Long-term functional outcomes and surgical retreatment after thulium laser enucleation of the prostate: A 10-year follow-up study

BACKGROUND

To evaluate the 10-year functional outcomes (primary) and frequency and predictors of BPH surgical retreatment (secondary) after ThuLEP.

MATERIALS AND METHODS

A single-center retrospective analysis of consecutive patients undergoing ThuLEP between 2010 and 2013 was performed. Inclusion criteria were: age ≥ 40 years, prostate volume (PV) ≥ 80 mL, International Prostate Symptom Score (IPSS)-Total score ≥ 8 points. IPSS-Total score was the primary outcome, and BPH surgical retreatment rate was the secondary outcome. Paired t-test, McNemar test, and Wilcoxon signed-rank test were used to compare variables. Logistic regression analysis was performed to evaluate predictors of surgical retreatment.

RESULTS

A total of 410 patients with a mean ±SD age of 63.9 ± 9.7 years and a PV of 115.6 ± 28.6 mL were included. Mean ±SD follow-up was 108.2 ± 29.6 months. IPSS-Total score was significantly improved at 1 year compared to baseline (23.3 ± 4.7 vs. 10.3 ± 3.8; p<0.001). It was similar after 5 years (10.5 ± 3.6 vs. 10.7 ± 5.0; p=0.161), with a significant worsening at 10 years (10.3 ±4.8 vs. 13.8 ±4.5; p=0.042) but remaining statistically and clinically better than baseline (13.8 ±4.5 vs. 22.1 ±4.3; p<0.001). After 10 years, 21 (5.9%) patients had undergone BPH reoperation. Baseline PV (adjusted OR 1.27, 95% CI 1.09-1.41; p<0.001) and time from BPH surgery (adjusted OR 1.32, 95% CI 1.15-1.43; p<0.001) were predictors of BPH surgical retreatment.

CONCLUSIONS

ThuLEP is associated with optimal functional outcomes and a low frequency of BPH surgical retreatment in the long-term. Baseline PV and time from surgery were predictors of BPH reoperation.

Evaluation of the learning curve for Thulium laser enucleation of the prostate in a contemporary cohort

PURPOSE

To assess the learning curve of Thulium laser enucleation of the prostate (ThuLEP) of a single surgeon.

METHODS

Hundred patients suffering from benign prostatic hyperplasia were treated by the same surgeon. In all cases, a well-trained urologist was present in the operating room. Patients urinary function was assessed preoperatively using the International Prostate Symptoms Score (IPSS), maximum flow rate and Post-Void Residual volume. Preoperative prostate volume was recorded. Enucleation and morcellation efficiency and complication rate were evaluated. Patients were divided into 5 cohorts of 20 consecutive cases to assess changes in outcomes through time.

RESULTS

Mean age of patients was 73.1 years (SD 17.5) and mean prostate volume was 89.7 ml (SD 55.1). Overall, mean enucleation and morcellation efficiency were 1.7 (SD 2.9) and 5.1 (SD 2.7) g/min. A statistically significant increase in enucleation efficiency was observed when comparing cohort 1 vs 2 (0.9 vs 1.3 g/min, p = 0.03) and cohort 2 vs 3 (1.3 vs 1.7 g/min, p = 0.02). A statistically significant increase in morcellation efficiency was observed when comparing cohort 1 vs 2 (2.8 vs 3.7 g/min, p = 0.02) and cohort 2 vs 3 (3.7 vs 4.9 g/min, p = 0.03). In both cases, no significant differences were observed when comparing the following cohorts. Complication rate showed no significant differences throughout the caseload.

CONCLUSIONS

In our single-surgeon experience, we observed a learning curve of nearly 60 cases for the ThuLEP procedure in presence of a well-trained surgeon. Complication rate was low from the beginning of surgical experience.

Analyzing global research trends and focal points in the utilization of laser techniques for the treatment of urolithiasis from 1978 to 2022: visualization and bibliometric analysis

Laser lithotripsy is gaining global prominence and is a dynamically progressing field marked by a continual influx of new and comprehensive research each year. Recently, there has been a noticeable shift toward the adoption of various kinds of lasers, such as holmium: yttrium-aluminum-garnet (Ho:YAG) and thulium fiber (TFL) lasers. Consequently, we aim to conduct a bibliometric analysis to analyze key areas of research activity within scientific publications that center on the utilization of laser techniques in urolithiasis. A search of the literature spanning from 1978 to 2022 was carried out on 25 December 2023 using the Scopus database to explore research related to the application of laser techniques for urolithiasis treatment. Visualization analysis was performed using VOSviewer software (version 1.6.20). We examined 962 publications that met the specified criteria, 791 (82.22%) of which were original articles. The analysis of the retrieved publications indicated a consistent increase in research output from 1978 to 2022; a particularly noteworthy surge occurred after 2003. In particular, the U.S. claimed the leading position as the most productive country, contributing 211 articles (21.93%). However, India had the highest research productivity according to the adjustment index of 19.08. In the European region, 324 publications (33.68% of the total) originated from 25 countries. The Journal of Endourology contributed the most between 1978 and 2022 (n = 96, 9.98%). The most cited paper examined the effectiveness of holmium: yttrium-aluminum-garnet (Ho:YAG) lasers, while a subsequent study focused on the use of a thulium fiber laser (TFL), an emerging laser technology that has gained increased recognition. Co-occurrence analysis revealed three distinct clusters focusing on the types of laser technology, minimally invasive approaches, and success rate/postoperative complications. This comprehensive investigation delves into the global landscape of laser use for the treatment of urolithiasis. This review supports the emerging clinical concept of using various types of laser technology for urolithiasis treatment. Moreover, the hot issues that researchers should focus on based on the findings of this study are the use of different types of laser lithotripsy in view of the surgical approach, success rate and complications.

Is "Kidney Stone Calculator" efficient in predicting ureteroscopic lithotripsy duration? A holmium:YAG and thulium fiber lasers comparative analysis

PURPOSE

This study aimed to evaluate the ability of Kidney Stone Calculator (KSC), a flexible ureteroscopy surgical planning software, to predict the lithotripsy duration with both holmium:YAG (Ho:YAG) and thulium fiber laser (TFL).

METHODS

A multicenter prospective study was conducted from January 2020 to April 2023. Patients with kidney or ureteral stones confirmed at non-contrast computed tomography and treated by flexible ureteroscopy with laser lithotripsy were enrolled. "Kidney Stone Calculator" provided stone volume and subsequent lithotripsy duration estimation using three-dimensional segmentation of the stone on computed tomography and the graphical user interface for laser settings. The primary endpoint was the quantitative and qualitative comparison between estimated and effective lithotripsy durations. Secondary endpoints included subgroup analysis (Ho:YAG-TFL) of differences between estimated and effective lithotripsy durations and intraoperative outcomes. Multivariate analysis assessed the association between pre- and intraoperative variables and these differences according to laser source.

RESULTS

89 patients were included in this study, 43 and 46 in Ho:YAG and TFL groups, respectively. No significant difference was found between estimated and effective lithotripsy durations (27.37 vs 28.36 min, p = 0.43) with a significant correlation (r =  + 0.89, p < 0.001). Among groups, this difference did not differ (p = 0.68 and 0.07, respectively), with a higher correlation between estimated and effective lithotripsy durations for TFL compared to Ho:YAG (r =  + 0.95, p < 0.001 vs r =  + 0.81, p < 0.001, respectively). At multivariate analysis, the difference was correlated with preoperative (volume > 2000 mm3 (Ho:YAG), 500-750 mm3 SV and calyceal diverticulum (TFL)), operative (fragmentation setting (p > 0.001), and basket utilization (p = 0.05) (Ho:YAG)) variables.

CONCLUSION

KSC is a reliable tool for predicting the lithotripsy duration estimation during flexible ureteroscopy for both Ho:YAG and TFL. However, some variables not including laser source may lead to underestimating this estimation.

Laser Technology Advancements in the Treatment of Benign Prostatic Hypertrophy

PURPOSE OF REVIEW

Lasers have had a significant impact on the treatment of benign prostatic hypertrophy. This article attempts to distill the advancements in laser technology for the treatment of benign prostatic hypertrophy (BPH) into key and understandable points to help make this topic more accessible to urologists.

