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Introduction: Manipulation of Holmium:Yttrium–Aluminum–Garnet laser parameters such as pulse energy (PE), frequency, and duration can impact laser lithotripsy ablation efficiency. In 2017, Lumenis introduced Moses™ Technology, which uses pulse modulation to enhance the delivery of energy from fiber to stone as well as to minimize stone retropulsion. Since the introduction of Moses Technology, other companies have brought additional pulse modulation concepts to market. The purpose of this in vitro study is to compare the pulse characteristics and stone ablation efficiency of Lumenis Moses Technology with Quanta's Vapor Tunnel™. Materials and Methods: Submerged BegoStone phantoms were systematically ablated using either the Lumenis Moses Pulse 120H or the Quanta Litho 100 clinical laser system. Two PEs (0.4 and 1 J), three fiber-stone standoff distances (SDs) (0.5, 1, 2 mm), and all available pulse duration and modulation modes for each laser were tested in combination. Fiber speed was adjusted to scan across the stone surface at either 1 or 10 pulses/mm to form single pulse craters or an ablation trough, respectively. Volumes of single craters and 1 mm trough segments were imaged and quantified using optical coherence tomography. Results: Ablation volumes decreased with decreasing PE and increasing SD. Statistically significant variability was seen between pulse types (PT) at every tested parameter set. Among pulse modulation modes, Moses Distance (MD) was superior at 0.5 mm in all testing and at 2 mm in trough testing. Vapor Tunnel (VT) was superior in 2 mm single crater testing. All modulated pulses performed similarly at 1 mm. Conclusions: In this benchtop model of laser lithotripsy, stone ablation was significantly impacted by PT. MD demonstrated superior or noninferior stone ablation at most tested parameters. VT maintained its efficacy the best as SD increased. Future work should focus on the mechanistic differences of these modes relative to other traditional laser pulse modes.

PURPOSE To present our preliminary results and describe a technical modification of mini-PCNL (12Fr) with the insertion of a ureteral access sheath (UAS) to facilitate the procedure. METHODS A prospective study for the time period of January 2020 to January 2021 was conducted including patients with renal stones sized ≤ 25 mm in whom prone mini-PCNL (tract size 12Fr) together with the retrograde insertion of UAS was performed. All patients had been prestented at least 1 week prior to the planned surgery. A single-step tract dilation to 12Fr diameter was performed through a nonpapillary medial puncture. The lithotripsy was achieved using high-power holmium yttrium aluminum garnet laser (Ho:YAG) with the 60 W power setting (40 Hz and 1.5 J). The follow-up investigations were planned at 1-month after the surgery. RESULTS In total, 32 patients with the median age and stone size of 56.5 (IQR = 53-62) years and 20.8 (IQR = 19.3-22.7) mm were included. The median operative and cumulative fluoroscopy time were 34.0 (IQR = 29.9-37.5) and 1.9 (1.8-2.1) min, respectively. The stone-free rate (SFR) at 1-month follow-up was 93.8% (30/32). Only one patient developed a fever and required prolonged antibiotic administration. None of the patients experienced clinically significant bleeding. CONCLUSION Our preliminary results showed that the use of UASs during mini-PCNL procedures is feasible and provides directed evacuation of the stone fragments reaching 93.8% SFR at a 1-month follow-up. Future well-designed studies are necessary to prove our findings.

Purpose The aim of this study was to compare the enucleation performances of four different types of laser devices in an ex-vivo experiment: a novel, pulsed Tm:YAG solid-state laser evaluation model (p-Tm:YAG), chopped thulium fibre laser (TFL), low-power Ho:YAG laser (LP-Ho:YAG), and a high-power Ho:YAG laser (HP-Ho:YAG). Methods Our primary aim was to endoscopically separate the fascial layers of a porcine belly using laser fibres within a time period of 60 s. The size of a “tissue pocket” was assessed numerically. The enucleation characteristics reflecting the surgeon’s experience were evaluated via the NASA Task Load Index (TLX) questionnaire and a questionnaire based on Likert scale. Results HP-Ho:YAG achieved with the available laser settings the largest overall “tissue pocket” (31.5 cm2) followed by p-Tm:YAG (15 cm2), TFL (12 cm2), and LP-Ho:YAG (6 cm2). The coagulation performances of p-Tm:YAG and TFL were rated the best. In the performance evaluation by the Likert questionnaire, HP-Ho:YAG (average score of 4.06) was rated highest, followed by p-Tm:YAG (3.94), TFL (3.38), and LP-Ho:YAG (3.25). The evaluation of the NASA-TLX performance questionnaire revealed average scores for HP-Ho:YAG, LP-Ho:YAG, TFL and p-Tm:YAG of 4.38, 4.09, 3.92 and 3.90, respectively. Conclusion We are the first to compare different laser devices and settings in an ex-vivo study. We found that the surgeons were most satisfied with the HP-Ho:YAG laser device, followed by the p-Tm:YAG. These findings could be highly relevant for future research and for the practical utilisation of laser systems in endourology.

