Comparison of ureteroscopic pneumatic lithotripsy and extracorporeal shock wave lithotripsy for the management of proximal ureteral stones: A single center experience.

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Iqbal, Nadeem; Malik, Yashfeen; Nadeem, Utbah; Khalid, Maham; Pirzada, Amna; Majeed, Mehr; Malik, Hajra Arshad; Akhter, Saeed

2018-05-01

To evaluate and compare the effectiveness of ureteroscopic (URS) pneumatic lithotripsy versus extracorporeal shock wave lithotripsy (ESWL) in the management of the proximal ureteral stones in terms of stone- free rates, complications and costs involved. We included 200 patients in Group 1 who underwent ESWL and 200 patients in Group 2 who underwent URS intervention. We used Modulith SL X lithotripter 3 rd generation Storz medical for ESWL group while Swiss pneumatic lithoclast was used to break the stone in the URS group. Stone-free status was defined as stone fragment of less than 4 mm on follow- up kidney ureter and bladder X-ray after 3 months of procedure. SPSS version 16 was used for statistical analysis. The mean age in ESWL and URS groups were 39.21±13.36, and 43.13±13.65 years respectively. Mean stone size was 10.47±3.7 mm (ESWL) and 13.6±6.6 mm (URS). Stone- free rate after single procedure was (125/200 patients) 62.5% for ESWL and (168/200 patients) 84% for URS group (p=0.001). Complications included post procedure sepsis in 3 (1.5%) patient of ESWL, while 7 (3.5%) patients of URS groups. Steinstrasse was seen in 4 (2%) patients of ESWL group. No mortality was seen in both groups. Mean costs for ESWL were US $320±50 while US $1100±150 for URS group (p=0.001). The stone-free rates after single procedure were significantly higher for the URS group while the complication rates were comparable in both groups. Treatment costs were significantly lower for the ESWL group.

The steinstrasse : A legacy of extracorporeal lithotripsy

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Mufti Mahmood

2003-01-01

Conclusions: Large stone burden (>2 cm and use of high energies (>16 kv are leading factors responsible for the development of steinstrasse. Ureteroscopic removal using pneumatic lithotripsy is a definitive and predictable treatment modality with a high success rate.

Management of calculus anuria using ureteroscopic lithotripsy as a first line treatment: its efficacy and safety.

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Savić, Slaviša; Vukotić, Vinka; Lazić, Miodrag; Savić, Nataša

2014-05-06

To present our experience with emergency ureteroscopic lithotripsy (URSL) for ureteral calculi associated with acute kidney injury (AKI). We retrospectively evaluated the 61 patients consisted of 90 ureteral units (UU), who underwent URSL. The cause of anuria was bilateral calculus obstructions in 29 cases, and unilateral calculus obstruction with, absent, nephrectomized contralateral kidney in 32 cases. In the case of bilateral synchronous ureteric calculi same-session bilateral ureteroscopy (SBBU) was done. The duration of anuria varied between 12 to 72 hours. At the end of the procedure, ureteral stent was systematically left in place in all patients. Surgery was performed 6-12 hours after admission to hospital. Patients were followed at least 1 month postoperatively. The stone free rates (SFR) were determined as baseline, on the first post-operative day, and as overall on the 30 days after procedure. The greatest success was achieved in the distal localization of stones up to 10 mm (93%). Renal function returned in 51 (83.6%) patients within 7 days. In 18 (29.5%) patients [18 (20%) UU] we performed second procedure as extracorporeal shockwave lithotripsy in 16.7% and open surgery in 2.2%. In 43 (70.5%) patients URSL was a successful therapeutic approach in dealing with pain, obstruction and calculus. Calculus anuria is a medical emergency that requires rapid diagnosis and prompt treatment for the purpose of decompression. URSL is the proper method of choice for selected patients and can be performed safely and has high success rates with minimal morbidity.

Retrograde Ureteroscopic Management of Large Renal Calculi: A Single Institutional Experience and Concise Literature Review.

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Scotland, Kymora B; Rudnick, Benjamin; Healy, Kelly A; Hubosky, Scott G; Bagley, Demetrius H

2018-06-06

Advances in flexible ureteroscope design and accessory instrumentation have allowed for more challenging cases to be treated ureteroscopically. Here, we evaluate our experience with ureteroscopy (URS) for the management of large renal calculi (≥2 cm) and provide a concise review of recent reports. A retrospective review was undertaken of all URS cases between 2004 and 2014 performed by the endourologic team at a single academic tertiary care institution. We identified patients with at least one stone ≥2 cm managed with retrograde URS. Stone size was defined as the largest linear diameter of the index stone. Small diameter flexible ureteroscopes were used primarily with holmium laser. Patient demographics, intraoperative data, and postoperative outcomes were evaluated. We evaluated 167 consecutive patients who underwent URS for large renal stones ≥2 cm. The initial reason for choosing URS included patient preference (29.5%), failure of other therapies (8.2%), anatomic considerations/body habitus (30.3%), and comorbidities (28.8%). Mean patient age was 55.5 years (22-84). The mean stone size was 2.75 cm with mean number of procedures per patient of 1.65 (1-6). The single session stone-free rate was 57.1%, two-stage procedure stone-free rate was 90.2% and three-stage stone-free rate was 94.0%. Access sheaths were used in 47% of patients. An association was identified between stone size and patient outcomes; smaller stones correlated with decreased number of procedures. Postoperative complications were minor. Single or multi-stage retrograde ureteroscopic lithotripsy is a safe and effective mode of surgical management of large renal calculi. Total stone burden is a reliable predictor of the need for a staged procedure and of stone-free rate.

Initial Clinical Experience with a Modulated Holmium Laser Pulse—Moses Technology: Does It Enhance Laser Lithotripsy Efficacy?

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Michael Mullerad

2017-10-01

Full Text Available Objective The Lumenis® High-power Holmium Laser (120H has a unique modulated pulse mode, Moses™ technology. Moses technology modulates the laser pulse to separate the water (vapor bubble, then deliver the remaining energy through the bubble. Proprietary laser fibers were designed for the Moses technology. Our aim was to compare stone lithotripsy with and without the Moses technology. Methods We designed a questionnaire for the urologist to fill immediately after each ureteroscopy in which the Lumenis 120H was used. We compared procedures with (n=23 and without (n=11 the use of Moses technology. Surgeons ranked the Moses technology in 23 procedures, in comparison to regular lithotripsy (worse, equivalent, better, much better. Laser working time and energy use were collected from the Lumenis 120H log. Results During 4 months, five urologists used the Lumenis 120H in 34 ureteroscopy procedures (19 kidney stones, 15 ureteral stones; 22 procedures with a flexible ureteroscope, and 12 with a semi-rigid ureteroscope. Three urologists ranked Moses technology as much better or better in 17 procedures. In 2 cases, it was ranked equivalent, and in 4 cases ranking was not done. Overall, laser lithotripsy with Moses technology utilized laser energy in less time to achieve a satisfying stone fragmentation rate of 95.8 mm3/min versus 58.1 mm3/min, P=0.19. However, this did not reach statistical significance. Conclusion The new Moses laser technology demonstrated good stone fragmentation capabilities when used in everyday clinical practice.

First clinical evaluation of a new single-use flexible ureteroscope (LithoVue™): a European prospective multicentric feasibility study

NARCIS (Netherlands)

Doizi, Steeve; Kamphuis, Guido; Giusti, Guido; Andreassen, Kim Hovgaard; Knoll, Thomas; Osther, Palle Jörn; Scoffone, Cesare; Pérez-Fentes, Daniel; Proietti, Silvia; Wiseman, Oliver; de la Rosette, Jean; Traxer, Olivier

2017-01-01

We evaluated a new digital single-use flexible ureteroscope, LithoVue™ with respect to deflection, image quality and maneuverability. A prospective cohort study was conducted in eight tertiary reference centers in Europe in December 2015 and January 2016. All consecutive patients included underwent

Laser lithotripsy for removal of uroliths in dogs

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Adams, Larry G.; Lulich, Jody P.

2006-02-01

Introduction: This study evaluated the ability to fragment and remove naturally occurring uroliths in dogs using a holmium: YAG laser. Methods: Twenty four dogs with naturally occurring uroliths including 10 spayed females and 14 neutered males. The dogs were 8.7 +/- 2.8 years old and weighed 13.7 +/- 8.0 kg. All dogs had bladder stones and 5 male dogs also had urethral stones. In female dogs, cystoscopy was performed using a rigid cystoscope with sheath diameter of 14 to 19 french. Cystoscopy was performed in males dogs using a 7.5 french diameter pediatric ureteroscope. Uroliths were fragmented using a 20 watt Holmium: YAG laser and the fragments were removed by basket extraction and voiding urohydropropulsion. Results: Average laser parameters for urolith fragmentation were 0.7 Joules at 8 Hertz (range: 0.5 to 1.3 Joules at 5 to 13 Hertz). All urolith fragments were successfully removed in all 10 female dogs and 11 of 14 male dogs. In one male dog, the urethra was too small to allow passage of the ureteroscope. In one of the male dogs, the urethral stones were successfully removed by laser lithotripsy, but removal of the bladder stones was performed by cystotomy. There was one complication of urethral perforation during attempts to pass an access sheath transurethrally in a dog with extensive proliferative urethritis. Conclusions: Laser lithotripsy is a safe and effective method of removing bladder and urethral stones in dogs provided the dog is large enough to permit transurethral passage of a cystoscope or ureteroscope.

TISU: Extracorporeal shockwave lithotripsy, as first treatment option, compared with direct progression to ureteroscopic treatment, for ureteric stones: study protocol for a randomised controlled trial.

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McClinton, Samuel; Cameron, Sarah; Starr, Kathryn; Thomas, Ruth; MacLennan, Graeme; McDonald, Alison; Lam, Thomas; N'Dow, James; Kilonzo, Mary; Pickard, Robert; Anson, Ken; Keeley, Frank; Burgess, Neil; Clark, Charles Terry; MacLennan, Sara; Norrie, John

2018-05-22

Urinary stone disease is very common with an estimated prevalence among the general population of 2-3%. Ureteric stones are associated with severe pain as they pass through the urinary tract and have significant impact on patients' quality of life due to the detrimental effect on their ability to work and need for hospitalisation. Most ureteric stones can be expected to pass spontaneously with supportive care. However, between one-fifth and one-third of cases require an intervention. The two standard active intervention options are extracorporeal shockwave lithotripsy (ESWL) and ureteroscopic stone retrieval. ESWL and ureteroscopy are effective in terms of stone clearance; however, they differ in terms of invasiveness, anaesthetic requirement, treatment setting, complications, patient-reported outcomes (e.g. pain after intervention, time off work) and cost. There is uncertainty around which is the most clinically effective in terms of stone clearance and the true cost to the NHS and to society (in terms of impact on patient-reported health and economic burden). The aim of this trial is to determine whether, in adults with ureteric stones, judged to require active intervention, ESWL is not inferior and is more cost-effective compared to ureteroscopic treatment as the initial management option. The TISU study is a pragmatic multicentre non-inferiority randomised controlled trial of ESWL as the first treatment option compared with direct progression to ureteroscopic treatment for ureteric stones. Patients aged over 16 years with a ureteric stone confirmed by non-contrast computed tomography of the kidney, ureter and bladder (CTKUB) will be randomised to either ESWL or ureteroscopy. The primary clinical outcome is resolution of the stone episode (no further intervention required to facilitate stone clearance) up to six months from randomisation. The primary economic outcome is the incremental cost per quality-adjusted life years (QALYs) gained at six months from

Multi-Institutional Validation of an OSATS for the Assessment of Cystoscopic and Ureteroscopic Skills.

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Argun, Omer Burak; Chrouser, Kristin; Chauhan, Sanket; Monga, Manoj; Knudsen, Bodo; Box, Geoffrey N; Lee, David I; Gettman, Matthew T; Poniatowski, Lauren H; Wang, Qi; Reihsen, Troy E; Sweet, Robert M

2015-10-01

We evaluated the internal and construct validity of an assessment tool for cystoscopic and ureteroscopic cognitive and psychomotor skills at a multi-institutional level. Subjects included a total of 30 urology residents at Ohio State University, Columbus, Ohio; Penn Presbyterian Medical Center, Philadelphia, Pennsylvania; and Mayo Clinic, Rochester, Minnesota. A single external blinded reviewer evaluated cognitive and psychomotor skills associated with cystoscopic and ureteroscopic surgery using high fidelity bench models. Exercises included navigation, basketing and relocation; holmium laser lithotripsy; and cystoscope assembly. Each resident received a total cognitive score, checklist score and global psychomotor skills score. Construct validity was assessed by calculating correlations between training year and performance scores (both cognitive and psychomotor). Internal validity was confirmed by calculating correlations between test components. The median total cognitive score was 91 (IQR 86.25, 97). For psychomotor performance residents had a median total checklist score of 7 (IQR 5, 8) and a median global psychomotor skills score of 21 (IQR 18, 24.5). Construct validity was supported by the positive and statistically significant correlations between training year and total cognitive score (r = 0.66, 95% CI 0.39-0.82, p = 0.01), checklist scores (r = 0.66, 95% CI 0.35-0.84, p = 0.32) and global psychomotor skills score (r = 0.76, 95% CI 0.55-0.88, p = 0.002). The internal validity of OSATS was supported since total cognitive and checklist scores correlated with the global psychomotor skills score. In this multi-institutional study we successfully demonstrated the construct and internal validity of an objective assessment of cystoscopic and ureteroscopic cognitive and technical skills, including laser lithotripsy. Copyright © 2015 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Comparative study on ureteroscopic lithotripsy and laparoscopic ureterolithotomy for treatment of unilateral upper ureteral stones Estudo comparativo entre litotripsia e ureterolitotomia laparoscópica no tratamento de cálculos unilaterais altos

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You-qiang Fang

2012-03-01

Full Text Available PURPOSE: To compare the curative effects of ureteroscopic lithotripsy and laparoscopic ureterolithotomy for unilateral upper ureteral stones, and to explore optimal surgical indications and skills. METHODS: Fifty cases of unilateral upper ureteral stones were randomly divided into two groups: one group underwent ureteroscopic holmium laser lithotripsy under epidural or lumbar anesthesia (n=25, and another group underwent laparoscopic ureterolithotomy under general anesthesia (n=25. Double-J stent was routinely indwelled in both groups. Operating time, postoperative hospitalization time, stone clearance rate and perioperative complications were compared. RESULTS: Operation was successfully performed in all 50 cases, and no open surgery was converted in any case. In the ureteroscopy and laparoscopy groups, the mean operating time was 49.0±10.7 min and 41.8±8.0 min (t=2.68, P=0.00999, respectively, their hospitalization time was 2.8±1.3 days vs. 2.9±0.8 days (t =-0.40, P=0.69413, and stone clearance rate was 88.0% (22/25 vs. 100% (25/25. Stone moved to the renal pelvis in three cases in the ureteroscopy group, and residual stones were removed by extracorporeal shock-wave lithotripsy (ESWL. All patients were followed up for more than three months, and no serious complications such as ureterostenosis occurred. CONCLUSIONS: Laparoscopic ureterolithotomy has a higher stone clearance rate and shorter operation time compared with ureteroscopic lithotripsy. Laparoscopic ureterolithotomy is one safe and effective treatment on unilateral upper ureteral stones.OBJETIVO: Comparar os efeitos curativos da litotripsia ureteroscópica e a ureterolitotomia laparoscópica para cálculos unilaterais altos e pesquisar as indicações e resultados. MÉTODOS: Cinquenta casos de cálculos unilaterais altos foram distribuídos aleatoriamente em dois grupos: um grupo submetido a litotripsia ureteroscópica com laser holmium sob anestesia epidural ou lombar (n=25 e

In vitro and in vivo comparison of optics and performance of a distal sensor ureteroscope versus a standard fiberoptic ureteroscope.

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Lusch, Achim; Abdelshehid, Corollos; Hidas, Guy; Osann, Kathryn E; Okhunov, Zhamshid; McDougall, Elspeth; Landman, Jaime

2013-07-01

Recent advances in distal sensor technologies have made distal sensor ureteroscopes both commercially and technically feasible. We evaluated performance characteristics and optics of a new generation distal sensor Flex-X(C) (X(C)) and a standard flexible fiberoptic ureteroscope Flex-X(2) (X(2)), both from Karl Storz, Tuttlingen, Germany. The ureteroscopes were compared for active deflection, irrigation flow, and optical characteristics. Each ureteroscope was evaluated with an empty working channel and with various accessories. Optical characteristics (resolution, grayscale imaging, and color representation) were measured using United States Air Force test targets. We digitally recorded a renal porcine ureteroscopy and laser ablation of a stone with the X(2) and with the X(C). Edited footage of the recorded procedure was shown to different expert surgeons (n=8) on a high-definition monitor for evaluation by questionnaire for image quality and performance. The X(C) had a higher resolution than the X(2) at 20 and 10 mm 3.17 lines/mm vs 1.41 lines/mm, 10.1 vs 3.56, respectively (P=0.003, P=0.002). Color representation was better in the X(C). There was no difference in contrast quality between the two ureteroscopes. For each individual ureteroscope, the upward deflection was greater than the downward deflection both with and without accessories. When compared with the X(2), the X(C) manifested superior deflection and flow (PX(C), and deflection as well as flow rate was less impaired by the various accessories.

Transurethral cystolithotripsy with a ureteroscope under local urethral anaesthesia and sedoanalgesia

International Nuclear Information System (INIS)

Uzun, H.; Tomak, Y.; Zorba, O.U.; Bostan, H.; Kalkan, M.

2013-01-01

Objective: To investigate if transurethral cystolithotripsy with a ureteroscope is feasible under local urethral anaesthesia, intravenous sedation and analgesia (sedoanalgesia). Methods: The prospective study was conducted from December 2009 to October 2010 and comprised 18 male patients with bladder calculi over 10mm in widest diameter regardless of etiology. The patients underwent transurethral holmium laser cystolithotripsy with a 9.5f semi-rigid ureteroscope. All patients received 2% idocaine gel local urethral anaesthesia, intravenous 0.03mg/kg midazolam and 7 micro g/kg alfentanil before the start of lithotripsy. Patients were discharged 1-3 hours after removal of the urethral foley catheter. Patients were asked to scale the discomfort and/or pain level by using visual analogue pain scale. Patients were followed up for at least 6 months. Results: The overall success rate was 89% (n=16). The mean stone diameter and total number of stones in the 16 patients was 21,48 +-6.7 (12-35) mm and 21 stones, respectively. The average age of the 16 patients was 52.3+-17.6 (45-78) years and mean operative time from begin ing of intravenous sedoanalgesia until urethral foley catheter insertion was 19.2+-18.9 (4-60) minutes. Mean pain score of the 16 patients after ureteroscopic cystolithotripsy was 1.75+-0.6cm (1-6 ). No anaesthesia-related serious complications occurred. After a follow-up of 18 months, recurrent stone formation and urethral stricture was not located in any patient. Conclusions: Transurethral cystolithotripsy with a ureteroscope under local urethral anaesthesia and sedoanalgesia for stones less than 30mm might offer patients safer anaesthesia and shorter operative time with favourable results. (author)

Durability of Flexible Ureteroscopes: A Prospective Evaluation of Longevity, the Factors that Affect it, and Damage Mechanisms.

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Legemate, Jaap D; Kamphuis, Guido M; Freund, Jan Erik; Baard, Joyce; Zanetti, Stefano P; Catellani, Michele; Oussoren, Harry W; de la Rosette, Jean J

2018-03-10

Flexible ureteroscopy is an established treatment modality for evaluating and treating abnormalities in the upper urinary tract. Reusable ureteroscope (USC) durability is a significant concern. To evaluate the durability of the latest generation of digital and fiber optic reusable flexible USCs and the factors affecting it. Six new flexible USCs from Olympus and Karl Storz were included. The primary endpoint for each USC was its first repair. Data on patient and treatment characteristics, accessory device use, ureteroscopy time, image quality, USC handling, disinfection cycles, type of damage, and deflection loss were collected prospectively. Ureteroscopy. USC durability was measured as the total number of uses and ureteroscopy time before repair. USC handling and image quality were scored. After every procedure, maximal ventral and dorsal USC deflection were documented on digital images. A total of 198 procedures were performed. The median number of procedures was 27 (IQR 16-48; 14h) for the six USCs overall, 27 (IQR 20-56; 14h) for the digital USCs, and 24 (range 10-37; 14h) for the fiber optic USCs. Image quality remained high throughout the study for all six USCs. USC handling and the range of deflection remained good under incremental use. Damage to the distal part of the shaft and shaft coating was the most frequent reason for repair, and was related to intraoperative manual forcing. A limitation of this study is its single-center design. The durability of the latest reusable flexible USCs in the current study was limited to 27 uses (14h). Damage to the flexible shaft was the most important limitation to the durability of the USCs evaluated. Prevention of intraoperative manual forcing of flexible USCs maximizes their overall durability. Current flexible ureteroscopes proved to be durable. Shaft vulnerability was the most important limiting factor affecting durability. Copyright © 2018 European Association of Urology. Published by Elsevier B.V. All rights

Thulium fiber laser lithotripsy using a muzzle brake fiber tip

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Hutchens, Thomas C.; Gonzalez, David A.; Irby, Pierce B.; Fried, Nathaniel M.

2017-02-01

The Thulium fiber laser (TFL) is being explored as an alternative to Holmium:YAG laser for lithotripsy. TFL beam profile allows coupling of higher power into smaller fibers than multimode Holmium laser beam, without proximal fiber tip degradation. A smaller fiber provides more space in ureteroscope working channel for increased saline irrigation and allows maximum ureteroscope flexion. However, distal fiber tip burnback increases as fiber diameter decreases. Previous studies utilizing hollow steel sheaths around recessed distal fiber tips reduced fiber burnback, but increased retropulsion. In this study, a "fiber muzzle brake" was tested for reducing fiber burnback and stone retropulsion. TFL lithotripsy studies were performed at 1908 nm, 35 mJ, 500 μs, and 300 Hz using a 100-μm-core fiber. The optimal stainless steel muzzle brake tip tested consisted of a 1-cm-long, 560-μm-OD, 360-μm-ID tube with 275-μm thru hole located 250-μm from the distal end. The fiber tip was recessed a distance of 500 μm. Stone phantom retropulsion, fiber tip burnback, and calcium oxalate stone ablation studies were performed, ex vivo. Small stones with a mass of 40 +/- 4 mg and 4-mm-diameter were ablated over a 1.5-mm sieve in 25 +/- 4 s (n=10), without distal fiber tip burnback. Reduction in stone phantom retropulsion distance by 50% and 85% was observed when using muzzle brake tips versus 100-μm-core bare fibers and hollow steel tip fibers. The muzzle brake fiber tip provided efficient stone ablation, reduced stone retropulsion, and minimal fiber degradation during TFL lithotripsy.

Retrograde intrarenal stone surgery for extracorporeal shock-wave lithotripsy-resistant kidney stones

DEFF Research Database (Denmark)

Jung, Helene; Nørby, Bettina; Osther, Palle Jörn

2006-01-01

OBJECTIVE: The newer flexible ureteroscopes, 150-200-microm holmium YAG laser fibres and superflexible Dormia baskets have made it possible to reach and treat stones in all parts of the kidney. The object of this evaluation was to study the outcome of retrograde intrarenal stone surgery (RIRS......) for extracorporeal shock-wave lithotripsy (ESWL)-resistant kidney stones. MATERIAL AND METHODS: A total of 38 consecutive patients (18 males, 20 females) participated in the study. All patients had undergone ESWL prior to RIRS without success. In all cases the stones could be reached with the endoscope. Calculi...... ranged in size from 3 to 20 mm (mean 9 mm). In 32 cases the stones were fragmented using a holmium YAG laser and in six the stones could be extracted using zero-tip Dormia baskets without fragmentation. Sixteen patients had lower calyceal calculi and eight had an abnormal anatomy of the upper urinary...

Utility of Flexible Ureterorenoscopy and Laser Lithotripsy in the Treatment of Multiple Intrarenal Stones

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Hasan Yılmaz

2017-09-01

Full Text Available Objective: We aimed to determine the safety and efficacy of flexible ureterorenoscopy and Holmium laser lithotripsy in treating multiple intrarenal stones. Materials and Methods: We identified 32 consecutive patients with multiple intrarenal stones who underwent flexible ureterorenoscopy and/or laser lithotripsy performed by a single surgeon. Informed consent was obtained from all participants before treatment. Each patient was evaluated in terms of stone location, stone number, stone size, stone burden (cumulative stone length, body mass index, operative time, stone-free rate, and perioperative complications. Results: The median age of the patients was 38 years [interquartile range (IQR, 34.25-52.00]. The patients had a total of 75 intrarenal calculi. The average number of stones per patient was 2.50 (IQR, 2.0-3.0. The median total stone burden per patient was 23.0 mm (IQR, 19.0-28.0 mm. Twenty-one patients (65.5% had stone burdens >20 mm, and 11 (34.5% had burdens ≤20 mm. The overall final stone-free rate was 78.1%. The stone-free rates for patients with stone burdens ≤20 mm and >20 mm were 81.8% (9/11 and 76.2% (16/21, respectively (p=0.544. A perioperative complication (urinary leakage occurred in one patient. Postoperative complications were recorded in four (12.5% patients; a urinary tract infection in one, pain requiring parenteral medication in two, and hematuria in one. Conclusion: Flexible ureterorenoscopy combined with laser lithotripsy may be an effective treatment option for patients with multiple intrarenal stones; we noted only a few minor complications. The success rate was higher in patients with stone burdens ≤20 mm.

Technical issues of electric nanopulse contact lithotripsy as factors affecting lithotripsy effectiveness and probe resourses

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L. Yu. Ivanova

2012-01-01

Full Text Available To assess the relationship of main technical issues of electric nanopulse contact lithotripsy (CLT with lithotripsy effectiveness and lithotripsy resources of probe.Electric nanopulses were transmitted by the flexible probes and the lithotripter «Urolit». The relationship between lithotripsy effectiveness and tip diameter of probes, pulse energy, pulse frequency was assessed, and resources of lithotripsy probes with different diameters of the tip were analyzed.Sufficient number of electric nanopulse to destroy stone models was less when tip diameter, nanopulse energy and frequency were greater.Effectiveness of electric nanopulse CLT can be enhanced with the increase of nanopulse energy, frequency and probe diameter. Complex correction of technical issues of electric nanopulse CLT can be a way of probe resources saving.

Holmium laser lithotripsy (HoLL) of ureteral calculi

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Kuntz, Rainer M.; Lehrich, Karin; Fayad, Amr

2001-05-01

The effectiveness and side effects of ureteroscopic HoLL of ureteral stones should be evaluated. In 63 patients (17 female, 46 males) a total of 75 stones of 3-20 mm diameter were treated with ureteroscopic HoLL. 18.7 percent of stones were located in the proximal third, 24.0 percent in the middle third and 57.3 percent in the distal third of the ureter. HoLL was performed with small diameter semirigid and flexible ureteroscopes, 220 or 365 nm flexible laser fibers and a holmium:YAG laser at a power of 5-15 W (0.5-1.0 J, 10- 15 Hz). 47 of 63 patients (74.6 percent) were immediately free of stones, and 8 others (12.6 percent) lost their residual fragments spontaneously within two weeks. Another 2 patients received additional chmolitholysis for uric acid stone fragments, i.e. 90.5 percent of patients were stone free by one sitting of ureterscopic HoLL. Of the remaining 6 patients (9.5 percent) who still had residual calculi 4 weeks after HoLL, 2 asymptomatic patients refused any additional treatment, 2 patients preferred treatment with ESWL, and 2 patients had a successful second HoLL, thereby raising the success rate of ureteroscopic HoLL to 93.7 percent. 2 patients showed contrast medium extravasation on retrograde ureterograms, due to guide wire perforation. No ureteral stricture occurred. In conclusion, transurethral ureteroscopic HoLL proved to be a safe and successful minimal invasive treatment of ureteral calculi.

Renal arteriovenous fistula: A rare complication of electro-hydraulic ...

African Journals Online (AJOL)

A 62-year-old man with type 1 Von Willebrand's disease was electively admitted to a Northern Ireland district general hospital for endoscopic management of a 1 cm right lower pole calculus. After pre-operative administration of appropriate haematological factors, flexible ureteroscopic electro-hydraulic lithotripsy (EHL).

Application of ureterorenoscope and flexible ureterorenoscope lithotripsy in removing calculus from extracorporeal living donor renal graft: a single-center experience.

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Lin, Chun-Hua; Zhang, Zuo-Fu; Wang, Jiahui; Yu, Lu-Xin; Wang, Wen-Ting; Shi, Lei; Lin, Xiang-Nan

2017-11-01

Here, we reported our clinical application of ureterorenoscope (URS) and flexible URS lithotripsy in stone removal on 10 cases of excised living donor kidney graft. After the extraction of donor kidney by retroperitoneal laparoscopy, the donor graft was perfused with 4 °C HCA solution. Calculus between 2-4 mm were removed intact with lithotomy forceps under direct vision of URS. Larger calculi of >4 mm were fractured with flexible URS combining holmium laser lithotripsy. Fragments of the calculus were extracted with basket extractor and lithotomy forceps. All operations were successful. The operation time was 14-31 min (average 21.2 ± 6.3 min). The kidneys were then transplanted to the recipients using routine procedure. The transplanted kidneys functioned well after transplantation. Gross hematuria resolved 1-4 d after operation (average 2.6 ± 0.9 d). The transplanted kidneys functioned well without early complications such as functional recovery delay and acute graft rejection. The donors and recipients were followed for 12 months. The size of the transplanted kidneys was normal and new stones or urinary obstruction was not seen upon urinary color Doppler ultrasound examination. In conclusion, we believe it is feasible, safe and effective to use URS or flexible URS combining holmium laser lithotripsy on extracorporeal living donor kidney.

Fiber optic muzzle brake tip for reducing fiber burnback and stone retropulsion during thulium fiber laser lithotripsy

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Hutchens, Thomas C.; Gonzalez, David A.; Irby, Pierce B.; Fried, Nathaniel M.

2017-01-01

The experimental thulium fiber laser (TFL) is being explored as an alternative to the current clinical gold standard Holmium:YAG laser for lithotripsy. The near single-mode TFL beam allows coupling of higher power into smaller optical fibers than the multimode Holmium laser beam profile, without proximal fiber tip degradation. A smaller fiber is desirable because it provides more space in the ureteroscope working channel for increased saline irrigation rates and allows maximum ureteroscope deflection. However, distal fiber tip burnback increases as fiber diameter decreases. Previous studies utilizing hollow steel sheaths around recessed distal fiber tips reduced fiber burnback but increased stone retropulsion. A "fiber muzzle brake" was tested for reducing both fiber burnback and stone retropulsion by manipulating vapor bubble expansion. TFL lithotripsy studies were performed at 1908 nm, 35 mJ, 500 μs, and 300 Hz using a 100-μm-core fiber. The optimal stainless steel muzzle brake tip tested consisted of a 1-cm-long, 560-μm-outer-diameter, 360-μm-inner-diameter tube with a 275-μm-diameter through hole located 250 μm from the distal end. The fiber tip was recessed a distance of 500 μm. Stone phantom retropulsion, fiber tip burnback, and calcium oxalate stone ablation studies were performed ex vivo. Small stones with a mass of 40±4 mg and 4-mm-diameter were ablated over a 1.5-mm sieve in 25±4 s (n=10) without visible distal fiber tip burnback. Reduction in stone phantom retropulsion distance by 50% and 85% was observed when using muzzle brake tips versus 100-μm-core bare fibers and hollow steel tip fibers, respectively. The muzzle brake fiber tip simultaneously provided efficient stone ablation, reduced stone retropulsion, and minimal fiber degradation during TFL lithotripsy.

Extracorporeal shock wave lithotripsy (ESWL) vs. ureterorenoscopic (URS) manipulation in proximal ureteric stone.

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Manzoor, Salman; Hashmi, Altaf Hussain; Sohail, Muhammad Ali; Mahar, Feroz; Bhatti, Shahid; Khuhro, Abdul Qayoom

2013-10-01

To compare the stone free rate at one week after extracorporeal shock wave lithotripsy (ESWL) and ureterorenoscopic (URS) manipulation for proximal ureteric stone (10 - 15 mm size). Randomized controlled trial. Sindh Institute of Urology and Transplantation (SIUT), Karachi, from August 2010 to February 2011. One hundred and ninety patients with 10 - 15 mm proximal urteric stone, in each group were treated with ESWL and ureterorenoscopic manipulation by using an 8.0 or 8.5 Fr semi rigid ureteroscope. Intracorporeal lithotripsy was performed by using pneumatic lithoclast. The stone free rate were compared between groups by considering size of stone at one week after procedure. The success rate, retreatment rate, auxiliary procedure and complication rate were compared in each group. Success rate was 49.2% for ESWL and 57.8% for URS (p = 0.008). The re-treatment rate was significantly higher in ESWL group than in URS group (40% vs. 11 and 18% in URS group). Although ESWL is regarded as the preferred choice of treatment for proximal ureteric stone, the present results suggest that ureterorenoscopic manipulation with intracorporeal lithotripsy is a safe alternative, with an advantage of obtaining an earlier or immediate stone-free status. Laparoscopic approaches are reasonable alternatives in cases, where ESWL and URS have failed.

