The changing role of lasers in urologic surgery

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).

A 10-year renaissance of en bloc resection of bladder tumors (ERBT): Are we approaching the peak or is it back to the trough?

BACKGROUND

The number of studies suggesting that en bloc resection of bladder tumor (ERBT) is superior to transurethral resection of bladder tumor (TURBT) for non-muscle-invasive bladder cancer (NMIBC) management is growing. The aim of this review is to discuss the features of these procedures and to determine the prospects of en bloc in NMIBC management.

MATERIALS AND METHODS

We conducted a literature search using two databases (Medline and Scopus) and included any research which reported ERBT outcomes.

RESULTS

The lasers with minimal tissue penetration depth are becoming the main tool for ERBT. Unfortunately, most of the systematic reviews continue to be characterized by high heterogeneity. However, recent studies indicate that ERBT may have the edge when it comes to the detrusor muscle rate and the quality of the histological specimen. ERBT may favor in terms of in-field relapse, but its rate in the studies varies greatly. As for out-field relapse-free survival, the data are still lacking. The strongest evidence supports that ERBT is superior to TURBT in complications rate (bladder perforation). ERBT is feasible irrespective to tumor size and location.

CONCLUSIONS

ERBT has gained in momentum with the increasingly widespread use of this kind of laser surgery. The introduction of novel sources (TFL and Thulium:YAG pulsed laser) will definitely affect how the field develops and will result in further improvements in safety and precision. The latest trials make us more certain in our belief that ERBT will be beneficial in terms of histological specimen quality, relapse rate and complications rate.

Comparative study of soft tissue surgery by visible and infrared laser radiation

To compare the cutting properties of lasers with different wavelengths (445 nm, 532 nm and 808 nm) used in cutting blood-rich tissues. Porcine myocardial tissue was cut using 2.3-15 W laser radiation in contact and non-contact modes with an optical fiber or focusing handpiece. The cut depth and coagulation zone width were determined histologically. The 445-nm laser achieved the greatest cut depth for all cutting parameters (p < 0.01). The blue laser gave the smallest coagulation width to cut depth ratio. Results of the study are consistent with the assumption that a 445 nm blue laser may have better cutting properties than green and infrared lasers due to the high absorption of radiation at this wavelength in hemoglobin and, consequently, in the biological blood-rich tissue.

A Review of How Lasers Are Used in UTUC Surgery: Can the Choice of Laser Affect Outcomes?

Upper tract urothelial carcinoma (UTUC) is a relatively rare disease with an aggressive phenotype compared to urothelial carcinoma in the bladder. In recent years, kidney-sparing surgery (KSS) and, in particular, endoscopic surgery have become the procedure of choice among urologists where the treatment of localized UTUC is concerned. Endoscopy tends to result in satisfactory oncological disease control while lowering morbidity and minimizing complications amongst the appropriately selected cohort of patients. While endoscopic surgery for UTUC might appear to be standardized, it, in fact, differs considerably depending on the source of energy used for resection/ablation. There has been little reliable data up to now on which laser energy source is the most superior. The goal of this review is, therefore, to outline the results of endoscopic UTUC treatment using different lasers and to analyze how these laser-tissue interactions may affect the surgery. We start by pointing out that the data remains insufficient when trying to determine which laser is the most effective in the endoscopic management of UTUC. The ever-growing number of indications for minimally invasive treatment and the increasing number of centers using laser surgery will, hopefully, lead to novel randomized controlled trials that compare the performance characteristics of the lasers as well as the effects of UTUC on patients.

Retrospective analysis of 1470-/980-nm dual-wavelength laser en bloc resection versus transurethral resection of bladder tumor for primary non-muscle-invasive bladder cancer

To compare the safety and efficacy of en bloc resection of non-muscle-invasive bladder cancer (NMIBC) using a 1470-/980-nm dual-wavelength laser (DwLRBT) compared to the gold standard, transurethral resection (TURBT). The study group included 251 patients with a confirmed diagnosis of NMIBC, 97 in the DwLRBT group and 154 in the TURBT group. Clinical characteristics, complications, and recurrence-free survival were compared between the two groups. There were no differences between the two groups with regard to age, sex, mean tumor size, mean tumor number, tumor location, risk, fever, and reoperation. Compared to TURBT, DwLRBT was associated with a shorter hospitalization time (mean±standard deviation: 5.81±1.48 days vs. 4.96±1.32, respectively, p=0.001), shorter catheterization time (4.98±1.47 vs. 4.20±1.48 days, respectively; p=0.035), and smaller volume of intraoperative bleeding (8.43±6.21 ml vs. 6.15±5.08, respectively; p=0.003). Recurrence-free survival (RFS) was better for DwLRBT than TURBT in the overall cohort (hazard ratio [HR], 0.4323; 95% confidence interval [CI], 0.2852-0.6554; p=0.0004) and for the following subgroups and tumor types: intermediate-risk (HR, 0.2654; 95%CI, 0.1020-0.6904; p=0.0245) and high-risk (HR, 0.4461; 95% CI, 0.2778-0.7162; p=0.0027) groups; and for pedunculate bladder tumors (HR, 0.4158; 95%CI, 0.2401-0.7202; p=0.0063), single bladder tumors (HR, 0.4136; 95%CI, 0.2376-0.7293; p=0.0072), and multiple bladder tumors (HR, 0.2727; 95%CI, 0.1408-0.5282; p=0.0014). DwLRBT is associated with better operative and postoperative outcomes, including, importantly, a longer RFS, compared to TURBT.