RECENT FINDINGS

The holmium:yttrium-aluminum-garnet (YAG) laser, one of the most significant lasers in the field of urology, has recently been improved with pulse modulating technology (Moses™ technology). New thulium:YAG technology allows both pulsed and continuous wave modes. The thulium fiber laser is one of the newer lasers to come to market and has been shown to have effective and safe outcomes. GreenLight™ lasers are predominantly used in photovaporization procedures and have also been studied extensively, although less in recent years. The modern urologist is fortunate to have many high-quality lasers and a wide variety of surgical techniques to choose from when treating BPH. Understanding the basic laser principles and applications will help urologists to select the best treatment options for their patients with BPH.

thulium laser in an anatomic hydrogel kidney model

As laser technology has advanced, high-power lasers have become increasingly common. The Holmium: yttrium-aluminum-garnet (Ho:YAG) laser has long been accepted as the standard for laser lithotripsy. The thulium fiber laser (TFL) has recently been established as a viable option. The aim of this study is to evaluate thermal dose and temperature for the Ho:YAG laser to the TFL at four different laser settings while varying energy, frequency, operator duty cycle (ODC). Utilizing high-fidelity, 3D-printed hydrogel models of a pelvicalyceal collecting system (PCS) with a synthetic BegoStone implanted in the renal pelvis, laser lithotripsy was performed with the Ho:YAG laser or TFL. At a standard power (40W) and irrigation (17.9 ml/min), we evaluated four different laser settings with ODC variations with different time-on intervals. Temperature was measured at two separate locations. In general, the TFL yielded greater cumulative thermal doses than the Ho:YAG laser. Thermal dose and temperature were typically greater at the stone when compared away from the stone. Regarding the TFL, there was no general trend if fragmentation or dusting settings yielded greater thermal doses or temperatures. The TFL generated greater temperatures and thermal doses in general than the Ho:YAG laser with Moses technology. Temperatures and thermal doses were greater closer to the laser fiber tip. It is inconclusive as to whether fragmentation or dusting settings elicit greater thermal loads for the TFL. Energy, frequency, ODC, and laser-on time significantly impact thermal loads during ureteroscopic laser lithotripsy, independent of power.

Comparison of Thulium Fiber Laser versus Holmium laser in ureteroscopic lithotripsy: a Meta-analysis and systematic review

OBJECTIVES

To compare the efficacy and safety of thulium fiber laser (TFL) to holmium: YAG (Ho: YAG) laser in ureteroscopic lithotripsy for urolithiasis.

METHODS

PubMed, Web of Science, Embase, CENTRAL, SinoMed, CNKI database, VIP and Wanfang Database were systematically searched for all relevant clinical trials until September 2023. References were explored to identify the relevant articles. Meta-analysis was carried out for the retrieved studies using RevMan5.4.1 software, and the risk ratio, mean difference and 95% confidence interval were expressed. Statistical significance was set at p < 0.05. The main outcomes of this meta-analysis were stone-free rate (SFR), perioperative outcomes and intraoperative or postoperative complications.

RESULTS

Thirteen studies, including 1394 patients, were included. According to the results of pooled analysis, TFL was associated with significantly higher stone-free rate (SFR) [0.52, 95% CI (0.32, 0.85), P = 0.009], shorter operation time [-5.47, 95% CI (-8.86, -2.08), P = 0.002], and less stone migration [0.17, 95% CI (0.06, 0.50), P = 0.001]. However, there was no significant difference in terms of the laser time, duration of hospital stay, drop of hemoglobin level, total energy, postoperative ureteral stenting, the incidence of intraoperative complications or postoperative complications between TFL and Ho: YAGs.

CONCLUSION

The findings of this study demonstrated several advantages of TFL in terms of higher SFR, shorter operative time and less stone migration.

TRIAL REGISTRATION

The protocol of this systematic review was listed in PROSPERO ( www.crd.york.ac.uk/PROSPERO ) (Protocol number: CRD42022362550).

A retrospective single-center study

PURPOSE

The aim of the present, retrospective study was to describe our initial experience and early outcomes of Thulium Fiber Laser enucleation of the prostate (ThuFLEP) with the use of the FiberDust™ (Quanta System, Samarate, Italy) in patients with benign prostate hyperplasia.

METHODS

From June 2022 to April 2023, all patients who underwent endoscopic enucleation of the prostate at Urology Department of the University Hospital of Patras were included. A single surgeon utilizing the same standardized operative technique performed all the surgeries. The primary endpoints included the uneventful completion of the operation, the surgical time and any minor or major complication observed intra- or post-operatively.

RESULTS

Twenty patients with benign prostate hyperplasia were treated with ThuFLEP. All the surgeries were completed successfully and uneventfully. The enucleation phase of the operation was completed in a mean time of 45±9.1 min, while the average time needed for the morcellation was 17.65±3.42 min. No significant complications were observed intra- or post-operatively. The average hemoglobin drop was calculated to be 0.94±0.71 g/dL.

CONCLUSIONS

All the operations were successfully and efficiently completed with the use of the FiberDust™ (Quanta System, Samarate, Italy) in ThuFLEP. Significant blood loss or major complications were not observed.

Exploring optimal settings for safe and effective thulium fibre laser lithotripsy in a kidney model

OBJECTIVES

To explore the optimal laser settings and treatment strategies for thulium fibre laser (TFL) lithotripsy, namely, those with the highest treatment efficiency, lowest thermal injury risk, and shortest procedure time.

MATERIALS AND METHODS

An in vitro kidney model was used to assess the efficacy of TFL lithotripsy in the upper calyx. Stone ablation experiments were performed on BegoStone phantoms at different combinations of pulse energy (EP ) and frequency (F) to determine the optimal settings. Temperature changes and thermal injury risks were monitored using embedded thermocouples. Experiments were also performed on calcium oxalate monohydrate (COM) stones to validate the optimal settings.

RESULTS

High EP /low F settings demonstrated superior treatment efficiency compared to low EP /high F settings using the same power. Specifically, 0.8 J/12 Hz was the optimal setting, resulting in a twofold increase in treatment efficiency, a 39% reduction in energy expenditure per unit of ablated stone mass, a 35% reduction in residual fragments, and a 36% reduction in total procedure time compared to the 0.2 J/50 Hz setting for COM stones. Thermal injury risk assessment indicated that 10 W power settings with high EP /low F combinations remained below the threshold for tissue injury, while higher power settings (>10 W) consistently exceeded the safety threshold.

CONCLUSIONS

Our findings suggest that high EP /low F settings, such as 0.8 J/12 Hz, are optimal for TFL lithotripsy in the treatment of COM stones. These settings demonstrated significantly improved treatment efficiency with reduced residual fragments compared to conventional settings while keeping the thermal dose below the injury threshold. This study highlights the importance of using the high EP /low F combination with low power settings, which maximizes treatment efficiency and minimizes potential thermal injury. Further studies are warranted to determine the optimal settings for TFL for treating kidney stones with different compositions.

Oncological Outcomes of Thulium-Yttrium-Aluminum-Garnet (Tm:YAG) Laser Ablation for Penile Cancer

OBJECTIVE

To report oncological outcomes after thulium-yttrium-aluminum-garnet (Tm:YAG) laser ablation for penile cancer patients.

MATERIALS AND METHODS

We retrospectively analyzed 71 patients with ≤cT1 penile cancer (2013-2022). All patients underwent Tm:YAG ablation with a RevoLix 200W continuous-wave laser. First, Kaplan-Meier plots and multivariable Cox regression models tested local tumor recurrence rates. Second, Kaplan-Meier plots tested progression-free survival (≥T3 and/or N1-3 and/or M1).

RESULTS

Median (interquartile range) follow-up time was 38 (22-58) months. Overall, 33 (50.5%) patients experienced local tumor recurrence. Specifically, 19 (29%) vs 9 (14%) vs 5 (7.5%) patients had 1 vs 2 vs 3 recurrences over time. In multivariable Cox regression models, a trend for higher recurrence rates was observed for G3 tumors (hazard ratio:6.1; P = .05), relative to G1. During follow-up, 12 (18.5%) vs 4 (6.0%) vs 2 (3.0%) men were retreated with 1 vs 2 vs 3 Tm:YAG laser ablations. Moreover, 11 (17.0%) and 3 (4.5%) patients underwent glansectomy and partial/total penile amputation. Last, 5 (7.5%) patients experienced disease progression. Specifically, TNM stage at the time of disease progression was: (1) pT3N0; (2) pT2N2; (3) pTxN3; (4) pT1N1 and (5) pT3N3, respectively.

CONCLUSION

Tm:YAG laser ablation provides similar oncological results as those observed by other penile-sparing surgery procedures. In consequence, Tm:YAG laser ablation should be considered a valid alternative for treating selected penile cancer patients.

How much energy do we need to ablate 1 cubic millimeter of stone during Thulium Fiber Laser lithotripsy? An in vitro study

INTRODUCTION

Both Holmium:yttrium-aluminium-garnet (Ho:YAG) laser and Thulium Fiber Laser (TFL) can effectively treat all urinary stone types. This in vitro study evaluated the ablation volume per pulse (AVP) and required energy needed to ablate 1mm3 (RE, J/mm3) of various stone types at different laser settings with TFL.

METHODS

272-µm core-diameter laser fibers (Boston Scientific©) were connected to a 50 Watts TFL generator (IPG®). An experimental setup immerged human stones of calcium oxalate monohydrate (COM), uric acid (UA), and cystine (CYS) with a single pulse lasing emission (0.5/0.8/1 J), in contact mode. Stones were dried out before three-dimensional scanning to measure AVP and deduce from the pulse energy (PE) and AVP the RE. A direct comparison with known Ho:YAG's AVP and RE was then carried out.

RESULTS

AVP for COM stones was significantly greater than those for CYS stones and similar to UA stones (p = 0.02 and p = 0.06, respectively). If AVP increased with PE against COM and UA stones, AVP decreased against CYS stones. 1 J PE resulted in a threefold lower RE compared with other PE for COM stones. On the contrary, RE for CYS increased with PE, whereas PE did not had influence on RE for UA. TFL was associated with greater AVP for COM, but lower for UA and CYS stones compared to Ho:YAG laser.