Efficacy Management of Urolithiasis: Flexible Ureteroscopy versus Extracorporeal Shockwave Lithotripsy.

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Tauber, Volkmar; Wohlmuth, Martin; Hochmuth, Andreas; Schimetta, Wolfgang; Schimetta, Wofgang; Krause, F Steffen

2015-01-01

To evaluate the efficacy of flexible ureterscopy (fURS) and extracorporal shockwave lithotripsy (SWL) in the treatment of urolithiasis, complemented by a subgroup analysis of lower pole calyx. Retrospective analysis of patients treated by fURS or SWL was performed by independent variables such as gender, age, nephrolith size, double-J stent (DJ stent) and stone localisation. Out of 326 patients, 165 were treated by SWL and 161 by fURS. Complete stone removal was achieved by fURS in 83.2% and by SWL in 43.0% (p auxillary DJ stent was performed more often preoperative before fURS. The subgroup analysis of lower pole calyx confirmed these evaluations. Complete stone-free removal was almost 8 times higher after fURS compared to SWL. The efficacy of fURS in treatment of urolithiasis is substantially higher than the efficacy of SWL. © 2015 S. Karger AG, Basel.

Extracorporeal Shock Wave Lithotripsy (ESWL) vs. Ureterorenoscopic (URS) Manipulation in Proximal Ureteric Stone

International Nuclear Information System (INIS)

Manzoor, S.; Khuhro, A.Q.; Hashmi, A.H.; Sohail, M.A.; Mahar, F.; Bhatti, S.

2013-01-01

Objective: To compare the stone free rate at one week after extracorporeal shock wave lithotripsy (ESWL) and ureterorenoscopic (URS) manipulation for proximal ureteric stone (10 - 15 mm size). Study Design: Randomized controlled trial. Place and Duration of Study: Sindh Institute of Urology and Transplantation (SIUT), Karachi, from August 2010 to February 2011. Methodology: One hundred and ninety patients with 10 - 15 mm proximal urteric stone, in each group were treated with ESWL and ureterorenoscopic manipulation by using an 8.0 or 8.5 Fr semi rigid ureteroscope. Intracorporeal lithotripsy was performed by using pneumatic lithoclast. The stone free rate were compared between groups by considering size of stone at one week after procedure. The success rate, retreatment rate, auxiliary procedure and complication rate were compared in each group. Results: Success rate was 49.2% for ESWL and 57.8% for URS (p = 0.008). The re-treatment rate was significantly higher in ESWL group than in URS group (40% vs. 11 and 18% in URS group). Conclusion: Although ESWL is regarded as the preferred choice of treatment for proximal ureteric stone, the present results suggest that ureterorenoscopic manipulation with intracorporeal lithotripsy is a safe alternative, with an advantage of obtaining an earlier or immediate stone-free status. Laparoscopic approaches are reasonable alternatives in cases, where ESWL and URS have failed. (author)

Outcome analysis of holmium laser and pneumatic lithotripsy in the endoscopic management of lower ureteric calculus in pediatric patients: a prospective study

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Ankur Jhanwar

Full Text Available ABSTRACT Objective: To analyse outcomes of holmium laser and pneumatic lithotripsy in treatment of lower ureteric calculus in pediatric patients. Materials and methods: Prospective study conducted between August 2013 and July 2015. Inclusion criteria were lower ureteric calculus with stone size ≤1.5cms. Exclusion criteria were other than lower ureteric calculus, stone size ≥1.5cms, congenital renal anomalies, previous ureteral stone surgery. Patients were divided into two groups. Group A underwent pneumatic and group B underwent laser lithotripsy procedure. Patient's baseline demographic and peri-operative data were recorded and analysed. Post operatively X-ray/ultrasound KUB (Kidney, ureter and bladder was performed to assess stone free status. Results: A total of 76 patients who met the inclusion criteria to ureteroscopic intracorporeal lithotripsy were included. Group A and B included 38 patients in each. Mean age was 12.5±2.49 in Group A and 11.97±2.74 years in Group B respectively (p=0.38. Overall success rate was 94.73% in Group A and 100% in Group B, respectively (p=0.87. Conclusion: Holmium Laser lithotripsy is as efficacious as pneumatic lithotripsy and can be used safely for the endoscopic management of lower ureteric calculus in pediatric patients. However, holmium laser requires more expertise and it is a costly alternative.

Thermal Response to High-Power Holmium Laser Lithotripsy.

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Aldoukhi, Ali H; Ghani, Khurshid R; Hall, Timothy L; Roberts, William W

2017-12-01

The aim of this study was to investigate "caliceal" fluid temperature changes during holmium laser activation/lithotripsy using settings up to 40 W power output with different irrigation flow rates. The experimental system consisted of a glass test tube (diameter 10 mm/length 75 mm) filled with deionized water, to mimic a calix. Real-time temperature was recorded using a thermocouple (Physitemp, NJ) positioned 5 mm from the bottom of the tube. A 200 μm laser fiber (Flexiva; Boston Scientific, MA) was introduced through the working channel of a disposable ureteroscope (LithoVue; Boston Scientific) and the laser fiber tip was positioned 15 mm above the bottom of the test tube. Deionized water irrigation (room temperature) through the working channel of the ureteroscope was delivered at flow rates of 0, 7-8, 14-15, and 38-40 mL/minute. A 120-W holmium laser (pulse 120; Lumenis, CA) was used. The following settings were explored: 0.5 J × 10 Hz, 1.0 J × 10 Hz, 0.5 J × 20 Hz, 1.0 J × 20 Hz, 0.5 J × 40 Hz, 1.0 J × 40 Hz, and 0.5 J × 80 Hz. During each experiment, the laser was activated continuously for 60 seconds. Temperature increased with increasing laser power output and decreasing irrigation flow rate. The highest temperature, 70.3°C (standard deviation 2.7), occurred with laser setting of 1.0 J × 40 Hz and no irrigation after 60 seconds of continuous laser firing. None of the tested laser settings and irrigation parameters produced temperature exceeding 51°C when activated for only 10 seconds of continuous laser firing. High-power holmium settings fired in long bursts with low irrigation flow rates can generate high fluid temperatures in a laboratory "caliceal" model. Awareness of this risk allows urologist to implement a variety of techniques (higher irrigation flow rates, intermittent laser activation, and potentially cooled irrigation fluid) to control and mitigate thermal

Incidence and Predictors for Ipsilateral Hydronephrosis Following Ureteroscopic Lithotripsy.

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Barbour, Meredith L; Raman, Jay D

2015-09-01

To review our experience in using ureteroscopy (URS) with lithotripsy for renal or ureteral calculi to determine the incidence and predictors of postprocedural ipsilateral hydronephrosis. Records of 324 URS cases for renal or ureteral calculi with imaging performed 4-12 weeks postprocedure were reviewed. Ipsilateral hydronephrosis was determined by computed tomography scan or renal ultrasound. Univariate and multivariate analyses determined the factors associated with hydronephrosis. 176 men and 148 women with a median age of 50 years were included. Median stone size was 6 mm and operative duration was 60 minutes; 30% of patients had multiple calculi; and 35% had undergone a prior ipsilateral URS. Overall, 49 of 324 patients (15%) had evidence of hydronephrosis, with 65% of these patients having symptoms and 40% requiring ancillary procedures. On multivariate analysis, increasing stone diameter (odds ratio [OR] 8.9, 95% confidence interval [CI] 1.9-23.8, P = .03), prior ipsilateral URS (OR 7.7, 95% CI 1.8-28.2, P = .006), longer operative duration (OR 6.5, 95% CI 1.8-16.3, P = .02), and renal colic symptoms (OR 48.3, 95% CI 14.7-71.4, P hydronephrosis. Conversely, other factors including stone impaction at procedure, ureteral dilation, use of an access sheath, intraoperative perforation, or use of a stent did not associate with ipsilateral hydronephrosis. In this contemporary cohort study, 15% of patients undergoing URS had evidence of ipsilateral hydronephrosis. Larger stone size, longer OR duration, prior ipsilateral URS, and recurrent colic were associated with an increased likelihood for this observation. Patients and stone cases with such characteristics likely warrant imaging modalities beyond plain radiography. Copyright © 2015 Elsevier Inc. All rights reserved.

Determinants of holmium:yttrium-aluminum-garnet laser time and energy during ureteroscopic laser lithotripsy.

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Molina, Wilson R; Marchini, Giovanni S; Pompeo, Alexandre; Sehrt, David; Kim, Fernando J; Monga, Manoj

2014-04-01

To evaluate the association of preoperative noncontrast computed tomography stone characteristics, laser settings, and stone composition with cumulative holmium:yttrium-aluminum-garnet (Ho:YAG) laser time/energy. We retrospectively reviewed patients who underwent semirigid/flexible ureteroscopy and Ho:YAG laser lithotripsy (200 or 365 μm laser fiber; 0.8-1.0 J energy; and 8-10 Hz rate) at 2 tertiary care centers (April 2010-May 2012). Studied parameters were as follows: patient's characteristics; stone characteristics (location, burden, hardness, and composition); total laser time and energy; and surgical outcomes. One hundred patients met our inclusion criteria. Mean stone size was 1.01 ± 0.42 cm and volume 0.33 ± 0.04 cm(3). Mean stone radiodensity was 990 ± 296 HU, and Hounsfield units density 13.8 ± 6.0 HU/mm. All patients were considered stone free. Stone size and volume had a significant positive correlation with laser energy (R = 0.516, P R = 0.621, P R = 0.477, P R = 0.567, P stone size, only the correlation between HU and laser time was significant (R = 0.262, P = .011). In the multivariate analysis, with exception of stone composition (P = .103), all parameters significantly increased laser energy (R(2) = 0.524). Multivariate analysis revealed a positive significant association of laser time with stone volume (P R(2) = 0.512). In multivariate analysis for laser energy, only calcium phosphate stones required less energy to fragment compared with uric acid stones. No significant differences were found in the multivariate laser time model. Ho:YAG laser cumulative energy and total time are significantly affected by stone dimensions, hardness location, fiber size, and power. Kidney location, laser fiber size, and laser power have more influence on the final laser energy than on the total laser time. Calcium phosphate stones require less laser energy to fragment. Copyright © 2014 Elsevier Inc. All rights reserved.

Use of the Escape nitinol stone retrieval basket facilitates fragmentation and extraction of ureteral and renal calculi: a pilot study.

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Kesler, Stuart S; Pierre, Sean A; Brison, Daniel I; Preminger, Glenn M; Munver, Ravi

2008-06-01

Advances in ureteroscope and stone basket design have catapulted ureteroscopy to the forefront of surgical stone management; however, persistent problems such as stone migration continue to challenge urologists. The Escape nitinol stone retrieval basket (Boston Scientific, Natick, MA) is a stone basket designed to capture calculi and facilitate simultaneous laser lithotripsy in situ. We report our initial experience with the Escape basket for the management of urinary calculi and compare the use of this device with other methods of optimizing ureteroscopic stone management. A prospective evaluation of 23 patients undergoing ureteroscopic holmium:yttrium-aluminum-garnet laser lithotripsy of urinary calculi was performed at two institutions by two surgeons (R.M. and G.M.P). The Escape basket was used to prevent retrograde ureteral stone migration or to facilitate fragmentation and extraction of large renal calculi. Patient demographics and perioperative parameters were assessed. Twenty-three patients (16 men, 7 women), with a mean age of 55.5 years (range 33-74 yrs) were treated for renal (n = 9) or ureteral (n = 14) calculi. The mean stone diameter was 1.4 cm (range 0.4-2.5 cm), mean fragmentation time was 44.1 minutes (range 10-75 min), and mean energy used was 3.1 kJ (range 0.4-10.6 kJ). No complications were encountered. Eighty-seven percent (20/23) of patients were rendered completely stone free after ureteroscopic laser lithotripsy using the Escape basket. Of the three patients with residual calculi, one patient with a 2.5-cm renal calculus had residual fragments larger than 3 mm, and two patients with large renal calculi had residual fragments smaller than 3 mm. The Escape basket appears to be safe and effective in preventing stone migration and facilitating ureteroscopic laser lithotripsy and stone extraction.

Ureteroscopy and stone lithotripsy with lithoclast: personal experience.

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Leidi, G L; Berti, G L; Canclini, L; Giola, V; Maccaroni, A; Raimoldi, A; Veneroni, L; Bacchioni, A M

1997-06-01

Ureteroscopy has become a common technique in the diagnosis and treatment of ureteral pathologies, but this procedure is quite invasive and some complications have been reported in literature. In our Institute 49 patients underwent ureteroscopy and ballistic lithotripsy with lithoclast for ureteral stones. The stones were localized both in the middle and distal part of the ureter. We used a small caliber 7-8.5 Wolf ureteroscope. The treatments were performed under antibiotic prophylaxis. Direct access to the ureter without dilation of the meatus was obtained in 97.96% of patients. The stones were easily reached in 93.88% of the cases and satisfactory fragmentation was obtained in 90.7%. In 4 patients (9.3%) one or more large stone fragments escaped into the kidney, requiring the patients to be treated with ESWL. No major complications occurred: no ureteral perforations, no important bleeding and no severe or persistent infections. All patients were discharged in one to four days postoperatively. The authors conclude that ureteroscopy using small caliber instruments with Lithoclast is a safe and satisfactory alternative to ESWL in the treatment of ureteral stones.

Single use disposable digital flexible ureteroscopes: an ex-vivo assessment and cost analysis.

Science.gov (United States)

Hennessey, D B; Fojecki, G; Papa, N; Lawrentschuk, N; Bolton, D

2018-04-15

The single use flexible ureteroscope (fURS), the LithoVue is an important recent development. We aim to measure the capability of this instrument and to assess if there is a benefit to switching to single use instruments. The LithoVue was compared to Olympus URF-V and Stortz Flex Xc ex-vivo. An analysis of reusable fURS usage was performed to evaluate damage, durability and maintenance costs. This was then compared to the projected costs of using single use instruments. Flexion, deflection and irrigation flow of the LithoVue was equivalent, if not better than reusable instruments. An analysis of 234 procedures with 7 new Olympus URF-V scopes, revealed 15 scope damages. Staghorn stones and lower pole/midzone stones were significant risk factors for damage, p=0.014. Once damage occurred, it was likely to occur again. Total repair costs were $162,628 (£92,411), the mean cost per case is $695 (£395). Factoring in the purchase cost, cleaning and repair costs, and the cumulative cost of 28 reusable fURS cases is approximately $50,000 (£28,412). If the LithoVue was priced at $1200 AUD, switching to a single use scope would cost approximately $35,000 (£19,888). The LithoVue is analogous to reusable fURS scopes in regard to standard technical metrics. Depending on its purchase cost it may also represent a cost saving for hospitals when compared to the cumulative costs of maintaining reusable fURS. Additionally, urologist may consider to use the scope in cases in which reusable scope damage is anticipated. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Percutaneous Transhepatic Endoscopic Holmium Laser Lithotripsy for Intrahepatic and Choledochal Biliary Stones

International Nuclear Information System (INIS)

Rimon, Uri; Kleinmann, Nir; Bensaid, Paul; Golan, Gil; Garniek, Alexander; Khaitovich, Boris; Winkler, Harry

2011-01-01

Purpose: To report our approach for treating complicated biliary calculi by percutaneous transhepatic endoscopic biliary holmium laser lithotripsy (PTBL). Patients and Methods: Twenty-two symptomatic patients (11 men and 11 women, age range 51 to 88 years) with intrahepatic or common bile duct calculi underwent PTBL. Nine patients had undergone previous gastrectomy and small-bowel anastomosis, thus precluding endoscopic retrograde cholangiopancreatography. In the other 13 patients, stone removal attempts by ERCP failed due to failed access or very large calculi. We used a 7.5F flexible ureteroscope and a 200-μm holmium laser fiber by way of a percutaneous transhepatic tract, with graded fluoroscopy, to fragment the calculi with direct vision. Balloon dilatation was added when a stricture was seen. The procedure was performed with the patient under general anaesthesia. A biliary drainage tube was left at the end of the procedure. Results: All stones were completely fragmented and flushed into the small bowel under direct vision except for one patient in whom the procedure was aborted. In 18 patients, 1 session sufficed, and in 3 patients, 2 sessions were needed. In 7 patients, balloon dilatation was performed for benign stricture after Whipple operation (n = 3), for choledochalenteric anastomosis (n = 3), and for recurrent cholangitis (n = 1). Adjunctive “balloon push” (n = 4) and “rendezvous” (n = 1) procedures were needed to completely clean the biliary tree. None of these patients needed surgery. Conclusion: Complicated or large biliary calculi can be treated successfully using PTBL. We suggest that this approach should become the first choice of treatment before laparoscopic or open surgery is considered.

The Post-Ureteroscopic Lesion Scale (PULS)

DEFF Research Database (Denmark)

Schoenthaler, Martin; Buchholz, Noor; Farin, Erik

2014-01-01

The Post-Ureteroscopic Lesion Scale (PULS) offers a simple grading system for the description of ureteral lesions after ureteroscopy. In this article, we present the results of a video-based multicenter evaluation of the inter-rater reliability of clinically important PULS grades 0-3....

Comparison of a 4.5 F semi-rigid ureteroscope with a 7.5 F rigid ureteroscope in the treatment of ureteral stones in preschool-age children.

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Atar, Murat; Sancaktutar, Ahmet Ali; Penbegul, Necmettin; Soylemez, Haluk; Bodakci, Mehmet Nuri; Hatipoglu, Namik Kemal; Bozkurt, Yasar; Cakmakci, Suleyman

2012-12-01

The aim of this study was to compare the success and complication rates of a 4.5 F ureteroscope with a 7.5 F ureteroscope in the treatment of urolithiasis in preschool-age children. We retrospectively reviewed 69 ureteroscopy (URS) procedures in a pediatric population (40 boys, 29 girls). We divided the patients into two groups according to the type of ureteroscope used: group 1 (n = 42, Storz 7.5 F) and group 2 (n = 27, Wolf 4.5 F). We statistically compared all the procedures performed in both groups regarding patient age, complication rates, whether the procedure was therapeutic, and whether we used a guidewire. Additionally, in cases with ureteral stones, we also compared the stone clearance rate and the necessity of X-ray imaging between the two groups. The mean patient age was 56.04 months in group 1 and 47.48 months in group 2 (p = 0.057). The stone-free rate was 78.6 % in group 1 and 92.6 % in group 2 (p > 0.05). However, when we compared the stone-free rates for patients younger than 3 years, the rate was 66.7 % in group 1 and 93.8 % in group 2 (p < 0.05). The difference was not statistically significant for patients between the ages of 4 and 7 years. The success and failure rates revealed better outcomes for treatment of ureteral stones with a 4.5 F ureteroscope. We recommend the use of the mini-ureteroscope, especially in infants and preschool-age children.

An integrated fiber and stone basket device for use in Thulium fiber laser lithotripsy

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Wilson, Christopher R.; Hutchens, Thomas C.; Hardy, Luke A.; Irby, Pierce B.; Fried, Nathaniel M.

2014-03-01

The Thulium fiber laser (TFL) is being explored as an alternative laser lithotripter to the Holmium:YAG laser. The TFL's superior near-single mode beam profile enables higher power transmission through smaller fibers with reduced proximal fiber tip damage. Recent studies have also reported that attaching hollow steel tubing to the distal fiber tip decreases fiber degradation and burn-back without compromising stone ablation rates. However, significant stone retropulsion was observed, which increased with pulse rate. In this study, the hollow steel tip fiber design was integrated with a stone basket to minimize stone retropulsion during ablation. A device was constructed consisting of a 100-μm-core, 140-μm-OD silica fiber outfitted with 5-mm-long stainless steel tubing at the distal tip, and integrated with a 1.3-Fr (0.433-mm-OD) disposable nitinol wire basket, to form an overall 1.9-Fr (0.633-mm- OD) integrated device. This compact design may provide several potential advantages including increased flexibility, higher saline irrigation rates through the ureteroscope working channel, and reduced fiber tip degradation compared to separate fiber and stone basket manipulation. TFL pulse energy of 31.5 mJ with 500 μs pulse duration and pulse rate of 500 Hz was delivered through the integrated fiber/basket device in contact with human uric acid stones, ex vivo. TFL stone ablation rates measured 1.5 +/- 0.2 mg/s, comparable to 1.7 +/- 0.3 mg/s (P > 0.05) using standard bare fiber tips separately with a stone basket. With further development, this device may be useful for minimizing stone retropulsion, thus enabling more efficient TFL lithotripsy at higher pulse rates.

Impact of Hydronephrosis on Treatment Outcome of Solitary Proximal Ureteral Stone After Extracorporeal Shock Wave Lithotripsy

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Hsi-Lin Hsiao

2008-10-01

Full Text Available The purpose of this study was to investigate the impact of hydronephrosis on the treatment outcome of patients with a solitary proximal ureteral stone after extracorporeal shock wave lithotripsy (ESWL. A total of 182 consecutive patients who underwent ESWL for a solitary proximal ureteral stone of between 5 and 20 mm in size in our institution were included in this study. The degree of hydronephrosis was defined by renal ultrasonography. Patient data, stone size, shock wave numbers and shock wave energy were also recorded. Treatment outcome was evaluated 3 months after the first session of ESWL. In multivariate analysis, only the maximal stone length (odds ratio [OR], 0.15; 95% confidence interval [CI], 0.03–0.91; p = 0.04 and the degree of hydronephrosis (OR, 0.40; 95% CI, 0.16–0.98; p = 0.045 were significant predicting factors for stone-free status 3 months after ESWL. For stones ≤ 10 mm, the stone-free rate decreased from 80% in patients with mild hydronephrosis to 56.4% in those with moderate to severe hydro-nephrosis. For stones > 10 mm, the stone-free rate decreased further, from 65.2% in patients with mild hydronephrosis to 33.3% in those with moderate to severe hydronephrosis. In summary, patients with a solitary proximal ureteral stone and a stone > 10 mm, the treatment outcome after ESWL was not good if moderate to severe hydronephrosis was noted on ultrasonography. Alternative treatments, such as ureteroscopic lithotripsy, may be appropriate as initial treatment or after failure of one session of ESWL.

Current state of clinical lithotripsy

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Lingeman, James E.

2003-10-01

Extracorporeal shock wave lithotripsy (ESWL) has revolutionized the treatment of urolithiasis. Because of the clinical success of the original lithotriptor, the Dornier HM3, numerous manufacturers introduced different approaches to lithotripsy based on empiricism rather than an understanding of the fundamental mechanisms of this new technology. Our understanding of shock wave physics and the physiologic effects of shock waves has progressed greatly over the last decade resulting in insights that hopefully will be reflected favorably in future lithotriptor designs and lithotripsy techniques.

Proteus mirabilis viability after lithotripsy of struvite calculi

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Prabakharan, Sabitha; Teichman, Joel M. H.; Spore, Scott S.; Sabanegh, Edmund; Glickman, Randolph D.; McLean, Robert J. C.

2000-05-01

Urinary calculi composed of struvite harbor urease-producing bacteria within the stone. The photothermal mechanism of holmium:YAG lithotripsy is uniquely different than other lithotripsy devices. We postulated that bacterial viability of struvite calculi would be less for calculi fragmented with holmium:YAG irradiation compared to other lithotripsy devices. Human calculi of known struvite composition (greater than 90% magnesium ammonium phosphate hexahydrate) were incubated with Proteus mirabilis. Calculi were fragmented with no lithotripsy (controls), or shock wave, intracorporeal ultrasonic, electrohydraulic, pneumatic, holmium:YAG or pulsed dye laser lithotripsy. After lithotripsy, stone fragments were sonicated and specimens were serially plated for 48 hours at 38 C. Bacterial counts and the rate of bacterial sterilization were compared. Median bacterial counts (colony forming units per ml) were 8 X 106 in controls and 3 X 106 in shock wave, 3 X 107 in ultrasonic, 4 X 105 in electrohydraulic, 8 X 106 in pneumatic, 5 X 104 in holmium:YAG and 1 X 106 in pulsed dye laser lithotripsy, p less than 0.001. The rate of bacterial sterilization was 50% for holmium:YAG lithotripsy treated stones versus 0% for each of the other cohorts, p less than 0.01. P. mirabilis viability is less after holmium:YAG irradiation compared to other lithotripsy devices.

Evaluating the Ergonomics of Flexible Ureteroscopy.

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Ludwig, Wesley W; Lee, Gyusung; Ziemba, Justin B; Ko, Joan S; Matlaga, Brian R

2017-10-01

To date, the ergonomics of flexible ureteroscopy (URS) have not been well described. We performed a study to assess the biomechanical stresses on urologists performing URS and to investigate the effect of ureteroscope type on these parameters. Electromyography (EMG) was used to quantify the activation level of muscle groups involved in URS. Surface EMG electrodes (Delsys, Boston, MA) were placed on the right and left thenar, flexor carpi ulnaris (FCU), extensor carpi ulnaris (ECU), biceps, triceps, and deltoid. Three endoscopes were studied: single-use digital (Boston Scientific LithoVue), reusable digital (Karl Storz Flex-X c ), and reusable fiber-optic (Karl Storz Flex-X 2 ). Each ureteroscope was used to perform a set sequence of navigation and procedural tasks in a training model. EMG data were processed and normalized to compare the maximum voluntary contractions between muscle groups. Cumulative muscular workload (CMW) and average muscular work per second (AWS) were used for comparative analysis. For navigational tasks, CMW and AWS were greatest for the ECU, followed in descending order by right and left thenar, FCU, biceps, deltoid, and triceps. For procedural tasks, CMW and AWS were greatest for the right thenar, followed in descending order by the left thenar, ECU, FCU, triceps, biceps, and deltoid. During navigational tasks, both LithoVue and Flex-X c had lower CMWs for every muscle group than Flex-X 2 (p ergonomics of URS. Both the single-use and reusable digital ureteroscopes have similar profiles, and both have significantly better ergonomic metrics than the reusable fiber-optic ureteroscope.

Extracorporeal shockwave lithotripsy vs. percutaneous nephrolithotomy vs. flexible ureterorenoscopy for lower-pole stones

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Knoll, Thomas; Buchholz, Noor; Wendt-Nordahl, Gunnar

2012-01-01

Objectives To review previous reports and discuss current trends in extracorporeal shockwave lithotripsy (ESWL), percutaneous nephrolithotomy (PCNL) and ureterorenoscopy (URS). ESWL was recommended as the first-line treatment for small and intermediate-sized stones in the lower pole, while it is the standard treatment for large stones. However, the stone clearance rate after ESWL seems to be lower than that of stones in other locations. This seems to result from a lower rate of fragment passage, due to anatomical factors. Methods Reports on urinary stone disease were reviewed, assessing only publications in peer-reviewed, Medline-listed journals in the English language (publication years 1990–2011). Results Recent experience with flexible URS (fURS) for intrarenal stones showed that excellent stone-free rates can be achieved. With increasing experience and technically improved equipment, fURS has become an alternative to ESWL for small and intermediate-sized renal stones. Furthermore, several authors reported successful retrograde treatment for large renal stones, proposing fURS as an alternative to PCNL. However, the major drawbacks are long operating times and commonly, staged procedures, which is why PCNL remains the method of choice for such stones. Conclusions Considering the currents trends and evidence, the 2012 update of the European Association of Urology Guidelines on Urolithiasis has upgraded the endourological treatment of kidney stones. Individual factors such as body habitus, renal anatomy, costs and patient preference must be considered. PMID:26558046

Ureteroscopic holmium laser cutting for inadvertently sutured drainage tube (report of five cases).

Science.gov (United States)

Gao, Xu; Lu, Xin; Ren, Shancheng; Xu, Chuanliang; Sun, Yinghao

2008-07-01

The aim of this paper is to report a simple solution for inadvertently sutured drainage tube after urological surgery and discuss the different managements according to different types of this embarrassing complication. From September 2001 to January 2007, five inadvertently sutured drainage tubes were treated with ureteroscopic holmium laser cutting for the suture. All drainage tubes were removed after the operation without other complications. Holmium laser cutting via ureteroscope is a simple solution for the embarrassing problem of inadvertently sutured drainage tube. It can save the patient from undergoing another open surgery.

Performance of Single-Use FlexorVue vs Reusable BoaVision Ureteroscope for Visualization of Calices and Stone Extraction in an Artificial Kidney Model.

Science.gov (United States)

Schlager, Daniel; Hein, Simon; Obaid, Moaaz Abdulghani; Wilhelm, Konrad; Miernik, Arkadiusz; Schoenthaler, Martin

2017-11-01

To evaluate and compare Flexor ® Vue™, a semidisposable endoscopic deflection system with disposable ureteral sheath and reusable visualization source, and a nondisposable fiber optic ureteroscope in a standard in vitro setting. FlexorVue and a reusable fiber optic flexible ureteroscope were each tested in an artificial kidney model. The experimental setup included the visualization of colored pearls and the extraction of calculi with two different extraction devices (NCircle ® and NGage ® ). The procedures were performed by six experienced surgeons. Visualization time, access to calices, successful stone retraction, and time required were recorded. In addition, the surgeons' workload and subjective performance were determined according to the National Aeronautics and Space Administration-task load index (NASA-TLX). We referred to the Likert scale to assess maneuverability, handling, and image quality. Nearly all calices (99%) were correctly identified using the reusable scope, indicating full kidney access, whereas 74% of the calices were visualized using FlexorVue, of which 81% were correctly identified. Access to the lower poles of the kidney model was significantly less likely with the disposable device, and time to completion was significantly longer (755 s vs 153 s, p NASA-TLX scores were significantly higher using FlexorVue. The conventional reusable device also demonstrated superior maneuverability, handling, and image quality. FlexorVue offers a semidisposable deflecting endoscopic system allowing basic ureteroscopic and cystoscopic procedures. For its use as an addition or replacement for current reusable scopes, it requires substantial technical improvements.

Influence of Pelvicaliceal Anatomy on Stone Clearance After Flexible Ureteroscopy and Holmium Laser Lithotripsy for Large Renal Stones.

Science.gov (United States)

Inoue, Takaaki; Murota, Takashi; Okada, Shinsuke; Hamamoto, Shuzo; Muguruma, Kouei; Kinoshita, Hidefumi; Matsuda, Tadashi

2015-09-01

This study was performed to evaluate the impact of pelvicaliceal anatomy on stone clearance in patients with remnant fragments in the lower pole after flexible ureteroscopy and holmium laser lithotripsy (fURSL) for renal stones >15 mm. This retrospective study included 67 patients with radiopaque residual fragments (>2 mm) in the lower pole after fURSL for large renal stones (>15 mm). The preoperative infundibular length (IL), infundibular width (IW), infundibulopelvic angle (IPA), and caliceal pelvic height (CPH) were measured using intravenous urography. Multivariate analysis was performed to determine whether any of these measurements affected stone clearance. Of the 67 patients, 55 (82.1%) were stone free (SF) 3 months after fURSL. The anatomic factors significantly favorable for an SF status were a short IL, broad IW, wide IPA, and low CPH. On multivariate analysis, the IPA had a significant influence on an SF status after fURSL (p=0.010). An IPA renal stones according to our multivariate analysis. Additional studies are required to further evaluate the characteristics of the pelvicaliceal anatomy influencing stone clearance.

Office flexible cystoscopy.

Science.gov (United States)

Kavoussi, L R; Clayman, R V

1988-11-01

Since the development of the first purpose-built flexible cystoscope in 1984, flexible cystoscopy has become an accepted diagnostic and therapeutic modality. Indeed, it is estimated that more than 10 per cent of practicing urologists are already familiar with this technology. The flexible cystoscope has markedly extended the urologist's ability to examine the bladder, and it has become a valuable adjunct to the rigid cystoscope. Although the operation of this instrument is vastly different from that of its rigid counterpart, with practice, the technique can be learned. After experience is obtained with diagnostic flexible cystoscopy, the urologist will likely prefer this new instrument for bladder inspection, as it provides for a more thorough yet less morbid and less expensive examination. In the future, the development of improved and smaller instrumentation will further extend the therapeutic indications for flexible cystoscopy. Indeed, advances in laser technology are already providing the urologist with 300- to 600-micron (0.9 to 1.8F) flexible probes capable of incision (KTP laser), fulguration (Nd:YAG laser), and stone disintegration (tunable dye laser). Lastly, the skills obtained in using the flexible cystoscope are all readily applicable to the development of dexterity with the already available flexible nephroscope and the more recently developed flexible ureteroscope.

Nurse-Initiated Telephone Follow Up after Ureteroscopic Stone Surgery.

Science.gov (United States)

Tackitt, Helen M; Eaton, Samuel H; Lentz, Aaron C

2016-01-01

This article presents findings of a quality improvement (QI) project using the DMAIC (define, measure, analyze, improve, and control) model designed to decrease the rate of emergency department (ED) visits and nurse advice line calls after ureteroscopic stone surgery. Results indicated that nurse-initiated follow- up phone calls can decrease ED visits.

