Impact of Forced Diuresis on the Residual Fragment Rate After Flexible Ureteroscopy for Management of Renal Stones

August 15, 2026 updated by: Ahmed Nasser Karamany Mokhat, Ain Shams University
This randomized controlled clinical trial evaluated whether furosemide-assisted forced diuresis during flexible ureteroscopy reduced the residual fragment rate and improved stone clearance in patients with renal stones measuring up to 30 millimeters. Adult patients undergoing flexible ureteroscopy were randomized into two parallel groups: an experimental group that received intravenous furosemide during the procedure and a control group that received standard perioperative and postoperative care without furosemide. Residual stone fragments were assessed using low-dose non-contrast computed tomography on postoperative day 1 and at 6 weeks after the procedure. The primary outcome was the proportion of patients with residual stone fragments greater than 2 millimeters on postoperative day 1. Secondary outcomes included the proportion of patients with residual stone fragments greater than 2 millimeters at 6 weeks, operative time, postoperative complications, and the need for auxiliary treatment for clinically significant residual stones.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
200

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Egypt
    • Cairo Governorate
      • Cairo, Cairo Governorate, Egypt, 11511
        • Ain Shams University Hospitals (Urology Department)

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Adult patients aged 18 years or older.
  • Patients who underwent flexible ureteroscopy for renal stones measuring 30 millimeters or less.

Exclusion Criteria:

  • Patients with active urinary tract infection.
  • Patients with a history of previous open renal surgery or renal trauma.
  • Patients with contraindications to anesthesia, such as severe cardiac disease, uncontrolled diabetes mellitus, or severe coagulation disorder.
  • Patients with severe renal impairment, defined as an estimated glomerular filtration rate less than 30 milliliters per minute per 1.73 square meters.
  • Known Ureteric stricture and pelvi-ureteric junction obstruction
  • Patients with a single kidney.
  • Patients with contraindications to furosemide administration.
  • Patients with congenital renal anomalies.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Furosemide-Assisted Forced Diuresis During Flexible Ureteroscopy
During flexible ureteroscopy, participants received intravenous furosemide 40 milligrams total, divided into 20 milligrams administered 5 minutes after induction of anesthesia and 20 milligrams administered 30 minutes after the start of the procedure.
Drug: Furosemide
Intravenous furosemide was administered as a total dose of 40 milligrams during the procedure, divided into 20 milligrams given 5 minutes after induction of anesthesia and 20 milligrams given 30 minutes after the start of the procedure.
Active Comparator: Standard Care During Flexible Ureteroscopy Without Furosemide
Participants underwent flexible ureteroscopy and received standard perioperative and postoperative care without receiving intravenous furosemide or any other diuretic medication.
Other: Standard Care After Flexible Ureteroscopy Without Furosemide
Participants received standard perioperative and postoperative management after flexible ureteroscopy without administration of furosemide or any other diuretic medication.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Proportion of patients with residual stone fragments greater than 2 mm
Time Frame: Postoperative day 1 after flexible ureteroscopy
Residual stone fragments were assessed using low-dose non-contrast computed tomography (CT) performed on postoperative day 1. The outcome was reported as the proportion of patients with one or more residual renal stone fragments measuring greater than 2 mm.
Postoperative day 1 after flexible ureteroscopy

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Operative time
Time Frame: During procedure
Operative time was calculated from insertion of the ureteroscope into the urethra until completion of ureteral stent placement.
During procedure
Postoperative urinary tract infection
Time Frame: Within 7 days post-procedure
Postoperative urinary tract infection was assessed within seven days after the procedure using fever with urinary symptoms and or a positive urine culture with significant bacteriuria.
Within 7 days post-procedure
Need for auxiliary treatment for clinically significant residual stones
Time Frame: Up to 6 weeks after flexible ureteroscopy
The need for auxiliary treatment for clinically significant residual stones was recorded, including extracorporeal shock wave lithotripsy or repeat ureteroscopy.
Up to 6 weeks after flexible ureteroscopy
Proportion of patients with residual stone fragments greater than 2 mm at 6 weeks
Time Frame: 6 weeks after flexible ureteroscopy
Residual stone fragments were assessed using low-dose non-contrast computed tomography (CT) performed 6 weeks after flexible ureteroscopy. The outcome was reported as the proportion of patients with one or more residual renal stone fragments measuring greater than 2 mm.
6 weeks after flexible ureteroscopy

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Ain Shams University

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
January 1, 2026

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
July 1, 2026

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
July 1, 2026

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
December 16, 2025

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
December 30, 2025

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
January 13, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
August 18, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
August 15, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
August 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • FMASU MS 686/2025

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

De-identified individual participant data that underlay the reported results were planned to be shared with other researchers. The shared data were planned to include baseline characteristics, stone characteristics, intraoperative details, stone-free outcome on non-contrast computed tomography at four weeks, and postoperative outcomes including complications, pain scores, urine output in the first 24 hours, and need for auxiliary treatment. A data dictionary was planned to be provided.

IPD Sharing Time Frame

The data were planned to become available after completion of the study and acceptance of the thesis or publication of the primary results, and were planned to remain available for five years.

IPD Sharing Access Criteria

Access was planned to be provided to qualified researchers upon reasonable request, after review of a brief proposal and analysis plan, and after execution of a data use agreement. Data were planned to be shared in a secure electronic format with de-identification applied.

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL
  • SAP
  • ICF
  • ANALYTIC_CODE
  • CSR

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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