CONCLUSION

This in vitro study firstly describes the ablation volume per pulse and required energy to treat a cubic millimeter of three frequent human stone types, and suggest TFL could not be suited for cystine. Therefore, stone composition could be considered when choosing the laser source for lithotripsy.

Blood concentrations of metals, essential trace elements, rare earth elements and other chemicals in the general adult population of Barcelona: Distribution and associated sociodemographic factors

BACKGROUND

Very little information is available on the population distribution and on sociodemographic predictors of body concentrations of rare earth elements (REE) and other chemicals used in the manufacturing of high-tech devices.

OBJECTIVES

To analyze the distribution and associated sociodemographic factors of blood concentrations of chemical elements (including some metals, essential trace elements, rare earth elements and other minority elements) in a representative sample of the general population of Barcelona (Spain).

METHODS

A sample of participants in the Barcelona Health Survey of 2016 (N = 240) were interviewed face-to-face, gave blood, and underwent a physical exam. Concentrations of 50 chemical elements were analyzed by ICP-MS in whole blood samples.

RESULTS

All 50 chemicals studied, including 26 REE and minority elements, were detected. Lead, silver, arsenic, cadmium, mercury, antimony, strontium, thallium and six essential trace elements were detected in more than 70% of the population. The most frequently detected REE and minority elements were europium (62%), thulium (56%), gold (41%), indium (31%), ruthenium (24%), and tantalum (20%). Less affluent occupational social classes had higher percentages of detection of some REE. Median concentrations of silver, arsenic, cadmium and mercury were: 0.091, 3.01, 0.309, and 3.33 ng/mL, respectively. Women had lower median concentrations than men of lead (1.47 vs. 2.04 μg/dL, respectively), iron and zinc, and higher concentrations of copper and manganese. The influence of sociodemographic characteristics on chemical concentrations differed by sex.

CONCLUSIONS

While well-known contaminants as lead, mercury, cadmium, or arsenic were detected in the majority of the population, numerous individuals had also detectable concentrations of chemicals as europium, indium, thulium, or gold. Sociodemographic and physical characteristics (sex, age, social class, weight change) influenced concentrations of some chemicals.

Experts' recommendations in laser use for the treatment of urolithiasis: a comprehensive guide by the European Section of Uro-Technology (ESUT) and Training-Research in Urological Surgery and Technology (T.R.U.S.T.)-Group

PURPOSE

To identify laser lithotripsy settings used by experts for specific clinical scenarios and to identify preventive measures to reduce complications.

METHODS

After literature research to identify relevant questions, a survey was conducted and sent to laser experts. Participants were asked for preferred laser settings during specific clinical lithotripsy scenarios. Different settings were compared for the reported laser types, and common settings and preventive measures were identified.

RESULTS

Twenty-six laser experts fully returned the survey. Holmium-yttrium-aluminum-garnet (Ho:YAG) was the primary laser used (88%), followed by thulium fiber laser (TFL) (42%) and pulsed thulium-yttrium-aluminum-garnet (Tm:YAG) (23%). For most scenarios, we could not identify relevant differences among laser settings. However, the laser power was significantly different for middle-ureteral (p = 0.027), pelvic (p = 0.047), and lower pole stone (p = 0.018) lithotripsy. Fragmentation or a combined fragmentation with dusting was more common for Ho:YAG and pulsed Tm:YAG lasers, whereas dusting or a combination of dusting and fragmentation was more common for TFL lasers. Experts prefer long pulse modes for Ho:YAG lasers to short pulse modes for TFL lasers. Thermal injury due to temperature development during lithotripsy is seriously considered by experts, with preventive measures applied routinely.

CONCLUSIONS

Laser settings do not vary significantly between commonly used lasers for lithotripsy. Lithotripsy techniques and settings mainly depend on the generated laser pulse's and generator settings' physical characteristics. Preventive measures such as maximum power limits, intermittent laser activation, and ureteral access sheaths are commonly used by experts to decrease thermal injury-caused complications.

Laser safety, warnings, and limits in retrograde intrarenal surgery

OBJECTIVE

To analyze the current information about laser safety in retrograde intrarenal surgery (RIRS), focusing on the two main laser technologies that we use in urology, the holmium:yttrium-aluminum-garnet (Ho:YAG) laser, and the thulium fiber laser (TFL).

METHODS

Narrative overview of the most relevant articles published in MEDLINE and Scopus databases about this subject.

RESULTS

TFL and Ho:YAG laser at similar settings (0.2 J/40 Hz) have similar volume-averaged temperature increase and the average heating rate increase proportionally to laser power, especially when high frequencies are used. Recent preclinical data, comparing both laser technologies at different laser settings, agreed that when the delivered energy increases in expenses of higher frequencies, the thermal damage increases too. Higher frequencies, despite of the rise of temperature in the irrigation medium, can cause accidental thermal lasering lesions.

CONCLUSION

The use of low frequency settings and a proper irrigation is critical to avoid thermal injury in endoscopic laser lithotripsy. In addition, the use of laser safety eyeglasses is recommended in Ho:YAG and TFL ELL.

Use of fractionated laser therapy for the treatment of androgenetic alopecia: a systematic review and meta-analysis

Procedural management, including fractionated laser therapy, has been increasingly investigated for the management of androgenetic alopecia (AGA). However, no comprehensive resources exist detailing the efficacy of fractionated laser therapies used for the treatment of AGA. A systematic review investigating fractionated laser use for AGA was performed, separated into each distinct fractionated laser modality. A meta-analysis was performed to examine improvement in hair counts and hair shaft diameter. Fourteen studies were included for systematic review, which identified the use of erbium-glass, thulium, erbium-ytrrium:aluminum garnet (YAG), and carbon dioxide (CO2) fractionated laser for the treatment of AGA. In the meta-analysis, fractionated laser combination therapy showed significant improvement in hair shaft diameter (2.51, 95% CI 2.37-2.65, I2 = 90.54). Fractionated laser monotherapy alone significantly improved hair shaft diameter (2.28 95% CI 2.03-2.52, I2 = 91.20%). This effect was durable on subgroup analysis for both erbium-glass (2.36 95% CI 2.01-2.71, I2 = 92.05%) and thulium (1.61 95% CI 1.08-2.15, I2 = < 0.00%). There was no improvement in hair shaft count for any laser modality. Erbium-glass laser is an effective modality as either monotherapy or combination with topical/injectable therapies to improve hair shaft diameter in AGA.

Safety, feasibility, and quality of thulium laser en-bloc resection for treatment of non-muscle invasive bladder cancer

BACKGROUND

Trans-Urethral Resection of Bladder Tumors (TURBT) is a critical step in diagnosis, staging and treatment of bladder tumors. Conventional TURBT (cTURBT) involves the electro-resection of the tumor into small fragments. This technique leads to concerns about the completeness of resection, under-staging, bleeding, cancer cell implantation, and most importantly, risk of tumour recurrence. To circumvent this, laser en-bloc resection of bladder tumors has been introduced.

OBJECTIVES

Assessment of the safety, feasibility, and quality of Thulium Laser En-bloc Resection of Tumors (TmL-ERBT) for treatment of Non-Muscle Invasive Bladder Cancer (NMIBC) in various urinary bladder walls as a primary endpoint. The secondary endpoints were to investigate the feasibility of thulium laser use in the re-staging cystoscopy and to evaluate the learning curve of TmL-ERBT.

METHODS

This is a prospective observational study including all newly diagnosed patients, above 18 years old, with a urinary bladder mass ≤ 4 cm in maximal dimension (measured via bladder ultrasound or CT or MRI). All patients underwent TmL-ERBT under regional anaesthesia in a lithotomy position. All intraoperative complications such as obturator nerve reflex, bladder perforation, and significant bleeding were recorded. Postoperative variables such as the mean catheterization time, bladder irrigation fluid volume and duration, and the mean of hospital stay as well as the postoperative complications were recorded. All patients were risk stratified and managed according to EUA guidelines then followed by a surveillance regimen per 3 months for 6 months.

RESULTS

The study included 23 patients with a mean age of 53 ± 15.8 years. While 15 patients (65%) had a single tumor, the rest had multiple tumors, ranging from 2 to 3 in number with a total of 36 lesions. No cases required conversion to cTURBT and none of them experienced obturator nerve reflex or bladder perforation. Only one patient (4.3%) had an attack of clot urine retention. The mean hospitalization time was 31.2 ± 14.4 h and the mean catheterization time was 20.4 ± 13.3 h. The Detrusor muscle was present in 20 patients (87%) and the remaining 3 patients required a re-staging cystoscopy which was performed efficiently using thulium laser. None of the treated patients developed tumour recurrence during the follow-up period. In analysis, the duration of complete resection of 2-4 cm tumours was 23-27 min after the 7th case with a resection rate of 0.12-0.15 cm/min.

CONCLUSION

TmL-ERBT is safe and feasible for complete resection of NMIBC with a short learning curve and adequate cancer control.