Flexible ureterorenoscopy (F-URS) with holmium laser versus extracorporeal shock wave lithotripsy (ESWL) for treatment of renal stone <2 cm: a meta-analysis.

Science.gov (United States)

Mi, Yuanyuan; Ren, Kewei; Pan, Haiyan; Zhu, Lijie; Wu, Sheng; You, Xiaoming; Shao, Hongbao; Dai, Feng; Peng, Tao; Qin, Feng; Wang, Jian; Huang, Yi

2016-08-01

The objective of the study was to systematically review the efficacy and safety of flexible ureterorenoscopy (F-URS) with holmium laser versus extracorporeal shock wave lithotripsy (ESWL) for the treatment of renal stone ESWL (WMD = 2.13, 95 % CI 1.13-4.00, P = 0.02). F-URS is associated with higher SFR, lower APR and RR than ESWL. F-URS is a safe and effective procedure. It can successfully treat patients with stones for 1-2 cm, especially for lower pole stone, without increasing complications, operative time and hospital stay. F-URS can be used as an alternative treatment to ESWL in selected cases with larger renal stones. However, further randomized trials are needed to confirm these findings.

Assessment of validity of an OSATS for cystoscopic and ureteroscopic cognitive and psychomotor skills.

Science.gov (United States)

Kishore, Thekke Adiyat; Pedro, Renato N; Monga, Manoj; Sweet, Robert M

2008-12-01

The purpose of the study was to assess the construct validity of an Objective Structured Assessment of Technical Skills (OSATS) developed for cystoscopic and ureteroscopic cognitive and psychomotor skills. An OSATS was designed based on a 14-point comprehensive curriculum prepared by two experts that targeted both cognitive and psychomotor cystoscopic and ureteroscopic skills. Ten urology residents from a single institution with different levels of training were assessed on a series of stations that targeted these skills. Evaluation of cognitive skills was done via a written examination, and psychomotor skills assessment was done by experts using both subjective and objective metrics. Twelve of 15 cognitive tasks and 5 of 5 psychomotor tasks demonstrated construct validity with correlation coefficient (r) more than .75. All three of the cognitive tasks that failed to initially demonstrate validity did so on editorial revision and restructuring of the questions. Our cystoscopic and ureteroscopic OSATS showed excellent construct validity for our population of residents, and we have incorporated it into our urologic skills curriculum.

Laser lithotripsy with the Ho:YAG laser: fragmentation process revealed by time-resolved imaging

Science.gov (United States)

Schmidlin, Franz R.; Beghuin, Didier; Delacretaz, Guy P.; Venzi, Giordano; Jichlinski, Patrice; Rink, Klaus; Leisinger, Hans-Juerg; Graber, Peter

1998-07-01

Improvements of endoscopic techniques have renewed the interest of urologists in laser lithotripsy in recent years. Laser energy can be easily transmitted through flexible fibers thereby enabling different surgical procedures such as cutting, coagulating and lithotripsy. The Ho:YAG laser offers multiple medical applications in Urology, among them stone fragmentation. However, the present knowledge of its fragmentation mechanism is incomplete. The objective was therefore to analyze the fragmentation process and to discuss the clinical implications related to the underlying fragmentation mechanism. The stone fragmentation process during Ho:YAG laser lithotripsy was observed by time resolved flash video imaging. Possible acoustic transient occurrence was simultaneously monitored with a PVDF-needle hydrophone. Fragmentation was performed on artificial and cystine kidney stones in water. We observed that though the fragmentation process is accompanied with the formation of a cavitation bubble, cavitation has only a minimal effect on stone fragmentation. Fragment ejection is mainly due to direct laser stone heating leading to vaporization of organic stone constituents and interstitial water. The minimal effect of the cavitation bubble is confirmed by acoustic transients measurements, which reveal weak pressure transients. Stone fragmentation with the Holmium laser is the result of vaporization of interstitial (stone) water and organic stone constituents. It is not due to the acoustic effects of a cavitation bubble or plasma formation. The fragmentation process is strongly related with heat production thereby harboring the risk of undesired thermal damage. Therefore, a solid comprehension of the fragmentation process is needed when using the different clinically available laser types of lithotripsy.

Intracorporal Alexandrite-laser lithotripsy in the treatment of ureteral calculi

Science.gov (United States)

Zumbe, Juergen; Fischer, Hermann; Kimont, Hans-Georg; Kierfeld, Gerd

1994-02-01

Extracorporal shock wave lithotripsy (ESWL) is the standard therapy in the treatment of urinary calculi. the high rate of fragmentation and simultaneous stone selectivity makes laser lithotripsy an alternative method in the treatment of obstructing ureteral calculi. In comparison to the success rate of ESWL, laser lithotripsy as a minimally invasive endoscopic procedure seems to be superior in disintegrating calculi in the distal ureter. Together with the advance of miniaturized semiflexible endoscopes, intracorporal laser lithotripsy presents a new aspect in the treatment of urinary calculi.

Urolithiasis in Nairobi, Kenya | Ngugi | East African Medical Journal

African Journals Online (AJOL)

patients had PCNL; 18 as the first procedure and 5 after failed ESWL. Fifty-one patients had ureteroscopic. Management: Fourty seven had laser or pneumatic lithotripsy while four had stone removal by Dormia basket. Seven patients had bladder calculi managed by either cystolitholapaxy or forceps retrieval. Conclusions: ...

Superior Mesenteric Artery Dissection after Extracorporeal Shockwave Lithotripsy

Directory of Open Access Journals (Sweden)

Christos Bakoyiannis

2012-01-01

Full Text Available The use of shockwave lithotripsy is currently the mainstay of treatment in renal calculosis. Several complications including vessel injuries have been implied to extracorporeal shockwave lithotripsy. We report an isolated dissection of the superior mesenteric artery in a 60-year-old male presenting with abdominal pain which occurred three days after extracorporeal shockwave lithotripsy. The patient was treated conservatively and the abdominal pain subsided 24 hours later. The patient's history, the course of his disease, and the timing may suggest a correlation between the dissection and the ESWL.

Feasibility and outcome of emergency ureteroscopic removal of ...

African Journals Online (AJOL)

W. Shabana

2016-07-30

Jul 30, 2016 ... ment of a ureteral catheter or a nephrostomy tube for pain relief, followed by definite treatment .... Indian J Urol 2008;24(4. (October–December)):461–6. ... therapy after extracorporeal shock wave lithotripsy. Eur Urol Suppl.

Comparison of pneumatic and laser lithotripsy in the treatment of pediatric ureteral stones.

Science.gov (United States)

Atar, Murat; Bodakci, Mehmet Nuri; Sancaktutar, Ahmet Ali; Penbegul, Necmettin; Soylemez, Haluk; Bozkurt, Yasar; Hatipoglu, Namik Kemal; Cakmakci, Suleyman

2013-06-01

To compare the effectiveness and safety of pneumatic and holmium:YAG laser lithotripters in the treatment of pediatric ureterolithiasis. Medical records of patients treated using pneumatic (PL) (n = 29) or laser (LL) (n = 35) lithotripter between 2009 and 2011 were retrospectively analysed. The patients were evaluated with respect to age, gender, stone size, complications, and stone-free rates 1 month after the operation. For the PL and LL groups, mean ages (8.8 ± 3.4 and 8.3 ± 3.5 years), male/female ratios (19:10 and 22:13) and stone locations were similar (p > 0.05). Mean stone sizes were 55.6 mm2 and 47.6 mm2 in the PL and LL group, respectively, with no statistically significant difference (p = 0.850). Mean operative times were 20.5 min in the PL group and 25.2 min in the LL group, with a statistically significant difference (p = 0.020). Stone-free rates 1 month after intervention were 79% in the PL group and 97% in the LL group (p = 0.022). Stone migration was detected in the PL group (n = 6) and in the LL group (n = 1). No major complication was found in either group. In the ureteroscopic treatment of pediatric ureterolithiasis, both pneumatic and laser lithotripters are effective and successful. However, laser lithotripsy has a higher stone-free rate and lower complication rate. Copyright © 2012 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.

Should flexible ureteroscope be added to our armamentarium to treat stone disease?

Directory of Open Access Journals (Sweden)

Anand Dharaskar

2008-01-01

Full Text Available The field of Urology in Medicine has witnessed tremendous advancement in technology and in accordance with it. Endourology has taken a leap ahead in terms of stone management. Most of the stones could be treated with semi-rigid ureteroscopy, percutaneous nephrolithotomy (PNL and ESWL and some would need Flexible ureteroscopy. Flexible ureteroscopy has been primarily indicated to treat ESWL resistant renal stones but with changes in the technology of incorporating secondary active deflection and availability of laser fibres, its horizon for indications to treat stones is being widened. Though Flexible ureteroscopy is being used to treat stones of various sizes and locations, its cost effectiveness is debatable. Should it be used ubiquitously to treat stones amenable to PNL or ESWL is a big question we need to answer. As of now true indications of Flexible ureteroscopy are limited and there is an urgent need for a randomized trial to compare its efficacy with ESWL and PNL for renal and upper ureteric stones.

Extracorporeal shock wave lithotripsy of biliary and pancreatic stones

NARCIS (Netherlands)

R. den Toom (Rene)

1993-01-01

textabstractThe aim of the study was to answer the following questions: Is extracorporeal shock wave lithotripsy for gallbladder stones a safe and effective therapy? (Chapter 2) Is simultaneous treatment with extracorporeal shock wave lithotripsy and the solvent methyl te.rt-butyl ether feasible,

Increased Risk of New-Onset Hypertension After Shock Wave Lithotripsy in Urolithiasis: A Nationwide Cohort Study.

Science.gov (United States)

Huang, Shi-Wei; Tsai, Chung-You; Wang, Jui; Pu, Yeong-Shiau; Chen, Pei-Chun; Huang, Chao-Yuan; Chien, Kuo-Liong

2017-10-01

Although shock wave lithotripsy is minimally invasive, earlier studies argued that it may increase patients' subsequent risk of hypertension and diabetes mellitus. This study evaluated the association between shock wave lithotripsy and new-onset hypertension or diabetes mellitus. The Taiwanese National Health Insurance Research Database was used to identify 20 219 patients aged 18 to 65 years who underwent the first stone surgical treatment (shock wave lithotripsy or ureterorenoscopic lithotripsy) between January 1999 and December 2011. A Cox proportional model was applied to evaluate associations. Time-varying Cox models were applied to evaluate the association between the number of shock wave lithotripsy sessions and the incidence of hypertension or diabetes mellitus. After a median follow-up of 74.9 and 82.6 months, 2028 and 688 patients developed hypertension in the shock wave lithotripsy and ureterorenoscopic lithotripsy groups, respectively. Patients who underwent shock wave lithotripsy had a higher probability of developing hypertension than patients who underwent ureterorenoscopic lithotripsy, with a hazard ratio of 1.20 (95% confidence interval, 1.10-1.31) after adjusting for covariates. The risk increased as the number of shock wave lithotripsy sessions increased. However, the diabetes mellitus risk was similar in the shock wave lithotripsy and ureterorenoscopic lithotripsy groups. Furthermore, the hazard ratio did not increase as the number of shock wave lithotripsy sessions increased. Shock wave lithotripsy consistently increased the incidence of hypertension on long-term follow-up. Therefore, alternatives to urolithiasis treatment (eg, endoscopic surgery or medical expulsion therapy) could avoid the hypertension risk. Furthermore, avoiding multiple sessions of shock wave lithotripsy could also evade the hypertension risk. © 2017 American Heart Association, Inc.

Bubble Dynamics in Laser Lithotripsy

International Nuclear Information System (INIS)

Mohammadzadeh, Milad; Mercado, Julian Martinez; Ohl, Claus-Dieter

2015-01-01

Laser lithotripsy is a medical procedure for fragmentation of urinary stones with a fiber guided laser pulse of several hundred microseconds long. Using high-speed photography, we present an in-vitro study of bubble dynamics and stone motion induced by Ho:YAG laser lithotripsy. The experiments reveal that detectable stone motion starts only after the bubble collapse, which we relate with the collapse-induced liquid flow. Additionally, we model the bubble formation and dynamics using a set of 2D Rayleigh-Plesset equations with the measured laser pulse profile as an input. The aim is to reduce stone motion through modification of the temporal laser pulse profile, which affects the collapse scenario and consequently the remnant liquid motion. (paper)

Differences in Ureteroscopic Stone Treatment and Outcomes for Distal, Mid-, Proximal, or Multiple Ureteral Locations

DEFF Research Database (Denmark)

Perez Castro, Enrique; Osther, Palle J S; Jinga, Viorel

2014-01-01

Ureteroscopy has traditionally been the preferred approach for treatment of distal and midureteral stones, with shock wave lithotripsy used for proximal ureteral stones.......Ureteroscopy has traditionally been the preferred approach for treatment of distal and midureteral stones, with shock wave lithotripsy used for proximal ureteral stones....

Treatment of distal ureteric stones-comparative efficacy of transureteral pneumatic lithotripsy and extracorporeal shock wave lithotripsy

International Nuclear Information System (INIS)

Wazir, B.G.; Nawaz, A.; Orakzai, A.N.

2015-01-01

Ureteric stones greater than 6mm require intervention. Extracorporeal shockwave lithotripsy (ESWL) and ureteroscopy (URS) with intra-corporeal lithotripsy (ICL) are two least invasive therapies. Both show acceptable stone clearance. What should be the first line of treatment in distal ureteric stones. We conducted this study to compare the efficacy of ESWL and pneumatic ICL in order to develop clear cut treatment guidelines. Methods: This randomized control trial was conducted at Institute of Kidney Diseases, Peshawar from June 2011 to June 2012. Two hundred and twenty-four patients with distal ureteric stones 6-12 mm in size were included. Patients were randomized into two groups. Group-A patients were treated with URS plus ICL and Group-B with ESWL. Patients were evaluated for stone clearance after 2 weeks, with X-ray KUB and ultrasound. All the data were recorded in a proforma and analysed in SPSS 10. Fisher's exact test was applied to compare the efficacy and a p-value of 0.05 was considered significant. Results: Out of 112 patients in Group-A, 75 (67%) were males and 37 (33%) were females while in Group-B 79 (70.5%) were males and 33 (29.5%) were females. The mean age in Group-A was, 48.73 ± 16.23 years whereas it was 6 ± 14.58 years in Group-B. Overall, mean age was 47.36 ± 15.4 years. Mean stone size was 9.18 ± 1.6 mm. At follow up (2 weeks post-operative) URS with ICL was successful in 101 (90.2%) patients while ESWL was successful in 75 (67%) patients (p-value=0.0001). Conclusion: Extracorporeal shockwave lithotripsy shows acceptable stone clearance but ureteroscopy with intra-corporeal lithotripsy shows superior results in distal ureteric stones. (author)

Calculus migration characterization during Ho:YAG laser lithotripsy by high-speed camera using suspended pendulum method.

Science.gov (United States)

Zhang, Jian James; Rajabhandharaks, Danop; Xuan, Jason Rongwei; Chia, Ray W J; Hasenberg, Thomas

2017-07-01

Calculus migration is a common problem during ureteroscopic laser lithotripsy procedure to treat urolithiasis. A conventional experimental method to characterize calculus migration utilized a hosting container (e.g., a "V" grove or a test tube). These methods, however, demonstrated large variation and poor detectability, possibly attributed to the friction between the calculus and the container on which the calculus was situated. In this study, calculus migration was investigated using a pendulum model suspended underwater to eliminate the aforementioned friction. A high-speed camera was used to study the movement of the calculus which covered zero order (displacement), first order (speed), and second order (acceleration). A commercialized, pulsed Ho:YAG laser at 2.1 μm, a 365-μm core diameter fiber, and a calculus phantom (Plaster of Paris, 10 × 10 × 10 mm 3 ) was utilized to mimic laser lithotripsy procedure. The phantom was hung on a stainless steel bar and irradiated by the laser at 0.5, 1.0, and 1.5 J energy per pulse at 10 Hz for 1 s (i.e., 5, 10, and 15 W). Movement of the phantom was recorded by a high-speed camera with a frame rate of 10,000 FPS. The video data files are analyzed by MATLAB program by processing each image frame and obtaining position data of the calculus. With a sample size of 10, the maximum displacement was 1.25 ± 0.10, 3.01 ± 0.52, and 4.37 ± 0.58 mm for 0.5, 1, and 1.5 J energy per pulse, respectively. Using the same laser power, the conventional method showed <0.5 mm total displacement. When reducing the phantom size to 5 × 5 × 5 mm 3 (one eighth in volume), the displacement was very inconsistent. The results suggested that using the pendulum model to eliminate the friction improved sensitivity and repeatability of the experiment. A detailed investigation on calculus movement and other causes of experimental variation will be conducted as a future study.

Extracorporeal shock-wave lithotripsy as an adjunct to biliary interventional procedures

International Nuclear Information System (INIS)

Zeman, R.K.; Garra, B.S.; Matsumoto, A.H.; Teitelbaum, G.P.; Barth, K.H.; Cattau, E.L.; Davros, W.J.; McClennan, B.L.; Picus, D.; Paushter, D.M.

1989-01-01

This paper reviews the records of nine patients undergoing extracorporeal shock wave lithotripsy (ESWL) of bile duct stones as an adjunct to other biliary intervention. Lithotripsy was successful in producing fragmentation in seven of nine patients. Keeping the duct mildly distended with contrast medium, distributing the shock waves over the stone(s) by taking advantage of respiratory excursion, and pinning stone fragments with balloon catheters facilitated fragmentation. Six patients underwent duct manipulation (stricture dilation, fragment extraction) within 24 hours of ESWL, suggesting that immediate instrumentation is safe in conjunction with lithotripsy

Audiovisual distraction reduces pain perception during shockwave lithotripsy.

Science.gov (United States)

Marsdin, Emma; Noble, Jeremy G; Reynard, John M; Turney, Benjamin W

2012-05-01

Lithotripsy is an established method to fragment kidney stones that can be performed without general anesthesia in the outpatient setting. Discomfort and/or noise, however, may deter some patients. It has been demonstrated that audiovisual distraction (AV) can reduce sedoanalgesic requirements and improve patient satisfaction in nonurologic settings, but to our knowledge, this has not been investigated with lithotripsy. This randomized controlled trial was designed to test the hypothesis that AV distraction can reduce perceived pain during lithotripsy. All patients in the study received identical analgesia before a complete session of lithotripsy on a fixed-site Storz Modulith SLX F2 lithotripter. Patients were randomized to two groups: One group (n=61) received AV distraction via a wall-mounted 32″ (82 cm) television with wireless headphones; the other group (n=57) received no AV distraction. The mean intensity of treatment was comparable in both groups. Patients used a visual analogue scale (0-10) to record independent pain and distress scores and a nonverbal pain score was documented by the radiographer during the procedure (0-4). In the group that received AV distraction, all measures of pain perception were statistically lower. The patient-reported pain score was reduced from a mean of 6.1 to 2.4 (P<0.0001), and the distress score was reduced from a mean of 4.4 to 1.0 (P=0.0001). The mean nonverbal score recorded by the radiographer was reduced from 1.5 to 0.5 (<0.0001). AV distraction significantly lowered patients' reported pain and distress scores. This correlated with the nonverbal scores reported by the radiographer. We conclude that AV distraction is a simple method of improving acceptance of lithotripsy and optimizing treatment.

Efficacy of the lithotripsy in treating lower pole renal stones.

Science.gov (United States)

Cui, Helen; Thomee, Eeke; Noble, Jeremy G; Reynard, John M; Turney, Benjamin W

2013-06-01

Use of extracorporeal lithotripsy is declining in North America and many European countries despite international guidelines advocating it as a first-line therapy. Traditionally, lithotripsy is thought to have poor efficacy at treating lower pole renal stones. We evaluated the success rates of lithotripsy for lower pole renal stones in our unit. 50 patients with lower pole kidney stones ≤15 mm treated between 3/5/11 and 19/4/12 were included in the study. Patients received lithotripsy on a fixed-site Storz Modulith SLX F2 lithotripter according to a standard protocol. Clinical success was defined as stone-free status or asymptomatic clinically insignificant residual fragments (CIRFs) ≤3 mm at radiological follow-up. The mean stone size was 7.8 mm. The majority of stones (66 %) were between 5 and 10 mm. 28 % of stones were between 10 and 15 mm. For solitary lower pole stones complete stone clearance was achieved in 63 %. Total stone clearance including those with CIRFs was achieved in 81 % of patients. As expected, for those with multiple lower pole stones the success rates were lower: complete clearance was observed in 39 % and combined clearance including those with CIRFs was 56 %. Overall, complete stone clearance was observed in 54 % of patients and clearance with CIRFs was achieved in 72 % of patients. Success rate could not be attributed to age, stone size or gender. Our outcome data for the treatment of lower pole renal stones (≤15 mm) compare favourably with the literature. With this level of stone clearance, a non-invasive, outpatient-based treatment like lithotripsy should remain the first-line treatment option for lower pole stones. Ureteroscopy must prove that it is significantly better either in terms of clinical outcome or patient satisfaction to justify replacing lithotripsy.

Decreased renal function and hypertension are long-term complications of extracorporeal shock wave lithotripsy

International Nuclear Information System (INIS)

Williams, C.M.; Kaude, J.V.; Newman, R.C.; Peterson, J.C.; Thomas, W.C.

1987-01-01

Quantitative radionuclide renography performed in 21 patients 17-21 months after extracorporeal shock wave lithotripsy showed a significant decrease in the percentage of effective renal plasma flow (%ERPF) of the treated kidney; in five (24%) patients the %ERPF had decreased by more than 5 percentage units. In seven (8%) of 91 patients sustained hypertension developed that required pharmacologic treatment after lithotripsy. Decreased %ERPF of a treated kidney and hypertension may be related to a Page kidney or similar process resulting from renal trauma and hemorrhage occurring as a side effect of lithotripsy. Hypertension is an important complication of lithotripsy in about 8% of patients

Safety and efficacy of transurethral pneumatic lithotripsy for bladder calculi in children

International Nuclear Information System (INIS)

Khosa, A.S.; Hussain, M.; Hussain, M.

2012-01-01

Objective: To determine the safety and efficacy of transurethral pneumatic lithotripsy for bladder calculi in children. Method: The study included 100 children up to 15 years of age undergoing pneumatic cystolithoclast for bladder stones. The descriptive study was conducted from September 2006 to February 2007 at the Sindh Institute of Urology and Transplantation, Karachi. The inclusion criteria was children up to 15 years of age with a bladder stone of up to 3 cm, pre-operative negative urine culture, no coagulopathy and fit for general anaesthesia. An X-ray and ultrasound of Kidney and Urinary Bladder (KUB) was mandatory. The procedure was done under general anaesthesia with a single dose of pre-operative antibiotic. A mini-scope of 4 FR or a semi-rigid ureteroscope of 7/8.5 FR with pneumatic wolf lithoclast was used for the fragmentation of stones. Duration of procedure, any per-operative and post-operative complications and the duration of hospital stay were recorded. Post-operatively, the patient underwent ultrasound Kidney and Urinary Bladder at the first follow-up to assess stone clearance after one week. Result: Mean patients age was 4.95+-3.3 years. The male-to-female ratio was 11.5: 1 The mean hospital stay was 9.2 +- 2.5 hours. The mean operating time was 25 (10 -65) minutes. Ten (10%) patients developed minor complications out of which 5 (5%) developed haematuria and 4 (4%) developed difficulty in passing urine. One (1%) of the patients developed post-operative retention of urine. All the patients were stone free after the procedure. Conclusion: The transurethral pneumatic lithoclast is very effective and safe in children with bladder stones up to 3 cm. (author)

EXTRACORPOREAL SHOCK WAVE LITHOTRIPSY AS ...

African Journals Online (AJOL)

Objective To evaluate extracorporeal shock wave lithotripsy (ESWL) as a monotherapy for urolithiasis in patients with solitary kidney and to determine the factors that may affect its results. Patients and Methods Using the Dornier MFL 5000 lithotriptor, 106 patients with solitary kidney (80 men and 26 women) were treated for ...

Acoustic sensing of renal stone fragmentation in extracorporeal shockwave lithotripsy

OpenAIRE

Fedele, Fiammetta

2008-01-01

This thesis describes the research carried out by the author on the exploitation of acoustic emissions detected during extracorporeal shockwave lithotripsy (a non-invasive procedure for the treatment of urinary stones) to develop a new diagnostic system. The work formed part of a research project on lithotripsy undertaken by the University of Southampton in collaboration with Guy's and St Thomas' NHS Foundation Trust (London) and a UK based company, Precision Acoustics Ltd (Dorche...

Treatment philosophy and retreatment rates following piezoelectric lithotripsy.

Science.gov (United States)

Fegan, J; Camp, L A; Wilson, W T; Miller, G L; Preminger, G M

1993-01-01

Second generation lithotriptors offer the advantage of anesthesia-free fragmentation of renal and ureteral calculi but they frequently require multiple treatments to attain a stone-free status. However, excessive single lithotripsy sessions or multiple treatments may be associated with significant damage to the kidney. For some clinicians a common treatment philosophy involves evaluation of serial plain abdominal films every 24 hours after lithotripsy and immediate retreatment of all patients with incomplete fragmentation. To avoid unnecessary retreatments and, thus, minimize potential renal damage, we prospectively evaluated 100 patients undergoing lithotripsy on a Wolf Piezolith 2300 device. Patients were routinely treated with 4,000 shocks at 1,100 bar. Serial plain abdominal films were obtained at 1 day and 2 weeks after lithotripsy. The need for retreatment was determined by the plain abdominal film results. Additional therapy was considered necessary if there was no stone fragmentation or if residual fragments measured greater than 4 mm. Of the patients whose plain abdominal film at 24 hours indicated the need for a repeat treatment 43% were stone-free on the 2-week film. Thus, these patients were spared an unnecessary treatment by allowing adequate time for the stone fragments to pass spontaneously. Our data suggest that repeat treatments on second generation lithotriptors should not be performed within 24 hours. Rather, the patient should be reevaluated at least 1 to 2 weeks later to avoid unnecessary retreatment with the attendant potential for renal injury. In addition, when comparing the retreatment rates of various lithotriptors, one should also consider the treatment philosophy used at the particular institution and the timing of the radiographic studies used to determine the stone-free status.

Gallstone fragmentation by control electrohydraulic lithotripsy

International Nuclear Information System (INIS)

Tung, G.A.; Mueller, P.R.; Brink, J.A.; Saini, S.; Picus, D.; Simeone, J.F.; Ferrucci, J.T.

1989-01-01

The authors have performed in vitro contact electrohydraulic lithotripsy (EHL) of 100 gallstones > 10 mm in diameter to identify physical and technical factors that affect fragmentation success. Ninety-one of 100 stones were fragmented with a 3-F electrode (average, seven shocks; range, 1--42); only 12 stones were fragmented with a single shock. Of the nine stones refractory to 50 shocks, four were > 30 mm in diameter and five stones were densely calcified. The most important variable determining power requirements for fragmentation was gallstone size (R = .58), but radiographic calcification of gallstones was also important (R = .47). Stones < 15 mm tended to produce fragments of left-angle 2 mm; stones right-angle 20 mm tended to produce two to five large discrete fragments (P , .05). In addition, lithotripsy could be conducted equally well in 1:1 dilute diatrizoate contrast agent as in 1:6 normal saline, suggesting that contact EHL could be performed under fluoroscopy

Outcome of Extracorporeal Shock Wave Lithotripsy

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B Shrestha

2010-03-01

Full Text Available NTRODUCTION: Extracorporeal Shock Wave Lithotripsy is an effective noninvasive method to treat urolithiasis. This study aims to evaluate itsoutcome and determine appropriate management strategies for urolithiasis. METHODS: It was a prospective study which included one hundred patients who underwent ESWL for the management of solitary urolithiasis during a period of eight months (December 2007-August 2008. Status of stone and complications were observed and managed accordingly within a period of six postoperative weeks. RESULTS: Out of 100 patients, 93% had complete clearance of stone by the end of six postoperative weeks. Seven percent of the patients required adjunct invasive intervention including open surgery in 3%. Number of sessions of ESWL was found to increase as the size of stone increased. However, in three patients stones were completely refractory to ESWL even after two consecutive sessions. CONCLUSIONS: ESWL is highly effective noninvasive modality in the management of urolithiasis in appropriately selected patients. Keywords: double J stent, extracorporal shockwave lithotripsy, steinstrasse, ultrasonography, ureterorenoscopy.

Numerical Simulation of the Micro-explosion during Ho:YAG laser lithotripsy

International Nuclear Information System (INIS)

Yao Yucheng; Huang Chuyun; Xu Guowang; Yan Xudong; Wang Yanlin

2011-01-01

The micro-explosion during Ho:YAG laser lithotripsy may cause calculus fragmentation and migration. It plays an important role to the surgery. A numerical simulation of the micro-explosion during Ho:YAG laser lithotripsy has been developed. The explosion problem in water environment was solved by the Euler algorithm and the piecewise parabolic method (PPM) was selected in the calculation. This simulation investigated the explosion dynamics evolution in the lithotripsy area. The pressure and intensity of the calculus surface were calculated for different laser pulse energy and different distance between calculus and fiber tip. The calculation results indicate that the micro-explosion's properties are determined by the pulse energy, pulse duration and the water distance. Though Short pulse duration and large pulse energy cause high ablation efficiency, it mains more calculus retropulsion at the same time. The ideal surgery results need property laser parameters.

[Renal hematomas after extracorporeal shock-wave lithotripsy (ESWL)].

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Pastor Navarro, Héctor; Carrión López, Pedro; Martínez Ruiz, Jesús; Pastor Guzmán, José Ma; Martínez Martín, Mariano; Virseda Rodríguez, Julio A

2009-03-01

The use of fragmentation due to shock- waves as a treatment of urinary stone was one of the most important therapeutics findings in the history of urology. It's the first election treatment for most of the calculus at renal and urethral location due to the fact that it is a low invasive treatment and it has a few number of complications, but this method also has a few negative side effects, it can caused a more or less important traumatic lesion at the organs which crosses the shock-waves, including the kidney where it can caused a small contusion or renal hematoma with different resolution and treatment. We reviewed 4815 extracorporeal shock-wave lithotripsy that we performed in our department in which we found six cases with subcapsular and perirenal hematoma which we followed up and treated. After the urological complications (pain, obstruction and infection) the renal and perirenal hematic collections are the most frequent adverse effects of shock-waves used in lithotripsy, these are related to the power of energy used and patient age. Between the years 1992-2007 we performed 4.815 extracorporeal shock-wave lithotripsy finding seven cases of severe hematoma, less then 1%. Treatment of these complications is usually not aggressive though sometimes it is necessary to perform surgical drainage and even nephrectomy.

State of the art extracorporeal shock wave lithotripsy

Energy Technology Data Exchange (ETDEWEB)

Kandel, L.B. (State Univ. of New York at Stony Brook, Stony Brook, NY (US)); Harrison, L.H.; McCullough, D.L. (Wake Forest Univ. Medical Center, Winston-Salem, NC (US))

1987-01-01

This book contains 16 chapters. Some of the topics that are covered are: Extracorporeal Shock Wave Lithotripsy Development; Laser-Generated Extracorporeal Shock Wave Lithotripter; Radiation Exposure during ESWL; Caliceal Calculi; and Pediatric ESWL.

State of the art extracorporeal shock wave lithotripsy

International Nuclear Information System (INIS)

Kandel, L.B.; Harrison, L.H.; McCullough, D.L.

1987-01-01

This book contains 16 chapters. Some of the topics that are covered are: Extracorporeal Shock Wave Lithotripsy Development; Laser-Generated Extracorporeal Shock Wave Lithotripter; Radiation Exposure during ESWL; Caliceal Calculi; and Pediatric ESWL

Management of ureteric stone in pediatric patients

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Eugene Minevich

2010-01-01

Full Text Available 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.

Flexible ureterorenoscopy for lower pole stones: influence of the collecting system's anatomy.

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Jessen, Jan Peter; Honeck, Patrick; Knoll, Thomas; Wendt-Nordahl, Gunnar

2014-02-01

The impact of renal anatomy on the success rate of flexible ureterorenoscopy (fURS) for lower pole stones is less clear than it is on shock wave lithotripsy, for which it is a recognized influence factor. We analyzed safety and efficiency of fURS using modern endoscopes for lower pole stones dependent on the collecting system's configuration. We retrospectively evaluated a consecutive sample of 111 fURS for lower pole stones at our tertiary care center between January 2010 and September 2012 from our prospectively kept database. All procedures were performed with modern flexible ureterorenoscopes, nitinol baskets, holmium laser lithotripsy, and ureteral access sheaths whenever needed. The infundibular length (IL) and width (IW) and infundibulopelvic angle (IPA) were measured and the data were stratified for stone-free status and complications classified by the Clavien-Dindo scale. Univariate and multifactorial statistical analyses were performed. Correlation of operation time (OR-time) with anatomical parameters was conducted. Ninety-eight (88.3%) of the 111 patients were stone free after a single fURS. On multifactorial analysis, the stone size and IL had significant influence on the stone-free rate (SFR) (panatomy. fURS is a safe and efficient treatment option for lower pole kidney stones. A long infundibulum and a very acute IPA (anatomy.

