High-Power Holmium Laser Research Articles

A1187 - Evaluation of relationship with temperature and laser tip distance in high-power holmium laser use by measurement of thermography and thermometer: Ex-vivo phantom study

A1187 - Evaluation of relationship with temperature and laser tip distance in high-power holmium laser use by measurement of thermography and thermometer: Ex-vivo phantom study

A0875 - Energy density in high-power (100w) holmium laser enucleation of the prostate (holep) -retrospective analysis of procedural, and functional outcomes among 1,515 patients

A0875 - Energy density in high-power (100w) holmium laser enucleation of the prostate (holep) -retrospective analysis of procedural, and functional outcomes among 1,515 patients

Role of low- versus high-power laser in the treatment of lower pole stones: prospective non-randomized outcomes from a university teaching hospital.

Introduction:Ureteroscopy and laser stone fragmentation [flexible ureteroscopy and laser lithotripsy (FURSL)] has risen over the last two decades. Laser technology has also evolved over the time, shifting from low- to high-power lasers with the addition of MOSES technology that allows for ‘dusting and pop-dusting’ of stones. The aim of the study was to look at the outcomes of FURSL in lower pole stones (LPS) using low- and high-power lasers.Patient and Methods:In this study, we compared the outcomes of low-power holmium laser (group A, 20 W) and high-power holmium laser (group B, including both 60 W MOSES integrated system and 100 W lasers) for all patients with LPS treated with laser lithotripsy. Data were collected for patient demographics, stone location, size, pre- and postoperative stent, length of stay, complications and stone free rate (SFR).Results:A total of 284 patients who underwent FURSL procedure for LPS were analysed (168 group A, 116 group B). Outcomes showed that compared with group A, group B had a higher SFR (91.6% versus 96.5%, p = 0.13) and shorter operative time (52 versus 38 min, p < 0.001). The median length of stay was <24 h in all groups (day-case procedures). The complication rate was comparable between the two groups but with more infectious complications (n = 7) noted in group A compared with group B (n = 3) (p = 0.53).Conclusion:Compared with low-power laser, the use of high-power laser for LPS significantly reduced the use of ureteral access sheath (UAS), postoperative stent and procedural time. Although non-statistically significant, the SFR was higher in the high-power group even for relatively larger stone sizes, which was also reflected in a reduction of sepsis-related complication rates with these lasers.

Size Distribution of Fragments by High-power Holmium Laser Lithotripsy in MiniPCNL with Suction.

Data are lacking on distribution of size of fragments created with the laser lithotripsy, stone density, and composition. Dust (< 1mm) and small fragments (1-3mm) may be too small to be efficiently removed with forceps compared to larger fragments (> 3mm). We aim to report the size distribution of fragments formed during holmium laser lithotripsy. One hundred ten patients with renal calculi < 3cm underwent miniPCNL using ClearPetra sheath (Well Lead Medical Co., China) with controllable irrigation and suction system that minimizes fragment dispersion and maximizes fragment aspiration. Moses holmium laser (Lumenis INC, Israel) was used with predefined laser energy settings for lithotripsy. Proportion of fragment size < 1mm was 46.36 ± 16.68%, 1-3mm was 28.18 ± 10.01%, and > 3mm was 25.19 ± 16.18% for the entire cohort. Complete stone clearance at 48h was achieved in 77.3% cases. The remaining 22.7% patients had complete clearance at 1-month follow-up CT. In all the stone density, volume, and composition groups, majority of fragments created were either < 1mm or 1-3mm. Only 25% fragments were > 3mm that would get aspirated out through the sheath with suction or could be retrieved with forceps. The combination of a high-power holmium laser and suction would help in complete stone clearance with effective aspiration of smaller stone fragments and dust simultaneously during lasing.