Introduction: There are limited data regarding the effect of thulium laser (Tm:YAG) and holmium laser (Ho:YAG) on upper urinary tract. The aim of this study was to compare soft tissue effects of th...

Purpose The objective of this study is to evaluate the laser-tissue effects of laser radiation emitted by a newly developed high frequency pulsed Tm:YAG laser in comparison to the continuous wave Tm:YAG laser and the pulsed Ho:YAG laser. Methods Ex-vivo experiments were performed on freshly slaughtered porcine kidneys in a physiological saline solution. Experiments were performed using two different laser devices in different settings: A Tm:YAG laser was operated in a pulsed mode up to 300 Hz and in a continuous wave (CW) mode. Results were compared with a 100 W standard pulsed Ho:YAG laser system. Comparative tissue experiments were performed at 5 W, 40 W and 80 W. The incision depth and the laser damage zone were measured under a microscope using a calibrated ocular scale. Results Increased laser power resulted in increased incision depth and increased laser damage zone for all investigated lasers in this set-up. The Ho:YAG created the largest combined tissue effect at the 5 W power setting and seems to be the least controllable laser at low power for soft tissue incisions. The CW Tm:YAG did not incise at all at 5 W, but created the largest laser damage zone. For the new pulsed Tm:YAG laser the tissue effect grew evenly with increasing power. Conclusion Among the investigated laser systems in this setting the pulsed Tm:YAG laser shows the most controllable behavior, insofar as both the incision depth and the laser damage zone increase evenly with increasing laser power.

Objective To determine if MOSES technology improves efficiency and short-term outcomes in holmium laser ablation of the prostate (HoLAP). Methods A retrospective review of patients who underwent HoLAP between August 2016 and November 2019 was conducted. All procedures before and after the implementation of MOSES technology at our institution were evaluated. Preoperative patient characteristics and intraoperative data were collected. Postoperative International Prostate Symptom Score, quality of life, and postvoid residual measurements at 6 weeks and 3 months postoperatively were analyzed. Results This cohort included 65 males who underwent HoLAP, 32 without and 33 with MOSES. Patients in the MOSES group were slightly older, but no other differences in baseline characteristics were observed between the two groups. Ablation time was similar at 49.6 ± 26.1 minutes without and 40.7 ± 41.2 minutes with MOSES (P = .38). However, HoLAP with MOSES had significantly higher ablation efficiency (0.59 ± 0.24 g/min without vs 0.86 0.5 g/min with MOSES, P = .01). On multivariable regression modeling, HoLAP without MOSES added 12 minutes to operating time (estimate 12.3, standard error 3.44, P Conclusion Utilization of MOSES technology resulted in improved efficiency in HoLAP, translating into time savings in the operating room. Postoperative outcomes out to 3 months were similar among patients who underwent the procedure utilizing either laser pulse mode. Further studies are needed to investigate long-term outcomes as the use of MOSES is likely to become more commonly utilized.

Introduction: Many patients with non-muscle invasive bladder cancer (NMIBC) will develop recurrences of their tumour after their first resection. Flexible cystoscopy under local anaesthesia with Holmium-YAG laser ablation of tumour (FHoLAT) is safe, well tolerated procedure with significant cost savings when compared to cystoscopy under general or regional anaesthesia. We retrospectively analysed the outcomes of a large series of patients undergoing FHoLAT at our institution between April 2006 and September 2013. Patients and methods: Patients were offered FHoLAT if the tumour recurrence was small and/or they were deemed unfit for regional or general anaesthesia. Patient data was extracted from medical records. The primary outcomes were overall survival (OS), cancer-specific survival (CSS), progression-free survival (PFS) and recurrence-free survival (RFS). Results: 232 patients with a total 522 FHoLAT procedures were included. The median follow-up was 74.8 (43.5–101) months; 18% were discharged after a recurrence free follow-up duration; 52.2% had one FHoLAT, 19.8% had two FHoLATs, 11.2% had three FHoLATs and 16.8% had four or more FHoLAT. At initial diagnosis 24.1% of patients had G1pTa, 47% G2pTa, 9.9% G3pTa and T1 in 18.9%. 4.3% had concurrent carcinoma in situ. At 10 years, OS was 47.4%, CSS was 94.1%, PFS was 82.1%, RFS was 15.8%. Conclusions: FHoLAT for bladder tumour recurrences has an acceptable CSS and PFS for patients with small low-grade tumours or patients with high-grade or T1 tumours who are unfit for regional or general anaesthesia. The role of FHoLAT in unfit patients seems clear, but further prospective trials are needed to define its role in other patient groups, particularly high-grade NMIBC. Level of evidence: 3b-4

