Comparison of Holmium:YAG and Thulium Fiber lasers on soft tissue : an ex vivo study

Long-term results of retrograde endopyelotomy: a narrative review

PURPOSE

Retrograde endopyelotomy has emerged as a minimally invasive alternative for treating ureteropelvic junction obstruction (UPJO), characterized by impaired urinary transport due to intrinsic or extrinsic factors. This narrative review evaluates the long-term outcomes of retrograde endopyelotomy, focusing on effectiveness, safety, complications, and reoperation requirements.

METHODS

A systematic search of PubMed, Google Scholar, and Scopus from 1990 to March 2024 identified 29 studies comprising 1238 adult patients.

RESULTS

Findings indicate that retrograde endopyelotomy, predominantly performed using Holmium:YAG lasers, achieved a mean success rate of 76.9%, with variability based on the type of obstruction and intervention methods. Success was inconsistently defined across studies, ranging from symptom resolution to imaging-based criteria. Complication rates averaged 12.5%, with urinary tract infections being the most common. Hospital stays were typically brief, with most patients discharged within 1-3 days.

CONCLUSION

Retrograde endopyelotomy, has the advantage of shorter recovery times and reduced invasiveness compared to open or laparoscopic approaches. Future studies should also explore advancements in laser technology, such as Thulium Fiber Laser, to optimize outcomes.

Initial experience of thulium fiber laser in retrograde intrarenal surgery for ureteral and renal stones in Japan: surgical outcomes and safety assessment compared with holmium: yttrium-aluminum-garnet with MOSES technology

BACKGROUND

Thulium fiber laser (TFL) has been used for the treatment of ureteral and renal stones in Japan since October 2023. However, there are no reports on the initial results of TFL in Japan. This study aimed to assess the initial results of TFL in retrograde intrarenal surgery (RIRS) and to compare them with those of holmium: yttrium-aluminum-garnet (Ho: YAG) laser with MOSES technology.

METHODS

This retrospective single-center study compared perioperative results, complications, and the "stone-free" rate (defined as ≤ 2 mm fragments on computed tomography 1 month after RIRS) between the TFL (60 W) (group A, n = 48) and Ho: YAG laser with MOSES technology (120 W) (group B, n = 48) laser. The inclusion criteria were renal or ureteral stones ≤ 20 mm in diameter and those scheduled for single-stage RIRS.

RESULTS

The two groups had similar baseline patient characteristics. No significant differences were found in operative time (45 vs. 54 min, P = 0.10), laser time (15 vs. 10 min, P = 0.12), stone-free rate (97.9% vs. 95.8%, P = 1.00), ureteral injury (2.1% vs. 8.3%, P = 0.36), or postoperative fever (0% vs. 4.2%, P = 0.49) between groups A and B. However, significant differences were found in basketing time (7 vs. 21 min, P < 0.01) between groups A and B.

CONCLUSIONS

Our study showed that RIRS with TFL had similar results and no difference in complications compared to RIRS with Ho: YAG laser with MOSES technology. The TFL had a significantly shorter basketing time than the Ho: YAG laser with MOSES technology. Furthermore, future research is needed to determine suitable laser settings for the TFL.

An ex vivo experimental study comparing the effects of the holmium: yttrium-aluminum-garnet and thulium fiber lasers on testicular tissue

The effects of lasers on testicular tissue have not yet been investigated in detail. In this experimental ex vivo study, we aimed to demonstrate and compare the effects of the holmium:yttrium-aluminum-garnet (Ho:YAG) and thulium fiber laser (TFL) lasers on testicular tissue. An ex vivo experiment was performed using calf testes. A 100W Ho:YAG laser and a 60W TFL devices with a setting spectrum at 10-60W, a frequency of 20-40 Hz, energy levels at 0.5-1-1.5 J, and medium pulse duration were tested. Histopathological parameters such as Incision depth (ID), vaporization area (VA), coagulation area (CA), and total laser area (TLA = VA + CA) were evaluated. In testicular tissue without a tunica layer, a statistically significant difference was found in the mean VA and TLA values between the Ho:YAG and TFL, in favor of Ho:YAG (p = 0.003, p = 0.003, respectively). In testicular tissue with a tunica layer, there was a statistically significant difference in mean VA, CA, TLA, ID values between Ho:YAG and TFL, in favor of Ho:YAG (all p < 0.001). At 1.5 J-20 Hz and 1.5 J-40 Hz, we observed that the features indicating tissue dissection, such as VA and ID, were lower in the TFL than those in Ho:YAG, while CA values were higher. VA, CA, TLA, ID values were significantly increased in tissue with tunica compared to non-tunicated tissue in both the Ho:YAG and TFL applications. At 30W and 60W, the penetrative effect of the TFL on tissue was less than that of the Ho:YAG, but its coagulation property was superior. What is Known: • Ho:YAG and TFL lasers are widely used in urology, primarily for stone and prostate surgeries, with established tissue effects in these contexts. What is New: • This study is the first to examine and compare the histopathological effects of these lasers on testicular tissue, providing insights into their potential applications in testicular surgery.

