Abstract
Objective
Flexible ureteroscopy (fURS) has become a widely accepted and effective technique for treating kidney stones. With the development of new laser systems, the fURS approach has evolved significantly. This literature review aims to examine the current state of knowledge on fURS treatment of kidney stones, with a particular focus on the impact of the latest laser technologies on clinical outcomes and patient safety.
Methods
We conducted a search of the PubMed/PMC, Web of Science Core Collection, Scopus, Embase (Ovid), and Cochrane Databases for all randomized controlled trial articles on laser lithotripsy in September 2023 without time restriction.
Results
We found a total of 22 relevant pieces of literature. Holmium laser has been used for intracavitary laser lithotripsy for nearly 30 years and has become the golden standard for the treatment of urinary stones. However, the existing holmium laser cannot completely powder the stone, and the retropulsion of the stone after the laser emission and the thermal damage to the tissue have caused many problems for clinicians. The introduction of thulium fiber laser and Moses technology brings highly efficient dusting lithotripsy effect through laser innovation, limiting pulse energy and broadening pulse frequency.
Conclusion
While the holmium:yttrium-aluminum-garnet laser remains the primary choice for endoscopic laser lithotripsy, recent technological advancements hint at a potential new gold standard. Parameter range, retropulsion effect, laser fiber adaptability, and overall system performance demand comprehensive attention. The ablation efficacy of high-pulse-frequency devices relies on precise targeting, which may pose practical challenges.
Keywords: Laser lithotripsy, Urolithiasis, Thulium laser, Holmium:yttrium--aluminum-garnet, Moses effect
1. Introduction
In the field of urology, the introduction of lithotripsy lasers in 1968 marked a significant milestone. However, early models that operated in continuous mode, such as ruby, neodymium-doped yttrium-aluminum-garnet, and CO2 lasers [1], were not suitable for endoscopic laser lithotripsy (ELL) due to significant soft tissue heat injury. In the 1990s, the emergence of flexible fiberoptic ureteroscopes revolutionized endoscopic stone treatment. The resulting flexible ureteroscopy (fURS) approach has demonstrated outstanding clinical performance and safety since its inception. The availability of disposable ureteroscopes has further transformed the field [2].
Expanding upon the invention of fURS, the age of endoscopic lithotripsy using pulsed laser began [3]. Holmium:yttrium-aluminum-garnet (Ho:YAG) laser, operating at a wavelength of 2120 nm, has been the preferred laser platform for intracorporeal endoscopic stone lithotripsy since the 1900s and is considered the gold standard by several international recommendations [4]. In 1994, the Moses concept was developed to divide a single pulse into two smaller ones, each with a distinct peak strength. Lumenis (Lumenis Ltd., Yokneam, Israel) has recently introduced Moses 2.0, a new version of high-power (HP) laser that can operate at 120 Hz [5]. Nevertheless, whether this type of technology is superior to the standard low-power Ho:YAG laser remains unknown. The most recent laser technology for stone lithotripsy is thulium fiber laser (TFL). Although it was initially used for this purpose in an in vitro research in 2005, it has drawn more interest for its potential application in clinical settings. Despite these advancements, a comprehensive evaluation remains limited, partly due to the sudden spike in interest in a short period of time [6].
There will be a significant increase in the use of disruptive technologies in clinical practice, such as real-time intrarenal pressure, temperature management, and autonomous laser lithotripsy. These advances could revolutionize endoscopic stone treatment by taking fURS to a new level. This study aimed to review the most recent laser technology for endoscopic lithotripsy and describe the impact of these new laser systems on our clinical processes.
2. Methods
A literature review was carried out in September 2023 using PubMed/PMC, Web of Science Core Collection, Scopus, Embase (Ovid), and Cochrane databases. All randomized controlled trials with Ho:YAG, Moses technology, and TFL were included in the present study. Different searches were performed with the following Medical Subject Heading terms or keywords: “randomized controlled trial”, “holmium”, “thulium”, “laser”, “Moses”, “urolithiasis”, “lithotripsy”, “endourology”, “stones”, and “lithiasis”. Boolean operators (AND, OR) were used to refine the search. There was no time limit restriction (Table 1).
Table 1.
Summary of included studies.
| Study |
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Moses 1.0 | |||||
| Haas et al., [47] 2023 |
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| Ulvik et al., [45] 2022 |
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| Shrestha et al., [52] 2022 |
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| Martov et al., [53] 2021 |
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| Karakoyunlu et al., [54] 2021 |
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| Abdelbary et al., [55] 2021 |
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| Alghamdi et al., [56] 2020 |
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| Lu et al., [57] 2020 |
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| Ibrahim et al., [58] 2020 |
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| Jiang et al., [59] 2019 |
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| Jin et al., [60] 2019 |
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| EL-Nahas et al., [61] 2016 |
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| Li et al., [62] 2015 |
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| Kumar et al., [63] 2015 |
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| Cimino et al., [64] 2014 |
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| Ganesamoni et al., [65] 2013 |
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| Razzaghi et al., [66] 2013 |
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| Kassem et al., [67] 2012 |
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| Zhang et al., [68] 2011 |
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| Binbay et al., [69] 2011 |
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| Garg et al., [70] 2009 |
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| Arrabal-Polo et al., [71] 2009 |
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Pt, patient; Ho:YAG, holmium:yttrium-aluminum-garnet; TFL, thulium fiber laser; SFR, stone-free rate; URS, ureteroscopy; HU, Hounsfield unit; fURL, flexible ureteroscopic lithotripsy; PCNL, percutaneous nephrolithotomy; Hp-Hll, high-power holmium laser lithotripsy; Us-L, ultrasonic lithotripsy; LU, laparoscopic ureterolithotomy; PL, pneumatic lithotripsy; LL, laser lithotripsy; SWL, shock wave lithotripsy; SP, super pulse; HP, high-power; LP, low-power; Hb, hemoglobin; RIRS, retrograde intrarenal surgery; ESWL, extracorporeal SWL; fURS, flexible ureteroscopy; NA, not available.
