Holmium Laser Energy Research Articles

Comparison of Moses laser and Raykeen laser in patients with impacted upper ureteral stone undergoing flexible ureteroscopic holmium laser lithotripsy

BackgroundTo compare the operative effect and clinical efficacy of the Moses laser mode and the Raykeen holmium laser energy platform powder mode under flexible ureteroscopic lithotripsy in patients with impacted upper ureteral stones.MethodsFrom March 2022 to September 2022, 72 patients were divided into a Moses laser group and a Raykeen laser group according to surgical method, with 36 patients in each group. CT and ureteroscopy confirmed that all patients had isolated impacted upper ureteral stones. The stone volume (mm3), stone density (Hu) and severity of hydronephrosis were measured by CT. Postoperative complications were evaluated using the Clavien–Dindo score.ResultsThere were no complications of ureteral stenosis related to the laser treatment. The operative time and lithotripsy time were lower in the Moses laser group than in the Raykeen laser group (P < 0.05). The stone-free survival rate did not differ significantly between the two groups (P = 0.722). Stone volume was found to be positively correlated with laser energy and lithotripsy time in both groups (P < 0.01). There was no significant correlation between laser energy and lithotripsy time or ureteral stone density (Hu) in the Moses laser group (P > 0.05) or the Raykeen laser group (P > 0.05).ConclusionsThe contact mode of Moses technology and the powder mode of Raykeen laser lithotripsy can be used for the ablation of a single impacted upper ureteral stone. The ablation speed was related to the stone volume and the severity of polyp hyperplasia, not the stone density. We recommend the use of the powdered mode as a therapeutic measure for the treatment of impacted upper ureteral stones in flexible ureteroscopic lithotripsy.

Laser operator duty cycle effect on temperature and thermal dose: in-vitro study.

High-power laser lithotripsy can elevate temperature within the urinary collecting system and increase risk of thermal injury. Temperature elevation is dependent on power settings and operator duty cycle (ODC)-the percentage of time the laser pedal is depressed. The objective of this study was to quantify temperature and thermal dose resulting from laser activation at different ODC in an in-vitro model. Holmium laser energy (1800J) was delivered at 30W (0.5J × 60Hz) to a fluid filled glass bulb. Room temperature irrigation was applied at 8ml/min. ODC was evaluated in 10% increments from 50-100%. Bulb fluid temperature was recorded and thermal dose calculated. Time to reach threshold of thermal injury and maximal allowable energy were also determined at each ODC. Upon laser activation, there was an immediate rise in fluid temperature with a "saw-tooth" oscillation superimposed on the curves for 50-90% ODC corresponding to periodic activation of the laser. Higher ODC resulted in greater maximum temperature and thermal dose, with ODC ≥ 70% exceeding threshold. Use of 50% compared to 60% ODC resulted in a tenfold increase in time required to reach threshold of thermal injury and an eightfold increase in maximal allowable energy. Laser activation at higher ODC produced greater fluid temperature and thermal dose. Time to threshold of thermal injury and maximal allowable energy were dramatically higher for 50% compared to 60% ODC at high-power settings. Proper management of laser ODC can enhance patient safety and optimize stone treatment.

The use of 14/16Fr ureter access sheath for safe and effective management of large upper ureteral calculi.

To evaluate the effectiveness of ureteroscopic lithotripsy for the management of large proximal ureteral stones > 10mm using 14/16 Fr ureteral access sheath (UAS). Patients' data from prospective database undergoing ureteroscopic laser lithotripsy with a use of 14/16Fr UAS were collected. All patients were pre-stented prior to the procedure. The fragmentation was performed with a semi-rigid ureteroscope using holmium laser energy with a power setting of 35W (frequency-35Hz; energy-1J). Follow-up was scheduled at 4 weeks and 3 months postoperatively. In total 78 patients, 43 males and 35 females, were included in the study. The mean age of the patients was 59.5 ± 13.3 with a mean maximal stone diameter of 13.4 ± 2.1. The mean operative time was 35.7 ± 9.7 and the mean hospital stay was 2 ± 0.7days. The primary SFR at 4 weeks was 73 patients (93.6%), while all 78 patients (100%) were stone free at 3-month follow-up, 2 of the patients receiving additional treatment. In total, 8 (10.2%) patients experienced Grade II complications. Intraoperative ureteral lesions were observed in 41 (52.6%) cases. Out of them 31 patients (39.7%) developed Grade 1, 8 patients (10.3%) Grade 2 and only 3 patients (2.6%) Grade 3 lesions. The use of 14/16Fr ureteral access sheath on pre-stented patients was associated with successful outcomes. A high stone-free rate of 93.6% was achieved at 4-week follow-up. The procedure was not associated with increased rate of postoperative complications and intraoperative ureteral injury.