Holmium: YAG laser enucleation of the prostate using the new cyber Ho generator with magneto technology: does it provide any advantages compared to thulium: YAG prostate enucleation?

PURPOSE

To assess differences in efficacy and safety between Thulium:YAG laser enucleation of the prostate (ThuLEP) and enucleation performed with the Holmium:YAG Cyber Ho laser generator (HoLEP) with Magneto technology (Quanta System®).

METHODS

Patients with surgical indication for benign prostatic hyperplasia underwent ThuLEP using Cyber TM generator (Group A) versus HoLEP using Cyber Ho generator with Magneto technology (Group B). In Group A settings were 100W for enucleation and 35W for coagulation. In Group B early apical detachment and coagulation were performed with energy 1 J and frequency 30 Hz by applying Magneto technology. Enucleation was performed with energy 2 J and frequency 40 Hz by applying Virtual Basket pulse modulation.

RESULTS

200 patients were enrolled (100 patients per group). Preoperative features were comparable. Mean prostate size was 78.9 vs. 80.5 ml in Group A vs. B (p = 0.09). Mean operative time was 70.6 vs. 64.3 min (p = 0.13) with mean enucleation time 48.8 vs. 43.7 min (p = 0.21) and morcellation time 21.2 vs. 14.6 min (p = 0.03) in ThuLEP vs. HoLEP group. Micturition improvements were comparable. Postoperative gross haematuria was significantly more frequent after ThuLEP and clots-induced urinary retention occurred in 5.0% of cases, compared to no cases after HoLEP (p = 0.02).

CONCLUSIONS

HoLEP using the Cyber Ho generator with the application of Magneto technology for coagulation seems to provide an haemostatic advantage compared to ThuLEP, suggested by the significantly shorter morcellation time, higher morcellation efficiency and lower rate of postoperative gross haematuria and clots-induced urinary retention. Functional outcomes are comparable.

Exploring the optimal parameter settings of a thulium fiber laser during soft tissue resection

There is a lack of clinical consensus on the parameter settings of the pulsed-wave thulium fiber laser for soft tissue resection. The aim of this study was to explore the optimal parameter settings of the pulsed-wave thulium fiber laser for soft tissue resection, with a view to providing a reference for future clinical applications. Two different thulium fiber lasers, prototype thulium fiber lasers and Urolase, were used to explore the optimal parameters of thulium fiber laser for soft tissue cutting by evaluating the depth of tissue vaporization and depth of thermal damage in an isolated pig kidney model, and then the optimal parameters of in vitro screening were statistically validated by operation time, coagulation time, intraoperative hemorrhage, smoke level, and depth of thermal damage in an in vivo model using rabbit kidney. In ex vivo animal experiments the depth of tissue vaporization and thermal damage increased with increasing average power, and tissue carbonization occurred at 30 W. In animal use we used 1 J, 25 W for surgery, and there was no statistical difference between the two thulium fiber lasers in terms of surgery time, coagulation time, bleeding, smoke level, and depth of thermal damage. Thulium fiber laser for soft tissue resection is safe and feasible, and we believe that 1 J, 25 W is the optimal laser setting parameter for soft tissue resection, but it needs to be adjusted according to the actual situation.

Thulium Fiber Versus Holmium:Yttrium-aluminum-garnet Laser for Endoscopic Enucleation of the Prostate: A Systematic Review and Meta-analysis

BACKGROUND AND OBJECTIVE

Thulium fiber laser (TFL) emerged as a competitor of holmium:yttrium-aluminum-garnet (Ho:YAG) laser for anatomic enucleation of the prostate (AEEP) in men with lower urinary tract symptoms (LUTS) related to benign prostatic obstruction (BPO). The aim was to compare the surgical outcomes of Ho:YAG and TFL for AEEP.