We focused on all studies that include flexible ureteroscopic treatment for ureteral and kidney stones using the mentioned technology. Exclusion criteria included the use of the above laser systems in a non-endoscopic lithotripsy context, studies performed exclusively on pediatric patients, and non-English articles. Additionally, conference papers, abstracts, editorials, and letters were excluded. In sum, 22 relevant papers were included in our literature review. Our paper selection process is summarized in Fig. 1. Due to the relative novelty, heterogeneity, and sparsity of available literature on TFL and Moses technology, our findings are presented as a narrative literature review.
Figure 1.
Flowchart illustrating literature review. Ho:YAG, holmium:yttrium-aluminum-garnet; TFL, thulium fiber laser.
3. Ho:YAG
3.1. Ho:YAG laser in history
Conceived in 1917, laser technology has significantly evolved over the past six decades [[7], [8], [9]]. While continuous-mode lasers were found unsuitable for lithotripsy due to excessive heat generation [10], pulsed lasers, such as the Ho:YAG laser [12,13], emerged as highly effective tools for stone lithotripsy.
Since the 1990s, the Ho:YAG laser has been the gold standard for ELL, being extensively researched in urology [1]. Teamed with modern ureteroscopes, its small and flexible laser fibers became indispensable tools for urinary stone fragmentation [15,16]. Following the initial results of holmium laser lithotripsy in 1995 [17], ongoing research has focused on optimizing power levels for efficient stone fragmentation [18,19]. The Ho:YAG laser exhibits versatility in ablating various urinary stone types, owing to its adjustable power settings and a high absorption peak in water at a wavelength of 2140 nm, closely matching the water's absorption peak at 1940 nm, a crucial component in most calculi [14].
3.2. Development of Ho:YAG laser in high energy
Theoretically, increasing power provides both high-energy and high-frequency exploration directions, but in vitro tests have shown that high energy (>0.6 J), while ensuring lithotripsy efficiency, also leads to stone retropulsion and larger fragments. It has been pointed out that it is the pulse energy, not the average power, that is positively correlated with the fragment size. In addition, the fiber loss in the high-energy setting (0.6–1.0 J) is significantly higher than that in the low-energy group (0.2–0.3 J), which is attributed to the microfracture caused by damage to the tip of the fiber in the contact fragmentation, and the high energy is more prone to the thermal mirror effect, which changes the spatial beam profile at the tip [7,8].
Ho:YAG lasers have demonstrated superior stone fragmentation capabilities compared to pulsed-dye lasers, pneumatic lithotripsy, and electro-hydraulic lithotripsy, owing to their ability to generate smaller stone fragments and their compatibility with small, flexible glass fibers, rendering them widely applicable [20]. Moreover, Ho:YAG lasers have been proven safe and efficient for use in ureteroscopy and percutaneous nephrolithotomy [21]. The photo-thermal mechanism of the holmium laser ensures safety during lithotripsy by minimizing urinary calculus migration, known as stone retropulsion, while reducing the risk of scatter damage to adjacent tissue and endoscopic equipment [[22], [23], [24], [25]].
3.3. Thermal injury of Ho:YAG laser
Despite the introduction of increasingly potent and high-frequency Ho:YAG lithotripters over the years, significant collateral thermal injury to soft tissue and restrictions in fiber-optic delivery of Ho:YAG have limited the applicability of flexible ureteroscope lithotripsy. The study by Aldoukhi et al. [9] has shown that temperature increased with increasing laser power output and decreasing the irrigation flow rate. The highest temperature, 70.3 °C (standard deviation 2.7 °C), occurred with laser setting of 1.0 J and 40 Hz and no irrigation after 60 s of continuous laser firing. None of the tested laser settings and irrigation parameters produced a temperature exceeding 51 °C when activated for only 10 s of continuous laser firing [9].
HP holmium settings fired in long bursts with low irrigation flow rates can generate high fluid temperatures. Being aware of this risk empowers urologists to employ various techniques, such as increasing irrigation flow rates, employing intermittent laser activation, and potentially using cooled irrigation fluid, to manage and mitigate thermal effects during holmium laser lithotripsy.
3.4. Exploration of Ho:YAG laser
At this stage, the high-frequency exploration of Ho:YAG seems to have encountered a bottleneck. The blind pursuit of Ho:YAG pulse frequency did not lead to an absolute increase in fragmentation efficiency, and the results of Aldoukhi et al. [10] showed that there was a threshold (61.6 Hz) at which the fragmentation efficiency did not increase with increasing frequency.
The Moses effect is a recent addition to the Lumenis Pulse P120H holmium laser system (Lumenis Ltd., Yokneam, Israel) that optimizes the transmission of energy from the laser fiber to the targeted tissue [11]. Due to the fact that the 2140 nm holmium infrared laser wavelength is highly absorbed by water (water absorption coefficient of 3198 L/m), the water absorbed energy contributes to the formation of a vapor microbubble at the laser's tip that grows towards the target [12,13]. Once the microbubble reaches the target, the laser beam can travel through the vapor to the target with minimal attenuation, as the density of water molecules in the vapor state is far lower than in the liquid form [14,15]. This substantial water absorption at the specified wavelength is responsible for an optical penetration depth of approximately 400 mm, making Ho:YAG appropriate for incision and coagulation of soft tissue.