A study effecting of the Power settings for Holmium - YAG laser on lithotripsy time Intra corporeal

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.

The combination of waterjet ablation (Aquabeam®) and holmium laser power for treatment of symptomatic benign prostatic hyperplasia: early functional results.

IntroductionThe aim of this study was to assess the short-term functional outcomes and the efficacy of hemostasis performed with holmium laser performed following prostatic hydroablation with the Aquabeam® system.Material and methodsBetween June 2019 and July 2020, 53 consecutive patients underwent Aquabeam® with our modified hemostasis approach with holmium laser. The following standard preoperative assessments were retrospectively recorded: prostate volume; International Prostate Symptom Score (IPSS) and Quality of Life (IPSS-QoL); uroflowmetry including Qmax and post void residual volume (PVR).ResultsFifty-three patients consecutively underwent aquablation and holmium laser hemostasis. Median age at surgery, median prostate-specific antigen (PSA) and median prostate volume were 62 years (IQR: 57–66), 2.95 ng/ml (IQR: 1.6–4.8) and 55 ml (IQR: 43–65), respectively.Median operative time was 60 minutes (IQR: 40–80). Median catheterization time and length of hospital stay were 2 days (IQR: 1–3) for both parameters. The median hemoglobin decrease between the preoperative values and those assessed on the second day was equal to 1.25 g/dl (IQR: 0.7–1.85).Continence rate was 100% at catheter removal. Thirty-six patients (72%) reported anterograde ejaculation preservation. IPSS (6, 3–21) and Qmax (19, 9–26) changed dramatically between baseline and 3 months follow-up.ConclusionsThe combination of Aquabeam® and holmium laser energy for hemostasis is a safe, reproducible technique to relieve moderate lower urinary tract symptoms (LUTS) in men with benign prostatic hyperplasia (BPH) while preserving ejaculation in younger and sexually active individuals. The short-term results showed a lower rate of complications; the encouraging functional results confirm that this can be a valid surgical approach for treatment of BPH.

Оценка скорости фрагментации мочевых камней при контактной литотрипсии гольмиевым лазером

For rational planning of laser lithotripsy tactics, determination of pulse settings and laser modes, considering patients condition, stone size and composition as well as for more rationale planning of operation theatre loading and the use of high-technology equipment the knowledge of the time required for complete stone fragmentation is needed. It is still assessed subjectively base on the urologists own experience. To determine the specific value of urinary stones mass decrease in order to evaluate exact time for complete fragmentation during holmium laser lithotripsy. Fragmentation time values were derived from in vitro studies in which lithotripsy using holmium laser was compared to other lithotriptors types, as well as our own results of time and energy level measurement during urinary stones fragmentation in vivo were used. As baseline data for estimating of the urinary stones destruction using holmium laser lithotripsy we suggest to use not stone volume but its mass which combine in some extent the volume and density. To take into account energy level for stone fragmentation it is suggested to introduce new value, the specific decrease of the stone mass per unit of laser energy (mg/J). It is established that such a value is a constant for a given laser type and fiber size. This value is calculated using stone dimensions, its density in HU and the total laser energy delivered during complete fragmentation. Based on experimental data it is estimated that specific decrease of the stone mass per unit of holmium laser energy during fragmentation in vitro of BegoStone is 0.442+/-0,083 mg/J (p=0.05). This value, measured in real conditions in vivo during urinary stones lithotripsy using holmium laser Triple ("Medoptotech") with 600 m fiber is 0.401+/-0.12 mg/J (=0.05). The use of specific decrease of the stone mass per unit of the laser energy during lithotripsy allows to assess complete fragmentation time of the urinary stones, based on their dimensions and density in HU. The absolute error in estimating of stone fragmentation time does not exceed several minutes, which is quite acceptable for calculating the total time of using high-technologic equipment and operative time.

