Efficacy and safety of Ho:YAG laser lithotripsy for ureteroscopic removal of proximal and distal ureteral calculi

To Evaluate the Impact of Ho:YAG Laser Lithotripsy for Ureteroscopic Removal of Proximal and Distal Ureter Calculi

Background Urinary calculus illness is a prevalent clinical issue encountered by the medical community, particularly urologists, in contemporary society. Laser technologies have been widely accepted as standard modalities for lithotripsy applications. Using the Ho:YAG laser has expanded the range of applications for ureteroscopic stone management (URS), enabling the treatment of bigger stones in all regions of the upper urinary tract. It is noteworthy that ureteroscopy (URS) demonstrates superior rates of stone clearance for distal stones, regardless of their size, with a success rate of 94.5% compared to 74% for other treatment modalities. Significant variation exists in the reported results and problems associated with Ho:YAG laser lithotripsy across different trials, as documented in the literature. The procedure's outcome might vary based on factors such as the size of the stone, the length of impaction, the presence of ureteral damage and granulation, the kind and size of endoscopes used, and the specific energy settings employed by various operators. The present study aimed to evaluate the impact of Ho:YAG laser lithotripsy for ureteroscopic removal of proximal and distal ureter calculi. Methods This prospective observational study was carried out in the Department of Urology at DY Patil Medical College and Hospital, Pune, from March 2021 to March 2023. Patients diagnosed with a case of ureteric stone who opted for URSL during the study period were included. A total of 50 patients who underwent URSL in the urology department were included in this study. These were then grouped into those with proximal ureteral stones and distal ureteral stones. (25 each) Results The study observed that patients diagnosed with proximal ureteral stones had bigger calculi, with a mean stone size of 15mm, in comparison to patients with distal ureteral stones, with a mean stone size of 10mm (P=0.010). The stone burden was significantly higher for proximal ureteral stone patients than those with distal ureteric stones (P=0.010). The average duration of the operating procedure for upper ureter stones was 70 minutes, but for lower stones, the mean operative time was 45 minutes (P<0.001). No statistical significance was seen in the median age of patients between the two groups (P=0.89). The maximum number of cases in the upper stone group were in the age group of 16-30 years, and in the lower stone group was in the age group of 31-45 years. The prevalence of DJ stents at the time of presentation was higher among patients diagnosed with proximal ureteric stones than those with distal ureteric stones, with rates of 28% and 20%, respectively (P=0.508). Full fragmentation was successfully accomplished in all patients within the distal calculus group, accounting for 100% of the cases. At the same time, for proximal ureteric stones, a single laser lithotripsy session resulted in 92% (23 patients) achieving a stone-free status after two weeks.  Conclusion The study observed that stone size, burden, and procedure duration were statistically significant among other criteria. Mean age, stone HU, prior DJ stent, and stone-free rate were statistically insignificant. The procedure indicated that Ho:YAG laser lithotripsy has efficacy in treating both proximal and distal ureteral stones, with minimal intraoperative and postoperative complications. None of the complications were due to laser energy.

The Effects of Scanning Speed and Standoff Distance of the Fiber on Dusting Efficiency during Short Pulse Holmium: YAG Laser Lithotripsy