Safety and Efficacy of High-Powered Holmium Laser Enucleation of the Prostate within 1–3 Weeks Following Prostate Biopsy

Purpose: We aim to document the feasibility, perioperative safety, and the 12-month efficacy of holmium laser enucleation of the prostate (HoLEP) within 1–3 weeks following transrectal ultrasound (TRUS)-guided prostate biopsy. Methods: Data of the patients who underwent HoLEP following TRUS-guided prostate biopsy between March 2017 and July 2020 were analyzed retrospectively. Patients were divided into 2 groups: group 1 had undergone HoLEP in the early period after TRUS-guided prostate biopsy, while group 2 patients were biopsy-naive (“control group”). All patients were assessed preoperatively by a physical examination with the digital rectal examination; time from biopsy to HoLEP; measurement of Qmax, postvoiding residual volume, and prostate volume by transabdominal ultrasonography; serum prostate-specific antigen level, the International Prostate Symptom Score (IPSS); the International Index of Erectile Function-5 questionnaire; and urine analysis. The patients were reevaluated at 3- and 12-month follow-up. Perioperative and postoperative complications were documented according to the modified Clavien-Dindo System. Results: Group 1 comprised 66 patients with a mean age of 67.3 ± 6.7 (range, 53–86) years, and group 2 comprised 114 patients with a mean age of 69.4 ± 9.4 (range, 36–95) years. The operation, enucleation, and morcellation efficiencies were not statistically significant between the groups. Preoperative Qmax and IPSS values were significantly improved after HoLEP surgery in the 3rd and 12th months in all patients. Our complication rates were similar in both groups. Conclusion: High-powered HoLEP using 140 W energy within 1–3 weeks following TRUS-guided prostate biopsy is a feasible procedure with high enucleation efficiency, low perioperative morbidity, and excellent functional outcomes. A recent TRUS-guided prostate biopsy is not a contraindication to HoLEP.

Watt matters: Safety and efficacy of using a 140-W high-powered holmium laser for enucleation of the prostate (HoLEP).

This study aimed to assess the perioperative and the 12-month efficacy and safety of 140 W high-powered holmium laser for enucleation of the prostate (HP-HoLEP) for the treatment of benign prostatic obstruction. The data of 540 patients who underwent HoLEP by a single surgeon were analyzed retrospectively. Preoperative evaluation included a physical examination with a digital rectal examination, measurement of maximum urinary flow rate (Qmax), postvoid residual volume (PVR) and prostate volume by transabdominal ultrasonography, serum prostate-specific antigen (PSA), international prostate symptom score (I-PSS) and international index of erectile function-5 (IIEF-5) questionnaires, and urine analysis. Morcellation, enucleation, and operation efficiencies were calculated with the resected weight divided by morcellation, enucleation, and operative times, respectively. The patients were reassessed at 1, 3, 6, and 12 months after surgery by I-PSS, IIEF-5, Qmax, PSA, and the occurrence of complications. The mean operative time was 65.2±20.9 minutes. The mean enucleation time and efficiency were 53±15.1 minutes and 1.72±0.4 g/min, respectively. The mean morcellation time and efficiency were 12.3±15.1 minutes and 7.4±3.2 g/min respectively. Clavien grade 1 complications were observed in 102 (18.9%) patients, Clavien grade 2 complications in 20 (3.7%) patients, and Clavien grade 3b complications in 23 (5.4%) patients. I-PSS, Qmax, and IIEF-5 at postoperative 1, 3, 6, and 12 months were significantly better than baseline results. Our study demonstrated that 140 W HP-HoLEP can be performed with high enucleation efficiency, low perioperative and postoperative complication rates, and excellent functional results.

Clinical Comparison of Super Pulse Thulium Fiber Laser and High-Power Holmium Laser for Ureteral Stone Management.

Purpose: To evaluate the efficacy of new super pulse thulium fiber laser (SP TFL) and compare it with holmium laser for ureterolithotripsy. Patients and Methods: A total of 174 patients with solitary ureteral calculi were enrolled in 2016 to 2018. Stone sizes ranged between 0.6 and 2.4 cm. The SP TFL FiberLase U2 and 120H Ho:YAG laser with fibers diameters of 400 and 365 μm, respectively, were used. The laser settings were 1 J × 10 Hz = 10 W for both devices. All patients were randomized into two groups. The age, stone size, location, and density were comparable in both groups. The evaluated parameters were operation time, endoscopic view quality, retropulsion grade, stone-free rate, and complication rate. Results: The total operation time and lasering time were longer in the Ho:YAG group (24.7 ± 0.7 minutes vs 32.4 ± 0.7 minutes, p = 0.05), and postoperative stenting was necessary in one vs four cases, respectively. At 30 days of follow-up, no residual stones were observed in the SP TFL group (vs five cases of Ho:YAG). Conclusion: SP TFL technology was associated with excellent efficacy/safety ratio. The SP TFL may be considered as a viable alternative to Ho:YAG laser stone management.

