Low-power Holmium Research Articles

Minimalist Approach for HoLEP with A Low-Power Holmium Source: A Retrospective Study.

To assess the efficacy and safety of very low-power Holmium Laser Enucleation of the Prostate (HoLEP) on a 30-W holmium laser source. With the approval of the local ethics committee, we retrospectively analysed 60 patients treated with HoLEP. There were 30 patients in the low-power (LP) group and 30 patients in the very low-power (VLP) group. For the LP group, we used a 60-W holmium laser machine. Throughout the en bloc process, we used laser settings of 2 J and 20 Hz. We used a 30-W low-power holmium source in the VLP group. We used laser settings of 2 J and 10 Hz. All patients were operated on by an experienced surgeon. We evaluated the surgical parameters and practicality of the low-power laser vs. the very low-power laser. All patients underwent successful HoLEP in the very low-power group; it was not necessary to increase the output of the laser in any case. Mean preoperatively estimated prostate volume was 88.1 mL (range, 30-300 mL). Mean enucleation time and enucleation efficiency were 67.9 min (range, 25-150 min) and 0.99 gm/min (range, 0.8-1.8 gm/min), respectively. No patient required blood transfusion postoperatively. No stress urinary incontinence (SUI) was observed in the 3rd month postoperative follow-up. The use of a low-power laser source is encouraging for the learning curve of new surgeons who will begin HoLEP surgery; it can facilitate the adoption of HoLEP in developing countries, where the initial capital investment may be a major obstacle.

What Energy Crisis? The Use of Low-power Holmium Laser for Enucleation of the Prostate

What Energy Crisis? The Use of Low-power Holmium Laser for Enucleation of the Prostate

The Effect of High- and Low-power Holmium Laser Settings for Transurethral Lithotripsy in the Management of Adults with Ureteral Stone.

Since there is insufficient evidence to determine the best treatment of transurethral laser lithotripsy (TLL) in ureteral stones, this study compared the effectiveness and safety of TLL using high-power (HP) (100 W) and low-power (LP) (20 W) laser settings. All patients with maximally sized ureteral stones who were planned for transurethral holmium laser lithotripsy were enrolled in this open study. One of the two laser setting groups-LP or HP-was allocated to each alternate patient. Using IBM SPSS Statistics 24, the treatment groups were compared for operating time, intraoperative and postoperative problems (up to 1 year), and rates of stone-free recovery. Welch tests were employed to compare continuous data, whereas Fisher's exact or Chi-square tests were used to assess categorical variables. At P < 0.05, statistical significance was established. A total of 207 individuals were included and preoperative data were comparable between the two groups. The HP group had a considerably greater ablation rate and a significantly shorter procedure duration (42.61 ± 11.74 min) than the LP group (78.56 ± 25.91 min) ( P = 0.025). The Overactive Bladder Symptom Score and International Prostate Symptom Score were considerably higher in the HP group than in the LP group. Treatment effectiveness was considerably impacted by the location of the ureteral stone, according to univariate and multivariate logistic regression models. A HP laser setting of up to 100 W greatly shortens the duration of the process for treating ureteral stones without raising the risk of problems.

Observation and comparison of gas formation during holmium:YAG laser lithotripsy of cystine, uric acid, and calcium oxalate stones: a chromatographic and electron microscopic analysis.

The primary aim of the present in vitro study is to analyze the chemical content of the bubbles occurring during the fragmentation of cystine stones with both the high-power and low-power holmium:YAG (Ho:YAG) lasers. The secondary aim is to discuss their clinical importance. Three types of human renal calculi calcium oxalate monohydrate (COM), cystine, and uric acid were fragmented with both low-power and high-power Ho:YAG lasers in separate experimental setups at room temperature, during which time it was observed whether gas was produced. After laser lithotripsy, a cloudy white gas was obtained, after the fragmentation of cystine stones only. A qualitative gas content analysis was performed with a gas chromatography-mass spectrometry (GC-MS) device. The fragments in the aqueous cystine calculi setup were dried and taken to the laboratory to be examined by scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX) and X-ray diffraction analysis. No gas production was observed after fragmentation in the COM and uric acid stones. Free cystine, sulfur, thiophene, and hydrogen sulfide gas were produced by both low-power and high-power Ho:YAG laser lithotripsy of the cystine stones. In the SEM-EDX mapping analysis, a free cystine molecule containing 42.8% sulfur (S), 21% oxygen (O), 14.9% carbon (C), and 21% nitrogen (N) atoms was detected in the cystine stone experimental setup. The evidence obtained, which shows that hydrogen sulfide emerges in the gaseous environment during Ho:YAG laser fragmentation of cystine stones, indicates that caution is required to prevent the risk of in vivo production and toxicity.