An Innovative Technique for Ejaculation-Sparing Prostatic Enucleation with Thulium:YAG Laser

Purpose: We report our experience with 100 patients who underwent an innovative prostate enucleation technique that spares the complete urethral-plate from the veru montanum to the bladder neck using a low-energy thulium laser emission. The aim of our study was to evaluate the short-term effects of this procedure on ejaculation preservation and urinary obstruction. Materials and Methods: The International Prostate Symptom Index (IPSS), quality of life (QoL), and Male Sexual Health Questionnaire Ejaculatory Dysfunction (MSHQ-EJD) Short Form were used as validated instruments to quantify ejaculatory dysfunction before and 6 months after the surgery. Results: The median IPSS score pre- and postoperatively was 20 and 5, respectively (p < 0.0001); QoL dropped from a median of 4-1 (p < 0.0001); and the mean preoperative maximal flow rate improved significantly (8.5 vs 21.2 mL/min) (p < 0.0001). Furthermore, there was significant reduction in postvoid residual postoperatively (p < 0.0001). Postoperative ejaculatory function was preserved in 92/100 patients (92%). According to the MSHQ-EJD score, patients reported a slight nonsignificant decrease in frequency of ejaculation (item 1), force of expulsion (item 2) and reduction in semen volume during ejaculation (item 3), with the exception of ejaculation discomfort (item 4). Conclusion: According to our results, complete removal of the apical tissue, which has been advocated as an integral part of the so called ejaculatory hood, does not interfere with ejaculation if the ventral lissosphincter remains intact.

Thulium fiber laser vs Ho:YAG in RIRS: a prospective randomized clinical trial assessing the efficacy of lasers and different fiber diameters (150 µm and 200 µm)

INTRODUCTION

The aims of the study: (1) to compare the Super Pulse Thulium Fiber Laser (SP TFL) and the holmium: yttrium-aluminium-garnet (Ho:YAG) lasers in retrograde intrarenal surgery (RIRS); (2) to compare the efficacy of SP TFL laser fibers of different diameters (150 μm and 200 μm).

METHODS

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 fiber diameter of 150 μm; (2) SP TFL with 200-μm fiber; and (3) Ho:YAG (Lumenis, USA) with 200-μm fiber.

RESULTS

Ninety-six 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 laser on time (LOT) in the 200-μm SP TFL group was 9.2 (6.2-14.6) min, in 150-μm SP TFL-11.4 (7.7-14.9) min (p = 0.390), in Ho:YAG-14.1 (10.8-18.1) min (p = 0.021). The total energy consumed in 200-μm SP TFL was 8.4 (5.8-15.2) kJ; 150-μm SP TFL - 10.8 (7.3-13.5) kJ (p = 0.626) and in Ho:YAG-15.2 (11.1-25.3) kJ (p = 0.005).

CONCLUSIONS

Irrespective of the density, RIRS with SP TFL laser has proven to be both a safe and effective 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.

Pulsed Thulium:YAG laser - What is the lithotripsy ablation efficiency for stone dust from human urinary stones? Results from an in vitro PEARLS study

BACKGROUND

The novel pulsed thulium:yttrium-aluminum-garnet (p-Tm:YAG) laser was recently introduced. Current studies present promising p-Tm:YAG ablation efficiency, although all are based on non-human stone models or with unknown stone composition. The present study aimed to evaluate p-Tm:YAG ablation efficiency for stone dust from human urinary stones of known compositions.

METHODS

Calcium oxalate monohydrate (COM) and uric acid (UA) stones were subjected to lithotripsy in vitro using a p-Tm:YAG laser generator (Thulio®, Dornier MedTech GmbH, Germany). 200 J was applied at 0.1 J × 100 Hz, 0.4 J × 25 Hz or 2.0 J × 5 Hz (average 10W). Ablated stone dust mass was calculated from weight difference between pre-lithotripsy stone and post-lithotripsy fragments > 250 µm. Estimated ablated volume was calculated using prior known stone densities (COM: 2.04 mg/mm3, UA: 1.55 mg/mm3).

RESULTS

Mean ablation mass efficiency was 0.04, 0.06, 0.07 mg/J (COM) and 0.04, 0.05, 0.06 mg/J (UA) for each laser setting, respectively. This translated to 0.021, 0.029, 0.034 mm3/J (COM) and 0.026, 0.030, 0.039 mm3/J (UA). Mean energy consumption was 26, 18, 17 J/mg (COM) and 32, 23, 17 J/mg (UA). This translated to 53, 37, 34 J/mm3 (COM) and 50, 36, 26 J/mm3 (UA). There were no statistically significant differences for laser settings or stone types (all p > 0.05).

CONCLUSION

To our knowledge, this is the first study showing ablation efficiency of the p-Tm:YAG laser for stone dust from human urinary stones of known compositions. The p-Tm:YAG seems to ablate COM and UA equally well, with no statistically significant differences between differing laser settings.

Thulium:YAG laser: a good compromise between holmium:YAG and thulium fiber laser for endoscopic lithotripsy? A narrative review

PURPOSE

To provide a technological description of the new pulsed solid-state Thulium:YAG laser (Tm:YAG). In addition, current available literature on Tm:YAG lithotripsy is also reviewed.

MATERIALS AND METHODS

Medline, Scopus, Embase, and Web of Science databases were used to search for Tm:YAG operating mode articles.

RESULTS

Tm:YAG technology works with a laser cavity with thulium-doped YAG crystal, pumped by laser diodes. Laser beam operates at 2013 nm, with an adjustable peak power (≥ 1000 W) and the minimal fiber laser diameter is of 200 µm. It has an intermediate water absorption coefficient and peak power-pulse duration. Various pulse modulations are proposed, aiming to minimize stone retropulsion. Multiple comparative in vitro studies suggest that Tm:YAG's ability to fragment stones is similar to the one of the Ho:YAG laser; on the contrary, its ability to dust all stone types is similar to the one of the TFL, with a low retropulsion. A single in vivo study assessed Tm:YAG lithotripsy feasibility.

CONCLUSIONS

The new pulsed solid-state thulium:YAG laser could represent a safe and effective compromise between Ho:YAG laser and TFL for endoscopic lithotripsy, either in retrograde intra-renal surgeries or in percutaneous nephrolithotomy.

Initial experience with the graphical user interface for laser parameters setting of a new thulium fibre laser source device for urinary pathologies treatment

BACKGROUND AND OBJECTIVE

We aimed to evaluate the concordance between the pre-settings ranges of thulium fibre laser (TFL) (Coloplast TFL Drive, Denmark) with easy-to-use graphical user interface and the laser settings used by a high-volume endo-urologist during surgical procedures.

MATERIALS AND METHODS

In October 2022, we prospectively collected data of 67 patients who underwent TFL Drive (Coloplast, Denmark) for the management of urinary stones. Urothelial tumour (upper tract urinary cancer (UTUC) and bladder) 200 and 150 μm laser fibres were used for procedures. Stones characteristics (size and density) tumours and stenosis localizations, laser-on time (LOT), and laser settings were recorded. We also assessed the ablation speed (mm3/s), laser power (W), and Joules/mm3 values for each lithotripsy.

RESULTS

A total 67 patients took part in the study. Median age was 52 (15-81) years. 55 (82%), 8 (12%), and 4 (6%) patients presented urinary stones, urothelial tumour, and stenosis, respectively. Median stone volume was 438 (36-6027) mm3 and median density was 988 (376-2000) HU. Median pulse energy was 0.6 (0.3-1.2), 0.8 (0.5-1) and 1 J for urinary stones, urothelial tumour and stenosis respectably. Endoscopically stone-free rate was 89%. Graphical user interface and surgeon accordance with the safety range were observed in 93.2%, 100% and 100% for urinary stones, UTUC and stenosis, respectively.

CONCLUSION

During endoscopic procedures for urinary stones treatment, it is frequently needed to change laser parameters. These new TFL and GUI technology parameters remained in the pre-set security range in 94.1% of procedures.

Efficacy of skin rejuvenation with a fractional 1927-nm thulium laser alone or combined with a chemical peel: a controlled histopathological preliminary study in a mouse model

Many patients demand minimally invasive treatments for skin rejuvenation, such as nonablative laser and superficial chemical peels. Combination therapy yet has not been studied histopathologically. The purpose of this study is to assess the histopathological efficacy of a 1927-nm thulium laser-assisted salicylic acid (SA) peel in skin rejuvenation. A six-segment table was drawn on the shaved back of C57BL/6 mouse. All segments were irradiated with the thulium laser-different tips and passes were used for specific segments. A 30% SA peel was then applied to the right-hand segments. After treatment, the skin samples were collected from each segment and examined for dermal thickness, collagen density, and melanin content. Greater thickness was seen in the combination therapy group compared with the laser alone group and in those segments receiving more passes with larger beam-sized tip. Collagen density increased in all treated skin segments, irrespective of the group. No adverse events were noted in the treated areas. The sample size was small and mouse skin has histological differences with human skin. The combination of a thulium laser and 30% SA peel has a synergistic effect on dermal thickness, so that can be suggested as a novel skin rejuvenation technique.

