YAG Laser Lithotripsy Research Articles

1277 IN VITRO EFFICACY OF HOLMIUM:YAG LASER LITHOTRIPSY IN NON FLOATING STONES. - EFFECT OF PULSE FREQUENCY, ENERGY AND LENGTH -

You have accessJournal of UrologyTechnology & Instruments: Ureteroscopy1 Apr 20101277 IN VITRO EFFICACY OF HOLMIUM:YAG LASER LITHOTRIPSY IN NON FLOATING STONES. - EFFECT OF PULSE FREQUENCY, ENERGY AND LENGTH - Felix Wezel, Christoph Hammes, Axel Haecker, Patrick Krombach, Maurice Stephan Michel, and Thorsten Bach Felix WezelFelix Wezel More articles by this author , Christoph HammesChristoph Hammes More articles by this author , Axel HaeckerAxel Haecker More articles by this author , Patrick KrombachPatrick Krombach More articles by this author , Maurice Stephan MichelMaurice Stephan Michel More articles by this author , and Thorsten BachThorsten Bach More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2010.02.848AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Holmium:YAG (Ho:Yag) laser lithotripsy is the gold standard in endoscopic stone treatment. Aim of this study was to evaluate the influence of pulse frequency, power and length on the effectiveness of Ho:Yag laser lithotripsy using two different artificial stone compositions in-vitro. METHODS Three different Ho:Yag laser devices (Sphinx, RevolixDuo (both LisaLaser, Germany) and Odyssey 30 (Cook, Ireland) were tested. The devices were used at different pulse energy rates (1 and 2 Joule) and frequency settings (5 and 10 Hz) all resulting in an output power of 10W, respectively. Where possible (Sphinx and Odyssey 30), pulse length was modified (350 vs. 700 msec). The light was transmitted via flexible 365μm fibers. Experiments were performed in a water bath using cone shaped artificial stone (20ml volume) consisting of a soft stone composition (plaster of paris; Quick-mix, Germany) and a hard stone composition (Fujirock type 4 dental stone; GC Europe, Belgium). Lithotripsy was performed for 60 sec in contact mode on fixed stones applying 600 W in total per setting. Stones were dried for 72 h; fine granulated sand was used to measure the volume of the craters. Sample size was n=10 for all settings using hard stones, and n=6 when using soft stones. Unpaired t-test was used for statistical analysis. RESULTS In all of the 5 tested groups per stone type, a slower pulse rate but increased pulse energy (5 Hz/ 2 J vs. 10 Hz/1 J) resulted in a higher stone disintegration. At 5 Hz/ 2 J Ho:Yag laser lithotripsy was more effective applied on hard stones (+ 27.46% (10-55.4%); all p < 0.05) and on soft stones (+ 33.62% (8-54.3%); 3 of 5 tested groups p < 0.05) compared to the 10 Hz/ 1 J setting. Furthermore, reduction of the pulse length from 700 to 350 msec resulted in a significantly higher stone disintegration (+ 71.58% (57-120.6%); all p < 0.05) in soft stone composition in 4 tested groups. In hard stone composition, reducing the pulse length was associated with a significant higher stone disintegration (+ 27.25% (23.8-30.7%); all p < 0.05) in combination with higher pulse energy (2 J/ 5 Hz). At lower pulse energy (1 J/ 10 Hz), the increased stone disintegration rate was not significant (+ 6,5% (6.4-6.5%), p > 0.05, respectively). CONCLUSIONS Our results indicate that higher pulse energy and shorter pulse length increase disintegration rates of Holmium:YAG laser lithotripsy when retropulsion is excluded in vitro. This may help to improve efficacy of Holmium:YAG laser lithotripsy in non floating stones in vivo. Mannheim, Germany© 2010 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 183Issue 4SApril 2010Page: e495 Advertisement Copyright & Permissions© 2010 by American Urological Association Education and Research, Inc.MetricsAuthor Information Felix Wezel More articles by this author Christoph Hammes More articles by this author Axel Haecker More articles by this author Patrick Krombach More articles by this author Maurice Stephan Michel More articles by this author Thorsten Bach More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

SWL is More Cost-Effective than Ureteroscopy and Holmium:YAG Laser Lithotripsy for Ureteric Stones: A Comparative Analysis for a Tertiary Referral Centre