MP83-08 EN-BLOC EXCISION OF UROTHELIAL BLADDER CANCERS BY HOLMIUM LASER: A FEASIBILITY STUDY.

You have accessJournal of UrologyBladder Cancer: Non-invasive II1 Apr 2018MP83-08 EN-BLOC EXCISION OF UROTHELIAL BLADDER CANCERS BY HOLMIUM LASER: A FEASIBILITY STUDY. Pankaj Maheshwari and Saurabh Patil Pankaj MaheshwariPankaj Maheshwari More articles by this author and Saurabh PatilSaurabh Patil More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2018.02.2756AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES En-bloc excision of bladder tumors may improve staging quality and perioperative morbidity and influence tumor recurrence. This study was designed to evaluate the feasibility, safety and efficacy of en-bloc holmium laser excision of bladder tumors. METHODS Holmium laser excision of bladder tumor was performed in 40 consecutive patients with a pre-op diagnosis of superficial bladder tumor. Transurethral en-bloc excision with a small mucosal margin was performed with holmium laser energy (1.5-2.0 Joules with 40-50 Hz frequency). Tumor base biopsy was taken either by holmium laser or by punch biopsy forceps. Staging quality was measured by presence of detrusor muscle in the pathology specimen. Various perioperative parameters like bleeding and need for transfusion were analyzed. RESULTS The patient's age ranged from 13 to 92 years with most patients in the 3rd and 4th decade. The tumor size varied from 1.5 cm to 9 cm. Single tumor was seen in 18 patients while others had multiple lesions (2-7 tumors). En-bloc excision was successfully achieved in all patients. The median operation duration was 20 min. Three-way catheter with irrigation was utilized in 16 patients with average postoperative irrigation of less than 1 day in these patients. The average catheterization time was less than 2 days and hospitalization of 3 days. Detrusor muscle was present in the histopathology report of 37 patients (92.5 %). None of the patients needed a switch to conventional TURBT. Overall complication rate was low (Clavien = 3, n = 5 [12.5 %]). No patient needed blood transfusion and no patient had any obturator spasms or bladder perforation. At 4-hours post-op 35 patients had clear urine. CONCLUSIONS En-bloc holmium laser excision of bladder tumors is feasible safe and effective. © 2018FiguresReferencesRelatedDetails Volume 199Issue 4SApril 2018Page: e1118-e1119 Advertisement Copyright & Permissions© 2018MetricsAuthor Information Pankaj Maheshwari More articles by this author Saurabh Patil More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Ureteroscopic holmium laser-assisted retrograde nephrostomy access: a novel approach to percutaneous stone removal.

Percutaneous nephrolithotomy remains a challenging procedure primarily due to difficulties obtaining access. Indeed, few urologists obtain their own access due to difficulties using a fluoroscopic or ultrasonic based antegrade puncture technique. Herein we report the first experience using holmium laser energy to obtain access in a retrograde fashion. After a pretreatment week of tamsulosin 0.4mg/day (one center only) and following a documented sterile urine, a total of ten patients underwent retrograde holmium laser-assisted endoscopic-guided nephrostomy access in a prone split leg position. In nine of ten patients, ureteroscopic guided, holmium laser access via an upper pole posterior calyx was achieved. In one patient, the laser tract could not be safely dilated and antegrade endoscopic and fluoroscopic guided access was performed. The mean operative time was 202min; the mean fluoroscopy time was 32s (6/9 cases). The mean pre-operative stone volume was 14,420mm3. CT imaging on post-operative day 1 revealed 6/6 patients had residual stone fragments with total mean volume of 250mm3 (96% reduction); there were no residual fragments in three patients who were evaluated with non-CT radiographic imaging (KUB). There was a single complication requiring angioembolization due to a subcapsular hematoma with associated secondary tearing of an inter-polar vessel remote from the nephrostomy site. Holmium laser-assisted endoscopic-guided retrograde access in a prone split-leg position was successfully performed at two institutions. The accuracy of nephrostomy placement and lessening of fluoroscopy time are two potential benefits of this approach.

MP02-13 PROSTATE ENUCLEATION TECHNIQUE: SHORT TERM RESULTS OF PROSPECTIVE RANDOMIZED TRIAL OF COMPARING HOLMIUM LASER AND BIPOLAR ENERGY FOR OBSTRUCTIVE BPH.