To investigate the effects of fiber lateral scanning speed across the stone surface (v_fiber) and fiber standoff distance (SD) on dusting efficiency during short pulse holmium (Ho): YAG laser lithotripsy (LL), pre-soaked BegoStone samples were treated in water using 0.2 J/20 Hz at SD of 0.10~0.50 mm with v_fiber in the range of 0~10 mm/s. Bubble dynamics, pressure transients, and stone damage were analyzed. To differentiate photothermal ablation vs. cavitation damage, experiments were repeated in air, or in water with the fiber tip at 0.25 mm proximity from the ureteroscope end to mitigate cavitation damage. At SD = 0.10 mm, the maximum dusting efficiency was produced at v_fiber = 3.5 mm/s, resulting in long (17.5 mm), shallow (0.15 mm), and narrow (0.4 mm) troughs. In contrast, at SD = 0.50 mm, the maximum efficiency was produced at v_fiber = 0.5 mm/s, with much shorter (2.5 mm), yet deeper (0.35 mm) and wider (1.4 mm), troughs. With the ureteroscope end near the fiber tip, stone damage was significantly reduced in water compared to those produced without the ureteroscope. Under clinically relevant v_fiber (1~3 mm/s), dusting at SD = 0.5 mm that promotes cavitation damage may leverage the higher frequency of the laser (e.g., 40 to 120 Hz) and, thus, significantly reduces the procedure time, compared to at SD = 0.1 mm that promotes photothermal ablation. Dusting efficiency during short pulse Ho: YAG LL may be substantially improved by utilizing an optimal combination of v_fiber, SD, and frequency.

Evaluation of the relation between size of stone and its attenuation measured by Hounsfield units and the total laser energy required to fragment it

BACKGROUND

Anticipating the total laser energy (TLE) of Holmium YAG laser required for ureteroscopic (URS) lithotripsy is essential to guide urologists in selecting the optimal fiber size. This study aimed at evaluating the relationship between stone size and stone attenuation measured by HU as predictors for the TLE during the procedure.

METHODS

We conducted an observational prospective cohort study of patients undergoing URS lithotripsy at the Urology department of Ain Shams University Hospitals from September 2018 to September 2019 with the use of a holmium YAG laser as the lithotripsy method. Patients' demographic and clinical characteristics, stone location, stone size, stone attenuation measured by HU from the non-contrast CT, TLE, and procedure time were recorded. Data were analyzed using Jamovi software (version 2.0 for macOS).

RESULTS

Forty patients were included in the study (22 males and 18 females) with a mean age of 57.8 years. The mean stone size was 9.8 mm³, the mean HU was 858.8 units, and the mean TLE was 3.5 KJ. Both stone size and stone attenuation measured by HU were positively correlated with TLE (r = 0.81 and 0.84, respectively; p < 0.001 for both). Further, regression analysis showed that both variables could significantly predict the TLE (ß = 0.001 and 0.71, respectively).

CONCLUSIONS

Both stone attenuation, as measured by HU, and stone size positively correlate with TLE required for URS lithotripsy. Therefore, both HU and stone size can predict the TLE, which will be helpful to guide the urologist in selecting the optimal fiber size for the procedure.

New Generation Pulse Modulation in Holmium:YAG Lasers: A Systematic Review of the Literature and Meta-Analysis

(1) Background: New pulse modulation (PM) technologies in Holmium:YAG lasers are available for urinary stone treatment, but little is known about them. We aim to systematically evaluate the published evidence in terms of their lithotripsy performance. (2) Methods: A systematic electronic search was performed (MEDLINE, Scopus, and Cochrane databases). We included all relevant publications, including randomized controlled trials, non-randomized comparative and non-comparative studies, and in-vitro studies investigating Holmium:YAG lithotripsy performance employing any new PM. (3) Results: Initial search yielded 203 studies; 24 studies were included after selection: 15 in-vitro, 9 in-vivo. 10 In-vitro compared Moses with regular PM, 1 compared Quanta’s, 1 Dornier MedTech’s, 2 Moses with super Thulium Fiber Laser, and 1 compared Moses with Quanta PMs. Six out of seven comparative studies found a statistically significant difference in favor of new-generation PM technologies in terms of operative time and five out of six in fragmentation time; two studies evaluated retropulsion, both in favor of new-generation PM. There were no statistically significant differences regarding stone-free rate, lasing and operative time, and complications between Moses and regular PM when data were meta-analyzed. (4) Conclusions: Moses PM seems to have better lithotripsy performance than regular modes in in-vitro studies, but there are still some doubts about its in-vivo results. Little is known about the other PMs. Although some results favor Quanta PMs, further studies are needed.

