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

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

INTRODUCTION AND OBJECTIVES:Ureteroscopic laser lithotripsy most commonly uses a Holmium:YAG (Ho:YAG) laser to achieve urinary stone comminution. Stone erosion and fragmentation occurs through phot...

INTRODUCTION AND OBJECTIVES:The holmium-YAG (Ho:YAG) laser system (LS) is the prevailing standard of care for laser lithotripsy (LL). The Super Pulse Thulium Fiber Laser (SPTF) has emerged as an ef...

INTRODUCTION AND OBJECTIVES:Thulium fiber laser technology is an emerging field for laser lithotripsy that addresses inherent limitations of the Holmium:YAG laser including high current requirement...

INTRODUCTION AND OBJECTIVES:Holmium:YAG laser is the current lithotrite of choice. Although improvements such as higher pulse frequency, longer pulse duration, and multi-pulse technology have advan...

Objectives: Holmium: YAG laser has gained its popularity throughout the years and is used to treat sialolithiasis, which helps to overcome the limitations of traditional sialendoscopic lithotripsy for larger-sized salivary stones. However, little information is available regarding factors predicting the success rate of Holmium: YAG laser intraductal lithotripsy. The purpose of this study is to investigate the factors affecting the success rates of Holmium: YAG laser lithotripsy for salivary stones treatment in a tertiary care hospital. Methods: A retrospective study conducted in patients receiving sialolithiasis surgery under sialendoscopy from May 2013 to March 2015 at Mackay Memorial Hospital, Taiwan. Data on various factors, including patients’ age, gender, glands, size of largest stone, multiple stones (≥2 stones), location of the stone (distal duct, middle duct, proximal duct, and hilum), and operative time. The success of the surgery defined as patients without any complaints such as swelling or tenderness. Logistic regression and Fisher exact tests were employed to examine these factors on the success rate. Results: Fifty-four patients who received sialendoscopy surgery with a mean age of 35.74 years old recruited. Logistic regression identified the operation time exceeding 210 minutes showed 23.497 folds higher odd ratio of having a result of operation failure ( P < .05). Conclusion: The prolonged operation time is the sole independent factor affecting the successful outcome for salivary gland intraductal laser lithotripsy. We recommend operative time be no more than 210 minutes to increase the success rate in salivary gland Holmium: YAG laser intraductal lithotripsy.

Bouveret's syndrome is a rare presentation of duodenal obstruction or gastric outlet obstruction caused by a large gallstone migrating through a cholecystoduodenal or choledochoduodenal fistula. Most patients are elderly and often have underlying comorbidities, complicating surgery. Endoscopic therapy should be used as first-line treatment for these patients who are not good surgical candidates. We report a case of a 98-year-old Chinese female who presented with vomiting for three days. Esophagogastroduodenoscopy and computed tomography confirmed the diagnosis of Bouveret's syndrome. The patient successfully underwent endoscopic lithotripsy with the Holmium: Yttrium–Aluminum–Garnet (Ho: YAG) laser. Ho: YAG laser lithotripsy has been used to treat Bouveret's syndrome in four case reports. It can be recommended in patients with Bouveret's syndrome who are poor candidates for surgery. SIMILAR CASES PUBLISHED: 4

The objective of this study was to determine the outcomes associated with the endoscopic removal of foreign bodies (such as mesh or permanent suture) in the lower urinary tract after female stress incontinence surgery with the Holmium:YAG (Ho:YAG) laser, and to systematically review the literature on this topic.A retrospective chart review of 18 consecutive women found to have mesh or suture exposure was performed. All patients underwent Ho:YAG laser ablation. A systematic review was performed to identify literature addressing the endoscopic management of mesh/suture exposure after stress incontinence surgery.Between November 2011 and February 2016, 18 women underwent Ho:YAG laser ablation of exposed mesh or suture. Presenting symptoms included lower urinary tract symptoms, pelvic pain, incontinence, or recurrent urinary tract infections. Thirteen women had a previous synthetic midurethral sling and five had a prior retropubic suspension. The median age was 58 years (interquartile range [IQR] 50-60) and median follow-up was 2 years (IQR 1-2). Four patients (22%) had residual mesh after the first procedure, requiring a repeat endoscopic procedure. Only one patient had a small amount of asymptomatic residual mesh on cystoscopy after the final procedure. Only minor postoperative complications were observed. Eight patients had stress incontinence and four underwent operative treatment for this. In our systematic review, we identified 16 case series, which described a total of 158 patients. Women most commonly presented with voiding symptoms or incontinence. Based on the synthesis of these data, repeat procedures were necessary in 16% and vesicovaginal fistula occurred in 2%. Recurrent/persistent stress incontinence was present in 20%, and of these patients, 3/4 underwent a new stress incontinence procedure.Both our case series and the systematic review of the literature demonstrated that endoscopic treatment of lower urinary tract foreign bodies after stress incontinence surgery has good success rates and minimal morbidity.