4. Moses technology
4.1. Moses 1.0 clinical experience
The demand for a more effective laser lithotripsy has stimulated research in two primary directions: the creation of novel laser sources and the enhancement of energy delivery of Ho:YAG. For these reasons, a novel pulse modality was marketed in 2017—the Moses technology (Lumenis®, Yokne'am Illit, Israel), which takes advantage of a physical phenomenon called the “Moses effect”. Moses effect intrinsic qualities prompted the development of Moses™ technology. The purpose of this apparatus is to modulate the laser pulse from a Ho:YAG energy source into two components, the first of which is used to separate the water between the laser tip and the target (e.g., the stone), while the second delivers the energy directly to the target without significant energy loss [16]. Moses technology has two distinct modes of operation: a contact mode (Moses A) and a distance mode (Moses B). Both Moses A and B are suggested for lithotripsy, the first at a 1 mm distance and the second at a 2 mm distance [17].
In vitro research has shown that Moses technology reduces stone retropulsion significantly and reduces procedural time, resulting in a more effective lithotripsy compared to conventional fragmentation [12,17]. However, in a more recent in vivo investigation, Knoedler and colleagues [18] found that there was no significant effect between Moses and regular modes on the mean (standard deviation) procedural time (43.5±32.1 min vs. 39.8±24.6 min, p=0.436), fragmentation or dusting time (20.5±25.3 min vs. 17.1±16.1 min, p=0.430), lasering time (7.5±11.1 min vs. 6.7±7.9 min, p=0.570), or total energy consumed (5.1±6.7 kJ vs. 3.8±4.8 kJ, p=0.093). In addition, there were no differences in the incidence of complications or absence of stones.
There may be technological advantages of the Moses technology that are not accounted for in this research [18]. For example, Aldoukhi et al. [19] demonstrated that Moses distance is better than other modalities for stone fragmentation when employed in touch with the target or at a distance of 1 mm. Winship et al. [20] found no significant difference in ablation between 0 and 2 mm distance; however, at 1 mm, Moses distance caused much more ablation than all other settings. On hard stones, no pulse type appeared to be more advantageous than another [20].
In terms of thermal harm, Moses technology appears to have a lesser impact than other YAG lasers since it generates much lower temperatures; this might be an essential advantage given the long-term effect of heat generation during laser lithotripsy [21,26]. Using the configuration of a stone simulator, Moses technology is connected with more efficient laser lithotripsy (shorter operative time) as a result of dramatically decreased stone retropulsion. A prospective, blinded, randomized clinical investigation was undertaken to confirm the enhanced efficacy of the Moses technology, which showed the Moses contact mode was associated with significantly shorter procedural time during fragmentation (13.9 min vs. 9.1 min, p≤0.01) and dusting (9.3 min vs. 7.1 min; p≤0.01) compared to regular modes [12].
In preclinical models, Moses technology appears to offer a number of advantages and benefits as compared to alternative pulse patterns, but clinical proof of a major impact that might transform everyday practice is still absent.
4.2. Moses 2.0 clinical experience
In 2020, Lumenis introduced the Moses 2.0 system with a Moses pulse tuned for an extended frequency rate of 80–120 Hz, delivering a multi-pulse as opposed to the conventional short or long pulse. Comparing Moses distance and Moses 2.0 with extended frequency rate settings, Moses 2.0 with extended frequency rate had a superior stone ablation volume than Moses distance at a stone distance of 0 mm [22]. This advantage, however, is lost when stone density is considered, revealing a more efficient popcorn lithotripsy and a larger fragmentation rate on just hard stones [23]. A noteworthy discovery is that the ablation rate and laser efficiency were greater when the laser fiber scanning rate was increased [23] (Table 2).
Table 2.
Differences between Moses 1.0 and Moses 2.0.
| Feature | Moses 1.0 | Moses 2.0 |
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| First description |
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| Definition |
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| Clinical implication |
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Majdalany and colleagues [24] compared Moses 1.0 with Moses 2.0 among 29 patients. The Moses 1.0 group lasted less time (10.4 min vs. 14.3 min) and spent almost two times less energy (6.4 kJ vs. 12.4 kJ) than the Moses 2.0 group. Rezakahn Khajeh et al. [5] conducted research detailing their initial experience with Moses 2.0 for stones around 1 cm in diameter. The stone-free rate (SFR), lasing duration, and total energy utilized were comparable to those in the Majdalany et al. [24] investigation. Rezakahn Khajeh and colleagues [5] reported in a recent in vivo study that early experience with Moses 2.0 for fURS renal stone dusting indicated successful and efficient laser lithotripsy in patients with renal stones <2 cm.
It is important to note that due to the limited number of patients in this series, Moses 2.0 cannot be conclusively compared to Moses 1.0 or other non-pulse-modulated holmium systems. Larger studies are necessary to provide a comprehensive evaluation of this technology.
5. TFL
Despite its revolutionary impact in urology, the Ho:YAG laser exhibits several notable limitations. For instance, Ho:YAG lasers cannot sustain fibers less than 150 μm in diameter, which may restrict the surgeon's ability to access lower pole calyces during pyeloscopy [25]. In addition, due to the water cooling needs of more recent HP Ho:YAG lasers, the generators have grown in size and complexity, making movement between separate operative rooms difficult [27].
The TFL is a novel laser type that has shown early promise and may offer several advantages over Ho:YAG lasers. Its mechanism of action involves the utilization of multiple electronically modulated laser diodes to excite the thulium ions for laser pumping, distinguishing it from Ho:YAG lasers, which rely on flash lamps for this purpose [28].
5.1. In vitro and in vivo studies on TFL
TFL has an exceptional ablation rate for all types of urinary stones. It offers the broadest and most adaptable set of parameters among urology laser lithotripters [29]. The laser beam emitted has a wavelength of 1940 nm, may be operated in continuous or pulsed mode, and is significantly more uniform and focused [30,31]. Theoretically, the specific wavelength of the TFL at 1940 nm would provide in a favorable safety profile due to the laser being more effectively absorbed by water. TFL has a 4- to 5-fold greater water absorption than Ho:YAG lasers and doubles that of thulium:YAG lasers [32]. Moreover, TFLs can be transmitted to fibers with a smaller core diameter (50–150 μm). Using TFLs, the utilization of smaller laser fibers during laser lithotripsy has been investigated in vitro [[33], [34], [35], [36]]. These experimental fibers, ranging from 50 μm to 150 μm, are substantially smaller than the smallest Ho:YAG laser fiber currently available, which is 200 μm [[37], [38], [39], [40]].