Background:Among various intracorporeal lithotripters, Pneumatic lithotriptorhas become the widely used tool for the treatment of ureteric stones. Recently the Holmium:YAG laser has been used with a wide range of potential urological applications, including intracorporeal lithotripsy of ureteric stones. Objective: To compare the treatment of upper ureteric stone between laser and pneumatic lithotripsy. Materials and methods: One hundred patients with upper ureteric stone who underwent ureteroscopic lithotripsy in the Department of Urology, CMH, Dhakafrom October 2012 to September 2015 were enrolled in this study. Patients were divided into two groups. Group A (LL) were treated with holmium: YAG laser and Group B (PL) were treated with pneumatic lithotripsy. Two procedures were compared in term of stone fragmentation, stone clearance rate, duration of lithotripsy, complications and duration of post operativehospital stay. Patients were monitored as outpatients after one month and after three months with a kidney ureter and bladder radiograph and ultrasonograph. Patients with migrated fragments or incomplete clearance underwent an auxiliary procedure such as Extra Corporeal shock wave lithotripsy (ESWL). Results: Mean stone size was 1.36 ± 0.36 cm in group A (LL) and 1.37± 0.36 cm in group B (PL). The immediate stone clearance rate was significantly higher inGroup A (94.0%) than Group B (76.0%). Fragments proximal migration were 6.0% in LL group and 24.0% in PL group. Use of stone retrieval equipments (baskets, forceps) was 16.0% and 64.0% in LL and PL group respectively (p

Background To evaluate the efficacy and safety of Holmium YAG laser circumcision in adolescents. Methods Eighty-one patients underwent circumcision for medical reasons, and patients’ requests were collected retrospectively during February 2017 to February 2019. They were divided into two groups: Holmium YAG laser (group 1, n = 41) and conventional group (group 2, n = 40). The guillotine method with a Holmium YAG laser was applied for circumcisions, and all the procedures were performed by a single urologist who was well-experienced with circumcision practices. Results The average age of group 1 was 15.53 ± 7.35 years old, and the average age was 16.34 ± 9.22 years old in group 2. There was no significant difference in age and indications. The average operative time was significantly shorter in group 1 than in group 2 (24.40 ± 3.94 vs. 27.25 ± 4.35 min, p p p Conclusions The use of Holmium YAG laser in circumcision is a novel, less complicated, easy, and less painful alternative procedure for circumcision in young males.

Objective To evaluate the outcomes of retrograde intrarenal surgery (RIRS) treatment of calyceal diverticular calculi and identify the associated factors affecting post-operative stone-free rate. Materials and methods From August 2015 to May 2019, data of 32 patients with calyceal diverticular calculi who were treated by RIRS in a Siriraj Hospital were retrospectively studied. All operations were performed by the same surgeon using flexible ureterorenoscopy (f-URS) and holmium YAG laser lithotripsy. Calyceal diverticula were identified by our refluxing technique and from the collected demographic, diverticular and stone data. Operative outcomes were retrospectively evaluated. Data were analysed to identify the factors associated with stone-free outcomes. Stone-free was defined as no residual stones remaining after surgery. Results Mean age of the patients was 55.7 years. Stone locations were non-lower pole in 81.2% of cases and lower pole for the remaining 18.8% of cases. Median stone size was 1.2 cm with three as the median number of stones per patient. Calcium oxalate was the most common stone composition (56.3%). Positions of the diverticulum were anterior calyx (34.4%) and posterior calyx (50%), while the remainder were undetermined (incomplete data). Average length of the diverticular neck was 0.4 cm. Mean operative time was 46 minutes and mean hospital stay was 2.9 days. Complications included fever in three patients (9.3%) and sepsis in two patients (6.3%), with overall post-operative stone-free rate at 75%. Factors significantly affecting stone-free status were stone size (P=0.003) and length of diverticular neck (P=0.038). Multivariate analysis determined that only stone size had a statistically significant effect on post-operative stone-free status (P=0.015). Cut off point for stone size that increased the chances of a post-operative stone-free outcome was less than 1.5 cm, as determined by the ROC curve. Conclusion RIRS was found to be an effective and safe treatment option for the removal of calyceal diverticular calculi. Stone size of less than 1.5 cm offered a better chance of post-operative stone-free condition.

INTRODUCTION AND OBJECTIVE:It is widely recognized that varying Holmium:YAG (Ho:YAG) laser parameters such as pulse energy, frequency, and duration can impact laser lithotripsy ablation efficiency....

A 12‐year‐old boy received steroid for his minimal change nephrotic syndrome for 10 years, and bilateral renal and ureteral stones and hydronephrosis were observed. Single‐use flexible ureteroscopy is usable for pediatric lithotripsy with Ho: YAG laser.

Objective: Transurethral lithotripsy using Holmium-YAG laser has been reported to be beneficial in breaking up bladder stones with large size (>4cm in diameter) with lower risk of mucosal injury and hematuria. The aim of this study is to evaluate the utilization of Holmium-YAG laser for the management of bladder stones at Kardinah General Hospital, Tegal. Material & Methods: This is a cross-sectional study conducted from January 2017 to March 2017. Patient’s demography, which included age, sex, length of surgery, stone size, and laser’s energy count were recorded. Results: We included 120 patients in this study. Mean of patients age in this study was 51.93 years old with age range were 41-85 years old. Most of the patients were male (109 vs 11) with a mean size of stone 25.09 ± 3.04 mm. Length of surgery ranges from 15 to 75 minutes and mean energy of the laser 28.99 ± 19.34 kJ. There was 100% stone’s clearance following surgery with no major complication occurred. Conclusion: Holmium-YAG laser is effective in managing bladder stones at Kardinah General Hospital particularly for large size stones. Length of surgery and energy of laser used depend on the stone size in which bigger stone size is associated with longer surgery time and bigger laser energy needed.