Extracorporeal shock waves lithotripsy of urinary organs in patients with one kidney

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Zogović Jezdimir

2002-01-01

Full Text Available Extracorporeal Shock Waves Lithotripsy (ESWL is a method of choice in the treatment of lithiasis. Surgical treatment is reduced to minimum, which in our case means 1-2%. Contraindications for using this method are: blood coagulation disorders, manifest tuberculosis, pregnancy, over obesity. Thanks to appropriate indications and technique which is used in an adequate way as well as to various endurological manipulations, removal of a stone by this method is safe, trauma is minimised, which is very important for patients with one kidney. During the last three years, usually in hospital conditions, 57 patients were treated in this way. Removal of a stone was performed by Extracorporeal Shock Waves Lithotripsy as mono therapy in 30 (53% patients; Extracorporeal Shock Waves Lithotripsy by using Double-J catheter in 16 (28% patients; Extracorporeal Lithotripsy with urine derivation by percutaneous nephrostome in 11 (19% patients. Endurological methods were used in 27 patients. Disintegration of stone was performed in the proper way. Full success was reached. Two patients had incrustation of ureteral catheter which had to be removed by surgery. In two other patients with inferior function of one kidney, after brief obstruction, hemodialisis was performed. Our results confirm that this method is nonaggressive, tech nically perfect for disintegration of urineorgans stone on all levels followed by small complications which are often solved by endoscopie manipulations.

Contribution of modern lithotripsy to the practice of urology

International Nuclear Information System (INIS)

Caine, M.

1986-01-01

Modern lithotripsy, both the minimally invasive percutaneous method and the completely noninvasive extracorporeal shock wave lithotripsy (ESWL) technique, have far-reaching effects on the practice of urology. The patient is spared a painful operation and convalescence, as well as surgical trauma to the kidney. The urologist needs to familiarize himself with the new techniques and, with the percutaneous method, must guard against radiation. The hospital is involved in considerable expense in purchasing and installing the ESWL equipment, and should redistribute its facilities to take full advantage of the rapid turnover it permits. The nation gains considerably by minimizing workdays lost due to surgical operations and convalescence, and by reducing the number of patients with kidney stones who ultimately require dialysis

Flexible ureteroscopy versus percutaneous nephrolithotomy as primary treatment for renal stones 2 cm or greater

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Akar EC

2013-01-01

Full Text Available Erin Akar, Bodo E KnudsenDepartment of Urology, Ohio State University Wexner Medical Center, Columbus, OH, USAAbstract: The purpose of this review, based on the current evidence in the literature, is whether ureteroscopy (URS is a comparable primary treatment option to the current gold standard of percutaneous nephrolithotomy (PCNL for the treatment of large kidney stones 2 cm or greater. The lack of prospective randomized trials directly comparing URS and PCNL makes comparison challenging. The numerous studies are not standardized in terms of their definition of stone-free or how stone size is reported. In order to standardize comparison of results, we used a stone-free definition of <4 mm after one procedure per imaging of the author’s choice, since how each patient was imaged postoperatively was not reported. The results from the literature show that moderately large stones from 2 to 3 cm treated ureteroscopically have similar outcomes to PCNL. Stone-free rates with URS decrease when stone size is above 3 cm. Our interpretation of the literature suggests that a current limitation of URS is that multiple procedures for URS would be required to achieve comparable stone-free rates to PCNL, particularly for stones greater than 4 cm.Keywords: ureteroscopy, percutaneous nephrolithotomy, lithotripsy, urinary calculi

A clinical nomogram to predict the successful shock wave lithotripsy of renal and ureteral calculi.

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Wiesenthal, Joshua D; Ghiculete, Daniela; Ray, A Andrew; Honey, R John D'A; Pace, Kenneth T

2011-08-01

Although shock wave lithotripsy is dependent on patient and stone related factors, there are few reliable algorithms predictive of its success. In this study we develop a comprehensive nomogram to predict renal and ureteral stone shock wave lithotripsy outcomes. During a 5-year period data from patients treated at our lithotripsy unit were reviewed. Analysis was restricted to patients with a solitary renal or ureteral calculus 20 mm or less. Demographic, stone, patient, treatment and 3-month followup data were collected from a prospective database. All patients were treated using the Philips Lithotron® lithotripter. A total of 422 patients (69.7% male) were analyzed. Mean stone size was 52.3±39.3 mm2 for ureteral stones and 78.9±77.3 mm2 for renal stones, with 95 (43.6%) of the renal stones located in the lower pole. The single treatment success rates for ureteral and renal stones were 60.3% and 70.2%, respectively. On univariate analysis predictors of shock wave lithotripsy success, regardless of stone location, were age (p=0.01), body mass index (p=0.01), stone size (pstone density (pstone distance (pstone area and skin to stone distance were significant predictors with an AUC of 0.75. For ureteral calculi predictive factors included body mass index and stone size (AUC 0.70). Patient and stone parameters have been identified to create a nomogram that predicts shock wave lithotripsy outcomes using the Lithotron lithotripter, which can facilitate optimal treatment based decisions and provide patients with more accurate single treatment success rates for shock wave lithotripsy tailored to patient specific situations. Copyright © 2011 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

[Usefullness of the StoneBreaker lithotripter for percutaneous nephrolithotomy].

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del Peso, Almudena Coloma; González, Inmaculada Fernández; Gálvez, Milagros Jiménez; Abad, Pablo Garrido; Fajardo, Gloria Bocardo; Fernández, Luis Miguel Herranz; Arjona, Manuel Fernández; Torres, Lorenzo Herrero; Sanz, Ignacio Pereira

2008-01-01

Throughout the history, many devices have been used for breaking urinary tract stones. StoneBreaker (LMA Urology, Gland, Switzerland) is a second generation of intracorporeal lithotripter, pneumatic and portable, which adds several new advantages, like effectiveness in stone fragmentation and easy handling, very useful during percutaneous lithotripsy. We report the case of a 40 year-old male patient, with a left kidney pyelic lithiasis, who was treated by percutaneous lithotripsy, under general anaesthesia, with StoneBreaker (LMA Urology, Gland, Switzerland) as lithotripter. StoneBreaker (LMA Urology, Gland, Switzerland) is a lithotripter usable with rigid and semirigid ureteroscopes, much more powerful than its predecessors. It is able to decrease the number of shocks necessary for stone fragmentation, without bigger tissue reaction. It also has a more comfortable design due to the absence of connections, and its power by replaceable carbon dioxide cartridges.

[Large calculi of the common bile duct. Value of lithotripsy].

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Lefebvre, J F; Molkhou, J M; Bonnel, D; Dazza, F; Liguory, C

1994-01-01

Certain stones need to be fragmented before being extracted via endoscopic sphincterotomy (ES). From April 1988 to December 1991, extracorporeal lithotripsy was used in this indication in 28 patients (22 females, 6 males) with a mean age of 77 +/- 20 years, using an ultrasound-guided electrohydraulic lithotriptor. Stone detection was performed after perfusion of the nasogastric tube and was easy in 20 cases (71%), difficult in 6 cases (22%) and impossible in 2 cases (7%), which could not be treated by this method. The patients had an average of 1.4 +/- 0.9 stones measuring 19.6 +/- 8 mm and received an average of 2.480 +/- 580 shock waves in a single session for 24 patients and in two sessions for 2 patients. Radiologically obvious fragmentation was achieved in 11 out of 26 cases (42%) and was found to be effective at a further extraction attempt in 4 other cases. Complete clearance of the common bile duct was achieved in 15 cases (57.7%). The size of the stones (> or power of the generator and the use of fluoroscopic rather than ultrasonographic guidance should allow an improvement of these results in the future. Because of its safety, this lithotripsy method can be proposed following failure of mechanical lithotripsy.

Patient and personnel exposure during extracorporeal lithotripsy

International Nuclear Information System (INIS)

Glaze, S.; LeBlanc, A.D.; Bushong, S.C.; Griffith, D.P.

1987-01-01

Extracorporeal shock wave lithotripsy (ESWL) has provided a nonsurgical approach to treatment of renal stones. The Dornier lithotripter uses dual image intensified x-ray systems to center the stone before treatment. Three imaging modes are offered: a fluoroscopic mode and two video spot filming modes. The average entrance exposure to the stone side of the typical patient at our facility is 2.6 X 10(-3) C kg-1 (10 R) [range: 0.5-7.7 X 10(-3) C kg-1 (2-30 R)] which is comparable and often much less than that reported for percutaneous lithotripsy. Recommendations are made for minimizing patient exposure. Scattered radiation levels in the lithotripter room are presented. We have determined that Pb protective apparel is not required during this procedure provided x-ray operation is temporarily halted should personnel be required to lean directly over the tub to attend to the patient. If the walls of the ESWL room are greater than 1.83 m (6 feet) from the tub, shielding in addition to conventional construction is not required

Patient and personnel exposure during extracorporeal lithotripsy

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Glaze, S.; LeBlanc, A.D.; Bushong, S.C.; Griffith, D.P.

1987-12-01

Extracorporeal shock wave lithotripsy (ESWL) has provided a nonsurgical approach to treatment of renal stones. The Dornier lithotripter uses dual image intensified x-ray systems to center the stone before treatment. Three imaging modes are offered: a fluoroscopic mode and two video spot filming modes. The average entrance exposure to the stone side of the typical patient at our facility is 2.6 X 10(-3) C kg-1 (10 R) (range: 0.5-7.7 X 10(-3) C kg-1 (2-30 R)) which is comparable and often much less than that reported for percutaneous lithotripsy. Recommendations are made for minimizing patient exposure. Scattered radiation levels in the lithotripter room are presented. We have determined that Pb protective apparel is not required during this procedure provided x-ray operation is temporarily halted should personnel be required to lean directly over the tub to attend to the patient. If the walls of the ESWL room are greater than 1.83 m (6 feet) from the tub, shielding in addition to conventional construction is not required.

Piezoelectric biliary lithotripsy

International Nuclear Information System (INIS)

Schulte, S.J.; Baron, R.L.; Kuyper, S.J.

1989-01-01

Two hundred gallstones from 60 patients underwent in vitro CT and lithotripsy with the EDAP LT.01. The fragmentation process was analyzed, and time to complete fragmentation (≤2 mm) was recorded. The authors report that two patterns of fragmentation were observed: central fragmentation and peripheral chipping. Gallstones from individual patients demonstrated uniform fragmentation patterns and consistent relationships between fragmentation time and stone size, shock wave frequency and power. The most important factor affecting fragmentation was gallstone size: fragmentation time correlated with the cube of the stone radius. Shock wave frequency and power directly correlated with fragmentation time. Stones from different patients showed marked differences in fragmentation time but within each patient, the relationships between fragmentation time, stone size, and shock wave frequency and power were maintained

[Clinical, ureteroscopic and photodynamic diagnosis of urothelial carcinomas of the upper tract: state-of-the art review for the yearly scientific report of the French National Association of Urology].

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Nison, L; Bozzini, G; Rouprêt, M; Traxer, O; Colin, P

2014-11-01

To propose a state-of-the art of current knowledge about clinical, ureteroscopic and photodynamic for the diagnosis of the upper urinary tract cancer (UTUC). A systematic review of the literature search was performed from the database Medline (NLM, Pubmed), focused on the following keywords: urothelial carcinomas; upper urinary tract; ureter; renal pelvis; diagnosis; fluorescence; ureteroscopy; photodynamic technique; biopsy; cytology. Gross hematuria and flank pain are the two main clinical symptoms revealing a UTUC in daily clinical practice. Urinary cystoscopy and cystoscopy are mandatory to rule out a concomittant synchronous bladder tumour. Flexible ureteroscopy has revolutionized the management of UTUC by allowing a full exploration of upper urinary tract, an endoscopi vizualization of the tumour and assessment of grade with biopsies. A flexible ureteroscopy is mandatory in diagnostic evaluation of UTUC as soon as a conservative management is being considered. New investigation technologies such as fluorescence, narrow band imaging and optical coherence tomography (± combined with ultra sound), are promising for a near future. It has to be understood that the diagnostic work-up of a UTUC has to be exhaustive and particularly the search of another urothelial carcinoma within the urinary tract. Flexible ureterosocopy has revolutionized the diagnosis and management of UTUC and belongs fully to its initial evaluation. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Shear Wave Elastographic Alterations in the Kidney After Extracorporeal Shock Wave Lithotripsy.

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Turkay, Rustu; Inci, Ercan; Bas, Derya; Atar, Arda

2018-03-01

Extracorporeal shock wave lithotripsy (ESWL) is a method used frequently for the treatment of renal stone disease. Although its safety is proven, there are still concerns about its unwanted effects on kidneys. In this prospective study, we aimed to evaluate renal tissue alterations with shear wave elastography (SWE) after ESWL. We also studied the correlation between SWE and resistive index (RI) changes. The study included 59 patients who underwent ESWL treatment for renal stone disease. We performed SWE and color Doppler ultrasonography to calculate SWE and RI values before, 1 hour after, and 1 week after lithotripsy treatment. A binary comparison was performed by the Bonferroni test. The correlation between SWE and RI values was evaluated by a Pearson correlation analysis. The patients included 26 women (44.1%) and 33 men (55.9%). Their ages ranged from 20 to 65 years (mean ± SD, 45.0 ± 1.1 years). Stone diameters ranged from 7 to 19 mm (mean, 13.0 ± 0.5 mm). There was a significant difference in SWE values before and 1 hour after lithotripsy treatment (P = .001; P  .99; P > .05). Resistive index values increased significantly 1 hour after lithotripsy treatment and returned to prelithotripsy values 1 week after treatment. In the correlation analysis, SWE and RI values were not correlated. Measurements of alterations in SWE values after ESWL can provide useful information about renal tissue injury. © 2017 by the American Institute of Ultrasound in Medicine.

Extracorporeal shockwave lithotripsy of gallbladder stones : an experimental study

NARCIS (Netherlands)

H. Vergunst (Henk)

1991-01-01

textabstractThe objective of this study was to determine the physical characteristics and biological effects of the lithotriptor to enbaoce further clinical studies on the role of ESWL in the treatment of symptomatic cholelithiasis, using a newly developed electromagnetic lithotripsy system

Extracorporeal Shock Wave Lithotripsy versus Lasertripsy For The ...

African Journals Online (AJOL)

Objectives: To compare the efficacy, cost effectiveness and safety of both ESWL and Holmium:YAG laser lithotripsy for the management of upper ureteric stones. Patients and Methods: One hundred and eight patients of various age groups and of both sexes who had primary or recurrent unilateral or bilateral upper ureteric ...

Cavitation cluster dynamics in shock-wave lithotripsy: Part I

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Arora, M.; Junge, L.; Junge, L.; Ohl, C.D.

2005-01-01

The spatiotemporal dynamics of cavitation bubble growth and collapse in shock-wave lithotripsy in a free field was studied experimentally. The lithotripter was equipped with two independently triggerable layers of piezoceramics. The front and back layers generated positive pressure amplitudes of 30

Safety and efficacy of silodosin and tadalafil in ease of negotiation of large ureteroscope in the management of ureteral stone: A prosective randomized trial.

Science.gov (United States)

Bhattar, Rohit; Jain, Vipin; Tomar, Vinay; Yadav, Sher Singh

2017-12-01

To evaluate the safety and efficacy of silodosin and tadalafil in ease of negotiation of large size ureteroscope (8/9.8 Fr) in the management of ureteral stone. Between June 2015 and May 2016, 86 patients presented with ureteral stone of size 6-15 mm were on consent randomly assigned to 1 of 3 outpatient treatment arms: silodosin (Group A), tadalafil (Group B), and placebo (Group C). After two weeks of therapy 67 patients underwent ureteroscopy, and ureteral orifice configuration, ureteroscopic negotiation, ureteral dilatation, operating time, procedural complication and drug related side effects were noted in each group. Ureteral negotiation was significantly better in Groups A (73.9%) and B (69.6%) as compared to Group C (38.1%) (p<0.01). Statistically significant difference was noted in the requirement for dilatation in Group C (71.4%) as compared to Groups A (26.1%) and B (39.1%) (p<0.01). Ureteral orifice was found to be more dilated in Groups A (69.6%) and B (60.9%) as compared to Group C (28.6%). Mean operating time was statistically lower in Groups A (35.2 min) and B (34.91 min) as compared to Group C (41.14 min) (p<0.01). Both silodosin and tadalafil not only relax ureteral smooth muscle but also help in forward propagation of large size ureteroscope (8/9.8 Fr) without any significant risk of adverse events.

SELECTIVE EVALUATION OF TWO URINARY ENZYMES (NAG AND AAP BEFORE AND AFTER UNILATERAL SHOCK WAVE LITHOTRIPSY

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M. R. Nikoobakht

2006-09-01

Full Text Available Biological effects extracorporeal shock wave lithotripsy (ESWL is not precisely known. We have evaluated two urinary enzymes activity N-acetyl-B-D-glucosamine (NAG and alanine amino peptidase (AAP before and after unilateral ESWL as markers for renal parenchymal damage. Forty eight patients with kidney stones (mean age 39 who had presented for the first time or at least one year after their previous lithotripsy underwent ESWL. Urinary specimens were collected before and after first, third and seventh days of lithotripsy and NAG, AAP were evaluated. These enzymes displayed the greatest activity 24 hours after ESWL with significant difference compared to the control group, (P < 0.05 versus 0.02. Elevation of urinary enzymes activity correlated with stone size particularly stones larger than 2 cm. These data suggest that there is some tubular and parenchymal damage induced by ESWL that needs time to get improved. The higher urinary enzyme activity in patients with larger stones ( > 2 cm is probably related to injury resulting from passage of smaller stones, produced after lithotripsy of a large stone, and it is suggested that these patients are treated with a safer procedure.

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

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Elhilali, Mostafa M; Badaan, Shadie; Ibrahim, Ahmed; Andonian, Sero

2017-06-01

To evaluate in vitro and in vivo effects of Moses technology in Holmium laser and to compare it with the Regular mode in terms of lithotripsy efficiency and laser-tissue interactions. The Lumenis ® Pulse™ P120H holmium laser system together with Moses D/F/L fibers were used to compare the Regular mode with the Moses modes in stone retropulsion by using a high-speed camera, and stone ablation efficiency. In addition, a porcine ureteroscopy model was used to assess stone fragmentation and dusting as well as laser-tissue interaction with the ureteral wall. After a laser pulse, in vitro stone displacement experiments showed a significant reduction in retropulsion when using the Moses mode. The stone movement was reduced by 50 times at 0.8 J and 10 Hz (p technology resulted in more efficient laser lithotripsy, in addition to significantly reduced stone retropulsion, and displayed a margin of safety that may result in a shorter procedural time and safer lithotripsy.

Stone retropulsion during holmium:YAG lithotripsy.

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Lee, Ho; Ryan, R Tres; Teichman, Joel M H; Kim, Jeehyun; Choi, Bernard; Arakeri, Navanit V; Welch, A J

2003-03-01

We modeled retropulsion during holmium:YAG lithotripsy on the conservation of momentum, whereby the force of ejected fragment debris off of the calculous surface should equal the force of retropulsion displacing the stone. We tested the hypothesis that retropulsion occurs as a result of ejected stone debris. Uniform calculous phantoms were irradiated with holmium:YAG energy in air and in water. Optical fiber diameter and pulse energy were varied. Motion of the phantom was monitored with high speed video imaging. Laser induced crater volume and geometry were characterized by optical coherence tomography. To determine the direction of plume laser burn paper was irradiated at various incident angles. Retropulsion was greater for phantoms irradiated in air versus water. Retropulsion increased as fiber diameter increased and as pulse energy increased (p <0.001). Crater volumes increased as pulse energy increased (p <0.05) and generally increased as fiber diameter increased. Crater geometry was wide and shallow for larger fibers, and narrow and deeper for smaller fibers. The ejected plume propagated in the direction normal to the burn paper surface regardless of the laser incident angle. Retropulsion increases as pulse energy and optical fiber diameter increase. Vector analysis of the ejected plume and crater geometry explains increased retropulsion using larger optical fibers. Holmium:YAG lithotripsy should be performed with small optical fibers to limit retropulsion.

Management of retained encrusted urethral catheter with extracorporeal shockwave lithotripsy

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Sameh Anwar Kunzman

2002-01-01

Full Text Available We report a case of non-deflating heavily encrusted Foley catheter successfully removed by extracorporeal shockwave lithotripsy (ESWL. To our knowledge this is the first case of using ESWL to remove encrusted foley catheter retained in the bladder.

Characterization and modification of cavitation pattern in shock wave lithotripsy

NARCIS (Netherlands)

Arora, M.; Ohl, C.D.; Liebler, Marko

2004-01-01

The temporal and spatial dynamics of cavitation bubble cloud growth and collapse in extracorporeal shock wave lithotripsy (ESWL) is studied experimentally. The first objective is obtaining reproducible cloud patterns experimentally and comparing them with FDTD-calculations. Second, we describe a

Extracorporeal shock wave lithotripsy in the treatment of renal and ureteral stones

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Fábio César Miranda Torricelli

2015-02-01

Full Text Available The use of certain technical principles and the selection of favorable cases can optimize the results of extracorporeal shock wave lithotripsy (ESWL. The aim of this study is to review how ESWL works, its indications and contraindications, predictive factors for success, and its complications. A search was conducted on the Pubmed® database between January 1984 and October 2013 using "shock wave lithotripsy" and "stone" as key-words. Only articles with a high level of evidence, in English, and conducted in humans, such as clinical trials or review/meta-analysis, were included. To optimize the search for the ESWL results, several technical factors including type of lithotripsy device, energy and frequency of pulses, coupling of the patient to the lithotriptor, location of the calculus, and type of anesthesia should be taken into consideration. Other factors related to the patient, stone size and density, skin to stone distance, anatomy of the excretory path, and kidney anomalies are also important. Antibiotic prophylaxis is not necessary, and routine double J stent placement before the procedure is not routinely recommended. Alpha-blockers, particularly tamsulosin, are useful for stones >10mm. Minor complications may occur following ESWL, which generally respond well to clinical interventions. The relationship between ESWL and hypertension/diabetes is not well established.

Renal pelvic stones: choosing shock wave lithotripsy or percutaneous nephrolithotomy

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Robert Marcovich

2003-06-01

Full Text Available Introduction of minimally invasive techniques has revolutionized the surgical management of renal calculi. Extracorporeal shock wave lithotripsy and percutaneous nephrolithotomy are now both well-established procedures. Each modality has advantages and disadvantages, and the application of each should be based on well-defined factors. These variables include stone factors such as number, size, and composition; factors related to the stone's environment, including the stone's location, spatial anatomy of the renal collecting system, presence of hydronephrosis, and other anatomic variables, such as the presence of calyceal diverticula and renal anomalies; and clinical or patient factors like morbid obesity, the presence of a solitary kidney, and renal insufficiency. The morbidity of each procedure in relation to its efficacy should be taken in to account. This article will review current knowledge and suggest an algorithm for the rational management of renal calculi with shock wave lithotripsy and percutaneous nephrolithotomy.

paediatric ureteric calculi: in-situ extracorporeal shock wave lithotripsy

African Journals Online (AJOL)

Objective To evaluate prospectively the efficacy of in-situ extracorporeal shock wave lithotripsy (ESWL) in the treatment of ureteric calculi in the paediatric age group. Patients and Methods Twenty children (aged 2.2 16 years) with 22 ureteric stones were evaluated and treated with in-situ ESWL using the Dornier S lithotripter ...

Design, Prototyping and Control of a Flexible Cystoscope for Biomedical Applications

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Sozer, Canberk; Ghorbani, Morteza; Alcan, Gokhan; Uvet, Huseyin; Unel, Mustafa; Kosar, Ali

2017-07-01

Kidney stone and prostate hyperplasia are very common urogenital diseases all over the world. To treat these diseases, one of the ESWL (Extracorporeal Shock Wave Lithotripsy), PCNL (Percutaneous Nephrolithotomy), cystoscopes or open surgery techniques can be used. Cystoscopes named devices are used for in-vivo intervention. A flexible or rigid cystoscope device is inserted into human body and operates on interested area. In this study, a flexible cystoscope prototype has been developed. The prototype is able to bend up to ±40°in X and Y axes, has a hydrodynamic cavitation probe for rounding sharp edges of kidney stone or resection of the filled prostate with hydrodynamic cavitation method and contains a waterproof medical camera to give visual feedback to the operator. The operator steers the flexible end-effector via joystick toward target region. This paper presents design, manufacturing, control and experimental setup of the tendon driven flexible cystoscope prototype. The prototype is 10 mm in outer diameter, 70 mm in flexible part only and 120 mm in total length with flexible part and rigid tube. The experimental results show that the prototype bending mechanism, control system, manufactured prototype parts and experimental setup function properly. A small piece of real kidney stone was broken in targeted area.

Pediatric extracorporeal shock wave lithotripsy: Predicting successful outcomes.

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McAdams, Sean; Shukla, Aseem R

2010-10-01

Extracorporeal shock wave lithotripsy (ESWL) is currently a first-line procedure of most upper urinary tract stones ionizing radiation, perhaps utilizing advancements in ultrasound and magnetic resonance imaging. This report provides a review of the current literature evaluating the patient attributes and stone factors that may be predictive of successful ESWL outcomes along with reviewing the role of pre-operative imaging and considerations for patient safety.

Which Flexible Ureteroscopes (Digital vs. Fiber-Optic) Can Easily Reach the Difficult Lower Pole Calices and Have Better End-Tip Deflection: In Vitro Study on K-Box. A PETRA Evaluation.

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Dragos, Laurian B; Somani, Bhaskar K; Sener, Emre T; Buttice, Salvatore; Proietti, Silvia; Ploumidis, Achilles; Iacoboaie, Catalin T; Doizi, Steeve; Traxer, Olivier

2017-07-01

Modern flexible ureteroscopes (fURSs) have good deflection, but despite this, approaching an acute angled calix can still be difficult. The goals of our in vitro study were to assess the ability of the available modern fURSs to effectively access the sharp angled calices and to compare the end-tip deflection of the various fiber-optic and digital fURSs. Using a bench-training model for FURS (K-Box, Porgès-Coloplast), we tried to access an acute angled calix with nine different fURSs (BOA vision, COBRA vision, R.Wolf; FLEX X 2 , FLEX Xc, K.Storz; LithoVue, Boston Scientific; URF-P5, URF-P6, URF-V, URF-V2, Olympus). Passing the fURSs through a ureteral access sheath (ReTrace, Porgès-Coloplast), the maximum end-tip deflection for every fURS was measured with the tip extended out from the sheath at 1, 2, 3, and 4 cm. Two ranking methods were designed for scoring the fURSs, one based on total ranking points and the other on total degrees of deflection. While all fiber-optic fURSs (except URF-P6) were able to access the sharp angled calix, none of the digital fURSs (except FLEX Xc) reached the difficult angled calix. Similarly, all fiber-optic fURSs had better end-tip deflection compared with the digital fURSs, except FLEX Xc, which was as deflectable as the fiber-optic fURSs. The fURSs showed an end-tip deflection (median difference of almost 21°) in favor of fiber-optic fURSs. Based on the scoring, the highest ranked fURS (best deflection) was FLEX X2 and the lowest ranked fURS (worst deflection) was URF-V2. Digital fURSs were less effective in accessing the sharp angled calix and they had lesser end-tip deflection compared with the fiber-optic counterparts. When approaching a difficult lower pole calix, it might be better to use a fiber-optic fURS.

Lung contusion and cavitation with exudative plural effusion following extracorporeal shock wave lithotripsy in an adult: a case report

Directory of Open Access Journals (Sweden)

Nouri-Majalan Nader

2010-08-01

Full Text Available Abstract Introduction Among the complications of extracorporeal shock wave lithotripsy are perinephric bleeding and hypertension. Case presentation We describe the case of a 31-year-old Asian man with an unusual case of hemoptysis and lung contusion and cavitation with exudative plural effusion due to pulmonary trauma following false positioning of extracorporeal shock wave lithotripsy. Differential diagnoses included pneumonia and pulmonary emboli, but these diagnoses were ruled out by the uniformly negative results of a lung perfusion scan, Doppler ultrasound, and culture of bronchoalveolar lavage and plural effusion, and because our patient showed spontaneous improvement. Conclusions False positioning of extracorporeal shock wave lithotripsy can cause lung trauma presenting as pulmonary contusion and cavitation with plural effusion.

Extracorporeal shock wave lithotripsy 25 years later: complications and their prevention

NARCIS (Netherlands)

Skolarikos, Andreas; Alivizatos, Gerasimos; de la Rosette, Jean

2006-01-01

OBJECTIVE: We review the pathophysiology and possible prevention measures of complications after extracorporeal shock wave lithotripsy (ESWL). METHODS: A literature search was performed with the Medline database on ESWL between 1980 and 2004. RESULTS: ESWL application has been intuitively connected

Peroral cholangioscopy with intracorporeal electrohydraulic lithotripsy for choledocholithiasis.

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Hixson, L J; Fennerty, M B; Jaffee, P E; Pulju, J H; Palley, S L

1992-03-01

Five patients with choledocholithiasis refractory to standard extraction methods after endoscopic sphincterotomy underwent peroral cholangioscopy with the "mother-daughter" endoscopy system. electrohydraulic lithotripsy of nine stones was performed successfully and without complication, other than minor transient bleeding in one patient. The outer sheath of the "daughter scope" sustained a linear burn in one instance. This method of stone fragmentation is a useful adjunct to achieve ductal clearance in difficult cases.

Kidney changes after extracorporeal shock wave lithotripsy

International Nuclear Information System (INIS)

Yoshioka, Hiroyasu; Shindo, Hiroshi; Mabuchi, Nobuhisa; Kawakami, Akira; Fujii, Koichi; Hamada, Tatsumi; Ishida, Osamu; Umekawa, Toru; Kohri, Kenjiro

1991-01-01

MRI was performed before and after extracorporeal shock wave lithotripsy (ESWL) to determine the effects of ESWL on the kidney and perinephric tissues. Of the 40 kidneys studied, 24 showed one or more changes on MRI: loss of the corticomedullary junction (n=15), subcapsular fluid (n=14), subcapsular hematoma (n=1), thickening of bridging septa (n=8), high intensity area in the muscle (n=8). These relatively subtle changes detected on MRI may not be apparent with other imaging techniques. (author)

Efficacy of commercialised extracorporeal shock wave lithotripsy service: a review of 589 renal stones.

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Nielsen, Tommy Kjærgaard; Jensen, Jørgen Bjerggaard

2017-07-27

Extracorporeal shockwave lithotripsy (ESWL) is the management of choice for renal stones 20 mm or smaller, with a stone clearance rate of up to 89%. The purpose of the present is to investigate the efficacy of a commercialised ESWL service, being performed as an outsourced treatment using a mobile lithotripsy system on an outpatient basis. Furthermore, the study aims to evaluate the risk of needing treatment with an internal ureteral double-J stent (JJ) after ESWL treatment. During an eight-year period, 461 patients with a total of 589 renal stones were treated using a mobile lithotripsy system at a single Danish institution. A commercial company performed all treatments using a Storz Modulith SLK® system. Each stone was prospectively registered according to size, intra renal location and the presence of a JJ at the time of treatment. The number of required ESWL treatments and auxiliary procedures were retrospectively evaluated. The success rate after the initial ESWL procedure was 69%, which increased to an overall success rate of 93% after repeated treatment. A negative correlation was found between stone size and the overall success rate (r = -0.2, p ESWL procedure. No significant difference was observed between the stone size or intra renal location and the risk of needing treatment with JJ after ESWL. Commercialised ESWL treatment can achieve an overall success rate of more than 90% using a mobile lithotripsy system. As expected, an inverse relation between stone size and success rate was found. Patients who do not require treatment with a JJ prior to ESWL will only rarely need treatment with a JJ after ESWL, irrespective of stone size and intra renal stone location.

[EFFECTIVENESS OF EXTRACORPOREAL SHOCK WAVE LITHOTRIPSY IN PATIENTS WITH UROLITHIASIS OF A SOLITARY KIDNEY].

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Parshenkova, I G; Dutov, V V; Rumjancev, A A; Mamedov, E A

2015-01-01

The article presents results of extracorporeal shock wave lithotripsy (ESWL) in 62 patients with urolithiasis of a solitary kidney. In 50 (80.6%) patients calculi were located in the kidney and in 12 (19.4%) patients in the ureter. Effectiveness of ESWL at 3 month follow-up was 85.5%, which is somewhat lower than in patients with two healthy kidneys due to the choice of sparing low-energy modes of lithotripsy. The effectiveness of ESWL depended on the size of the original calculi (ppre-drainage of the kidney before a session of ESWL in patients with large and multiple calculi. There was no correlation between the occurrence of complications during treatment and the clinical form of a solitary kidney (p>0.05). In patients with stones larger than 1 cm and a moderate baseline abnormalities of the upper urinary tract urodynamics ESWL was less effective (pcalculus (p=0.504). Extracorporeal shock wave lithotripsy is a highly effective and safe treatment of stones of a solitary kidney. Rational choice of indications and contraindications for the use of ESWL in a specific clinical situation is of great importance.