TFL temporal pulse distribution is more uniform than Ho:YAG laser distribution, resulting in evenly scattered energy throughout the laser pulse's duration [41]. The use of smaller, distinct bubble dynamics, and the temporal pulse profile of the TFL contribute to the laser lithotripsy and tissue ablation capabilities of this technology. TFL produces smaller bubbles than Ho:YAG, both in terms of length and width, and also produces a stream of numerous bubbles during a single laser pulse at all power settings; hence, the production and collapse of the bubble may reduce stone retropulsion [42,43].
5.2. In vivo studies on TFL
Given the novelty of TFL, the existing in vivo literature is limited. The randomized controlled trial study of Ulvik et al. [45] has demonstrated that TFL is more effective and fewer experienced intraoperative complications compared to Ho:YAG. In comparison to the Ho:YAG laser, the TFL has a higher SFR (Ho:YAG: 49%, TFL: 86%, p=0.001) and less tissue damage (Ho:YAG: 5%, TFL: 22%, p=0.014). Benefiting from the improvement of the retropulsion and rebound of the stone, TFL has a shorter operative time (Ho:YAG: 57 min, TFL: 49 min, p=0.008) [[44], [45], [46]]. However, the advantages of TFL in clinical practice could be controversial. The up-to-date randomized controlled trial study by Haas et al. [47] suggested no significant difference in the mean utereroscope time between TFL technology and Ho:YAG (Ho:YAG: 21.4 min, TFL: 19.9 min, p=0.60). There were no significant differences observed in the SFRs (Table 3) or complication rates between the two lasers.
Table 3.
Clinical experience with Laser technology.
| Study | Technique | Laser setting | Stone location, sizea (cm) | Lasing timea, min | Energya, kJ | SFR, % |
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| Majdalany et al., 2021 [24] |
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| Rezakahn Khajeh et al., 2021 [5] |
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| Ulvik et al., 2022 [45] |
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| Patil et al., 2022 [72] |
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| Knoedler et al., 2021 [18] |
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| Corrales et al., 2021 [46] |
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| Pietropaolo et al., 2021 [73] |
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SFR, stone-free rate; Ho:YAG, holmium:yttrium-aluminum-garnet; TFL, thulium fiber laser; NA, not available.
Values are presented as mean.
Early in vivo studies on the application of the TFL in soft tissue ablation have shown encouraging results, while the literature on the use of the TFL in urological soft tissue procedures is still restricted [48]. Further study using randomized controlled trials is warranted to access the full value of TFLs for both lithotripsy and soft tissue urologic surgery.
5.3. Exploration of TFL
The thulium laser fiber has a finer diameter, which is conducive to improving the ureteroscopic lithotripsy field of view; thulium laser lithotripsy has less stone displacement, which is conducive to reducing postoperative complications, such as tissue thermal injury; the thulium laser fiber is also finer, which is conducive to increasing the curvature of the flexible ureteroscope, and may perhaps be used in the future for the treatment of stones with a small pelvic funnel pinch and a long calyceal neck [49]. Most of the heat of thulium laser lithotripsy is absorbed by water, which causes less thermal damage to tissue compared with holmium laser.
However, thulium lasers do exhibit some limitations and there are still few clinical studies. Theoretically, the power of a thulium laser can reach more than 2000 Hz, but in practice, the power of >300 Hz has greater thermal damage to the tissue, so it needs to be used with great caution [50,51]. Another problem with thulium laser powdering is that it is difficult to collect large stones for stone analysis. In addition, there is a gap in research on the cost of thulium laser lithotripsy. In the future, thulium laser lithotripsy with its high pulse energy and fine optical fiber will certainly occupy a place in the field of stone treatment. However, the clinical application of thulium laser is still in the exploratory stage, and more comparative studies between thulium laser and holmium laser are needed to further discover the advantages of thulium laser.
6. Conclusion
The advancements in the development of new lasers for urinary stone treatment have profoundly propelled the field forward. Presently, the Ho:YAG laser stands as the preeminent option for ELL. Nevertheless, recent technological breakthroughs have yielded promising outcomes, hinting at the potential emergence of a new gold standard. In addition to the pulse frequency parameter, comprehensive attention should be devoted to other attributes of each new laser system, encompassing the expanded parameter range, retropulsion effect, laser fiber adaptability, and the overall performance of the laser machine. Notably, it is crucial to recognize that the ablation efficacy of high-pulse-frequency devices attains maximum efficiency when placed directly on the target surface, which may not be consistently achievable in practical settings.
Author contributions
Study concept and design: Liang Zhou, Kunjie Wang.
Data acquisition: Simin Yu, Banghua Liao, Linhu Liu, Ya Li, Liang Zhou, Jixiang Chen, Hong Li, Kunjie Wang.
Data analysis: Simin Yu, Banghua Liao, Linhu Liu, Ya Li, Liang Zhou, Jixiang Chen, Hong Li, Kunjie Wang.
Drafting of manuscript: Simin Yu.
Critical revision of the manuscript: Simin Yu, Banghua Liao, Linhu Liu, Ya Li, Liang Zhou, Jixiang Chen, Hong Li, Kunjie Wang.
Conflicts of interest
The authors declare no conflict of interest.
Acknowledgements
This study was supported by the 1.3.5 Project for Disciplines of Excellence, West China Hospital, Sichuan University (Grant No. ZYGD18011 and No. ZYJC18015 to Wang K).