In vitro investigation of stone ablation efficiency, char formation, spark generation, and damage mechanism produced by thulium fiber laser

To investigate stone ablation characteristics of thulium fiber laser (TFL), BegoStone phantoms were spot-treated in water at various fiber tip-to-stone standoff distances (SDs, 0.5 ~ 2 mm) over a broad range of pulse energy (Ep, 0.2 ~ 2 J), frequency (F, 5 ~ 150 Hz), and power (P, 10 ~ 30 W) settings. In general, the ablation speed (mm3/s) in BegoStone decreased with SD and increased with Ep, reaching a peak around 0.8 ~ 1.0 J. Additional experiments with calcium phosphate (CaP), uric acid (UA), and calcium oxalate monohydrate (COM) stones were conducted under two distinctly different settings: 0.2 J/100 Hz and 0.8 J/12 Hz. The concomitant bubble dynamics, spark generation and pressure transients were analyzed. Higher ablation speeds were consistently produced at 0.8 J/12 Hz than at 0.2 J/100 Hz, with CaP stones most difficult yet COM and UA stones easier to ablate. Charring was mostly observed in CaP stones at 0.2 J/100 Hz, accompanied by strong spark-generation, explosive combustion, and diminished pressure transients, but not at 0.8 J/12 Hz. By treating stones in parallel fiber orientation and leveraging the proximity effect of a ureteroscope, the contribution of bubble collapse to stone ablation was found to be substantial (16% ~ 59%) at 0.8 J/12 Hz, but not at 0.2 J/100 Hz. Overall, TFL ablation efficiency is significantly better at high Ep/low F setting, attributable to increased cavitation damage with less char formation.

Do Hounsfield Units have any significance in predicting intra- and postoperative outcomes in retrograde intrarenal surgery using Holmium and Thulium fiber laser? Results from the FLEXible ureteroscopy Outcomes Registry (FLEXOR)

PURPOSE

To evaluate outcomes of flexible ureteroscopy for renal stones by comparing hard versus soft stones based on their attenuation on computed tomography (Hounsfield Units-HU).

METHODS

Patients were divided into two groups according to the type of laser employed [Holmium:YAG (HL) or Thulium fiber laser (TFL)]. Residual fragments (RF) were defined as > 2 mm. Multivariable logistic regression analysis was performed to evaluate factors associated with RF and RF needing further intervention.

RESULTS

4208 patients from 20 centers were included. In whole series, age, recurrent stones, stone size, lower pole stones (LPS), and multiple stones were predictors of RF at multivariable analysis and LPS and stone size with RF requiring further treatment. HU and TFL were associated with lesser RF and RF requiring an additional treatment. In HU < 1000 stones, recurrent stones, stone size, and LPS were predictors of RF at multivariable analysis, whereas TFL was less likely associated with RF. Recurrent stones, stone size, and multiple stones were predictors of RF requiring further treatment, while LPS and TFL were associated with lesser RF requiring further treatment. In HU ≥ 1000 stones, age, stone size, multiple stones, and LPS were predictors of RF at multivariable analysis, while TFL was less likely associated with RF. Stone size and LPS were predictors of RF requiring further treatment, whereas TFL was associated with RF requiring further treatment.

CONCLUSION

Stone size, LPS, and use of HL are predictors of RF after RIRS for intrarenal stones regardless of stone density. HU should be considered an important parameter in predicting SFR.

What to expect from the novel pulsed thulium:YAG laser? A systematic review of endourological applications

INTRODUCTION

Several preclinical studies about a novel pulsed-thulium:yttrium-aluminum-garnet (p-Tm:YAG) device have been published, demonstrating its possible clinical relevance.

METHODS

We systematically reviewed the reality and expectations for this new p-Tm:YAG technology. A PubMed, Scopus and Embase search were performed. All relevant studies and data identified in the bibliographic search were selected, categorized, and summarized.

RESULTS

Tm:YAG is a solid state diode-pumped laser that emits at a wavelength of 2013 nm, in the infrared spectrum. Despite being close to the Ho:YAG emission wavelength (2120 nm), Tm:YAG is much closer to the water absorption peak and has higher absorption coefficient in liquid water. At present, there very few evaluations of the commercially available p-Tm:YAG devices. There is a lack of information on how the technical aspects, functionality and pulse mechanism can be maximized for clinical utility. Available preclinical studies suggest that p-Tm:YAG laser may potentially increase the ablated stone weight as compared to Ho:YAG under specific condition and similar laser parameters, showing lower retropulsion as well. Regarding laser safety, a preclinical study observed similar absolute temperature and cumulative equivalent minutes at 43° C as compared to Ho:YAG. Finally, laser-associated soft-tissue damage was assessed at histological level, showing similar extent of alterations due to coagulation and necrosis when compared with the other clinically relevant lasers.

CONCLUSIONS

The p-Tm:YAG appears to be a potential alternative to the Ho:YAG and TFL according to these preliminary laboratory data. Due to its novelty, further studies are needed to broaden our understanding of its functioning and clinical applicability.

Histopathological assessment of depth of coagulation necrosis with Holmium, Moses, and Thulium fiber lasers in human prostate tissue

PURPOSE

To evaluate coagulation necrosis depth (CND) of Holmium (HL), Moses (ML), and Thulium fiber laser (TFL) in ex vivo human prostate tissue at various energy settings.

METHODS

After endoscopic HL enucleation, small prostate tissue fragments were removed from the bladder with graspers and used for study. Immediately after surgery, a single incision was made on the surface of the tissue kept under normal saline at room temperature using a hand-held 550-µm laser fiber. Variable energy settings were tested for all three lasers. Two pathologists measured the CND with light microscopy using ocular micrometer. Impact of various laser settings on CND was analyzed. The differences in CND of all three lasers at similar laser power were compared.

RESULTS

Mean CND was 0.56 ± 0.53 mm for long-pulse HL, 0.54 ± 0.53 mm for ML, 0.67 ± 0.67 mm for low-pulse TFL, and 0.81 ± 0.78 mm for high-pulse TFL. There was no significant difference between mean CND of HL and ML at various laser settings ranging from 10 to 120 W and CND with long- and short-pulse settings of TFL at settings from 10 to 60 W. There was a trend of increasing CND in HL and ML with increasing laser power; however, it was not statistically significant. TFL had similar tissue effects as HL and ML.

CONCLUSION

There is no significant difference in CND of HL, ML, and TFL in ex vivo human prostate tissue. Other factors besides laser type and settings need to be studied to explain clinical differences among various lasers used for prostate enucleation.

Experts' recommendations in laser use for the treatment of upper tract urothelial carcinoma: a comprehensive guide by the European Section of Uro-Technology (ESUT) and Training Research in Urological Surgery and Technology (T.R.U.S.T.) group

PURPOSE

To highlight and compare experts' laser settings during endoscopic laser treatment of upper tract urothelial carcinoma (UTUC), to identify measures to reduce complications, and to propose guidance for endourologists.

METHODS

Following a focused literature search to identify relevant questions, a survey was sent to laser experts. We asked participants for typical settings during specific scenarios (ureteroscopy (URS), retrograde intrarenal surgery (RIRS), and percutaneous treatment). These settings were compared among the reported laser types to find common settings and limits. Additionally, we identified preventive measures commonly applied during surgery.

RESULTS

Twenty experts completed the survey, needing a mean time of 12.7 min. Overall, most common laser type was Holmium-Yttrium-Aluminum-Garnet (Ho:YAG) (70%, 14/20) followed by Thulium fiber laser (TFL) (45%, 9/20), pulsed Thulium-Yttrium-Aluminum-Garnet (Tm:YAG) (3/20, 15%), and continuous wave (cw)Tm:YAG (1/20, 5%). Pulse energy for the treatment of distal ureteral tumors was significantly different with median settings of 0.9 J, 1 J and 0.45 J for Ho:YAG, TFL and pulsed Tm:YAG, respectively (p = 0.048). During URS and RIRS, pulse shapes were significantly different, with Ho:YAG being used in long pulse and TFL in short pulse mode (all p < 0.05). We did not find further disparities.

CONCLUSION

Ho:YAG is used by most experts, while TFL is the most promising alternative. Laser settings largely do not vary significantly. However, further research with novel lasers is necessary to define the optimal approach. With the recent introduction of small caliber and more flexible scopes, minimal-invasive UTUC treatment is further undergoing an extension of applicability in appropriately selected patients.

Flexible ureteroscopy for lower pole calculus: is it still a challenge?

PURPOSE

Flexible ureteroscopy (fURS) is steadily gaining popularity in the management of renal calculi, including those located in the lower pole (LP). Due to difficulty in accessing to the LP of kidney in minority of cases with fURS and reports of lower stone-free rate (SFR), it is still considered as a challenge in selected cases. The purpose of the review was to analyze the various aspects of fURS for LP stones.

METHODS

An extensive review of the recent literature was done including different factors such as anatomy, preoperative stenting, stone size, flexible scopes, types of lasers, laser fibers, suction, relocation, stone-free rates, and complications.

RESULTS

The significance of various lower pole anatomical measurements remain a subject of debate and requires standardization. Recent improvements in fURS such as single-use digital scopes with better vision and flexibility, high power laser, thulium fiber laser, smaller laser fiber, and accessories have significantly contributed to make flexible ureteroscopy  more effective and safer in the management of LP stone. The utilization of thulium fiber lasers in conjunction with various suction devices is being recognized and can significantly improve SFR.