You have accessJournal of UrologyBenign Prostatic Hyperplasia: Surgical Therapy & New Technology I1 Apr 2017MP02-13 PROSTATE ENUCLEATION TECHNIQUE: SHORT TERM RESULTS OF PROSPECTIVE RANDOMIZED TRIAL OF COMPARING HOLMIUM LASER AND BIPOLAR ENERGY FOR OBSTRUCTIVE BPH. Ajay Bhandarkar Ajay BhandarkarAjay Bhandarkar More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2017.02.109AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Techniques of Prostatic Adenoma Enucleation by variety of energy sources are commonly practiced for surgical treatment of Obstructive BPH. We compare our short term results of Holmium Laser Enucleation (HoLEP ) and Bipolar Enucleation (PKEP/TUEB) in a prospective Randomized trial. METHODS Between August'15 and April'16, a total of 98 patients with Obtructive BPH were treated and prospectively analysed at our center. A computerized randomization schedule was used. HolEP was done in 52 and Bipolar Enucleation was done in 46 patients. All Patients were evaluated by IPSS, Maximum Flow Rates (Qmax), Transrectal Ultrasound Guided Prostate Volume(PV), Post Void Residue(PVR) and PSA. 100 W Holmium Laser and Plasmakinetic Bipolar energy by Spatula/Button Electrode was used for enucleation by single surgeon. Primary end points were IPSS and Qmax, secondary being reduction in PVR and PSA. Intraoperative and Immediate postoperative data like OR Time, Blood Loss, Irrigation Volume, Catherization/hospitalization time were compared between two groups. RESULTS Pre-operative Demographics in both groups were comparable including Prostate Volume, HolEP (58± 8.2gms) versus Bipolar Enucleation (56.5±6.8 gms) p value being >0.05. Primary and secondary end points were comparable for both groups (p>.001). Blood loss in HolEP was marginally superior to Bipolar Enucleation (36±8.5 ml versus 68.5±7ml respectively, p=0.123). There was no significant difference in other parameters in both groups. OR time (34.5 versus 37 minutes) Catheterisation time (2.8 versus 3.1 days), Irrigation Volume (16.9 L versus 17.6 L), Hospital Stay ( 3.4 versus 3.9 days). One patient had prolonged hematuria, without requiring any intervention in bipolar group and two patients in each group had SUI lasting 3-4 weeks. There was no statistically significant difference in Primary and secondary end points in both groups at 1, 3 and 6 month follow-up. CONCLUSIONS Endoscopic Enucleation is effective irrespective of Energy source. Mean Prostate volume in our study was suggestive of Medium size Obstructive BPH, where, Bipolar Enucleation of Prostate was found to be equally efficacious compared with HoLEP in Short term follow-up. However, long term follow-up results in larger Prostate Volume remains to be seen. © 2017FiguresReferencesRelatedDetails Volume 197Issue 4SApril 2017Page: e15 Advertisement Copyright & Permissions© 2017MetricsAuthor Information Ajay Bhandarkar More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Large Dumbbell Shaped Vesicovaginal Calculus Managed with Holmium Laser Cystolithotripsy Followed by Staged Repair of Vesicovaginal Fistula

Complicated Vesicovaginal Fistulae (VVF) is prevalent in developing countries following obstetric injury. We report a rare case of a large dumbbell shaped vesicovaginal calculus measuring 7x 4.6cm in a patient with recurrent, complicated VVF managed successfully in two stages 6 weeks apart. Holmium laser (30 Watt) cystolithotripsy was used to break the vesical portion of the stone at the waist of the dumbbell, followed by delivery of vaginal part of the stone. Trans-abdominal VVF repair (O'Connor method) with omental interposition flap with right side ureteric reimplant was done after six weeks. Our case was unique because of occurrence of a larger sized fistula after a gynaecological surgery. She had developed larger stone (weight more than190gm- vaginal component) into the fistula tract. Also she had undergone multiple failed VVF repair attempts before. Use of holmium laser energy to break the stone was unique which minimized the morbidity of the first procedure leading to early recovery followed by staged repair of fistula after six weeks.