Footnotes
Peer review under responsibility of Tongji University.
References
- 1.Dretler S.P. Laser lithotripsy: a review of 20 years of research and clinical applications. Laser Surg Med. 1988;8:341–356. doi: 10.1002/lsm.1900080403. [DOI] [PubMed] [Google Scholar]
- 2.Marberger M., Hofbauer J., Türk C., Höbarth K., Albrecht W. Management of ureteric stones. Eur Urol. 1994;25:265–272. doi: 10.1159/000475300. [DOI] [PubMed] [Google Scholar]
- 3.Hofmann R., Hartung R. Laser lithotripsy of ureteral calculi. Urol Res. 1990;18(Suppl 1):S49–S55. doi: 10.1007/BF00301529. [DOI] [PubMed] [Google Scholar]
- 4.Black K.M., Aldoukhi A.H., Ghani K.R. A users guide to holmium laser lithotripsy settings in the modern era. Front Surg. 2019;6:48. doi: 10.3389/fsurg.2019.00048. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 5.Rezakahn Khajeh N., Majdalany S.E., Ghani K.R. Moses 2.0 for high-power ureteroscopic stone dusting: clinical principles for step-by-step video technique. J Endourol. 2021;35:S22–S28. doi: 10.1089/end.2021.0682. [DOI] [PubMed] [Google Scholar]
- 6.Khusid J.A., Khargi R., Seiden B., Sadiq A.S., Atallah W.M., Gupta M. Thulium fiber laser utilization in urological surgery: a narrative review. Investig Clin Urol. 2021;62:136–147. doi: 10.4111/icu.20200467. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 7.Knudsen B.E. Laser fibers for holmium: YAG lithotripsy: what is important and what is new. Urol Clin. 2019;46:185–191. doi: 10.1016/j.ucl.2018.12.004. [DOI] [PubMed] [Google Scholar]
- 8.Kronenberg P., Traxer O. In vitro fragmentation efficiency of holmium:yttrium-aluminum-garnet (YAG) laser lithotripsy—a comprehensive study encompassing different frequencies, pulse energies, total power levels and laser fibre diameters. BJU Int. 2014;114:261–267. doi: 10.1111/bju.12567. [DOI] [PubMed] [Google Scholar]
- 9.Aldoukhi A.H., Ghani K.R., Hall T.L., Roberts W.W. Thermal response to high-power holmium laser lithotripsy. J Endourol. 2017;31:1308–1312. doi: 10.1089/end.2017.0679. [DOI] [PubMed] [Google Scholar]
- 10.Aldoukhi A.H., Black K.M., Hall T.L., Roberts W.W., Ghani K.R. Frequency threshold for ablation during holmium laser lithotripsy: how high can you go? J Endourol. 2020;34:1075–1081. doi: 10.1089/end.2020.0149. [DOI] [PubMed] [Google Scholar]
- 11.Becker B., Gross A.J., Ho Netsch C. Ho:YaG laser lithotripsy: recent innovations. Curr Opin Urol. 2019;29:103–107. doi: 10.1097/MOU.0000000000000573. [DOI] [PubMed] [Google Scholar]
- 12.Ibrahim A., Badaan S., Elhilali M.M., Andonian S. Moses technology in a stone simulator. Can Urol Assoc J. 2017;12:127–130. doi: 10.5489/cuaj.4797. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 13.Ventimiglia E., Traxer O. What is moses effect: a historical perspective. J Endourol. 2019;33:353–357. doi: 10.1089/end.2019.0012. [DOI] [PubMed] [Google Scholar]
- 14.Corsini C., de Angelis M., Villa L., Somani B.K., Pietropaolo A., Montorsi F., et al. Holmium:yttrium-aluminum-garnet laser with Moses: does it make a difference? Curr Opin Urol. 2022;32:324–329. doi: 10.1097/MOU.0000000000000979. [DOI] [PubMed] [Google Scholar]
- 15.Stern K.L., Monga M. The Moses holmium system-time is money. Can J Urol. 2018;25:9313–9316. [PubMed] [Google Scholar]
- 16.Trost D. 1994. Laser pulse format for penetrating an absorbing fluid.https://patents.google.com/patent/US5321715A/en [Accessed 03 November 2023] [Google Scholar]
- 17.Elhilali M.M., Badaan S., Ibrahim A., Andonian S. Use of the Moses technology to improve holmium laser lithotripsy outcomes: a preclinical study. J Endourol. 2017;31:598–604. doi: 10.1089/end.2017.0050. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 18.Knoedler M.A., Li S., Best S.L., Hedican S.P., Penniston K.L., Nakada S.Y. Clinical impact of the institution of Moses technology on efficiency during retrograde ureteroscopy for stone disease: single-center experience. J Endourol. 2021;36:65–70. doi: 10.1089/end.2021.0251. [DOI] [PubMed] [Google Scholar]
- 19.Aldoukhi A.H., Roberts W.W., Hall T.L., Ghani K.R. Watch your distance: the role of laser fiber working distance on fragmentation when altering pulse width or modulation. J Endourol. 2018;33:120–126. doi: 10.1089/end.2018.0572. [DOI] [PubMed] [Google Scholar]
- 20.Winship B., Wollin D., Carlos E., Li J., Peters C., Simmons W.N., et al. Dusting efficiency of the Moses holmium laser: an automated in vitro assessment. J Endourol. 2018;32:1131–1135. doi: 10.1089/end.2018.0660. [DOI] [PubMed] [Google Scholar]
- 21.Wollin D.A., Carlos E.C., Tom W.R., Simmons W.N., Preminger G.M., Lipkin M.E. Effect of laser settings and irrigation rates on ureteral temperature during holmium laser lithotripsy, an in vitro model. J Endourol. 2017;32:59–63. doi: 10.1089/end.2017.0658. [DOI] [PubMed] [Google Scholar]
