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Introduction: There are two main mechanisms of stone ablation with long-pulsed infrared lasers: photothermal and photomechanical. Which of them is primary in stone destruction is still a matter of ...

Ureteral stent encrustation is sometimes encountered, especially in cases in which a ureteral stent has been forgotten. An 84-year-old female patient with malignant myeloma underwent metallic ureteral stent insertion to treat malignant ureteral obstruction. At the time of scheduled ureteral stent exchange, the stent was heavily encrusted and could not be removed on either side. We performed endoscopic lithotripsy to remove the encrusted ureteral stents. The bilaterally encrusted metallic ureteral stents were successfully removed using Ho:YAG laser lithotripsy after inserting another ureteral stent placement besides the encrusted metallic ureteral stents.

Both retrograde and antegrade approach contributed to the success of a delicate endoscopic procedure. Even when guidewire did not pass thorough to the stenosis lesion, lightning and contrast reagents contributed the way through to the stenosis lesion., Both retrograde and antegrade approach contributed to the success of a delicate endoscopic procedure. Even when guidewire did not pass thorough to the stenosis lesion, lightning and contrast reagents contributed the way through to the stenosis lesion

To evaluate calyceal irrigation fluid temperature changes during flexible ureteroscopic Ho:YAG laser lithotripsy. Between May 2019 and January 2020, patients with kidney stones undergoing flexible ureteroscopic Ho:YAG laser lithotripsy were enrolled. A K-type thermocouple was applied for intraoperative temperature measurement. Laser was activated at different power (1 J/20 Hz and 0.5 J/20 Hz) and irrigation (0 ml/min, 15 ml/min and 30 ml/min) settings, temperature–time curve was drawn and time needed to reach 43 °C without irrigation was documented. Thirty-two patients were enrolled in our study. The temperature–time curve revealed a quick temperature increase followed by a plateau. With 15 ml/min or 30 ml/min irrigation, 43 °C was not reached after 60 s laser activation at both 1 J/20 Hz and 0.5 J/20 Hz. At the power setting of 1 J/20 Hz and irrigation flow rate of 15 ml/min, the temperature rise was significantly higher than other groups. Without irrigation, the time needed to reach 43 °C at 1 J/20 Hz was significantly shorter than that at 0.5 J/20 Hz (8.84 ± 1.41 s vs. 13.71 ± 1.53 s). Ho:YAG laser lithotripsy can induce significant temperature rise in calyceal fluid. With sufficient irrigation, temperatures can be limited so that a toxic thermal dose is not reached, when irrigation is closed, the temperature increased sharply and reached 43 °C in a few seconds.

Aim: To test the characteristics of a hybrid laser (combination of a thulium and blue diode laser) vs thulium and Ho:YAG lasers regarding soft tissue ablation. Methods: Tissue samples of fresh nonf...

We demonstrate a direct diode-pumped passively Q-switched (PQS) Tm/Ho composite laser with a developed compact hybrid cavity, where the lasing wavelengths were changeable from Ho laser to Tm laser via decreasing initial transmittance of the crystalline Cr:ZnSe saturable absorbers (SAs) from 95%, 92%, to 89%. Using a common 808 nm diode laser as the pump source, maximum average output power of 390 mW, maximum pulse energy of 39 uJ, and the shortest pulse with a full width at half maximum of 22 ns were obtained at lasing wavelengths of 2122 nm, 2090 nm, and 2011 nm respectively, where these peak wavelengths remained stable during the PQS processes with different SAs.

Verruca Vulgaris or wart is a common skin disease caused by human papillomavirus (HPV) infection. Warts are usually located on fingers, hands, elbows and feet. Anogenital region is an uncommon location for warts. Three children with large perianal warts were treated by holmium: Yttrium Aliminum Garnet (Ho-YAG) laser. No recurrences or significant complications were seen in 2 years of follow up period. Ho-YAG Laser was successfully applied in the treatment of pediatric perianal warts. It is a safe and effective method.