MP23-09 COMPARISON OF LOW-POWER VS HIGH-POWER HOLMIUM LASERS IN PAEDIATRIC RIRS OUTCOMES

You have accessJournal of UrologyCME1 Apr 2023MP23-09 COMPARISON OF LOW-POWER VS HIGH-POWER HOLMIUM LASERS IN PAEDIATRIC RIRS OUTCOMES Ee Jean Lim, Esther García Rojo, Stefania Ferreti, Anna Bujons, Olivier Traxer, Danielle Castellani, Yesica Quiroz, Deepak Ragoori, Tanuj Paul Bhatia, Chandra Mohan Vaddi, Claudia Gatti, Khi Yung Fong, Yiloren Tanidir, Bhaskar Kumar Somani, Anil Shrestha, and Vineet Gauhar Ee Jean LimEe Jean Lim More articles by this author , Esther García RojoEsther García Rojo More articles by this author , Stefania FerretiStefania Ferreti More articles by this author , Anna BujonsAnna Bujons More articles by this author , Olivier TraxerOlivier Traxer More articles by this author , Danielle CastellaniDanielle Castellani More articles by this author , Yesica QuirozYesica Quiroz More articles by this author , Deepak RagooriDeepak Ragoori More articles by this author , Tanuj Paul BhatiaTanuj Paul Bhatia More articles by this author , Chandra Mohan VaddiChandra Mohan Vaddi More articles by this author , Claudia GattiClaudia Gatti More articles by this author , Khi Yung FongKhi Yung Fong More articles by this author , Yiloren TanidirYiloren Tanidir More articles by this author , Bhaskar Kumar SomaniBhaskar Kumar Somani More articles by this author , Anil ShresthaAnil Shrestha More articles by this author , and Vineet GauharVineet Gauhar More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003248.09AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: To compare the outcomes of using low power (up to 30 W) vs high power (up to 120 W) holmium lasers in paediatric retrograde intrarenal surgery (RIRS) and to analyse if the choice of scopes; lasering techniques and the use of access sheath have any influence on the final outcomes. METHODS: We performed a retrospective, multicentre study in a paediatric population (≤18 years of age), who underwent RIRS with holmium laser for treatment of kidney stones between January 2015 and December 2020. Patients were divided into two groups according to laser used: high power holmium laser and low power holmium laser. Clinical, perioperative variables and complications were analyzed. Outcomes were compared between groups using Student's T-test for continuous variables, and for categorical variables were used Chi-square and Fisher's exact test. A multivariable logistic regression analysis model was also performed. RESULTS: 314 patients from 9 centres were included. A high-power holmium laser was used in 97 patients, whereas 217 patients underwent low power holmium laser with a mean age of 10.01 and 9.54, respectively. Clinical and demographic variables were comparable between both groups, except for stone size where the low power group treated slightly larger stones (mean 11.11 mm vs 9.70 mm; p 0.018). In the high-power laser group, a reduction in surgical time was found (mean 64.29 min vs 75.27 min; p 0.018) with significantly higher SFR (mean 81.4% vs 59%; p<0.001) and faster operative time (mean 75.27 min vs 64.29 min; p 0.018). We found no statistical differences in complications rates but overall number of complications was higher in low-power holmium laser group. The multivariate logistic regression model also shows statistically significant results that the low-power holmium laser group has a lower SFR, especially in larger lithiasis (p=0.011or multiple stones, p<0.001). CONCLUSIONS: Our real world pediatric multicenter study favors high-power holmium laser and establishes is safety and efficacy in children. With innovations, it would be best adapted to provide the best possible SFR results in a single session for children without compromising safety. Source of Funding: NIL © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e309 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Ee Jean Lim More articles by this author Esther García Rojo More articles by this author Stefania Ferreti More articles by this author Anna Bujons More articles by this author Olivier Traxer More articles by this author Danielle Castellani More articles by this author Yesica Quiroz More articles by this author Deepak Ragoori More articles by this author Tanuj Paul Bhatia More articles by this author Chandra Mohan Vaddi More articles by this author Claudia Gatti More articles by this author Khi Yung Fong More articles by this author Yiloren Tanidir More articles by this author Bhaskar Kumar Somani More articles by this author Anil Shrestha More articles by this author Vineet Gauhar More articles by this author Expand All Advertisement PDF downloadLoading ...