METHODS

A literature search was conducted to identify reports published from inception until January 2024. The Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines were followed to identify eligible studies. The coprimary outcomes were the postoperative International Prostate Symptom Score (IPSS), IPSS-Quality of Life (IPSS-QoL), and peak urinary flow (Qmax).

KEY FINDINGS AND LIMITATIONS

Five studies met our inclusion criteria, and data from 1287 and 1555 patients who underwent AEEP with Ho:YAG (holmium laser enucleation of the prostate [HoLEP]) and TFL (thulium fiber laser enucleation of the prostate [ThuFLEP]), respectively, were reviewed. ThuFLEP was associated with a better IPSS at 3 mo even if the difference was not clinically significant (mean difference [MD] 0.59, 95% confidence interval [CI]: 0.29-0.88; p < 0.001). No difference was found for IPSS at 6-12 mo (p = 0.9), and IPSS-QoL at 3 mo (p = 0.9) and 6-12 mo (p = 0.2). HoLEP was associated with a better Qmax at 3 mo (MD 1.41 ml/s, 95% CI: 0.51-2.30; p = 0.002) and ThuFLEP at 6-12 mo (MD -2.61 ml/s, 95% CI: -4.68 to 0.59; p = 0.01), but the differences were not clinically significant. No difference was found in the major (p = 0.3) and overall (p = 0.3) complication rates. HoLEP was associated with shorter enucleation (MD -11.86, 95% CI: -22.36 to 1.36; p = 0.03) but not total operative time (p = 0.5).

CONCLUSIONS AND CLINICAL IMPLICATIONS

The present review provides the most updated evidence on the impact of Ho:YAG and TFL in AEEP, demonstrating that these two energy sources are effective in relieving bothersome LUTS in men with BPO.

PATIENT SUMMARY

Thulium fiber laser is a new energy source that can be used safely for performing endoscopic enucleation of the prostate in men with bothersome symptoms associated with benign prostatic enlargement.

The Recurrence Rates at Three Years for the Conservatively Managed UTUC Cases Using NBI-Assisted Flexible Ureteroscopy and Holmium Laser Vaporization

Background and Objectives: This study aimed to evaluate the recurrence rates at three years for upper tract urothelial carcinoma (UTUC) cases managed conservatively, using Narrow Band Imaging (NBI)-assisted flexible ureteroscopy and Holmium laser vaporization. Materials and Methods: The study group included 61 patients who were diagnosed with NBI-assisted visualization with superficial pyelo-calyceal urothelial tumor lesions, treated conservatively by the flexible ureteroscopic approach and Holmium laser vaporization, also assisted by NBI. This was compared with a control group with the same number of cases, which underwent the same procedure, but without NBI technology. Recurrence rates, the rate of patients who underwent nephroureterectomy, and cancer-specific survival were compared. Results: The relapse rate at 1 year was 3.3% in the study group, and respectively 8.2% in the control group (p < 0.05). Depending on the histological characteristics, at 1 year the relapse rates in the study group were 1.8% in patients with low-grade tumors and 20% in those with high-grade tumors. At 3 years, the relapse rate was 11.5% in the study group versus 18% in the control group, (p < 0.05): 7.1% in patients with low-grade lesions and 40% in patients with high-grade lesions versus 21.4% in patients with low-grade lesions and 100% in patients with high-grade lesions (both arms with statistically significant differences, p < 0.05). Cancer-specific survival was 93.4% in the study group versus 86.9% in the control group (p < 0.05). Conclusions: The recurrence rates at three years for the UTUC cases managed conservatively, using NBI-assisted flexible ureteroscopy and Holmium laser vaporization, were lower than in patients treated by the same technique without NBI assistance, both in low- and high-grade tumors. Cancer-specific survival was also significantly improved by the association of NBI visualization during diagnosis and laser vaporization.

Comparison of holmium:yttrium-aluminium-garnet (YAG), thulium fiber laser, and pulsed thulium:YAG lasers on soft tissue: an ex vivo study

OBJECTIVES

To assess laser-tissue interactions through ablation, coagulation, and carbonisation characteristics in a non-perfused porcine kidney model between three pulsed lasers: holmium (Ho): yttrium-aluminium-garnet (YAG), thulium fiber laser (TFL), and pulsed thulium (p-Tm):YAG.

