Presented by: Mark Taratkin M.D., urologist, researcher
Institute for Urology and Reproductive Health, Sechenov First Moscow State Medical University (Sechenov University) Moscow, Russian Federation

Introduction

The aims of the study were: 1) to compare the SuperPulsed Thulium fiber laser (SP TFL) and the Holmium YAG (Ho:YAG) laser for retrograde intrarenal surgery (RIRS) and 2) to compare the efficacy of using SP TFL laser fibers (LF) of different diameters (150 μm and 200 μm) for RIRS.

Materials

A prospective randomized single-blinded trial was conducted. Patients with stones from 10 to 20 mm were randomly assigned RIRS in three groups: (1) SP TFL (NTO IRE-Polus, Russia) with LF diameter of 150 μm; (2) SP TFL with 200 μm LF; and (3) Ho:YAG (Lumenis, USA) with 200-μm LF. The procedures were performed by 5 surgeons experienced in laser lithotripsy (>50 RIRS). Stone size, density, surgery length and laser on time (LOT) were measured. The stone-free rates (SFR) were assessed with a low-dose CT scan 90 days postoperatively.

Results

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Between January 2020 and October 2021, 96 patients with kidney stones were randomized to undergo RIRS with SP TFL using a 150-μm fiber (34 patients) and a 200-μm fiber (32 patients) and RIRS with Ho:YAG (30 patients). The median LOT was minimal in the group of SP TFL with 200-μm (9.2 (6.2 - 14.6) min. Similar results were found in SP TFL with 150-μm (11.4 (7.7 - 14.9) min, p=0.390) whilst a longer LOT was found in Ho:YAG (14.1 (10.8 - 18.1)) min, p=0.021). Similar findings were observed in total energy: SP TFL with 200-μm (8.4 (5.8-15.2) kJ; SP TFL using 150-μm (10.8 (7.3-13.5) kJ, p=0.626) and in Ho:YAG (15.2 (11.1-25.3) kJ, p=0.005). The duration of the surgery was shortest in SP TFL with 150-μm (60.2±20.1 min) which was shorter than that of SP TFL with 200-μm (74.4±26.3 min, p=0.044). Both durations were shorter than that of Ho:YAG (90.0±31.8 min, p=0.006).

The SFR at 3 months was 100% (no fragments larger than 2 mm were observed). The postoperative complication rate was low, with grade I-II Clavien-Dindo complications present in 2 (2.1%) patients. No differences were found between the groups.

Conclusion

Irrespective of the stone type and density, RIRS with SP TFL laser is a safe and efficient procedure. Whilst the introduction of smaller fibers may have the potential to reduce the duration of surgery, SP TFL results in a reduction in the LOT and total energy for stone ablation in RIRS compared with Ho:YAG. The stone free rate and complication rates were comparable between the lasers.

 

Funding

the study is deprived of funding

Lead Authors

Dmitry Enikeev, M.D., PhD, Prof.; Adjunct Prof.,
Institute for Urology and Reproductive Health, Sechenov First Moscow State Medical University (Sechenov University);., Department of Urology and Comprehensive Cancer Center, Medical University of Vienna

Co-Authors

Camilla Azilgareeva, student
Sklifosovsky Institute for Clinical Medicine, Sechenov First Moscow State Medical University (Sechenov University)

Vladislav Petov, urologist, researcher
Institute for Urology and Reproductive Health, Sechenov First Moscow State Medical University (Sechenov University)

Andrey Morozov, M.D., PhD, urologist, senior researcher
Institute for Urology and Reproductive Health, Sechenov First Moscow State Medical University (Sechenov University)

Diana Babaevskaya, student
Sklifosovsky Institute for Clinical Medicine, Sechenov First Moscow State Medical University (Sechenov University)

Dmitry Korolev Korolev,
Institute for Urology and Reproductive Health, Sechenov First Moscow State Medical University (Sechenov University)

Stanislav Ali,
Institute for Urology and Reproductive Health, Sechenov First Moscow State Medical University (Sechenov University)

Vincent De Coninck,
Department of Urology, AZ Klina

Gagik Akopyan1,
Institute for Urology and Reproductive Health, Sechenov First Moscow State Medical University (Sechenov University)

Cesare Marco Scoffone,
Department of Urology, Cottolengo Hospital

Denis Chinenov,
Institute for Urology and Reproductive Health, Sechenov First Moscow State Medical University (Sechenov University)

Alexander Androsov,
Sklifosovsky Institute for Clinical Medicine, Sechenov First Moscow State Medical University (Sechenov University)

Harun Fajkovic,
5Department of Urology, Medical University of Vienna

David Lifshitz,
8Sackler School of Medicine, Tel-Aviv University

Olivier Traxer,
GRC #20 Lithiase Urinaire, Sorbonne University, Hôpital Tenon