Burnback: the role of pulse duration and energy on fiber-tip degradation during high-power laser lithotripsy.

High-power holmium lasers have become popular for ureteroscopic laser lithotripsy and dusting. Our aim was to investigate the effect of pulse duration and pulse energy on fiber-tip degradation when using high-power settings for popcorn lithotripsy. BegoStones were fragmented in a glass bulb to simulate renal calyx, using a 120W Ho:YAG laser. A 242μm fiber was placed via the ureteroscope 2mm distance from stones (popcorn model). To assess the effect of pulse duration on fiber-tip degradation, long pulse (LP) and short pulse (SP) settings were compared at settings of 1.0Jx20Hz (20W), 0.5Jx70Hz (35W), and 1.0Jx40Hz (40W). To assess the effect of pulse energy on tip degradation, 40W SP settings (0.5Jx80Hz, 0.8Jx50Hz, and 1.0Jx40Hz) were tested. Pulse duration was measured using a photodetector and peak power was then calculated using the pulse duration and pulse energy. Experiments were conducted for 4min. Fiber-tip length was measured before and after using a digital caliper. Fiber-tip degradation was least when using LP for all settings tested (p < 0.01). For 40W settings, tip degradation was significantly lower when using a pulse energy of 0.5J compared to 0.8J or 1.0J (p < 0.004). LP mode results in less fiber burnback for all power settings tested. Total power is more important than frequency in the development of burnback. However, high-power 40W settings can be utilized with less burnback if lower pulse energies are used. Understanding these parameters can improve the longevity of the laser fiber and improve procedural efficiency.

Effects of irrigation parameters and access sheath size on the intra-renal temperature during flexible ureteroscopy with a high-power laser.

To investigate the effect of different laser power settings on intra-renal temperature (IRT) under different irrigation conditions during flexible ureteroscopy (FURS) in a live-anesthetized porcine model. Following ethics approval, 2 female pigs weighing ~ 28kg were used. Under general anesthesia, a percutaneous access was obtained to fix a K-type thermocouple inside the pelvi-calyceal system for real-time recording of IRT during FURS without UAS, UAS-10/12, UAS-12/14, and UAS-14/16F. A high-power holmium laser was used and the IRT was recorded during laser activation for up to 60s at a laser power of 20W, 40W, and 60W under gravity irrigation and manual pump irrigation. Under gravity irrigation, FURS without UAS was associated with hazardous IRT at a laser power as low as 20W for as short as 20s of laser activation. The IRT was rendered borderline when UAS was used. This UAS buffering effect disappeared with the use of higher laser-power settings (40W and 60W) with the maximal IRT exceeding 60°C. Moreover, laser activation at 60W was associated with very rapid increase in IRT within few seconds. Under pump irrigation, laser activation at the highest power setting (60W) for 60s was associated with a safe IRT, even without the use of UAS. The maximal IRT was below 45°C. The use of high-power Ho:YAG laser carries potentially harmful thermal effect when used under gravity irrigation, even when large-diameter UAS is used. High-power settings (> 40W) require high irrigation flow. The use of UAS is advisable to reduce the IRT and balance any intra-renal pressure increase.