Introduction: The retrograde approach is a modification that makes the percutaneous cystolitholapaxy (PCCL) a more trendy method, especially in operating rooms with limited facilities. The transurethral approach for bladder calculi lithotripsy by a laser has become popular among urologists. In this study, we investigate the feasibility and safety of retrograde assisted access for PCCL in comparison with transurethral cystolithotripsy by the holmium-YAG laser (Ho: YAG). Methods: According to the type of intervention, the patients were stratified to two matched groups. In the retrograde-assisted percutaneous cystolitholapaxy (RPCCL) group, a Benique was conducted through the urethra into the bladder; palpating the suprapubic region, an about 1.5 cm incision was done over the tip, then an Amplatz sheath was placed over it, treading into the bladder; further cystolitholapaxy was done by a routine order. In transurethral Ho: YAG laser lithotripsy (TULL) via 200 µm fiber vaporize the stone. Results: A total of 124 male patients with the mean age of 50.33±9.64 years and the average stone burden of 3.35±1.07 cm were included in the study. The most common cause of vesical calculi was spinal cord injury. Statistically significant differences were found in terms of the mean operation time in favor of the RPCCL group (P≤0.05) and the mean hospital stay in favor of the TULL group (P≤0.05). The stone-free rate (SFR) was 100% in both methods after a onemonth follow-up. None of the interventions changed to open surgery. There were not any major complications in both methods. Conclusion: RPCCL is a safe and effective method in bladder stone treatment and is applicable in medical centres without Ho: YAG equipment.

Introduction: Transurethral lithotripsy (TUL) is an appropriate treatment for ureteral stones and is usually used for stones in the middle and lower part of the ureter. Different devices such as the Holmium laser, the stone basket, and the stone cone exist to prevent any fragments from retropulsion during TUL. The present study aims to compare the advantages and disadvantages of the Holmium laser, the stone basket, and the stone cone. Methods: A retrospective study was conducted from September 2016 to January 2018 comparing various TUL methods in 88 subjects with proximal ureteral calculi. The study participants were divided into 4 matched groups. The first one included 20 patients undergoing TUL with no device (group 1), the second group included 22 patients undergoing TUL while using the stone retrieval basket, the third group included 18 patients undergoing TUL while utilizing the stone cone and the fourth group included 28 patients undergoing TUL while using the Hol-YAG laser. Results: A residual stone ≥3 mm was recorded in 15.9% of the patients. The stone free rate was seen in 100%, 90.9, 83.3%, and 55% of the Holmium laser group, the retrieval basket group, the stone cone group and the no device group respectively (P=0.001). The lowest rate of surgery complications including ureteral perforation, post-operative fever, and mucosal damage between the 4 groups (P=0.003) and the highest time of surgery (P=0.001) belonged to the laser group. If we want to ignore the laser group, the success rate for lithotripsy was better in both groups with a stone retrieval device compared to the no device group, but no advantage existed between the stone basket and the stone cone. Conclusion: We can safely conclude that lasers significantly help to prevent stone migration during TUL. If we want to ignore the laser group, the success rate for lithotripsy was significantly better in both groups with a stone retrieval device compared to the no device group, but no advantage existed between the stone basket and the stone cone.

Background: Shockwave Lithotripsy (SWL) and ureteroscopy using Holmium Laser are effective and minimally invasive procedures for treating proximal ureteric stones ≤ 1.5 cm. However, there is still a debate of which one is more suitable for the proximal ureteric stones. Different studies have reported a variety of outcomes of SWL and ureteroscopy, as the both treatments use advanced instruments, they offer few complications and good outcomes among urologists. Objective: To evaluate the safety and efficacy of ureteroscopy using Holmium YAG LASER for proximal ureteric stone ≤ 1.5cm compared to SWL. Patients and Methods: It was a randomized prospective trial comparing ureteroscopy with HO: YAG Laser to (SWL) in managing proximal ureteric stones, done in the period from April 2018 to April 2019. It included 40 patients with upper ureteral stones and were randomly divided into two groups: Group A: 20 patients treated by ESWL. Group B: 20 patients treated by ureteroscopy using LASER lithotripsy. Results: There was no significant difference between the two groups regarding patients and stones criteria as maximal diameter, HU and position opposite vertebrae, degree of hydronephrosis and overall success rate. Conclusion: ESWL and Ho-YAG laser lithotripsy are comparable in managing proximal ureteric stones in term of safety and efficacy. URS has the advantage of higher SFR from the first session and prolonged radiation exposure time. ESWL has the advantage of no need of anesthesia and no hospital stay as it was done as outpatient and this should be considered when counseling the patient with proximal ureteric stone.