- 22.Dionise Z., Tabib C., Tran S., Soto-Palou F., Zhong P., Preminger G., et al. MP05-20 the heat is on: Moses 2.0 popcorning in a novel benchtop 3D kidney model reaches thermal damage thresholds rapidly. J Urol. 2022;207:e76. doi: 10.1097/JU.0000000000002522.20. [DOI] [Google Scholar]
- 23.Brar H., Werneburg G., Sivalingam S. PD37-04 Moses 2.0 or masterpulse? an in vitro comparison of two novel laser systems for dusting and fragmenting in a benchtop model. J Urol. 2022;207:e639. doi: 10.1097/JU.0000000000002595.04. [DOI] [Google Scholar]
- 24.Majdalany S.E., Levin B.A., Ghani K.R. The efficiency of Moses technology holmium laser for treating renal stones during flexible ureteroscopy: relationship between stone volume, time, and energy. J Endourol. 2021;35:S14–S21. doi: 10.1089/end.2021.0592. [DOI] [PubMed] [Google Scholar]
- 25.Nazif O.A., Teichman J.M.H., Glickman R.D., Welch A.J., Khusid J.A., Khargi R., et al. Review of laser fibers: a practical guide for urologists. J Endourol. 2004;18:818–829. doi: 10.1089/end.2004.18.818. [DOI] [PubMed] [Google Scholar]
- 26.Winship B., Terry R., Boydston K., Carlos E., Wollin D., Peters C., et al. Holmium:yttrium-aluminum-garnet laser pulse type affects irrigation temperatures in a Benchtop ureteral model. J Endourol. 2019;33:896–901. doi: 10.1089/end.2019.0496. [DOI] [PubMed] [Google Scholar]
- 27.Khusid J.A., Khargi R., Seiden B., Sadiq A.S., Atallah W.M., Gupta M. Thulium fiber laser utilization in urological surgery: a narrative review. Investig Clin Urol. 2021;62:136. doi: 10.4111/icu.20200467. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 28.Kronenberg P., Hameed B.Z., Somani B. Outcomes of thulium fibre laser for treatment of urinary tract stones: results of a systematic review. Curr Opin Urol. 2021;31:80–86. doi: 10.1097/MOU.0000000000000853. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 29.Scott N.J., Cilip C.M., Fried N.M. Thulium fiber laser ablation of urinary stones through small-core optical fibers. IEEE J Sel Top Quant Electron. 2009;15:435–440. [Google Scholar]
- 30.Keller E.X., De Coninck V., Doizi S., Daudon M., Traxer O. Thulium fiber laser: ready to dust all urinary stone composition types? World J Urol. 2020;39:1693–1698. doi: 10.1007/s00345-020-03217-9. [DOI] [PubMed] [Google Scholar]
- 31.Taratkin M., Laukhtina E., Singla N., Tarasov A., Alekseeva T., Enikeev M., et al. How lasers ablate stones: in vitro study of laser lithotripsy (Ho:YAG and TM-fiber lasers) in different environments. J Endourol. 2019;35:931–936. doi: 10.1089/end.2019.0441. [DOI] [PubMed] [Google Scholar]
- 32.Fried N.M., Irby P.B. Advances in laser technology and fibre-optic delivery systems in lithotripsy. Nat Rev Urol. 2018;15:563–573. doi: 10.1038/s41585-018-0035-8. [DOI] [PubMed] [Google Scholar]
- 33.Wilson C.R., Hardy L.A., Kennedy J.D., Irby P.B., Fried N.M. Miniature ball-tip optical fibers for use in thulium fiber laser ablation of kidney stones. J Biomed Opt. 2016;21 doi: 10.1117/1.JBO.21.1.018003. [DOI] [PubMed] [Google Scholar]
- 34.Panthier F., Doizi S., Lapouge P., Chaussain C., Kogane N., Berthe L., et al. Comparison of the ablation rates, fissures and fragments produced with 150 μm and 272 μm laser fibers with superpulsed thulium fiber laser: an in vitro study. World J Urol. 2020;39:1683–1691. doi: 10.1007/s00345-020-03186-z. [DOI] [PubMed] [Google Scholar]
- 35.Hutchens T.C., Gonzalez D.A., Irby P.B., Fried N.M. Fiber optic muzzle brake tip for reducing fiber burnback and stone retropulsion during thulium fiber laser lithotripsy. J Biomed Opt. 2017;22 doi: 10.1117/1.JBO.22.1.018001. [DOI] [PubMed] [Google Scholar]
- 36.Hall L.A., Gonzalez D.A., Fried N.M. Thulium fiber laser ablation of kidney stones using an automated, vibrating fiber. J Biomed Opt. 2019;24 doi: 10.1117/1.JBO.24.3.038001. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 37.Blackmon R.L., Irby P.B., Fried N.M. Holmium:YAG (λ=2120 nm) versus thulium fiber (λ=1908 nm) laser lithotripsy. Lasers Surg Med. 2010;42:232–236. doi: 10.1002/lsm.20893. [DOI] [PubMed] [Google Scholar]
- 38.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;126:159–167. doi: 10.1111/bju.15079. [DOI] [PubMed] [Google Scholar]
- 39.Blackmon R.L., Irby P.B., Fried N.M. Comparison of holmium:YAG and thulium fiber laser lithotripsy: ablation thresholds, ablation rates, and retropulsion effects. J Biomed Opt. 2011;16 doi: 10.1117/1.3564884. [DOI] [PubMed] [Google Scholar]
- 40.Blackmon R.L., Hutchens T.C., Hardy L.A., Wilson C.R., Irby P.B., Fried N.M. Thulium fiber laser ablation of kidney stones using a 50-μm-core silica optical fiber. Opt Eng. 2014;54 doi: 10.1117/1.OE.54.1.011004. [DOI] [Google Scholar]