V332 HOLMIUM LASER INCISION OF BLADDER NECK FOR POST-PROSTATECTOMY BLADDER NECK STENOSIS

You have accessJournal of UrologyMale Voiding Dysfunction (BPH & Incontinence) & Infection1 Apr 2010V332 HOLMIUM LASER INCISION OF BLADDER NECK FOR POST-PROSTATECTOMY BLADDER NECK STENOSIS Hemendra Shah Hemendra ShahHemendra Shah More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2010.02.397AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Bladder neck stenosis is an inherent long term complication of prostatectomy for bladder outlet obstruction. We present our experience with Holmium laser incision of post-prostatectomy bladder neck stenosis. To the best of our knowledge, there is no information on the outcome of this procedure in the literature. METHODS Retrospective review of 11 patients with post-prostatectomy bladder neck stenosis who underwent bladder neck incision with holmium laser at our institute from May 2003 to June 2008 was performed. All patients had an ascending urethrogram & cystoscopy to diagnose bladder neck stenosis. The procedure was performed using 550 μ laser fiber at 100 W holmium laser energy. Initially incision was taken at 5 and 7o clock position and deepened till all fibrous tissue is cut. Later on the fibrous tissue is resected using the holmium laser. An additional 12 o clock &/or 6o clock incision is take to completely release all the fibrous tissue. The remaining residual fibrous tissue is vaporized. All patients had a per urethral catheter for 1 day. Patients demographic and perioperative data was analyzed to know the safety and efficacy of the procedure. Follow-up data was obtained to know early outcome of surgery. Digital video clips from previously recorded Holmium laser incision of post-prostatectomy bladder neck stenosis were edited into a video describing the steps of procedures. RESULTS The primary procedure for prostatectomy was open prostatectomy (1); TURP (7) and HoLEP (3). All patients presented with recurrent bladder outlet obstruction after initial prostatectomy. The mean interval between prior prostatectomy and presentation was 1.9 years (3 months – 9 years). The mean pre-prostatectomy prostate size (available in 8 patients) was 34.8 gm (11- 72 gm). The mean preoperative AUA symptom score, maximum uroflow rate and post-void residual urine were 24, 7.2 ml/sec and 112 ml respectively. There were no major intraoperative or post-operative complications. At mean follow-up of 21 months, no patients had recurrent bladder neck stenosis. The mean postoperative AUA symptom score, maximum uroflow rate and post-void residual urine during last available follow-up were 7, 19.8 ml/sec and 33 ml respectively. CONCLUSIONS Holmium laser bladder neck incision is associated with favorable early postoperative outcome. Mumbai, India© 2010 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 183Issue 4SApril 2010Page: e132 Peer Review Report Advertisement Copyright & Permissions© 2010 by American Urological Association Education and Research, Inc.MetricsAuthor Information Hemendra Shah More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Shock Wave Lithotripsy Versus Semirigid Ureteroscopy for Proximal Ureteral Calculi (

To use a matched-pair analysis design to compare the safety and efficacy of shock wave lithotripsy (SWL) and ureteroscopy (URS). Controversy still exists regarding whether SWL or URS is the best management of upper ureteral calculi. We reviewed the records of patients with a single radiopaque upper ureteral stone treated by URS or SWL from January 2003 to December 2005. SWL was performed as an outpatient procedure using the electromagnetic lithotripter (Dornier Lithotripter S). URS was performed using an 8F or 8.5F semirigid ureteroscope. Intracorporeal lithotripsy with pneumatic or holmium laser energy was used when needed. A matched-pair analysis was performed using 3 parameters (sex, stone size, and degree of hydronephrosis). The success rates, retreatment rates, auxiliary procedures, and complications were compared in each group. A total of 427 patients were treated for upper ureteral stones. Forty-three matched pairs were identified and compared. The success rate was 83.7% for SWL vs 88.4% for URS (P = .8). The retreatment rate was significantly greater in the SWL group than in the URS group (65% vs 2.3%, respectively; P < .001). The need for auxiliary procedures was equal in both groups (16.3%). The complication rate was 14% in the URS group and 4.7% in the SWL group (P = .1). SWL and semirigid URS are highly effective in the treatment of proximal ureteral stones <20 mm. The results of our study showed that SWL was safer and less invasive, but that URS was more effective and resulted in a lower retreatment rate.