Clinical Observation of UreTron Single-Probe Ultrasonic Intracorporeal Lithotripter for Ureteral Calculi

Objective

The present study aimed to observe and discuss the effectiveness and safety of the UreTron single-probe ultrasonic intracorporeal lithotripter in ureteroscopic lithotripsy.

Methods

The clinical data of patients with unilateral solitary ureteral calculi treated with ureteroscopic lithotripsy who were hospitalized at the Department of Urology (West District) of Beijing Chaoyang Hospital between March 2016 and August 2020 were selected for retrospective analysis. The patients were divided into the UreTron group (group U) and holmium laser group (group H) according to the lithotripsy method adopted. The operation duration, length of hospital stay, stone clearance rate, proportion of patients requiring flexible ureteroscopy-assisted lithotripsy, and complications were compared between the groups.

Results

There was no statistical difference between the groups in terms of the general characteristics, operation duration, or length of hospital stay (P > 0.05). Regarding the stone clearance rate (group U=93.5%; group H=75%), proportion of patients requiring flexible ureteroscopy-assisted lithotripsy (group U=6.5%; group H=27.8%), and incidence of surgical complications (group U=1 case; group H=9 cases), group U was superior to group H, and the differences between the groups were statistically significant (P < 0.05). However, the differences in other complications (cardiocerebral complications and lower extremity thrombosis) were not statistically significant between the groups (P > 0.05).

Conclusion

The UreTron system is a new lithotripsy apparatus that is safe and effective for ureteroscopic lithotripsy and has certain advantages in terms of the stone clearance rate, proportion of patients requiring flexible ureteroscopy-assisted lithotripsy, and surgical complications, making it worthy of clinical application.

15 and 30 W Holmium:YAG Laser Lithotriptor in Ureteroscopic Lithotripsy: Which One Is More Effective and Safe?

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.

Comparison of mean operative time in patients undergoing Ho: YAG laser lithotripsy and pneumatic lithotripsy in ureterorenoscopy for ureteric calculus

Objective

To compare the mean operative time (MOT) in patients undergoing Ho: YAG laser lithotripsy (LL) and pneumatic lithotripsy (PL) for ureteric stones.

Methods

This randomized study was conducted at Armed Forces Institute of Urology (AFIU) Rawalpindi, Pakistan from July 2016 to November 2018. Non probability consecutive sampling technique utilized to enroll 60 patients of both gender aged 18-60 years, having ureteric calculus ≤1.5cm. Randomization was done into group I (LL) and II (PL) via computer generated number tables. Six Consultant Urologists performed surgeries under spinal anesthesia utilizing Swiss Lithoclast^® Master (EMS⁺ S.A. Switzerland) in group II and holmium laser fiber (365μm, 8-10Hz, 9.6-16W, 2100nm wavelength) in group I respectively. MOT was noted from insertion of cystoscope till removal out of meatus. Data obtained was analyzed through IBM SPSS 24.0.

Results

Analysis involved 60 patients (30 each group) having similar baseline characteristics (age, gender, laterality, location). There was statistically significant different MOT between LL & PL (25.48±6.99 vs 34.83± 7.47 minutes, p < 0.001). Data stratification with respect to age, gender, laterality and stone location revealed similar trend. Lithotripsy technique significantly affected MOT (p < 0.001) on Multiple Linear Regression Analysis.

Conclusions

Ho: YAG LL is an efficient technique when compared with PL in terms of MOT for ureteric stones.

Diagnosis accuracy of PCA3 level in patients with prostate cancer: a systematic review with meta-analysis

Objective:

This study aims to design a novel semirigid ureterorenoscope with irrigation and vacuum suction system and a modified ureteral access sheath (UAS) named Sotn ureterorenoscope^® (Sotn=ShuoTong Medical Company) to overcome the deficiencies of the current procedure and to improve the efficiency and safety of using Sotn ureterorenoscope^® for treatment of upper urinary calculi.