The aim of this study was to summarize the recent innovations of the holmium laser with special respect to lithotripsy. Therefore, we reviewed and discussed the most recent and pivotal publications on this topic.The current literature underlines Holmium:yttrium-aluminium-garnet (Ho:YAG) lithotripsy as a well tolerated and efficient method to treat urinary calculi. Because of modifiable adjustments of pulse energy, pulse frequency, and pulse length, especially with newer generations of holmium lasers, urologists can accurately choose between the 'fragmentation' and 'dusting' technique with its alterations. Recently, the 'Moses mode' as a new feature incorporated in the Lumenis Pulse P120H holmium laser showed less retropulsion with higher rates of stone ablation because of an improved energy transmission from the laser fiber towards the targeted calculus in in-vitro studies.Based on technological developments, Ho:YAG laser lithotripsy has become more efficient in reducing retropulsion and increasing stone ablation volume. However, despite its widespread use as a lithotripter, a newly developed thulium fiber laser, which has already shown promising results in experimental studies, could become an alternative in future practice.

The compact self-mode-locking Ho:YAG laser pumped by the Tm-doped fiber laser was obtained based on the re-absorption effect. At the incident pump power of 26.9 and 35.4 W, the pulse widths of 431.3 and 471.6 ps were achieved, respectively, and the corresponding average powers reached 3.3 and 4.27 W leading to the optical-to-optical efficiencies of 12.26% and 12.06%, respectively. The center wavelength was 2128.36 nm and the repetition rate was 656.6 MHz. To the best of our knowledge, this is the first report on the self-mode-locking Ho:YAG laser applying the re-absorption effect as the modulating mechanisms. The numerical analysis on the photon density and population inversion density considering the re-absorption loss could demonstrate the contribution of the re-absorption effect in the pulse generation. The compact configuration with the high repetition rate and the room-temperature operation could determine the promising future of self-mode-locking Ho:YAG in application areas.

For the aging population, surgery for lumbar spinal canal stenosis (LSCS) requires minimally invasive procedures. Recently, trans-sacral epiduroscopic laser decompression for lumbar disc herniation has been reported with good results. In this study, we devised a new method to perform trans-sacral epiduroscopic laser ablation of the ligamentum flavum (LF), known to be the major cause of LSCS. Using a live pig, this study aims to evaluate the efficacy, safety, and drawbacks of this procedure.Using an epiduroscope, we observed intra-spinal canal structures and then examined the feasibility and problems of a decompression procedure to ablate the LF using holmium:YAG (Ho:YAG) laser. The pig was observed for behavioral changes and neurological deficits after the procedure. Histological analysis was performed to evaluate the amount of tissue ablation and damage to surrounding tissues.Although it was possible to partially ablate the LF using the Ho:YAG laser under epiduroscopy, it was difficult to maintain a clear field of view, and freely decompressing the target lesion has been a challenge. After the first two experiments, the pig neither showed abnormal behavior nor any signs of pain or paresis. However, in the third experiment, the pig died during the operation. On autopsy, no thermal or mechanical injury was noted around the ablated site, including the dura mater and nerve root. Histological analysis showed that the LF and lamina were deeply ablated as the laser power increased, and no damage was noted on surrounding tissues beyond a depth of 500 μm.Although Ho:YAG laser could ablate the ligamentum and bone tissues without causing damage to surrounding tissues, it was difficult to completely decompress the LF under epiduroscopy. This method is a potentially highly invasive procedure that requires caution in its clinical application and needs further improvement in terms of the instruments and techniques used.