- 41.Jansen E.D., Asshauer T., Frenz M., Motamedi M., Delacretaz G., Welch A.J. Effect of pulse duration on bubble formation and laser-induced pressure waves during holmium laser ablation. Lasers Surg Med. 1996;18:278–293. doi: 10.1002/(SICI)1096-9101(1996)18:3<278::AID-LSM10>3.0.CO;2-2. [DOI] [PubMed] [Google Scholar]
- 42.White M.D., Moran M.E., Calvano C.J., Borhan-Manesh A., Mehlhaff B.A. Evaluation of retropulsion caused by holmium:YAG laser with various power settings and fibers. J Endourol. 2009;12:183–186. doi: 10.1089/end.1998.12.183. [DOI] [PubMed] [Google Scholar]
- 43.Hardy L.A., Kennedy J.D., Wilson C.R., Irby P.B., Fried N.M. Analysis of thulium fiber laser induced bubble dynamics for ablation of kidney stones. J Biophot. 2016;10:1240–1249. doi: 10.1002/jbio.201600010. [DOI] [PubMed] [Google Scholar]
- 44.Andreeva V., Vinarov A., Yaroslavsky I., Kovalenko A., Vybornov A., Rapoport L., et al. Preclinical comparison of superpulse thulium fiber laser and a holmium:YAG laser for lithotripsy. World J Urol. 2019;38:497–503. doi: 10.1007/s00345-019-02785-9. [DOI] [PubMed] [Google Scholar]
- 45.Ulvik Ø., Æsøy M.S., Juliebø-Jones P., Gjengstø P., Beisland C. Thulium fibre laser versus holmium:YAG for ureteroscopic lithotripsy: outcomes from a prospective randomised clinical trial. Eur Urol. 2022;82:73–79. doi: 10.1016/j.eururo.2022.02.027. [DOI] [PubMed] [Google Scholar]
- 46.Corrales M., Traxer O. Initial clinical experience with the new thulium fiber laser: first 50 cases. World J Urol. 2021;39:3945–3950. doi: 10.1007/s00345-021-03616-6. [DOI] [PubMed] [Google Scholar]
- 47.Haas C.R., Knoedler M.A., Li S., Gralnek D.R., Best S.L., Penniston K.L., et al. Pulse-modulated holmium:YAG laser vs. the thulium fiber laser for renal and ureteral stones: a single-center prospective randomized clinical trial. J Urol. 2023;209:374–383. doi: 10.1097/JU.0000000000003050. [DOI] [PubMed] [Google Scholar]
- 48.Enikeev D., Okhunov Z., Rapoport L., Taratkin M., Enikeev M., Snurnitsyna O., et al. Novel thulium fiber laser for enucleation of prostate: a retrospective comparison with open simple prostatectomy. J Endourol. 2019;33:16–21. doi: 10.1089/end.2018.0791. [DOI] [PubMed] [Google Scholar]
- 49.Jones P., Hawary A., Beck R., Somani B.K. Role of mini-percutaneous nephrolithotomy in the management of pediatric stone disease: a systematic review of literature. J Endourol. 2021;35:728–735. doi: 10.1089/end.2020.0743. [DOI] [PubMed] [Google Scholar]
- 50.Bhanot R., Jones P., Somani B. Minimally invasive surgery for the treatment of ureteric stones—state-of-the-art review. Res Rep Urol. 2021;13:227–236. doi: 10.2147/RRU.S311010. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 51.Enikeev D., Traxer O., Taratkin M., Okhunov Z., Shariat S. A review of thulium-fiber laser in stone lithotripsy and soft tissue surgery. Curr Opin Urol. 2020;30:853–860. doi: 10.1097/MOU.0000000000000815. [DOI] [PubMed] [Google Scholar]
- 52.Shrestha A., Corrales M., Adhikari B., Chapagain A., Traxer O. Comparison of low power and high power holmium YAG laser settings in flexible ureteroscopy. World J Urol. 2022;40:1839–1844. doi: 10.1007/s00345-022-04040-0. [DOI] [PubMed] [Google Scholar]
- 53.Martov A.G., Ergakov D.V., Guseynov M., Andronov A.S., Plekhanova O.A. Clinical comparison of super pulse thulium fiber laser and high-power holmium laser for ureteral stone management. J Endourol. 2021;35:795–800. doi: 10.1089/end.2020.0581. [DOI] [PubMed] [Google Scholar]
- 54.Karakoyunlu N., Çakıcı M.Ç., Sarı S., Hepşen E., Bikirov M., Kısa E., et al. Efficacy of various laser devices on lithotripsy in retrograde intrarenal surgery used to treat 1–2 cm kidney stones: a prospective randomized study. Int J Clin Pract. 2021;75 doi: 10.1111/ijcp.14216. [DOI] [PubMed] [Google Scholar]
- 55.Abdelbary A.M., Al-Dessoukey A.A., Moussa A.S., Elmarakbi A.A., Ragheb A.M., Sayed O., et al. Value of early second session shock wave lithotripsy in treatment of upper ureteric stones compared to laser ureteroscopy. World J Urol. 2021;39:3089–3093. doi: 10.1007/s00345-020-03560-x. [DOI] [PubMed] [Google Scholar]
- 56.Alghamdi A., Kretschmer A., Stief C.G., Strittmatter F. Influence of the laser pulse shape in the treatment of stones in the upper urinary tract. Investig Clin Urol. 2020;61:594. doi: 10.4111/icu.20200130. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 57.Lu P., Chen K., Wang Z., Song R., Zhang J., Liu B., et al. Clinical efficacy and safety of flexible ureteroscopic lithotripsy using 365 μm holmium laser for nephrolithiasis: a prospective, randomized, controlled trial. World J Urol. 2020;38:481–487. doi: 10.1007/s00345-019-02776-w. [DOI] [PubMed] [Google Scholar]
