FANS vs Standard Ureteral Access Sheath in fURS (CLEAR-URS)

March 10, 2026 updated by: Luca Villa, IRCCS San Raffaele

Comparative Study on the Efficacy of the Ureteral Access Sheath With Integrated Suction FANS Versus the Standard Sheath in Patients With Renal Calculi Undergoing Ureterorenoscopy and Laser Lithotripsy: a Prospective, Randomized, Interventional, Single-center Study

This is a prospective, interventional single blinded, randomized, single-center study designed to compare the efficacy of a ureteral access sheath with integrated suction (FANS) versus a standard ureteral access sheath (UAS) in patients undergoing ureterorenoscopy and laser lithotripsy for renal stones. The hypothesis is that the use of the FANS device improves stone-free rates and reduces postoperative infectious complications compared to the standard sheath.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Detailed Description

Single-center, prospective, randomized, interventional, single blinded study. Participants with renal calculi undergoing ureterorenoscopy and laser lithotripsy will be randomized in a 1:1 ratio to receive either a standard ureteral access sheath (UAS) or the FANS (Flexible and Navigable Suction) sheath. Randomization will be stratified by stone characteristics, specifically stone density (≤1000 vs >1000 HU) and stone volume (<500 vs ≥500 mm³), as recorded on preoperative imaging, to reduce potential imbalance between study arms.

Study Type

Interventional

Enrollment (Estimated)

134

Phase

  • 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 Contact

Study Contact Backup

Study Locations

  • Italy
      • Milan, Italy
        • IRCCS Ospedale San Raffaele

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

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  1. Participant is willing and able to provide written informed consent before any study-specific procedures are performed.
  2. Male or female, aged 18 years or older.
  3. Diagnosed with renal calculi ≥5 mm in diameter, confirmed by imaging, and eligible for fURS with laser lithotripsy according to European Association of Urology (EAU) guidelines.
  4. In stable general health and fit for elective endoscopic surgery under general anesthesia.

  5. Willing and able to comply with all study-related procedures, including follow-up imaging and clinical assessments.

    -

Exclusion Criteria:

  1. Solitary kidney (monorenal patients).
  2. Untreated positive urine culture or ongoing urinary tract infection not resolved with appropriate antibiotic therapy prior to surgery.
  3. Known anatomical abnormalities of the urinary tract that may interfere with ureteroscopic access or device placement (e.g., ureteral stricture, congenital malformations).
  4. Pregnancy or breastfeeding at the time of enrollment or planning pregnancy during the study period. In all female patients, a Gravindex test is performed on the day of admission; contraceptive measures are not required
  5. Concomitant ureteral stone
  6. Ureteral stenosis
  7. Known allergy or hypersensitivity to materials used in the investigational or control ureteral access sheath.
  8. Any severe comorbid condition (e.g., uncontrolled cardiovascular disease, severe coagulopathy, active malignancy) that in the opinion of the investigator would interfere with study participation or increase procedural risk.
  9. Any psychological, cognitive, or social condition that may limit the ability to provide informed consent or comply with follow-up procedures.

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: Other
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Single

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Standard Ureteral Access Sheath (UAS)
Participants receive the standard ureteral access sheath during ureterorenoscopy and laser lithotripsy.
Device: Standard ureteral access sheath
Participants undergo flexible ureterorenoscopy and laser lithotripsy using a standard ureteral access sheath according to institutional practice.
Experimental: FANS Ureteral Access Sheath (Elephant-II)
Participants receive the Flexible and Navigable Suction (FANS) ureteral access sheath during ureterorenoscopy and laser lithotripsy.
Device: Flexible and Navigable Suction (FANS) Ureteral Access Sheath
The Flexible and Navigable Suction (FANS) ureteral access sheath (Elephant-II), which enables active suction during flexible ureterorenoscopy and laser lithotripsy.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Radiological stone-free rate (absence of residual fragments >=4 mm) assessed by low-dose non-contrast CT scan
Time Frame: Within 3 months (+/- 1 month) post-procedure
Proportion of participants classified as stone-free based on radiological evaluation using low-dose non-contrast computed tomography. Stone-free status is defined as absence of residual stone fragments >=4 mm.
Within 3 months (+/- 1 month) post-procedure

Collaborators and Investigators

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

Sponsor

IRCCS San Raffaele

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 (Estimated)

March 15, 2026

Primary Completion (Estimated)

January 1, 2029

Study Completion (Estimated)

January 1, 2029

Study Registration Dates

First Submitted

February 17, 2026

First Submitted That Met QC Criteria

March 6, 2026

First Posted (Actual)

March 11, 2026

Study Record Updates

Last Update Posted (Actual)

March 12, 2026

Last Update Submitted That Met QC Criteria

March 10, 2026

Last Verified

March 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • CLEAR-URS

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

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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