CONCLUSIONS

With the significant advancement of various aspects of fURS, this treatment modality has shown remarkable efficacy and gaining widespread acceptance in management of LP kidney stones. These developments have made the fURS of LP stones less challenging.

Minimizing Thermal Damage During Thulium Laser-Assisted Partial Arytenoidectomy: Pulsed Versus Continuous Cutting in an Ex-Vivo Calf Model

OBJECTIVES

The 2 µm-wavelength thulium laser is an effective cutter during partial arytenoidectomy, but thermal trauma can damage adjacent laryngeal tissue. Pulsing laser energy may reduce trauma when compared to continuous-wave cutting. This study measured temperature changes, thermal trauma, and time to complete partial arytenoidectomy, with and without pulsing, in an ex-vivo calf model.

METHODS

Tissue temperature and time to complete a trans-cartilaginous cut were measured during partial arytenoidectomy on ex-vivo calf vocal folds (N = 24) using a thulium laser in continuous-wave (CW, N = 12) and pulsed-wave (PW, N = 12) modes. Energy was 5 W for CW and PW cuts; pulse-widths were 250, 500, and 750 ms. Thermal damage was analyzed histologically by measuring the depth of lactate dehydrogenase (LDH) inactivation perpendicular to the laser-cut edge at the vocal process. Paired t-tests compared CW and PW modes.

RESULTS

Change in temperature was lower using CW (6.5°C) compared to PW modes (250 ms = 18°; 500 ms = 16°; 750 = 19°; P < .05). Trans-cartilaginous cuts were completed faster using CW (37 seconds) compared to PW (250 ms = 136 seconds; 500 ms = 61 seconds; 750 = 44 seconds; P < .05), and both modes delivered the same total Joules. The average depth of LDH depletion (thermal damage) was similar for all cuts.

CONCLUSIONS

1. Thulium laser cuts in continuous-mode unexpectedly produced less tissue heating yet created similar thermal damage than pulsed-mode cuts during simulated partial arytenoidectomy. 2. Trans-cartilaginous cuts were completed significantly faster in continuous-mode as compared to pulsed-mode cutting. 3. Pulsing the thulium laser does not minimize thermal damage compared to continuous wave cutting during thulium laser-assisted partial arytenoidectomy.

Which Laser System Is Optimal for Cystolithotripsy of Large Bladder Calculi?

Introduction and Objective: A variety of laser sources are available to treat bladder stones. The aim of this study was to compare time and cost efficiency of the thulium fiber laser (TFL) to four holmium lasers (HLs) with different powers or technologies, including MOSES™ during simulated cystolithotripsy. Materials and Methods: In a benchtop simulation of laser cystolithotripsy, 25 identical 4-cm BegoStones (calcium oxalate monohydrate consistency) were placed on a grid within a 3D-printed bladder model. Lasers were operated at maximal energy, using a 550 μm fiber. Lasers compared were as follows: 60 W TFL, 120 W HL with MOSES, and conventional 120, 100, and 30 W HLs. Five trials were performed for each laser with endpoints of laser time, total time, number of fiber strippings, and total energy. Cost-effectiveness was modeled using laser purchase price, fiber, and operating room (OR) time cost. ANOVA with Tukey's B post hoc was performed to compare outcomes. Spearman's test was used to assess correlation between laser power and procedure time. Results: The laser and total operating times were significantly different between the five systems (p < 0.001). The 120 W HL with MOSES was the fastest with 60.9 minutes of laser and 68.3 minutes of procedure times, while the 30 W HL was the slowest with 281.2 minutes of laser and 297.5 minutes of procedure times. The 60 W TFL was faster than the 30 W HL, but slower than the higher power HLs. Higher laser power was associated with shorter procedure time (Rs = -0.98; p = 0.002). When estimating cost per procedure, the MOSES HL was the cheapest, but had the highest purchase cost. The TFL was not cost-effective for large bladder stones compared with the 100 W HL. Conclusions: When treating large bladder stones, total laser power was highly correlated with laser and procedure times and the TFL was limited by its total power. The most cost-effective laser for use will depend on the case volume.

Energy source comparison in en-bloc resection of bladder tumors: subanalysis of a single-center prospective randomized study

PURPOSE

Different energy sources are employed to perform en-bloc transurethral resection of bladder tumor (ERBT). No study compared different energy sources in ERBT. The aim is to compare the different ERBT sources in terms of pathological, surgical and postoperative outcomes.

METHODS

This is a sub-analysis of a prospective randomized trial enrolling patients submitted to ERBT vs conventional TURBT from 03/2018 to 06/2021 (NCT04712201). 180 patients enrolled in ERBT group were randomized 1:1:1 to receive monopolar (m-ERBT), bipolar (b-ERBT) or thulium laser (l-ERBT). Endpoints were the comparison between energies in term of pathological analysis, intra, and post-operative outcomes.

RESULTS

49 (35%) m-ERBT, 45 (32.1%) b-ERBT, and 46 (32.9%) l-ERBT were included in final analysis. The rate of detrusor muscle (DM) presence was comparable between the energies used (p = 0.796) or the location of the lesion (p = 0.662). Five (10.2%), 10 (22.2%) and 0 cases of obturator nerve reflex (ONR) were recorded in m-ERBT, b-ERBT and I-ERBT groups, respectively (p = 0.001). Conversion to conventional TURBT was higher for lesions located in the anterior wall/dome/neck (p < 0.001), irrespective from the energy used. The presence of artifact in the pathological specimen was higher for lesions at the posterior wall (p = 0.03) and trigone (p = 0.03).

CONCLUSIONS

In our study, no difference in staging feasibility among energies was found. Laser energy might be beneficial in lateral wall lesions to avoid ONR. Since there is an increased risk of ERBT conversion to conventional TURBT for lesions of the anterior wall, electrocautery might be preferred over laser to avoid waste of material.

Pulsed thulium:YAG laser-ready to dust all urinary stone composition types? Results from a PEARLS analysis

PURPOSE

To evaluate whether stone dust can be obtained from all prevailing stone composition types using the novel pulsed thulium:YAG (p-Tm:YAG), including analysis of stone particle size after lithotripsy.

METHODS

Human urinary stones of 7 different compositions were subjected to in vitro lithotripsy using a p-Tm:YAG laser with 270 µm silica core fibers (Thulio®, Dornier MedTech GmbH®, Wessling, Germany). A cumulative energy of 1000 J was applied to each stone using one of three laser settings: 0.1 J × 100 Hz, 0.4 J × 25 Hz and 2.0 J × 5 Hz (average power 10 W). After lithotripsy, larger remnant fragments were separated from stone dust using a previously described method depending on the floating ability of dust particles. Fragments and dust samples were then passed through laboratory sieves to evaluate stone particle count according to a semiquantitative analysis relying on a previous definition of stone dust (i.e., stone particles ≤ 250 µm).

RESULTS

The p-Tm:YAG laser was able to produce stone dust from lithotripsy up to measured smallest mesh size of 63 µm in all seven stone composition types. Notably, all dust samples from all seven stone types and with all three laser settings had high counts of particles in the size range agreeing with the definition stone dust, i.e., ≤ 250 µm.

CONCLUSION

This is the first study in the literature proving the p-Tm:YAG laser capable of dusting all prevailing human urinary stone compositions, with production of dust particles ≤ 250 µm. These findings are pivotal for the broader future implementation of the p-Tm:YAG in clinical routine.

En bloc enucleation of the prostate with early apical release using a high-power (200 W) thulium device: studying a learning curve

OBJECTIVE

The aim of this study was to reveal the learning curve of early apical release en bloc laser prostatectomy using a high-power thulium (200 W) laser device.

METHODS

We obtained data on the initial 60 patients who had thulium laser enucleation of the prostate by a single surgeon between October 2021 and August 2022 to treat the signs and symptoms of benign prostatic hyperplasia at our clinic. The cases were split into three groups, each consisting of 20 patients. Prostate volumes, prostate-specific antigen and hemoglobin levels, the International Prostate Symptom Score, Quality of Life scores, the International Index of Erectile Function-5 scores, and uroflowmetry parameters were documented preoperatively. The enucleation weight, the enucleation and morcellation times, as well as the efficiency, hospitalization, and catheterization durations were calculated. The patients were re-evaluated at 6 months postoperatively, examined for functional results, and compared to baseline conditions.

RESULTS

Enucleation times, morcellation times, enucleation weight, and enucleation efficiency were significantly different among the groups. However, there was no statistically significant difference in total operative time and morcellation efficiency. In terms of postoperative statistics, the reduction in hemoglobin was significantly greater in Group 1 compared to Group 2. Six months after surgery, all groups had comparable validated ratings (International Prostate Symptom Score, Quality of Life, and the International Index of Erectile Function-5) on postoperative examinations. There were no long-term complications in either group throughout the perioperative period.

CONCLUSION

Completing 40 first cases would be sufficient for managing the learning curve for early apical release en bloc thulium laser enucleation of the prostate.

Holmium and Thulium Fiber Laser Safety in Endourological Practice: What Does the Clinician Need to Know?