Comparing Pediatric Ureteroscopy Outcomes with SuperPulsed Thulium Fiber Laser and Low-Power Holmium:YAG Laser.

The thulium fiber laser is a promising new lithoptripsy technology never before studied in the pediatric population. Our center adopted the first platform in North America, the SuperPulsed thulium fiber laser (SPTF). We aimed to compare outcomes in pediatric ureteroscopy using the SPTF to those using the gold standard, low-power holmium:yttrium-aluminum-garnet (Ho:YAG) laser. This is a retrospective, consecutive cohort study of unilateral ureteroscopy with laser lithotripsy performed in pediatric patients from 2016 to 2021 as an early adopter of the SPTF. Thirty-day complications and stone-free status, defined as the absence of a stone fragment on followup imaging within 90 days, were analyzed using logistic regression. Operative times were compared using linear regression. Propensity scores for use of SPTF were used in regression analyses to account for potential cohort imbalance. A total of 125 cases were performed in 109 pediatric patients: 93 with Ho:YAG and 32 with SPTF. No significant difference was noted in age (p=0.2), gender (p=0.6), stone burden (p >0.9) or stone location (p=0.1). The overall stone-free rate was 62%; 70% with SPTF and 59% with Ho:YAG. The odds of having a residual stone fragment were significantly lower with SPTF than with Ho:YAG (OR=0.39, 95% CI: 0.19-0.77, p=0.01). There was no significant difference in operative time (p=0.8). Seven (25%) complications were noted with SPTF and 19 (22%) with Ho:YAG (p=0.6). The SPTF laser was associated with a higher stone-free rate than the low-power Ho:YAG laser without compromising operative time and safety.

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.

Prediction models of low-power holmium laser effectiveness in renal stone lithotripsy during retrograde intrarenal surgery.

The objectives of this study are to develop prediction models for total laser energy (TLE) in order to infer surgical time and assist operative planning of intrarenal low-power Ho:YAG laser lithotripsy, and to predict the fragmented volume as well as the stone-free status (SFS). A retrospective review was performed, comprising all single surgeon standardized retrograde intrarenal surgery and low-power Ho:YAG laser lithotripsy at a tertiary care centre between October 2014 and September 2019. Automated measurement of stone volume and stone density (MSD), measured in Hounsfield units (HU), was employed in both pre- and post-operative non-contrast-enhanced computed tomography (NCCT), using a standardized technique on Osirix Lite® software. SFS was defined as complete absence of stone fragments, or fragments < 0.1cm on meticulous inspection at the end of the procedure, and residual stone burden < 0.0005 cm3 on postoperative NCCT at 3months. Statistical analysis was performed using the STATA® version 13.1 software for regression models. A p value < .05 was considered statistically significant. A total of 100 patients met the inclusion criteria, requiring a median of 22.3kJ/cm3 (13.4-36.0) and resulting in a SFS of 41% at 3months. In a multivariate analysis, according to stone composition, predicted TLE is equal: for uric acid (UA), 11.17 × volume(cm3) + 0.17 × MSD(HU) + 7.48kJ; for mixed stones, 11.17 × volume(cm3) + 0.17 × MSD(HU) + 6.26kJ; for calcium oxalate monohydrate (CaOM) stones, 11.17 × volume(cm3) + 0.17 × MSD(HU) + 1.14kJ; and for calcium phosphate (CaPh) stones 11.17 × volume(cm3) + 0.17 × MSD(HU) - 1.94kJ. Predicted fragmented volume is equal to 0.93 × volume(cm3) cm3. The significant predictors for SFS were UA stones, the presence of multiple stones, and lower TLE. In clinical practice, our models for intrarenal low-power Ho:YAG laser lithotripsy indicate that larger, denser, and UA stones are associated to higher TLE, and that single and UA stones are more commonly associated to SFS. Since higher TLE means longer operative time, when adjusting for laser parameters, our prediction models may help urologists plan surgeries more precisely based on stone characteristics, ultimately optimizing patients' treatment.