A superpulse (500 W peak power) thulium fiber laser operating at a 1940 nm wavelength, suitable for lithotripsy, has recently been developed. The goal of this study was to compare stone fragmentation and dusting performance of the prototype superpulse thulium fiber laser with leading commercially available, high-power holmium:YAG lithotripters (wavelength 2100 nm) in a controlled in vitro environment. Two experimental setups were designed for investigating stone ablation rates and retropulsion effects, respectively. In addition, the ablation setup enabled water temperature measurements during stone fragmentation in the laser–stone interaction zone. Human uric acid (UA) and calcium oxalate monohydrate (COM) stones were used for ablation experiments, whereas standard BegoStone phantoms were utilized in retropulsion experiments. The laser settings were matched in terms of pulse energy, pulse repetition rate, and average power. At equivalent settings, thulium fiber laser ablation rates were higher than those for holmium:YAG laser in both dusting mode (threefold for COM stones and 2.5-fold for UA stones) and fragmentation mode (twofold for UA stones). For single-pulse retropulsion experiments, the threshold for onset of stone retropulsion was two to four times higher for thulium fiber laser. The holmium:YAG laser generated significantly stronger retropulsion effects at equal pulse energies. The water temperature elevation near the laser-illuminated volume did not differ between the two lasers. Distinctive features of the thulium fiber laser (optimal wavelength and long pulse duration) resulted in faster stone ablation and lower retropulsion in comparison to the holmium:YAG laser.

Introduction and Objectives: The Moses effect (ME) was described >30 years ago during normal laser functioning in a fluid medium. Recently, a laser device equipped with a pulse-modulating system called Moses™ technology (MT; Lumenis®) was marketed for both stone lithotripsy and prostate endoscopic surgery. We aimed to perform a literature revision of ME from a historical perspective up until its present-day applications. Evidence Acquisition: A search of Medline, PubMed, and Scopus was performed to identify articles published in English within the past 30 years addressing both ME and MT in relation to their urologic applications. Relevant studies were then screened, and the data were extracted, analyzed, and summarized. The preferred reporting items for systematic reviews and meta-analysis criteria were applied. Results: ME was first described in 1986 during endovascular laser tissue ablation. During the late 1980s and the early 1990s, the interest raised around ME led to its characterization and better definition. Despite this initial interest, ME gradually disappeared from the focus of researchers and clinicians. In 2017, MT was launched on the market, although postmarketing comparative efficacy and safety data are lacking. Conclusions: Although ME had been described and characterized during normal laser functioning >30 years ago, only very recently it began to regain some consideration after the marketing of MT, whose clinical outcomes are still awaited.

Introduction: Many valid option modalities are available for the management of urethral stricture disease (USD), such as internal urethrotomy which has the success rates of 33%–60%. The aim of this study was to assess the outcome of holmium: YAG (Ho: YAG) laser urethrotomy (HLU). Methods: One hundred thirty-eight patients with urethral stricture with the mean age of 48±3.03 years old treated by HLU from March 2011 to August 2017. The main purpose of this investigation was to evaluate mean operation time, stricture recurrence rate and post-operation Qmax and complications of transurethral HLU. Results: The most common cause of USD was trauma in 82 (59.4%) patients. Mean laser operation time, mean hospital stay and mean postoperative duration of catheterization were 23.08 ± 9.1 minutes, 19.02 ± 10.7 hours and 10.3 ± 1.05 days respectively. The mean Qmax was 8.3 ± 2.07 mL/s before surgery and 16 ±3.1 mL/s afterward. At the end of 12 months follow-up, a total of 37 (26.8%) patients developed recurrence of the stricture. Patients with posterior, longer urethral strictures and previous history of interventions have more recurrence rate of the stricture. Conclusion: HLU is minimally invasive and seems to be an effective and safe management option for primary, short, urethral strictures. The hospital stay is remarkably short and complications are negligible.

Background: Holmium:yttrium-aluminium-garnet (Ho:YAG) laser lithotripsy with ureteroscopy (URS) was a safe and successful treatment option for pediatric ureteral stones. We aimed to comparatively evaluate the outcomes of 15 and 30 W Ho:YAG laser lithotriptors in pediatric ureter stones. Materials and Methods: We retrospectively evaluated 55 children who underwent ureteroscopic laser lithotripsy to treat ureter stone size up to 15 mm between September 2009 and March 2020. Groups were formed according to the laser lithotriptor power 15 W (Group 15: n = 32), 30 W (Group 30: n = 23). The efficiency of laser lithotriptors was compared between the groups. Results: The age, gender, and stone characteristics (longest stone diameter, density, location and multiple stones) were similar between the groups. In the postop first month, stone-free status was achieved in all cases except one child in Group 15. The median operative time was significantly shorter in Group 30 (40 minutes) than in Group 15 (52.5 minutes) (P = .010). Clavien-Dindo class (CDC) 2 complications occurred in 2 children in both groups (P = .597). Although ureteric stenosis was observed in 1 patient in Group 15, no ureteric stenosis was seen in Group 30 during follow-up (median 16.1 months). Length of hospital stay (LoHS) and stone-free rates were similar between groups. Conclusion: URS with 15 and 30 W Ho:YAG laser lithotriptors is an effective treatment option for pediatric ureteral stones with a high success rate and low complication rates. In brief, 30 W Ho:YAG laser lithotriptors should be preferred over 15 W lithotriptors due to their shorter operative time with similar success rate.