Ureteroscopic stone dusting utilizing a high power laser system has become more popular in recent years due to the production of finer debris/remains, lower retropulsion, and shorter operation time (potential to avoid the routine use of post-operative stenting and the use of ureteral access sheaths (UAS)). Typical dusting settings are lower pulse energy (as low as 0.2 J) with higher frequency (up to 80 Hz). This study investigates the best dusting mode to produce a high ablation rate and low retropulsion. The objective of the study was to evaluate the performance of a concept optimal dusting mode. In vitro investigations of Ho:YAG laser-induced stone ablation and retropulsion were performed with a benchtop model in a highly reproducible manner using a hands-free setup and measuring the effects of multiple pulses. A systematic comparison of the performance (ablation and retropulsion) of the concept optimal dusting mode against a reference laser dusting mode was conducted. Within this benchtop test model, the optimal dusting mode had a relatively fast ablation rate while keeping retropulsion low.

The Ho:YAG laser has been the favored lithotripter for treating urinary calculus since shortly after its introduction in the 1990s because it can fragment all calculus compositions and produces less calculus migration (retropulsion) during treatment than the short-pulsed lasers. Although the lamp-pumped Ho:YAG laser has been commercialized for ureteroscopic laser lithotripsy (URS) for almost 25 years, the lamp-pumped laser rod's transient thermal behavior under an out-of-control lamp discharge has not been reported. A safety question arises: how big is the laser output under an out-of-control lamp discharge? The objective of this study is to simulate the transient thermal behavior of the lamp-pumped laser rod. The temperature profile inside the laser rod is transformed into an equivalent thermal lens, and from the time interval of the variation of the thermal lens between the lasing threshold and the maximum value of the stable region, we can estimate the level of the laser output. The simulation tool used for this study is the Ansys Fluent. The transient thermal behavior of the lamp-pumped laser rod under an out-of-control lamp discharge was reported. Optimization of the pumping pulse for the desired laser output pulse is for future study.

Lumbar foraminal stenosis has been identified as a common cause of radicular symptoms and can lead to persistent pain after prolonged treatment. A facet-preserving microdecompression technique using a paraspinal approach has been considered the gold standard for the surgical treatment of lumbar foraminal or far lateral stenosis but has been associated with postoperative leg pain or dysesthesia. More recently, authors have reported the use of a technique known as endoscopic foraminal discectomy with or without foraminotomy for the treatment of foraminal stenosis. Recent advancement in endoscopic devices as well as the use of a side-firing, holmium:yttrium-aluminum-garnet (Ho:YAG) laser has further the surgeon to treat foraminal stenosis more quickly and with less complications.

Lumbar intervertebral disc herniation (LDH) is a clinically symptomatic condition caused by compression of the spinal nerve root by protruded disc material. LDH can be treated with various endoscopic procedures. Recently, trans-sacral epiduroscopic laser decompression (SELD) using epiduroscopy and laser is one of the preferred options for minimally invasive treatment in lumbar disc diseases. Epiduroscopy has been employed because of the smaller diameter of the access portal and the flexible fiber when compared with transforaminal endoscopic lumbar discectomy. It allows treatment of a symptomatic herniated disc that has failed to respond to conservative treatment. SELD showed rapid improvement of back pain and radiculopathy with significant differences in the visual analog scale (VAS) and Oswestry Disability Index (ODI) scores between preoperative and postoperative data in the present study. The advantages of the SELD are direct decompression by laser and targeted mechanical adhesiolysis through direct visualization and very low complication rates. SELD is a safe and effective treatment for lower back and leg pain which arise from a herniated lumbar disc.

Posterior endoscopic cervical foraminotomy (PECF) is one of the minimally invasive procedures that solve the lateral pathology of cervical spine that can cause radiating pain. In the past, it was performed as an operation to enlarge the incision, but due to the recent development of the endoscope, effective treatment with minimal incision has become possible. At the same time, with the development of lasers along with endoscopy, these treatment techniques are creating a better prognosis through more sophisticated and effective methods. It is important to understand in which cases these techniques are performed properly and how to safely and effectively perform these techniques.

Symptomatic thoracic disc herniation (TDH) is rare and surgical intervention is even more uncommon. Several surgical approaches have been developed to address adequate surgical decompression with minimal approach-related morbidity. Transforaminal endoscopic thoracic discectomy (TETD) has brought in a paradigm shift in the management of thoracic disc herniation in its least approach-related complications and wider application for various levels of herniation. Ho:Yag laser is an essential surgical instrument for endoscopic discectomy for safe and effective surgery. In this chapter, authors describe tips and trick of thoracic endoscopic discectomy using laser.