A prospective evaluation of high- and low-power holmium laser settings for transurethral lithotripsy in the management of adults with large bladder calculi

To prospectively investigate the efficacy and safety of high-power (100W) vs low-power (20W) laser settings for transurethral laser lithotripsy in the management large vesical calculi (> 4cm). All patients with vesical calculi > 4cm in the maximum dimension and scheduled for transurethral holmium laser lithotripsy were invited to participate in the study. Every alternate patient was treated with either the low- or high-power laser settings. We used a continuous irrigation resectoscope with laser bridge or a laser working element (Karl Storz) for laser lithotripsy of bladder stones. We compared the operative time, intra-operative/post-operative complications (up to 1year), and stone-free rates between the treatment groups using IBM SPSS Statistics 24 software. Comparisons between treatment groups for continuous variables were assessed using the Welch test, while categorical variables were compared with either the Chi-square or Fisher's exact test. A p value < 0.05 was considered statistically significant. Twenty patients with ten in each cohort were recruited. Preoperative data and mean bladder stone size were comparable in both groups. The duration of surgery was significantly reduced from 70.80 ± 25.28min in low-power cohort to 40.90 ± 15.01min in the high-power group (p = 0.005). There were no significant intra-operative complications in either group. All patients were stone-free following the procedure. High-power laser setting of up to 100W results in a significant reduction in duration of surgery without any increase in the complication rate for treatment of large bladder stones.

'Seven-step two-lobe' HoLEP: a modification to gain efficiency of the enucleation applying relatively low-power holmium laser devices.

In order to increase the efficiency of the low-power holmium laser enucleation of the prostate (LP-HoLEP), and introduce it as a standard surgery for BPH, we described a modified 'seven-step two-lobe' HoLEP (ST HoLEP) technique applying 60-W device in a stepwise manner. From July 2016 to August 2019, 120 patients who received LP-HoLEP at our hospital because of urinary tract symptoms caused by BPH were included in the study. The patients were assigned into two groups, 60 consecutive patients received modified ST HoLEP compared with another preexisting 60 consecutive patients who received the conventional three-lobe HoLEP (T HoLEP) before the technical modification. The clinical parameters, including patient characteristics, perioperative data, as well as voiding outcomes, and complications were evaluated after at least 3-month follow-up. The median enucleation efficiency of the ST HoLEP was 0.72gm/min, which was significantly higher than 0.62gm/min of the T HoLEP. Despite the preoperative IPSS was slightly higher in T HoLEP group, the other preoperative and perioperative data showed no statistical difference between the two groups. After ST HoLEP procedure, the urinary incontinence rate was continually improved at 1-week, 1-month, and 3-month follow-up which were 13.3%, 6.7%, and 1.7%, respectively. There was no significant difference in postoperative voiding outcomes and urinary continence results in 3-month follow-up. The ST HoLEP technique was proved to increase the efficiency which was benefit from minimizing the surgical incision, facilitating the single surgical plane identification and maintenance during the whole enucleation procedure.