MATERIALS AND METHODS

A 150-W Ho:YAG, a 60-W TFL, and a 100-W p-Tm:YAG lasers were compared. The laser settings that can be set identically between the three lasers and be clinically relevant for prostate laser enucleation were identified and used on fresh, unfrozen porcine kidneys. Laser incisions were performed using stripped laser fibers of 365 and 550 μm, set at distances of 0 and 1 mm from the tissue surface at a constant speed of 2 mm/s. Histological analysis evaluated shape, depth, width of the incision, axial coagulation depth, and presence of carbonisation.

RESULTS

Incision depths, widths, and coagulation zones were greater with Ho:YAG and p-Tm:YAG lasers than TFL. Although no carbonisation was found with the Ho:YAG and p-Tm:YAG lasers, it was common with TFL, especially at high frequencies. The shapes of the incisions and coagulation zones were more regular and homogeneous with the p-Tm:YAG laser and TFL than with Ho:YAG laser. Regardless of the laser used, short pulse durations resulted in deeper incisions than long pulse durations. Concerning the distance, we found that to be effective, TFL had to be used in contact with the tissue. Finally, 365-μm fibers resulted in deeper incisions, while 550-μm fibers led to wider incisions and larger coagulation zones.

CONCLUSION

Histological analysis revealed greater tissue penetration with the p-Tm:YAG laser compared to the TFL, while remaining less than with Ho:YAG. Its coagulation properties seem interesting insofar as it provides homogeneous coagulation without carbonisation, while incisions remained uniform without tissue laceration. Thus, the p-Tm:YAG laser appears to be an effective alternative to Ho:YAG and TFL lasers in prostate surgery.

Comparison of the effects of Ho: YAG laser virtual Basket™ pulse modulation and Thulium fiber laser on kidney tissue - an ex vivo experimental study

Through an ex vivo experimental study, we aimed to compare the effects of the Ho: YAG laser Virtual Basket (VB™) modulation and a Thulium fiber laser (TFL) on kidney tissue in different environments and using laser configurations. The 100 W Ho: YAG (Cyber Ho, Quanta System, Italy) and 60 W TFL (Fiber Dust, Quanta System, Italy) laser devices were used. The following laser settings were selected: power in the range of 10-60 W, frequency of 20-40 Hz, and energy of 0.5-1-1.5 J. A medium pulse duration of 600 µsec was used for VB™, while short (spdTFL; 50 µsec) and long (lpdTFL; 15,000 µsec) were used for TFL. The tissue's incision depth (ID), vaporization area (VA), coagulation area (CA), total laser area (TLA = VA + CA), surface section (SS), and lateral effect (LE) were measured. In total, 108 experiments were conducted. No statistically significant difference in mean VA, TLA, ID, LE, or SS was observed between VB™, spdTFL, and lpdTFL in the low-power output group in saline (p > 0.05). However, the mean CA was statistically significantly higher for VB™ (p = 0.005). In saline and high-power output group, the mean VA, CA, TLA, LE, and ID were higher when using lpdTFL than other pulse durations (p = 0.001, p = 0.001, p = 0.001, p = 0.006, and p = 0.001, respectively). Similar to lpdTFL, VB™ may provide controlled dissection and incision as well as haemostasis. At different laser settings, the individual effects of laser properties (such as pulse length, energy and frequency) on tissue may be more significant.

Propensity score-matched analysis comparing perioperative, functional, and safety outcomes between thulium fiber laser and bipolar enucleation of the prostate performed by a single surgeon with two years of follow-up

PURPOSE

To compare perioperative, functional, and safety outcomes between thulium fiber laser enucleation of the prostate (ThuFLEP) and bipolar enucleation of the prostate performed by a single surgeon with use of propensity score (PS)-matched analysis.

MATERIALS AND METHODS

Data were from 675 patients, 422 of whom underwent ThuFLEP and bipolar enucleation by a single highly experienced surgeon. ThuFLEP was performed with Fiberlase U1 (IRE Polus Ltd.). Perioperative parameters, safety, and functional outcomes, such as International Prostate Symptom Score (IPSS), quality of life (QoL), postvoid residual volume (PVR), and maximum urinary flow rate (Qmax) were assessed. To control for selection bias, a 1:1 PS-matched analysis was carried out using the following variables as covariates: total prostate volume, preoperative IPSS and early sphincter release.

