.
Randomization:
1:1 grouping by computer program
Intervention typeDevice
Pharmaceutical study type(s)
PhaseNot Applicable
Drug / device / biological / vaccine name(s)Not provided at time of registration
Primary outcome measureUreteral stone-free rate at the time of and 24 hours after double J stent removal. As assessed by patient interview and/or radiological assessment.
Secondary outcome measuresMeasured continuously throughout trial:
1. Predictors of spontaneous stone passage:
1.1 Stone size (diameter)
1.2 Stone location [proximal, mid- or distal ureter]
1.3 Stone density
1.4 Stent dwell time
1.5 Stone movement while stent indwelling. To assess stone movement, the dislocation of the stone from the initial spot immediately after double J placement was measured and compared to the X-ray pictures before stent removal. Because natural breathing movements of the patient can make evaluation of the exact stone location rather difficult, only stone movement of ≥5cm is measured and counted as stone movement.
1.6 Patient’s age
1.7 Patient’s gender
2. Adverse events:
2.1 Pain-induced additional use of analgesics
2.2 Urinary tract infection (UTI)
Overall study start date01/11/2019
Overall study end date01/11/2023
Reason abandoned (if study stopped)Lack of funding/sponsorship

Eligibility

Participant type(s)Patient
Age groupAdult
Lower age limit18 Years
SexBoth
Target number of participants202
Participant inclusion criteria1. Ureteral stone
2. Previous stenting
3. Stone still in place
4. Aged over 18 years
Participant exclusion criteriaDoes not meet inclusion criteria
Recruitment start date01/11/2019
Recruitment end date01/11/2023

Locations

Countries of recruitment

  • Switzerland

Study participating centres

University Hospital Bern
Freiburgstrasse
Bern
3010
Switzerland
CHUV Lausanne University Hospital
Rue de Bugnon 46
1011 Lausanne
Lausanne
1011
Switzerland

Sponsor information

Inselspital, Universitätsspital Bern
Hospital/treatment centre

Inselspital Department of Urology
Freiburgstrasse
3010 Bern
Bern
3010
Switzerland

Phone 0316322180
Email Urology.Berne@insel.ch
Website https://www.insel.ch
ROR logo "ROR" https://ror.org/01q9sj412

Funders

Funder type

Other

Investigator initiated and funded

No information available

Results and Publications

Intention to publish date31/12/2023
Individual participant data (IPD) Intention to shareNo
IPD sharing plan summaryData sharing statement to be made available at a later date
Publication and dissemination planStone passage will be published in one of the 3 top journals of Urology; by the end of 2023
IPD sharing planThe current data sharing plans for this study are unknown and will be available at a later date

Editorial Notes

04/12/2024: The study was stopped before recruitment due to financial issues.
22/01/2020: Internal review.
01/08/2019: Trial’s existence confirmed by Ethical Committee of the Canton of Bern