Safety and efficacy assessment of low-power holmium laser enucleation of the prostate

Objective To assess the safety and efficacy of low-power holmium laser enucleation of the prostate (LP-HoLEP) for the treatment of benign prostate hyperplasia(BPH). Methods From July 2016 to June 2017, a total of 120 BPH patients in our hospital underwent LP-HoLEP(n=60) or TURP(n=60). The removal weight of proliferation, operation time, postoperative bladder irrigation time, hospital stay, postoperative maximum urinary flow rate Qmax, residual urine volume (RUV), IPSS and QOL were compared between two groups. Results All patients underwent successful HoLEP with the low-power setting. Compared with TURP groups, patients who underwent LP-HoLEP had more removal weight of proliferation, less operation time, less urinary tract infection occurrence rate, less postoperative bladder irrigation time and less hospital stay. These differences above were statistically significant(P 0.05). Conclusions LP-HoLEP is a safe and effective procedure for the treatment of BPH. Compared with HP-HPLEP, it is cost-effetive and worthy of clinical promotion. Key words: Prostatic Hyperplasia; Lasers, Solid-State; Prostatectomy

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.

High- vs Low-power Holmium Laser Lithotripsy: A Prospective, Randomized Study in Patients Undergoing Multitract Minipercutaneous Nephrolithotomy

To determine the efficacy and safety of high-power holmium: yttrium aluminum-garnet (Ho:YAG) laser lithotripsy for multitract modified minimally invasive percutaneous nephrolithotomy (MPCNL) in the treatment of patients with large staghorn renal calculi. A randomized, prospective study was conducted. Two-hundred seventy-three consecutive patients (291 renal units) with large staghorn renal calculi were randomized to undergo multitract MPCNL with 30-W low-power or 70-W high-power Ho:YAG laser lithotripsy. Both groups were compared in terms of perioperative findings and postoperative outcomes, including procedure time, stone-free rate, length of hospital stay, transfusion rates, renal function recovery, and other complications. The average patient age was 49.2 years (range 22-73) and mean stone size was 5.54±0.7 cm. The 2 groups had some comparable perioperative findings and outcome, including tracts required per operated renal unit (n), blood loss, postoperative fever, postoperative hospital stay, stone-free rate, and improvement of operated renal function. The operation time in the high-power group was significantly shorter than that in the low-power group (129.20±17.2 vs 105.18±14.2, P<.01). A combination of multitract MPCNL and high-power Ho:YAG laser lithotripsy can greatly decrease the operative time without increasing the intraoperative complications or delaying postoperative renal function recovery when compared with low-power Ho:YAG laser lithotripsy.

Low-power holmium:YAG laser urethrotomy for urethral stricture disease: Comparison of outcomes with the cold-knife technique

In this prospective randomized clinical trial, we aimed to evaluate the safety and efficacy of endourethrotomy with holmium:yttrium-aluminium-garnet (HO:YAG) laser and compare the outcomes with the conventional cold-knife urethrotomy. Fifty-one male patients with single, iatrogenic, annular strictures of the urethra were randomly divided into two groups; 21 patients who underwent direct-vision endoscopic urethrotomy with Ho:YAG laser (15 W; 1,200–1,400 mJ; 8–12 Hz) at 12 o’clock position (laser group) and 30 patients who underwent direct-vision endoscopic urethrotomy with cold-knife incision at 12 o’clock position (cold-knife group). The results obtained were analyzed and compared at 3 months, 6 months, 9 months, and 12 months postoperatively by clinical evaluation, uroflowmetry, and retrograde urethrographies. Variables were compared among groups using Fisher’s exact and Mann Whitney U tests. There were no differences between two groups in terms of patient age, preoperative Qmax value, stricture location, and length. Operative time was shorter in laser group (16.4 ± 8.04 minutes) when compared with cold-knife group (23.8 ± 5.47 minutes) ( p < 0.001). Recurrence-free rate at 3 months was similar between two groups ( p = 0.122). However, recurrence-free rates at 6 months, 9 months, and 12 months were significantly higher in laser group when compared with cold-knife group ( p values were 0.045, 0.027, and 0.04, respectively). No intra- or postoperative complications were encountered. Use of Ho:YAG laser in the management of urethral stricture disease is a safe and effective method. In addition, it provides shorter operative time and lower recurrence rate when compared with the conventional technique.