Anterior endoscopic cervical annuloplasty is an effective treatment in alleviating cervical discogenic headache or neck pain caused by the degenerated annulus with contained disc herniation. In particular, Ho:YAG laser is the most important surgical tool for efficient and accurate surgery under the endoscopic visualization. In this chapter, we will describe tips and pearls for the use of endoscopic laser in anterior cervical endoscopic annuloplasty.

Anterior endoscopic cervical discectomy is an effective treatment for soft disc herniation causing cervical radiculopathy and myelopathy. In particular, Ho:YAG laser is the most important surgical tool for efficient and accurate surgery under the endoscopic visualization in a narrow space. In this chapter, we will describe tips and pearls for the use of endoscopic laser in anterior cervical endoscopic discectomy.

Foraminal disc herniations present the unique surgical challenge for exiting nerve root retraction and decompression. Severe radiating pain arises from impingement of existing nerve root ganglion by foraminal disc herniation. In this chapter, we describe rotate-to-retract technique for endoscopic decompression of foraminal disc herniations.

The main advantage of endoscopic surgery is that it minimizes skin incision, preserves bone and muscle tissue as much as possible, and has less bleeding than incision surgery. Laser has been used in various medical fields since it was discovered in 1958. The authors describe the method of discectomy using Ho:YAG laser after transforaminal approach in paramedian disc herniation and intend to review literature.

Purpose: To evaluate the efficacy of new super pulse thulium fiber laser (SP TFL) and compare it with holmium laser for ureterolithotripsy. Patients and Methods: A total of 174 patients with solita...

Background Treatment of broncholithiasis is complex, especially in the case of a large or transbronchial broncholith. Holmium-yttrium aluminum garnet (Ho:YAG) laser lithotripsy may be a useful treatment in broncholithiasis; however, as it is not yet common practice, the optimal parameters are unknown. Methods We performed a single-center retrospective analysis of the clinical data of 13 broncholithiasis patients who underwent Ho:YAG laser lithotripsy from May 2012 to October 2018. Results For the 13 patients (2 males and 11 females), Ho:YAG laser lithotripsy was performed 17 times, in total. All procedures were performed under general anesthesia with rigid bronchoscopy. We initially set the Ho:YAG laser to a pulse frequency of 5 Hz and a pulse energy of 0.8 J, gradually increasing these as required. The pulse frequency range we employed was 5–15 Hz, and the pulse energy range was 0.8–1.6 J. All broncholiths were successfully extracted after lithotripsy, and all symptoms improved. Hemoptysis, bronchial esophageal fistula, and pneumonia were the most common complications; however, there were no long-term complications. Conclusions Ho:YAG laser lithotripsy is an effective and safe treatment for broncholithiasis, over a long-term follow up.

BACKGROUND AND OBJECTIVES To report the first experiences with a newly available Ho:YAG laser system for the treatment of salivary stones. STUDY DESIGN/MATERIALS AND METHODS A retrospective study in a tertiary referral center was conducted. Patients diagnosed with sialolithiasis were treated in Erlangen using the Calculase III™ Ho:YAG laser (Karl Storz, Tuttlingen, Germany). Preset parameters had a frequency of 4 Hz and energy of 0.8-1.2 J, resulting in 3.2-4.8 W. Following total fragmentation, one to two serial sialendoscopies were performed to achieve complete fragment clearance. RESULTS A total of 55 stones in 49 patients were treated; 17 stones in 15 submandibular glands and 38 in 34 parotids. In total, 61 laser lithotripsies (range 1-3 per stone) were performed using various modes (long, short, and burst) and with preset parameters of 4 Hz and energy of 0.8-1.2 J, resulting in effective power of 3.2-4.8 W. Complete fragmentation was achieved in all the accessible stones. Sialendoscopes, fibers, or the mode used had no significant influence on success rates. A multimodal therapy concept was employed to treat stones in 12.24% of the cases; 95.92% of the patients were ultimately stone-free, and all became symptom-free. All glands were preserved. CONCLUSIONS The new Calculase III™ Ho:YAG laser was effective in the treatment of sialolithiasis with no increased risk of complications in the patients or damage to the sialendoscopes. Clinical factors such as the type of gland involved, or the location and size of stones had a greater impact on success rates than the technical or preset parameters. Lasers Surg. Med. © 2020 Wiley Periodicals LLC.