Materials and Methods:

Fifty-eight patients, comprising 31 males and 27 females, were evaluated. The medical records of 58 patients with upper urinary calculi treated with Sotn ureterorenoscope^® from March 2015 to June 2017 were retrospectively reviewed at the Second Affiliate Hospital of Guangzhou University of Chinese Medicine in China. The primary outcome was stone-free rate (SFR) assessed by computed tomography on the 1st day and one month after treatment. The secondary outcome was postoperative complication rate.

Results:

The mean and SD of operative duration was 48.5 (10.4) min, and the mean and SD of stone size was 15.6 (5.6) mm. The primary overall SFR was 89.7% (52/58) and 100% at 1 month follow-up. Complication, which was Clavien I (minor fever managed by antipyretic therapy), was detected in 1.7% (1/58) of the patients.

Conclusions:

Sotn ureterorenoscope^® is technically feasible, efficacious and safe for treatment of upper urinary calculi because of its advantages of high SFR and low complication rates.

Association between ureteric stent dwell time and urinary tract infection

BACKGROUND

Ureteric stone obstruction commonly presents to the emergency department, with definitive management often involving ureteroscopy and laser lithotripsy. Insertion of a ureteric stent prior to staged lithotripsy is commonly performed in the public healthcare system. Foreign bodies in the urinary tract are also known to increase urinary tract infection (UTI) risk. This study aims to evaluate the association between stent dwell time and UTI prior to lithotripsy.

METHODS

The medical records of all patients who were treated for ureteric stones with initial stent insertion and staged lithotripsy, from 1 January 2018 to 30 June 2019 at a single tertiary centre, by eight urologists were retrospectively reviewed. Demographic features, disease factors and urine culture data were collected and analysed.

RESULTS

Of the 172 patients (median age 56.7 years) identified, one-third had a positive pre-stent urine culture. Twenty-three percent had a positive pre-lithotripsy urine culture with 38% of females compared with 15% of males having a positive culture (P = 0.001). Only 4.3% of patients had a pre-lithotripsy UTI when the stent dwell time was less than 1 month compared with 26.2% when ureteric stents were in situ for longer than 1 month (P = 0.021). The correlation between ureteric stent dwell time and pre-lithotripsy UTI was not linear. Patient comorbidities, stone size, burden and location were not statistically correlated to pre-lithotripsy UTI.

CONCLUSION

In delayed two-staged surgical management of acute urolithiasis, optimal ureteric stent dwell time is less than 1 month to reduce pre-lithotripsy UTI. Female gender is an independent risk factor for pre-lithotripsy UTI.

Pneumatic vs laser lithotripsy for mid-ureteric stones: Clinical and cost effectiveness results of a prospective trial in a developing country

Objective

To compare the management of large ureteric stones (>10 mm) with ureterorenoscopy (URS) and laser or pneumatic lithotripsy, and their associated costs.

Patients and methods

Our prospective study followed the tenets of the Declaration of Helsinki and included 101 patients with large mid-ureteric stones eligible for URS and lithotripsy, and was conducted between January 2018 and August 2019. Patients were randomly divided into two groups: Group 1 had laser lithotripsy, while the Group 2 had lithotripsy using a pneumatic energy source.

Results

Operative time was significantly longer in cases using pneumatic lithotripsy (P < 0.001). The stone-free rate (SFR) on the first postoperative day was 94% and 92.5% for laser and pneumatic lithotripsy respectively, and there were no statistically significant differences in terms of early (day 1) or late (day 30) SFRs between the groups. Complications were classified according to the Clavien–Dindo Grading System, all complications were Grade <III, with no statistically significant difference between the groups (P = 0.742). The use of pneumatic lithotripsy had lower treatment costs. The number of auxiliary procedures required to reach a stone-free status was statistically equivalent in both groups.

Conclusion

The type of lithotripsy did not affect the SFR or complications. However, laser lithotripsy was much more expensive than pneumatic lithotripsy.