Introduction: The super pulse thulium fiber (SPTF) laser has recently been acclaimed by more efficient lithotripsy activities, shorter laser, and treatment times demonstrated in preclinica...

The aim of this study is to present our experience on the use of the holmium:yttrium-aluminum-garnet (Ho:YAG) laser in pediatric patients for pediatric urolithiasis and describe the optimal settings. A total of 116 children who underwent urolithiasis treatment (percutaneous nephrolithotomy (PNL), ureterorenoscopy (URS), retrograde intrarenal surgery (RIRS)) were included. The mean age of the patients was 8.4 ± 5.2 years (1-18). The mean follow-up was 26 ± 8.8 months (9-45). There was no difference between the mean stone sizes of PNL and RIRS patients (p = 0.816). Operations were performed with 200, 272, and 365-μm fibers. In mini-URS, stone fragmentation was achieved with the energy settings set between 0.5 and 1 J and frequency set to > 8 Hz. In RIRS, fragmentation was achieved with the setting of 0.5-0.8 J at 10-20 Hz. Stone fragmentation was performed with energy settings of 0.8 to 2 J between 5 and 15 Hz for PNL. There was no significant difference between the stone-free rates of the PNL and RIRS (p = 0.150). Four postoperative complications occurred (Clavien II), which included febrile urinary infections in two patients who underwent mini-URS, one patient who underwent PNL, and one patient who underwent RIRS. Our results confirmed that Ho-YAG laser can be effectively used in children for stone treatment by using low-energy high-frequency settings for URS and RIRS and a high energy setting for PNL.

Introduction: Genital condylomatosis is a highly contagious disease caused by the human papilloma virus (HPV). The aim of this prospective multicentre study was to evaluate the safety and efficacy of the Holmium:YAG (yttrium-aluminium-garnet) laser in the treatment of genital and intra-urethral warts; the secondary aim was to assess the patients’ postoperative satisfaction and cosmetic results. Methods: From December 2016 to March 2019, patients with genital warts were prospectively enrolled in three hospitals. The inclusion criteria were male gender, age over 18 years-old and treatment-naïve. External and urethral genitalia warts were treated by the Holmium YAG laser. The follow-up analysis consisted of physical examination, flexible urethro-cystoscopy in case of meatal lesions, and administration of Dermatology Quality of Life Index (DLQI) and Patient Global Impression of Improvement (PGI-I) questionnaires at 1, 3, 6 and 12 months after surgery and subsequently yearly. Results: Sixty patients were enrolled. The single treatment was effective in 57/60 patients (95%). At a mean follow-up of 26 months, recurrences occurred in 8 patients (13.3%). No peri- or post-operative complication occurred. An improvement in pre-operative condition was highlighted with PGI-I and DLQI questionnaires. Conclusion: Our prospective multicentre study showed that holmium laser surgery seems to be a safe and effective treatment for external genital and urethral warts. Good dermatological outcomes aid to further improve patient satisfaction.

The word LASER stands for Light Amplification by Stimulated Emission of Radiation. The use of laser in spine surgery is not yet more widespread compared to other medical fields. However, there is a great advantage of minimizing damage to surrounding normal structures including nerve tissues when surgery is performed using a laser. Currently, CO2 laser is used when performing discectomy using a microscope, and holmium YAG (Ho:YAG) laser and neodymium-doped YAG (Nd:YAG) laser are used when performing discectomy using an endoscope. With the diversification of media and the development of laser machines, various types of lasers are being developed, so we look forward to the day when they will be applied to and develop the spine surgery.

INTRODUCTION AND OBJECTIVE:The latest developed laser energy modalities provide higher amounts of energy promising better results for urinary stone treatment. Higher amounts of energy can lead to a...

Intraoperative iatrogenic burns that occur under general anesthesia may become deep and wide, because patients do not notice or complain about them. We here present a patient who suffered burns to both the buttocks and thighs from a holmium YAG laser used during surgery for cervical cancer. An investigating committee was set up to determine the cause of this incident, and concluded that it was highly likely that the patient’s flammable gastrointestinal gases during the use of the holmium YAG laser caused the fire.This case report describes the etiology of this unusual incident, together with a literature review, and recommendations on how to avoid such injuries. In addition, we report the successful treatment of this patient by a strategic surgical method. Keywords: Iatrogenic burns, Gastrointestinal gas explosion, Holmium YAG laser