RESULTS

Of 422 patients, 370 (87.7%) underwent ThuFLEP and 52 (12.3%) underwent bipolar enucleation. Operation, enucleation, and morcellation time were comparable between groups before and after PS-matched analysis (p=0.954, p=0.474, p=0.362, respectively). Functional parameters (IPSS, QoL, PVR, Qmax) were also comparable between groups at every time point before and after PS matching. Significant improvements in IPSS, QoL score, Qmax, and PVR were observed during the 24-month follow-up period for both ThuFLEP and bipolar enucleation without any significant differences between groups. Early and late postoperative complications before and after PS-matched analysis were similar.

CONCLUSIONS

ThuFLEP was comparable to bipolar enucleation in perioperative characteristics, improvement in voiding parameters, and complication rates. Both procedures were shown to be effective and safe in the management of benign prostatic hyperplasia.

Endoscopic enucleation of the prostate with Thulium Fiber Laser (ThuFLEP). 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.

Thulium fiber laser vs. holmium laser enucleation of the prostate: results of a prospective randomized non-inferiority trial

PURPOSE

Holmium laser enucleation of the prostate (HoLEP) represents the current standard procedure for size-independent surgical therapy of benign prostatic obstruction (BPO). With advent of the novel laser technology thulium fiber laser (TFL), we hypothesized that the functional outcome of TFL enucleation of the prostate (ThuFLEP) is non-inferior compared to HoLEP.

METHODS

From October 2021 to October 2022, 150 patients with BPO were recruited for the prospective randomized trial in accordance with CONSORT. Stratified randomization into the arms ThuFLEP (n = 74) or HoLEP (n = 76) was carried out. The primary endpoint was non-inferior international prostate symptom score (IPSS) and quality of life (QoL) at three months after treatment. Secondary endpoints were rates of complications, peak flow, residual urine and operation times.

RESULTS

Preoperative characteristics showed no significant differences. Overall IPSS and QoL improved from 21 to 8 and 4 to 1.5, respectively, after three months of follow-up. No statistically significant differences between ThuFLEP and HoLEP were observed regarding median postoperative IPSS (8.5 vs. 7, p > 0.9), QoL (1 vs. 2, p = 0.6), residual urine (48 vs. 30ml, p = 0.065) and peak flow (19 vs. 17ml/s, p > 0.9). Similarly, safety profile was comparable with no statistically significant differences regarding rate of major complications (5.3 vs. 5.4%, p = 0.5), laser hemostasis time (3 vs. 2min, p = 0.2), use of additive electric coagulation (74 vs. 87%, p = 0.06) or electric coagulation time (8 vs. 8min, p = 0.4).

CONCLUSIONS

In this prospective, randomized trial ThuFLEP showed non-inferior results compared to HoLEP in terms of functional outcomes measured by IPSS and QoL as primary endpoint.

TRIAL REGISTRATION NUMBER

DRKS00032699 (18.09.2023, retrospectively registered).

Relevant parameters for laser surgery of soft tissue

In recent years, the laser has become an important tool in hospitals. Laser surgery in particular has many advantages. However, there is still a lack of the understanding of the influence of the relevant parameters for laser surgery. In order to fill this gap, the parameters pulse frequency, use of an exhaustion system, air cooling, laser power, laser scan speed, laser line energy and waiting time between cuts were analysed by ANOVA using inter-animal variation as a benchmark. The quality of the cuts was quantized by a previously published scoring system. A total of 1710 cuts were performed with a [Formula: see text] laser. Of the parameters investigated, laser power and scan speed have the strongest influence. Only the right combination of these two parameters allows good results. Other effects, such as the use of pulsed or continuous wave (CW) laser operation, or air cooling, show a small or negligible influence. By modulating only the laser power and scan speed, an almost perfect cut can be achieved with a [Formula: see text] laser, regardless of the external cooling used or the laser pulse duration or repetition rate from CW to nanosecond pulses.

Comparing the safety and efficacy of single-port versus multi-port robotic-assisted techniques in urological surgeries: a systematic review and meta-analysis

OBJECTIVE

Comparing the safety and efficacy of single-port (SP) versus multi-port (MP) robotic-assisted techniques in urological surgeries.

METHODS

A systematic review and cumulative meta-analysis was performed using PRISMA criteria for primary outcomes of interest, and quality assessment followed AMSTAR. Four databases were systematically searched: Embase, PubMed, The Cochrane Library, and Web of Science. The search time range is from database creation to December 2022. Stata16 was used for statistical analysis.

