Clinical Research Directory

Ureteral Access Strategies in Retrograde Intrarenal Surgery

Retrograde intrarenal surgery (RIRS) is a standard minimally invasive treatment for kidney stones up to 20 mm. During the procedure, irrigation fluid raises the pressure inside the kidney and laser energy raises the fluid temperature. High intrarenal pressure has been linked to postoperative pain, fever and infection. Ureteral access sheaths are used to improve fluid outflow, and newer flexible and navigable suction access sheaths (FANS) add active aspiration to keep pressure low and remove stone fragments. This randomized controlled trial compares three ureteral access strategies in adults undergoing RIRS: a flexible and navigable suction access sheath, a conventional ureteral access sheath, and no access sheath. The main question is whether the access strategy affects pain 6 hours after surgery. The study also compares intrarenal pressure and temperature during surgery, the amount of irrigation fluid used and retained, stone-free status on computed tomography (CT), and complications.

Medication Facilitated Ureteral Access Sheath Deployment During Ureteroscopy: The Impact of One Week of Preoperative Tamsulosin

The goal of this clinical trial is to assess whether tamsulosin given one week prior to renal or ureteric stone surgery would improve the success rate of ureteral access sheath deployment and decrease ureteral injury

Long-term Safety of UAS-assisted vs Sheathless RIRS in Non-prestented Patients

This retrospective comparative cohort study will include adult patients who underwent primary RIRS for renal stones ≤20 mm at Al-Azhar University Hospitals between January 2020 and December 2025. Patients will be classified by whether a ureteral access sheath (UAS) was used during the index RIRS, and all eligible patients will be invited for active long-term follow-up (minimum 12 months) to assess the composite outcome of delayed ipsilateral ureteral stricture or new/progressive ipsilateral hydronephrosis and other safety and efficacy outcomes. Propensity-score methods and adjusted regression analyses will be used to control confounding.

MIRABEGRON AND UAS OUTCOMES DURING RIRS

The aim of this study is to evaluate whether there is a difference in the passage rate of the ureteral access sheath between patients who used mirabegron (a beta-3 receptor agonist) for overactive bladder and those who underwent retrograde intrarenal surgery for kidney stones, and those who did not use mirabegron. Considering that beta-3 receptors in the smooth muscle of the ureter cause relaxation in the ureter, the hypothesis that the passage rate of the access sheath increases in those using mirabegron, thus facilitating access to kidney stones and improving surgical success, will be investigated.

Alpha-Blockers Prior to Ureteral Access Sheath Placement in Flexible Ureteroscopy: A Randomized Prospective Study

This study aims to evaluate whether the use of alpha-blockers before flexible ureterorenolithotripsy facilitates the passage of the ureteral access sheath. The trial will enroll adult patients diagnosed with kidney stones who are scheduled for flexible ureteroscopy. Participants will be randomly assigned to receive or not receive alpha-blockers for seven days before surgery. The primary outcome is the rate of successful sheath placement without the need for a second procedure. Secondary outcomes include the incidence of ureteral injuries and the need for additional surgical interventions. The goal is to improve surgical efficiency and patient outcomes in the treatment of kidney stones.