Multimodal treatment in difficult sialolithiasis: Role of extracorporeal shock-wave lithotripsy and intraductal pneumatic lithotripsy.

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Koch, Michael; Schapher, Mirco; Mantsopoulos, Konstantinos; von Scotti, Felix; Goncalves, Miguel; Iro, Heinrich

2017-12-15

To assess results after treatment of difficult/complex sialolithiasis with extracorporeal shock-wave lithotripsy (ESWL) and intraductal pneumatic lithotripsy (IPL). Retrospective study in a tertiary referral center. Altogether, 63 stones were diagnosed in 38 patients with difficult/complex sialolithiasis. Forty-nine stones were treated with fragmentation using both ESWL and IPL. Stones accessible with the sialendoscope were treated primarily with IPL in multiple sialolithiasis. Seventy-one ESWL procedures and 57 IPL were performed in our patients. Forty-nine stones were treated by 67 ESWL procedures and 52 IPL. ESWL converted sialoliths from sialendoscopically untreatable into sialendoscopically treatable cases in 94.7%; the treatment then was completed by a total of 52 IPL procedures. ESWL was performed before IPL (81.6%), in combination with IPL (7.9%) and after (10.5%). Complete fragmentation was achieved in 97.9%. Four stones each were treated with ESWL and IPL alone in multiple sialolithiasis. Altogether, 53 stones were treated by 57 IPL procedures. Complete fragmentation was achieved in 98.1% of the 53 stones. ESWL and IPL were the dominant treatment modalities in 84.1% of all 63 stones treated. Of all 38 patients, 92.1% became stone-free and all became symptom-free. All the glands were preserved. Multiple stones were treated in 34.2% of the patients; of these, 92.3% became stone-free. These results show that patients with difficult and complex sialolithiasis can be treated with high success rates of > 90% using a multimodal, minimally invasive, and gland-preserving treatment approach. ESWL and IPL played a key role in this multimodal treatment regime in > 80% of stones. 4. Laryngoscope, 2017. © 2017 The American Laryngological, Rhinological and Otological Society, Inc.

Laser in urology. Laser i urologien

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Breisland, H.O. (Aker Sykehus, Oslo (Norway))

1991-09-01

The neodymium YAG laser is particularly suited for endoscopic urologic surgery because the YAG laser light can be conducted in flexible fibers. Superficial bladder tumours can be treated under local anaesthesia in the outpatient department. The frequency of local recurrences is low, significantly lower than after electrosection or electrocoagulation. Selected cases of T2-muscle invasive bladder tumours can be cured with laser coagulation applied subsequently to transurethral resection. Combined treatment with electrosection and laser coagulation of localized prostatic cancer is a promising method which compares favourably with results obtained by other treatment modalities. Tumours in the upper urinary tract can be laser-treated through ureteroscopes or nephroscopes, but the treatment should be limited to low stage, low grade tumours. Laser is the treatment of choice for intraurethral condylomatas. Laser treatment of penil carcinoma gives excellent cosmetic and functional results and few local recurrences. Laser lithotripsy is a new technique for treatment of ureteric stones and photodynamic laser therapy is a promising tecnique for treatment of carcinoma in situ in the bladder empithelium. However, neither of these techniques are available for clinical use in Norway as yet. 17 refs., 3 figs., 1 tabs.

Laser in urology

International Nuclear Information System (INIS)

Breisland, H.O.

1991-01-01

The neodymium YAG laser is particularly suited for endoscopic urologic surgery because the YAG laser light can be conducted in flexible fibers. Superficial bladder tumours can be treated under local anaesthesia in the outpatient department. The frequency of local recurrences is low, significantly lower than after electrosection or electrocoagulation. Selected cases of T2-muscle invasive bladder tumours can be cured with laser coagulation applied subsequently to transurethral resection. Combined treatment with electrosection and laser coagulation of localized prostatic cancer is a promising method which compares favourably with results obtained by other treatment modalities. Tumours in the upper urinary tract can be laser-treated through ureteroscopes or nephroscopes, but the treatment should be limited to low stage, low grade tumours. Laser is the treatment of choice for intraurethral condylomatas. Laser treatment of penil carcinoma gives excellent cosmetic and functional results and few local recurrences. Laser lithotripsy is a new technique for treatment of ureteric stones and photodynamic laser therapy is a promising tecnique for treatment of carcinoma in situ in the bladder empithelium. However, neither of these techniques are available for clinical use in Norway as yet. 17 refs., 3 figs., 1 tabs

Role of extracorporeal shock wave lithotripsy in hepato-biliary-pancreatic surgery

NARCIS (Netherlands)

R.L. van der Hul (René); P.W. Plaisier; O.T. Terpstra (Onno); H.A. Bruining (Hajo)

1993-01-01

textabstractSince the early 1980s extracorporeal shock wave lithotripsy (ESWL) has partially replaced major operative procedures in various fields of surgery. In the interest of the patient, it is important to determine the exact role of ESWL in surgery. Comparing our own prospectively followed

PROSPECTIVE STUDY TO COMPARE THE EFFICACY OF ANALGESIC AGENTS USED FOR THE PAIN MANAGEMENT DURING EXTRACORPOREAL SHOCK WAVE LITHOTRIPSY

OpenAIRE

Abhirudra; Mehul; Sharada Kumar; Vilas; Vikram; Deepak; Sunil; Naveen

2016-01-01

BACKGROUND Extracorporeal shock wave lithotripsy (ESWL) is well known for its non-invasiveness, effectiveness and minimal morbidity for the management of renal stones. Some generation of lithotripters were associated with significant pain, needing anaesthesia. In modern lithotripters, pain is insignificant making lithotripsy an outpatient procedure (day care). AIMS The present study is aimed to compare the clinical efficacy between four drugs. METHODS AND MATERIALS This...

Efficacy of extracorporeal shockwave lithotripsy using Dornier SII in different levels of ureteral stones

Science.gov (United States)

Elkholy, Mohamed M.; Ismail, Hassan; Abdelkhalek, Mohamed A.; Badr, Mohamad M.; Elfeky, Mohamed M.

2014-01-01

Objective: The objective of this study was to evaluate the efficacy and safety of the Dornier lithotripter S II system in the treatment of ureteral calculi. Patients and Methods: A total of 97 cases which consists of 54 males and 43 females with ureteral stones were treated by extracorporeal shock wave lithotripsy (ESWL). Mean age was 42.6 years. Inclusion criteria were solitary radiopaque ureteral stones of radiological stone size of ≤1 cm. The stones were not impacted, with normal kidney functions. Procedure time, number of shocks, energy used, number of sessions and complications were reported. The outcome of ESWL was also recorded. Results: Stones were in the abdominal (upper ureter) in 50% of patients, in pelvic (middle ureter) in 47% of patients. All patients had unilateral stones and the mean stone size in maximum length was) 10 mm). Good dye excretion passing the stone was noted in all patients. Mild hydronephrosis was found in 85% of cases. A total of 49 cases were treated by a single session, while in 35% of cases two sessions were enough and 16% received three sessions. The average number of shocks per session was 3125. The average number of shocks per patient was 5962.5 shocks and average energy was 204.3 Joules. The overall stone-free rate 3 months after lithotripsy was 94%. After a single session of lithotripsy, 49 patients (49%) became stone-free. Stone free rates after ESWL for upper, middle ureteral stones were 94%, 95.7% respectively. Additional procedures were needed in only 6 cases (6%) to render patients stone-free after lithotripsy. No serious complications occurred. Conclusion: The Dornier lithotripter S II is very effective in the treatment of ureteral calculi with no major complications. PMID:25371614

Shock-wave lithotripsy of gallstones

International Nuclear Information System (INIS)

Torres, W.E.; Baumgartner, B.R.; Nelson, R.C.; Morris, S.J.

1990-01-01

This paper evaluates the American Dornier MPL-9000 gallstone study on the effectiveness and safety of biliary extracorporeal shock wave lithotripsy (ESWL) and, in a prospective double blind manner, the need for ursodeoxycholic acid (UDCA). At our institution, 174 symptomatic patients with gallstones (149 with noncalcified stones and 25 with calcified stones) were randomized to receive UDCA or placebo for 6 months. The gallstones were fragmented in 171/174 patients (98%). Evaluation by ultrasound was done at 6 weeks following ESWL; retreatment was done on 42/174 patients for fragments larger than 5 mm. Cholecystectomy was done in 6/174 patients. The 6- and 12- month stone-free rates were noncalcified stones + UDCA, 31% and 41%; noncalcified stones + placebo, 24% and 15%; calcified gallstones, 8% and 8%

Long-term effects of pediatric extracorporeal shockwave lithotripsy on renal function

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Akin Y

2014-04-01

Full Text Available Yigit Akin,1 Selcuk Yucel21Department of Urology, Harran University School of Medicine, Sanliurfa, Turkey; 2Department of Urology, Acibadem University School of Medicine, Istanbul, TurkeyIntroduction: Extracorporeal shock wave lithotripsy (ESWL is a well-known and successful treatment modality. In addition, it can be used in premature infants. ESWL is used to treat kidney and ureter stones in children. However, although it is a preferred noninvasive treatment in that setting, there is debate about its long-term effects on growing kidneys in children.Objectives: To investigate the long-term effects of pediatric ESWL on renal function in light of updated literature.Methods: PubMed and Medline were searched for studies on ESWL in a pediatric population with keywords including efficacy, child, kidney calculi, ureter calculi, lithotripsy, injury, vascular trauma, and shock waves. The research was limited to the English literature during a period from 1980 to 2014. In total, 3,000 articles were evaluated, but only 151 papers were considered. Only the manuscripts directly related to the reviewed subjects were included in the current study.Results: However, the acute effects of ESWL in kidney are well-described. Although there are limited studies on the long-term effects of ESWL in children, there is a widespread opinion that ESWL is not affecting renal functions in the long-term.Conclusion: ESWL is a safe, effective, and noninvasive treatment option in children. Although ESWL can cause some acute effects in the kidney, there is no long-term effect on the growing kidneys of children.Keywords: child, lithotripsy, nephrolithiasis, renal injury, vascular trauma

3D dynamic simulation of crack propagation in extracorporeal shock wave lithotripsy

Science.gov (United States)

Wijerathne, M. L. L.; Hori, Muneo; Sakaguchi, Hide; Oguni, Kenji

2010-06-01

Some experimental observations of Shock Wave Lithotripsy(SWL), which include 3D dynamic crack propagation, are simulated with the aim of reproducing fragmentation of kidney stones with SWL. Extracorporeal shock wave lithotripsy (ESWL) is the fragmentation of kidney stones by focusing an ultrasonic pressure pulse onto the stones. 3D models with fine discretization are used to accurately capture the high amplitude shear shock waves. For solving the resulting large scale dynamic crack propagation problem, PDS-FEM is used; it provides numerically efficient failure treatments. With a distributed memory parallel code of PDS-FEM, experimentally observed 3D photoelastic images of transient stress waves and crack patterns in cylindrical samples are successfully reproduced. The numerical crack patterns are in good agreement with the experimental ones, quantitatively. The results shows that the high amplitude shear waves induced in solid, by the lithotriptor generated shock wave, play a dominant role in stone fragmentation.

Liver fibrosis after extracorporeal shock-wave lithotripsy of gallbladder stones - A case report

NARCIS (Netherlands)

P.W. Plaisier; J.F. Hamming (Jaap); R.L. van der Hul (René); R. den Toom (Rene); H.A. Bruining (Hajo)

1994-01-01

textabstractWe encountered significant liver fibrosis in a healthy young patient undergoing laparoscopic cholecystectomy for symptomatic gallstone disease. Twelve months prior to cholecystectomy the patient underwent multiple extracorporeal shock-wave lithotripsy (ESWL) sessions with adjuvant oral

High frequency jet ventilation through a supraglottic airway device: a case series of patients undergoing extra-corporeal shock wave lithotripsy.

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Canty, D J; Dhara, S S

2009-12-01

High frequency jet ventilation has been shown to be beneficial during extra-corporeal shock wave lithotripsy as it reduces urinary calculus movement which increases lithotripsy efficiency with better utilisation of shockwave energy and less patient exposure to tissue trauma. In all reports, sub-glottic high frequency jet ventilation was delivered through a tracheal tube or a jet catheter requiring paralysis and direct laryngoscopy. In this study, a simple method using supraglottic jet ventilation through a laryngeal mask attached to a circle absorber anaesthetic breathing system is described. The technique avoids the need for dense neuromuscular blockade for laryngoscopy and the potential complications associated with sub-glottic instrumentation and sub-glottic jet ventilation. The technique was successfully employed in a series of patients undergoing lithotripsy under general anaesthesia as an outpatient procedure.

Is Tamsulosin Effective after Shock Wave Lithotripsy for Pediatric Renal Stones? A Randomized, Controlled Study.

Science.gov (United States)

Shahat, Ahmed; Elderwy, Ahmad; Safwat, Ahmed S; Abdelkawi, Islam F; Reda, Ahmed; Abdelsalam, Yasser; Sayed, Mohamed; Hammouda, Hisham

2016-04-01

We assessed the effect of tamsulosin as an adjunctive therapy after shock wave lithotripsy for pediatric single renal pelvic stones. A total of 120 children with a unilateral single renal pelvic stone were included in a prospective randomized, controlled study. All children were randomized to 2 equal groups. Group 1 received tamsulosin (0.01 mg/kg once daily) as adjunctive therapy after shock wave lithotripsy in addition to paracetamol while group 2 received paracetamol only. Stone clearance was defined as no renal stone fragments or fragments less than 3 mm and no pelvicalyceal system dilatation. Our study included 69 boys and 51 girls with a median age of 3.5 years and a median stone size of 1.2 cm. There was no statistically significant difference between groups 1 and 2 in stone or patient criteria. Of the children 99 (82.5%) achieved stone clearance after the first session, including 50 in group 1 and 49 in group 2. All children in each group were cleared of stones after the second session. The overall complication rate was 14.2%. There was no statistically significant difference between single session stone clearance rates (p = 0.81) and complications rates (p = 0.432) in either group. On multivariate analysis using logistic regression smaller stone size (p = 0.016) and radiopaque stones (p = 0.019) were the only predictors of stone clearance at a single shock wave lithotripsy session. Tamsulosin therapy did not affect stone clearance (p = 0.649). Tamsulosin does not seem to improve renal stone clearance. Smaller and radiopaque renal stones have more chance of clearance after shock wave lithotripsy for pediatric single renal pelvic stones. Copyright © 2016 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Refinement of exclusionary criteria for lithotripsy

International Nuclear Information System (INIS)

Trefeiner, E.; Burrell, M.; McCarthy, S.; Rosenfield, A.

1989-01-01

This paper reports gallstones from 200 cholecystectomy patients examined with CT, US, and MR imaging. On CT scans, stones of over 50 HU had a mean bilirubinate content of 23%, versus 6.2% in those less than 50 HU. Forty-four percent of stones had MR signal on both T1- and T2-weighted images. When compared with stones without signal, these also has significantly higher CT numbers. Chemical shift imaging identified the signal as water protons. Therefore, stones above 50 HU are probably poor candidates for lithotripsy because of the increased concentrations of calcium bilirubinate and carbonate. The associated increased incidence of MR signal may be attributed to layers of water associated with bilirubinate salts

EFFECTIVENESS AND SAFETY OF EXTRACORPOREAL SHOCKWAVE LITHOTRIPSY FOR UNCOMPLICATED PELVIC CONCREMENTS

Directory of Open Access Journals (Sweden)

A. V. Khasigov

2017-01-01

Full Text Available Introduction. Extracorporeal shockwave lithotripsy (ESWL allowed to improve the treatment results for patients suffering from the kidney stone disease (KSD, decrease the number of complications, optimize the nearest and distant therapy results; however, its success depends on the initial size and shape of the stone. Purpose of the study. Тo examine the clinical effectiveness and safety of electromagnetic ESWL used on simple renal calculi taking their sizes into account. Materials and methods. The survey included 110 patients with simple renal calculi who passed electromagnetic ESWL procedures. The first group consisted of 75 patients with calculi ≤ 15 mm in diameter, the second group included 35 patients with stones > 15 mm. Results. Complete disintegration of stones ≤ 15 mm was accomplished in 74,7% of cases in 1-2 lithotripsy sessions, and after 3 months residual fragments were found in 4% of cases only. Elimination of stones > 15 mm from the renal collecting system takes considerably longer, all patients require more than 1 lithotripsy session. In 3 months following the ESWL residual stones were found in 17,2% of analysed cases. Stone sizes had no bearing on the pain syndrome frequency and severity as well as activation of urinary infection. Macrohematuria, renal haematomas, and an increase of blood creatinine level compared with the original value were more frequent in patients with stones > 15 mm. Conclusions. Electromagnetic ESWL is an efficient and safe method for monotherapy of patients with uncomplicated pelvic concrements. Clinical ESWL effectiveness for stones ≤15 mm by the 3rd month of monitoring reaches 96,0%, for stones > 15 mm it is 82,8% (р<0,05. The level and severity of complications is higher in case of pelvic stones >15 mm compared with the stones < 15 mm in diameter (р<0,05.

Diagnostic imaging for preparation of extracorporeal shockwave lithotripsy of gallbladder stones

International Nuclear Information System (INIS)

Brandstetter, K.; Golder, W.; Neuhaus, H.

1991-01-01

Extracorporeal shockwave lithotripsy can be applied as a non-invasive treatment of patients with predominantly cholesterol-type gallstones. As for this treatment, gall bladder contractility and patency of the ductus cysticus must be guaranteed, CT and sonography are applied to check these conditions, and also to determine the size and number of gallstones. (DG) [de

Effects of extracorporeal shock wave lithotripsy on the kidney and perinephric tissues: CT evaluation

Energy Technology Data Exchange (ETDEWEB)

Song, Kounn Sik; Kim, Kun Sang; Kim, Sae Chul [College of Medicine, Chung-Ang University, Seoul (Korea, Republic of)

1987-12-15

Since the first successful treatment of the patient with renal stone by extracorporeal shock wave lithotripsy at the Institute for Surgical Research, West Germany, on February 7, 1980, extracorporeal shock wave lithotripsy (ESWL) has been a non-invasive technique for the treatment of the renal and ureteral calculi. In spite of the fact that the acoustic energy of the focused shock waves must pass through the soft tissues of back, perinephric tissues and renal parenchyme before reaching calculi, little is known about the effects of ESWL in the renal parenchyme and perinephric soft tissues. So we analyzed a pre and post-ESWL computed tomography scans of the kidneys in 130 patients treated at our hospital during a three month period to evaluate the effects of ESWL on the kidney and perinephric soft tissues.

Effects of extracorporeal shock wave lithotripsy on the kidney and perinephric tissues: CT evaluation

International Nuclear Information System (INIS)

Song, Kounn Sik; Kim, Kun Sang; Kim, Sae Chul

1987-01-01

Since the first successful treatment of the patient with renal stone by extracorporeal shock wave lithotripsy at the Institute for Surgical Research, West Germany, on February 7, 1980, extracorporeal shock wave lithotripsy (ESWL) has been a non-invasive technique for the treatment of the renal and ureteral calculi. In spite of the fact that the acoustic energy of the focused shock waves must pass through the soft tissues of back, perinephric tissues and renal parenchyme before reaching calculi, little is known about the effects of ESWL in the renal parenchyme and perinephric soft tissues. So we analyzed a pre and post-ESWL computed tomography scans of the kidneys in 130 patients treated at our hospital during a three month period to evaluate the effects of ESWL on the kidney and perinephric soft tissues

Bacterial sepsis after extracorporeal shock-wave lithotripsy (ESWL) of calyceal diverticular stone.

Science.gov (United States)

Oh, Mi Mi; Kim, Jin Wook; Kim, Jong Wook; Chae, Ji Yun; Yoon, Cheol Yong; Park, Hong Seok; Park, Min Gu; Moon, Du Geon

2013-02-01

Most calyceal diverticula are asymptomatic but symptoms occur when there is urinary stasis leading to infection and calculi. Septic shock after ESWL of calyceal stone occurs rarely. A 24-year-old woman had septic shock due to after extracorporeal shock-wave lithotripsy (ESWL) of asymptomatic calyceal diverticular stone.

Kidney changes after extracorporeal shock wave lithotripsy; MR evaluation

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Yoshioka, Hiroyasu; Shindo, Hiroshi; Mabuchi, Nobuhisa; Kawakami, Akira; Fujii, Koichi; Hamada, Tatsumi; Ishida, Osamu; Umekawa, Toru; Kohri, Kenjiro (Kinki Univ., Osakasayama, Osaka (Japan). School of Medicine)

1991-02-01

MRI was performed before and after extracorporeal shock wave lithotripsy (ESWL) to determine the effects of ESWL on the kidney and perinephric tissues. Of the 40 kidneys studied, 24 showed one or more changes on MRI: loss of the corticomedullary junction (n=15), subcapsular fluid (n=14), subcapsular hematoma (n=1), thickening of bridging septa (n=8), high intensity area in the muscle (n=8). These relatively subtle changes detected on MRI may not be apparent with other imaging techniques. (author).

Emergency extracorporeal shock wave lithotripsy (ESWL) for obstructing ureteral stones.

Science.gov (United States)

Tligui, M; El Khadime, M R; Tchala, K; Haab, F; Traxer, O; Gattegno, B; Thibault, P

2003-05-01

To evaluate emergency treatment of obstructing ureteral stones by in situ extracorporeal shock wave lithotripsy (ESWL) during acute renal colic. From January 1994 to February 2000, 200 patients (mean age: 42 years) were treated by ESWL (EDAP LT-02) for obstructing ureteral stones causing acute renal colic refractory to medical treatment or recurring within 24hours of such treatment. Stones were visualised by fluoroscopic imaging and/or ultrasound. Follow-up included radiological and/or ultrasound examinations and lasted three months. Mean stone size was 7mm (3-20mm). At three months, 164/200 (82%) patients were stone-free. This rate ranged from 79% to 83% according to the location of the stone, and from 75% to 86% according to the size of the stone. These differences in rate were not significant. Two or three ESWL sessions were required in 79 patients. ESWL was well tolerated in 90% of patients. The only complication was a case of pyelonephritis requiring the placement of a JJ stent, administration of antibiotics, and distant ureteroscopy. The 36 patients, in whom ESWL failed, underwent ureteroscopy (n=23) or lithotripsy with a Dornier machine (n=13). Non-deferred ESWL for acute renal colic secondary to obstructing ureteral stones has a satisfactory success rate and very low morbidity.

Comparison of safety and outcomes of shock wave lithotripsy between elderly and non-elderly patients

Directory of Open Access Journals (Sweden)

Chen YZ

2017-04-01

Full Text Available Yi-Zhong Chen,1 Wun-Rong Lin,1,2 Chih-Chiao Lee,1,2 Fang-Ju Sun,1,3 Yung-Chiong Chow,1,2 Wei-Kung Tsai,1,2 Pai-Kai Chiang,1,2 Ting-Po Lin,1,2 Marcelo Chen,1–3 Allen W Chiu1,4 1Department of Urology, MacKay Memorial Hospital, 2School of Medicine, MacKay Medical College, 3Department of Cosmetic Applications and Management, MacKay Junior College of Medicine, Nursing and Management, 4School of Medicine, National Yang-Ming University, Taipei, Taiwan Background: This study compared the clinical outcomes of extracorporeal shock wave lithotripsy between elderly (aged ≥65 years and non-elderly (aged <65 years patients.Methods: A retrospective review of medical records was performed on 483 (non-elderly: 245, elderly: 238 patients with upper urinary tract stones who underwent shock wave lithotripsy between 2007 and 2015. The demographic data, stone parameters, stone-free rate, retreatment rate, and complication rate were analyzed in both elderly and non-elderly patient groups.Results: There was no significant difference between non-elderly and elderly patients in terms of stone-free rate (46.5% vs 41.1%, P>0.05 regardless of stone site or stone size and overall retreatment rate (41.6% vs 37.0%, P>0.05. Elderly patients had a higher complication rate than non-elderly patients (15.5% vs 23.5%, P=0.026. The most common complication was flank pain. Receiver operating characteristic curves predicted that elderly patients (cutoff value: 65 years of age had a higher risk of complications and that patients with smaller stones (cutoff value: 0.8 cm had a higher stone-free rate.Conclusion: This study showed that elderly patients with upper urinary tract stones undergoing shock wave lithotripsy had comparable efficacy for stone-free rates and retreatment rates, but higher complication rates. Keywords: elderly, shock wave lithotripsy, upper urinary tract stone, safety, outcome

CT findings complicating percutaneous nephrostomy, lithotomy and lithotripsy

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Kanazawa, Susumu; Douke, Tetsuya; Araki, Toru; Takamoto, Hitoshi; Yoshida, Mitsuhiro; Hata, Kazuhiro (Center for Adult Diseases, Kurashiki, Okayama (Japan)); Yasui, Kotaro

1990-09-01

Reviews of the CT scans of percutaneous nephrostomy, lithotomy and lithotripsy disclosed 14 out of 78 cases (17.9%) with evidence of complications. Renal and perirenal hematomas were detected in five cases and the other five cases showed collections of contrast material in the retroperitoneum except for the anterior pararenal space. CT demonstrated clearly the anatomic distribution and extent of renal hemorrhage and extravasation of contrast material. Three cases of pleural effusion on CT were accompanied by blood or contrast material collections in the posterior pararenal space. No patients required immediate surgery and CT findings helped the choice of conservative therapies. (author).

Acoustic wave focusing in an ellipsoidal reflector for extracorporeal shock-wave lithotripsy

Science.gov (United States)

Lottati, Itzhak; Eidelman, Shmuel

1993-07-01

Simulations of acoustic wave focusing in an ellipsoidal reflector for extracorporeal shock-wave lithotripsy (ESWL) are presented. The simulations are done on a structured/unstructured grid with a modified Tait equation of state for water. The Euler equations are solved by applying a second-order Godunov method. The computed results compare very well with the experimental results.

Endoscopic-assisted electrohydraulic shockwave lithotripsy in standing sedated horses.

Science.gov (United States)

Röcken, Michael; Fürst, Anton; Kummer, Martin; Mosel, Gesine; Tschanz, Theo; Lischer, Christoph J

2012-07-01

To report use of transendoscopic electrohydraulic shockwave lithotripsy for fragmentation of urinary calculi in horses. Case series. Male horses (n = 21). Fragmentation of cystic calculi (median, 6 cm diameter; range, 4-11 cm diameter) was achieved by transurethral endoscopy in standing sedated horses using an electrohydraulic shockwave fiber introduced through the biopsy channel of an endoscope. The fiber was advanced until it contacted the calculus. Repeated activation of the fiber was used to disrupt the calculus into fragments calculus removal was achieved in 20 horses (95%) with mean total surgical time of 168.6 minutes (range, 45-450). In the 20 horses with single calculi, 1-6 sessions were required to completely fragment the calculus. Except for 1 horse, in which perineal urethrotomy was eventually performed for complete fragment removal, fragments calculi were excreted via the urethra. Postoperative complications included hematuria because of severe mucosal erosion (n = 2), dysuria because of a trapped urethral fragment (2), small amount of urinary debris (1). One horse was euthanatized because of bladder rupture. Complete clearance of calculi and urinary debris was confirmed endoscopically 20 (3-45) days after the last session. Telephone follow-up (mean, 18.8 months; range, 7-24 months) revealed that horses had returned to previous activity levels without recurrence of clinical signs. Transendoscopic electrohydraulic lithotripsy appears to be an effective method for fragmentation of low-density calcium carbonate cystic calculi in male horses. Copyright 2012 by The American College of Veterinary Surgeons.

A passive acoustic monitor of treatment effectiveness during extracorporeal lithotripsy

Science.gov (United States)

Fedele, F.; Thomas, K.; Leighton, T. G.; Ryves, S.; Phillips, D.; Coleman, A. J.

2011-02-01

Although extracorporeal shockwave lithotripsy (ESWL) has now been in the clinic for at least three decades, there has been little advance in efforts (i) to estimate the efficacy of the treatment whilst it is in progress, or (ii) to determine the end-point of a treatment session in terms of the degree of stone fragmentation achieved. Previous in vitro experimentation and clinical trials have shown that a passive acoustic monitor has the potential to provide evidence of the effectiveness and end-point of lithotripsy. The system exploits secondary emissions generated during shock-tissue interaction, whose features depend on the quality of tissue at the beam focus. This prototype was developed into the first commercially available clinical ESWL treatment monitor (Precision Acoustic Ltd, Dorchester, UK), and a unit has been acquired and tested in the clinical routine by urologists at Guy's and St Thomas NHS Trust in March 2009. This paper critically assesses the performance of the new system for the first 25 treatments monitored. The ESWL monitor correctly predicted the treatment outcome of 15 of the 18 treatments that were followed-up clinically. In addition, it was noted that the measure of treatment effectiveness provided by the monitor after 500 shocks was predictive of the final treatment outcome (p ESWL or if the patient should be sent for surgery.

Extracorporeal Shock-wave Lithotripsy Success Rate and Complications: Initial Experience at Sultan Qaboos University Hospital

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Mohammed S. Al-Marhoon

2013-07-01

Full Text Available Objective: To assess the efficacy and safety of extracorporeal shock wave lithotripsy with Modularis Vario Siemens in the management of patients with renal and ureteral stones.Methods: Between 2007 and 2009, 225 outpatients were treated with Siemens Modularis Vario lithotripter at Sultan Qaboos University Hospital. Stone size, location, total number of shockwaves, stone-free rate, complications and adjunctive interventions were investigated. Chi-Square and Logistic Regression analyses were used, with p<0.05 set as the level of significance.Results: Of the 225 initial consecutive patients who underwent extracorporeal shock wave lithotripsy, 192 (85% had renal stones and 33 (15% had ureteric stones. The mean±SD stone size was 11.3 ± 4.5 mm, while the mean age of the patients was 39.9 ± 12.8 years with 68.5% males. The mean renal stone size was 11.6 ± 4.7 mm; a mean of 1.3 sessions was required. The mean ureteric stone size was 9.9 ± 3 mm; and a mean of 1.3 sessions was required. Treatment success (defined as complete clearance of ureteric stones, stone-free or clinically insignificant residual fragments of <4 mm for renal stones was 74% for renal stones and 88% for ureteric stones. Additional extracorporeal shock wave lithotripsy and ureteroscopy were the most adjunctive procedures used for stone clearance. Complications occurred in 74 patients (38.5% with renal stones and 13 patients (39.4% with uretetric stones. The most common complication was loin pain (experienced by 16.7% with renal stones and 21% with ureteric stones. Severe renal colic mandating admission occurred in 2% of patients with renal stones and 6% of patients with ureteric stones. In patients with renal stone, steinstrasse occurred in 3.6% and infection post extracorporeal shock wave lithotripsy in 0.5%. Using Multivariate Logistic Regression analysis, factors found to have significant effect on complete stone clearance were serum creatinine (p=0.004 and the number of

Symptomatic gallbladder stones. Cost-effectiveness of treatment with extracorporeal shock-wave lithotripsy, conventional and laparoscopic cholecystectomy

NARCIS (Netherlands)

Go, P. M.; Stolk, M. F.; Obertop, H.; Dirksen, C.; van der Elst, D. H.; Ament, A.; van Erpecum, K. J.; van Berge Henegouwen, G. P.; Gouma, D. J.

1995-01-01

In order to strike the most favorable balance between health benefits and costs, three treatment modalities for symptomatic cholelithiasis were compared in a cost-effectiveness study: extracorporeal shock-wave lithotripsy (ESWL), conventional cholecystectomy (CC), and laparoscopic cholecystectomy

Can infundibular height predict the clearance of lower pole calyceal stone after extracorporeal shockwave lithotripsy?

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M. Arzoz-Fabregas

2009-04-01

Full Text Available PURPOSE: To evaluate the efficacy of extracorporeal shock wave lithotripsy (SWL on lower calyceal calculi in relation to the renal anatomical factors and determine which of these factors can be used to select patients who will benefit from SWL. MATERIAL AND METHODS: We analyzed retrospectively 78 patients with single radiopaque lower calyceal stones treated with SWL. The patients were evaluated 3 months after lithotripsy with a simple abdominal X-ray and a kidney ultrasound scan. The success of the treatment, removal of all fragments, was correlated with renal anatomical factors measured in the pre-treatment intravenous urography: infundibulopelvic angle, lower infundibulum width, lower infundibulum length, ratio length/width, infundibulum height, and number of minor calyces in the lower calyceal group. RESULTS: Three months after SWL treatment, 39 patients were stone-free (NR group and 39 had residual fragments (R group. Both groups presented no differences in relation to infundibulopelvic angle, width and length of the lower calyceal infundibulum, length/width ratio of the lower infundibulum or number of lower calyces. Height of the infundibulum, described as the distance between the line passing through the lowest part of the calyx containing the calculus and the highest point of the lower lip of renal pelvis, was the only parameter in which significant differences (p = 0.002 were found between the NR and R groups. CONCLUSIONS: Lower Infundibular height could be a good measurement tool for deciding which patients with lower calyceal lithiasis would benefit from SWL treatment. Height of less than 22 mm suggests a good outcome from lithotripsy.