- 58.Ibrahim A., Elhilali M.M., Fahmy N., Carrier S., Andonian S. Double-blinded prospective randomized clinical trial comparing regular and Moses modes of holmium laser lithotripsy. J Endourol. 2020;34:624–628. doi: 10.1089/end.2019.0695. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 59.Jiang K., Chen H., Yu X., Chen Z., Ye Z., Yuan H. The “all-seeing needle” micro-PCNL versus flexible ureterorenoscopy for lower calyceal stones of ≤2 cm. Urolithiasis. 2019;47:201–206. doi: 10.1007/s00240-018-1049-7. [DOI] [PubMed] [Google Scholar]
- 60.Jin L., Yang B., Zhou Z., Li N. Comparative efficacy on flexible ureteroscopy lithotripsy and miniaturized percutaneous nephrolithotomy for the treatment of medium-sized lower-pole renal calculi. J Endourol. 2019;33:914–919. doi: 10.1089/end.2019.0504. [DOI] [PubMed] [Google Scholar]
- 61.EL-Nahas A.R., Elshal A.M., EL-Tabey N.A., EL-Assmy A.M., Shokeir A.A. Percutaneous nephrolithotomy for staghorn stones: a randomised trial comparing high-power holmium laser versus ultrasonic lithotripsy. BJU Int. 2016;118:307–312. doi: 10.1111/bju.13418. [DOI] [PubMed] [Google Scholar]
- 62.Li L., Pan Y., Weng Z., Bao W., Yu Z., Wang F. A Prospective randomized trial comparing pneumatic lithotripsy and holmium laser for management of middle and distal ureteral calculi. J Endourol. 2015;29:883–887. doi: 10.1089/end.2014.0856. [DOI] [PubMed] [Google Scholar]
- 63.Kumar A., Vasudeva P., Nanda B., Kumar N., Jha S.K., Singh H. A prospective randomized comparison between laparoscopic ureterolithotomy and semirigid ureteroscopy for upper ureteral stones >2 cm: a single-center experience. J Endourol. 2015;29:1248–1252. doi: 10.1089/end.2013.0791. [DOI] [PubMed] [Google Scholar]
- 64.Cimino S., Favilla V., Russo G.I., Saita A., Sortino G., Castelli T., et al. Pneumatic lithotripsy versus holmium:YAG laser lithotripsy for the treatment of single ureteral stones: a prospective, single-blinded study. Urol Int. 2014;92:468–472. doi: 10.1159/000355828. [DOI] [PubMed] [Google Scholar]
- 65.Ganesamoni R., Sabnis R.B., Mishra S., Parekh N., Ganpule A., Vyas J.B., et al. Prospective randomized controlled trial comparing laser lithotripsy with pneumatic lithotripsy in miniperc for renal calculi. J Endourol. 2013;27:1444–1449. doi: 10.1089/end.2013.0177. [DOI] [PubMed] [Google Scholar]
- 66.Razzaghi M.R., Razi A., Mazloomfard M.M., Golmohammadi Taklimi A., Valipour R., Razzaghi Z. Safety and efficacy of pneumatic lithotripters versus holmium laser in management of ureteral calculi: a randomized clinical trial. Urol J. 2013;10:762–766. [PubMed] [Google Scholar]
- 67.Kassem A., ElFayoumy H., ElSaied W., ElGammal M., Bedair A. Laser and pneumatic lithotripsy in the endoscopic management of large ureteric stones: a comparative study. Urol Int. 2012;88:311–315. doi: 10.1159/000336254. [DOI] [PubMed] [Google Scholar]
- 68.Zhang J., Shi Q., Wang G., Wang F., Jiang N. Cost-effectiveness analysis of ureteroscopic laser lithotripsy and shock wave lithotripsy in the management of ureteral calculi in Eastern China. Urol Int. 2011;86:470–475. doi: 10.1159/000324479. [DOI] [PubMed] [Google Scholar]
- 69.Binbay M., Tepeler A., Singh A., Akman T., Tekinaslan E., Sarilar O., et al. Evaluation of pneumatic versus holmium:YAG laser lithotripsy for impacted ureteral stones. Int Urol Nephrol. 2011;43:989–995. doi: 10.1007/s11255-011-9951-8. [DOI] [PubMed] [Google Scholar]
- 70.Garg S., Mandal A.K., Singh S.K., Naveen A., Ravimohan M., Aggarwal M., et al. Ureteroscopic laser lithotripsy versus ballistic lithotripsy for treatment of ureteric stones: a prospective comparative study. Urol Int. 2009;82:341–345. doi: 10.1159/000209369. [DOI] [PubMed] [Google Scholar]
- 71.Arrabal-Polo M.A., Arrabal-Martín M., Miján-Ortiz J.L., Valle-Díaz F., López-León V., Merino-Salas S., et al. Treatment of ureteric lithiasis with retrograde ureteroscopy and holmium:YAG laser lithotripsy vs. extracorporeal lithotripsy. BJU Int. 2009;104:1144–1147. doi: 10.1111/j.1464-410X.2009.08500.x. [DOI] [PubMed] [Google Scholar]
- 72.Patil A., Reddy N., Shah D., Singh A., Ganpule A., Sabnis R., et al. High-power holmium with Moses technology or thulium fiber laser in miniPerc with suction: a new curiosity. J Endourol. 2022;36:1348–1354. doi: 10.1089/end.2021.0915. [DOI] [PubMed] [Google Scholar]
- 73.Pietropaolo A., Hughes T., Mani M., Somani B. Outcomes of ureteroscopy and laser stone fragmentation (URSL) for kidney stone disease (KSD): comparative cohort study using Moses technology 60 W laser system versus regular holmium 20 W laser. JCM. 2021;10:2742. doi: 10.3390/jcm10132742. [DOI] [PMC free article] [PubMed] [Google Scholar]