Lower Calyceal Occlusion by Autologous Blood Clot to Prevent Stone Fragment Reaccumulation after Retrograde Intra-Renal Surgery for Lower Calyceal Stones: First Experience of a New Technique

We tested the hypothesis that lower calyceal (LC) autologous blood clot (ABC) occlusion, after retrograde intra-renal surgery (RIRS) may prevent LC fragment reaccumulation where all fragments cannot be directly removed. Over two years, patients with LC stones >6 mm <2 cm, that had presented de-novo or failed primary SWL or PNL elsewhere, were treated with RIRS. After intra-renal relocation into a favorable lie, stones were fragmented with Holmium laser energy to <3 mm, suitable for spontaneous passage. The LC was filled with 5-10 cc venous autologous blood with the patient in reverse Trendelenberg, leaving the blood to clot. After confirmatory pyelogram a DJ stent was placed. Ultrasound and KUB at 3 months assessed stone free rate. This technique was tested in 35 patients with LC calculi (16 as primary treatment, and 19 as salvage for residual fragments post SWL or PNL). Nine salvage patients had indwelling DJ stents (three significantly encrusted at RIRS). Nine unstented patients had upper ureteral tortuosities or narrowing limiting multiple instrument passes for stone removal. Median maximum stone dimension was 1.2 cm. All were successfully relocated & fragmented. A Nitinol basket was required for stone relocation in 60%. All but one occlusion procedures succeeded at the first attempt. None required re-admission for clot colic. Only 8.6% required more than overnight hospital stay. Three and six month stone free rates were 94% and 97% respectively. The simple LC autologous blood clot occlusion technique after RIRS, for difficult LC stones, validates our hypothesis and results in excellent stone free rates, while minimizing ureteral trauma from multiple instrument passages needed for active fragment removal. This study supports the need for multi-center experience of this technique to validate our results.

In vitro effects of pulsed holmium laser energy on canine uroliths and porcine cadaveric urethra.

To assess the effect of holmium laser energy on canine uroliths and porcine urethra. Uroliths of known composition and fresh cadaveric urethra were exposed to holmium laser energy. Urolith fragmentation times and depth of urethral lesions were determined. Overall mean fragmentation time was 11.8 +/- 8.01 seconds. Magnesium ammonium phosphate (MAP) and urate uroliths had significantly shorter fragmentation times compared to other uroliths. Fragmentation time of MAP uroliths irradiated with 1.2 J/pulse was significantly longer than the fragmentation time of MAP uroliths irradiated with 0.3 J/pulse. Overall mean lesion depth for urethral specimens treated with 90 degrees contact mode irradiation was significantly greater than overall mean lesion depth for specimens treated with 30 degrees non-contact mode. Holmium laser energy effectively fragmented canine uroliths and caused minimal urethral damage in vitro. Dogs with urolithiasis may represent a useful animal model for developing human lithotripsy procedures.

Fragmentation of uric acid calculi with the holmium: YAG laser produces cyanide.

To independently test previously reported findings of cyanide evolution under holmium:yttrium aluminum garnet (Ho:YAG) (holmium) lithotripsy of uric acid calculi, determine if this occurs with other forms of intracorporeal lithotripsy, and establish if this occurs due to a photothermal, photochemical, or photoacoustic reaction. Human uric acid calculi were fragmented in vitro through exposure to holmium, ultrasound, and electrohydraulic (EHL) energy sources. The following parameters were varied: total laser energy, individual laser pulse energy, ultrasonic energies, and EHL energies. Uric acid powder was suspended in solution and exposed to holmium laser energy in vitro. Serum and irrigant samples from a human patient were collected following intrarenal holmium lithotripsy of a uric acid calculus. All samples were analyzed for hydrogen cyanide (HCN) content. Holmium lithotripsy of solid uric acid calculi produces cyanide. The yield is linearly dependent upon total laser energy delivered. Pulse energy does not affect cyanide yield. Photothermal mechanisms coupling laser energy to the solid crystal lattice are responsible for the production of cyanide. Ultrasound and EHL lithotripsy do not produce cyanide. A clinically insignificant level of cyanide was detected in the blood of a single patient following laser lithotripsy of a uric acid calculus. Our study confirms that cyanide is produced by a photothermal mechanism during holmium laser lithotripsy of uric acid calculi, and that the amount produced is clinically insignificant.