Meta-analysis of Optimal Management of Lower Pole Stone of 10 - 20 mm: Flexible Ureteroscopy (FURS) versus Extracorporeal Shock Wave Lithotripsy (ESWL) versus Percutaneus Nephrolithotomy (PCNL).

Science.gov (United States)

Yuri, Prahara; Hariwibowo, Rinto; Soeroharjo, Indrawarman; Danarto, Raden; Hendri, Ahmad Z; Brodjonegoro, Sakti R; Rasyid, Nur; Birowo, Ponco; Widyahening, Indah S

2018-01-01

the optimal management of lower calyceal stones is still controversial, because no single method is suitable for the removal of all lower calyceal stones. Minimally invasive procedures such as extracorporeal shock wave lithotripsy (ESWL), percutaneous nephrolithotomy (PCNL) and flexible ureteroscopy (fURS) are the therapeutic methods for lower calyceal stones. The aim of this study was to identify the optimal management of 10-20 mm lower pole stones. a meta-analysis of cohort studies published before July 2016 was performed from Medline and Cochrane databases. Management of 10-20 mm lower pole stone treated by fURS, ESWL and PCNL with follow-up of residual stones in 1-3 months after procedure were include and urinary stone in other location and size were excluded. A fixed-effects model with Mantzel-Haenzel method was used to calculate the pooled Risk Ratio (RRs) and 95% Confidence Interval (CIs). We assessed the heterogeneity by calculating the I2 statistic. All analyses were performed with Review manager 5.3. we analized 8 cohort studies. The stone free rate from 958 patients (271 PCNL, 174 fURS and 513 ESWL), 3 months after operation, was 90.8% (246/271) after PCNL; 75.3% (131/174) after fURS; and 64.7% (332/513) after ESWL. Base on stone free rate in 10-20 mm lower pole stone following management, PCNL is better than fURS (overall RR was 1.32 (95% CI 1.13 - 1.55); pESWL (overall risk ratio 1.42 (95% CI 1.30 - 1.55); p=ESWL, fURS is better than ESWL base on stone free rate in 10-20 mm lower pole stone management with overall RR 1.16 (95% CI 1.04 - 1.30; p=0.01 and I2=40%). percutaneus nephrolithotomy provided a higher stone free rate than fURS and ESWL. This meta-analysis may help urologist in making decision of intervention in 10-20 mm lower pole stone management.

Radiation exposure to patients during extracorporeal shock wave lithotripsy

International Nuclear Information System (INIS)

Marti, J.M.; Robles, J.E.; Arbizu, J.; Castro, F. de; Berian, J.M.; Richter, J.A.

1992-01-01

We analyzed the radiological exposure to patients during Extracorporeal Shock Wave Lithotripsy (ESWL) using a second generator lithotriptor. Stone location is accomplished by fluoroscopy and 'quick pics' or snapshots. A prospective study over 55 patients showed a mean exposure of 32.2 R. The introduction of the ALARA criterion reduced it to 16.1 R in the following 145 patients. Mean radiation exposure to patient varies according to treatment difficulty. A mean increase of radiation exposure of 1.6 between low and high difficulty treatment groups was observed. This variation was about 96% when the physician who performed the treatment was considered. (author)

The efficacy of extracorporeal shock wave lithotripsy on single dense calcified gallstones according to computed tomography

Energy Technology Data Exchange (ETDEWEB)

Mori, Takao (Mie Univ., Tsu (Japan). School of Medicine); Shimono, Kazuko; Moriyama, Shigeru; Masuda, Touru; Ikeda, Tetsuya; Umegae, Satoru; Nagata, Norikazu

1993-05-01

The efficacy and complications of extracorporeal shock wave lithotripsy (ESWL) for single gallstones were compared between 15 patients with a CT-lucent stone and 18 patients with a dense calcified stone. In all of five patients with a stone smaller than 10 mm in diameter, complete or sufficient clearance was observed, regardless of calcification. However, in 28 patients with a stone larger than 11 mm in diameter, the rates of complete or sufficient clearance were lower in those with a dense calcified stone (64%) than in those with a computed tomography (CT) lucent stone (93%). There was no difference in the rate of complications between patients with a CT-lucent stone and those with a dense calcified stone. These results thus suggest that extracorporeal shock wave lithotripsy may be safely employed for patients with a single calcified gallstone. (author).

A passive acoustic monitor of treatment effectiveness during extracorporeal lithotripsy

International Nuclear Information System (INIS)

Fedele, F; Coleman, A J; Thomas, K; Ryves, S; Phillips, D; Leighton, T G

2011-01-01

Although extracorporeal shockwave lithotripsy (ESWL) has now been in the clinic for at least three decades, there has been little advance in efforts (i) to estimate the efficacy of the treatment whilst it is in progress, or (ii) to determine the end-point of a treatment session in terms of the degree of stone fragmentation achieved. Previous in vitro experimentation and clinical trials have shown that a passive acoustic monitor has the potential to provide evidence of the effectiveness and end-point of lithotripsy. The system exploits secondary emissions generated during shock-tissue interaction, whose features depend on the quality of tissue at the beam focus. This prototype was developed into the first commercially available clinical ESWL treatment monitor (Precision Acoustic Ltd, Dorchester, UK), and a unit has been acquired and tested in the clinical routine by urologists at Guy's and St Thomas NHS Trust in March 2009. This paper critically assesses the performance of the new system for the first 25 treatments monitored. The ESWL monitor correctly predicted the treatment outcome of 15 of the 18 treatments that were followed-up clinically. In addition, it was noted that the measure of treatment effectiveness provided by the monitor after 500 shocks was predictive of the final treatment outcome (p < 0.001). This suggests that the system could be used in pre-assessment; indicating if the stone is susceptible to ESWL or if the patient should be sent for surgery.

A passive acoustic monitor of treatment effectiveness during extracorporeal lithotripsy

Energy Technology Data Exchange (ETDEWEB)

Fedele, F; Coleman, A J [Medical Physics Department, Guy' s and St Thomas NHS Foundation Trust, Westminster Bridge Road, SE1 7EH, London (United Kingdom); Thomas, K; Ryves, S; Phillips, D [Urology Department, Guy' s and St Thomas NHS Foundation Trust, Great Maze Pond, SE1 9RT, London (United Kingdom); Leighton, T G, E-mail: fiammetta.fedele@gstt.nhs.uk [Institute of Sound and Vibration Research, University of Southampton, Highfield, S017 1BJ, Southampton (United Kingdom)

2011-02-01

Although extracorporeal shockwave lithotripsy (ESWL) has now been in the clinic for at least three decades, there has been little advance in efforts (i) to estimate the efficacy of the treatment whilst it is in progress, or (ii) to determine the end-point of a treatment session in terms of the degree of stone fragmentation achieved. Previous in vitro experimentation and clinical trials have shown that a passive acoustic monitor has the potential to provide evidence of the effectiveness and end-point of lithotripsy. The system exploits secondary emissions generated during shock-tissue interaction, whose features depend on the quality of tissue at the beam focus. This prototype was developed into the first commercially available clinical ESWL treatment monitor (Precision Acoustic Ltd, Dorchester, UK), and a unit has been acquired and tested in the clinical routine by urologists at Guy's and St Thomas NHS Trust in March 2009. This paper critically assesses the performance of the new system for the first 25 treatments monitored. The ESWL monitor correctly predicted the treatment outcome of 15 of the 18 treatments that were followed-up clinically. In addition, it was noted that the measure of treatment effectiveness provided by the monitor after 500 shocks was predictive of the final treatment outcome (p < 0.001). This suggests that the system could be used in pre-assessment; indicating if the stone is susceptible to ESWL or if the patient should be sent for surgery.

A passive acoustic monitor of treatment effectiveness during extracorporeal lithotripsy

Energy Technology Data Exchange (ETDEWEB)

Fedele, F; Coleman, A J [Medical Physics Department, Guy' s and St Thomas NHS Foundation Trust, Westminster Bridge Road, SE1 7EH, London (United Kingdom); Thomas, K; Ryves, S; Phillips, D [Urology Department, Guy' s and St Thomas NHS Foundation Trust, Great Maze Pond, SE1 9RT, London (United Kingdom); Leighton, T G, E-mail: fiammetta.fedele@gstt.nhs.uk [Institute of Sound and Vibration Research, University of Southampton, Highfield, S017 1BJ, Southampton (United Kingdom)

2011-02-01

Although extracorporeal shockwave lithotripsy (ESWL) has now been in the clinic for at least three decades, there has been little advance in efforts (i) to estimate the efficacy of the treatment whilst it is in progress, or (ii) to determine the end-point of a treatment session in terms of the degree of stone fragmentation achieved. Previous in vitro experimentation and clinical trials have shown that a passive acoustic monitor has the potential to provide evidence of the effectiveness and end-point of lithotripsy. The system exploits secondary emissions generated during shock-tissue interaction, whose features depend on the quality of tissue at the beam focus. This prototype was developed into the first commercially available clinical ESWL treatment monitor (Precision Acoustic Ltd, Dorchester, UK), and a unit has been acquired and tested in the clinical routine by urologists at Guy's and St Thomas NHS Trust in March 2009. This paper critically assesses the performance of the new system for the first 25 treatments monitored. The ESWL monitor correctly predicted the treatment outcome of 15 of the 18 treatments that were followed-up clinically. In addition, it was noted that the measure of treatment effectiveness provided by the monitor after 500 shocks was predictive of the final treatment outcome (p < 0.001). This suggests that the system could be used in pre-assessment; indicating if the stone is susceptible to ESWL or if the patient should be sent for surgery.

Perspective on Lithotripsy Adverse Effects

Science.gov (United States)

Knoll, Thomas; Wendt-Nordahl, Gunnar

2008-09-01

Shock wave lithotripsy (SWL) is an effective and without any doubt the least invasive procedure to treat upper urinary tract calculi. Acute complications are rarely reported and do not require specific treatment in most cases. However, one should be aware that energy levels sufficient for stone breakage are capable of damaging tissue as well, and significant hematoma—not only in the kidney but as well in surrounding organs—has been observed. Furthermore, only little is known about the long-term effects of SWL. Some authors have reported an increased incidence of hypertension and possibly also diabetes mellitus. Such chronic diseases—if indeed related to prior SWL—may be a late result of acute SWL-related trauma but the discussion on the underlying pathogenesis is controversial. Many factors have to be considered, such as the natural history of recurrent stone formers, technical principles of SWL, and differences in treatment protocols. Promising studies are currently underway to optimize stone breakage while limiting potential collateral damage. With this progress, SWL remains a safe treatment option for most urinary calculi.

Long-term effects of pediatric extracorporeal shockwave lithotripsy on renal function

Science.gov (United States)

Akin, Yigit; Yucel, Selcuk

2014-01-01

Introduction Extracorporeal shock wave lithotripsy (ESWL) is a well-known and successful treatment modality. In addition, it can be used in premature infants. ESWL is used to treat kidney and ureter stones in children. However, although it is a preferred noninvasive treatment in that setting, there is debate about its long-term effects on growing kidneys in children. Objectives To investigate the long-term effects of pediatric ESWL on renal function in light of updated literature. Methods PubMed and Medline were searched for studies on ESWL in a pediatric population with keywords including efficacy, child, kidney calculi, ureter calculi, lithotripsy, injury, vascular trauma, and shock waves. The research was limited to the English literature during a period from 1980 to 2014. In total, 3,000 articles were evaluated, but only 151 papers were considered. Only the manuscripts directly related to the reviewed subjects were included in the current study. Results However, the acute effects of ESWL in kidney are well-described. Although there are limited studies on the long-term effects of ESWL in children, there is a widespread opinion that ESWL is not affecting renal functions in the long-term. Conclusion ESWL is a safe, effective, and noninvasive treatment option in children. Although ESWL can cause some acute effects in the kidney, there is no long-term effect on the growing kidneys of children. PMID:24892029

Modeling elastic wave propagation in kidney stones with application to shock wave lithotripsy.

Science.gov (United States)

Cleveland, Robin O; Sapozhnikov, Oleg A

2005-10-01

A time-domain finite-difference solution to the equations of linear elasticity was used to model the propagation of lithotripsy waves in kidney stones. The model was used to determine the loading on the stone (principal stresses and strains and maximum shear stresses and strains) due to the impact of lithotripsy shock waves. The simulations show that the peak loading induced in kidney stones is generated by constructive interference from shear waves launched from the outer edge of the stone with other waves in the stone. Notably the shear wave induced loads were significantly larger than the loads generated by the classic Hopkinson or spall effect. For simulations where the diameter of the focal spot of the lithotripter was smaller than that of the stone the loading decreased by more than 50%. The constructive interference was also sensitive to shock rise time and it was found that the peak tensile stress reduced by 30% as rise time increased from 25 to 150 ns. These results demonstrate that shear waves likely play a critical role in stone comminution and that lithotripters with large focal widths and short rise times should be effective at generating high stresses inside kidney stones.

Perirenal hematomas induced by extracorporeal shock wave lithotripsy (ESWL). Therapeutic management.

Science.gov (United States)

Labanaris, Apostolos P; Kühn, Reinhard; Schott, Günter E; Zugor, Vahudin

2007-09-17

Extracorporeal shock wave lithotripsy (ESWL) is nowadays accepted as the treatment of choice for the majority of patients with renal or proximal ureteral calculi. Although, a relatively noninvasive modality with low morbidity, minor or major complications can be noted. A relative severe complication for the patient and confusing for the treating physician is the perirenal hematoma. With review the literature and an example of perirenal hematoma induced by ESWL in a patient treated in our department, we describe its therapeutic management.

Role of alpha-1 blocker in expulsion of stone fragments after extracorporeal shock wave lithotripsy for renal stones

International Nuclear Information System (INIS)

Pirzada, A.J.; Anwar, A.; Javed, A.; Memon, I.; Mohammad, A.

2011-01-01

Background: Renal stone disease is a significant and worldwide health problem. Recent advances in stone management have allowed kidney stones to be treated using extracorporeal shock wave lithotripsy (ESWL), uretero-renoscopy (URS), and percutaneous nephrostolithotomy (PCNL). Recently, medical expulsion therapy (MET) has been investigated as a supplement to observation in an effort to improve spontaneous stone passage rates. Patients and Methods: This study was a randomized, controlled, prospective study to determine whether the administration of Alpha-1-adrenergic receptor antagonists as an adjunctive medical therapy, increases the efficacy of ESWL to treat renal stones. Sixty patients with renal stones of 0.5-1.5 Cm in size (average size 1.2 Cm) were included in this study underwent ESWL followed by administration of Alpha-1-adrenergic receptor antagonists at department of Urology Liaquat National Hospital Karachi from Feb 2008 to Sept 2008. This was a comparative study and patients were divided into two groups. In group A patients received conventional treatment Diclofenac sodium, Anti Spasmodic (Drotaverine HCl) as required and Proton Pump inhibitor (Omeprazole 20 mg) once daily after shock wave lithotripsy. In group B patients received alpha-1 blocker, Alfuzosin HCl 5 mg twice daily in addition to conventional treatment. All patients were instructed to drink a minimum of 2 litres water daily. Ultrasound guided Dornier Alpha Impact Lithotripter was utilised for shock wave lithotripsy. Results: Of the 60 patients, 76.7% of those receiving Alfuzosin and 46.7% of controls had achieved clinical success at 1 month (p=0.01). The mean cumulative diclofenac dose was 485 mg per patient in the Alfuzosin group and 768 mg per patient in the control group (p=0.002). This difference was statistically significant. Conclusion: Alfuzosin therapy as an adjunctive medical therapy after ESWL is more effective than lithotripsy alone for the treatment of patients with large renal

Extracorporeal Shockwave Lithotripsy of Primary Intrahepatic Stones

Science.gov (United States)

Kim, Myung Hwan; Lee, Sung Koo; Min, Young Il; Lee, Mun Gyu; Sung, Kyu Bo; Cho, Kyung Sik; Lee, Sung Gyu; Min, Pyung Chul

1992-01-01

Extracorporeal shockwave lithothripsy (ESWL) was performed in intrahepatic stone patients (n = 18) by Dornier MPL 9,000 with ultrasound guidance. The patients had T-tube (n = 9) or percutaneous transhepatic biliary drainge tube (n = 9). Average treatment session was four and shock-wave numbers were in the range of 3,064 to 12,000 (average 6,288 shocks). Intrahepatic stones were removed completely in 16 patients over a 3 month period by ESWL and combined stone extraction maneuver such as cholangioscopic or interventional radiologic method. Extracorporeal shockwave lithothripsy was very helpful in facilitating extraction of stones in unfavorable locations or located above the severe stricture. In summary, extracorporeal Shockwave lithotripsy, followed by percutaneous stone extraction, will provide an improvement in the success rate and duration of treatment required for complete removal of primary hepatolithiasis. PMID:1477027

Second generation extracorporeal lithotripsy: Whither American radiologic leadership

International Nuclear Information System (INIS)

Pfister, R.C.

1987-01-01

Extracorporeal shock wave lithotripsy was developed by Dornier Medical Systems, Inc., and West German urologists. In the United States the marketing, training, and operation of these wet-tub units were limited to urologists. New dry-treatment lithotriptors are being developed in various countries, including the United States (Medstone), and will be marketed to radiologists, among others, once approved by the FDA for clinical use; future applications will include gallstones as well as renal calculi. Some of these new lithotripors are radiologically intensive, requiring US or fluroscopic guidance and radiography. Since the stone pulverization process in an image-controlled procedure, the units should be managed by radiologists; this will require supportive leadership from all current radiology department chiefs. This presentation reviews the lithotriptors available

CT evaluation of the kidneys following extracorporeal shock wave lithotripsy

International Nuclear Information System (INIS)

Rubin, J.I.; Arger, P.H.; Pollack, H.M.; Banner, M.P.; Coleman, B.G.; Mintz, M.C.; Van Arsdalen, K.N.

1986-01-01

CT scans of the kidneys were obtained iln 50 patients before and after extracorporeal shock wave lithotripsy (ESWL). Post-ESWL scans demonstrated subcapsular hematomas in eight (15%) and intrarenal hematomas in two (4%) patients. Water-density subcapsular collections were seen in three (6%) patients. Treated kidneys showed a mean increase in renal size of 9%. Perinephric stranding and fascial thickening were seen in 37 (70%) of 53 treated renal fossae. While most patients undergoing ESWL will show some posttreatment abnormality on CT, the procedure appears to be associated with a low incidence of serious renal trauma

CT appearance of renal hemorrhage after extracorporeal shock wave lithotripsy

Energy Technology Data Exchange (ETDEWEB)

Kanazawa, Susumu; Araki, Toru; Takamoto, Hitoshi; Hata, Kazuhiro

1988-07-01

Computed Tomography (CT) was performed in three patients who were suspicious of renal hemorrhage after extracorporeal shock wave lithotripsy (ESWL). Post-ESWL scans demonstrated subcapsular hematoma in all three cases, and intrarenal hemorrhage in two cases, one of which had fluid collection in the pararenal space and hemorrhage in the posterior pararenal space on CT. Thickening of gerota fascia and bridging septa in the perirenal space was visualized on CT in all of them. CT demonstrated clearly the anatomic distribution and extent of renal hemorrhage, and it is important to comprehend the imaging anatomy of the perirenal area for CT evaluation.

Characterization and modification of cavitation pattern in shock wave lithotripsy

Science.gov (United States)

Arora, Manish; Ohl, Claus Dieter; Liebler, Marko

2004-01-01

The temporal and spatial dynamics of cavitation bubble cloud growth and collapse in extracorporeal shock wave lithotripsy (ESWL) is studied experimentally. The first objective is obtaining reproducible cloud patterns experimentally and comparing them with FDTD-calculations. Second, we describe a method to modify the cavitation pattern by timing two consecutive pressure waves at variable delays. It is found that the spatial and temporal dynamics of the cavitation bubble can be varied in large ranges. The ability to control cavitation dynamics allows discussing strategies for improvement of medical and biological applications of shock waves such as cell membrane poration and stone fragmentation.

CT appearance of renal hemorrhage after extracorporeal shock wave lithotripsy

International Nuclear Information System (INIS)

Kanazawa, Susumu; Araki, Toru; Takamoto, Hitoshi; Hata, Kazuhiro

1988-01-01

Computed Tomography (CT) was performed in three patients who were suspicious of renal hemorrhage after extracorporeal shock wave lithotripsy (ESWL). Post-ESWL scans demonstrated subcapsular hematoma in all three cases, and intrarenal hemorrhage in two cases, one of which had fluid collection in the pararenal space and hemorrhage in the posterior pararenal space on CT. Thickening of gerota fascia and bridging septa in the perirenal space was visualized on CT in all of them. CT demonstrated clearly the anatomic distribution and extent of renal hemorrhage, and it is important to comprehend the imaging anatomy of the perirenal area for CT evaluation. (author)

Development of a new diagnostic sensor for extra-corporeal shock-wave lithotripsy

International Nuclear Information System (INIS)

Fedele, F; Coleman, A J; Leighton, T G; White, P R; Hurrell, A M

2004-01-01

Extracorporeal shock-wave lithotripsy is the leading technique used in urology for the non-invasive treatment of kidney and ureteric stones. The stone is comminuted by thousands of ultrasound shocks, into fragments small enough to be naturally passed. Since the technique was introduced in the 1980 different generations of lithotripters have been developed. Nevertheless the alignment systems (x-ray, ultrasound) still have some limitations (indeed, the tighter focusing of newer lithotripter reduces the tolerance for misalignment) and there is no capability for on-line monitoring of the degree of fragmentation of the stone. There is 50% incidence of re-treatments, possibly due to these deficiencies. The objective of this research is to design a new passive acoustic sensor, exploiting the secondary acoustic emission generated during the treatment, which could be used as a diagnostic device for lithotripsy. With a passive cylindrical cavitation detector, developed by the National Physical Laboratory, it was possible to detect these emissions in a laboratory lithotripter, and it was shown that they contain information on the degree of stone fragmentation and stone location. This information could be used to perform the desired monitoring and to improve the stone targeting. In collaboration with Precision Acoustic Ltd, some clinical prototypes were developed and tested to verify the relevance of these preliminary results. Clinical results are presented

Development of a new diagnostic sensor for extra-corporeal shock-wave lithotripsy

Energy Technology Data Exchange (ETDEWEB)

Fedele, F [Medical Physics Department, Guy' s and St Thomas' NHS Trust, London, SE1 7EH (United Kingdom); Coleman, A J [Medical Physics Department, Guy' s and St Thomas' NHS Trust, London, SE1 7EH (United Kingdom); Leighton, T G [Institute of Sound and Vibration Research, University of Southampton, Southampton, SO17 1BJ (United Kingdom); White, P R [Institute of Sound and Vibration Research, University of Southampton, Southampton, SO17 1BJ (United Kingdom); Hurrell, A M [Precision Acoustics Ltd, Dorchester, DT1 1PY (United Kingdom)

2004-01-01

Extracorporeal shock-wave lithotripsy is the leading technique used in urology for the non-invasive treatment of kidney and ureteric stones. The stone is comminuted by thousands of ultrasound shocks, into fragments small enough to be naturally passed. Since the technique was introduced in the 1980 different generations of lithotripters have been developed. Nevertheless the alignment systems (x-ray, ultrasound) still have some limitations (indeed, the tighter focusing of newer lithotripter reduces the tolerance for misalignment) and there is no capability for on-line monitoring of the degree of fragmentation of the stone. There is 50% incidence of re-treatments, possibly due to these deficiencies. The objective of this research is to design a new passive acoustic sensor, exploiting the secondary acoustic emission generated during the treatment, which could be used as a diagnostic device for lithotripsy. With a passive cylindrical cavitation detector, developed by the National Physical Laboratory, it was possible to detect these emissions in a laboratory lithotripter, and it was shown that they contain information on the degree of stone fragmentation and stone location. This information could be used to perform the desired monitoring and to improve the stone targeting. In collaboration with Precision Acoustic Ltd, some clinical prototypes were developed and tested to verify the relevance of these preliminary results. Clinical results are presented.

Radiation exposure to patients during extracorporeal shock wave lithotripsy

International Nuclear Information System (INIS)

Van Swearingen, F.L.; McCullough, D.L.; Dyer, R.; Appel, B.

1987-01-01

Extracorporeal shock wave lithotripsy is rapidly becoming an accepted treatment of renal calculi. Since fluoroscopy is involved to image the stones it is important to know how much radiation the patient receives during this procedure. Surface radiation exposure to the patient was measured in more than 300 fluoroscopic and radiographic procedures using thermoluminescent dosimeters. Initial results showed an average skin exposure of 10.1 rad per procedure for each x-ray unit, comparing favorably with exposure rates for percutaneous nephrostolithotomy and other routine radiological procedures. Factors influencing exposure levels include stone characteristics (location, size and opacity), physician experience and number of shocks required. Suggestions are given that may result in a 50 per cent reduction of radiation exposure

Contemporary trends in urinary tract stone surgery, a regional perspective: Auckland, New Zealand.

Science.gov (United States)

Acland, George; Zargar-Shoshtari, Kamran; Rice, Michael

2016-04-01

The aim of the study is to assess the contemporary patterns of utilization of various therapeutic options for the management of nephrolithiasis in our tertiary referral institution in Auckland, New Zealand. A retrospective audit was conducted for all urinary stone procedures between January 2007 and December 2013. Procedure-related information was collected for each year. All elective and emergency procedures were included. Data were collected on the elective waiting lists for each procedure. A total of 5512 stone-related cases were performed during the study period. Six hundred and fifty-three cases were performed in 2007 compared with 945 in 2013. Total number of percutaneous nephrolithotomy (PCNLs) performed, as well as the proportion of PCNL cases, demonstrated a significant decline from 84 (12.9%) in 2007 to 67 (7.1%) in 2013. While the annual numbers of extracorporeal shock wave lithotripsy (ESWLs) have increased, the percentage of ESWLs performed relative to total stone procedures has declined from 33% to 23% over the last 4 years of this audit. There has been a significant rise in the numbers of rigid and flexible ureteroscopies, with these now being the most utilized procedure. The number of patients awaiting elective procedures declined over the duration of this audit, with an associated improvement in meeting annual demand for treatment of nephrolithiasis from 78% in 2007 to 91% in 2013. A proportional decline in PCNL and ESWL utilization with a significant increase in flexible and rigid ureteroscopic procedures has been observed over this time and this pattern has been associated with improved adherence to surgical targets despite an increasing number of cases. © 2015 Royal Australasian College of Surgeons.

EXTRACORPOREAL SHOCKWAVE LITHOTRIPSY (ESWL PADA BATU GINJAL

Directory of Open Access Journals (Sweden)

Anak Agung Sri Satyawati

2014-09-01

Full Text Available Latar Belakang. Extracorporeal shockwave lithotripsy (ESWL merupakan pilihan terapi yang paling cost effective pada kasus kasus batu ginjal, namun sayangnya modalitas terapi ini belum banyak dipilih karena dianggap mahal dan kurangnya informasi mengenai keuntungan penggunaannya. Kasus. Perempuan usia 65 tahun mengeluh nyeri pinggang yang dirasakan mendadak dan semakin memberat  sejak 2 bulan sebelum masuk rumah sakit, disertai mual dan penurunan nafsu makan. Berdasarkan pemeriksaan foto polos abdomen dan USG Urologi  didapatkan kesan adanya batu renal dekstra ukuran 16mm x 18mm, dengan hidronefrosis derajat I renal dekstra. Kemudian dilakukan tindakan ESWL. Hasil. Setelah dilakukan tindakan ESWL berupa penghantaran gelombang kejut pada permukaan ginjal  kanan selama 20-30 menit, keluar pecahan pecahan kecil batu kalsium. Berdasarkan pemeriksaan radiografi post ESWL tidak ditemukan gambaran radioopak pada kaliks ginjal, ureter maupun kandung kemih. Kesimpulan. Batu kalsium dengan ukuran 16mm x 18mm pada renal dekstra berhasil dikeluarkan total tanpa adanya komplikasi.

Radiation Dose Assesment And Risk Estimation During Extracorporeal Shock Wave Lithotripsy

International Nuclear Information System (INIS)

Sulieman, A.; Ibrahim, A.A.; Osman, H.; Yousef, M.

2011-01-01

Extracorporeal shockwave lithotripsy (ESWL) is considered the gold standard for calculi fragmentation. The aims of this study are to measure the entrance surface dose (ESD) using thermo-luminescence dosimeter (TLDs) and to estimate the probability of carcinogenesis during ESWL procedure. The study was carried out at two centers (Group A, 50 patients) and (Group B, 25 patients). The mean ESD and effective doses were 36 mGy and 34 mSv. The results show that the probability of carcinogenesis is a tiny value 100 per million patients) but the main biological effect is occurring due to the accumulative impact of radiation.

Spleen injury following left extracorporeal shockwave lithotripsy (ESWL).

Science.gov (United States)

Marinkovic, Serge P; Marinkovic, Christina M; Xie, Donghua

2015-02-18

A splenic rupture associated with extracorporeal shockwave lithotripsy (ESWL) is exceedingly rare. We report a case of stage 3 splenic laceration, hemoperitoneum and subsequent splenic rupture following an ESWL for a left mid polar renal calculus. During the ESWL, although the patient's pain was controlled the gentleman was very nervous and had to be repositioned eight individual times. Approximately 6 hours after the ESWL, the patient phoned the urologist complaining of severe left flank pain unlike any previous episode of renal colic. A computerized tomography (CT) scan demonstrated a stage 3 splenic injury with hemoperitoneum. The patient decompensated and an emergent splenectomy was then performed and the patient experienced an uneventful recovery. Splenic injury likely results from unintentional movement during the sound wave administration for the stone fragmentation procedure. Utilizing noise cancelling headphones during ESWL may preclude the potential pitfalls of patient nervousness.

Endoscopic Stone Measurement During Ureteroscopy.

Science.gov (United States)

Ludwig, Wesley W; Lim, Sunghwan; Stoianovici, Dan; Matlaga, Brian R

2018-01-01

Currently, stone size cannot be accurately measured while performing flexible ureteroscopy (URS). We developed novel software for ureteroscopic, stone size measurement, and then evaluated its performance. A novel application capable of measuring stone fragment size, based on the known distance of the basket tip in the ureteroscope's visual field, was designed and calibrated in a laboratory setting. Complete URS procedures were recorded and 30 stone fragments were extracted and measured using digital calipers. The novel software program was applied to the recorded URS footage to obtain ureteroscope-derived stone size measurements. These ureteroscope-derived measurements were then compared with the actual-measured fragment size. The median longitudinal and transversal errors were 0.14 mm (95% confidence interval [CI] 0.1, 0.18) and 0.09 mm (95% CI 0.02, 0.15), respectively. The overall software accuracy and precision were 0.17 and 0.15 mm, respectively. The longitudinal and transversal measurements obtained by the software and digital calipers were highly correlated (r = 0.97 and 0.93). Neither stone size nor stone type was correlated with error measurements. This novel method and software reliably measured stone fragment size during URS. The software ultimately has the potential to make URS safer and more efficient.

Emphysematous pyelonephritis: A rare life-threatening complication after extracorporeal shock wave lithotripsy

International Nuclear Information System (INIS)

Kim, Su Ho; Chung, Dong Jin; Yeo, Dong Myung; Sonh, Dong Wan; Hahn, Sung Tae

2015-01-01

Emphysematous pyelonephritis (EPN), caused by extracorporeal shock wave lithotripsy (ESWL), has not been reported in the literature; and the mechanism of this disease is unknown. Although many studies have conjectured about the various causes of EPN, ESWL was not one of them. The patient in this report was a 65-year-old woman with a past medical history of diabetes; the patient underwent an ESWL that caused the EPN. To the best of our knowledge, this is the first report of an EPN case that was caused by ESWL

Emphysematous pyelonephritis: A rare life-threatening complication after extracorporeal shock wave lithotripsy

Energy Technology Data Exchange (ETDEWEB)

Kim, Su Ho; Chung, Dong Jin; Yeo, Dong Myung; Sonh, Dong Wan; Hahn, Sung Tae [Yeouido St. Mary' s Hospital, College of Medicine, The Catholic University of Korea, Seoul (Korea, Republic of)

2015-09-15

Emphysematous pyelonephritis (EPN), caused by extracorporeal shock wave lithotripsy (ESWL), has not been reported in the literature; and the mechanism of this disease is unknown. Although many studies have conjectured about the various causes of EPN, ESWL was not one of them. The patient in this report was a 65-year-old woman with a past medical history of diabetes; the patient underwent an ESWL that caused the EPN. To the best of our knowledge, this is the first report of an EPN case that was caused by ESWL.

Surface dose of X rays to patients during extracorporeal shock wave lithotripsy

International Nuclear Information System (INIS)

Jiang Qingqi; Weng Zhigeng; Feng Ming; Wang Guomin.