A method for reducing thermal injury during the ureteroscopic holmium laser lithotripsy

Objective

Many studies have demonstrated the heat effect from the holmium laser lithotripsy can cause persistent thermal injury to the ureter. The purpose of this study was to elucidate the use of a modified ureteral catheter with appropriate firing and irrigation to reduce the thermal injury to the "ureter" during the ureteroscopic holmium laser lithotripsy in vitro.

Methods

An in vitro lithotripsy was performed using a modified catheter (5 Fr) as the entrance for the irrigation and the holmium laser fiber while using the remaining space in the ureteroscopic channel as an outlet. Different laser power settings (10 W, 20 W, and 30 W) with various firing times (3 s, 5 s, and 10 s) and rates of irrigation (15 mL/min, 20 mL/min, and 30 mL/min) were applied in the experiment. Temperature changes in the "ureter" were recorded with a thermometer during and after the lithotripsy.

Results

During the lithotripsy, the local highest mean temperature was 60.3 °C and the lowest mean temperature was 26.7 °C. When the power was set to 10 w, the temperature was maintained below 43 °C regardless of laser firing time or irrigation flow. Regardless of the power or firing time selected, the temperature was below 43 °C at the rate of 30 mL/min. There was a significant difference in temperature decrease when continuous 3 s drainage after continuous firing (3 s, 5 s, or 10 s) compared to with not drainage (p<0.05) except for two conditions of 0.5 J×20 Hz, 30 mL/min, firing 5 s, and 1.0 J×10 Hz, 30 mL/min, firing 5 s.

Conclusion

Our modified catheter with timely drainage reducing hot irrigation may significantly reduce the local thermal injury effect, especially along with the special interrupted-time firing setting during the simulated holmium laser procedure.

Laser Efficiency and Laser Safety: Holmium YAG vs. Thulium Fiber Laser

(1) Objective: To support the efficacy and safety of a range of thulium fiber laser (TFL) pre-set parameters for laser lithotripsy: the efficiency is compared against the Holmium:YAG (Ho:YAG) laser in the hands of juniors and experienced urologists using an in vitro ureteral model; the ureteral damage of both lasers is evaluated in an in vivo porcine model. (2) Materials and Methods: Ho:YAG laser technology and TFL technology, with a 200 µm core-diameter laser fibers in an in vitro saline ureteral model were used. Each participant performed 12 laser sessions. Each session included a 3-min lasering of stone phantoms (Begostone) with each laser technology in six different pre-settings retained from the Coloplast TFL Drive user interface pre-settings, for stone dusting: 0.5 J/10 Hz, 0.5 J/20 Hz, 0.7 J/10 Hz, 0.7 J/20 Hz, 1 J/12 Hz and 1 J/20 Hz. Both lasers were also used in three in vivo porcine models, lasering up to 20 W and 12 W in the renal pelvis and the ureter, respectively. Temperature was continuously recorded. After 3 weeks, a second look was done to verify the integrity of the ureters and kidney and an anatomopathological analysis was performed. (3) Results: Regarding laser lithotripsy efficiency, after 3 min of continuous lasering, the overall ablation rate (AR) percentage was 27% greater with the TFL technology (p < 0.0001). The energy per ablated mass [J/mg] was 24% lower when using the TFL (p < 0.0001). While junior urologists performed worse than seniors in all tests, they performed better when using the TFL than Ho:YAG technology (36% more AR and 36% fewer J/mg). In the in vivo porcine model, no urothelial damage was observed for both laser technologies, neither endoscopically during lasering, three weeks later, nor in the pathological test. (4) Conclusions: By using Coloplast TFL Drive GUI pre-set, TFL lithotripsy efficiency is higher than Ho:YAG laser, even in unexperienced hands. Concerning urothelial damage, both laser technologies with low power present no lesions.

The Safety and Efficacy of Vela Laser En-Bloc Endoscopic Resection versus Conventional Transurethral Resection of Bladder Tumor-A Single Center Experience

