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

NCT07336485 | Completed

• 1 other identifier: FMASU MS 686/2025
• Study Type: interventional
• Target: 200
• Locations: 1 country
• Sites: 1

Brief Summary

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.

Conditions

Kidney Stones

Keywords

Kidney stones; renal calculi; nephrolithiasis; flexible ureteroscopy; ureteroscopy; laser lithotripsy; residual stone fragments; stone-free rate; forced diuresis; furosemide; non-contrast computed tomography

Outcome Measures

Primary Outcomes (1)

• Proportion of patients with residual stone fragments greater than 2 mm

  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 Outcomes (4)

• Operative time

  During procedure

• Postoperative urinary tract infection

  Within 7 days post-procedure

• Need for auxiliary treatment for clinically significant residual stones

  Up to 6 weeks after flexible ureteroscopy

• Proportion of patients with residual stone fragments greater than 2 mm at 6 weeks

  6 weeks after flexible ureteroscopy

Study Arms (2)

Furosemide-Assisted Forced Diuresis During Flexible Ureteroscopy

EXPERIMENTAL

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

Standard Care During Flexible Ureteroscopy Without Furosemide

ACTIVE COMPARATOR

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

Interventions

Furosemide DRUG

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.

Furosemide-Assisted Forced Diuresis During Flexible Ureteroscopy

Standard Care After Flexible Ureteroscopy Without Furosemide OTHER

Participants received standard perioperative and postoperative management after flexible ureteroscopy without administration of furosemide or any other diuretic medication.

Standard Care During Flexible Ureteroscopy Without Furosemide

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

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

You may not qualify if:

• 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.

Sponsors & Collaborators

• Ain Shams University: lead

Study Sites (1)

Ain Shams University Hospitals (Urology Department)

Cairo, Cairo Governorate, 11511, Egypt

Location

MeSH Terms

Conditions

Kidney Calculi; Nephrolithiasis

Interventions

Furosemide

Condition Hierarchy (Ancestors)

Kidney Diseases; Urologic Diseases; Female Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Urogenital Diseases; Urolithiasis; Urinary Calculi; Male Urogenital Diseases; Calculi; Pathological Conditions, Anatomical; Pathological Conditions, Signs and Symptoms

Intervention Hierarchy (Ancestors)

Sulfanilamides; Sulfonamides; Amides; Organic Chemicals; Aniline Compounds; Amines; Sulfones; Sulfur Compounds

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Resident of Urology

Model Details: Participants were randomly assigned in a one-to-one ratio to receive either intravenous furosemide-assisted forced diuresis during flexible ureteroscopy or standard care without furosemide during flexible ureteroscopy.

Study Record Dates

• First Submitted: December 16, 2025
• First Posted: January 13, 2026
• Study Start: January 1, 2026
• Primary Completion: July 1, 2026
• Study Completion: July 1, 2026
• Last Updated: August 18, 2026

Record last verified: 2026-08

Data Sharing

• IPD Sharing: Will not share

Locations

EG (1)