Study Objective To evaluate the efficacy and safety of hysteroscopic adhesiolysis with Holmium YAG (Ho:YAG) Laser in patients with stage 2 and 3 Asherman's syndrome (ASRM classification). Design Prospective study of patients operated from April 2016 to August 2019. Setting Tertiary centre dedicated to Obstetrics, Gynaecology and Urology. Patients or Participants 23 women of Asherman's syndrome diagnosed on the basis of clinical presentation, transvaginal ultrasound and hysteroscopy. Interventions Hysteroscopic adhesiolysis was done using Holmium YAG laser delivered through a 400 micron quartz fibre at a power setting of 15 Watts. Normal saline at a pressure of 100 mm of Hg was used as the distending medium. Simultaneous laparoscopy was done in 14 patients. Post-operative intracavitary Foley catheter and sequential oestrogen & progesterone therapy was given for prevention of adhesion recurrence. Relook hysteroscopy was done in all patients after 2 months. Measurements and Main Results Mean operative time was 25 minutes (18 – 45 minutes). Stage 2 adhesions were seen in 15 patients & stage 3 in 8 patients. There were no intra or post-operative complications. 22 patients regained normal menstrual pattern (average flow). There were flimsy adhesions in 3 patients and dense adhesions in 1 patient on relook hysteroscopy. Adhesiolysis was done again with Ho:YAG laser. Mid cycle transvaginal ultrasound showed significant improvement in endometrial thickness (average of 7.4 mm). Follow up of the 18 patients for 12 months showed clinical pregnancies in 12 patients (66.7%) & 9 live births (50.0%) without any intra or postpartum complications. Conclusion Hysteroscopic adhesiolysis with Holmium YAG laser in stage 2 and stage 3 Asherman's syndrome is an effective, safe and easy procedure which helps to improve the menstrual function and the reproductive outcome in these patients.

Background: No consensus management is available for the bladder neck contracture (BNC) secondary to radical retropubic prostatectomy (RRP). We present our experience of a technique in which holmium: YAG surgical laser was utilized transurethrally to incise the stenotic area. Methods: Incisions with holmium: YAG surgical laser were made in 34 subjects with BNC between January 2012 and May 2018. Medical charts were reviewed to evaluate related data including medical history, international prostate symptoms score, uroflowmetry, and recurrence of the stricture. Results: The mean length of operation was 34 ± 4.06 minutes. No significant postoperative or perioperative complications were noted. The median length of hospital stay after surgery was two days. Five subjects (13.8%) required endoscopic holmium: YAG laser retreatment. After the first treatment with holmium: YAG surgical laser, the mean duration for recurrence was 4.3 months. In addition, significant improvements were observed in Qmax, residual urine volume, and the total IPSS score. Conclusions: BNC after RRP is relatively frequent but it can be safely and effectively managed by transurethral holmium: YAG laser incision

Background: Among many lithotripters available for fragmentation of ureteric stones, pneumatic and Holmium: YAG laser lithotripsy have reported favorable outcomes. Aim of this study is to compare the intracorporeal Holmium: YAG laser with pneumatic lithotripsy in ureteral calculi fragmentation in terms of fragmentation time, stone migration, intra-operative and post-operative complications, stone free rate and need for auxiliary procedures. Material & Methods: Fifty patients selected with diagnosis of calculus in ureter suitable for endoscopic treatment. They were subsequently randomized in to two groups by sealed envelope method. Group 1 was treated with Holmium: YAG laser lithotripsy and group 2 with pneumatic lithotripsy. All patients with ureteral calculi of size 6-20 mm were included while stone size >20mm, patients with sign of sepsis, pregnancy, renal insufficiency or urinary tract abnormalities were excluded from the study. Results: Maximum number of cases (64%) were from 21-40 years age group in both the groups, while least number of cases (8% of all) were from age group