Abbreviations

KUB: plain abdominal radiograph of the kidneys, ureters and bladder; SFR: stone-free rate; SWL: shockwave lithotripsy; URS: Ureterorenoscopy; US: ultrasonography

Laser Versus Pneumatic Lithotripsy With Semi-Rigid Ureteroscope; A Comparative Randomized Study

Introduction: Ureteral stones are among the most common disorders in the urologic field. Miniaturization of endoscopic devices in urology and extracorporeal shock wave lithotripsy (ESWL) has revolutionized the management of ureteral stones. The aim of this study was to compare the efficacy and results of laser versus pneumatic lithotripsy (PL) with semi-rigid ureteroscope in a randomized prospective clinical trial in removing stones. Methods: 117 adult patients underwent transurethral lithotripsy (TUL) in a single academic center and by a single surgeon. The patients were randomized in 2 groups: In group 1, 58 patients with ureteral stones underwent ureteroscopy and stone fragmentation was done by Ho: YAG laser lithotripsy (LL) and in group 2, 59 patients underwent PL (Swiss LithoClast) by using the same ureteroscope. Results: Mean age was 41.77 years and 41.1years in group one and 2 respectively (P=0.79), there was no significant difference in male to female ratio and mean stone in both groups. The success rate for stone clearance was 79.31% and 77.96% in group 1 and 2 respectively (P=0.52). No difference between complications was seen in both groups, but the duration of operations was different (significantly lower in group 2). Conclusion: In both techniques, acceptable results were achieved. We have found a significant statistical difference in duration of operation between our results (P=0.001) and similar studies, while this was shorter in the pneumatic group in our study, it was longer in other similar ones. This might be a result of more experience in working with PL in our center.

Risk factors for ureteroscopic lithotripsy: a case-control study and analysis of 385 cases of holmium laser ureterolithotripsy

Introduction

Ureteroscopic lithotripsy has become the first choice for the treatment of middle and lower ureteral stones, but it still has a certain rate of surgical failure. Here we aimed to determine the factors that may affect the success rate of holmium laser ureterolithotripsy (HLU) and provide the basis and guidance for its future use.

Aim

To evaluate the risk factors for HLU failure.

Material and methods

The clinical data of 385 patients undergoing holmium laser ureterolithotripsy from 2009 to 2012 were retrospectively reviewed to analyze the impact of gender, age, stone side, stone size, stone location, stone number, degree of hydronephrosis, stone impaction, previous extracorporeal shock lithotripsy (ESWL), and associated urinary tract infection (UTI) on the success or failure of surgery.

Results

Surgical success was achieved in 338 (87.8%) patients versus surgical failure in 47 (12.2%) patients. Univariate analysis revealed that the degree of hydronephrosis (p = 0.024), stone impaction (p = 0.003), stone location (p = 0.012), and previous ESWL (p = 0.037) were risk factors for surgical failure. Multivariate logistic regression revealed that stone impaction (odds ratio (OR) = 2.66; p = 0.018) and stone location (OR = 2.11; p = 0.013) were significantly associated with surgical failure. Since some cases of ureterostenosis developed postoperatively, we continued follow-up. The patients had the stent for a year and underwent regular follow-up checks until 5 years. No cases of ureterostenosis recurred.

Conclusions

Ureteroscopic lithotripsy is a safe procedure with few complications. Stone impaction and proximal location are the risk factors for its failure.

Efficacy and safety of laparoscopic holmium laser lithotripsy in the treatment of complicated biliary calculus: A PRISMA-compliant systematic reviews and meta-analysis

BACKGROUD

The aim of this study was to assess the efficacy and safety of laparoscopic holmium laser lithotripsy (LHLL) in the treatment of complicated biliary calculus.

METHODS

We systematically searched the electronic database (PubMed, EMBASE, Cochrane library, Web of science, and Chinese Biomedical Literature Database) up to May 2018 to identify case-controlled studies that compared LHLL with laparoscopic bile duct exploration (LBDE) for complicated biliary calculus.