Introduction: Bladder stone is more common in developing countries and it is one of the rare diseases affecting children. In recent years, there is an increasing tendency in urologists to have minimal invasive approaches. The aim of this study was to compare the results of surgical bladder stone management in our single tertiary center. Methods: From 159 children younger than 18 years with vesical stones treated during January 2000 to January 2015 in Shohada-e-Tajrish hospital, Tehran, Iran, 146 subjects entered to the study. According to type of intervention, patients stratified to three groups. First group included 80 patients that open cystolithotomy (OCL) was done for them, second group was 39 patients who underwent percutaneous cystolithotomy (PCCL) and third group was 27 patients who treated by transurethral cystolithotripsy with holmium-YAG laser (TULL). Demographic data, hospital stay, operation time, and post operation complications were recorded and comparison were drawn between the three groups. Results: Mean age was 8.3±5.1 years (8.6±5.1, 6±4.2 years for boys and girls, respectively). Mean stone size (MSS) was 2.76±1.07 cm and no significant differences were found between the three groups but it was larger in OCL group. Mean operative time (MOT) was 29.15±7.12 minutes in separate; MOT in TULL was significantly higher than PCCL and OCL respectively (36.3±5.97, 30.54±5.27 and 26.06±6.32 minutes/P =0.000). Mean hospital stay (MHS) in OCL group was 3.55±1 days that was higher than PCCL and TULL groups significantly (P =0.000). Conclusion: Based on our study, holmium:YAG lithotripsy has a high success rate, and is a minimally invasive management, therefore it is a safe method for children bladder calculi treatment if proper equipment was available and done by expert hands.

Among the many devices for lithotripsy inside the body, the lithotripsy device using the Holmium-YAG laser has evolved into the widely used tool for treating urinary tract stones. Purpose: The aim of this research is to show the effect of parameters for Ho-YAG laser (2100 nm) on fragmentation time Intra Corporeal and stone composition for stone disease through is to investigating of stone composition and setting pulsed holmium laser energy with calculating time period for crushing stone. Patients & Methods: from the period of March 2020 to august. 2020 a 63 patient were selected to include in this study (outcome of surgery for lithotripsy ureteral stone below 17 mm by laser) has been 10-85 years for male and female collected from the Hussein Teaching hospital department of urology. using Ho- YAG laser irradiation wave length 2.12 μw interaction absorption coefficient (30 cm-1) at maximum output power 0.5-1.2J for width of the laser pulse is 350 microseconds in an optical fiber with a diameter of 272-550 microns with an energy of 0.8 - 1.2 joules at 6-10 hertz. The samples obtained were selection collections of fragments retrieved following lithotripsy. The aim of this study was to determine the chemical compositions of urinary stones that had been removed, Use infrared spectroscopy Within the range (400-4000) cm-1 using a (Bruker FTIR - Spectrometer) device. Results: This study show mean stone size below 14 mm was (2.758±0.919) mm for First group of 21 stones of the same composition ( oxalate calcium ) with pulse energies of o.8, 1.2 and 1.2 J with repetition rate was 6, 8 and 10 HZ respectively for ureteric stone which included 12 male 57.14 % with 9 female 42.85 %. second groups of 21 stones of the same composition (Uric acid) with pulse energies of o.8, 1.2 and 1.2 J with repetition rate was 6, 8 and 10 Hz respectively for ureteric stone below 17 mm which comprised 13 male 61.9 % with 8 female 38.09 % Third group of 21 stones of the same composition (Struvite Stones) with pulse energies of o.8, 1.2 and 1.2 J with repetition rate was 6, 8 and 10 HZ respectively for ureteric stone below 16 mm which included 11 male 52.3 % with 10 female 47.61 % Conclusion: That Ho-YAG Laser lithotripsy of ureteral stones is an excellent treatment method, which is related to the period of time required for fragmentation with the type of stones and the different laser settings used.

Objectives: The aim of this study was to describe a novel negative-pressure laser lithotripsy device to overcome the deficiencies of the conventional procedure. Patients and Methods: Between August 2018 and March 2019, 78 patients with a single ureteral stone underwent retrograde ureteroscopy with a Wolf 8F/9.8F rigid ureteroscope and a 200-μm holmium-YAG laser. The mean stone size was 11.8 mm, measured for the maximum length. The negative-pressure laser lithotripsy device consists of an F5 ureter catheter and a T joint. The closed tip of an F5 ureter catheter is cut off, and it is then inserted within one opening of the T joint. The 200-μm laser fiber is introduced into the ureteral catheter through the other opening of the T joint. The third opening of the T joint is connected to the negative-pressure pipe. The valve end of the Foley catheter is used for sealing the cap. Continuous suction and active irrigation throughout the lithotripsy could maintain adequate visibility. Results: All ureteroscopic procedures were successful. The negative-pressure device showed good stone retention capabilities, with no observed stone migration. We did not observe any major complications. The stone-free rate was 97.44% (76/78), demonstrated on plain radiography of the kidney-ureter-bladder on the first postoperative day. The stone-free rate after 1 month was 100%. Conclusions: The negative-pressure ureteroscopic lithotripsy is easy and safe management for the ureteral stones. It might reduce the risk of stone fragment retropulsion, improve surgical vision, shorten the operative time, and decrease the renal pelvic pressure.