CALYCEAL DIVERTICULA: Ureteroscopic Management

In selected cases, RIRS management of calyceal diverticula and its related problems has been shown to be more efficacious than ESWL monotherapy and avoids the potential complications and discomfort of percutaneous and laparoscopic procedures. The advent of the Holmium laser energy source, with innovations such as the flexible ureteroscope and the tipless stone basket, have expanded the role of RIRS in the management of calyceal diverticula and associated problems. Presently, RIRS is the initial treatment choice for the management of low to moderate stone burdens that are contained in calyceal diverticula or trapped behind any narrowed intrarenal segment (e.g., infundibular stenosis). If repair of the stenotic segment is not successful, thereby excluding stone treatment, then under the same anesthesia, the patient undergoes a percutaneous antegrade renal surgery. The authors feel that the percutaneous approach as a first choice is more suitable for posteriorly located diverticula with a large stone burden. In selected cases of anteriorly located diverticula with large stone burdens, the laparoscopic approach is more expedient.

Holmium laser enucleation of the prostate with tissue morcellation: initial United States experience.

BENIGN PROSTATIC HYPERPLASIA (BPH) affects 70% of men over age 70 and is a significant cause of morbid. ity in this population.1 Endoscopic surgery for BPH has evolved over the past decade with technological advances that offer significant advantages in perioperative and postoperative morbidity and hospital stay. One of the technological advances has been the holmium laser, a multifunction tool in urology that can be used for intracorporeallithotripsy, stricture and ureteropelvic junction incision, excision and ablation of urothelial tumors or condylomata, and resection/vaporization of prostatic adenomataus tissue. We report the initial use in the United States of the holmium laser with transurethral tissue morcellation for the endoscopic treatment of BPH. The surgical technique for the use of the holmium laser in the treatment of BPH has evolved over the past 5 years, due in large part to the work of Gilling and associates.25 Initially, the holmium laser energy was used in concert with Nd:YAG energy to vaporize and coagulate tissue, and the procedure was termed endoscopic laser ablation of the or CELAP. Unfortunately, many of the irritative voiding symptoms experienced by patients undergoing visual laser ablation of the prostate (VLAP) with the Nd: Y AG laser were also seen using the dual-laser technique. Vaporization alone was next used with holmium energy (holmium laser ablation of the prostate, or HoLAP) with excellent voiding results and low rates of transfusions, but the time required to vaporize significant volumes of adenoma was excessive. Using the holmium laser to resect the prostate into its anatomic lobes (HoLRP) was the next step in the development of the technique. This method also provided excellent results, but the issue of how to remove the large adenomas from the bladder after resection was unresolved. Development of a transurethral tissue morcellator now allows efficient removal of adenomatous tissue of any size. The technique has progressed to a true anatomic enucleation, similar to an endoscopic open ·prostatectomy, abbreviated HoLEP (holmium laser enucleation of prostate), which is the procedure on which this work is based. The surgical advantages of HoLEP compared with standard transurethral electroresection (TURP) are in the areas of blood loss and electrolytic effects of irrigant. The laser technique is hemostatic, allowing operation in a virtually bloodless field, and decreases or eliminates the need for postoperative bladder irrigation. Consequently, catheters may be removed earlier, length of stay is decreased, and return to normal activity is hastened. The reported blood transfusion rate is 1 per 1000 procedures.6 Additionally, patients with altered coagulation profiles from therapeutic or pathologic etiologies may undergo HoLEP without increased bleeding complications. Because thermal energy is the mechanism through which the holmium laser works, physiologic irrigants, such as normal saline, may be used for HoLEP. The use of normal saline eliminates the risk of dilutional hyponatremia and potential TUR syndrome. The combination of the hemostatic capabilities of the holmium laser and transurethral tissue morcellation allow enucleated adenoma of very large size to be removed effectively from the bladder, offering a possible alternative to open prostatectomy. In this work, we review the first 61 HoLEPs with tissue morcellation performed at our institution.