(1) Background: The current gold standard treatment of bladder cancer is conventional transurethral resection of the bladder tumor (CTURBT) using monopolar or bipolar resectoscopes. Laser en-bloc resection of the bladder tumor (LERBT) could achieve a higher quality of the specimen, reduce perioperative complications, and decrease the recurrence rate. Here, we compare the efficacy and safety of en-bloc Vela laser resection versus the conventional monopolar/bipolar resection; (2) Methods: A total of 100 clinically cT1-2 patients with bladder cancer were retrospectively reviewed in this study. Among these patients, 50 patients received LERBT, and 50 patients received CTURBT. The baseline characteristics, operation variables, and clinical outcomes were collected. The primary performance was the presence of muscle layer in the specimen. Perioperative complications and recurrence-free survival (RFS) were also compared. Independent t-test, Chi-square test, Kaplan–Meier curves, and the Cox-regression model were used in the analysis; (3) Results: The median age of the patients in the laser and resectoscope groups was 69.2 and 68.0 years old, respectively. The statistical difference in the presence of the detrusor muscle was 92.0% in the laser group and 70.0% in the CTURBT group (p = 0.005). A lower incidence of bladder perforation (p = 0.041) and major surgical complications (p = 0.046) in the LEBRT group was observed. We found no differences in operation duration, catheterization time, and hospitalization time after adjustment. Additionally, there was no statistical difference in RFS after a median follow-up time of 25 months; (4) Conclusions: Endoscopic laser en-bloc resection of bladder tumor with Vela laser is an effective method with higher muscle inclusion rate and fewer complications.

Endoscopic laser en bloc removal of bladder tumor. Surgical radicality and improvement of the pathological diagnostic accuracy

INTRODUCTION

Bladder cancer is one of the most common tumors among the general population. The first surgical approach to the tumor is often the transurethral resection with monopolar or bipolar loop. Recently, laser energy has become an alternative for resection of small bladder tumor, because it allows to obtain high quality samples with the "en bloc" technique. Our study aims to show the results of endoscopic diode laser treatment of bladder tumor up to three centimeters in maximum diameter.

MATERIALS AND METHODS

189 patients underwent "en bloc" resection with diode dual length laser (980 nm-1470 nm). Follow up was over 12 months. Patients age range was from 45 to 75 years. Maximum diameter of the lesions was 3.0 cm. For each patient, a cold forceps biopsy sample was performed.

RESULTS

All samples collected presented detrusorial layer. Pathological exam showed: 28 (14.8%) Ta, G1-G2; 7 (3.7%) T3, G2-G3; 14 (7.4%) T1, G2-G3 and 140 ( 74.1%) Ta, G2-G3. No complications occurred during or after surgery. At a median follow-up period of 6 months, we had no recurrence in the previous site of tumor. In the follow up at 3/6/12 months in 4 cases we had recurrence in different sites of bladder wall.

CONCLUSIONS

Laser "en bloc" resection is an effective, feasible, and safe treatment for bladder tumor. It could be a valid alternative to monopolar and bipolar resection in small bladder cancer treatment.

En bloc resection for nonmuscle-invasive bladder cancer: selecting a proper laser

PURPOSE OF REVIEW

To discuss the most recent surgical lasers that have been made available to us and to evaluate their potential in performing en bloc resection of nonmuscle invasive bladder cancer.

RECENT FINDINGS

Laser en bloc resection of bladder tumors (ERBT) can be performed with a number of laser systems including Ho:YAG, GreenLight, diode, Tm:YAG and thulium fiber lasers (TFL). The data that is currently available suggests that the water-targeting devices (utilizing water as a primary chromophore - Ho:YAG, Tm:YAG, TFL) may have a number of advantages over hemoglobin-targeting systems (potassium titanyl phosphate:YAG, lithium triborate:YAG). One recent addition to the surgical armamentarium Moses effect enhanced Ho:YAG and the TFL (being able to work both in quasi-continuous and SuperPulsed modes) necessitates careful discussion and comparison with the other available devices.

SUMMARY

The majority of available lasers have proven to be safe to use and compared to electrocautery allow for lower rates of obturator nerve reflex and result in fewer bleeding complications. The minimal penetration depth and decreased peak power of Tm:YAG and TFLs render them the devices of choice when it comes to ERBT. Unfortunately, more studies on ERBT with TFL are needed in order for us to make a sound assessment of the respective pros and cons.

Current evidence for focal laser ablation and vascular-targeted photodynamic therapy for localized prostate cancer: review of literature published in the last 2 years

PURPOSE OF REVIEW

Currently, a significant number of patients are diagnosed with unilateral and apparently unifocal low or intermediate-risk prostate cancer (PCa). These patients are suitable for focal therapy, thus preventing radical treatment side effects without affecting cancer control. Among focal therapy energy sources, laser-based technologies have shown promising outcomes. We aimed to summarize recent data on focal laser ablation (FLA) and vascular-targeted photodynamic therapy (VTP) for PCa.

RECENT FINDINGS

We selected eight studies reporting data on 1155 patients with PCa who underwent laser-based focal therapy. Five studies were on FLA and three on VTP (six prospective and two retrospective series); four reported both oncologic and functional outcomes whereas in three only oncologic and one only functional outcomes were discussed. Follow-up protocols and durations varied widely among the studies. PCa recurrence rates ranged between 20 and 56%. Urinary and erectile function were preserved after treatment, and complications were mild and transient. A lack of high-quality data on long-term oncological outcomes still remains, thus further highlighting the need for prospective controlled studies.

SUMMARY

FLA and VTP are well tolerated procedures with excellent functional outcomes. However, both procedures showed a significant rate of PCa recurrence, thus demonstrating a certain grade of oncologic control failure of the procedure and/or nonoptimal patients' selection.