RESULTS

There were 17 studies involving 5015 patients. In urological surgeries, single-port robotics had shorter length of stay (WMD = - 0.63, 95% Cl [- 1.06, - 0.21], P < 0.05), less estimated blood loss (WMD = - 19.56, 95% Cl [- 32.21, - 6.91], P < 0.05), less lymph node yields (WMD = - 3.35, 95% Cl [- 5.16, - 1.55], P < 0.05), less postoperative opioid use (WMD = - 5.86, 95% Cl [- 8.83, - 2.88], P < 0.05). There were no statistically significant differences in operative time, positive margins rate, overall complications rate, and major complications rate.

CONCLUSION

Single-port robotics appears to have similar perioperative outcomes to multi-port robotics in urological surgery. In radical prostatectomy, single-port robotics has shown some advantages, but the specific suitability of single-port robots for urological surgical types needs to be further explored.

Advances in lasers for the minimally invasive treatment of upper and lower urinary tract conditions: a systematic review

PURPOSE

Technological advancements in laser lithotripsy are expanding into numerous fields of urology, like ureteroscopy (URS), percutaneous nephrolithotomy (PCNL), and benign and malignant soft-tissue treatments. Since the amount of research regarding lasers in urology has grown exponentially, we present a systematic review of the most recent and relevant advances encompassing all lasers used in urological endoscopic treatment.

METHODS

We performed a literature search using PubMed (May 2023) to obtain information about lasers for urological purposes. We included only recent data from published articles between 2021 and 2023 or articles ahead of print.

RESULTS

Lasers are widely used in lithotripsy for ureteric, renal, and bladder stones, benign prostate surgery, and bladder and upper tract tumor ablation. While the holmium (Ho:YAG) laser is still predominant, there seems to be more emphasis on pulse modulation and newer lasers such as thulium fiber laser (TFL) and pulsed Tm:YAG laser.

CONCLUSION

The use of lasers and related technological innovations have shown increasing versatility, and over time have proven to be invaluable in the management of stone lithotripsy, treatment of benign and malignant prostate diseases, and urothelial tumors. Laser endoscopic treatment is heavily based on technological nuances, and it is essential to know at least the basics of these technologies. Ultimately the choice of laser used depends on its availability, cost, surgeon experience and expertise.

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.

Modern Kidney-Sparing Management of Upper Tract Urothelial Carcinoma

PURPOSE

To review the latest evidence on the modern techniques and outcomes of kidney-sparing surgeries (KSS) in patients with upper tract urothelial carcinoma (UTUC).

METHODS

A comprehensive literature search on the study topic was conducted before 30 April 2023 using electronic databases including PubMed, MEDLINE, and EMBASE. A narrative overview of the literature was then provided based on the extracted data and a qualitative synthesis of the findings.

RESULTS

KSS is recommended for low- as well as select high-risk UTUCs who are not eligible for radical treatments. Endoscopic ablation is a KSS option that is associated with similar oncological outcomes compared with radical treatments while preserving renal function in well-selected patients. The other option in this setting is distal ureterectomy, which has the advantage of providing a definitive pathological stage and grade. Data from retrospective studies support the superiority of this approach over radical treatment with similar oncological outcomes, albeit in select cases. Novel chemoablation agents have also been studied in the past few years, of which mitomycin gel has received FDA approval for use in low-risk UTUCs.

CONCLUSION

KSSs are acceptable approaches for patients with low- and select high-risk UTUCs, which preserve renal function without compromising the oncological outcomes.

Endoscopic Conservative Treatment of Upper Urinary Tract Urothelial Carcinoma with a Thulium Laser: A Systematic Review

INTRODUCTION

Thulium lasers (TLs), namely the Thulium fiber laser (TFL) and the Thulium:YAG (Tm:YAG), are being increasingly adopted for the conservative treatment of upper urinary tract urothelial carcinoma (UTUC). However, to date, the real clinical impact of TLs on UTUC management remains not well-characterized. We performed a review of the literature to summarize the current evidence on TLs for UTUC treatment.

MATERIALS AND METHODS

We performed a systematic review in January 2023 using the Embase and Medline online databases, according to the PRISMA recommendations and using the PICO criteria. Outcomes of interest were: (i) to assess the safety and feasibility of TLs in the treatment of UTUC, and (ii) to evaluate the oncological outcomes in terms of tumor recurrence and conservative treatment failure. Moreover, we described TL characteristics and its interaction with soft tissue.