INTRODUCTION AND OBJECTIVE:Holmium: YAG (Ho:YAG) laser is currently the standard for lithotripsy. Recently, Superpulsed Thulium Fiber Laser (TFL) has been evaluated as an alternative for lithotrips...

Introduction: Besides extracorporeal shockwave lithotripsy, semi-rigid ureteroscopy (URS) has become an equal therapy of choice for the treatment of most distal ureteric stones. Before the wide availability of laser lithotripsy as a tool for stone fragmentation, pneumatic lithotripsy was, and still is, widely used. In a country like Iraq, availability and affordability are the huge questions asked. Besides the capital investment for a laser machine, the pneumatic device is reusable, whereas the laser fibers are limited in their reusability. This makes pneumatic lithotripsy a more cost-effective option, at least in our setting. The question remains whether both options, compared in our setting with our limited resources, are equally effective and beneficial to our patients. Patients and Methods: Fifty patients were included in our prospective study who underwent URS for the treatment of a distal ureteric stone. Half each (n = 25) underwent pneumatic (group A) or laser lithotripsy (group B). Inclusion criteria were a single distal ureteric stone measuring 7–20 mm in largest diameter, no anatomical abnormality, age >18 years, and an unsuccessful attempt of medical expulsion therapy. Patients with signs of urinary infection and pregnant women were excluded. All patients were operated upon under spinal anesthesia. Data recorded included operation time, stone size, type of scope and lithotripter, complications, hospital stay, and stone-free rate. Results: Both groups did not show statistically significant differences in patient demography, stone size, operation time, complications, and stone-free rates (p > 0.05). Conclusion: Both pneumatic and Ho:YAG laser lithotripsy are equally effective and safe in treating distal ureteric stones in our setting. If the cost and availability of laser treatment is an issue, pneumatic lithotripsy is a viable and more cost-effective option.

Infrared neural stimulation (INS) has the potential to serve as a spatially precise tool for neuroscientists and clinicians. Because of difficulties comparing various INS techniques in the current literature, we present a study comparing the stimulation threshold and transition rate to 100% activation probability for diode and Ho:YAG lasers. The stimulation threshold was lower for the Ho:YAG than the diode lasers across all examined spot sizes. The Ho:YAG also exhibited a nearly binary transition to 100% activation that can be mimicked with diode lasers by decreasing the pulse width. These results will help maximize the performance of laser diodes for INS.

For delivery of high power Ho:YAG laser, a fiber with 7 tubes and a core of 40µm was designed. Also we designed a coupling structure and a waterproof structure at either end of fiber. © 2020 The Author(s)

