Comparison of Vacuum-Assisted and Conventional Ureteral Access Sheath in Retrograde Intrarenal Surgery

July 7, 2026 updated by: Mehmet Fatih Şahin, Namik Kemal University

The Comparison of the Efficacy and Safety of Vacuum-Assisted and Conventional Ureteral Access Sheath in Retrograde Intrarenal Surgery: A Randomized Controlled Prospective Multicenter Study

This study aims to compare the efficacy and safety, the ratio of stone-free rates, and complications of two types of access sheaths used in retrograde intrarenal surgery to treat upper urothelial stones. The access sheath types are those with vacuum aspiration and the conventional ones.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

The use of ureteral access sheath (UAS) during Retrograde Intrarenal Surgery (RIRS) has been proven effective and reliable in recent years, and publications indicate that it reduces stone-free rates (SFR). Their use is also recommended in the European Urology Guidelines because it improves image quality, reduces intrarenal pressure, and shortens the operation time. For this reason, it has been routinely used in many RIRS cases. In cases where non-vacuum-assisted UAS is used, fragments during stone fragmentation remain in the kidney, and since it is not possible to remove the stones simultaneously, the image may be distorted, and the operation duration may be prolonged. All these may pave the way for postoperative infectious complications. In addition to non-vacuum-assisted UAS, new UASs with flexible ends and vacuum-assisted aspiration have been introduced in the last few years (ClearPetra). Thanks to the aspiration connected to the system, stone fragments can be removed from the body with negative pressure during stone fragmentation. Continuous circulation prevents bleeding during fragmentation and blurring of the visual field due to stone fragments. In addition, since the stone fragments pass through the edges of the sheath without breaking and are removed, a perfect field of view can be provided. Unlike the classical UAS, the tip is flexible, allowing for the safe removal of lower pole stones. Many studies in the literature compare the success and complications of RIRS in cases where conventional UAS was used and not used. In addition, there are publications related to using the newly introduced aspiration access sheath in percutaneous nephrolithotomy. In retrospective publications on using this UAS in RIRS, it has been shown that stone-free rates, operation time, hemoglobin loss, and postoperative infective complications are more successful on the 1st and 30th postoperative days compared to cases where non-vacuum-assisted UAS was used. There is no randomized controlled prospective publication on this subject. This study aims to compare the complications and stone-free rates of RIRS cases where non-vacuum-assisted UAS and new vacuum-assisted UAS were used.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
150

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • 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

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • Turkey (Türkiye)
    • Turkey
      • Tekirdağ, Turkey, Turkey (Türkiye)
        • Recruiting
        • Tekirdag Namık Kemal University

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

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Patients over 18 years of age
  • Patients below 85 years of age
  • Patients with 11-13 FR conventional/vacuum-assisted ureteral access sheath (UAS) during retrograde intrarenal surgery

Exclusion Criteria:

  • Patients with non-sterile preoperative urine culture
  • Patients with renal anatomic anomalies
  • Patients with a solitary (single) kidney
  • Patients with insufficient data
  • Patients under the age of 18, above the age of 85
  • Patients without an UAS during RIRS
  • Patients without 11-13Fr UAS during RIRS

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

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Active Comparator: Patients with conventional UAS being used in their RIRS operations
The patient population will be selected from cases determined by randomization and used with UAS without an aspiration (conventional) during RIRS.
Procedure: Retrograde intrarenal surgery
Flexible optic devices and lasers fragment kidney stones during this operation. In this surgery, an ureteral access sheath is recommended to be used.
Experimental: Patients with vacuum assisted UAS being used in their RIRS operations
The patient population will be selected from cases determined by randomization and used with UAS with an aspiration and flexible tip, different from the conventional one during RIRS.
Procedure: Retrograde intrarenal surgery
Flexible optic devices and lasers fragment kidney stones during this operation. In this surgery, an ureteral access sheath is recommended to be used.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Stone free rates
Time Frame: Stone-free status will be checked by performing a non-contrast abdominal CT scan 1 month after the operation.
Presence/absence of residual fragments in postoperative imaging, if any, diameter of longest axis in mm.
Stone-free status will be checked by performing a non-contrast abdominal CT scan 1 month after the operation.

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Complication rates
Time Frame: Peroperative complication rates will be determined during the operation, and postoperative complications will be re-evaluated during hospitalization before discharge or in the first month after discharge.
Peroperative and postoperative complication rates, whether UAS related or not
Peroperative complication rates will be determined during the operation, and postoperative complications will be re-evaluated during hospitalization before discharge or in the first month after discharge.

Collaborators and Investigators

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

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Namik Kemal University

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Study Director: Cenk M. Yazici, Professor, Namik Kemal University

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

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)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
October 1, 2024

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
October 1, 2025

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
December 1, 2026

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
November 8, 2024

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
November 9, 2024

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
November 12, 2024

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
July 8, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
July 7, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
July 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 2024.288.10.16

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

product manufactured in and exported from the U.S.

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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