Background: Among various intracorporeal lithotripters, pneumatic lithotripter has become the widely used tool for the treatment of urinary stones. Recently the holmium: YAG laser has been used with a wide range of potential urological applications, including intracorporeal lithotripsy of urinary calculi. Purpose: Compare the effectiveness and complications of treatment for ureteric stones between holmium laser lithotripsy and pneumatic lithotripsy. Material and Methods: Comparison of 100 patients presented with ureteric stones, group one (50) of whom were treated with pneumatic lithotripsy and group two (50) with holmium laser was done and the effectiveness and complications of both were analyzed. Results: There was no difference in patient age, sex, stone size and location of stones between the two groups. The immediate stone free rates were 88% in the holmium: YAG group and 66% in the pneumatic lithotripsy group (p < 0.05). The four weeks stone free rates were 98% and 94% respectively (p = 0.07). The mean ± SD operative time in the holmium: YAG group (40 ± 26 min) was shorter than those with pneumatic lithotripsy group (60 ± 40 min). Postoperative stay in hospital was less than 24 hours in holmium: YAG group (70.4%) and shorter than those for pneumatic group (29.6%) (p < 0.002). Post treatment complications such as ureteral perforation were encountered in only two patients who underwent pneumatic lithotripsy. Other complications, such as mucosal injury, ureteral perforation and postoperative fever; there was no statistically significant difference between the two groups. While light hematuria was found more frequently in the pneumatic group (14%) in comparison to laser group (12%) (p = 0.02). On the other hand, the overall complication rates between the two groups was statistically significant (8%) laser group vs. (32%) pneumatic group (p = 0.003). Conclusions: Holmium: YAG laser lithotripsy was associated with shorter operation time and postoperative hospitalization period. These data suggest that holmium: YAG lithotripsy was safe and more effective than Pneumatic lithotripsy in the aspect of immediate stone free rate. We believe that holmium: YAG is an excellent treatment modality for managing ureteral calculi.

The holmium YAG (Ho:YAG) laser penetration depth (PD) of 0.4 mm has been widely described. Nonetheless, in physics, this concept refers to the tissue thickness at which 90% of the energy has been absorbed and not to the incision depth (ID) that the laser can achieve in tissue. The aim of this study is to evaluate the ablation efficiency of Ho:YAG laser on soft tissue.With an automated robotic arm, systematic fissures were performed on flat veal kidney specimens. Broad setting spectrums from 2.5 to 80 W, short and long pulse, were tested with 272 and 365 μm laser fibers. Experiments were repeated three times. Two pathologists in a blinded manner measured the width, depth, and coagulation area with electronic microscopy.The overall mean ID was 2 mm (0.25-4.39) and the mean width was 1 mm (0.3-3.1). The mean coagulation thickness was 0.48 mm (0.25-1.73). The higher the frequency and energy, the deeper and wider was the incision p 0.001. No differences were observed regarding the fiber diameter. The pulse length did not affect the ID, although the mean width was greater with short pulse p = 0.04. The outer mean coagulation was increased by increasing energy but not by increasing frequency p 0.119.The overall mean ID was significantly higher than the theoretical 0.4 mm PD described for Ho:YAG laser. The energy, frequency, and pulse length had individual effects regarding ID, incision width, and coagulation. The ID should be specified in accordance with the laser's power output and should not be confused with the physics of PD concept.

The holmium:YAG (Ho:YAG) laser is effectively used for transurethral ureterolithotripsy. The laser is applied through an optical fiber in a ureter. A bubble is formed by a laser irradiated from the fiber tip and a calculus is crushed by the impact of the bubble collapse. In this study, we observed the characteristic behavior of a bubble induced by a Ho:YAG laser near a wall surface, using a high-speed video camera. Furthermore, we measured the forces of a bubble collapse using an impulsive force sensor. As a result, we showed characteristic bubble collapse behavior and impulsive force distribution for various fiber placement conditions.

Objective To evaluate the factors that may affect the efficacy and safety of ureteroscopy with holmium:YAG laser lithotripsy in the management of ureteral stones in preschool children. Materials and Methods Medical records of 70 children, 32 boys and 38 girls, who were treated for ureteral stones at our clinic between 2014 and 2016 were retrospectively reviewed. Patients were grouped according to size of the instrument used as group 1 (n = 40, ultrathin 4.5 Fr) and group 2 (n = 30, 7.5 Fr). Patient age, stone characteristics, and operative and postoperative outcomes were compared. The effect of age, stone size and location, type of the instrument, and operative times on success and complication rates were also investigated. In addition, factors related with postoperative hydronephrosis were evaluated. Results Patients in group 1 were significantly younger than group 2 (32.22 ± 22.72 vs 63.53 ± 16.98 months, P = .000). Groups were similar in terms of gender, stone laterality, size and location, and operative times. However, access failure rate was significantly higher in group 2 (0 vs 20%, P = .022). Stone-free rate was 87.5% in group 1 and 76.6% in group 2 ( P = .237), complication rates were not significantly different among groups. Stone size and location were found to be associated with success rates. Stone location and operative times were the factors affecting the complication rates. Presence of preoperative hydronephrosis and prolonged operative time were determined as the predictors of postoperative hydronephrosis. Conclusion Ultrathin ureteroscopy with laser lithotripsy can be used safely and effectively for ureteral calculi including proximal ones in significantly younger children without any access failure.