A 27-year-old male presented with recurrent urinary tract infections, calculus formation and hair follicles in urine following urethroplasty. The patient was treated with urethroscopic holmium laser in 2012, which was performed by Beiko for the first time in the literature to remove stones and epilate hair follicles. At 3-month, 3-year and 6-year follow-ups, the patient was symptom and infection-free. Urethrocystoscopy was performed in the 6-year follow-up, and no stone formation was observed. There were only a few hair follicles that were too short to require re-surgery. Urethral hair follicles and stone formation are uncommon long term complications following urethroplasty. Endoscopic holmium laser hair epilation is a rarely performed treatment option for hair follicles and urethral stone. Holmium:YAG laser epilation may be an alternative, minimally invasive treatment option with successful long term outcomes., 27 yaşında erkek hasta, tekrarlayan idrar yolu enfeksiyonu, idrarda taş oluşumu ve idrarla kıl gelmesi şikayetleri ile başvurdu. Hasta 2012 yılında, Beiko tarafından literatürde ilk kez uygulanan üretradan taş çıkarmak ve kıl köklerinin epilasyonu için yapılan üretroskopik olarak holmium lazer ile tedavi edildi. Kısa süreli 3.ay ve uzun süreli 3 ve 6 yıllık takiplerde hastada enfeksiyon gelişmedi. Üretrosistoskopi 6.yıl takibinde yapıldı. Üretrosistoskopide cerrahi gerektirecek taş ve kıl kökü oluşumu görülmedi. Semptom vermeyen ve cerrahi gerektirmeyecek kadar kısa olan birkaç kıl kökü görüldü. Üretral kıl folikülleri ve taş oluşumu, üretroplastiyi takiben nadir görülen uzun dönem komplikasyonlardır. Endoskopik holmium lazer epilasyonu kıl kökleri ve üretra taşı için nadiren uygulanan bir tedavi seçeneğidir. Holmium:YAG lazer epilasyonu minimal invaziv yaklaşım ve iyi uzun dönem sonuçlar ile alternatif bir tedavi seçeneği olabilir.

Background Anal canal condylomata acuminata is a disease caused by the human papilloma virus. Conventional cauterizing laser treatment cannot achieve a satisfactory result owing to a high recurrence rate, and the application of 5-aminolaevulinic acid-photodynamic therapy (ALA-PDT) also has limitations in the anal canal. Holmium yttrium aluminum garnet (Ho: YAG) laser with fiber is found to be effective at removing canal lesions, and may create suitable conditions for ALA-PDT. We aim to investigate the feasibility of Ho: YAG laser combined with ALA-PDT and to explore a more optimal therapy in refractory anal canal condylomata. Methods Data of 37 patients with anal canal condylomata (number of warts≥ 10 lesions) from May 2017 to March 2019 were reviewed. In total 17 cases were treated with Ho: YAG laser plus ALA-PDT, and 20 patients treated with CO2 laser plus ALA-PDT were selected as control. Wart clearance and recurrence rates were evaluated as well as laser complications. Results Most warts (88.23 %) were removed after a session of Ho: YAG laser pretreatment. The average number of laser sessions required to clear all warts was 1.94 in the Ho: YAG laser plus ALA-PDT group. Meanwhile, no wound infections or defecation disfunctions were found. Ho: YAG laser with ALA-PDT could significantly reduce wart recurrence rates (17.6 %) in comparison with CO2 laser with ALA-PDT (55 %). Conclusions Ho: YAG laser combined with ALA-PDT raised the cure rate of refractory anal canal condylomata and has important guidance implications for clinical application.

Summary Introduction To the best of our knowledge, no pediatric paper has been published regarding specifically how to set the Holmium:YAG laser for multiple urologic applications. Objective To provide insight into the laser parameters for pediatric applications. Study design We describe the principle and the settings of the laser. Results The Holmium:YAG laser can produce four different biological effects: (1) fragmentation of stones in small fragments that can be retrieved with grasping instruments, thereby increasing the immediate stone-free outcome. For fragmentation lithotripsy, the laser has to be set with a high energy, low frequency and short pulse duration; (2) dusting which produces fine dust that can spontaneously evacuate, avoiding the use of basket retrieval. The dusting setting requires low energy, high frequency and long pulse duration; (3) incision of posterior urethral valves or ureterocele when all settings are maximized: high energy, high frequency and long pulse duration; (4) coagulation of urothelial tumors using high frequency, long pulse duration and slightly lower energy than required for incision. Discussion Both dusting by painting and fragmentation with retrieval for ureteroscopic laser lithotripsy are effective. Although dusting tends to be associated with shorter operative times and a lower risk of ureteral trauma, this approach has a potential risk of recurrent stone formation from dust failing to pass. In contrast, fragmentation with extraction may provide for a more immediate postoperative stone-free result. Altering the pulse energy, frequency, width and modulation can help to optimize lithotripsy efficiency. Lower pulse energy settings result in smaller fragments, less retropulsion and reduce fiber tip degradation. A shallow depth of penetration in water and tissue allows precise energy application and provides a margin of safety. Conclusion An understanding of Ho-YAG laser settings will permit the pediatric surgeon to make a better use of the device for different urological applications. Download : Download high-res image (469KB) Download : Download full-size image Figure Summary . Laser settings for pediatric endourology.