MP04-02 THE ROLE OF PULSE DURATION AND PULSE ENERGY ON FIBER TIP DEGRADATION DURING HIGH-POWER HOLMIUM LASER LITHOTRIPSY

INTRODUCTION AND OBJECTIVE: High-power holmium lasers are becoming increasingly popular for ureteroscopic laser lithotripsy and dusting technique. Because settings and power selection may impact fiber-tip degradation and lithotripsy efficiency, we investigated the effect of pulse duration and pulse energy on fiber-tip degradation when using high-power settings for popcorn laser lithotripsy. METHODS: BegoStones were fragmented in an 11 mm bulb to simulate renal calyx, using a 120W Ho:YAG laser (Lumenis, CA). A 242 μm fiber (Boston Scientific, MA) was introduced through a ureteroscope mounted to a 3D positioner with its tip positioned at 2 mm distance from the stones (popcorn model). To assess the effect of pulse duration on tip degradation, settings with variable power of 1.0Jx20Hz (20W), 0.5Jx70Hz (35W), and 1.0Jx40Hz (40W) were tested on long pulse (LP) and short pulse (SP) modes. To assess the effect of pulse energy on tip degradation, high-power settings with equal power of 40W were tested (0.5Jx80Hz, 0.8Jx50Hz, and 1.0Jx40Hz) using SP. Experiments were conducted for a total duration of 4 minutes and outcome was fiber-tip length measured before and after each experiment using a digital caliper. Pulse duration and peak power were measured using a photodetector (DTE05D2, Thorlabs, NJ). RESULTS: Fiber-tip degradation was greatest when using SP compared to LP for all settings tested (P<0.01), with the highest degradation occurring at 1.0Jx40Hz using SP (Figure 1A). For 40W settings tested, tip degradation was significantly lower when using a pulse energy of 0.5J compared to 0.8J or 1.0J (P < 0.004; Figure 1B). Pulse energy of 0.5J at SP and LP had low peak power of 2.4 and 2.0 kW, respectively (Table 1). CONCLUSIONS: Using LP mode results in less fiber burnback for all power settings tested. High-power 40W settings can be utilized with minimal fiber burnback if low pulse energy settings are used. Understanding these parameters can help clinicians improve the longevity of the laser fiber and improve procedural efficiency.Source of Funding: Research grant form Boston Scientific

Use of a Novel Vacuum-Assisted Access Sheath in Minimally Invasive Percutaneous Nephrolithotomy: A Feasibility Study.

Objective: To assess the safety and efficacy of a novel vacuum-assisted access sheath (VAAS) in minimally invasive percutaneous nephrolithotomy (MPCNL). Materials and Methods: Seventy-five consecutive patients with single renal pelvic stone were treated with MPCNL combined with a novel VAAS. Patients' demographics and surgical outcomes, as well as perioperative and postoperative data, were recorded. Matched-pair analysis in a 1:1 scenario was done in patients who underwent MPCNL by peel-away access sheath (PAAS). All MPCNL was done with a rigid 12F mini-nephroscope and an 18F access sheath. MINDRAY-PM9000 monitor was used to record the renal pelvic pressure (RPP) data. Results: Patients' demographics, stone size, burden, and density (HU) were comparable between the two groups. Operative time was significantly shorter in the study group, at a mean of 32.4 ± 9.6 vs 46.2 ± 11.8 minutes (p < 0.001). The immediate stone-free rate was 89.3% for the VAAS group and 77.3% for the PAAS group (p = 0.049). Patients in the VAAS group had a lower visual analogue pain scale score at postoperative 6 and 24 hours. Mean perioperative RPP was lower in the VAAS group (10.3 ± 4.3 vs 17.8 ± 5.1 mmHg, p < 0.001). More than 50 seconds of accumulative time of high RPP (>30 mmHg) was shown in 13 patients of the VAAS group vs 30 of the PAAS group (p = 0.002). Conclusion: Combining VAAS with high-power holmium laser in MPCNL significantly improves the efficiency of stone retrieval with low RPP. This novel approach also reduces operative time, postoperative fever, and pain due to its simultaneous suction property.

Clinical Case Review - First HoLEP using Lumenis. LTD patented MOSES technology at the First center in Iraq using the Lumenis. LTD high-power holmium laser system Pulse 120H with Moses technology