Surveillance cystoscopy for bladder cancer following transurethral resection of the prostate (TURP) can have unexpected consequences, such as the detachment of the resectoscope beak. This is an infrequent event, with few published or standard techniques for its retrieval. These techniques range from the use of forceps, as Grainger et al described in the first published case report on resectoscope sheath extraction, to the use a holmium YAG laser with a 200 μm fiber to fragment the 26 French (Fr) resectoscope sheath in the patient’s bladder and other laser-based techniques. We hypothesize that resectoscope beak extraction can be achieved efficiently and safely using a flexible cystoscope in the absence of a laser apparatus and with better postoperative results than rigid resectoscope or forceps for extraction.

The purpose of this study was to evaluate the popcorn technique using a wide range of holmium laser settings and fiber sizes in a systematic in vitro assessment.Evaluations were done with 4 artificial stones in a collection tube. A fixed ureteroscope was inserted through a ureteral access sheath to provide constant irrigation flow and the laser was placed 1 mm from the bottom. Combinations of 0.5 to 1.5 J, 10 to 20 and 40 Hz, and long and short pulses were tested for 2 and 4 minutes. We used 273 and 365 μm laser fibers. All tests were repeated 3 times. The stones were weighed before and after the experiments to evaluate the setting efficiency. Significant predictors of a highly efficient technique were assessed.A total of 144 tests were performed. Mean starting weight of the stones was 0.23 gm, which was consistent among the groups. After the experiment the median weight difference was 0.07 gm (range 0.01 to 0.24). When designating a 50% reduction in stone volume as the threshold indicating high efficiency, the significant predictors of an efficient popcorn technique were a long pulse (OR 2.7, 95% CI 1.05-7.15), a longer duration (OR 11.4, 95% CI 3.88-33.29), a small (273 μm) laser fiber (OR 0.23, 95% CI 0.08-0.70) and higher power (W) (OR 1.14, 95% CI 1.09-1.20).Higher energy, a longer pulse, frequencies higher than 10 Hz, a longer duration and a smaller laser fiber predict a popcorn technique that is more efficient at reducing stone volume.

Objective: The aim of this prospective single-blinded study was to analyze the stone-free (SF) rates between pneumatic lithotripsy (PL) and laser lithotripsy (LL) for the treatment of single and primary ureteral stones and to evaluate potentially predictive factors of a SF status. Material and Methods: From January 2010 to January 2011, 133 consecutive patients with single and primary ureteral stones were prospectively enrolled. Uni- and multivariate logistic regression were performed to estimate predictive factors of a SF status. Results: The SF rate in the PL group was 80.7 and 86.1% in the LL group (p = 0.002). Success rates with regard of stone position were not significantly different between groups. At univariate logistic regression, middle ureteral stone (OR 3.33, p = 0.04), distal ureteral stone (OR 4.4, p = 0.02), LL (OR 3.05, p = 0.04) and Hounsfield units (HUs) (OR 1.07, p = 0.03) were significantly predictive factors of a SF status. At a multivariate logistic regression, middle ureteral stone (OR 5.58, p = 0.01), distal ureteral stone (OR 7.87, p < 0.01), LL (OR 2.4, p = 0.02) and HUs ≥1,200 (OR 1.15, p = 0.02) were significantly associated with a SF status. Conclusions: LL significantly influences the SF status after ureteroscopy, allowing a higher SF rate when compared to PL. HUs may significantly influence this success rate.

We present a rare, but critical case of renal rupture after ureterorenoscopic holmium:YAG laser lithotripsy. This is the first case report of renal rupture after laser lithotripsy in managing an upper urinary tract stone. A 75-year-old male underwent retrograde ureterorenoscopic holmium:YAG laser lithotripsy for a left renal pelvic stone. A drop in blood pressure was noted postoperatively. Abdominal computed tomography confirmed a left subcapsular, perirenal hematoma and a stone which had dropped out to the left subcapsular space.

To evaluate the impact of age, stone size, location, radiolucency, extraction of stone fragments, size of ureteroscope and presence and degree of hydronephrosis on the efficacy and safety of holmium:YAG (Ho:YAG) laser lithotripsy in the ureteroscopic treatment of ureteral stones in children.Between October 2011 and May 2013, a total of 104 patients were managed using semirigid Ho:YAG ureterolithotripsy. Patient age, stone size and site, radiolucency, use of extraction devices, degree of hydronephrosis and size of ureteroscope were compared for operative time, success and complications.In all, 128 URS were done with a mean age of 4.7 years. The mean stones size was 11 mm. Success rate was 81.25 %. Causes of failure were 12.5 % access failure, 1.5 % extravasation and 4.7 % stone migration. Overall complications were 23.4 %. Failure of dilatation and extravasation were detected only in children2 years old. Extravasation was significantly higher in smaller ureters and cases with stone size15 mm. Stone migration was significantly higher in upper ureteric stones.Failure and complications rates in Ho:YAG ureterolithotripsy were significantly affected by younger age (2 years), upper ureteric stones and smaller ureters but were not related to stone radiolucency or degree of hydronephrosis. Larger stones (15 mm) were associated with increased complications. After multivariate analysis, the age of the patients remained significant predictor for failure of dilatation and stone migration, while size of the ureter was the only significant predicting factor for failure.