1990-01-01

During extracorporeal shock wave lithotripsy (ESWL), the fluoroscopy must be made to show the location and size of the stone thus the patient has to be exposed to X rays. The surface dose to patients during ESWL was measured in an investigation on 134 cases of renal lithiasis admitted in a certain hospital of Shanghai. The results show that the average skin dose equivalent for these patients was 162 mSv and the magnitude of doses was depended upon some factors such as the size and location of the stone

Usefulness of Early Extracorporeal Shock Wave Lithotripsy in Colic Patients with Ureteral Stones

OpenAIRE

Choi, Hyeung Joon; Jung, Jin-Hee; Bae, Jungbum; Cho, Min Chul; Lee, Hae Won; Lee, Kwang Soo

2012-01-01

Purpose To compare efficacy and safety between early extracorporeal shock wave lithotripsy (eESWL) and deferred ESWL (dESWL) in colic patients with ureteral stones and to investigate whether eESWL can play a critical role in improving treatment outcomes. Materials and Methods A total of 279 patients who underwent ESWL for single radio-opaque ureteral stones of 5 to 20 mm in size were included in this retrospective study. The patients were categorized into two groups according to the time betw...

Stenting and extracorporeal shock wave lithotripsy in chronic pancreatitis

DEFF Research Database (Denmark)

Holm, M; Matzen, Peter

2003-01-01

BACKGROUND: Early observational studies of endoscopic treatment and extracorporeal shock wave lithotripsy (ESWL) reported considerable or complete relief of pain in 50%-80% of patients with chronic pancreatitis. There is no consensus on the measurement of pain, making comparison of observational...... studies difficult, and little attention has been paid to the type and amount of analgesics used by patients before and after decompressive treatment. METHODS: We performed a retrospective study of all patients with chronic pancreatitis and large-duct disease and receiving decompressing treatment between 1...... November 1994 and 31 July 1999. Primary parameters were type and amount of analgesics used. RESULTS: Forty-nine patients with chronic pancreatitis and large-duct disease received stenting of the pancreatic duct (28 patients), ESWL (6 patients) or both (15 patients). After a median follow-up of 21 months...

MR imaging of kidneys following extracorporeal shock wave lithotripsy

International Nuclear Information System (INIS)

Baumgartner, B.R.; Dickey, K.W.; Nelson, R.C.; Ambrose, S.S.; Walton, K.N.; Bernardino, M.E.

1986-01-01

MR images were obtained the day after extracorporeal shock wave lithotripsy (ESWL) therapy in 34 patients; the untreated kidneys served as controls. Five patients underwent ESWL of both kidneys before MR imaging. The kidneys were imaged with a spin-echo technique. Multisection coronal, sagittal, and axial images were obtained with T1-weighted pulse sequences. MR imaging studies of 39 kidneys after ESWL showed no abnormality in ten (25%) cases. The other kidneys (75%) had one or more of several findings. Small subcapsular or perinephric fluid collections were noted in ten (25%) patients. Generalized loss of corticomedullary junction (CMJ) was noted in eight (21%) cases and focal loss in 16 (24%). The more pronounced alterations in the CMJ correlated with increased numbers of shock waves received by the kidney

Arrhythmia during extracorporeal shock wave lithotripsy.

Science.gov (United States)

Zeng, Z R; Lindstedt, E; Roijer, A; Olsson, S B

1993-01-01

A prospective study of arrhythmia during extracorporeal shock wave lithotripsy (ESWL) was performed in 50 patients, using an EDAP LT01 piezoelectric lithotriptor. The 12-lead standard ECG was recorded continuously for 10 min before and during treatment. One or more atrial and/or ventricular ectopic beats occurred during ESWL in 15 cases (30%). The occurrence of arrhythmia was similar during right-sided and left-sided treatment. One patient developed multifocal ventricular premature beats and ventricular bigeminy; another had cardiac arrest for 13.5 s. It was found that various irregularities of the heart rhythm can be caused even by treatment with a lithotriptor using piezoelectric energy to create the shock wave. No evidence was found, however, that the shock wave itself rather than vagal activation and the action of sedo-analgesia was the cause of the arrhythmia. For patients with severe underlying heart disease and a history of complex arrhythmia, we suggest that the ECG be monitored during treatment. In other cases, we have found continuous monitoring of oxygen saturation and pulse rate with a pulse oximeter to be perfectly reliable for raising the alarm when depression of respiration and vaso-vagal reactions occur.

Cavitation phenomena in extracorporeal microexplosion lithotripsy

Science.gov (United States)

Tomita, Y.; Obara, T.; Takayama, K.; Kuwahara, M.

1994-09-01

An experimental investigation was made of cavitation phenomena induced by underwater shock wave focusing applied to the extracorporeal microexplosion lithotripsy (microexplosion ESWL). Firstly an underwater microexplosion generated by detonation of a 10 mg silver azide pellet was studied and secondly underwater shock focusing and its induced cavitation phenomena were investgated. Underwater shock wave was focused by using a semi-ellipsoidal reflector in which a shock wave generated at the first focal point of the reflector was reflected and focused at the second focal point. It is found that an explosion product gas bubble did not produce any distinct rebound shocks. Meantime cavitation appeared after shock focusing at the second focal point where expansion waves originated at the exit of the reflector were simultaneously collected. A shock/bubble interaction is found to contribute not only to urinary tract stone disintegration but also tissue damage. The cavitation effect associated with the microexplosion ESWL was weaker in comparison with a spark discharge ESWL. The microexplosion ESWL is an effective method which can minimize the number of shock exposures hence decreasing tissue damage by conducting precise positioning of urinary tract stones.

Morphological alterations of the gall-bladder following extracorporeal shock-wave lithotripsy

International Nuclear Information System (INIS)

Schumacher, K.A.; Zoeller, A.; Swobodnik, W.; Janowitz, P.

1990-01-01

The present study reports on 51 patients with symptomatic cholecystolithiasis, who accordingly underwent extracorporeal shock-wave lithotripsy (ESWL). In all cases, computed tomography (CT) was performed prior to and after the therapeutic procedure to delineate changes in gall-bladder morphology. Slight edematous thickening of the gall-bladder wall was found in 15 patients. One patient presented a rupture of the gall-bladder with formation of a bilioma in the adjacent liver tissue. In case of calcific concrements, CT revealed a characteristic pattern of fragment distribution following shock-wave treatment, and fragments of various sizes exhibited distinct adhesion to the gall-bladder wall. (orig.) [de

[Renal hematoma after extracorporeal shockwave lithotripsy in a series of 324 consecutive sessions with the DOLI-S lithotripter: incidents, characteristrics, multifactorial analysis and review].

Science.gov (United States)

Orozco Fariñas, Rodolfo; Iglesias Prieto, José Ignacio; Massarrah Halabi, Jorge; Mancebo Gómez, José M; Perez-Castro Ellendt, Enrique

2008-10-01

The objective is to know the prevalence of renal hematoma after lithotripsy in our unit, as well as the incidence of symptomatic and/or progressive hematomas, their clinical behavior and management, and also the factors potentially influencing those features. A prospective study in which we analyzed various parameters from the database on 314 patients undergoing SWL on 324 renal units. SPSS 15.01 was employed for statistical analysis under supervision of biostatistics experts. The diagnosis of hematoma was obtained with clinical data (history and physical examination), blood analysis, and ultrasound, this latter with the complement of CT scan in isolated cases. All patients underwent follow-up by means of phone contacts over a period between 7-19 months after lithotripsy. The prevalence of hematoma was 13% but only 6.2% were symptomatic. Accumulated incidence of hematoma with progressive evolution was 2.16%, and blood transfusion requirement due to hematoma was 0.92% of all lithotripsies, which represents 7.14% or them. Factors statistically associated with the incidence of hematoma were: number of shock waves (over 2300), total energy (above 150J), number of KV (above 17.5), preoperative microhematuria, perioperative hypertension, cystine lithiasis, hydrocalyx, caliceal localizations (mainly lower calyces), the association of coronary artery disease with hypertension, or hepatic diseases, chronic hepatopathy, elevation of transaminases, usual intake of anti platelet aggregation drugs and nonsteroidal anti-inflammatory drugs (mainly with prior low-weight heparin treatment for hematoma progression), and a combination of the previous with preoperative hypertension (for symptomatic hematoma), as well as the presence of multiple stones treated in the some session, with different degrees of association for the various subgroups of hematomas. We observed differences in clinical behavior depending on the type of hematoma (subcapsular and perirenal) and 12% of the patients

Unexpected difficulties in randomizing patients in a surgical trial: A prospective study comparing extracorporeal shock wave lithotripsy with open cholecystectomy

NARCIS (Netherlands)

P.W. Plaisier; M.Y. Berger (Marjolein); R.L. van der Hul (René); H.G. Nijs (Huub); R. den Toom (Rene); O.T. Terpstra (Onno); H.A. Bruining (Hajo); S.M. Strasberg (S.)

1994-01-01

textabstractShortly after extracorporeal shock wave lithotripsy (ESWL) was introduced as a promising new treatment modality for gallstone disease, a randomized controlled study was performed to assess the cost-effectiveness of ESWL compared to open cholecystectomy, the gold standard. During the

[Prospective evaluation of pain associated with indwelling JJ stents following ureterorenoscopic lithotripsy].

Science.gov (United States)

Dudek, Przemysław; Gołabek, Tomasz; Jaskulski, Jarosław; Orłowski, Paweł; Bukowczan, Jakub; Szopiński, Tomasz; Chłosta, Piotr

2013-01-01

Routine placement of JJ ure teric stents, following uncomplicated endoscopic removal of a ureteral stone, still remains debatable. Indwelling JJ stents are not without any risks. They often can cause marked discomfort, or even pain. The aim of this study was to prospectively evaluate patient's perceived pain due to renal colic and indwelling JJ stent left following ure terorenoscopic lithotripsy (URSL). 54 patients with colicky pain due to distal ureteric stone, and who underwent uncompli cated ureterorenoscopic lithotripsy, were included in the study. Follow ing URSL, patients were randomly selected to have either JJ stent left in situ (Group I), or remain without a stent (Group II). Among all study par ticipants levels of pain prior, as well as 14 days after the procedure were evalu ated with the use of a visual analogue pain scale. Pain perception at the time of colic did not vary between men and women (6.30 +/- 1.33 and 6.38 +/- 1.11, respectively, p=0.293). Similarly, no differences in perceived pain were noted 14 days following URSL. Mean pain score in patients with indwelling JJ stent was 2.12 +/- 1.23 as compared to 2.15 +/- 0.67 in those without it (p=0.148). No increase in pain levels due to indwelling JJ stent could be observed. Further research to allow for better assessment of discomfort and pain caused by an indwelling JJ stent on a larger cohort, and which could also discriminate patients' psy chosomatic symptoms, is needed.

Comparative Study between Slow Shock Wave Lithotripsy and Fast Shock Wave Lithotripsy in the Management of Renal Stone

Directory of Open Access Journals (Sweden)

AKM Zamanul Islam Bhuiyan

2013-01-01

Full Text Available Background: Renal calculi are frequent causes of ureteric colic. Extracorporeal shock wave lithotripsy is the most common treatment of these stones. It uses focused sound waves to break up stones externally. Objective: To compare the efficiency of slow and fast delivery rate of shock waves on stone fragmentation and treatment outcome in patients with renal calculi. Materials and Methods: This prospective study was done in the department of Urology, National Institute of Kidney diseases and Urology, Sher-e-Bangla Nagar, Dhaka from July 2006 to June 2007. Total 90 patients were treated using the Storz Medical Modulith ® SLX lithotripter. Patients were divided into Group A, Group B and Group C – each group having 30 subjects. Group A was selected for extracorporeal shockwave lithotripsy (ESWL by 60 shock waves per minute, Group B by 90 shock waves per minute and Group C by 120 shock waves per minute. Results: Complete clearance of stone was observed in 24 patients in Group A and 13 patients in both Group B and Group C in first session. In Group A only 3 patients needed second session but in Group B and Group C, 12 and 8 patients needed second session. In Group A only one patient needed third session but third session was required for 3 patients in Group B and 5 patients in Group C for complete clearance of stone. In Group A, subsequent sessions were performed under spinal anesthesia and in Group B under sedation and analgesia (p>0.001. Mean number of sessions for full clearance of stones in group A was 1.37 ± 0.85, in Group B was 1.8 ± 0.887 and in Group C was 2.0 ± 1.083. Significant difference was observed in term of sessions among groups (p>0.05. In first follow-up, complete clearance of stones was seen in 24 patients in Group A and 13 in both Group B and Group C. In second follow-up, 3 patients in Group A, 12 in Group B and 8 in Group C showed complete clearance of stones. It was observed that rate of stone clearance was higher in Group A

Dependence of calculus retropulsion dynamics on fiber size and radiant exposure during Ho:YAG lithotripsy.

Science.gov (United States)

Lee, Ho; Ryan, Robert T; Kim, Jeehyun; Choi, Bernard; Arakeri, Navanit V; Teichman, Joel M H; Welch, A J

2004-08-01

During pulsed laser lithotripsy, the calculus is subject to a strong recoil momentum which moves the calculus away from laser delivery and prolongs the operation. This study was designed to quantify the recoil momentum during Ho:YAG laser lithotripsy. The correlation among crater shape, debris trajectory, laser-induced bubble and recoil momentum was investigated. Calculus phantoms made from plaster of Paris were ablated with free running Ho:YAG lasers. The dynamics of recoil action of a calculus phantom was monitored by a high-speed video camera and the laser ablation craters were examined with Optical Coherent Tomography (OCT). Higher radiant exposure resulted in larger ablation volume (mass) which increased the recoil momentum. Smaller fibers produced narrow craters with a steep contoured geometry and decreased recoil momentum compared to larger fibers. In the presence of water, recoil motion of the phantom deviated from that of phantom in air. Under certain conditions, we observed the phantom rocking towards the fiber after the laser pulse. The shape of the crater is one of the major contributing factors to the diminished recoil momentum of smaller fibers. The re-entrance flow of water induced by the bubble collapse is considered to be the cause of the rocking of the phantom.

Extracorporeal shock wave lithotripsy: What is new?

Science.gov (United States)

Bach, Christian; Karaolides, Theocharis; Buchholz, Noor

2012-01-01

Objectives Thirty years after its introduction, extracorporeal shockwave lithotripsy (ESWL) is still first-line treatment for more than half of all urinary tract stones, but machines and treatment strategies have significantly developed over time. In this review, we summarise the latest knowledge about the clinically important aspects of ESWL. Methods We searched PubMed to identify relevant reports and the latest European Association of Urology guidelines, and standard urological textbooks were consulted. Results New technical developments include: Twin-head and tandem-pulse shock-wave generators; wide-focus, low-pressure systems; optimised coupling; and automated location and acoustic tracking systems. Indications have been refined, making possible the identification of patients in whom ESWL treatment is likely to fail. By lowering the shock-wave rate, improving coupling, applying abdominal compression, power ‘ramping’ and postoperative medical expulsion therapy, treatment protocols have been optimised. Conclusions Promising new technical developments are under development, with the potential to increase the stone-free rate after ESWL. For optimal results, the refined indications need to be respected and optimised treatment protocols should be applied. PMID:26558039

UNEXPECTED DIFFICULTIES IN RANDOMIZING PATIENTS IN A SURGICAL TRIAL - A PROSPECTIVE-STUDY COMPARING EXTRACORPOREAL SHOCK-WAVE LITHOTRIPSY WITH OPEN CHOLECYSTECTOMY

NARCIS (Netherlands)

PLAISIER, PW; BERGER, MY; VANDERHUL, RL; NIJS, HGT; DENTOOM, R; TERPSTRA, OT; BRUINING, HA

1994-01-01

Shortly after extracorporeal shock wave lithotripsy (ESWL) was introduced as a promising new treatment modality for gallstone disease, a randomized controlled study was performed to assess the cost-effectiveness of ESWL compared to open cholecystectomy, the gold standard. During the performance of

Factors influencing radiation exposure during the extracorporeal shock wave lithotripsy

Energy Technology Data Exchange (ETDEWEB)

Wei Chuan Chen; Ying Huei Lee; Ming Tsun Chen; Jong Khing Huang; Luke S Chang (Division of Urology, Dept. of Surgery, National Yang-Ming Medical College and Veterans General Hospital-Taipei, Taiwan (China))

1991-01-01

A prospective evaluation of 89 consecutive sessions of extracorporeal shock wave lithotripsy (ESWL) was undertaken to try and find the best way of minimising the amount of exposure to radiation. Forty-two patients were randomly allocated to undergo ESWL treatment by experienced surgeons (group A), and 47 to undergo the treatment by inexperienced surgeons (group B). The mean calculated entrance radiation exposure was 3.01 rads (group A: 2.64 (0.97) rads, range 1.00-4.48, group B: 3.38 (0.86) rads, range 1.11-5.75). Among factors that influenced radiation exposure, the tissue: air ratio should be borne in mind and the level of skill in controlling movement of gantry was the most important in reducing the exposure to radiation. (au).

Factors influencing radiation exposure during the extracorporeal shock wave lithotripsy

International Nuclear Information System (INIS)

Wei Chuan Chen; Ying Huei Lee; Ming Tsun Chen; Jong Khing Huang; Luke S Chang

1991-01-01

A prospective evaluation of 89 consecutive sessions of extracorporeal shock wave lithotripsy (ESWL) was undertaken to try and find the best way of minimising the amount of exposure to radiation. Forty-two patients were randomly allocated to undergo ESWL treatment by experienced surgeons (group A), and 47 to undergo the treatment by inexperienced surgeons (group B). The mean calculated entrance radiation exposure was 3.01 rads (group A: 2.64 (0.97) rads, range 1.00-4.48, group B: 3.38 (0.86) rads, range 1.11-5.75). Among factors that influenced radiation exposure, the tissue: air ratio should be borne in mind and the level of skill in controlling movement of gantry was the most important in reducing the exposure to radiation. (au)

The effect and influence of lumen holmium laser lithotripsy on serum oxidative stress proteins and inflammatory factors of ureteral calculi patients

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Fan Zhang

2016-09-01

Full Text Available Objective: To investigate the effect and influence of lumen holmium laser lithotripsy on treating serum oxidative stress proteins and inflammatory factors of patients with ureteral calculi. Methods: A total of 120 cases of patients with ureteral calculi treated in our hospital from May 2010 to Nov 2014 were enrolled in this research for an analysis study. The effect and influence on serum oxidative stress proteins and inflammatory factors of lumen holmium laser lithotripsy on ureteral calculi patients were assayed. Then 120 cases of healthy subjects in our hospital at the same period were taken as control. Results: Among the 120 cases of ureteral calculi patients, 113 cases of patients showed successful operation, with a success rate of 94.2%. The average calculi-discharged time was (28.4 ± 11.2 d and the average operation time was (58.9 ± 10.7 min, while the postoperative hospital stay is (3.8 ± 1.2 d. The results also showed that the levels of NOX1. NOX3, NOX4 and NOX5, and levels of interleukin-2 (IL-2, IL-6, IL-10 and TNF-α of patients with ureteral calculi were significantly higher, compared with the control group, and these parameters were normalized greatly after operation with that the levels of them were significantly different from those before operation. Conclusion: Lumen holmium laser lithotripsy exerts a significant effect on ureteral calculi patients and the oxidative stress parameters and inflammatory factor were normalized greatly.

Role of US in the evaluation of patients after extracorporeal shock wave lithotripsy

International Nuclear Information System (INIS)

Nadel, S.N.; St Amour, T.E.; McClennan, B.L.; Ling, D.; Clayman, R.V.

1986-01-01

Five hundred patients underwent extracorporeal shock wave lithotripsy (ESWL) during a 9-month period and 343 were evaluated afterward with high-resolution realtime US. US examinations were correlated with the clinical course, other imaging studies, and patient outcome. US was as sensitive as but less specific than plain radiography for the detection of fragmented calculi. US successfully graded hydronephrosis, imaged fluid collections, and facilitated placement of percutaneous nephrostomy tubes. The limitations of US included loss of detail secondary to indwelling catheters, ileus, reflections from adjacent bowel, and operator or machine dependence

Some health physics implications of extracorporeal shock wave lithotripsy

International Nuclear Information System (INIS)

Henderson, J.E.

1987-01-01

Extracorporeal Shock Wave Lithotripsy (ESWL) is a relatively new, noninvasive technique for the destruction of renal calculi (kidney stones) in vivo. X-ray localizing techniques are used to position the stone for shock wave destruction. The combination of radiographic and fluoroscopic exposure contributes significantly to patient dose. This presentation considers alternative techniques for measuring patient exposure during ESWL and details many of the problems attendant to those measurements. Factors that contribute to patient dose are described. Comparisons are made to previous interventions for renal calculi involving radiological considerations. Operator exposures are negligible for this procedure, but skin entrance exposures for patients have been found on the order of 10 R to 17 R. Attempts to quantify gonadal doses during ESWL treatment at the University of Virginia are described. A rationale for continued studies in this area is offered

Numerical Response Surfaces of Volume of Ablation and Retropulsion Amplitude by Settings of Ho:YAG Laser Lithotripter

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Jian J. Zhang

2018-01-01

Full Text Available Objectives. Although laser lithotripsy is now the preferred treatment option for urolithiasis due to shorter operation time and a better stone-free rate, the optimal laser settings for URS (ureteroscopic lithotripsy for less operation time remain unclear. The aim of this study was to look for quantitative responses of calculus ablation and retropulsion by performing operator-independent experiments to determine the best fit versus the pulse energy, pulse width, and the number of pulses. Methods. A lab-built Ho:YAG laser was used as the laser pulse source, with a pulse energy from 0.2 J up to 3.0 J and a pulse width of 150 μs up to 1000 μs. The retropulsion was monitored using a high-speed camera, and the laser-induced craters were evaluated with a 3-D digital microscope. The best fit to the experimental data is done by a design of experiment software. Results. The numerical formulas for the response surfaces of ablation speed and retropulsion amplitude are generated. Conclusions. The longer the pulse, the less the ablation or retropulsion, while the longer pulse makes the ablation decrease faster than the retropulsion. The best quadratic fit of the response surface for the volume of ablation varied nonlinearly with pulse duration and pulse number.

Numerical Response Surfaces of Volume of Ablation and Retropulsion Amplitude by Settings of Ho:YAG Laser Lithotripter

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Rutherford, Jonathan; Solomon, Metasebya; Cheng, Brian; Xuan, Jason R.; Gong, Jason; Yu, Honggang; Xia, Michael L. D.; Yang, Xirong; Hasenberg, Thomas; Curran, Sean

2018-01-01

Objectives Although laser lithotripsy is now the preferred treatment option for urolithiasis due to shorter operation time and a better stone-free rate, the optimal laser settings for URS (ureteroscopic lithotripsy) for less operation time remain unclear. The aim of this study was to look for quantitative responses of calculus ablation and retropulsion by performing operator-independent experiments to determine the best fit versus the pulse energy, pulse width, and the number of pulses. Methods A lab-built Ho:YAG laser was used as the laser pulse source, with a pulse energy from 0.2 J up to 3.0 J and a pulse width of 150 μs up to 1000 μs. The retropulsion was monitored using a high-speed camera, and the laser-induced craters were evaluated with a 3-D digital microscope. The best fit to the experimental data is done by a design of experiment software. Results The numerical formulas for the response surfaces of ablation speed and retropulsion amplitude are generated. Conclusions The longer the pulse, the less the ablation or retropulsion, while the longer pulse makes the ablation decrease faster than the retropulsion. The best quadratic fit of the response surface for the volume of ablation varied nonlinearly with pulse duration and pulse number. PMID:29707187

Extracorporeal shock wave lithotripsy in the treatment of renal pelvicalyceal stones in morbidly obese patients

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V. A. Mezentsev

2005-04-01

Full Text Available INTRODUCTION: Management of urolithiasis in morbidly obese patients is usually associated with higher morbidity and mortality compared to non-obese patients. In morbidly obese patients, since the kidney and stone are at a considerable distance from the skin (compared to non-obese patients difficulty may be found in positioning the patient so that the stone is situated at the focal point of the lithotripter. OBJECTIVE: To evaluate the outcomes and cost-efficiency of extracorporeal shock wave lithotripsy (ESWL in the treatment of renal pelvicalyceal stones sized between 6 and 20 mm in morbidly obese patients. MATERIALS AND METHODS: Using various aids, such as mobile overtable module, extended shock pathway and abdominal compression 37 patients with body mass index more than 40 kg/m2 were treated using the Siemens Lithostar-plus third generation lithotripter. The size of renal pelvicalyceal stones was between 6 and 20 mm. Treatment costs for shock wave lithotripsy were calculated. RESULTS: The overall stone free rate at 3 months of 73% was achieved. The mean number of treatments per patient was 2.1. The post-lithotripsy secondary procedures rate was 5.4%. No complications, such as subcapsular haematoma or acute pyelonephritis were recorded. The most effective (87% success rate and cost-efficient treatment was in the patients with pelvic stones. The treatment of the patients with low caliceal stones was effective in 60% only. The cost of the treatment of the patients with low calyceal stones was in 1.8 times higher than in the patients with pelvic stones. CONCLUSION: We conclude that ESWL with the Siemens Lithostar-plus is the most effective and cost-efficient in morbidly obese patients with pelvic stones sized between 6 and 20 mm. 87% success rate was achieved. The increased distance from the skin surface to the stone in those patients does not decrease the success rate provided the stone is positioned in the focal point or within 3 cm of it on the

[The effiectiveness of extracorporeal shock wave lithotripsy in treating proxima ureteral stones].

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Kogan, M I; Belousov, I I; Yassine, A M

2017-10-01

Extracorporeal shock wave lithotripsy (ESWL) has proven efficacy in the treatment of proximal ureteral stones. The research to date has not been able to establish real time to spontaneous stone clearance after ESWL and the appropriateness and effectiveness of -blockers in stimulating residual stone clearance after ESWL. To conduct a comprehensive assessment of the effectiveness of ESWL in treating proximal ureteral stones and determine the appropriateness of using -blockers to stimulate residual stone clearance. ESWL was performed in 40 patients with X-ray positive proximal ureteral stones. Before ESWL and at 3 months after the treatment all patients underwent multispiral computed tomography. ESWL was considered successful if there was a complete clearance of the stones with no residual fragments on the control MSCT. If a residual ureteral stone was found at 3 months after ESWL, a 2-week course of silodosin was administered. Complete stone clearance was achieved in 37.5% of patients. Silodosin therapy for residual stones resulted in stone clearance in 68.4% of cases. Taken together, ESWL monotherapy and additional 3 months of lithokinetic therapy resulted in stone clearance in 70.0% of patients. The remaining patients underwent contact ureteral lithotripsy. Spontaneous stone passage after ESWL for proximal ureteral stones occurs not in all patients. Most commonly it occurred during the first three weeks after ESWL, and thereafter stone passage was not observed. In half of the patients with residual stones they were asymptomatic. The effectiveness of ESWL as a monotherapy for ureteral stones greater than 15 mm is incomplete. Adding silodosin during the long-term post ESWL period improves the passage of asymptomatic residual stones in 2/3 of patients, which makes its use promising.

Apolipoprotein E4 genotype and gallbladder motility influence speed of gallstone clearance and risk of recurrence after extracorporeal shock-wave lithotripsy

NARCIS (Netherlands)

Portincasa, P.; van Erpecum, K. J.; van de Meeberg, P. C.; Dallinga-Thie, G. M.; de Bruin, T. W.; van Berge-Henegouwen, G. P.

1996-01-01

Extracorporeal shock-wave lithotripsy (ESWL) is an effective treatment in selected gallstone patients, but stone recurrence is a major drawback, Factors potentially influencing gallstone clearance and recurrence were studied in 84 patients in whom stone dissolution was diagnosed after ESWL plus bile

Extracorporeal shock wave lithotripsy for renal calculi, experience of first 100 cases at Jinnah Hospital, Lahore

International Nuclear Information System (INIS)

Nawaz, A.; Hussain, S.; Tahir, M.M.; Iqbal, N.

1999-01-01

Extracorporeal shock wave lithotripsy (ESWL), where available, has become the preferred treatment modality for majority of renal calculi. Nevertheless because of low morbidity and strong patient endorsement there is a natural tendency of over using it. We report the experience of first 100 patients of renal calculi treated at Lithotripsy Center, Jinnah Hospital, Lahore between November 1993 and October 1995.. All patients were treated on an out patients basis. In this prospective study patients were divided into three groups depending upon the initial stone size (Group 1 2.1 to 3 cm). Twenty-eight patients were lost to follow-up. Analysis of data revealed a success rate of 89.5%, 65.8% and 33.3% in Group-I, II and III respectively at the end of 3 months follow-up. Morbidity was directly procedures to stone burden, while success was inversely related to stone burden. Complications requiring auxiliary procedures were seen in none of the patients of Group-I while in 17.1% and 25% of the patients of Group-II and III respectively. Failure of the procedure demanding for an open intervention was seen in none of the patients of Group II and III respectively. We concluded that selection of patients is key to successful management of the renal calculi with ESWL. (author)

Treatment of mid- and lower ureteric calculi: extracorporeal shock-wave lithotripsy vs laser ureteroscopy. A comparison of costs, morbidity and effectiveness

NARCIS (Netherlands)

Bierkens, A. F.; Hendrikx, A. J.; de la Rosette, J. J.; Stultiens, G. N.; Beerlage, H. P.; Arends, A. J.; Debruyne, F. M.

1998-01-01

To determine the efficacy and costs of extracorporeal shock-wave lithotripsy (ESWL) compared with ureteroscopy (URS) in the treatment of mid- and lower ureteric calculi. The records of patients treated primarily by ESWL and URS were analysed retrospectively. Treatment with ESWL included 63 patients

Patient exposure and micronucleus assay during extracorporeal shock wave lithotripsy (ESWL) for kidney stones

International Nuclear Information System (INIS)

Shao, M.

1992-01-01

This study reports results of radiation exposure to 20 patients with kidney stones during Extracorporeal Shock Wave Lithotripsy (ESWL). A domestically made JT-ESWL-I Lithotripter was used. Data indicated that the amount of radiation exposure is related to the numbers, size, location and radiodensity of the stone, and also the number of shock wave and the time of fluoroscopy exposure given to the patients. The results of the micronucleus frequency of lymphocytes assay in the human peripheral blood are reported. This effect increased with increasing radiation exposure doses. (author). 4 refs., 2 tabs

[Bone and Calcium Research Update 2015. Clinical update of urolithiasis--ESWL (extracorporeal shock wave lithotripsy)].

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Iguchi, Taro; Nakatani, Tatsuya

2015-01-01

ESWL (extracorporeal shock wave lithotripsy) is widely used for upper urinary stones and successfully treats most patients with uncomplicated kidney stones. ESWL is still of high strategic importance despite ureteroscopy and PNL occupy an essential place in the treatment of urinary stones by technologic advancements. However ESWL is just one of treatment tool and the best procedure should be selected for the patients. Moreover urolithiasis is one of lifestyle-related diseases and should be treated as systemic illness in the daily medical practice.

An FDTD-based computer simulation platform for shock wave propagation in electrohydraulic lithotripsy.

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Yılmaz, Bülent; Çiftçi, Emre

2013-06-01

Extracorporeal Shock Wave Lithotripsy (ESWL) is based on disintegration of the kidney stone by delivering high-energy shock waves that are created outside the body and transmitted through the skin and body tissues. Nowadays high-energy shock waves are also used in orthopedic operations and investigated to be used in the treatment of myocardial infarction and cancer. Because of these new application areas novel lithotriptor designs are needed for different kinds of treatment strategies. In this study our aim was to develop a versatile computer simulation environment which would give the device designers working on various medical applications that use shock wave principle a substantial amount of flexibility while testing the effects of new parameters such as reflector size, material properties of the medium, water temperature, and different clinical scenarios. For this purpose, we created a finite-difference time-domain (FDTD)-based computational model in which most of the physical system parameters were defined as an input and/or as a variable in the simulations. We constructed a realistic computational model of a commercial electrohydraulic lithotriptor and optimized our simulation program using the results that were obtained by the manufacturer in an experimental setup. We, then, compared the simulation results with the results from an experimental setup in which oxygen level in water was varied. Finally, we studied the effects of changing the input parameters like ellipsoid size and material, temperature change in the wave propagation media, and shock wave source point misalignment. The simulation results were consistent with the experimental results and expected effects of variation in physical parameters of the system. The results of this study encourage further investigation and provide adequate evidence that the numerical modeling of a shock wave therapy system is feasible and can provide a practical means to test novel ideas in new device design procedures

Treatment of cystine stones: combined approach using open pyelolithotomy, percutaneous pyelolithotripsy, extracorporeal shock wave lithotripsy and chemolysis

DEFF Research Database (Denmark)

Aabech, J; Andersen, J T

1993-01-01

Treatment of cystine stones in the urinary tract can be difficult because of a high frequency of recurrence, resistance to Extracorporeal Shock Wave Lithotripsy (ESWL), difficulty in localization and access to peripheral stones during Percutaneous Nephrolithotripsy (PCNL), and the insufficient...... effect of oral chemolysis. We present two cases of urinary cystine calculi treated with a combination of pyelolithotomy, PCNL, ESWL and percutaneous irrigation chemolysis, using N-acetylcysteine and Tromethamine-E....