Retrograde intrarenal surgery: laser showdown (Ho:YAG vs thulium fiber laser)

PURPOSE OF REVIEW

Retrograde intrarenal surgery (RIRS) has always been recommended for large stones > 20 mm, using the Ho:YAG laser. The introduction of a new technology in the urological market, the thulium fiber laser (TFL) has revolutionized the endourology world because of its characteristics and significantly shorter laser-on time (LOT) and operative time, without scarifying the champ vision. The aim of this review is to evaluate the most relevant findings of the last 2 years of each laser technology, confronting Ho:YAG vs TFL, analyzing who is more suitable for performing an efficient RIRS.

RECENT FINDINGS

Five full clinical trials using TFL for RIRS were found. Median LOT was between 2.8 and 34 min. All stones were similar in terms of stone volume, >500 mm3, and stone density, > 800 HU. Low complication rate, mostly Clavien-Dindo grade I and II and not related to the laser itself. One clinical trial only analyzed the efficacy of TFL for > 20 mm renal stones.

SUMMARY

Based on this review, TFL performs a more efficient RIRS than the Ho:YAG laser with similar safety.

Thulium fiber laser in urology: physics made simple

PURPOSE OF REVIEW

In this narrative review, we will focus on a novel thulium fiber laser's physical properties in terms of its clinical applicability.

RECENT FINDINGS

TFL has successfully moved forward from the preclinical trials into clinical practice and now is being widely used in clinics around the world. The available data suggest that the device effectively operates in soft tissues - benign prostate hyperplasia (BPH) and bladder tumors, as well as in lithotripsy. Also, the first promising results were obtained from laparoscopic surgery showing its possible applicability in the management of renal cell carcinoma. The constructional changes in fiber laser's design, lead to alteration of laser-tissue interactions, which resulted in clinical advantages of the device. Yet, the exact mechanism often is considered complex for understanding. With this work, we are aiming to build a bridge between biophysics and clinical practice and give a simple explanation of how the devices is working and why the knowledge of it is important for a clinician.

SUMMARY

The more effective wavelength (closer to the water absorption peak), favorable beam profile, different modes of action allowing to decrease carbonization on one hand and retropulsion on the other, all this makes TFL an evolution in urologic surgery. Further trials investigating on the possible pros and cons of the device are awaited.

Comparative efficacy and safety of transurethral laser surgery with holmium laser, KTP laser, 2-micron laser or thulium laser for the treatment of non-muscle invasive bladder carcinoma: a protocol of network meta-analysis

INTRODUCTION

The potential of transurethral laser surgery in treating non-muscle invasive bladder cancer (NMIBC) has been confirmed, however which types of lasers may be preferentially prescribed remains a debate. The aim of this network meta-analysis is to investigate the comparative efficacy and safety of transurethral laser surgery with four common types of laser including holmium laser, potassium titanylphosphate (KTP) laser, 2-micron laser or thulium laser for the treatment of NMIBC.

METHODS AND ANALYSIS

A systematic search will be conducted to search all potentially eligible randomised controlled trials comparing different transurethral laser surgeries with each other or with standard transurethral resection among patients with NMIBC in PubMed, Embase, the Cochrane library, China National Knowledge Infrastructure, Wanfang database and Chongqing VIP from their inception until 31 May 2021. Two reviewers will be asked to independently select eligible studies, and assess the risk of bias of individual study with Cochrane risk of bias assessment tool. A random-effects network meta-analysis based on Markov chain Monte Carlo method will be carried out. Ranking probabilities will be considered to rank all laser types. Quantitative analysis will be carried out by using WinBUGS V.1.4.3.

ETHICS AND DISSEMINATION

Ethical approval is not required because this is a network meta-analysis of published data. We will submit all findings to some conferences for preliminary communication and to a peer-reviewed journal for publication.

TRIAL REGISTRATION NUMBER

10.17605/OSF.IO/TD9MW.

New Lasers for Stone Treatment

Laser technology has been a breakthrough in urology. The new era in endocorporeal laser lithotripsy has recently begun in mid-2020, where promising technologies tested in vitro have reached their approval for clinical use and, in that way, have made it possible to confirm their safety and advantages in the real world, for the patient and for the urologist.

Laser endoscopic procedures on the prostate: it is the small details that count

PURPOSE OF REVIEW

This review aims to highlight the pros and cons of each laser device and to consider additional possible milestones for the development of laser technologies in the surgical treatment of benign prostate hyperplasia.

RECENT FINDINGS

Over the last three decades, lasers' role in endourology has gone from strength to strength. Specifically, the primary techniques where laser surgery for BPO relief is concerned are vaporization and enucleation. The idea behind vaporization is that lasers are able to vaporize substantial amounts of tissue due to deep ablation depth and increased power. The most efficient devices for vaporization are those affecting hemoglobin as primary chromophore and/or using a continuous firing mode (KTP/LBO:YAG, diode lasers, Tm:YAG). As for enucleation, multiple devices have been suggested for the adequate anatomical enucleation of the prostate (EEP). As it is a skill-dependent technique, the EEP is effective irrespective of which device the surgeon uses. However, some devices have shown significant advances where enucleation is concerned.

