Tissue Sensor for Semirigid Thulium Fiber Laser Ureterolithotripsy

NCT07835113 | Not Yet Recruiting

• 1 other identifier: MoscowBotkinHospital2
• Study Type: interventional
• Target: 121
• Locations: 0 countries
• Sites: N/A

Brief Summary

Tissue Sensor (TS) is a technology designed to automatically deactivate laser emission when contact between the laser fiber and tissue is detected. It is hypothesized that the use of TS during contact laser ureterolithotripsy may reduce unintended laser exposure of the ureteral mucosa, thereby decreasing the risk of immediate thermal injury to the ureteral wall and subsequent scar-related narrowing. To reduce the influence of baseline risk factors for stricture, the study will enroll a homogeneous population of patients without urinary tract anomalies, previous surgery on the study ureter, or impacted stones. The procedure will be performed according to a standardized protocol using a semirigid ureteroscope, a thulium fiber laser, and predefined technical restrictions. The study is limited to patients with stones in the mid or distal ureter. This approach is intended to minimize the likelihood of stone retropulsion into the kidney, standardize the surgical technique, reduce the need for conversion to flexible ureteroscopy, and maximize comparability between the study groups.

Conditions

Nephrolithiasis

Outcome Measures

Primary Outcomes (1)

• Incidence of intraoperative laser-induced injury to the ureteral mucosa

  Incidence of intraoperative laser-induced injury to the ureteral mucosa, defined as any visible injury compatible with exposure to an activated laser fiber, as determined by independent blinded video assessment.

  intraoperative

Secondary Outcomes (1)

• Incidence of postoperative ureteral stricture

  12 months.

Study Arms (2)

Patients after ureterolithotrypsy with Tissue Sensor activated

EXPERIMENTAL

Semirigid TFL ureterolithotripsy will be performed with Tissue Sensor activated. All automatic system trigger events will be recorded by the laser system or in the study case report form and, whenever possible, synchronized with the procedure video recording

Procedure: Semirigid TFL ureterolithotripsy with Tissue Sensor activated.

Patients after ureterolithotrypsy with Tissue Sensor deactivated

EXPERIMENTAL

Semirigid TFL ureterolithotripsy will be performed with Tissue Sensor deactivated. Visually confirmed contacts between the activated laser fiber and the ureteral mucosa will be recorded from the procedure video

Procedure: Semirigid TFL ureterolithotripsy with Tissue Sensor deactivated.

Interventions

Semirigid TFL ureterolithotripsy with Tissue Sensor activated. PROCEDURE

Semirigid TFL ureterolithotripsy will be performed with Tissue Sensor activated. All automatic system trigger events will be recorded by the laser system or in the study case report form and, whenever possible, synchronized with the procedure video recording

Patients after ureterolithotrypsy with Tissue Sensor activated

Semirigid TFL ureterolithotripsy with Tissue Sensor deactivated. PROCEDURE

Semirigid TFL ureterolithotripsy will be performed with Tissue Sensor deactivated. Visually confirmed contacts between the activated laser fiber and the ureteral mucosa will be recorded from the procedure video.

Patients after ureterolithotrypsy with Tissue Sensor deactivated

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Age 18 years or older.
• A single stone in the mid or distal ureter.
• Maximum stone diameter of 15 mm or less on preoperative CT.
• An indication for elective semirigid laser ureterolithotripsy.
• Feasibility of performing the procedure with a semirigid ureteroscope.
• No active urinary tract infection at the time of the intervention.
• Ability to undergo CT follow-up and complete 12 months of follow-up.
• Signed written informed consent.

You may not qualify if:

• Age 18 years or older.
• A single stone in the mid or distal ureter.
• Maximum stone diameter of 15 mm or less on preoperative CT.
• An indication for elective semirigid laser ureterolithotripsy.
• Feasibility of performing the procedure with a semirigid ureteroscope.
• No active urinary tract infection at the time of the intervention.
• Ability to undergo CT follow-up and complete 12 months of follow-up.
• Signed written informed consent.

Sponsors & Collaborators

• Botkin Hospital: lead

MeSH Terms

Conditions

Nephrolithiasis

Condition Hierarchy (Ancestors)

Kidney Diseases; Urologic Diseases; Female Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Urogenital Diseases; Urolithiasis; Male Urogenital Diseases

Central Study Contacts

Nikita Astakhov

CONTACT

+8 (968) 490-46-72; astakhov.nikita@inbox.ru

Vigen Malkhasyan, Doctor of Medical Sciences

CONTACT

+79096441688; botkinhospital@zdrav.mos.ru

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Doctor of medical science

Study Record Dates

• First Submitted: September 17, 2026
• First Posted: September 22, 2026
• Study Start: October 1, 2026
• Primary Completion (Estimated): October 1, 2028
• Study Completion (Estimated): November 2, 2028
• Last Updated: September 22, 2026

Record last verified: 2026-09