Stone Cone Device vs. Standard URS for Proximal Ureteral Calculi

August 14, 2026 updated by: Akbar Shah, Provincial Headquarter Teaching Hospital Gilgit

A Randomized Controlled Trial Comparing Stone Clearance and Retrograde Migration in Ureteroscopic Pneumatic Lithotripsy for Proximal Ureteral Calculi Performed With and Without the Stone Cone Anti-Retropulsion Device

Retrograde migration of stone fragments into the kidney during ureteroscopic lithotripsy (URS) for proximal ureteral stones is a common technical challenge, occurring in 5-40% of cases. This can lead to residual fragments and lower stone-free rates. The Stone Cone is an anti-retropulsion device designed to trap fragments and prevent their migration. This study will test the hypothesis that the use of the Stone Cone during URS pneumatic lithotripsy will result in a significantly higher stone clearance rate at 48 hours post-procedure compared to the standard technique without the device.

Study Overview

Status

Status

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

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.

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 (Actual)

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.
100

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 Locations

  • Pakistan
    • Gilgit-Baltistan
      • Gilgit, Gilgit-Baltistan, Pakistan, 54000
        • Provincial Headquarter Teaching Hospital, Gilgit.

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

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • A solitary proximal ureteral stone ≤ 2 cm in size as confirmed by imaging.
  • Normal renal function.

Exclusion Criteria:

  • Active urinary tract infection (clinical features or pyuria).
  • Bleeding disorder (abnormal prothrombin time or activated partial thromboplastin time).
  • Chronic kidney disease (raised urea and creatinine).
  • Stone > 2 cm in size.

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.
Experimental: Group A: Stone Cone Device
Participants will undergo ureteroscopic pneumatic lithotripsy for a proximal ureteral calculus. The Stone Cone device will be positioned fluoroscopically proximal to the stone before fragmentation and used to prevent retrograde stone migration and trap fragments for extraction.
Procedure: Ureteroscopic Pneumatic Lithotripsy with Cone Device
Patients will undergo ureteroscopic pneumatic lithotripsy under general anesthesia. The Stone Cone device (Boston Scientific, Natick, MA) will be advanced through the ureteroscope and positioned fluoroscopically proximal to the calculus before fragmentation. The device will create a mechanical barrier to prevent retrograde stone migration into the renal pelvis and will be used to trap and extract fragments upon withdrawal. A ureteral double-J stent will be placed at the end of the procedure.
Active Comparator: Group B: Standard URS
Participants will undergo standard ureteroscopic pneumatic lithotripsy for a proximal ureteral calculus without the use of any anti-retropulsion device.
Procedure: Standard Ureteroscopic Pneumatic Lithotripsy
Patients will undergo standard ureteroscopic pneumatic lithotripsy under general anesthesia without the use of any anti-retropulsion device. Stone fragmentation and fragment extraction will be performed using standard tools (pneumatic lithotripter, grasping forceps, or basket) as per the surgeon's discretion. A ureteral double-J stent will be placed at the end of the procedure.

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 Clearance Rate
Time Frame: 48 hours
The proportion of participants achieving a stone-free status, defined as the absence of stones on plain X-ray of the kidneys, ureters, and bladder (KUB) and abdominal ultrasonography performed 48 hours after the ureteroscopic lithotripsy procedure.
48 hours

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
Incidence of Intraoperative Complications
Time Frame: 2 hours
The number of participants experiencing complications such as ureteral perforation or significant bleeding during the procedure.
2 hours
Operative Time
Time Frame: 120 minutes
The total duration of the ureteroscopic procedure, measured in minutes.
120 minutes
Hospital Stay Duration
Time Frame: 5 days
The length of the patient's hospital stay following the procedure.
5 days

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.
Provincial Headquarter Teaching Hospital Gilgit

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: Khawar Suliman, MBBS, FCPS, Provincial Headquarter Teaching Hospital Gilgit

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, 2022

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.
April 30, 2026

Study Completion (Actual)

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.
June 30, 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).
August 14, 2026

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.
August 14, 2026

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.
August 18, 2026

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.
August 18, 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.
August 14, 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

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.
  • PHQ01

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

Individual participant data will not be shared with other researchers due to institutional policies regarding patient confidentiality and data protection. Additionally, the trial is a single-center study with a modest sample size, and the research team does not have an established infrastructure for data-sharing or the necessary resources to support external data requests.

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.

Cookie Settings

We use cookies to ensure that we give you the best experience on our website. For more details carefully read our Privacy and Cookies Policy. ...>>>You can change your preferences or withdraw your consent at any time by deleting the cookies from your website or computer as described in the policy. Please accept it and choose your preferences by ticking the corresponding boxes in the "Manage Settings" section below. Please carefully read our Terms of Service before you proceed with using any part of this website.
«Manage Settings