SUMMARY

The choice of device should be based primarily on the technique the surgeon prefers. Although the most suitable lasers for vaporization are hemoglobin-targeting and/or continuous wave devices, the EEP may be done with any enough powered laser, yet some provides specific effects which you should be aware before the surgery.

Superpulse thulium fiber laser lithotripsy: an in vitro comparison of 200 μm and 150 μm laser fibers

PURPOSE

To investigate the thermal effects, stone retropulsion and ablation rate of SuperPulse Thulium-fiber laser (SP TFL) with two different surgical fibers of 200 and 150 μm in diameter.

METHODS

SP TFL (NTO IRE-Polus, Fryazino, Russia) performance with 200 and 150 μm fibers (NTO IRE-Polus, Fryazino, Russia) was evaluated. Before each test, the laser fiber was cleaved, and the power measurement was taken to verify the actual laser output power. To compare the laser fibers in well-controlled environments, a number of setups were used to assess retropulsion, ablation efficacy, fiber burnback, energy transmission, and safety.

RESULTS

Power measurements performed before each test revealed a 4.7% power drop for a 200 μm fiber SP TFL (14.3 ± 0.5 W) and 7.3% power drop for a 150 μm fiber SP TFL (13.9 ± 0.5 W) versus the nominally indicated power (15.0 W). Retropulsion with the TFL was minimal and comparable between fibers. We found no clinically relevant temperature differences between SP TFL with either 200 or 150 μm fibers. The ablation efficacy tended to be comparable under most parameters. Yet, we did observe a decreased diameter of residual fragments after the ablation with a 150 μm fiber.

CONCLUSION

The smaller fiber (150 μm) is not inferior to 200 μm fiber in terms of fiber burnback, retropulsion, safety, and ablation rate. Moreover, it has the potential to decrease the diameter of fragments during lithotripsy, which may facilitate dusting during RIRS.

A review of thulium-fiber laser in stone lithotripsy and soft tissue surgery

PURPOSE OF REVIEW

To evaluate emerging evidence and practical applications of thulium-fiber laser (TFL) for genitourinary soft tissue disease and urinary stone disease treatment.

RECENT FINDINGS

A systematic review was developed using the PubMed, ScienceDirect, Wiley, SpringerLink and Mary Ann Liebert Scopus databases between 2012 and 2020 years, using the PRISMA statement. We analyzed recent publications including in vitro and in humans outcomes of surgery using TFL. This new laser technology can be used in soft tissue diseases and stones present in the genitourinary system. Most of the comparisons are made with the Ho:YAG laser, using completely different settings. Nevertheless, TFL is safe, feasible and effective in the management of urologic diseases, showing superiority to Ho:YAG even in some studies.

SUMMARY

The introduction of pulsed TFL technology has enabled the ablation of stones at rates comparable to or better than currently existing lasers in vitro, while also potentially reducing stone retropulsion. TFL is effective in treating genitourinary soft tissue diseases, including benign prostatic hyperplasia, and early data indicate that it may be effective in the treatment of urinary stone disease. More clinical studies are needed to better understand the indications for this novel technology and clarify its position in the urologic endoscopy armamentarium.

Alternative Management of a Pediatric Case of Hemorrhagic Cystitis due to BK Virus: Use of Thulium Laser Coagulation

We report on a pediatric case of hemorrhagic cystitis due to BK virus in a patient with acute lymphoblastic leukemia who had undergone bone marrow transplantation. A very large hematoma that almost completely filled the bladder was aspirated using a morcellator via suprapubic percutaneous access, and a thulium laser was then used to cauterize extensive areas of diffuse uroepithelial bleeding. This combined minimally invasive procedure was successful in clearing the bladder hematoma and achieving hemostasis.

Overnight Continuous Saline Bladder Irrigation After En Bloc Resection of Bladder Tumor Does Not Improve Oncological Outcomes in Patients Who Have Received Intravesical Chemotherapy

Objective

To evaluate the safety and efficacy of overnight continuous saline bladder irrigation (CSBI) for patients who have received thulium laser en bloc resection of bladder tumor (TmLRBT) combined with immediate intravesical chemotherapy previously.

Methods

From October 2014 to June 2018, 235 patients with newly diagnosed non-muscle invasive bladder cancer (NMIBC) were included in this retrospective study. All patients received intravesical instillation of pirarubicin immediately after TmLRBT. The patients were divided into two groups according to the duration of postoperative bladder irrigation with normal saline. After immediate intravesical chemotherapy, patients in group 1 received overnight CSBI, while patients in group 2 did not receive overnight CSBI. Data on the time of initial tumor recurrence, recurrence-free survival (RFS) and progression-free survival (PFS) rates, and perioperative complications were collected and analyzed.

