Forced diuresis with furosemide to reduce leftover stone fragments after flexible ureteroscopy

FIRESTONES : Impact of Forced Diuresis on the Residual Fragment Rate After Flexible Ureteroscopy for Destruction of Kidney Stones With Laser: a Randomized Controlled Two-parallel Group Multicenter Trial With Blinding Evaluation

Phase 3 Interventional University Hospital, Tours · NCT05916963

This trial will try a single dose of furosemide plus IV fluids during flexible ureteroscopy to see if it lowers the amount of leftover kidney stone fragments in adults having laser stone treatment.

Quick facts

PhasePhase 3
Study typeInterventional
Enrollment374 (estimated)
Ages18 Years to 80 Years
SexAll
SponsorUniversity Hospital, Tours Academic / other
Locations9 sites (Angers and 8 other locations)
Trial IDNCT05916963 on ClinicalTrials.gov

What this trial studies

Flexible ureteroscopy with laser is a common method to break kidney stones into small fragments, but some micro‑fragments often remain in the kidney after the procedure. This Phase 3 interventional trial gives a 40 mg injection of furosemide together with intravenous hydration during the procedure to produce forced diuresis and increase urine flow through the renal cavities. The aim is to reduce the rate of residual fragments left in the kidney at the end of surgery compared with usual care. Eligible patients are adults aged 18–79 undergoing flexible ureteroscopy who do not have contraindications to furosemide such as severe electrolyte disturbances, hypovolemia, or renal failure with oligo‑anuria.

Who should consider this trial

Good fit: Adults aged 18 to 79 who are scheduled for flexible ureteroscopy with laser for kidney stones, can give informed consent, and have no contraindication to furosemide are ideal candidates.

Not a fit: Patients with contraindications to loop diuretics (severe renal failure, marked hypokalemia, severe hyponatremia, hypovolemia), protected populations (pregnant or legally protected persons), or those not undergoing ureteroscopy are unlikely to benefit.

Why it matters

Potential benefit: If successful, the approach could lower the number of leftover fragments after ureteroscopy, reducing recurrence and the need for further procedures.

How similar studies have performed: Forced diuresis has shown positive results in several studies after extracorporeal shock wave lithotripsy, but using furosemide with IV hydration specifically during flexible ureteroscopy has not been specifically analyzed before.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Patients ≥ 18 years old and \< 80 years old
* With the need to perform a flexible ureteroscopy with destruction of the kidney stones with laser
* Participants covered by or entitled to social security
* Written informed consent obtained from the participant
* Ability for participant to comply with the requirements of the study

Exclusion Criteria:

* Persons covered by articles L1121-5 to L1121-8 of the CSP (corresponding to all protected persons: pregnant women, parturients, nursing mothers, persons deprived of their liberty by judicial or administrative decision, minors, and persons subject to a legal protection measure: guardianship or trusteeship)
* Contra-indication to Furosemide:

  * Hyper-sensitivity to the active substance or one of the excipients
  * Hyper-sensitivity to Sulfonamide
  * Renal failure with oligo-anuria refractory to Furosemide
  * Hypokalemia \< 3,5 mmol/L
  * Severe hyponatremia
  * Hypovolemia with or without hypotension or dehydration
  * Ongoing hepatitis, hepatic insufficiency severe and hepatic encephalopathy
* Patient having Furosemide as usual treatment
* Patient requiring an injection of Aminoside or Vancomycin before or during the procedure
* Participation in other interventional research with an investigational drug or medical device

Where this trial is running

Angers and 8 other locations

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Kidney Stone
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.