Objective: Prospective evaluation of the efficacy and safety of the extracorporeal shock wave lithotripsy (SWL) and ureteroscopy with Holmium: YAG laser lithotripsy (URSL) as a primary treatment for impacted stone in the proximal ureter. Patients and Methods: A total of 82 patients with a single impacted stone in the proximal ureter were included in the study. Patients were allocated into two groups according to patient preference for either procedure. The first group included 37 patients who were treated by SWL and the second group included 45 patients treated by URSL. The preoperative data and treatment outcomes of both procedures were compared and analyzed. Results: There was no difference as regards to patient and stone characters between the two groups. There was significantly higher mean session number and re-treatment rate in the SWL group in comparison to URSL group (1.5 ± 0.8 vs. 1.02 ± 0.15 session, and 43.2% vs. 2.2%, respectively). At one month, the stone-free rate of the URSL group was statistically significantly higher than that of the SWL group (80% vs. 67.6%, respectively). The stone-free rate at three months was still higher in the URSL group, but without statistically significant difference (80.2% vs. 78.4%, respectively). There was no statistically significant difference in the rate of complications between the SWL and URSL (24.3% vs. 15.6%, respectively). Conclusion: Both procedures can be used effectively and safely as a primary treatment for impacted stone in the proximal ureter; however, the URSL has a significantly higher initial stone-free rate and lower re-treatment rate.

OBJECTIVE We retrospectively compared the clinical outcomes of Lithoclast assisted lithotripsy (L group) with those of Holmium YAG laser assisted lithotripsy (H group). PATIENTS AND METHODS We analyzed records for operation time, duration of ureteral stenting, complication and stone-free rates in the L group (388 patients) and the H group (368 patients) for the primary procedure. RESULTS The stone locations (L group/H group) were U1 in 141/181, U2 in 69/57, and U3 in 178/130. Respective median stone sizes (L group/H group) were: U1,: 10.0/10.0 mm; U2,: 7.0/10.0 mm;, and U3,: 6.0/7.0 mm. Secondary procedures were performed in 79 L group patients and 35 H group patients. The median operation times (L group/H group) were 29.5/25.0 minutes. The median durations of ureteral stenting (L group/H group) were 4.0/4.0 days. The stone-free rates (L group/H group) according to the locations of the stones were 69.3/82.0% in U1, 85.5/87.0% in U2, and 92.0/98.4% in U3. Complications (L group/H group) were ureter perforation in 8/5 cases, pyelonephritis in 7/2 cases, ureteral stricture in 2/6 cases, and stone push up in 27/13 cases. CONCLUSION The operation time for holmium YAG laser assisted lithotripsy was significantly shorter than that of the Litoclast assisted procedure, and the stone-free rate with holmium YAG laser assisted lithotripsy was better than that with Lithoclast assisted lithotripsy for U1 and U3 stones.

Osteoma is one of the most common tumors of the cranial vault and the facial skeleton. For osteoma in the facial region, endoscopic resection is widely used to prevent surgical scarring. Tumors in a total of 14 patients were resected using an endoscopic holmium-doped yttrium aluminium garnet (Ho:YAG) laser with a long flexible fiber. Aside from having the advantage of not leaving a scar due to the use of endoscopy, this procedure allowed resection at any position, was minimally invasive, and caused less postoperative pain. This method yielded excellent cosmetic results, so the endoscopic Ho:YAG laser is expected to emerge as a good treatment option for osteoma.