Introduction: Holmium:yttrium–aluminium–garnet (Ho:YAG) is currently the gold standard for lithotripsy for the treatment of all known urinary stone types. Stone composition and volume are major determinants of the lithotripsy. This in vitro study evaluated the required energy to ablate 1 mm3 of various stone types with different laser settings using Ho:YAG. Methods: 272 µm core-diameter laser fibers (Boston Scientific©) were connected to a 30 Watt MH1 Ho:YAG generator (Rocamed®). An experimental setup consisting of immerged human stones of calcium oxalate monohydrate (COM), uric acid (UA) or cystine (Cys) was used with a single pulse lasing emission (0.6/0.8/1 J), in contact mode. Stones were dried out before three-dimensional scanning to measure ablation volume per pulse (AVP) and required energy to treat 1 mm3 (RE). Results: All settings considered, ablation volumes per pulse (AVP) for COM were significantly lower than those for UA and Cys (p = 0.002 and p = 0.03, respectively), whereas AVP for Cys was significantly lower than those for UA (p = 0.03). The mean REs at 0.6 J pulse energy (PE) for COM, Cys and UA were 34, 8.5 and 3.2 J, respectively The mean REs at 1 J PE for COM, Cys and UA were 14.7, 6.4 and 2 J, respectively. At 0.6 J PE, RE for COM was more than tenfold and fivefold higher than those for UA and Cys, respectively. Conclusion: This in vitro study shows for the first time a volumetric evaluation of Ho:YAG efficiency by the ablation volume per pulse on human stone samples, according to various pulse energies. The REs for COM, UA and Cys should be considered in clinical practice. In vivo imaging was performed at Life Imag-ing Facility of Paris Descartes University (Plateforme Imageries du Vivant), supported by France Life Imaging (grant ANR-11-INBS-0006) and Infrastructures Biologies-Santé.

AIM The aim of this study was to examine the effects of simultaneous epiduroscopic laser neural disc decompression (ELND) and percutaneous laser disc decompression (PLDD) applications using a holmium:yttrium-aluminum-garnet (Ho:YAG) laser in Michigan State University (MSU) classification 3AB herniated discs on VAS and Oswestry Disability Index (ODI) scores. METHODS In this prospective observational study, ELND and PLDD procedures performed between January 2016 and December 2017 were examined. Preoperative, postoperative week 2, postoperative month 2, and postoperative month 6 ODI and VAS scores were obtained from patient files, and postoperative month 12 ODI and VAS scores were obtained from face-to-face interviews with patients and recorded. RESULTS The data of 41 patients treated with simultaneous ELND and PLDD using a Ho:YAG laser were included in this study. Postoperative VAS scores of the patients were compared with preoperative values, and it was found that postoperative week 2, postoperative month 2, postoperative month 6, and postoperative month 12 VAS and ODI scores were significantly different compared to preoperative scores (P = 0.001; P

For the first time, a CdSiP2-pumped crystal has produced over 25W of mid-IR output demonstrating the viability of this material for high average power applications.

A compact high energy co-doped Tm:Ho:YAG Q-switched laser side-pumped by the 785 nm quasi-continuous wave (QCW) laser diodes (LDs) at room temperature is demonstrated. Up to 130 mJ output energy at 2.1 μ m has been generated, operating at 5 Hz repetition rate with a pulse duration of 73.7 ns. The average beam quality factor of M 2 is measured to be ∼ 3.5. This laser has a simple design and compact structure, which is very suitable for many applications. To the best of our knowledge, this is the highest output energy for LDs pumped single rod Tm:Ho:YAG laser.

Nowadays, various laparoscopic instruments for tissue dissection and vessel coagulation are available. However, there are ongoing studies dedicated to "ideal" type of energy suitable for this aim. Laser radiation has been used for many years in medical practice and it is established as reliable and effective method in surgical armamentarium. The ability to provide highly precision and well-controlled action on the tissues, improved hemostasis, easy adaptability to fiber-optic and minimally invasive delivery systems, as well as the possibility of facilitating complex dissection made lasers an important tool for surgeons. The mechanism and methods of laser energy using in urology have been studied since 1980s, but there is still no consensus on the optimal type of laser and its settings during urological surgeries, which determines the importance of further researches dedicated to this promising form of energy.

A Ho:SSO crystal was employed as an efficient saturable absorber Q switch for the pulsed Ho:YAG laser for the first time. The characteristics of the passive Q-switch Ho:YAG laser were studied with different incident pump power and different laser energy density around the Ho:SSO. The single pulsed energy varied from 8.3 μJ to 76.6 μJ with the increasing of the incident power from 2.2 W to 8.2 W. The maximum repetition rate was 42.1 kHz, and the minimum pulsed duration was 48 ns. The maximum single-pulse peak power was 1.53 kW. The output center wavelength shifted from 2090.1 nm (the continuous-wave mode) to 2091.3 nm (the passive Q-switch mode).