RESULTS

Five case-controlled studies were included, with 541 patients (273 in the LHLL group and 268 in the LBDE group). Compared with LBDE, LHLL was associated with shorter operative time (weighted mean difference [WMD] = -40.04, P < .001) and lower estimated blood loss (EBL) (WMD = -56.42, P < .001), lesser duration of hospitalization (WMD = -3.93, P < .001) and lower rate of residual stone (OR = 0.13, P < .001). There was no statistically significant differences in bile leakage (OR = 0.48, P = .23) and hemobilia (OR = 0.49, 0.41).

CONCLUSION

Current evidence suggests that the efficacy of LHLL is superior to that of LBDE but they are similarly safe for the treatment of complicated biliary calculus. Limited by the quantity and quality of the studies included, these conclusions need to be verified by more high-quality studies.

Moses technology in a stone simulator

INTRODUCTION

The objective of this study was to compare fragmentation efficiency of the conventional regular mode of holmium laser to the Moses contact mode on a stone simulator.

METHODS

The Lumenis^® Pulse^TM P120 H holmium laser system, together with Moses D/F/L fibers were used to compare regular mode with Moses contact mode in a stone simulator model using flexible ureteroscopy with artificial stones. Efficiency of laser lithotripsy was measured by procedural time. Degree of stone retropulsion was also compared between regular and Moses modes using a Likert scale from 0 (no retropulsion) to 3 (maximum retropulsion).

RESULTS

Using the stone simulator model, a significant reduction in stone retropulsion was noticed when comparing regular mode to the Moses contact mode (mean Grade 2.5 vs. Grade 1; p<0.01). When compared with the regular mode, the Moses contact mode was associated with significantly shorter procedural time during fragmentation (13.9 vs. 9.1 minutes; p≤0.01) and dusting (9.3 vs. 7.1 minutes; p≤0.01). In addition, when compared with the regular mode, the laser pedal was pressed significantly less often with the Moses mode during fragmentation (86 vs. 43 times; p<0.01) and dusting (50 vs. 26 times; p<0.01). Moses contact mode was associated with significantly higher percentage of lasing vs. pausing when compared with the regular mode for both fragmentation (0.8 J/10 Hz) and pulverization (0.4 J/50 Hz) settings (both p<0.05).

CONCLUSIONS

Using the stone simulator setup, Moses technology was associated with more efficient laser lithotripsy (shorter operative time) due to significantly reduced stone retropulsion.

The Effect of Comprehensive Care on the Patients Received Minimally Invasive Percutaneous Nephrolithotomy

BACKGROUND

We analyzed the effect of comprehensive care on the patients who received minimally invasive percutaneous nephrolithotomy (MPCNL).

METHODS

Patients hospitalized from 2013-2014 in Zhumadian Central Hospital (n=124) were enrolled and divided into two groups on random basis. The control group was treated with routine nursing model while the observation group was given comprehensive care additionally. The surgery time, degree of comfort, complications and successful cases, hospitalization time, sleep quality, nursing satisfaction and changes of systolic pressure, pulse and respiratory at different time were observed and analyzed.

RESULTS

The surgery time of the control group was significantly longer than that of observation group (P<0.05). The observation group felt more comfortable and showed more significant successful cases than the control group. Moreover, the hospitalization time were significantly reduced in observation group when compared with control group (P<0.05). The sleep quality of the observation group was significantly better than that of the control group (P<0.05). Before anesthesia, diastolic blood pressure, systolic blood pressure, pulse and respiration were not significantly different between the two groups. The diastolic blood pressure, systolic blood pressure, pulse and respiration after anesthesia, intraoperative 30 min, postoperative 30 min and other moments were significantly different. The incidence of complications in the control group was significantly higher than that in the observation group. The nursing satisfaction of the observation group was significantly higher than that of the control group.

