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

Pedro de Figueiredo Buchalla

Status and phase: Enrolling; Phase 4

Conditions: Ureteral Access Sheath; Alpha Blocker; Nephrolithiasis

Treatments: Drug: No intervention (observational study); Drug: Experimental: Alpha-blocker group

Study type: Interventional

Funder types: Other

Identifiers

NCT07124299

FMABC-ALFAURS-2025-01

Details and patient eligibility

About

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.

Enrollment: 140 estimated patients

Sex: All

Ages: 18+ years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Age ≥ 18 years
• Diagnosis of nephrolithiasis with surgical indication for flexible ureterorenolithotripsy
• Ability to provide written informed consent

Exclusion criteria

• Age < 18 years
• Pregnancy
• History of ureteral stricture, prior ureteral reconstructive surgery, and/or abdominal or pelvic radiotherapy
• Prior ureteroscopy or ipsilateral double-J stent placement within the past 3 months
• Chronic use of alpha-blockers for benign prostatic hyperplasia or medical expulsive therapy for ureteral stones

Trial design

Primary purpose: Treatment

Allocation: N/A

Interventional model: Parallel Assignment

Masking: Single Blind

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140 participants in 2 patient groups, including a placebo group

Experimental: Alpha-blocker group

Active Comparator group

Description:

Participants will receive an alpha-blocker (e.g., tamsulosin 0.4 mg orally once daily) for 7 consecutive days prior to flexible ureterorenolithotripsy. The medication aims to relax the ureteral smooth muscle and facilitate the insertion of the ureteral access sheath during surgery. All surgical procedures will follow the standard protocol used in the participating hospitals.

Treatment:

Drug: Experimental: Alpha-blocker group

No Intervention: Control group

Placebo Comparator group

Description:

Participants will undergo flexible ureterorenolithotripsy without the use of alpha-blockers prior to surgery. All other aspects of perioperative care and surgical technique will be identical to those of the experimental group.

Treatment:

Drug: No intervention (observational study)