PURPOSE OF REVIEW: To summarise the literature on laser safety during endourological practice. RECENT FINDINGS: Holmium and Thulium Fiber laser are the two main energy sources in the current clinical practice. The latter may have superior properties, but more clinical studies are needed to formally establish this. Laser injury to urothelium is more dependent on user experience rather than laser type. Smaller laser fibres allow for lower intra-renal temperature profiles. Operators should pay close attention to laser technique including maintaining the safety distance concept and only firing the laser when tip is clearly in view. When adjusting laser settings, pay close attention to resultant power given the associated heat changes. Prolonged periods of laser activation are to be avoided for the same reason. Outflow can be manipulated such as with access sheath to mitigate temperature and pressure changes. There is still limited evidence to support the mandate for compulsory use of eye protection wear during laser lithotripsy. Lasers are the gold standard energy source for stone lithotripsy. However, the safe clinical application of this technology requires an understanding of core principles as well as awareness of the safety and technical aspects that can help in protecting patient, surgeon and operating staff.

Outcomes of thulium prostatectomy with "Oyster technique" versus transurethral prostatectomy (TURP): a randomized control trial

PURPOSE

To compare the perioperative and postoperative outcomes between Oyster prostate vaporesection using Tm-YAG laser and the conventional transurethral prostatectomy using monopolar energy.

METHODS

Patients with LUTS with an accumulative size of at least 60 ml were randomly assigned to one of two parallel groups to undergo Tm-YAG laser vaporesection (Group 1) or conventional monopolar transurethral prostatectomy (Group 2). The primary endpoints were the reduction in IPSS and the increase in Qmax postoperatively. Secondary endpoints included the Hemoglobin drop, the complication rate, the changes in urodynamic parameters, the duration of hospitalization and catheterization and the changes in IIEF during the 24-month follow-up.

RESULTS

In total 32 and 30 patients were enrolled in Groups 1 and 2, respectively. Patient age (p = 0.422) and prostate volume were similar among the groups (p = 0.51). The outcomes in terms of IPSS decrease and Qmax amelioration were comparable (p = 0.449 and p = 0.237, respectively). Operative and hospitalization times were lower in Group 1 (p = 0.002 and p = 0.004, respectively). Hemoglobin drop, changes in urodynamic parameters and improvement in IIEF and QoL scores did not differ among the two Groups. The average time with the catheter was 2.06 ± 0.35 and 2.5 ± 0.82 (p = 0.003) days for Group 1 and Group 2, respectively. The overall complication rate was 6.2% for Group 1 and 13.3% for Group 2.

CONCLUSIONS

The Oyster technique leads to similar postoperative outcomes compared to the standard monopolar transurethral prostatectomy. The shorter catheterization, hospitalization and operation time should be considered advantages of the Oyster technique.

Simultaneous thulium laser resection of the prostate and transperineal prostate biopsy in clinically diagnosed metastatic prostate cancer with bladder outlet obstruction

Metastatic prostate cancer (mPCa) patients complicated with bladder outlet obstruction (BOO) are often referred to a urologist. Androgen deprivation therapy (ADT) combined with indwelling catheter usually be the initial management. To retrospectively analysis the safety and efficacy of simultaneous thulium laser resection of the prostate (TmLRP) and transperineal prostate biopsy in metastatic prostate cancer with bladder outlet obstruction. From January 2016 to December 2021, 67 clinically diagnosed mPCa with BOO patients were included in this study. All patients were preoperatively assessed with international prostate symptom score (IPSS), QoL, serum prostate-specific antigen (PSA), prostate volume evaluation by transrectal ultrasound, postvoid residual urine volume (PVR), and maximum flow rate (Qmax). Preoperative and perioperative parameters at 1-, 3-, and 6-month follow-up were also evaluated. All complications were recorded. Simultaneous TmLRP and transperineal prostate biopsy had obvious advantages for clinically diagnosed mPCa patients with BOO, including short overall operation time (52 ± 23.3 min), little hemoglobin decrease (0.6 ± 0.7 g/l), and short hospital stay (average 3.8 days). In addition, simultaneous TmLRP and transperineal prostate biopsy also brought them significant improvement on IPSS, QoL score, Qmax, and PVR volume (P < 0.001) at 1-, 3-, and 6-month follow-up after operation compared to preoperative parameters. Complications were in a low incidence. Simultaneous TmLRP and transperineal prostate biopsy is a bloodless operation with immediate effect and little perioperative complication. Importantly, it is a promising technology in the diagnosis and treatment of clinically diagnosed mPCa patients with BOO.

[Efficacy and safety of superpulse thulium laser lithotripsy in the intracavitary treatment of urinary calculi]

Objective: To evaluate the efficacy and safety of superpulse thulium laser lithotripsy in the intracavitary treatment of urinary calculi. Methods: From May 2021 to July 2022, patients diagnosed with urinary calculi were screened in four medical centers. Those who met the criteria were treated with superpulse thulium fiber laser under endoscope. The patients' perioperative conditions were recorded. The main effective index was stone-free rate (SFR) 4 weeks after operation, the main safety index was the failure rate of the experimental instruments during operation, and the secondary safety index was the incidence rate of perioperative complications. Results: A total of 76 eligible patients completed superpulse thulium fiber laser lithotripsy, with an average age of (52.0±11.1) years, 54 males and 22 females. There were 31 renal stones, 43 ureteral stones and 2 bladder stones. Percutaneous nephrolithotomy was performed in 17 patients. Ureteroscopy lithotripsy/flexible ureteroscopy lithotripsy was performed in 57 patients and transurethral bladder lithotripsy was in 2 patients. The lithotripsy time of all patients was (50.9±31.4) minutes. There was no failure of experimental instruments during the operation. Six patients refused follow-up examination after operation. The incidence of postoperative adverse events was 61.8% (47/76). One patient needed hospitalization due to inguinal hernia after operation, and the rest were classified as Clavien-dindo grade 1-2. The SFR was 94.3% (66/70) at 4 weeks after operation. Conclusion: It is effective and safe to use superpulse thulium fiber laser in the treatment of urinary calculi.

Comparison Between Holmium:YAG Laser with MOSES Technology vs Thulium Fiber Laser Lithotripsy in Retrograde Intrarenal Surgery for Kidney Stones in Adults: A Propensity Score-matched Analysis From the FLEXible Ureteroscopy Outcomes Registry

PURPOSE

We evaluated stone-free rate and complications after flexible ureteroscopy for renal stones, comparing thulium fiber laser and holmium:YAG laser with MOSES technology.

MATERIALS AND METHODS

Data from adults who underwent flexible ureteroscopy in 20 centers worldwide were retrospectively reviewed (January 2018-August 2021). Patients with ureteral stones, concomitant bilateral procedures, and combined procedures were excluded. One-to-one propensity score matching for age, gender, and stone characteristics was performed. Stone-free rate was defined as absence of fragments >2 mm on imaging within 3 months after surgery. Multivariable logistic regression analysis was performed to evaluate independent predictors of being stone-free.

RESULTS

Of 2,075 included patients, holmium:YAG laser with MOSES technology was used in 508 patients and thulium fiber laser in 1,567 patients. After matching, 284 patients from each group with comparable baseline characteristics were included. Pure dusting was applied in 6.0% of cases in holmium:YAG laser with MOSES technology compared with 26% in thulium fiber laser. There was a higher rate of basket extraction in holmium:YAG laser with MOSES technology (89% vs 43%, P < .001). Total operation time and lasing time were similar. Nine patients had sepsis in thulium fiber laser vs none in holmium:YAG laser with MOSES technology (P = .007). Higher stone-free rate was achieved in thulium fiber laser (85% vs 56%, P < .001). At multivariable analysis, the use of thulium fiber laser and ureteral access sheath ≥8F had significantly higher odds of being stone-free. Lasing time, multiple stones, stone diameter, and use of disposable scopes showed significantly lower odds of being stone-free.

CONCLUSIONS

This real-world study favors the use of thulium fiber laser over holmium:YAG laser with MOSES technology in flexible ureteroscopy for renal stones by way of its higher single-stage stone-free rate.

A multicentric non-randomized prospective observational study on the clinical efficiency of thulium fibre laser in large volume stones (> 1000 mm3)

PURPOSE

Our objective was to analyse the clinical efficiency of TFL in large volume stones during retrograde intrarenal surgery.

MATERIALS AND METHODS

Patients with large volume renal stones (> 1000 mm3) operated at two different centres, from May 2020 to April 2021, were enrolled in this study. Retrograde intrarenal surgery was performed using 60W Superpulse thulium fibre laser™ (IPG Photonics, Russia). Demographic data, stone parameters, laser time, and total operating time were recorded, and laser efficacy (J/mm3) and ablation speed (mm3/s) were calculated. NCCT KUB was done at 3 months postoperatively to calculate stone-free rate.

RESULTS

A total of 76 patients were included and analysed in the study. Mean stone volume was 1753.12 ± 1245.81 (1169.27-2193.25) mm3, mean stone density was 1104.46 ± 313.09 (875.00-1317.00) HU, mean laser time was 537.79 ± 689.89 (21.00-1080.00) sec, mean operating time was 43.38 ± 12.96 (35.00-51.25) min, mean laser efficacy was 20.30 ± 15.5 (8.88-25.57) J/mm3, and mean ablation speed was 1.32 ± 0.7 (0.82-1.64) mm3/sec. A strong positive correlation was found between the stone volume and ablation speed (r = 0.659, p = 0.000), and a moderate negative correlation was found between the stone volume and laser efficacy (J/mm3) (r = - 0.392, p = 0.000). With increasing volume of the stone, J/mm3 decreased significantly and ablation speed increased significantly (p < 0.001). Complications occurred in 21.05% (16/76) patients, most of which were Clavien grades 1-2. Overall SFR is 96.05%.