Results

Of 235 included patients (129 in group 1 and 106 in group 2), the median follow-up periods were 42 and 38 months, respectively. There were no significant differences in patients' baseline characteristics between the two groups. The RFS rates of patients in group 1 were 90.7, 82.7, and 76.8% at the end of the first, third, and fifth years, while the corresponding RFS rates of patients in group 2 were 87.7, 78.9, and 73.3%, respectively. Four patients in group 1 and five patients in group 2 experienced tumor progression. No significant differences between the two groups were observed in the time of initial tumor recurrence, RFS, and PFS rates. Only Grade I complications occurred in the two groups, and no significant difference was reached between the two groups.

Conclusions

For patients with NMIBC who have previously received TmLRBT combined with immediate intravesical chemotherapy, overnight CSBI may not improve oncological outcomes and reduce perioperative complications.

Minimally invasive percutaneous nephrolithotomy with SuperPulsed Thulium-fiber laser

We aimed to assess the efficacy and safety of minimally invasive percutaneous nephrolithotomy (PCNL) with SuperPulsed Thulium-fiber laser (SP TFL) using different frequency settings. 125 patients with solitary kidney calculi of up to 55 mm in the maximum diameter underwent mini-PCNL with the SP TFL. Stone-free rate, laser-on time, ablation efficacy, energy consumption, ablation speed and complications were all analyzed. Negative low-dose computed tomography scan or asymptomatic patients with stone fragments < 2 mm were the criteria for assessing the stone-free status. In 36 patients (28.8%) low frequency regimens were used (LF: 3-19 Hz-0.5-6 J), in 75 patients (60%) high frequency regimens were chosen (HF: 20-49 Hz-0.2-2 J) and in 14 (11.2%) patients higher frequency (HRF: 50-200 Hz-0.1-0.5 J) regimens were preferred. The mean age was 52 ± 1.8 years. Median stone diameter and median stone volume were larger at low frequency regimens compared to high frequency regimens. Ablation efficacy (J/mm³) was lower at low rather than at high frequency regimens. Ablation speed (mm³/sec) was higher at low compared to high frequency regimens. Surgeons reported minimal and absent retropulsion at higher frequency regimens. The best visibility was observed at high frequency regimens. The overall stone free rate (SFR) at 3 months was 85%. The majority of the postoperative complications were classified between Clavien grades I-II. SP TFL is an effective and safe tool for performing mini-PCNL regardless of the laser settings.

Outcomes of thulium fibre laser for treatment of urinary tract stones: results of a systematic review

PURPOSE OF REVIEW

Lasers have become a fundamental aspect of stone treatment. Although Holmium:Yttrium-Aluminum-garnet (Ho:YAG) laser is the current gold-standard in endoscopic laser lithotripsy, there is a lot of buzz around the new thulium fibre laser (TFL). We decided to evaluate the latest data to help create an objective and evidence-based opinion about this new technology and associated clinical outcomes.

RECENT FINDINGS

Sixty full-text articles and peer-reviewed abstract presentations were included in the qualitative synthesis of this systematic review performed over the last 2 years. Current super pulsed TFL machines are capable of achieving peak powers of 500W and emit very small pulse energies of 0.025 Joules going up to 6 Joules, and capable of frequency over 2000 Hz. This makes the TFL ablate twice as fast for fragmentation, 4 times as fast for dusting, more stone dust of finer size and less retropulsion compared to the Ho:YAG laser. Because of the smaller laser fibres with the TFL, future miniaturization of instruments is also possible.

SUMMARY

Based on the review, the TFL is a potential game-changer for kidney stone disease and has a promising role in the future. However larger multicentric prospective clinical studies with long-term follow-up are needed to establish the safety and efficacy of the TFL in endourology.

Endoscopic lithotripsy with a SuperPulsed thulium-fiber laser for ureteral stones: A single-center experience

OBJECTIVES

To estimate the efficacy and safety of SuperPulsed thulium-fiber laser ureteral lithotripsy and to identify optimal laser settings.

METHODS

Patients with solitary stones were prospectively included. Lithotripsy was performed with a SuperPulsed thulium-fiber laser (NTO IRE-Polus, Fryazino, Russia) using a rigid ureteroscope 7.5 Ch (Richard Wolf, Knittlingen, Germany). We analyzed the efficacy of lithotripsy by measuring total energy required for stone disintegration, "laser-on" time, ablation speed, ablation efficacy, and energy consumption. Stone retropulsion and visibility were assessed using a three-point Likert scale. Complications were assessed using the Clavien-Dindo classification system.

RESULTS

A total of 149 patients were included. The mean stone density was 985 ± 360 Hounsfield units, the median (interquartile range) stone volume was 179 (94-357) mm3 . The median (interquartile range) total energy was 1 (0.4-2) kJ, and laser-on time 1.2 (0.5-2.7) min. The median (interquartile range) stone ablation speed was 140 (80-279) mm3 /min, energy for ablation of 1 mm3 was 5.6 (3-9.9) J/mm3 and energy consumption was 0.9 (0.6-1) J/min. A correlation was found between retropulsion and the energy used (r = 0.5, P < 0.001). Multivariable analysis showed energy to be a predictor of increased retropulsion (odds ratio 65.7, 95% confidence interval 1.6-2774.1; P = 0.028). No predictors for worse visibility were identified.