Background: To identify the most cost-effective treatment for ureteric stones ≤15 mm in our department, by using an economic model to compare the total cost of shockwave lithotripsy (SWL) versus ureteroscopy with Holmium:YAG laser lithotripsy (URSL). Patients and methods: Data for patients treated with the same lithotriptor were retrospectively analyzed. The financial department provided data about the cost of procedures. This model accepted a 100% stone-free rate for URSL in outpatients, and a 50% rate of insertion of a ureteric stent. The cost for each procedure to render a patient stone-free was estimated by the following equations: costSWL = cost(initial SWL session) + [cost(SWL session) × retreatment rate] + [cost(URSL) × SWL failure rate] + [cost(stent insertion and removal) × rate] + [cost(KUB film) × 4] costURSL = cost(URSL) + [cost(stent removal) × 50%] + [cost(KUB film) × 2] Results: Records of 228 patients with previously untreated solitary radiopaque ureteric stones ≤15 mm were reviewed. The total cost for SWL (cSWL) was £1491/patient, while the total cost for URSL (cURSL) was £2195/patient. The difference was highest in the upper ureter (over £1000), and lowest in the distal part (URSL about 40% more expensive). For lower ureteric stones &gt;10 mm, SWL was over £500 more expensive than URSL. Conclusion: Using data from the department to calculate cost-effectiveness for ureteric stones ≤15 mm a difference in favour of SWL versus URSL was found. Uniform guidelines incorporating cost are impossible considering differences between countries; each centre should probably assess their data individually.

Thulium fiber laser lithotripsy using tapered fibers

The Thulium fiber laser has recently been tested as a potential alternative to the Holmium:YAG laser for lithotripsy. This study explores use of a short taper for expanding the Thulium fiber laser beam at the distal tip of a small-core fiber. Thulium fiber laser radiation with a wavelength of 1,908 nm, 10 Hz pulse rate, 70 mJ pulse energy, and 1-millisecond pulse duration was delivered through a 2-m-length fiber with 150-microm-core-input-end, 300-microm-core-output-end, and 5-mm-length taper, in contact with human uric acid (UA) and calcium oxalate monohydrate (COM) stones, ex vivo (n = 10 each). Stone mass loss, stone crater depths, fiber transmission losses, fiber burn-back, irrigation rates, and deflection through a flexible ureteroscope were measured for the tapered fiber and compared with conventional fibers. After delivery of 1,800 pulses through the tapered fiber, mass loss measured 12.7+/-2.6 mg for UA and 7.2+/-0.8 mg COM stones, comparable to conventional 100-microm-core fibers (12.6+/-2.5 mg for UA and 6.8+/-1.7 mg for COM stones). No transmission losses or burn-back occurred for the tapered fiber after 36,000 pulses, while a conventional 150-microm fiber experienced significant tip degradation after only 1,800 pulses. High irrigation rates were measured with the tapered fiber inserted through the working port of a flexible ureteroscope without hindering its deflection, mimicking that of a conventional 150 microm fiber. The short tapered distal fiber tip allows expansion of the laser beam, resulting in decreased fiber tip damage compared to conventional small-core fibers, without compromising fiber bending, stone vaporization efficiency, or irrigation rates.

Management of ureteric stone in pediatric patients

The management of ureteral stones in children is becoming more similar to that in adults. A number of factors must be taken into account when selecting one's choice of therapy for ureteral stone in children such as the size of the stone, its location, its composition, and urinary tract anatomy. Endoscopic lithotripsy in children has gradually become a major technique for the treatment of ureteral stones. The stone-free rate following urteroscopic lithotripsy for ureteral stones has been reported in as high as 98.5-100%. The safety and efficacy of Holmium:YAG laser lithotripsy make it the intracorporeal lithotriptor of choice. Given its minimally invasive features, extracorporeal shock wave lithotripsy (ESWL) has become a primary mode of treatment for the pediatric patients with reno-ureteral stones. Stone-free rates have been reported from 59% to 91% although some patients will require more than one treatment session for stone clearance. It appears that the first-line of therapy in the child with distal and mid-ureteral stones should be ureteroscopic lithotripsy. While ESWL is still widely considered the first-line therapy for proximal ureteral calculi, there is an increasing body of evidence that shows that endoscopic or ESWL are equally safe and efficacious in those clinical scenarios. Familiarity with the full spectrum of endourological techniques facilitates a minimally invasive approach to pediatric ureteral stones.