Aim: To evaluate the effectiveness and safety of holmium:YAG (Ho:YAG) laser endopyelotomy in distinctive ureteropelvic junction obstructions (UPJO) with distinctive aetiologies. Material and methods: Thirty-one patients diagnosed with UPJO of distinctive causes were included. Aetiology consisted of 7 congenital UPJO, 10 post-pyeloplasty UPJO, 7 post-lithotomy obstructions, 4 ureteropelvic junction obstructions post-extracorporeal shockwave lithotripsy stenoses and 3 post-ureteroscopic lithotriptic UPJO. Retrograde ureteroscopic Ho:YAG laser endopyelotomy was performed in all patients. Operation related parameters were studied. Results: Average procedure duration was 46 min. Mean discharge was 1.81 days. There was no notable complication such as perforation or haemorrhage. All patients were followed for at least 12 months. The single success rate was 80.6%, leaving 6 patients undergoing secondary endopyelotomy, among whom 4 were successful while 2 required an open approach. The overall success rate was 93.5%. Failed pyeloplasty UPJO is more disposed to restenosis (p = 0.0075). Inversely implanted ureteral stent yielded a higher success rate (p = 0.0158). Conclusions: Ho:YAG laser endopyelotomy is a safe, minimally invasive approach effective in both primary and secondary UPJO treatments. Implantation of inversed ureteral stents can be more beneficial.

We prospectively analyzed and compared the effectiveness and complications of pneumatic lithotripter with a holmium:yttrium-aluminum-garnet (Ho:YAG) laser for the ureterorenoscopic management of impacted ureteral stones.From January 2006 to January 2008, we performed retrograde endoscopic treatment in 288 patients with ureteral stones in our clinic. The patients with impacted stones were randomized into two groups according to the lithotripter used to fragment the stone: pneumatic (n = 40) and laser (n = 40). The preoperative, operative, and post-operative follow-up findings were analyzed and compared.The average stone size was similar in both groups (118.8 ± 58.3 mm(2) vs. 110.7 ± 54.4 mm(2)). The calculi were located in the distal ureter in most of the patients in both groups (65% in pneumatic group and 52.5% in laser group). The operation time was significantly diminished in the laser group (P = 0.001). The stone-free rates after a single ureteroscopic procedure were 80 and 97.5% in the pneumatic and laser groups, respectively (P = 0.03). Auxiliary treatments were needed in seven patients in the pneumatic group, while only one patient in the laser group (P = 0.05) needed this treatment. After the additional procedures, a 100% success rate was achieved in both groups. The rate of double J stent insertion was significantly higher in the pneumatic group (P = 0.01). In the pneumatic group, four cases of stone up-migration and one case of post-operative stricture were seen, whereas only one case of stone up-migration was noted in the laser group.Our comparative study has shown that the use of Ho:YAG as an intracorporeal lithotripter during ureteroscopic management of impacted ureteral stones is highly efficient with high success rates, regardless of the stone location.

Single use and reusable variants of holmium:YAG laser fibers are available to treat calculi during ureteroscopic procedures. In this prospective, multicenter study we evaluated a series of reusable holmium:YAG laser optical fibers. We hypothesized that reusable fibers provide a cost advantage over single use variants.We prospectively recorded fiber data, including type, size, number of uses, laser pulse energy and frequency, and total energy delivered. All fibers were new and purchased off the shelf by staff at each institution. We performed a cost analysis comparing reusable fibers to single use variants.During 541 procedures a total of 37 holmium:YAG optical laser fibers were used, including 21 Laser Peripherals 270 (Laser Peripherals, Golden Valley, Minnesota), 7 Laser Peripherals 365, 4 Lumenis SlimLine™ 200 and 3 Lumenis SlimLine 365 fibers. After stratifying by core size 365 μm core fibers had significantly more uses than 270 μm core fibers (average 23.5 vs 11.3, p0.02). By fiber type the mean ± SE number of uses was 12.8 ± 2.44, 3 ± 0.4, 21.3 ± 7.12 and 28.7 ± 6.69 for the Laser Peripheral 270, Lumenis SlimLine 200, Laser Peripherals 365 and Lumenis SlimLine 365, respectively. The total cost savings for reusable fibers vs single use variants was $64,125.Reusable holmium:YAG optical laser fibers are a more cost-effective option than single use variants. Fibers with a 365 μm core provide more uses than smaller 270 μm variants.

症例は20歳，男性．完全内臓逆位併存先天性胆道拡張症に対する肝外胆管切除・肝管空腸吻合術後の肝内結石症に対し，ホルミウムヤグ（Ho:YAG）レーザーを用いた経皮経肝胆道鏡下砕石術を施行し，合併症無く完全砕石を行い得た．Ho:YAGレーザーは胆道結石破砕に際し，有効なエネルギーデバイスの一つであると考えられた．

Purpose: A review of the literature of studies reporting complications of ureteroscopic urinary tract stone ablation using the holmium:YAG laser was performed. Patients and methods: Electronic databases were searched using specific keywords to identify relevant studies. Reference lists of identified articles were scrutinised for other studies and searches were conducted using the names of authors known to have published widely in this field. Two reviewers assessed retrieved articles for inclusion criteria. Patients Results: Overall, 48 studies published between 1994 and 2007 were included. Half were published since 2000. In total, 4454 patients were identified. Around half of studies were performed in North America (25). The number of patients per study varied from 8 to 598. The study populations were very heterogeneous in terms of stone position and size, and ureteroscope size and rigidity. Overall, 303 (6.8%) complications were identified. Post-operative ureteric stricture and perforation rates were both 1.0%. There were only six major complications identified (0.1%). The post-operative sepsis rate was 2% and one death was reported. Conclusions: Upper urinary tract stone ablation using the holmium:YAG laser is both safe and reliable. Follow-up imaging to detect procedure-specific complications would not appear to be routinely indicated given this low complication rate.

