Efficacy and Safety of Flexible Ureteroscopy With Flexible Navigable Suction Ureteral Access Sheath Versus Mini-Percutaneous Nephrolithotomy With Vacuum-Assisted Access Sheath

August 10, 2026 updated by: Mohamed Ramadan, Ain Shams University

A Comparative Study on the Efficacy and Safety of Flexible Ureteroscopy With Flexible Navigable Suction Ureteral Access Sheath Versus Mini-Percutaneous Nephrolithotomy With Vacuum-Assisted Access Sheath for the Management of Renal Stones 1- 2.5 cm in Pediatric Age Group

Mini-percutaneous nephrolithotomy (mini-PCNL) and retrograde intrarenal surgery (RIRS) are both effective treatment modalities for renal calculi measuring up to 2.5 cm in pediatric patients, demonstrating similar efficacy and complication profiles.

Suction has emerged as a potentially transformative adjunct in both percutaneous nephrolithotomy (PCNL) and RIRS. Recent studies evaluating various suction mechanisms during RIRS and mini-PCNL have demonstrated multiple benefits, including reduced operative time, higher stone-free rates (SFR), decreased intrarenal pressure (IRP) and temperature, as well as enhanced intraoperative visualization.

Both FANS-UAS in RIRS and VAAS in Mini-PCNL have shown promising outcomes in the pediatric population. Taken together, these findings suggest that suction-assisted technologies whether in RIRS or Mini-PCNL enhance both efficacy and safety in pediatric stone management.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

In children, renal stones commonly result from congenital anatomical defects, metabolic abnormalities, or recurrent urinary tract infections. Consequently, urolithiasis is more frequent in this age group and often requires more than one surgical intervention for complete management.

Mini-percutaneous nephrolithotomy (mini-PCNL) and retrograde intrarenal surgery (RIRS) are both effective treatment modalities for renal calculi measuring up to 2.5 cm in pediatric patients, demonstrating similar efficacy and complication profiles .

Currently, the majority of pediatric renal stones can be managed effectively using shock wave lithotripsy (SWL), retrograde intrarenal surgery (RIRS), or percutaneous nephrolithotomy (PCNL). Surgical interventions such as open, laparoscopic, or robotic surgery are reserved for a minority of cases involving anatomical abnormalities. As spontaneous passage of residual fragments occurs in only 20-25% of cases, achieving complete stone clearance is essential to minimize the risk of recurrence and additional interventions.

Technological advancements in endourological instrumentation have primarily aimed at minimizing procedure-related morbidity, including blood loss, postoperative pain, and renal injury. Consequently, miniaturized endoscopes and reduced-caliber access tracts (11-20 Fr) were developed, leading to the emergence of Mini-PCNL techniques specifically adapted for the management of large renal stones in pediatric patients.

The use of retrograde surgical approaches has expanded the capability to treat larger renal stones, despite often resulting in extended operative times. Due to its favorable safety profile and reduced complication rates, RIRS has gained acceptance as a preferred option for managing larger stones in pediatric patients.

For stones larger than 20 mm, RIRS monotherapy is associated with lower stone-free rate (SFR) compared to Mini-PCNL. However, RIRS offers advantages including reduced radiation exposure, fewer complications, and shorter hospital stay.

The Mini-PCNL and RIRS provide comparable efficacy and complication rates in the treatment of pediatric renal stones up to 2.5 cm. Furthermore, the study found that RIRS was associated with significantly shorter hospital stays, reduced radiation exposure, and decreased fluoroscopy time compared to Mini-PCNL.

Suction has been utilized in endourology for over 25 years, primarily in conjunction with ultrasound and ballistic lithotripsy devices, and more recently through the use of suction sheaths during PCNL. Intraoperative suction has been introduced as an effective method to remove residual fragments (RFs), thereby reducing the need for manual extraction with baskets.

Suction has also been employed in RIRS, providing multiple advantages including improved stone fragmentation and dusting, enhanced removal of debris and fragments, reduction of intra-renal temperature and pressure, as well as better intraoperative visualization.

In a prospective multicenter trial, Gauhar et al. demonstrated that the flexible and navigable suction ureteral access sheath (FANS-UAS) is safe and effective for use in pediatric RIRS, yielding high stone-free rates with low complication rates. This supports its emerging role as a valuable innovation in pediatric endourological procedures.

The initial experience using a semi-closed-circuit vacuum-assisted mini-percutaneous nephrolithotomy (Mini-PCNL) system in pediatric patients, achieving an 80% stone-free rate with no intraoperative complications and only minor postoperative events. This technique, which integrates continuous irrigation inflow with suction-controlled outflow, was found to be a safe and effective option for managing complex renal stones in children while maintaining acceptable operative times.

Study Type

Interventional

Enrollment (Estimated)

72

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

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

  • Child

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

- Renal stone burden 1- 2.5 cm confirmed by imaging (CT or ultrasound).

Exclusion Criteria:

  • Patients who refuse to participate in the study.
  • Untreated Urinary tract infection (UTI) proved by urine culture and sensitivity.
  • Uncorrected coagulopathy.
  • Anatomical anomalies or ureteral stricture precluding either surgical approach.
  • Previous surgical intervention on the same kidney.

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: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: Group A(Flexible Ureteroscopy with Flexible Navigable Suction Ureteral Access Sheath )
About 36 pediatric patients suffering from Renal Stones 1- 2.5 cm will be treated by Flexible Ureteroscopy with Flexible Navigable Suction Ureteral Access Sheath
Procedure: Flexible Ureteroscopy
To compare the efficacy and safety of flexible ureteroscopy using a flexible and navigable suction ureteral access sheath (FANS-UAS) versus mini-percutaneous nephrolithotomy (Mini-PCNL) using a vacuum-assisted access sheath (VAAS) in the management of pediatric renal stones 1-2.5 cm
Other Names:
  • Mini-Percutaneous Nephrolithotomy
Active Comparator: Group B(Mini-Percutaneous Nephrolithotomy with Vacuum-Assisted Access Sheath )
About 36 pediatric patients suffering from Renal Stones 1- 2.5 cm will be treated by Mini-Percutaneous Nephrolithotomy with Vacuum-Assisted Access Sheath
Procedure: Flexible Ureteroscopy
To compare the efficacy and safety of flexible ureteroscopy using a flexible and navigable suction ureteral access sheath (FANS-UAS) versus mini-percutaneous nephrolithotomy (Mini-PCNL) using a vacuum-assisted access sheath (VAAS) in the management of pediatric renal stones 1-2.5 cm
Other Names:
  • Mini-Percutaneous Nephrolithotomy

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Management of pediatric renal stones
Time Frame: 6 months
To compare stone-free rate (SFR) at 1 month after the procedure between RIRS using FURS-UAS and mini-PCNL using VASS in pediatric patients with renal stones 1-2.5 cm
6 months

Collaborators and Investigators

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

Sponsor

Ain Shams University

Investigators

  • Study Chair: Youssef Mahmoud kotb, Professor, Urology Department, Faculty of Medicine, Ain Shams University

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 (Actual)

June 1, 2026

Primary Completion (Estimated)

June 1, 2027

Study Completion (Estimated)

June 10, 2027

Study Registration Dates

First Submitted

August 9, 2026

First Submitted That Met QC Criteria

August 10, 2026

First Posted (Actual)

August 13, 2026

Study Record Updates

Last Update Posted (Actual)

August 13, 2026

Last Update Submitted That Met QC Criteria

August 10, 2026

Last Verified

June 1, 2026

More Information

Terms related to this study

Other Study ID Numbers

  • Management of Renal Stones

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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