Comparison of Low-Power Laser and Ultrasound Litotripsy in the Management of Middle-Distal Ureteral Stones

To compare the success rates and complications of ultrasound and low-power Holmium laser-assisted ureteroscopy (URS) in managing middle-distal ureteral stones. We retrospectively analyzed the records of 90 patients with middle-distal ureteral stones who underwent ureteroscopic lithotripsy at our institution from May 2006 to April 2010. 45 patients were treated with ultrasound (mean size 6.7 mm), 45 patients with low-power Holmium laser (mean size 7.4 mm). The same ureteroscope (9.5/8ch rigid-Storz) was used to treat all the patients. Patients were monitored before the hospital discharge with abdominal radiograph and ultrasonography, and as outpatients after 3 months with abdominal radiograph, ultrasonography and urography in selected cases. We obtained a complete immediate fragmentation of stones in 27/45 (60%) patients with ultrasound, and in 36/45 (80%) patients after laser treatment. A proximal migration of stones was observed in 12/45 (26.8%) patients with ultrasound and 3/45 (6.6) with laser. We observed a ureteral perforation after laser treatment and no patient developed urosepsis. 6/45 (13.3%) patients who were treated with ultrasound underwent auxiliary therapy such as alkalizing therapy, 9/45 (20%) patients a second ureteroscopy, 9/45 (20%) a shockwave lithotripsy. No patient underwent an auxiliary shockwave treatment after laser, 6/45 (13.4%) patients underwent a second ureteroscopy. Operating time (20.33 vs 28.85 minutes) and hospitalization (3.6 vs 5.1 days) were shorter with laser if compared with ultrasound treatment. In our study the fragmentation rates of Holmium laser-assisted ureteroscopy were significantly better than with ultrasound in the middle-distal ureteral stones management. We did not have relevant complications using both procedures, and the need for auxiliary procedures was significantly less for Holmium laser-assisted ureteroscopy when compared with ultrasound.

Percutaneous Nephrolithotomy for Proximal Ureteral Calculi with Severe Hydronephrosis: Assessment of Different Lithotriptors

We compared the efficacy and safety of percutaneous nephrolithotomy (PCNL) with different intracorporeal lithotriptors for proximal ureteral stones in patients with severe hydronephrosis. We retrospectively analyzed the records of 192 patients with proximal ureteral calculi and severe hydronephrosis who underwent PCNL between February 2003 and December 2007. Calculi were fragmented with a pneumatic lithotriptor in 44 patients (group 1), Swiss Lithoclast Master in 54 (group 2), low-power holmium:yttrium-aluminum-garnet (YAG) laser in 56 (group 3) and high-power holmium:YAG laser in 38 (group 4). Patients were assessed about 12 months postoperatively with intravenous urography and ultrasonography for late complications. Stone size, operative time, stone-free rate, and follow-up were analyzed in each group. Mean stone size for different groups were 16.2 +/- 2.8 mm, 16.6 +/- 2.1 mm, 16.0 +/- 2.7 mm, and 16.4 +/- 1.1 mm, respectively. Average operative time for different groups were 118 +/- 17 minutes, 81 +/- 10 minutes, 85 +/- 14 minutes, 110 +/- 16 minutes, respectively. Group 2 and group 3 showed superior outcomes of shorter operative time (P = 0.000). The overall stone-free rate was 86.5%. As stratified by lithotriptors, the stone-free rate was 81.8% in group 1, 92.9% in group 2, 88.9% in group 3, and 78.9% in group 4 (P = 0.190). No significant difference was found among the groups in terms of blood loss and postoperative hospital stay. Repeated PCNL or shockwave lithotripsy was necessary as an auxiliary procedure in 26 patients. The overall complication rate was 18.2%; most complications were minor and insignificant. During the follow-up, ureteral stricture developed in 10 patients and new renal stones developed in 4 patients. PCNL combined with Swiss Lithoclast Master or low-power holmium:YAG laser is the preferred endourologic modality for the management of proximal ureteral calculi in patients with severe hydronephrosis.