Laser-induced lithotripsy and photodynamic therapy in urology – A short introduction to current laser applications

Abstract Laser-induced lithotripsy and photodynamic therapy (PDT) are among the most important laser applications in urology. Laser lithotripsy has revolutionized urinary calculi treatment. Today, Ho:YAG laser lithotripsy using a small-caliber ureteroscope can be considered to be the first choice for treatment of ureteral calculi. In contrast to laser-induced lithotripsy, PDT is not yet firmly established in urological clinical routine. However, preclinical and clinical trials with PDT in urology are showing promise in the treatment of malignancies at multiple sites. The present article gives a review of the literature from both fields and discusses the current status of laser lithotripsy and PDT in urology.

MP-08.12: Holmium: YAG Laser Lithotripsy with Semirigid Ureterorenoscope for Treatment of Ureteral Calculi: Report of 1398 Cases

MP-08.12: Holmium: YAG Laser Lithotripsy with Semirigid Ureterorenoscope for Treatment of Ureteral Calculi: Report of 1398 Cases

MP-08.11: Flexible Ureteroscopy with Holmium: YAG Laser Lithotripsy for Treatment of Renal Stones

MP-08.11: Flexible Ureteroscopy with Holmium: YAG Laser Lithotripsy for Treatment of Renal Stones

Treatment of ureteric lithiasis with retrograde ureteroscopy and holmium:YAG laser lithotripsy vs extracorporeal lithotripsy

To analyse the efficiency of extracorporeal shockwave lithotripsy (ESWL) vs retrograde ureteroscopy and holmium:YAG laser lithotripsy, as ESWL is successful in 67-90% of cases but endoscopic lithotripsy with pneumatic lithotrites or lasers is successful in 90-96% of distal ureteric calculi, and holmium:YAG lithotripsy is effective in proximal ureteric calculi. From April 2006 to April 2008 we assessed 164 patients undergoing ureteric lithiasis in two homogeneous groups: group A included 83 treated with retrograde ureteroscopy and holmium:YAG endoscopic lithotripsy, and group B, 81 treated by ESWL. For laser lithotripsy we used 2071 mJ pulses at 3-6 Hz, with a mean of 1105 pulses and 2.5 kJ of total energy. ESWL was carried out using 37.5-87.5 mJ shock waves, a mean of 3650 shock waves and 187.6 J, with a radioscopy time of 1-4 min. The results were assessed after 3 weeks with plain films and ultrasonography, or urography. The efficiency of each procedure was assessed by calculating the relative risk, and results compared using the chi-square or Student's t-test. The efficiency quotient (EQ) was determined for both procedures, and the focal applied energy quotient (FAEQ) used to assess ESWL. The overall success rate for retrograde ureteroscopy and laser lithotripsy was 96.4% (80/83 patients), with an EQ of 0.52; a JJ catheter was placed in 67 patients. The success rate for the first ESWL session was 48%, and after repeat ESWL was 64% (52/81 patients), giving an EQ of 0.39. For successful treatments the FAEQ was 9.22, vs 6.47 for the failures (P < 0.005). There was a significant difference (P < 0.001) favouring laser lithotripsy, with an absolute benefit of 46% (95% confidence interval 33.8-57.9%), and number needed to treat of 2 (2-3), but no significant differences for lumbar ureteric calculi. Endoscopic lithotripsy with the holmium laser is more effective than ESWL, but for lumbar ureteric calculi ESWL is therapeutically recommended as it is less invasive.

Holmium:YAG Laser Lithotripsy for Urolithiasis in Horses

Laser lithotripsy has been used as an alternative to surgical removal of uroliths. To describe the procedure and efficacy of laser lithotripsy for removal of lower urinary tract uroliths in horses. Additionally, the ultrastructure and the differences in mineralogy and microstructure from 1 successful and 1 unsuccessful laser lithotripsy case are described. Six client-owned horses with 7 episodes of naturally occurring urocystoliths, urethroliths, or both. Retrospective study of all horses treated between 2006 and 2008 by laser lithotripsy. All horses were sedated followed by laser lithotripsy. Quantitative urolith analysis was performed in all cases. Ultrastructure and microstructure analyses were performed on uroliths from 2 horses. Procedural success was achieved in 5 of 7 laser lithotripsy procedures. No complications occurred as a result of laser lithotripsy. One horse developed uroabdomen likely as a result of manual lithotrite disruption of the bladder after failure of laser lithotripsy. There were differences in microstructure between 1 urolith that was successfully fragmented by laser lithotripsy and 1 urolith that was resistant to laser fragmentation. Laser lithotripsy is an effective procedure for removal of some urocystoliths, urethroliths, or both in horses.