CONCLUSION

The comprehensive care on the patients undergoing MPCNL was effective, and it can dramatically shorten surgery time, improve the success rate, improve the sleep quality of patients, keep life sign stable and minimize the complications.

Use of the Moses Technology to Improve Holmium Laser Lithotripsy Outcomes: A Preclinical Study

Objective: To evaluate in vitro and in vivo effects of Moses technology in Holmium laser and to compare it with the Regular mode in terms of lithotripsy efficiency and laser-tissue interactions.

Methods: The Lumenis^® Pulse™ P120H holmium laser system together with Moses D/F/L fibers were used to compare the Regular mode with the Moses modes in stone retropulsion by using a high-speed camera, and stone ablation efficiency. In addition, a porcine ureteroscopy model was used to assess stone fragmentation and dusting as well as laser-tissue interaction with the ureteral wall.

Results: After a laser pulse, in vitro stone displacement experiments showed a significant reduction in retropulsion when using the Moses mode. The stone movement was reduced by 50 times at 0.8 J and 10 Hz (p < 0.01). The pronounced reduction of retropulsion in the Moses mode was clearly observed during fragmentation setting (high energy) and dusting (low energy, high Hz). In addition, stone fragmentation tests showed that the Moses modes resulted in a significantly higher ablation volume when compared with the Regular mode (160% higher; p < 0.001). In vivo assessment also supported the reduction in retropulsion when treating stones in the porcine kidney. Histological analysis of the porcine ureter after direct lasing in the Moses mode suggested less damage than in the Regular mode.

Conclusions: The Moses technology resulted in more efficient laser lithotripsy, in addition to significantly reduced stone retropulsion, and displayed a margin of safety that may result in a shorter procedural time and safer lithotripsy.

LABEL procedure: Laser-Assisted Bile duct Exploration by Laparoendoscopy for choledocholithiasis: improving surgical outcomes and reducing technical failure

BACKGROUND

Laparoscopic bile duct exploration (LBDE) is recommended in current treatment guidelines for the management of choledocholithiasis with gallbladder in situ. Failure of this technique is common as a consequence of large or impacted common bile duct (CBD) stones. In this series, we present our experience in using holmium laser lithotripsy as an adjunct to LBDE for the treatment of choledocholithiasis.

METHODS

Between 2014 and 2016, eighteen laparoscopic bile duct explorations utilising holmium laser lithotripsy were performed after failure of standard retrieval techniques.

RESULTS

Choledocholithiasis was successfully treated in 18 patients using laparoscopic holmium laser lithotripsy (transcystically in 14 patients). There was one failure where a CBD stricture prevented the scope reaching the stone. Two medical complications were recorded (Clavien-Dindo I and II). There were no mortalities or re-interventions.

CONCLUSIONS

LABEL technique is a successful and safe method to enhance LBDE in cases of impacted or large stones. In our experience, this approach increases the feasibility of the transcystic stone retrieval and may reduce overall operative time.

Fluoroscopy free flexible ureteroscopy with holmium: Yttrium-aluminium-garnet laser lithotripsy for removal of renal calculi

Objective

To evaluate the feasibility of access sheath insertion and ureteric stent placement without image guidance in flexible ureteroscopic lithotripsy with holmium:yttrium-aluminium-garnet laser for renal stones.

Patients and methods

Between March 2014 and October 2015, 80 patients with renal stones treated with flexible ureteroscopic laser lithotripsy were evaluated. Indications for surgery were renal obstruction, failed shockwave lithotripsy (SWL), stones in polycystic kidneys, and mal-rotated kidneys. A 6.5-F Cobra flexible ureteroscope was used in all cases with an access sheath of 12 F, 35/45 cm in length. Fluoroscopy was not intended for use in all cases and postoperative JJ stenting was optional. The perioperative complications were listed and the collected data were analysed.