CONCLUSION

The SuperPulsed thulium-fiber laser provides effective and safe lithotripsy during ureteroscopy regardless of stone density. Fiber diameter and laser frequency do not influence visibility or safety. Optimal laser settings are 0.5 J × 30 Hz for fragmentation and 0.15 J × 100 Hz for dusting.

A scoping review of the clinical efficacy and safety of the novel thulium fiber laser: The rising star of laser lithotripsy

INTRODUCTION

The holmium:yttrium-aluminum-garnet (Ho:YAG) laser is the gold standard for intracorporeal lithotripsy. Preclinical reports suggest the thulium laser fibre (TFL) may possess advantages over the Ho:YAG laser, including improved lithotripsy efficacy, enhanced safety, and lower costs. Although the TFL is well-characterized in-vitro, there are no reviews examining TFL lithotripsy in a clinical setting.

METHODS

A review of the literature was conducted using a systematic search of MEDLINE, PubMed, and Embase, yielding a total of 130 manuscripts published up to May 2020. Two independent reviewers selected studies for screening, eligibility, and inclusion into the scoping review. Following the title, abstract, and full-text review, 14 articles were analyzed.

RESULTS

Within these articles, there were 13 prospective cohort studies and one case series. The average sample size was 100 participants. Study followup durations ranged from four weeks to three months. TFL had comparable stone-free rates to Ho:YAG lasers and improved operating time. TFL was subjectively favorable in terms of stone retropulsion, stone fragmentation, endoscopic maneuverability, and endoscopic visibility. TFL appeared clinically safe and did not result in any major complications. Many studies were underpowered and non-peer-reviewed, demonstrating the need for additional research in this field.

CONCLUSIONS

The TFL has the potential to catalyze a paradigm shift in laser lithotripsy. While the objective of this scoping review was to describe the contemporary landscape of the literature, it is important to consider that inferences posed by the studies described herein must be tempered by the low quality of available evidence.

Ex vivo study of Ho:YAG and thulium fiber lasers for soft tissue surgery: which laser for which case?

The goal of this study was to assess the ablation, coagulation, and carbonization characteristics of the holmium:YAG (Ho:YAG) laser and thulium fiber lasers (TFL). The Ho:YAG laser (100 W av.power), the quasi-continuous (QCW) TFL (120 W av.power), and the SuperPulsed (SP) TFL (50 W av.power) were compared on a non-frozen porcine kidney. To control the cutting speed (2 or 5 mm/s), an XY translation stage was used. The Ho:YAG was tested using E = 1.5 J and P_av = 40 W or P_av = 70 W settings. The TFL was tested using E = 1.5 J and P_av = 30 W or P_av = 60 W settings. After ex vivo incision, histological analysis was performed in order to estimate thermal damage. At 40 W, the Ho:YAG displayed a shallower cutting at 2 and 5 mm/s (1.1 ± 0.2 mm and 0.5 ± 0.2 mm, respectively) with virtually zero coagulation. While at 70 W, the minimal coagulation depth measured 0.1 ± 0.1 mm. The incisions demonstrated zero carbonization. Both the QCW and SP TFL did show effective cutting at all speeds (2.1 ± 0.2 mm and 1.3 ± 0.2 mm, respectively, at 30 W) with prominent coagulation (0.6 ± 0.1 mm and 0.4 ± 0.1 mm, respectively, at 70 W) and carbonization. Our study introduced the TFL as a novel efficient alternative for soft tissue surgery to the Ho:YAG laser. The SP TFL offers a Ho:YAG-like incision, while QCW TFL allows for fast, deep, and precise cutting with increased carbonization.

Systematic review of the endoscopic enucleation of the prostate learning curve

INTRODUCTION

It has been shown that endoscopic enucleation of the prostate (EEP) allows for similar efficacy and safety, no matter what energy and type of instruments we use, but the length of learning may differ greatly. The aim of this systematic review is to verify if there is any significant difference between EEP methods in learning.

EVIDENCE ACQUISITION

We performed a systematic literature search in three databases and included only the articles containing their own data on the EEP learning curve assessment during the last 10 years. The primary endpoint was to determine the necessary experience needed to achieve a plateau. The secondary endpoints were to review methods used to evaluate a learning curve.

EVIDENCE SYNTHESIS

The final sample included 17 articles, containing a total of 4615 EEPs performed by 76 surgeons, the most common method was HoLEP (9/17). The majority of articles studying HoLEP report a learning curve of experience level achievement in roughly 30-40 (min 20; max 60) cases. The studies of GreenLight laser showed high heterogeneity in the results with minimum of 20 cases and maximum of 150-200 cases. TUEB required roughly 40-50 cases to reach the plateau.

CONCLUSION

Although EEP is considered challenging, it shows a steep learning curve with a plateau after 30-50 cases. Proper criteria are critical for accurate assessment of the learning curve. The Trifecta and Pentafecta criteria are currently the most appropriate method to evaluate EEP learning.