S112 Comparative evaluation of pneumatic versus holmium: YAG laser lithotripsy for impacted ureteral stones

S112 Comparative evaluation of pneumatic versus holmium: YAG laser lithotripsy for impacted ureteral stones

Use of the Stone Cone for Prevention of Calculus Retropulsion during Holmium:YAG Laser Lithotripsy: Case Series and Review of the Literature

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.

Endoscopic management of paediatric ureteric calculi by holmium:yag laser lithotripsy

Purpose To determine the efficacy and safety of ureterorenoscopic Holmium:YAG lithotripsy for ureteric stone in children. Material and Methods Records of 186 children with ureteral calculi managed with ureterorenoscopic Holmium:YAG lithotripsy were reviewed between July 2005 and December 2007. Patient records were reviewed for age, sex, stone laterality, location, number and size, need for ureteral stenting and complications in perioperative period and follow up. Paediatric cystoscope(miniscope) size 6/7.6 ch, ureterorenoscopes sizes 6/7.5 ch and 7.8/9 ch were used according to the size of patient and site of stone. Results Of the 186 children, 71 were female and 115 were male. Mean age was 6.1 years (age range 9months-14 years). There was no significant difference in stone laterality (eighty four left, ninety four right and eight bilateral ureteral stones). Main presenting symptoms were renal colic, hematuria and urinary tract infection or a combination of these symptoms. DJ stents were placed at the conclusion of the procedure in 54 patients while ureteral catheter was retained in rest of the cases for 24 to 48 hours. The procedure was carried in the same session for bilateral stones in eight patients. Additional procedure include PCNL in 12 and cystolithoclast in 5 cases for associated renal and bladder calculi respectively. Complete stone clearance was achieved at the end of the treatment in all patients (success rate 100%). Complications encountered during the procedure include extravasation of irrigant in 5 patients, required ultrasound guided placement of drain and per cutaneous nephrostomy in 2 patients for transient obstructive hydronephrosis. Other complications include mild haemeturia and urinary tract infection. Conclusions This study confirms the effectiveness and safety of ureterorenoscopy and holmium laser in the treatment of ureteral stones in children regardless of stone location.

Holmium-YAG Laser Lithotripsy in the Treatment of Difficult Biliary Stones Utilizing Peroral Single Operator Cholangioscopy (SPYGLASS): A Multi-Center Experience

5-10% of biliary stones are not amenable to standard endoscopic extraction techniques. Electrohydraulic and laser lithotripsy have been shown to be very effective in this setting but have been utilized sparingly. The recent development of single operator steerable cholangioscopy (SpyGlass, Boston Scientific, Natick, MA) now permits for routine use of these technologies. We report our multi-center cumulative experience of using Holmium:YAG laser lithotripsy with SpyGlass cholangioscopy in the management of difficult intraductal biliary stones. METHODS Patients presenting with refractory bile ducts stones underwent ERCP with SpyGlass and Holmium:YAG lithotripsy using a SlimLine GI disposable laser probe (Lumenis, Santa Clara, CA). ERCP with SpyGlass was performed in the standard fashion. Once the stones were visually identified, the laser probe was placed in very close proximity to the stone and short bursts (< 5 sec) of energy (8-12 Watts) were applied until adequate fragmentation was achieved. Repeat ERCP sessions were performed as needed to achieve complete stone clearance. Safety and efficacy parameters were retrospectively collected utilizing a standardized data collection form.