Introduction: In Iraq Dr. Duraid Alhadithi Urologist at Al_Andulus urology clinic, has introduced a Holmium Laser Enucleation of the Prostate (HoLEP) service as the gold standard for the treatment of Benign Prostatic Hyperplasia (BPH). Materials and Methods: The Al_Andulus urology clinic, Iraq, purchased the first Lumenis.LTD high power Holmium Laser Pulse 120H with Moses technology system and Dr. Duraid Alhadithi said ‘although we start using lasers in treating BPH lately, we decided to start from the top and nothing is better now than the Lumenis. LTD Pulse 120H with Moses technology for HoLEP’. The patient for this clinical case review is the 6th patient in the series of 10 treated using the HOLEP with MOSES technology technique at the Al_Andulus urology clinic, Iraq, he is a 68-year-old smoker, echocardiography study was good EJ F 58 with pre-clinical studies of; • IPSS 26 • QoL 6 • Q max 8ml/sec • PSA 2, 85 PSA is 2.85 ng/ml • Prostate size 75ml by abdominal ultrasound with a middle lobe. And the digital rectal examination was of a uniformly enlarged firm prostate, median sulcus intact with no hard nodules. Results: The patient had an operation time 75 minutes including 10 minutes of Morcellation with no significant blood loss and no drop-in hematocrit a hospital stay of 18 hours total with catheter removal early in morning and the patient passed urine twice before discharge. Conclusion: In conclusion Dr. Duraid Alhadithi Urologist at Al_Andulus urology clinic, Iraq ‘After this surgery I believe that HOLEP with MOSES technology using the Lumenis.LTD Pulse 120H Holmium Laser System will be the gold standard method in treating prostates in Iraq due to many factors including minimal bleeding, minimal need for bladder irrigation post operatively, rapid recovery, early removal of catheter, and complete resection of the prostate gland comparing to traditional Trans Urethral Resection of the Prostate (TURP)’.

PD01-05 HIGH POWER HOLMIM MOSES TECHNOLOGY VERSUS SUPER-PULSE THULIUM FIBRE LASER. WHICH IS MORE EFFICIENT ON STONES?

INTRODUCTION AND OBJECTIVES:The Moses Technology developed to enhance the High power Holmium lasers (HPH) lithotripsy is challenged by the novel Super-pulse Thulium fibre laser. The goal of our stu...

V13 - High-power holmium laser with Moses technology: Our initial experience

V13 - High-power holmium laser with Moses technology: Our initial experience

386 - Super-pulse thulium fiber versus high power holmium lasers. What about temperature?

INTRODUCTION AND OBJECTIVES:A novel Super-Pulse Thulium Fiber laser has recently been developed and used for urolithiasis. The initial results show a better efficacy than conventional Holmium laser...

57 - High power Holmium laser ablation effect on kidney tissue. An evaluation of different laser settings correlated with the fibre-to-tissue distance

57 - High power Holmium laser ablation effect on kidney tissue. An evaluation of different laser settings correlated with the fibre-to-tissue distance

Low-Power Vs High-Power Holmium Laser Enucleation of the Prostate: Critical Assessment through Randomized Trial

ObjectiveTo assess the non-inferiority of Low-power Holmium laser enucleation of the prostate (LP-HoLEP) to high-power (HP-HoLEP) for enucleation efficiency pertaining to the advantages of lower cost and minimal postoperative dysuria, storage symptoms, and negative sexual impact. Patients and MethodsHoLEP was performed using 100W Versapulse, Luminis Inc., with 2J/25Hz for LP-HoLEP (61 patients) and 2J/50Hz for HP-HoLEP (60 patients).Two surgeons with different experience performed equal number of both procedures.Non-inferiority of enucleation efficiency (enucleated weight/min) was evaluated. All perioperative parameters were recorded and compared. Dysuria was assessed at 2 weeks by dysuria visual analog scale, urinary (Q.max and IPSS) and sexual (sexual health inventory for men score) outcome measures were evaluated at 1, 4, and 12 months. ResultsBaseline and perioperative parameters were comparable between the two groups. Mean enucleation efficiency was 1.42±0.6 vs 1.47±0.6 gm/min, P = .6 following LP-HoLEP and HP-HoLEP, respectively.Patients reported postoperative dysuria similarly in both groups as per dysuria visual analog scale. There was significant comparable improvement in IPSS (international prostate symptom score) and Q.max in both groups at different follow-up points. At one year, median IPSS and Q.max were comparable in both groups (P = .4 and .7 following LP-HoLEP and HP-HoLEP, respectively).Median postoperative reduction in prostate specific antigen was 89% (42:99) following LP-HoLEP vs 81% (62:94) after HP-HoLEP, P = .92.Both groups showed comparable perioperative and late postoperative complications. There were no statistically significant changes in the last follow-up sexual health inventory for men score in comparison to baseline score. ConclusionLP-HoLEP is non-inferior to HP-HoLEP in terms of all efficiency parameters regardless level of surgeon experience.