The Holmium Laser for the Treatment of Benign Prostatic Hyperplasia: A Brief Review

At a wavelength of 2140 nm, the holmium:YAG (Ho:YAG) laser can be used for incision, ablation and resection of prostatic tissue. This laser has revolutionised the surgical management of benign prostatic hyperplasia (BPH) in our institution. Five different techniques have been utilised in evolving the current techniques using the Ho:YAG laser either alone or in combination with neodymium:YAG (Nd:YAG laser for the surgical management of BPH. The clinical outcome of 664 patients undergoing these procedures is presented.Enucleation of the prostatic adenoma using the holmium laser energy is the most common procedure presently performed at our institution for the surgical management of BPH. A mechanical tissue morcellator appears to be the most efficient way to remove prostatic tissue, once enucleated, from within the bladder.

Principles and applications of laser lithotripsy: experience with the holmium laser lithotrite.

The initial clinical experience with holmium laser energy applied for endoscopic lithotripsy was positive. The current study is presented as a contrast to the preliminary findings and as a means of defining the clinical usefulness of this specific laser lithotrite. Calculi were treated endoscopically with the holmium laser lithotriptor and data was gathered prospectively. The youngest patient in the series was a thirteen-month--old who underwent percutaneous therapy, while the youngest patient on whom a retrograde endoscopic procedure was performed was a six-year old male patient with a proximal ureteral calculus. Lower water density, quartz fibers delivery systems were developed and employed. Fiber diameters ranged from 200-1000 micrograms. The smaller fibers were employed most commonly through the actively deflectable, flexible endoscope to facilitate treatment with maximum deflection. Larger fibers, with their much larger vaporization bubbles, were used through rigid endoscopes to debulk large stone burdens. A total of 210 patients with 249 calculi were treated. All major stone compositions were treated with minimal variation in laser efficiency. All but three of 109 ureteral calculi were treated in a retrograde fashion to completion (i.e., "stone free") in one sitting (97%). One-hundred thirteen renal stone burdens were treated with the holmium laser; 99 of these were treated solely in a retrograde fashion. Of the latter, 79 (80%) required only a single session. The combination of the actively deflectable, flexible ureteroscope and the 200-micrograms fiber facilitated treatment to completion of 38 to 45 lower-pole caliceal calculi (85%). The success of ureteropyeloscopic lithotripsy with the holmium laser for all intrarenal calculi, including staged or second sitting for large complex stone burdens, was 90%. Sixteen percutaneous procedures (13 renal and 3 ureteral calculi) employed the holmium laser as an endoscopic lithotrite. All 28 patients with large bladder calculi with a mean diameter of 41.8 mm were treated to completion in one sitting. Complications from holmium laser energy, including postoperative ureteral stricture disease, were not encountered in this series. Holmium laser energy is uniquely suited to treat urinary calculi safely regardless of stone size, location, or metabolic composition, and has particular efficacy in complex clinical presentations.

Experience with the holmium laser as an endoscopic lithotrite

Objectives To study, in a clinical series, the safety and efficacy of holmium laser energy applied as an endoscopic lithotrite. Methods Over a 2-year period, patients with urinary tract calculi were treated endoscopically with the holmium laser lithotripter and data were gathered prospectively. Holmium lasers with maximum outputs of 15, 25 and 60 W were used. Various low water density, quartz fiber delivery systems were developed for specific applications. In addition, various combinations of endoscopes and laser fibers were employed. Results A total of 63 patients with 75 calculi were treated. All calculi were cleared endoscopically. Minimal variation in laser efficiency was noted with different stone compositions, including cystine. Thirty-three of 34 ureteral calculi were treated to completion in one sitting (97%). Twenty-nine renal stone burdens were treated with the holmium laser, 26 of which were treated solely in a retrograde fashion. Of the latter, 23 (88.5%) required only a single sitting. Complications from holmium laser energy, including ureteral stricture disease, were not encountered in this series. Patients with complex, large stone burdens were treated to completion without sequelae. The combination of the actively deflectable, flexible ureteroscope and 200-^m fiber facilitated clearance of 18 lower-pole caliceal calculi. Three patients with partial staghorn stone burdens averaging 30 mm in diameter were treated ureteroscopically. Chronic urinary infections that were problematic preoperatively completely resolved after therapy. All 12 patients who had large bladder calculi with a mean diameter of 55.8 mm were treated to completion in one sitting. Conclusions Holmium laser energy is uniquely suited to treat all urinary calculi safely and effectively.