CONCLUSION

Laser efficiency increases at higher stone volumes (> 1000 mm3), as less energy is required to ablate every mm3 of stone.

Lasers for stone lithotripsy: advantages/disadvantages of each laser source

PURPOSE

The purpose of this article was to make a narrative review of the literature in search of all articles regarding thulium:yttrium-aluminium-garnet (YAG), thulium laser fiber (TFL) and holmium:YAG (Ho:YAG) for lithotripsy from 2020 to 2023. A selection of articles of special interest and best evidence was made in order to give a better perspective on their advantages and disadvantages.

RECENT FINDINGS

New Ho:YAG technologies of as high power, high frequency and pulsed modulations have shown promising results for lithotripsy by reducing retropulsion with good ablation efficiency. High peak power makes it particularly good for percutaneous nephrolithotomy. High intrarenal temperatures and correct setting are still concerning points.TFL has arrived to be one of the main players in flexible ureteroscopy. Being highly efficient and quick, and by producing micro-dusting the laser is quickly heading to become a gold standard. The new pulsed Thulium YAG is the newest laser. For now, only in-vitro studies show promising results with efficient lithotripsy. As the peak power lies between Ho:YAG and TFL it may be able to adequately perform when needing and low power lithotripsy.

SUMMARY

Several new technologies have been developed in the last years for stone lithotripsy. All being efficient and safe if well used. Different advantages and disadvantages of each laser must be taken into consideration to give each laser the proper indication.

Perioperative Outcome of Thulium Laser Enucleation of the Prostate versus Robot-Assisted Simple Prostatectomy: A Propensity Score-Matched Analysis

INTRODUCTION

The aim of this study was to investigate and compare clinical safety and efficiency of Thulium laser enucleation of the prostate (ThuLEP) and robot-assisted simple prostatectomy (RASP) for the treatment of large gland benign prostatic hyperplasia in a tertiary care center.

METHODS

Perioperative data of 39 patients who underwent RASP in our institution from 2015 to 2021 was collected. Propensity score matching using prostate volume, patient age, and body mass index (BMI) was performed from a database of 1,100 Patients treated by ThuLEP from 2009 to 2021. A total of 76 patients were matched. Preoperative parameters such as BMI, age, and prostate volume, as well as intra- and postoperative parameters such as operation time, resection weight, transfusion rate, postoperative catheterization time, length of hospital stay (LoS), hemoglobin drop, postoperative urinary retention (PUR), Clavien-Dindo Classification (CDC), and the Combined Complication Index (CCI), were evaluated.

RESULTS

There was no difference in mean hemoglobin drop (2.2 vs. 1.9 g/dL, p = 0.34), yet endoscopic surgery showed superiority in mean operation time (109 vs. 154 min, p < 0.001), mean postoperative catheterization time (3.3 vs. 7.2 days, p < 0.001), and mean LOS (5.4 vs. 8.4 days, p < 0.001). Complication rates evaluated by CDC (p = 0.11) and CCI (p = 0.89) were similar in both groups. Within the documented complications, transfusion rate (0 vs. 3, p = 0.08) and the occurrence of PUR (1 vs. 2, p = 0.5) showed no significant difference.

CONCLUSION

ThuLEP and RASP show similar perioperative efficacy and a low rate of complications. ThuLEP had shorter operation times, shorter catheterization time, and a shorter LoS.

Vaginoscopy With Laser Treatment of Symptomatic Upper Vaginal Mesh Exposure After Prior Mesh Sacrocolpopexy

OBJECTIVE

To describe the technique of vaginoscopy with Holmium:YAG and Thulium laser treatment of upper vaginal mesh exposure after mesh sacrocolpopexy (MSC) as well as evaluate treatment efficacy.

METHODS

Following IRB approval, a chart review of all patients who underwent laser treatment of upper vaginal mesh exposure during vaginoscopy at a single institution between 2013 and 2022 was performed. Demographic information, previous mesh placement history, presenting symptoms, physical examination and vaginoscopy findings, imaging, laser type and settings, operating time, complications, and follow-up including examination and office vaginoscopy findings were extracted from electronic medical records.

RESULTS

Five patients and 6 surgical encounters were identified. All patients had a history of MSC and symptomatic mesh exposure at the vaginal apex, which was tented up and difficult to access by traditional transvaginal mesh excision. Five patients underwent vaginal mesh treatment with laser with no further vaginal mesh exposure on follow-up exam or vaginoscopy. One patient was found to have a small recurrence at 4 months and underwent a second treatment with negative findings on vaginoscopy 7.9 months post-operatively. There were no complications.

CONCLUSION

Vaginoscopy using a rigid cystoscope and laser treatment of upper vaginal mesh exposure using a Holmium:YAG or Thulium laser is a safe and quick method which led to definitive symptom resolution.

Pulsed thulium laser blood vessel haemostasis as an alternative to bipolar forceps during neurosurgical tumour resection

Due to wavelength-specific water absorption, infrared lasers like the thulium laser emitting at 1940 nm wavelength proved to be suitable for coagulation in neurosurgery. Commonly bipolar forceps used for intraoperative haemostasis can cause mechanical and thermal tissue damage, whilst thulium laser can provide a tissue-gentle haemostasis through non-contact coagulation. The aim of this work is a less-damaging blood vessel coagulation by pulsed thulium laser radiation in comparison to standard bipolar forceps haemostasis. Ex vivo porcine blood vessels in brain tissue (0.34 ± 0.20 mm diameter) were irradiated in non-contact with a thulium laser in pulsed mode (1940 nm wavelength, 15 W power, 100-500 ms pulse duration), with a CO2 gas flow provided simultaneously at the distal fibre tip (5 L/min). In comparison, a bipolar forceps was used at various power levels (20-60 W). Tissue coagulation and ablation were evaluated by white light images and vessel occlusion was visualised by optical coherence tomography (OCT) B-scans at a wavelength of 1060 nm. Coagulation efficiency was calculated by means of the quotient of the difference between the coagulation and ablation radius to the coagulation radius. Pulsed laser application achieved blood vessel occlusion rate of 92% at low pulse duration of 200 ms with no occurrence of ablation (coagulation efficiency 100%). Bipolar forceps showed an occlusion rate of 100%, however resulted in tissue ablation. Tissue ablation depth with laser application is limited to 40 μm and by a factor of 10 less traumatising than with bipolar forceps. Pulsed thulium laser radiation achieved blood vessel haemostasis up to 0.3 mm in diameter without tissue ablation and has proven to be a tissue-gentle method compared to bipolar forceps.

Comparison of Superpulse Thulium Fiber Laser vs Holmium Laser for Ablation of Renal Calculi in an In Vivo Porcine Model

Introduction and Objectives: We sought to compare the effectiveness and efficiency of the superpulse thulium fiber laser (sTFL to the holmium: yttrium-aluminum-garnet [Ho:YAG] laser for ureteroscopic "dusting" of implanted renal stones in an in vivo porcine model. Methods: Twenty-four porcine kidneys (12 juvenile female Yorkshire pigs) were randomized to Ho:YAG or sTFL treatment groups. Canine calcium oxalate stones were scanned with computed tomography to calculate stone volume and stone density; the stones were randomized and implanted into each renal pelvis via an open pyelotomy. In all trials, a 14F, 35 cm ureteral access sheath was placed. With a 9.9F dual lumen flexible ureteroscope, laser lithotripsy was performed using dusting settings: Ho:YAG 200 μm laser fiber at 16 W (0.4 J, 40 Hz) or sTFL 200 μm laser fiber at 16 W (0.2 J, 80 Hz). Lithotripsy continued until no fragments over 1 mm were observed. No stone basketing was performed. Throughout the procedures, intrarenal and renal pelvis temperatures were measured using two percutaneously positioned K-type thermocouples, one in the upper pole calyx and one in the renal pelvis. After the lithotripsy, the ureteropelvic junction was occluded, the kidneys were bivalved, and all residual fragments were collected, dried, weighed, and then measured with an optical laser particle sizer. Results: Implanted stones were similar in volume and density in both groups. Intraoperative collecting system temperatures were similar for both groups (all <44°C). Compared to Ho:YAG, sTFL ablated stones faster (9 vs 27 minutes, p < 0.001) with less energy expenditure (8 vs 26 kJ, p < 0.001), and a greater stone clearance rate (73% vs 45%, p = 0.001). After sTFL lithotripsy, 77% of the remaining fragments were ≤1 mm vs 17% of fragments ≤1 mm after Ho:YAG treatment (p < 0.001). Conclusions: In an in vivo porcine kidney, using dusting settings, sTFL lithotripsy resulted in shorter ablation times, higher stone clearance rates, and markedly smaller stone fragments than Ho:YAG lithotripsy.