Caliceal Fluid Temperature During High-Power Holmium Laser Lithotripsy in an In Vivo Porcine Model.

With increasing use of high-power laser settings for lithotripsy, the potential exists to induce thermal tissue damage. In vitro studies have demonstrated that temperature elevation sufficient to cause thermal tissue damage can occur with certain laser and irrigation settings. The objective of this pilot study was to measure caliceal fluid temperature during high-power laser lithotripsy in an in vivo porcine model. Four female pigs (30-35 kg) were placed under general anesthesia and positioned supine. Retrograde ureteroscopy with entry into upper or middle calices was performed. Thermocouples were placed into the calix by open exposure and puncture of the kidney or retrograde alongside the ureteroscope. A 242 μm laser fiber was positioned in the center of the calix and activated (0.5 J, 80 Hz, 40 W) for 60 seconds with high, medium, or no irrigation delivered in each trial. Finite element simulations of laser-induced heating in a renal calix were also performed. Peak temperatures of 84.8°C, 63.9°C, and 43.6°C were recorded for no, medium, and high irrigation, respectively. Mean time to reach threshold of thermal injury (t43 of 120 minutes) was 12.7 and 17.8 seconds for no and medium irrigation. Thermal damage thresholds were not reached in high-irrigation trials. Numerical simulations revealed similar results with peak spatial average fluid temperatures of >100°C, 58.5°C, and 37.5°C during 60 seconds of laser activation for 0.1, 15, and 40 mL/minute irrigation, respectively. High-power holmium laser settings (40 W) can induce potentially injurious temperatures in the porcine in vivo model, particularly with slower irrigation rates. Characterization of thermal dose across a broader range of laser parameter settings is underway to map out the thermal safety envelope.

Low power vs. high power holmium laser enucleation of the prostate: Critical assessment through randomized trial

Low power vs. high power holmium laser enucleation of the prostate: Critical assessment through randomized trial

Thermal Response to High-Power Holmium Laser Lithotripsy.

The aim of this study was to investigate "caliceal" fluid temperature changes during holmium laser activation/lithotripsy using settings up to 40 W power output with different irrigation flow rates. The experimental system consisted of a glass test tube (diameter 10 mm/length 75 mm) filled with deionized water, to mimic a calix. Real-time temperature was recorded using a thermocouple (Physitemp, NJ) positioned 5 mm from the bottom of the tube. A 200 μm laser fiber (Flexiva; Boston Scientific, MA) was introduced through the working channel of a disposable ureteroscope (LithoVue; Boston Scientific) and the laser fiber tip was positioned 15 mm above the bottom of the test tube. Deionized water irrigation (room temperature) through the working channel of the ureteroscope was delivered at flow rates of 0, 7-8, 14-15, and 38-40 mL/minute. A 120-W holmium laser (pulse 120; Lumenis, CA) was used. The following settings were explored: 0.5 J × 10 Hz, 1.0 J × 10 Hz, 0.5 J × 20 Hz, 1.0 J × 20 Hz, 0.5 J × 40 Hz, 1.0 J × 40 Hz, and 0.5 J × 80 Hz. During each experiment, the laser was activated continuously for 60 seconds. Temperature increased with increasing laser power output and decreasing irrigation flow rate. The highest temperature, 70.3°C (standard deviation 2.7), occurred with laser setting of 1.0 J × 40 Hz and no irrigation after 60 seconds of continuous laser firing. None of the tested laser settings and irrigation parameters produced temperature exceeding 51°C when activated for only 10 seconds of continuous laser firing. High-power holmium settings fired in long bursts with low irrigation flow rates can generate high fluid temperatures in a laboratory "caliceal" model. Awareness of this risk allows urologist to implement a variety of techniques (higher irrigation flow rates, intermittent laser activation, and potentially cooled irrigation fluid) to control and mitigate thermal effects during holmium laser lithotripsy.