Objectives To evaluate the modalities of electrocautery, holmium:yttrium-aluminum-garnet (YAG) laser, hydrodissection, and combined holmium:YAG laser with hydrodissection applied to laparoscopic partial nephrectomy (LPN) in a porcine model. Methods A total of 16 Yorkshire pigs were divided into 4 equal groups (electrocautery, hydrodissection, holmium:YAG laser, and combined hydrodissection/holmium:YAG laser) and underwent unilateral LPN. The total operative time, partial nephrectomy time, hemostasis modality, and intraoperative complications were recorded. The pre- and postoperative hemoglobin was measured. Abdominal computed tomography was performed 2 weeks postoperatively. Representative specimens from each arm were examined for histologic findings. Results The mean total operative time and the time to perform partial nephrectomy was lower for the combined hydrodissection/holmium:YAG laser arm (66 minutes and 13 minutes, respectively) compared with the electrocautery arm (93 and 30 minutes, respectively), holmium:YAG laser-only arm (77 and 19 minutes, respectively), and hydrodissection-only arm (129 and 35 minutes, respectively). The mean decrease in hemoglobin was the least for the combined hydrodissection/holmium:YAG laser arm (5.3 g/L) followed by the holmium:YAG-only (15.3 g/L), hydrodissection-only (16.8 g/L), and electrocautery (35.5 g/L) arms, respectively. The histologic examination demonstrated an increased depth of tissue injury in the electrocautery arm. Conclusions In a porcine model, the combined use of the hydrodissection/holmium:YAG laser to perform LPN had the shortest operative time and the lowest decrease in hemoglobin and appears to warrant additional clinical evaluation in human trials for LPN.

Study Type – Therapy (case series) Level of Evidence 4 OBJECTIVE To report our experience of treating patients with original and recurrent upper tract urothelial carcinomas (UC) using endoscopic lasers, with holmium-YAG and/or neodymium-YAG laser ablation, and for whom tumour stage and grade were obtained by endoscopic biopsy. PATIENTS AND METHODS From March 2003 to March 2007, 15 patients with upper tract UC were treated with endoscopic laser ablation as the primary management. Patients were followed up by intravenous urography, computed tomography, urine cytology and/or ureteroscopic surveillance at 3- to 12-month intervals. The median (range) follow-up was 25.5 (13–51) months. RESULTS Of the 15 patients, five had an upper tract recurrence during the follow-up. Three of these were treated with total nephroureterectomy and two had a progression in tumour stage or grade. Three patients had residual tumours; they were treated with repeated endoscopic laser treatments and had no recurrence over a median (range) of 24 (13–26) months. The renal preservation rate was 12/15 and the local recurrence rate was six/15 after the initial endoscopy. The median operative duration and tumour size were 60 min and 10 mm, respectively. CONCLUSION Patients with low-grade and -stage disease and normal contralateral kidneys also benefit from this approach, if there is an adequate endoscopic biopsy. As the operative duration tended to be associated with the maximum tumour size, this treatment is potentially available for a maximum tumour size of

Foreign bodies of the urinary tract represent a urologic emergency. First-line treatment is endoscopic removal, but this is often impeded by restricted space, especially in the urethra. We postulated that foreign objects could be fragmented by Holmium:YAG laser and investigated its effect on objects of varying composition.In a specially designed stage flushed with physiologic saline, medical and non-medical objects of differing composition and diameter were subjected to fragmentation by Holmium:YAG at powers of 18 and 30 W. In additional thermal experiments, 5,000 J was applied to differing volumes of 0.9% sodium chloride. Experiments were repeated ten times.With one exception (16 Ch silicon catheter) all medical objects were fragmented (latex urinary catheter, ureteral stents, and guidewires). Of non-medical objects (wood, steel, copper, graphite, and nylon) only copper wire was not amenable to laser dissection. These in vitro results were applied in two patients who presented with a pencil (wood and graphite) in the urethra or bladder. After Holmium:YAG laser fragmentation, the pencil could be removed by forceps each.Foreign objects in the urinary tract can be fragmented with a Holmium:YAG laser. When foreign bodies are too big for initial endoscopic extraction, the clinician should consider this technique as a reasonable and atraumatic option to avoid open surgery.

