Super-Pulsed Thulium Fiber Laser Versus Holmium:YAG Laser in Retrograde Intrarenal Surgery for Upper Ureteral and Renal Stones

Not Applicable

Not yet recruiting

• Conditions: Ureterolithiasis; Renal Calculi

• Registration Number: NCT07012941
• Lead Sponsor: Sun Yat-Sen Memorial Hospital of Sun Yat-Sen University

Brief Summary

The holmium laser is currently considered the gold standard for lithotripsy on urinary lithiasis, whereas the super-pulsed thulium fibre laser is a relatively new technology. Through a multi-center prospective randomised clinical study that mainly aims to explore the effectiveness and safety of a super-pulsed fibre thulium laser compared to a holmium laser in the treatment of upper ureteral and renal stones (10mm\<cumulative maximum diameter ≤ 25mm) in retrograde intrarenal surgery. The research participants are assigned randomly to undergo retrograde intrarenal surgery (RIRS) either using a super-pulsed thulium fibre laser or a holmium-YAG laser with an allocation ratio of 1:1. The secondary aim of this study is to provide high-level evidence for the development of diagnostic and treatment guidelines in the field of urolithiasis, both domestically and internationally. The outcomes of the RIRS procedures are compared for the two treatment arms.

Detailed Description

Endoscopic surgery is the predominant method for treating urinary tract stones. The field of surgery has progressed from traditional open procedures and percutaneous lithotripsy to more advanced techniques such as mini, micro, and ureteroscopy methods. RIRS, which stands for retrograde intrarenal surgery, is a therapeutic option for upper ureteric or renal stones that are less than 2cm. Although various energy systems have been employed for stone fragmentation during ureteroscopy, laser energy is the predominant method used for this purpose. Both domestic and foreign criteria recommend the holmium laser. The thermal effects of the Ho:YAG laser efficiently pulverise stones. As a result, it is currently the most widely used laser for conducting laser lithotripsy on stones in the urinary tract. Unfortunately, the holmium-YAG laser system has some intrinsic problems, such as different components having varying effects. 2. During the fragmentation process, the stone displacement is large and difficult to accurately control. 3. Some stones cannot be powdered, heat-damaged, or perforated. 4. Mucosal damage during fragmentation makes it easy to bleed and ooze. 5. The powdering efficiency is low, the fragmentation time is long, there is a lower energy conversion ratio, excessive heat generation in machines, noise, etc. Thus, clinical practice requires a new laser technology to overcome the holmium laser's limitations.

Thus, new laser systems are being created to fix the issue. The newest laser technology, super-pulsed thulium fiber laser (SPTFL), has promising results. A super-pulse fibre thulium laser is a pulsed fibre thulium laser that can be clinically used for lithotripsy. In 2005, in vitro experiments related to super-pulsed fibre thulium laser lithotripsy were first reported. Experimental data suggests that, compared with holmium laser, thulium laser has the following advantages in urinary tract stone lithotripsy: 1. TFL has higher lithotripsy efficiency, and the stone ablation speed is 1.5-4 times faster than that of Ho:YAG. 2. A safer lithotripsy with a 4-fold reduction in penetration depth and a limited temperature increase inside the cavity (up to 39 °C). 3. Lower costs: low maintenance costs, low fibre damage, low equipment volume (1/8), high energy conversion. Subsequently, an increasing number of in vitro experiments and clinical studies have been conducted internationally. However, there is a scarcity of studies in the literature that directly compare the effectiveness and stone free rates of the Holmium-YAG laser and SPTFL systems. Consequently, investigators are interested in conducting a formal multi-center prospective randomised clinical study to compare the two systems in RIRS.

Study Timeline

• Study First Submitted: 2025-05-20
• Status Verified: 2025-06
• Study First Submitted QC: 2025-06-09
• Last Update Submitted: 2025-06-09
• Study First Posted: 2025-06-10
• Last Update Posted: 2025-06-10
• Study Start: 2025-07-01
• Primary Completion: 2027-02-28
• Study Completion: 2027-03-20

Recruitment & Eligibility

• Status: NOT_YET_RECRUITING
• Sex: All
• Target Recruitment: 448

Inclusion Criteria

1. 18 ≤ Age ≤ 75 years old, regardless of gender, able to tolerate surgery;
2. Patients who have been confirmed by bilateral renal/urinary tract CT to have upper ureteral or renal stones, single or multiple, and are planning to undergo ureteroscopic lithotripsy for stone removal;
3. Confirmed by bilateral renal/urinary tract CT, the cumulative maximum diameter of stones is 10mm<cumulative maximum diameter ≤ 25mm;
4. Those who voluntarily participate and sign an informed consent form.

Exclusion Criteria

1. Uncontrollable systemic hemorrhagic disease;
2. Severe spinal deformities, severe hip joint deformities, and difficulty in lithotomy position;
3. Uncontrolled urinary tract infections;
4. Any intracavitary surgery caused by anatomical factors of the urinary system cannot be performed;
5. Pregnant, planned pregnancy within 3 months, and lactating female patients;
6. The patients determined by the investigator to be unsuitable for this study include (but are not limited to): known to have human immunodeficiency virus (HIV) or AIDS; Suffering from mental illness; Infectious diseases;

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Primary Outcome Measures

Name	Time	Method
Stone-Free Rate at 4 Weeks Postoperative (Percentage of Participants)	4 week post-operative	Urinary tract CT（Computed Tomography）scan at 4 weeks post-operative did not reveal residual stones or residual stones with a diameter ≤ 2 mm and no clinical symptoms were defined as stone clearance

Secondary Outcome Measures

Name	Time	Method
Intraoperative complication rate (Percentage of Participants)	During the procedure	Includes ureteral or renal pelvis perforation, mucosal avulsion, ureteral rupture, conversion to other treatments, and success rate of ureteral access sheath insertion.
Change in Serum Creatinine from Baseline (μmol/L)	Within 24 hours postoperative	Serum creatinine measured before and within 24 hours after surgery
Change in Hemoglobin from Baseline (g/dL)	Within 24 hours postoperative	Hemoglobin measured before and within 24 hours after surgery
Change in Blood Urea Nitrogen from Baseline (mmol/L)	Within 24 hours postoperative	BUN measured before and within 24 hours after surgery
Operative time (Minutes)	Decided immediately after the surgery	Duration of operation
Length of Hospital Stay (Days)	up to 30 days	Total number of days the participant is hospitalized for the surgical procedure, from the day of surgery until discharge
Total hospitalization costs	Up to 3 months	Total cost incurred during the participant's hospital stay for the surgical procedure, including all procedural and inpatient care charges
Postoperative Complications (Clavien-Dindo Classification, Percentage of Participants)	Up to 30 days post-operative	Postoperative complications, Recording data according to the Clavien-Dindo classification such as infection, pain, ureteral stricture and other complications that result in the need for intervention or readmission or surgical revision following the RIRS procedure.
Number of Additional Staged Procedures (Count per Participant)	Up to 3 months post-operation	Number of additional surgical procedures required due to incomplete stone clearance, based on imaging findings at the 4-week follow-up after the initial RIRS procedure
Lithotripsy time (Minutes)	intra-operation	Time spent performing laser lithotripsy

Trial Locations

Locations (1)

Sun Yat sen Memorial Hospital of Sun Yat sen University; 🇨🇳 Guangzhou, Guangdong, China