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

Official title

An Application of Super-pulsed TFL vs Ho:YAG Laser in Retrograde Intrarenal Surgery for Upper Ureter and Renal Stones: A Multi-center Prospective Randomized Controlled Trial

Overview

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.

Interventions

• Device Superpulse Thulium Fiber laser (SPTFL) ureteroscopy for treatment of upper urinary tract stone or renal stone
  RIRS procedure for upper ureteral or renal stone lithotripsy with Superpulsed Thulium Laser
• Device Holmium: YAG laser ureteroscopy for treatment of upper urinary tract stone or renal stone
  RIRS procedure for upper ureteral or renal stone lithotripsy with Holmium: YAG Laser

Primary outcome measures

• Stone-Free Rate at 4 Weeks Postoperative (Percentage of Participants) [Time frame: 4 week post-operative]

Secondary outcome measures (10)

• Intraoperative complication rate (Percentage of Participants) [Time frame: During the procedure]
• Change in Hemoglobin from Baseline (g/dL) [Time frame: Within 24 hours postoperative]
• Change in Serum Creatinine from Baseline (μmol/L) [Time frame: Within 24 hours postoperative]
• Change in Blood Urea Nitrogen from Baseline (mmol/L) [Time frame: Within 24 hours postoperative]
• Operative time (Minutes) [Time frame: Decided immediately after the surgery]
• Lithotripsy time (Minutes) [Time frame: intra-operation]
• Length of Hospital Stay (Days) [Time frame: up to 30 days]
• Total hospitalization costs [Time frame: Up to 3 months]
• Postoperative Complications (Clavien-Dindo Classification, Percentage of Participants) [Time frame: Up to 30 days post-operative]
• Number of Additional Staged Procedures (Count per Participant) [Time frame: Up to 3 months post-operation]

Eligibility criteria

Inclusion criteria

• 18 ≤ Age ≤ 75 years old, regardless of gender, able to tolerate surgery;
• 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;
• Confirmed by bilateral renal/urinary tract CT, the cumulative maximum diameter of stones is 10mm<cumulative maximum diameter ≤ 25mm;
• Those who voluntarily participate and sign an informed consent form.

Exclusion criteria

• Uncontrollable systemic hemorrhagic disease;
• Severe spinal deformities, severe hip joint deformities, and difficulty in lithotomy position;
• Uncontrolled urinary tract infections;
• Any intracavitary surgery caused by anatomical factors of the urinary system cannot be performed;
• Pregnant, planned pregnancy within 3 months, and lactating female patients;
• 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;

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Allocation

Randomized

Model

Parallel assignment

Masking

Single blind

Primary purpose

Treatment

Study locations

China · 1 center

• Sun Yat sen Memorial Hospital of Sun Yat sen University — Guangzhou

Publications

• Wang W, Fan J, Huang G, Li J, Zhu X, Tian Y, Su L. Prevalence of kidney stones in mainland China: A systematic review. Sci Rep. 2017 Jan 31;7:41630. doi: 10.1038/srep41630. PMID 28139722
• Khan SR, Pearle MS, Robertson WG, Gambaro G, Canales BK, Doizi S, Traxer O, Tiselius HG. Kidney stones. Nat Rev Dis Primers. 2016 Feb 25;2:16008. doi: 10.1038/nrdp.2016.8. PMID 27188687
• Fried NM, Irby PB. Advances in laser technology and fibre-optic delivery systems in lithotripsy. Nat Rev Urol. 2018 Sep;15(9):563-573. doi: 10.1038/s41585-018-0035-8. PMID 29884804
• Teichmann HO, Herrmann TR, Bach T. Technical aspects of lasers in urology. World J Urol. 2007 Jun;25(3):221-5. doi: 10.1007/s00345-007-0184-5. Epub 2007 May 30. PMID 17534625
• Emiliani E, Kanashiro A, Angerri O. Lasers for stone lithotripsy: advantages/disadvantages of each laser source. Curr Opin Urol. 2023 Jul 1;33(4):302-307. doi: 10.1097/MOU.0000000000001092. Epub 2023 Mar 17. PMID 36927702
• Traxer O, Keller EX. Thulium fiber laser: the new player for kidney stone treatment? A comparison with Holmium:YAG laser. World J Urol. 2020 Aug;38(8):1883-1894. doi: 10.1007/s00345-019-02654-5. Epub 2019 Feb 6. PMID 30729311
• Hale GM, Querry MR. Optical Constants of Water in the 200-nm to 200-microm Wavelength Region. Appl Opt. 1973 Mar 1;12(3):555-63. doi: 10.1364/AO.12.000555. PMID 20125343
• Ventimiglia E, Doizi S, Kovalenko A, Andreeva V, Traxer O. Effect of temporal pulse shape on urinary stone phantom retropulsion rate and ablation efficiency using holmium:YAG and super-pulse thulium fibre lasers. BJU Int. 2020 Jul;126(1):159-167. doi: 10.1111/bju.15079. Epub 2020 May 18. PMID 32277557

Identifiers

NCT: NCT07012941 · SYSKY-2024-050-01

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