Holmium: YAG Laser Safety Data On Bile Duct Epithelium in the Porcine Model

Background: Laser therapy has been increasing used for gastrointestinal and urological applications. Due to a very short wavelength, holmium: YAG can generate high-energy focused shock waves while reducing surrounding thermal injury. This characteristic has led to recent interest in using this technology for the fragmentation of large bile duct stones that have been refractory to conventional endoscopic therapy. Aim: The aim of this study was to establish safety data for holmium: YAG laser lithotripsy within the bile duct in the porcine model. Methods: 6 female 50 kg domestic pigs underwent necropsy and the bile ducts were explanted. The bile ducts were excised longitudinally exposing the epithelial surface and submerged under tension in liquid media. A Slimline holmium YAG laser probe (Lumenis, Sunnyvale, CA) was placed in perpendicular contact with the bile duct epithelium and activated at various energy density settings to evaluate perforation rates. The power density settings ranged from 8 to 15 watts (W) and were accomplished using various combinations of frequencies (Hz) and joules (J). The laser was activated until perforation of the bile duct occurred or for a maximum of 60 seconds. For each setting the probe was placed in similar locations on both the proximal and distal aspects of the duct. Both location and wattage were randomized to avoid physiologic differences that may affect outcomes. The median perforation times at each power setting were then compared using the Kruskal-Wallis One Analysis of Variance. Results: 104 data points were collected from 6 porcine bile ducts using 6 different power settings: 8 W (n=22); 9 W (n=22); 10 W (n=16); 12 W (n=20); 14 W (n=8); 15 W (n=16). The median perforation times were: 8 W (60 s); 9 W (24.5 s); 10 W (28 s); 12 W (24.5 s); 14 W (14 s); 15 W (5 s). Pairwise multiple comparison (Dunn's Method) revealed statistically significant differences (P<0.05) in the perforation times between the following settings: 8 W vs 15 W; 9 W vs 15 W; 10 W vs 15 W; 12 W vs 15 W. Conclusions: Holmium: YAG laser appears to be safe when used in short bursts (< 5 sec) at power settings ranging from 8 W to 12 W. Further studies are required to determine the ideal power settings balancing effective stone fragmentation and perforation risk.

Ureteroscopy for treatment of ureteral calculi in children

Objective To evaluate the efficacy and safety of rigid ureteroscopy and Holmium:YAG laser lithotripsy for the treatment of ureteral calculi in children.

Impact of obesity on ureteroscopic laser lithotripsy of urinary tract calculi

The treatment of urinary tract stones in obese patients may differ from the treatment of non-obese patients and their success rate varies. Our objective was to compare ureteroscopic treatment outcomes of ureteral and renal stones, stratified for stone size and location, between overweight, obese and non-obese patients. Charts were reviewed for 500 consecutive patients presenting at our institution for renal and ureteral stones. A total of 107 patients underwent flexible or semi-rigid ureteroscopy with Ho:YAG laser lithotripsy and met criteria for review and analysis. Overall, initial stone-free rates were 91%, 97%, and 94% in normal, overweight and obese individuals respectively. When compared to non-obese patients, there were no significant differences (p value = 0.26; 0.50). For renal and proximal ureteral stones, the stone-free rate in overweight and obese individuals was 94% in both groups; and a stone-free rate of 100% was found for distal stones, also in both groups. Ureteroscopic treatment of stones in obese and overweight patients is an acceptable treatment modality, with success rates similar to non-obese patients.

Ureteroscopic management of distal ureteral stones in children: holmium: YAG laser vs. pneumatic lithotripsy

Aim: In this retrospective study, we aimed to compare the treatment results of pneumatic and holmium laser-assisted ureteroscopy in managing distal ureteral calculi in children. Materials and methods: The study group included a total of 36 children (23 boys, 13 girls) who underwent ureteroscopy between June 1998 and April 2008 due to distal ureteral calculi. Pneumatic lithotripsy was performed in 11 children and holmium:YAG laser lithotripsy in 25. Results: Their ages ranged from 18 months to 14 years (mean: 8.5 ± 3.5 years). The overall success rate for the holmium:YAG laser lithotripsy (100%) was higher than that of pneumatic lithotripsy (81.8%), but the difference was insignificant (P = 0.087). The complication rate was higher in pneumatic lithotripsy than in holmium:YAG laser lithotripsy (36.4% versus 4%, P = 0.023). Treatment time and hospital stay were shorter in the holmium:YAG laser lithotripsy group than in the pneumatic lithotripsy group (32.4 min versus 42.3 min, P = 0.041; 17.4 h versus 33.6 h, P = 0.013, respectively). Conclusion: This study showed that the success rate for holmium:YAG laser lithotripsy was almost identical with that achieved by pneumatic lithotripsy in the treatment of distal ureteral stones; ureteroscopic holmium:YAG laser lithotripsy had significant clinical advantages over pneumatic lithotripsy in terms of operative time, and hospitalization duration, stent requirements, and complication rates.