We report an acoustic Q-switched Ho:YAG laser end-pumped by a 1,908 nm Tm:YLF laser. The doping concentration of Ho:YAG crystal is 2 at.%, and dimensions o5×20 mm. We measure the pulsedlaser output characteristics of the Ho:YAG laser at different repetition rates (RF). Under optimum experimental conditions, the high-power 2.1 μm output power reaches 4.17 W at a given pump power of 13.25 W and repetition frequency of 8.0 kHz. For a slope efficiency of 16.88%, the corresponding optical-to-optical conversion efficiency reaches 31.47%. We obtain a minimum single pulsed energy of 7.36 mJ and a pulse width of 52.8 ns at a pump power of 10.52 W and repetition rate of 0.5 kHz, with a peak power of 139 kW.

Holmium doped radially polarised lasers operating in the 2.1 μm spectral region are of great interest as they provide benefits of operation in the atmospheric transmission window (2.1–2.25 μm), absorption in transparent polymers, as well as the materials processing benefits that are beginning to be realised from utilising select higher order modes [1]. We report on the development of a 50W CW radially polarised Ho:YAG laser operating at 2090nm.

This chapter provides an in-depth summary of the application of the holmium:YAG laser in ureteroscopy. First, the basic physics of laser lithotripsy is reviewed. Laser generators and the peculiarities of laser fibers are then discussed, with a special focus on their application in flexible ureteroscopy. Finally, some of the studies evaluating the outcomes and safety profile of holmium laser lithotripsy are reviewed.

The aim of this study was to compare the thermal effects of Ho:YAG and Tm-fiber lasers during lithotripsy in an in-vitro model via real-time temperature measurement. We compared a Ho:YAG laser (pav up to 100 W, Lumenis, Yokneam, Israel) and a superpulse Tm-fiber laser (SP TFL, pav up to 40 W, NTO IRE-Polus, Fryazino, Russia), both equipped with 200 µm bare-ended fibers. The following settings were used: 0.2 J, 40 Hz (nominal pav 8 W). Power meter FieldMaxII-TO (Coherent, Santa Clara, CA, USA) was used to verify output laser power (pav). Each laser was fired for 60 s in two setups: (1) thermos-insulated (quasi-adiabatic) cuvette; (2) actively irrigated setup with precise flow control (irrigation rates 0, 10, 35 mL/min). Power measurements performed before the test revealed a 10% power drop in Ho:YAG (up to 7.2 ± 0.1 W) and 6.25% power drop in SP TFL (up to 7.5 ± 0.1). At the second step of our experiment, irrigation reduced the respective temperatures in the same manner for both lasers (e.g., at 35 mL/s SP TFL − 1.9 °C; for Ho:YAG laser − 2.8 °C at 60 s). SP TFL and Ho:YAG lasers are not different in terms of volume-averaged temperature increase when the same settings are used in both lasers. Local temperature rises may fluctuate to some degree and differ for the two lasers due to varying jet streaming caused by non-uniform heating of the aqueous medium by laser light.

Background: There are limited number of studies comparing the results of Holmium:YAG laser lithotripsy (LL) and pneumatic lithotripsy (PL) for pediatric ureteral stones. Objectives: To perform a comparative analysis of LL and PL in the management of ureteral stones in children and adults. Study design: Ninety-eight children (56 boys and 42 girls) and 623 adults (360 men and 263 women), who were treated for ureteral stones at our clinic between 2017 and 2019, were the subjects of this study. Patients were grouped according to their age as group 1 (n:98, pediatric [

INTRODUCTION AND OBJECTIVES:Ho:YAG laser is the “gold standard” in the treatment of lower and upper urinary tract stones. Ho:YAG laser with Moses Technology is new technology to reduce retropulsion...