Background: Stone retropulsion during ureteroscopic lithotripsy leads to additional procedures for residual calculi. The Stone Cone (Boston Scientific, Natick, Mass., USA) is a device designed to prevent stone migration. Objective: To determine the incidence of calculus retropulsion and additional procedures after ureteroscopy with intracorporeal lithotripsy while using the Stone Cone. Materials and Methods: A retrospective review of patients with obstructing ureteral calculi who underwent ureteroscopy and holmium:YAG laser lithotripsy using the Stone Cone as a backstop over a 3-year period at an academic medical center was performed. 133 patients underwent ureteroscopy with holmium:YAG laser lithotripsy using the Stone Cone to prevent calculus retroplusion. Success was defined as no residual fragments >2 mm in size, no changes from semirigid to flexible ureteroscope, and no additional procedures. Post-operative imaging was abdominal plain radiography or computed tomography. A MEDLINE search was performed to indentify all English clinical studies of the Stone Cone. Results: Of the 133 uses of the Stone Cone, there were 2 (1.5%) residual retropulsed fragments >2 mm which required an additional procedure. There were no changes to flexible ureteroscope secondary to stone retropulsion in 105 cases of semirigid ureteroscopy. There was no instance of ureteral obstruction from residual 2-mm fragments. There were no ureteral strictures or hydronephrosis among 91 patients with long-term follow-up imaging. A review of the literature was performed which yielded 4 clinical publications and 90 reported cases using the Stone Cone with 100% success. Two of these studies showed statistically significant improvement when compared with control patients. Conclusions: The Stone Cone minimized stone retropulsion during ureteroscopic laser lithotripsy. The Stone Cone offers the urologist greater certainty during ureteroscopy and may decrease the number of clinically significant residual calculi.

Percutaneous nephrolithotomy (PCNL) is a well established procedure and accepted as the standard of care for the treatment of large renal calculi. Since the introduction of the holmium:yttrium-aluminum-garnet (Ho:YAG) laser into clinical practice in 1990, it has been used successfully to treat various urologic conditions. Today it is the modality of choice for retrograde intracorporeal stone disintegration ureteroscopically, and has also been used successfully for PCNL. One disadvantage when using the Ho:YAG laser for disintegration of renal calculi is the need for graspers to extract fragments and the mobilization of fragments due to the lack of simultaneous suction. We present our experience with a Ho:YAG laser in combination with simultaneous suction in an in-vitro model using a new endourologic technique in comparison to conventional ultrasonic lithotripsy.

To demonstrate the validity of non-contact holmium:yttrium-aluminum-garnet laser stone fragmentation in an in-vitro model and to characterize the optimal laser settings to perform this technique.A caliceal model consisting of a glass test tube filled with 0.9% normal saline was created. Into this system, a 365-mum laser fiber was inserted after stabilization 2 mm above the surface of the stones. Laser experiments were conducted using tubes that contained four soda limestone phantoms with a total stone burden of approximately 0.2 g per tube. The laser energy was varied between 1.0 and 1.5 J, with a firing frequency of 20, 30, or 40 Hz. Ten tubes were tested at each setting combination for a duration of 2 minutes. Thus, 60 tubes were tested. The contents of each tube were filtered through a 2-mm sieve after treatment, and all remaining fragments were dried for 5 days. The fragments were weighed, and the difference from pretreatment was calculated. Differences in weights and laser settings were compared using one-tailed and two-sample t testing.Each experiment resulted in a significant decrease in stone burden from prelaser weight (all P values = 0.00). Laser settings were manipulated between combinations of 1.0 J at a frequency of 20, 30, and 40 Hz, and an energy of 1.5 J and 20, 30, and 40 Hz. This resulted in a respective mean weight loss of -42%, -58%, and -47% at 1.0 J, and -24%, -56%, and -63% at 1.5 J. The t tests were performed to detect differences between weight loss and to determine the optimal settings. Laser settings of 1.5 J and 40 Hz for 2 minutes produced the greatest mean decrease in stone burden (63%). This loss was significantly different from that of all settings at 1.0 J and the setting of 1.5 and 20 Hz (P0.05). The mean percentage weight loss for each setting was then normalized to the total energy used. Settings of 1.0 J and 20 Hz were the most efficient, with a change in weight of -18% per kJ.We duplicated the "popcorn effect" of non-contact laser use in vitro. In this model, the technique results in a significant decrease in stone burden (up to 63%) in just 2 minutes. Adequate energy and high frequency seemed to optimize the effectiveness of the method, but excessive energy and frequency produced diminishing returns.