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

Completed

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Actual)

100

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 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

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
Intervention / Treatment
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

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

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

Provincial Headquarter Teaching Hospital Gilgit

Investigators

  • 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)

October 1, 2022

Primary Completion (Actual)

April 30, 2026

Study Completion (Actual)

June 30, 2026

Study Registration Dates

First Submitted

August 14, 2026

First Submitted That Met QC Criteria

August 14, 2026

First Posted (Actual)

August 18, 2026

Study Record Updates

Last Update Posted (Actual)

August 18, 2026

Last Update Submitted That Met QC Criteria

August 14, 2026

Last Verified

July 1, 2026

More Information

Terms related to this study

Keywords

Other Study ID 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.

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