Superpulsed Thulium Fiber Laser for Stone Dusting: In Search of a Perfect Ablation Regimen-A Prospective Single-Center Study

Objective: To compare the efficacy of the standard and higher frequency regimens for superpulsed thulium fiber laser (SP TFL) retrograde intrarenal surgery (RIRS). Materials and Methods: A prospective study of patients with renal calculi of 10-30 mm was performed. For RIRS, we used the SP TFL (NTO IRE-Polus, Russia) and a 9.5F flexible ureteroscope with 270° deflection and 3.6F working channel. Retropulsion and visibility were assessed based on the surgeon's feedback using three-point Likert scales. The stone-free rate was assessed at 3 months with CT. Results: A total of 40 patients were included in the study with a mean age of 56 years, mean stone density of 880 ± 381 HU, mean stone size of 16.5 ± 6.8 mm, and median stone volume of 883 (interquartile range 606-1664) mm³. Both ablation efficacy and speed were higher in the 200-Hz mode (2.7 J/mm³ vs 3.8 J/mm³ and 5.5 mm³/second vs 8.0 mm³/second, respectively); moreover, the higher frequency correlated with increased ablation speed (r = -0.21, p = 0.019). However, both increased energy and frequency did not lead to increase of laser-on time or intraoperative complication rates. Conclusions: SP TFL is able to effectively disintegrate stones during RIRS with minimal complication rates. The use of higher frequency regimens showed higher efficacy and ablation speed and was not associated with increased complication rates.

Efficacy and Safety of Transurethral Laser Surgery Versus Transurethral Resection for Non-Muscle-Invasive Bladder Cancer: A Meta-Analysis and Systematic Review

OBJECTIVE

To compare the efficacy and safety of transurethral laser surgery and transurethral resection of a bladder tumor (TURBT) for non-muscle-invasive bladder cancer (NMIBC).

MATERIAL AND METHODS

A research was carried out in Medline via PubMed, EMBASE, the Cochrane Library, and Web of Science up to October 20, 2019, to identify articles related to transurethral laser surgery and TURBT for NMIBC. All analyses were done using RevMan5.3 and Stata14.

RESULTS

A total of 17 studies involving 2,439 participants were included. The analysis showed no significant difference in operation times (mean difference = -0.2; 95% CI -2.29 to 1.89; p = 0.85) or occurrences of urethral stricture (OR = 0.7; 95% CI 0.24-2.06; p = 0.52). Transurethral laser surgery was associated with a lower incidence of obturator nerve reflex (OR = 0.04; 95% CI 0.02-0.09; p < 0.00001) and bladder perforation (OR = 0.09; 95% CI 0.04-0.23; p < 0.00001), a higher rate of detrusor muscle acquisition (OR = 5.28; 95% CI 2.42-11.49; p < 0.0001), shorter catheterization (mean difference = -1.05; 95% CI -1.41 to -0.68; p < 0.00001) and hospitalization times (mean difference = -0.96; 95% CI -1.59 to -0.33; p = 0.003), and lower rates of bladder irrigation (OR = 0.21; 95% CI 0.13-0.35; p < 0.00001) and recurrence both at 12 months (OR = 0.66; 95% CI 0.48-0.9, p = 0.008) and at 24 months (OR = 0.6; 95% CI 0.41-0.86; p = 0.005).

CONCLUSIONS

Transurethral laser surgery for NMIBC, as compared to TURBT, is associated with a lower incidence of complications, a lower recurrence rate, and faster postoperative recovery.

Thulium-fiber laser for lithotripsy: first clinical experience in percutaneous nephrolithotomy

PURPOSE

To evaluate the efficacy and safety of thulium-fiber laser (TFL) in laser lithotripsy during percutaneous nephrolithotomy (PCNL).

METHODS

Patients with stones < 30 mm were prospectively recruited to undergo PCNL using TFL "FiberLase" (NTO IRE-Polus, Russia). Stone size, stone density, operative time, and "laser on" time (LOT) were recorded. Study included only cases managed with fragmentation. Stone-free rate and residual fragments were determined on postoperative computer tomography. Complications were classified using the Clavien-Dindo grade. Stone retropulsion and endoscopic visibility were assessed based on surgeons' feedback using a questionnaire.

RESULTS

A total of 120 patients were included in the study with a mean age of 52 (± 1.8) years; of these 77 (56%) were males. Mean stone size was 12.5 (± 8.8) mm with a mean density of 1019 (± 375) HU. Mean operative time was 23.4 (± 17.9) min and mean LOT was 5.0 (± 5.7) min. Most used settings were of 0.8 J/25-30 W/31-38 Hz (fragmentation). The mean total energy for stone ablation was 3.6 (± 4.3) kJ. Overall stone-free rate was 85%. The overall complication rate was 17%. Surgeons reported stone retropulsion that interfered with surgery in 2 (1.7%) cases insignificant retropulsion was noted in 16 (10.8%) cases. Poor visualization was reported in three (2.5%) cases and minor difficulties with visibility in four (3.3%) cases.

CONCLUSIONS

TFL is a safe and effective modality for lithotripsy during PCNL and results in minimal retropulsion.