Thulium Fiber Laser (TFL) vs Thulio Pulsed Thulium:YAG (p-Tm:YAG)

August 1, 2025 updated by: Roger L Sur, M.D., University of California, San Diego

Prospective Single-center Study Comparing Thulium Fiber Laser to Pulsed Thulium:YAG Laser in the Ureteroscopic Treatment of Nephrolithiasis

This research study is being conducted to assess the ability and efficiency of two laser systems to break up kidney stones during ureteroscopy with laser lithotripsy for kidney stone treatment.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

Ureteroscopic stone treatment is a minimally invasive procedure commonly performed for kidney stones. Recently, the thulium fiber laser (TFL) has demonstrated effectiveness in this procedure. A new laser system developed by Dornier, the Thulio pulsed Thulium:YAG (p-Tm:YAG ) is beginning to be studied in vitro and in vivo. Dornier Thulio p-Tm:YAG may represent an attractive new laser platform, with comparable properties to TFL including decreased retropulsion, smaller dust, and improved ablation efficiency relative to Ho:YAG. Moreover, the p-Tm:YAG laser has been shown to be effective in treating a wide range of human stone types. The Dornier Thulio p-Tm:YAG laser has been tested clinically in a limited fashion via pilot studies in URS and the RevoLix Hybrid Thulium Laset (HTL) was studied in mini-PCNL. However, limited research has directly compared its efficacy and safety and no prospective comparative trials have been published.

This study aims to investigate whether Dornier Thulio p-Tm:YAG laser is non-inferior to TFL in terms of dusting ablation efficiency (J/mm3) and dusting ablation speed (mm3/s) for ureteroscopic stone treatment. To our knowledge no large-scale study has examined the outcomes of p-Tm:YAG compared to TFL for the treatment of kidney stones which warrants an investigation giving the promising results previously reported.

The primary objective is to assess stone dusting ablation efficiency (Joules/stone volume ablated) between both laser systems in vivo for ureteroscopic stone treatment . Secondary objectives include assessing stone dusting ablation speed (stone volume ablated/lasing time) and complication profile of both laser systems.

The investigators hypothesize that dusting ablation efficiency and speed of the p-Tm:YAG laser will be non-inferior to TFL for the treatment of renal stones totaling 7-20 mm in diameter with similar clinical and safety/complication outcomes.

Study Type

Interventional

Enrollment (Estimated)

50

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

  • United States
    • California
      • San Diego, California, United States, 92122
        • Recruiting
        • University of California, San Diego
        • Contact:
        • Contact:
        • Principal Investigator:
          • Roger L Sur, MD

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:

  • Solitary renal stone 7 to 20 mm in size or in the case of multiple stones the conglomerate diameter (additive maximal diameter of all stones on axial imaging of computed tomography) of 7-20 mm is required
  • Must be a suitable operative candidate for flexible ureteroscopy per American Urological Association guidelines
  • Must be able to give consent
  • Bilateral ureteroscopy will be permitted but only the first side (per surgeon discretion) will be included in the study
  • Surgeons participating in the study must be urological attending surgeons or fellows with subspecialty training in Endourology

Exclusion Criteria:

  • Concomitant stones in the ureter
  • Prior ipsilateral upper urinary tract reconstructive procedures or history of ipsilateral ureteral stricture
  • Prior radiotherapy to the abdomen or pelvis
  • Neurogenic bladder or spinal cord injury
  • Pregnancy
  • Untreated UTI

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: Single

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: p-Tm:YAG laser system
This is a new laser system developed by Dornier, the Thulio pulsed Thulium:YAG (p-Tm:YAG)
Device: Thulio pulsed Thulium:YAG (p-Tm:YAG)
A new laser system developed by Dornier, the Thulio pulsed Thulium:YAG (p-Tm:YAG ) is beginning to be studied in vitro and in vivo. Dornier Thulio p-Tm:YAG may represent an attractive new laser platform, with comparable properties to TFL including decreased retropulsion, smaller dust, and improved ablation efficiency relative to Ho:YAG.
Active Comparator: TFL laser system
The thulium fiber laser (TFL) has demonstrated effectiveness in this procedure.
Device: Thulium Laser Fiber (TFL)
The thulium fiber laser (TFL) has demonstrated effectiveness in this procedure

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
The amount of energy used per given stone volume
Time Frame: From enrollment to the follow up imaging at 6-12 weeks
The primary object is to assess the stone dusting ablation efficiency - efficiency will be defined by amount of laser energy used per stone volume (Joules/mm3)
From enrollment to the follow up imaging at 6-12 weeks

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Laser ablation speed (volume of stone/lasing time = mm3/sec)
Time Frame: From enrollment to the follow up imaging at 6-12 weeks
Secondary objectives include assessing stone dusting ablation speed. This is assessed by taking the stone volume ablated (mm3) and dividing it by lasing time (seconds) - mm3/sec.
From enrollment to the follow up imaging at 6-12 weeks
Post-operative complications compared between the two laser systems
Time Frame: From enrollment to the follow up imaging at 6-12 weeks
Secondary objectives include assessing post-operative complications. This is defined as the proportion of post-operative infections, readmissions to the hospital, and unplanned procedures compared between the two laser systems.
From enrollment to the follow up imaging at 6-12 weeks

Collaborators and Investigators

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

Sponsor

University of California, San Diego

Collaborators

Dornier MedTech Systems

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)

August 1, 2024

Primary Completion (Estimated)

August 1, 2026

Study Completion (Estimated)

December 31, 2026

Study Registration Dates

First Submitted

November 25, 2024

First Submitted That Met QC Criteria

December 3, 2024

First Posted (Actual)

December 6, 2024

Study Record Updates

Last Update Posted (Actual)

August 3, 2025

Last Update Submitted That Met QC Criteria

August 1, 2025

Last Verified

August 1, 2025

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 810115
  • 314954-00001 (Other Grant/Funding Number: Dornier MedTech)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

Yes

product manufactured in and exported from the U.S.

Yes

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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