Pediatric Ureteroscopic Management of Intrarenal Calculi

Data addressing ureteroscopic management of intrarenal calculi in prepubertal children are limited. We reviewed our experience from January 2002 through December 2007. We retrospectively reviewed ureteroscopic procedures for intrarenal calculi in children younger than 14 years. Stone-free status was determined with postoperative imaging. Multiple logistic regression analysis was used to assess the influence of preoperative factors on initial stone-free status and the need for additional procedures. Intrarenal calculi were managed ureteroscopically in 52 kidneys in 50 children with a mean age of 7.9 years (range 1.2 to 13.6). Mean stone size was 8 mm (range 1 to 16). Stone-free rate after a single ureteroscopic procedure was 50% (25 of 50 patients) on initial postoperative imaging and 58% (29 of 50) with extended followup. Initial stone-free status was dependent on preoperative stone size (p = 0.005) but not stone location. Additional stone procedures were required in 18 upper tracts. Younger patient age (p = 0.04) and larger preoperative stone size (p = 0.002) were associated with the need for additional procedures. Additional procedures were required in more than half of the stones 6 mm or larger but in no stone smaller than 6 mm. Ureteroscopy is a safe method for the treatment of intrarenal calculi in the prepubertal population. Our ureteroscopic stone-free rate for intrarenal stones is lower than that reported for ureteral stones. Parents should be informed that additional procedures will likely be required, especially in younger patients and those with stones larger than 6 mm.

Low-Power Holmium:YAG Laser Urethrotomy for Treatment of Urethral Strictures: Functional Outcome and Quality of Life

To evaluate the efficacy of endourethrotomy with the holmium:YAG laser as a minimally invasive treatment for urethral stricture. Between January 2002 and January 2004, 32 male patients with symptomatic urethral strictures (8 bulbar, 9 penile, 9 combined) were treated with Ho:YAG-laser urethrotomy in our department. The stricture was iatrogenic in 60% (N = 18), inflammatory in 16.6% (N = 5), traumatic in 13.3% (N = 4), and idiopathic in 7% (N = 3). The stricture was incised under vision at the 12 o'clock location or the site of maximum scar tissue or narrowing in asymmetric strictures. Laser energy was set on 1200 to 1400 mJ with a frequency of 10 to 13 Hz. Postoperatively, drainage of the bladder was performed for 4 days using a 18F silicone catheter. Triamcinolone was instilled intraurethrally after removal of the catheter in all patients. Patients were followed up by mailed questionnaire, including International Prostate Symptom Score and quality of life. Retrograde endoscopic Ho:YAG laser urethrotomy could be performed in all 32 patients. Most patients (22; 68.7%) did not need any reintervention. Ten patients developed recurrent strictures that were treated by another laser urethrotomy in 4 patients (12.5%), while 6 patients (18.7%) needed open urethroplasty with buccal mucosa. Including 2 patients treated with repeat laser urethrotomy, 24 patients (75%) were considered successful after a mean follow-up of 27 months (range 13-38 months). No intraoperative complications were encountered, although in 5% of patients, a urinary-tract infection was diagnosed postoperatively. No gross hematuria occurred. The Ho:YAG laser urethrotomy is a safe and effective minimally invasive therapeutic modality for urethral stricture with results comparable to those of conventional urethrotomy. Further data from long-time follow-up are necessary to compare the success rate with that of conventional urethrotomy and urethroplasty. Nevertheless, the Ho:YAG laser urethrotomy might at least be an alternative to urethroplasty in patients with high comorbidity who are not suitable for open reconstruction.

Endoscopic management of urologic disease with the holmium laser.

The efficiency and safety profile of the holmium laser have made this tool a versatile multipurpose instrument for use in the endoscopic treatment of a wide variety of urologic disorders. Herein are reviewed holmium laser physics and current endourologic applications, as well as the performance of new low-power holmium lasers.