Results

The study included 80 patients (66 male, 14 female), with a mean (SD; range) age of 48.2 (8; 28–54) years and a stone burden of 13 (3.5; range 6–23) mm. In all, 26 patients had a stone burden of >15 mm and 48 patients had lower calyceal stones. The mean (SD; range) operative time was 71.5 (20; 25–130) min. Overall, 76 (95%) access sheath insertions were performed successfully without the use of fluoroscopy. JJ stenting was used in 22 patients (27.5%). The mean (SD; range) hospital stay was 10 (8.5; 10–36) h. After one session, a stone-free rate (SFR) of 87.5% was achieved (93.3% for stones of <15 mm). A single session was successful in 87.9% of cases with lower calyceal stones, with a SFR of 91.7% for post-SWL failure cases. The perioperative complication rate was 15%.

Conclusion

Access sheath insertion without fluoroscopic guidance is feasible. This technique reduces radiation exposure in patients requiring flexible ureteroscopy.

Is semirigid ureteroscopy sufficient in the treatment of proximal ureteral stones? When is combined therapy with flexible ureteroscopy needed?

The goals of this study were to examine cases of proximal ureteral stones in which semirigid or flexible ureteroscopes alone were insufficient for endoscopic treatment, requiring the combination of both. A total of 137 patients were retrospectively evaluated. Holmium laser was used as the energy source for stone fragmentation. Each operation was begun with a 6/7.5 Fr semirigid ureteroscope (URS), and continued with a 7.5 Fr flexible URS in those procedures that failed to reach the stone or push-up. Double J stents were inserted into those patients in whom the flexible URS failed. Shock wave lithotripsy (SWL) or a repeat ureteroscopy (after 2-4 weeks) was planned in those patients who were considered to be treated unsuccessfully. The demographic features of the patients, stone sizes, treatment outcomes, need for additional treatment, complications, and the results of the postoperative 1-month early follow-up were evaluated. The mean age of the patients (77 males and 60 females) was 38 ± 6.7 years old, the mean stone size was 12.3 ± 3.7 mm, and the number of patients with persistent hydronephrosis was 86 (62.8 %). A stone-free diagnosis was achieved in a total of 124 patients (90.5 %), using a semirigid URS in 80 patients and a flexible URS in 44 patients. Treatment using a flexible URS was administered in 38 patients (27.7 %) due to push-up, and in 6 patients (4.3 %) because of the failure to advance the semirigid URS into the ureter. The treatment failed in 13 patients (9.4 %) despite the use of both methods. Treatment using low-caliber semirigid ureteroscopy and a holmium laser is possible, regardless of the stone size, in female patients without hydronephrosis. However, the need for combined treatment with flexible ureteroscopy is increased in male patients with hydronephrosis.

The role of lasers in modern urology

INTRODUCTION

The functioning of modern urological departments and the high level of service they provide is possible through, among other things, the use of modern laser techniques.

MATERIAL AND METHODS

Open operations have been replaced by minimally invasive procedures, and classical surgical tools by advanced lasers. The search for new applications with lasers began as technology developed. Among many devices available, holmium, diode and thulium lasers are currently the most popular.

RESULTS

Depending on the wavelength, the absorption by water and hemoglobin and the depth of penetration, lasers can be used for coagulation, vaporization and enucleation. In many centres, after all the possibilities of pharmacological treatment have been exhausted, lasers are used as the primary treatment for patients with benign prostatic hyperplasia, with therapeutic results that are better than those obtained through open or endoscopic operations. The use of lasers in the treatment of urolithiasis, urinary strictures and bladder tumours has made treatment of older patients with multiple comorbidities safe, without further necessity to modify the anticoagulant drug treatment. Laser procedures are additionally less invasive, reduce hospitalization time and enable a shorter bladder catheterization time, sometimes even eliminating the need for bladder catherterization completely. Such procedures are also characterized by more stable outcomes and a lower number of reoperations.

CONCLUSIONS

There are also indications that with the increased competition among laser manufacturers, decreased purchase and maintenance costs, and increased operational safety, laser equipment will become mandatory and indispensable asset in all urology wards.