Ureteroscopy and Holmium: YAG Laser Lithotripsy as Emergency Treatment for Acute Renal Failure Caused by Impacted Ureteral Calculi

To present our clinical outcomes in managing acute renal failure caused by impacted ureteral calculi with ureteroscopy and holmium: yttrium-aluminum-garnet laser lithotripsy as emergency treatment. A series of 27 patients with acute postrenal failure were treated from November 2002 to December 2005. Impacted calculi were located in bilateral ureters in 22 patients and unilateral ureters in 5 patients with a solitary or single functioning kidney. Acute renal failure was demonstrated with oliguria or anuria and a significant increase in serum creatinine and blood urea nitrogen. Patients were treated emergently with ureteroscopy and holmium:yttrium-aluminum-garnet laser lithotripsy in the hospital within 24 hours. Ureteral stenting was performed in all cases. Postoperative renal function, electrolytes, and urine volume were monitored daily for 7 days. Radiography and/or ultrasonography were performed at a follow-up visit in 4 weeks. Ureteroscopy and laser lithotripsy were successfully performed in all patients. The mean operative time was 29.2 minutes (range 15-60). The successful fragmentation rate in the ureteroscopic procedure was 93.9% (46 of 49), and the overall stone-free rate was 88.9% (24 of 27). Shock wave lithotripsy was used in 3 patients after recovery of renal function. Of the 27 patients, 26 (96.3%) returned to normal renal function within 7 days. One patient (3.7%) had significant improvement of renal function, but it had not returned to normal at 12 weeks of follow-up. No intraoperative complications or postoperative ureteral stricture occurred. Emergency ureteroscopy and holmium: yttrium-aluminum-garnet laser lithotripsy can be safely and successfully performed by skilled endourologists for acute renal failure caused by impacted ureteral calculi.

Retrograde Holmium:YAG Laser Disintegration of Stones in Pelvic Ectopic Kidneys: Would It Minimize the Risk of Surgery?

To study the safety and efficacy of the holmium:YAG laser for disintegration of stones in pelvic ectopic kidneys. Between October 2005 and October 2006 four consecutive patients with large obstructing calculi (>3 cm in diameter) in the pelves of pelvic ectopic kidneys were prepared to be treated using retrograde ureterorenoscopy and holmium:YAG laser lithotripsy. All the patients were investigated with x-rays of the kidney, ureters, and bladder (KUB) and intravenous urography (IVU). Holmium:YAG laser lithotripsy was performed in a retrograde manner using energy ranging from 1 to 1.5 J/pulse with a frequency ranging from 15 to 20 Hz. Four patients were included in the study. The average age of the patients was 44 years (range 35-56 years). The average operative time for the laser lithotripsy procedure was 120 minutes (range 100-180 minutes). Three of the patients (75%) were rendered stone-free at 3 months. None of the patients developed back-pressure changes, gross hematuria, or abdominal pain during the follow-up period. One of the patients could not be treated endoscopically and required open surgery. Hospital stay ranged between 2 and 3 days. Retrograde ureteroscopy and holmium:YAG laser lithotripsy is efficacious for managing patients with stones in pelvic kidneys. The procedure is safe and effective and avoids the complications of open surgery.

Treatment of Large Impacted Proximal Ureteral Stones: Randomized Comparison of Percutaneous Antegrade Ureterolithotripsy versus Retrograde Ureterolithotripsy

We compared the safety and efficacy of percutaneous antegrade ureterolithotripsy with retrograde ureterolithotripsy for large impacted proximal ureter stones in a prospective randomized manner. A total of 91 patients with large impacted proximal ureteral stones, defined as stones >1 cm in size located between the ureteropelvic junction and the lower border of the fourth lumbar vertebra, were prospectively randomized for antegrade (44) or retrograde (47) ureterolithotripsy. Failure of the procedure (conversion to an open procedure), intraoperative and postoperative morbidity, operative time, hospital stay, stone clearance at discharge home, and follow-up were analyzed in each group. The main complications were bleeding (2.3%; 1 of 43) for the antegrade procedure and ureteral injury (2.3%; 1 of 44) for the retrograde procedure. Percutaneous antegrade ureterolithotripsy was associated with longer operative times (75.4+/-11.8 v 30.6+/-7.8 minutes; P<0.001), longer hospital stay (6.3+/-0.5 v 2.1+/-0.4 days; P<0.001), and a longer interval to return to normal activities (7.8+/-0.7 v 2.7+/-0.6 days; P<0.001). Nevertheless, the percutaneous antegrade procedure had a higher stone-free rate both at discharge home (95.3% v 79.5%; P=0.027), and 1 month post-procedure (100% v 86.4%; P=0.026). Percutaneous antegrade ureterolithotripsy is a valuable treatment modality for impacted proximal ureteral calculi larger than 1 cm, and achieves higher stone-free rates than those of retrograde ureteroscopy with holmium:YAG laser lithotripsy. The drawbacks of the antegrade procedure are longer operative time and hospital stay.