RESULTS

a total of 458 articles were screened, and six full texts including 273 patients were identified. All the included studies were retrospective series. Mean patient age ranged from 66 to 73 years. The indication of a conservative treatment was elective and imperative in 21.7-85% and 15-76% of cases, respectively. Laser power settings varied from 5 to 50 W. No intraoperative complications were reported, and all the procedures were successfully performed. The tumor recurrence rate was 17.7-44%, and the indication to radical nephroureterectomy was 3.7-44% during a follow-up of 6-50 months. Most of the postoperative complications were mild and transient, and ureteral strictures were reported in two studies. Major limitations were the retrospective nature of the studies, the small sample sizes, and the short follow-up.

CONCLUSIONS

TL is an effective and safe technology for endoscopic UTUC treatment. However, current available literature lacks prospective and multicentric studies with large population sizes and long-term follow-up.

Low- vs. High-Power Laser for Holmium Laser Enucleation of Prostate

Holmium laser enucleation of the prostate (HoLEP) constitutes an established technique for treating patients with symptomatic bladder outlet obstruction. Most surgeons perform surgeries using high-power (HP) settings. Nevertheless, HP laser machines are costly, require high-power sockets, and may be linked with increased postoperative dysuria. Low-power (LP) lasers could overcome these drawbacks without compromising postoperative outcomes. Nevertheless, there is a paucity of data regarding LP laser settings during HoLEP, as most endourologists are hesitant to apply them in their clinical practice. We aimed to provide an up-to-date narrative looking at the impact of LP settings in HoLEP and comparing LP with HP HoLEP. According to current evidence, intra- and post-operative outcomes as well as complication rates are independent of the laser power level. LP HoLEP is feasible, safe, and effective and may improve postoperative irritative and storage symptoms.

Tissue thermal effect during lithotripsy and tissue ablation in endourology: a systematic review of experimental studies comparing Holmium and Thulium lasers

PURPOSE

We looked into the Thulium: yttrium-aluminum-garnet (TM:YAG), Thulium Fibre laser (TFL) and Holmium: yttrium-aluminum-garnet (Ho:YAG) thermal laser tissue effect during lithotripsy and tissue ablation.

METHODS

We performed a PubMed, Scopus, EMBASE, and Cochrane Central Register of Controlled Trials (CENTRAL) search.

RESULTS

During lithotripsy, the Ho:YAG generated temperatures from 24 to 68.7 °C at powers < 20 W, the Tm:YAG from 43.7 °C at 30 W to 68 °C at powers < 20 W, and the TFL from 33 to 40.46 °C. During ablation, the Ho:YAG and continuous wave (cw) Tm:YAG tissue incision depths ranged from 0.08 to 2.26 mm, and from 0.28 to 3.22 mm. The Ho:YAG and Tm:YAG vaporization areas ranged from 0.044 to 0.078 mm² and from 0.050 to 0.078 mm³ and their coagulation zones were 0.075 mm² and 0.125 mm³ respectively. Ho:YAG and Tm:YAG laser damage zones ranged from 0.093 to 2.6 mm³ and from 0.207 to 0.98 mm³ respectively. The TFL incision depth ranged from 0.04 to 5.7 mm. The cw and SuperPulsed (SP) vaporization volumes ranged from 8 to 28.2 mm³/s and from 4 to 11 mm³/s. TFL coagulation depth and coagulation zone ranged from zero to 1.1 mm, 2.2 to 5.1 mm³ in SP mode and from 7.7 to 18.1 mm³ in cw mode.

CONCLUSION

During lithotripsy all lasers caused similar temperature changes and had a safe temperature profile at < 40 W. During tissue ablation, Ho:YAG has a deeper incision depth, while cwTm:YAG and cwTFL have broader coagulation and total laser areas.

Effectiveness and Safety of Thulium Fiber Laser in the Conservative Management of Patients with Upper Tract Urothelial Carcinoma

Background

Few clinical data are available on thulium fiber laser (TFL) and conservative treatment of upper urinary tract urothelial carcinoma (UTUC).

Objective

To assess the effectiveness and safety of TFL in the conservative treatment of UTUC in terms of both tumor ablation and complication rates in a short-term follow-up.

Design setting and participants

Retrospective data were collected from all patients who underwent endoscopic management of UTUC between January 2021 and April 2022. All patients with nonmetastatic UTUC who were deemed suitable candidates (low- and high-grade disease) for conservative treatment were reviewed.

