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

This randomized controlled clinical trial evaluated whether furosemide-assisted forced diuresis during flexible ureteroscopy reduced the residual fragment rate and improved the stone-free rate after flexible ureteroscopy for management of medium sized renal stones measuring up to 30 millimeters. Adult patients undergoing flexible ureteroscopy for renal stones 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. Stone-free status and residual fragments were assessed using non-contrast computed tomography performed four weeks after the procedure, and residual fragments were classified by fragment size. Secondary outcomes included operative time, length of hospital stay, postoperative complications, total urine output in the first 24 hours, and the need for additional treatments for significant residual stones.

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. * Patients with a single kidney. * Patients with contraindications to furosemide administration. * Patients with congenital renal anomalies.