Intervention

All patients underwent ureteroscopy with biopsy and at 2, 6, and 12 mo after the first surgery. UTUC ablation was achieved using TFL.

Outcome measurements and statistical analysis

Clinical data were collected in a dedicated database. Intra- and postoperative outcomes were assessed. A descriptive statistical analysis was performed.

Results and limitations

In total, 28 patients were evaluated. Thirteen patients (46.4%) were included in the low-risk UTUC treatment group and 15 (53.6%) in the high-risk group. The mean tumor size was 15.3 ± 5.7 mm. Biopsy showed low- and high-grade UTUCs in 19 and eight patients, respectively. Only one biopsy was inconclusive for achieving a diagnosis. At the second procedure biopsy, no tumor was found in 19 cases (70.4%), whereas seven had tumors confirmed (25.9%). To date, 23 and 17 out of 26 patients completed the 6- and 12-mo follow-up, respectively. UTUC recurrence was detected in five of 23 patients (21.7%) and in three of 17 patients (17.7%) at 6 and 12 mo, respectively. A total of 95 procedures were performed. No intraoperative complications were observed. In ten of the 95 procedures (10.5%), Clavien-Dindo grade I-II postoperative complications were experienced. Only one grade IIIB postoperative complication was noted.

Conclusions

TFL is a safe and effective technique for conservative treatment of UTUC in a short-term follow-up. Optimal tumor ablation and fine hemostatic control were achieved without major complications.

Patient summary

In this study, we looked at the outcomes of upper urinary tract tumors conservatively treated with the new thulium fiber laser (TFL). We conclude that TFL represents a safe and effective technique for the treatment of this kind of tumors in a short-term follow-up.

Thulium Fiber Laser Behavior on Tissue During Upper- and Lower-Tract Endourology

PURPOSE OF REVIEW

To present the latest evidence on thulium fiber laser (TFL) effects on tissue, during lithotripsy and ablation, emphasizing on generated temperatures, thermal damage thresholds, incision depths, areas of coagulation, and laser damage.

RECENT FINDINGS

Lasers are frequently utilized during endoscopic treatment of different urological conditions. The holmium:yttrium-aluminum-garnet (Ho:YAG) is most frequently used for various types of stones and soft tissue. The TFL has been recently introduced, offering several advantages. However, its activity on tissue during upper and lower tract endourology is poorly understood. At equivalent power settings, TFL and Ho:YAG generate similar temperature changes during lithotripsy. TFL has a shallow incision depth during tissue ablation. Compared to SP TFL, (cw) TFL results in a broader coagulation zone, whereas SP TFL gives of Ho:YAG-similar incision, and (cw) TFL offers a quick, precise cut with more carbonization.

Comparative analysis of MOSESTM technology versus novel thulium fiber laser (TFL) for transurethral enucleation of the prostate: A single-institutional study

INTRODUCTION

Novel laser technologies have been developed for the minimally invasive surgical management of benign prostatic hyperplasia (BPH). The objective of this study was to assess the safety and efficacy of MOSESTM technology versus the thulium fiber laser (TFL) in patients with BPH undergoing transurethral enucleation of the prostate.

METHODS

We conducted a retrospective review of prospectively collected data of eighty-two patients who underwent transurethral enucleation of the prostate using MOSESTM or TFL technologies from August 2020 to September 2021. Preoperative and intraoperative parameters, in addition to postoperative outcomes, were collected and analyzed.

RESULTS

Twenty patients underwent transurethral enucleation of the prostate with TFL, while 62 had MOSESTM HoLEP. No statistically significant difference in preoperative characteristics was observed between the groups. Patients in the TFL group had longer median enucleation, hemostasis, and morcellation times (p < 0.001) than those in the MOSESTM cohort. The longer morcellation time of TFL is mostly related to less visibility. The postoperative outcomes IPSS, QoL, Qmax, and post void residual (PVR), were comparable between the groups at 1, 3 and 6 months. The incidence of urge urinary incontinence (p = 0.79), stress urinary incontinence (p = 0.97), and hospital readmission rates (p = 0.1) were comparable between the two groups.

CONCLUSIONS

A satisfactory safety and efficacy profile with comparable postoperative outcomes was demonstrated for both techniques; though, MOSESTM technology was superior to TFL in terms of shorter overall operative time.