Drugs for Pain Management in Shock Wave Lithotripsy

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Christian Bach

2011-01-01

Full Text Available Objective. With this review, we provide a comprehensive overview of the main aspects and currently used drugs for analgesia in shockwave lithotripsy. Evidence Acquisition. We reviewed current literature, concentrating on newer articles and high-quality reviews in international journals. Results. No standardized protocols for pain control in SWL exist, although it is crucial for treatment outcome. General and spinal anaesthesia show excellent pain control but are only recommended for selected cases. The newer opioids and nonsteroidal anti-inflammatory drugs are able to deliver good analgesia. Interest in inhalation anaesthesia with nitrous oxide, local anaesthesia with deep infiltration of the tissue, and dermal anaesthesia with EMLA or DMSO has recently rekindled, showing good results in terms of pain control and a favourable side effect profile. Tamsulosin and paracetamol are further well-known drugs being currently investigated. Conclusion. Apart from classically used drugs like opioids and NSARs, medicaments like nitrous oxide, paracetamol, DMSA, or refined administration techniques for infiltration anaesthesia show a good effectiveness in pain control for SWL.

Abdominal fat distribution on computed tomography predicts ureteric calculus fragmentation by shock wave lithotripsy.

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Juan, Hsu-Cheng; Lin, Hung-Yu; Chou, Yii-Her; Yang, Yi-Hsin; Shih, Paul Ming-Chen; Chuang, Shu-Mien; Shen, Jung-Tsung; Juan, Yung-Shun

2012-08-01

To assess the effects of abdominal fat on shock wave lithotripsy (SWL). We used pre-SWL unenhanced computed tomography (CT) to evaluate the impact of abdominal fat distribution and calculus characteristics on the outcome of SWL. One hundred and eighty-five patients with a solitary ureteric calculus treated with SWL were retrospectively reviewed. Each patient underwent unenhanced CT within 1 month before SWL treatment. Treatment outcomes were evaluated 1 month later. Unenhanced CT parameters, including calculus surface area, Hounsfield unit (HU) density, abdominal fat area and skin to calculus distance (SSD) were analysed. One hundred and twenty-eight of the 185 patients were found to be calculus-free following treatment. HU density, total fat area, visceral fat area and SSD were identified as significant variables on multivariate logistic regression analysis. The receiver-operating characteristic analyses showed that total fat area, para/perirenal fat area and visceral fat area were sensitive predictors of SWL outcomes. This study revealed that higher quantities of abdominal fat, especially visceral fat, are associated with a lower calculus-free rate following SWL treatment. Unenhanced CT is a convenient technique for diagnosing the presence of a calculus, assessing the intra-abdominal fat distribution and thereby helping to predict the outcome of SWL. • Unenhanced CT is now widely used to assess ureteric calculi. • The same CT protocol can provide measurements of abdominal fat distribution. • Ureteric calculi are usually treated by shock wave lithotripsy (SWL). • Greater intra-abdominal fat stores are generally associated with poorer SWL results.

Experience of extracorporeal shock wave lithotripsy for kidney and upper ureteric stones by electromagnetic lithotripter

International Nuclear Information System (INIS)

Wazir, B.G.; Haq, M.I.H.; Faheem-ul-Haq; Nawaz, A.; Nawaz, A.; Ikramullah; Jamil, M.

2010-01-01

Background: Extracorporeal Shock Wave Lithotripsy (ESWL) is a non-invasive treatment of urinary stones which breaks them, by using externally applied, focused, high intensity acoustic pulse, into smaller pieces so that they can pass easily through ureter. Shock wave generation, focusing, coupling and stone localisation by fluoroscope or ultrasound are the basic components of ESWL. ESWL has some complications and is contraindicated in certain situations. The aim of this study was to evaluate the effectiveness and safety of ESWL in kidney and upper ureteric stones by Electromagnetic Lithotriptor. Methods: All adult patients with renal and upper ureteric stones having a diameter of up to 1 Cm were included in the study. Basic evaluation such as history, examination, ultrasound and excretory urography were performed. Electromagnetic lithotripsy was done and data were collected on a printed proforma from January 1, 2008 to March 30, 2009 in Institute of Kidney Diseases, Peshawar. Results: Out of a total of 625 patients 463 were male and 162 were female; 67.36% of patients were having renal stones, 23.84% upper ureteric and 8.8% both renal and ureteric stones. Complications noted were renal colic in 9.76%, haematuria in 3.2%, stein strasse in 2.72%, and fever in 1.12% of patients. The stone free rate was 89% and 7% of patients were having stone fragments <4 mm. ESWL failed in 4% of patients. Conclusion: ESWL is a safe and effective way of treating kidney and upper ureteric stones. (author)

Evaluation of the dose to patients during extracorporated lithotripsy treatment (ESWL)

International Nuclear Information System (INIS)

Rodriguez, M.F.; Roman, J.R.

1997-01-01

Litiasis urinaria is appearing more frequently with approximately 12% of the population with a stone in the urinary system at any moment of their life. The stone produces severe colics causing pain in the transit through the ureter. This is probably one of the worst pains and experiences in human beings. The treatment by extracorporated lithotripsy consists of powdering or smashing into pieces the stones in the kidney and ureter. This has been done with the help of shock waves generated from a canon and which are focused on the stone. The machine used is aimed and the procedure is monitored by way of X rays. The high number of patients treated per year and the doses applied to the patients during the diagnosis, treatment and follow-up led to this study

Successful evacuation of large perirenal hematoma after extracorporeal shock wave lithotripsy (ESWL) - step 1 of the IDEAL recommendations of surgical innovation.

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Hallmann, Steffen; Petersein, Jan; Ruttloff, Jürgen; Ecke, Thorsten H

2017-02-01

Larger perirenal hematomas after extracorporeal shock wave lithotripsy (ESWL) are sometimes related to the loss of renal function due to compression of the normal renal tissue. After computed tomography-guided drainage and locally applied urokinase, the hematoma was fractionally evacuated. This procedure is a save and fast way to recover normal renal function.

Medical malpractice in endourology: analysis of closed cases from the State of New York.

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Duty, Brian; Okhunov, Zhamshid; Okeke, Zeph; Smith, Arthur

2012-02-01

Medical malpractice indemnity payments continue to rise, resulting in increased insurance premiums. We reviewed closed malpractice claims pertaining to endourological procedures with the goal of helping urologists mitigate their risk of lawsuit. All closed malpractice claims from 2005 to 2010 pertaining to endourological procedures filed against urologists insured by the Medical Liability Mutual Insurance Company of New York were examined. Claims were reviewed for plaintiff demographics, medical history, operative details, alleged complication, clinical outcome and lawsuit disposition. A total of 25 closed claims involved endourological operations and of these cases 10 were closed with an indemnity payment. The average payout was $346,722 (range $25,000 to $995,000). Of the plaintiffs 16 were women and mean plaintiff age was 51.4 years. Cystoscopy with ureteral stent placement/exchange resulted in 13 lawsuits, ureteroscopic lithotripsy 8, percutaneous stone extraction 2 and shock wave lithotripsy 2. There were 17 malpractice suits brought for alleged operative complications. Failure to arrange adequate followup was implicated in 4 cases. Error in diagnosis and delay in treatment was alleged in 3 claims. Urologists are not immune to the current medical malpractice crisis. Endourology and urological oncology generate the greatest number of lawsuits against urologists. Most malpractice claims involving endourological procedures result from urolithiasis and alleged technical errors. Therefore, careful attention to surgical technique is essential during stone procedures to reduce the risk of malpractice litigation. Copyright © 2012 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Bilateral complete ureteral duplication with calculi obstructing both limbs of left double ureter.

Science.gov (United States)

Aiken, William D; Johnson, Peter B; Mayhew, Richard G

2015-01-01

A woman with bilateral complete ureteral duplication with stones simultaneously obstructing both limbs of the left double ureter is presented. A search of the English medical literature suggests that this is the first reported case. Based on the initial difficulty accessing the stones via ureteroscopy we make recommendations regarding how this rare problem should be approached if encountered. A 37-year old woman with left-sided flank pain was discovered on CT scan to have bilateral complete ureteral duplication and three stones obstructing both limbs of the left double ureter. Ureteroscopy was initially unsuccessful due to the very small calibre and unyielding nature of the ureters and both ureteral limbs were stented. Repeat ureteroscopy was easily achieved after pre-stenting and the impacted stones were completely cleared with intracorporeal laser lithotripsy. The smaller calibre of both double ureters and their presence in a common adventitial sheath distally, made initial attempts at ureteroscopy difficult. Stenting both limbs increased ureteral compliance, passively dilated both ureters and allowed for improved manoeuvrability and retrograde passage of the ureteroscope. Based on the experience with this first reported case it is recommended that pre-stenting should be routinely performed prior to any attempt at ureteroscopy in cases of stones complicating completely duplicated ureters. We report the first recorded case of bilateral complete ureteral duplication with stones simultaneously obstructing both limbs of the double ureter and recommend that routine pre-stenting be done prior to ureteroscopy to allow easy uncomplicated retrograde passage of the ureteroscope. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

Outcome of a session of extracorporeal shock wave lithotripsy before endoscopic retrograde cholangiopancreatography for problematic and large common bile duct stones

Science.gov (United States)

Tao, Tao; Zhang, Ming; Zhang, Qi-Jie; Li, Liang; Li, Tao; Zhu, Xiao; Li, Ming-Dong; Li, Gui-Hua; Sun, Shu-Xia

2017-01-01

AIM To compare the efficacy of a session of extracorporeal shock wave lithotripsy (ESWL) before endoscopic retrograde cholangiopancreatography (ERCP) vs ERCP only for problematic and large common bile duct (CBD) stones. METHODS Adult patients with CBD stones for whom initial ERCP was unsuccessful because of the large size of CBD stones were identified. The patients were randomized into two groups, an “ESWL + ERCP group” and an “ERCP-only” group. For ESWL + ERCP cases, ESWL was performed prior to ERCP. Clearance of the CBD, complications related to the ESWL/ERCP procedure, frequency of mechanical lithotripsy use and duration of the ERCP procedure were evaluated in both groups. RESULTS There was no significant difference in baseline characteristics between the two groups. A session of ESWL before ERCP compared with ERCP only resulted in similar outcomes in terms of successful stone removal within the first treatment session (74.2% vs 71.0%, P = 0.135), but a higher clearance rate within the second treatment session (84.4% vs 51.6%, P = 0.018) and total stone clearance (96.0% vs 86.0%, P = 0.029). Moreover, ESWL prior to ERCP not only reduced ERCP procedure time (43 ± 21 min vs 59 ± 28 min, P = 0.034) and the rate of mechanical lithotripsy use (20% vs 30%, P = 0.025), but also raised the clearance rate of extremely large stones (80.0% vs 40.0%, P = 0.016). Post-ERCP complications were similar for the two groups. CONCLUSION Based on the higher rate of successful stone removal and minimal complications, ESWL prior to ERCP appears to be a safe and effective treatment for the endoscopic removal of problematic and large CBD stones. PMID:28785149

Extracorporeal shock wave lithotripsy of intrahepatic stones with piezoelectric lithotriptor: in vitro study

International Nuclear Information System (INIS)

Choi, Byung Ihn; Yoon, Chong Hyun; Park, Yong Hyun; Han, Joon Koo; Yoon, Yong Bum; Shin, Yong Moon; Kim, Jin Q; Kim, Chu Wan; Han, Man Chung

1992-01-01

This study was designed to investigate effectiveness of fragmentation during lithotripsy using 103 intrahepatic stones collected from 10 patients, who had previously undergone biliary surgery. The size of each stone was measured and sonography was performed for the evaluation of the sonographic type of the stones. In vitro lithotripsy was performed on individual stones using piezoelectric lithotriptor to evaluate the fragmentation rate and average number of shock waves for fragmentation. Chemical analysis of each stone was done to determine chemical composition including calcium, bilirubin, and cholesterol. The size of the stones was from 5 mm to 20 mm in diameter. Sonographic type I (echo of whole stone with posterior acoustic shadow) was 68, and type II (are-like strong surface echo of stone with clear posterior acoustic shadow) was 35 in number. The majority (78%) of stones in group I (5-9 mm in diameter) showed sonographic type I characteristics, and 62% of stones in group 3 (larger than 15 mm in diameter) showed sonographic type II characteristics. There was a positive correlation between the size and sonographic type of stones. Fragmentation rates of stones were 100% in group I, 71.9% in group 2 (10-15 mm in diameter), 43.8% in group 3, respectively. Fragmentation rates of stones with sonographic type I and II were 91.2%, 65.7%, respectively. The average number of shock waves for partial and complete fragmentation was 2753 ± 4937 and 6219 ± 10133, respectively. There was a positive correlation between the number of shock waves for fragmentation and diameter of stones (r = 0.618, ρ < 0.05). There was no correlation between the number of shock waves for fragmentation and chemical composition of stones. In conclusion, the most important variable determining the degree of fragmentation of intrahepatic stones using ESWL is not their chemical composition but their size and sonographic characteristics

Extracorporeal shock wave lithotripsy of intrahepatic stones with piezoelectric lithotriptor: in vitro study

Energy Technology Data Exchange (ETDEWEB)

Choi, Byung Ihn; Yoon, Chong Hyun; Park, Yong Hyun; Han, Joon Koo; Yoon, Yong Bum; Shin, Yong Moon; Kim, Jin Q; Kim, Chu Wan; Han, Man Chung [Seoul National University, College of Medicine, Seoul (Korea, Republic of)

1992-05-15

This study was designed to investigate effectiveness of fragmentation during lithotripsy using 103 intrahepatic stones collected from 10 patients, who had previously undergone biliary surgery. The size of each stone was measured and sonography was performed for the evaluation of the sonographic type of the stones. In vitro lithotripsy was performed on individual stones using piezoelectric lithotriptor to evaluate the fragmentation rate and average number of shock waves for fragmentation. Chemical analysis of each stone was done to determine chemical composition including calcium, bilirubin, and cholesterol. The size of the stones was from 5 mm to 20 mm in diameter. Sonographic type I (echo of whole stone with posterior acoustic shadow) was 68, and type II (are-like strong surface echo of stone with clear posterior acoustic shadow) was 35 in number. The majority (78%) of stones in group I (5-9 mm in diameter) showed sonographic type I characteristics, and 62% of stones in group 3 (larger than 15 mm in diameter) showed sonographic type II characteristics. There was a positive correlation between the size and sonographic type of stones. Fragmentation rates of stones were 100% in group I, 71.9% in group 2 (10-15 mm in diameter), 43.8% in group 3, respectively. Fragmentation rates of stones with sonographic type I and II were 91.2%, 65.7%, respectively. The average number of shock waves for partial and complete fragmentation was 2753 {+-} 4937 and 6219 {+-} 10133, respectively. There was a positive correlation between the number of shock waves for fragmentation and diameter of stones (r = 0.618, {rho} < 0.05). There was no correlation between the number of shock waves for fragmentation and chemical composition of stones. In conclusion, the most important variable determining the degree of fragmentation of intrahepatic stones using ESWL is not their chemical composition but their size and sonographic characteristics.

Impact of renal anatomy on shock wave lithotripsy outcomes for lower pole kidney stones: results of a prospective multifactorial analysis controlled by computerized tomography.

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Torricelli, Fabio C M; Marchini, Giovanni S; Yamauchi, Fernando I; Danilovic, Alexandre; Vicentini, Fabio C; Srougi, Miguel; Monga, Manoj; Mazzucchi, Eduardo

2015-06-01

We evaluated which variables impact fragmentation and clearance of lower pole calculi after shock wave lithotripsy. We prospectively evaluated patients undergoing shock wave lithotripsy for a solitary 5 to 20 mm lower pole kidney stone between June 2012 and August 2014. Patient body mass index and abdominal waist circumference were recorded. One radiologist blinded to shock wave lithotripsy outcomes measured stone size, area and density, stone-to-skin distance, infundibular length, width and height, and infundibulopelvic angle based on baseline noncontrast computerized tomography. Fragmentation, success (defined as residual fragments less than 4 mm in asymptomatic patients) and the stone-free rate were evaluated by noncontrast computerized tomography 12 weeks postoperatively. Univariate and multivariate analysis was performed. A total of 100 patients were enrolled in the study. Mean stone size was 9.1 mm. Overall fragmentation, success and stone-free rates were 76%, 54% and 37%, respectively. On logistic regression body mass index (OR 1.27, 95% CI 1.11-1.49, p = 0.004) and stone density (OR 1.0026, 95% CI 1.0008-1.0046, p = 0.005) significantly impacted fragmentation. Stone size (OR 1.24, 95% CI 1.07-1.48, p = 0.039) and stone density (OR 1.0021, 95% CI 1.0007-1.0037, p = 0.012) impacted the success rate while stone size (OR 1.24, 95% CI 1.04-1.50, p = 0.029), stone density (OR 1.0015, 95% CI 1.0001-1.0032, p = 0.046) and infundibular length (OR 1.1035, 95% CI 1.015-1.217, p = 0.015) impacted the stone-free rate. The best outcomes were found in patients with a body mass index of 30 kg/m(2) or less, stones 10 mm or less and 900 HU or less, and an infundibular length of 25 mm or less. The coexistence of significant unfavorable variables led to a stone-free rate of less than 20%. Obese patients with higher than 10 mm density stones (greater than 900 HU) in the lower pole of the kidney with an infundibular length of greater than 25 mm should be discouraged from

Quantification of the Range of Motion of Kidney and Ureteral Stones During Shockwave Lithotripsy in Conscious Patients.

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Harrogate, Suzanne R; Yick, L M Shirley; Williams, James C; Cleveland, Robin O; Turney, Benjamin W

2016-04-01

Effective shockwave lithotripsy requires accurate targeting of the stone throughout the course of treatment. Stone movement secondary to respiratory movement can make this more difficult. In vitro work has shown that stone motion outside the focal region reduces the efficacy of stone fragmentation; however, there are few clinical data on the degree of stone movement in patients during treatment. To investigate this, X-ray fluoroscopic images of the kidney and ureteral stones at the upper and lower limits of the normal respiratory cycle were acquired during shock wave lithotripsy of 58 conscious patients, and stone excursion was calculated from these images. In addition, the respiration rate and patient perceived pain were recorded during the course of the treatment. It was found that stone motion secondary to respiration was 7.7 ± 2.9 mm for kidney stones and 3.6 ± 2.1 mm for ureteral stones-less than has been reported in studies with anesthetized patients. There was no significant change of motion over the course of treatment although pain was found to increase. These data suggest that stone motion in conscious patients is less than in anesthetized patients. Furthermore, it suggests that lithotripters with focal regions of 8 mm or greater should not suffer from a marked drop in fragmentation efficiency due to stone motion.

Extracorporeal shock wave lithotripsy in the treatment of pediatric urolithiasis: a single institution experience

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Konstantinos N. Stamatiou

2010-12-01

Full Text Available PURPOSE: To compare the efficacy and safety of the electromagnetic lithotripter in the treatment of pediatric lithiasis to that of the earlier electrohydraulic model. MATERIALS AND METHODS: Two groups of children with lithiasis aged between 10 and 180 months who underwent extracorporeal shock wave lithotripsy (ESWL. In the first group (26 children, ESWL was performed by using the electrohydraulic MPL 9000X Dornier lithotripter between 1994 and 2003 while in the second group (19 children the electromagnetic EMSE 220 F-XP Dornier lithotripter was used from April 2003 to May 2006. RESULTS: In the first group, 21/26 children (80.7% were stone free at first ESWL session. Colic pain resolved by administration of an oral analgesic in 6 (23%, brief hematuria (< 24 h resolved with increased fluid intake in 5 (19.2%, while slightly elevated body temperature (< 38°C occurred in 4 (15.3%. Four children (15.3% failed to respond to treatment and were treated with ureteroscopy. In the second group 18/19 children were completely stone free at first ESWL session (94.7%. Complications were infrequent and of minor importance: colic pain treated with oral analgesic occurred in 1 (5.26%, brief hematuria (< 24 h, resolved with increased fluid intake in 4 (21% and slightly elevated body temperature (< 38°C monitored for 48 hours occurred in 6 (31.5%. Statistical analysis showed that electromagnetic lithotripter is more efficacious and safer than the earlier electrohydraulic model. CONCLUSIONS: Technological development not only has increased efficacy and safety of lithotripter devices in treating pediatric lithiasis, but it also provided less painful lithotripsy by eliminating the need for general anesthesia.

New ultrasound stone locking system in extracorporeal lithotripsy: Decreased duration of fluoroscopy and radiation doses

International Nuclear Information System (INIS)

Abid, N.; Ravier, E.; Codas, R.; Crouzet, S.; Martin, X.

2013-01-01

Extracorporeal shock wave lithotripsy is the most common method of treatment for kidney stones. Both fluoroscopy and ultrasound imaging can be used to locate stones, but fluoroscopy is more frequently employed. Evaluation of a new stereotaxic navigational system: the stone was located using an ultrasound probe, and its 3D location was saved. The table automatically moved to position the stone at the focal point. A real-time follow-up was possible during treatment. Our objective was to demonstrate a decrease in the use of fluoroscopy to locate kidney stones for extracorporeal shock wave lithotripsy through the use of a 3D ultrasound stone locking system. Prospective analysis of the case records of the 20 patients preceding and the 20 patients succeeding the arrival of the ultrasound stone locking system Visio-Track (EDAP-TMS). We used a Student test to compare age, BMI, kidney stone size, number of shock waves and administered energy. Patient characteristics were comparable. The average age was 55 years old and the average kidney stone size was 10.7 mm. Radiation duration was 174.8 seconds in the group without Visio-Track versus 57.1 seconds in the group with it (P < 0.0001). A similar result was observed for radiation doses: 5197.25 mGy.cm 2 for the group without versus 1987.6 mGy.cm 2 for the group with Visio-Track (P ≡ 0.0033). The stone locking system Visio-Track reduced fluoroscopy in our first group of patients, which decreased the patient's individual absorbed irradiation dose. (authors)

The new Olympus digital flexible ureteroscope (URF-V: Initial experience

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Saeed M Al-Qahtani

2011-01-01

Conclusion: New ODF-URS (URF-V is a reliable and durable device, with a good success rate and improved functional parameters. It is a superior device compared to predecessor generations of conventional fiberoptic endoscopes for the light source and the image quality; however, randomized comparative studies are necessary to evaluate performances and durability of this device.

EXTRACORPOREAL SHOCK WAVE LITHOTRIPSY IN TREATMENT OF PEDIATRIC UROLITHIASIS

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Emilija Golubovic

2006-04-01

Full Text Available The paper presents the experiences in the treatment of urinary tract calculosis in 114 children aged 6 months to 14 years by means of extracorporeal shock wave lithotripsy (ESWL.The treatment was performed at the Institute of Radiology and the Clinic for Pediatric Surgery and Orthopedics in Nis, in the period 1988-2000 on Siemens Litostar lithotriptor. The children were treated after clinical, laboratory and radiological preparation, provided that the stone was not greater than 3 cm (measured in native urinary tract graph and that it was not located in the pelvic part of the ureter. In the present study, the success in application of ESWL for treating pediatric patients was 88%. The total clearance of fragments was found in 57% of patients, whereas retention of fragments smaller than 4 mm three months after the last treatment was present in 31% of patients. ESWL treatment failed in 12% of patients since they had retained fragments greater than 4 mm.The authors recommend this method as a method of choice in the treatment of renal and urethral calculi in children.

MICROBIOTA URINE BEFORE AND AFTER LITHOTRIPSY FOR RENAL STONES

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Y. L. Naboka

2013-01-01

Full Text Available Extracorporeal shock wave lithotripsy (ESWL in spite of the low invasiveness and high efficiency is accompanied by an infectious- inflammatory complications and renal parenchymal injury . Dynamics of microbial spectrum urine and the impact of postoperative antibiotic therapy currently remains unexplored. The study included 30 patients subjected to ESWL. Bacteriological study was midstream morning urine before ESWL, 1, 3 days after ESWL, and midstream urine in the first urination after ESWL. All patients were divided into 2 groups. Group I consisted of patients (46.7% with antibiotic therapy . Group II patients (53.3 % antibiotic therapy was performed. In most cases (97.8 % were bacteriuria , while in 75% of cases highlighted in the various options bacterial associations representation aerobic- anaerobic mixed infection, among which was dominated by non-clostridial anaerobic bacteria in all samples. Revealed that after ESWL microbial spectrum urine does not change in any case within 3 days , except for Enterobacteriaceae, but the frequency of occurrence and level of bacteriuria vary for different periods after surgery and fees or absence of antibiotic therapy.

Extracorporeal shock wave lithotripsy for renal stone with infundibular stenosis

International Nuclear Information System (INIS)

Lee, Won Hong; Son, Soon Yong; Kang, Seong Ho; Lee, Yong Moon; Yoon, Seok Hwan

2006-01-01

We analyzed retrospectively our experience to evaluate an effect of extracorporeal shock wave lithotripsy (ESWL) for renal stone with infundibular stenosis. From January 2002 to August 2005, 35 patients with renal stone with infundibular stenosis were treated with ESWL. The diagnosis of infundibular stenosis was made by intravenous pyelography or retrograde pyelography. The final follow-up check was performed by simple abdominal film or computed tomography and interview after 6 months to 24 months (mean 10 months). 7 (20.0%) of 35 patients was freed completely, but Stone free rate including less than 2 mm size was 80% (28/35). 30 (85.7%) patients became asymptomatic, 4 (11.4%) patients were continued, and 1 (2.9%) patient was required the percutaneous nephrostolithotomy. Although ESWL has a low complete stone free rate, We suggest that renal stone with infundibular stenosis should be treated with ESWL, because that is likely to produce a high symptom free and low complications

Extracorporeal shock wave lithotripsy for renal stone with infundibular stenosis

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Lee, Won Hong; Son, Soon Yong; Kang, Seong Ho; Lee, Yong Moon [Asan Medical Center, Seoul (Korea, Republic of); Yoon, Seok Hwan [Dongnam Health College, Suwon (Korea, Republic of)

2006-06-15

We analyzed retrospectively our experience to evaluate an effect of extracorporeal shock wave lithotripsy (ESWL) for renal stone with infundibular stenosis. From January 2002 to August 2005, 35 patients with renal stone with infundibular stenosis were treated with ESWL. The diagnosis of infundibular stenosis was made by intravenous pyelography or retrograde pyelography. The final follow-up check was performed by simple abdominal film or computed tomography and interview after 6 months to 24 months (mean 10 months). 7 (20.0%) of 35 patients was freed completely, but Stone free rate including less than 2 mm size was 80% (28/35). 30 (85.7%) patients became asymptomatic, 4 (11.4%) patients were continued, and 1 (2.9%) patient was required the percutaneous nephrostolithotomy. Although ESWL has a low complete stone free rate, We suggest that renal stone with infundibular stenosis should be treated with ESWL, because that is likely to produce a high symptom free and low complications.

Sound field prediction of ultrasonic lithotripsy in water with spheroidal beam equations

International Nuclear Information System (INIS)

Zhang Lue; Wang Xiang-Da; Liu Xiao-Zhou; Gong Xiu-Fen

2015-01-01

With converged shock wave, extracorporeal shock wave lithotripsy (ESWL) has become a preferable way to crush human calculi because of its advantages of efficiency and non-intrusion. Nonlinear spheroidal beam equations (SBE) are employed to illustrate the acoustic wave propagation for transducers with a wide aperture angle. To predict the acoustic field distribution precisely, boundary conditions are obtained for the SBE model of the monochromatic wave when the source is located on the focus of an ESWL transducer. Numerical results of the monochromatic wave propagation in water are analyzed and the influences of half-angle, fundamental frequency, and initial pressure are investigated. According to our results, with optimization of these factors, the pressure focal gain of ESWL can be enhanced and the effectiveness of treatment can be improved. (paper)

Radiologic contribution to the extracorporeal lithotripsy treatment of calyceal diverticular calculi

International Nuclear Information System (INIS)

Papanicolaou, N.; Pfister, R.C.; Stafford, S.A.

1987-01-01

The authors reviewed the radiologic studies in 19 patients with calyceal diverticular calculi treated with extracorporeal lithotripsy (EL) in order to establish criteria predicting successful outcome. Pre-EL imaging was performed to evaluate the size of calculus in relation to the diverticular cavity, and the width of the connection of the diverticulum to the adjacent calyx. Post-EL studies were performed to assess fragmentation and passage of fragments. EL fragmented calculi in 15 diverticula with cavities larger than stone volume. Complete passage of fragments was shown in five patients and partial passage in two, all with wide diverticular necks. No passage was seen in eight diverticular with fragmented calculi, five of which had narrow or nondemonstrable necks. The radiologic demonstration of large diverticular correlates well with effective EL fragmentation, and a wide neck results in satisfactory fragment passage. Calculi in tight, narrowly communicating diverticula are unlikely to respond to EL

Successful extracorporeal shock wave lithotripsy (ESWL) treatment of a symptomatic massive biliary stone proximal to an anastomotic biliary stricture.

Science.gov (United States)

Muratori, Rosangela; Mandolesi, Daniele; Galaverni, Maria Cristina; Azzaroli, Francesco

2017-06-01

Postoperative benign biliary stricture in the anastomotic site is one of the most common complications of biliary-enteric anastomosis, with a rate of 6.87% after 2-13 years of follow-up. If untreated, biliary strictures can induce other complications such as recurrent cholangitis, intrahepatic stones, pancreatitis and secondary biliary cirrhosis. We report our experience with extracorporeal shock wave lithotripsy (ESWL) in a patient with a massive symptomatic stone proximal to an anastomotic biliary stricture.

The effect of extracorporeal shock wave lithotripsy in the management of idiopathic gallstones in children

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Mousavi, Seyed Abdollah; Karami, Hasan; Barzegarnejad, Ayub

2014-01-01

Objective: The most common etiology for gallstones in children is hemolytic diseases; however, the prevalence of nonhemolytic gallstones, which are mostly idiopathic, is increasing. Several studies concerning the treatment of gallstones with respect to the influence of extracorporeal shock wave lithotripsy (ESWL) have been conducted in adults, but not to the same extent in children. Therefore, this study attempted to examine the effects of lithotripsy on idiopathic gallstones in children. Materials and Methods: In this study, 12 children, all of whom were under 12 years of age and diagnosed with idiopathic gallstones, were treated with ESWL. The average age of the children examined in this study was 6.5 years (range 3-11 years). Patients were treated with 2500-3000 shockwaves per session. The number of shockwaves was 90 shocks/min and the impulse intensity ranged from 10 to 12 kV. The final goal was the fragmentation of stones in pieces with less than 3 mm in dimension. Patients were followed up for 6-30 months. Results: A total of 12 patients were treated with ESWL for 14 rounds. In three patients, complete fragmentation occurred within the first trial and was cleared. The nine remaining patients underwent ESWL 10 times in which an acceptable change in the gallstone's condition was not observed. Five of the patients underwent surgery. The chemical composition of the gallstones showed that the dominant element in them was calcium. Conclusions: Our findings show that performing ESWL can be effective in some children. Further studies with larger population are recommended. Furthermore, it seems increasing the voltage intensity and frequency as conducted in adults accompanied with biliary acids prescription can be effective in children. PMID:25336804

Detection and Evaluation of Renal Injury in Burst Wave Lithotripsy Using Ultrasound and Magnetic Resonance Imaging.

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May, Philip C; Kreider, Wayne; Maxwell, Adam D; Wang, Yak-Nam; Cunitz, Bryan W; Blomgren, Philip M; Johnson, Cynthia D; Park, Joshua S H; Bailey, Michael R; Lee, Donghoon; Harper, Jonathan D; Sorensen, Mathew D

2017-08-01

Burst wave lithotripsy (BWL) is a transcutaneous technique with potential to safely and effectively fragment renal stones. Preclinical investigations of BWL require the assessment of potential renal injury. This study evaluates the capabilities of real-time ultrasound and MRI to detect and evaluate BWL injury that was induced in porcine kidneys. Ten kidneys from five female farm pigs were treated with either a 170 or 335 kHz BWL transducer using variable treatment parameters and monitored in real-time with ultrasound. Eight kidneys were perfusion fixed and scanned with a 3-Tesla MRI scanner (T1-weighted, T2-weighted, and susceptibility-weighted imaging), followed by processing via an established histomorphometric technique for injury quantification. In addition, two kidneys were separately evaluated for histologic characterization of injury quality. Observed B-mode hyperechoes on ultrasound consistent with cavitation predicted the presence of BWL-induced renal injury with a sensitivity and specificity of 100% in comparison to the histomorphometric technique. Similarly, MRI detected renal injury with a sensitivity of 90% and specificity of 100% and was able to identify the scale of lesion volumes. The injuries purposefully generated with BWL were histologically similar to those formed by shock wave lithotripsy. BWL-induced renal injury can be detected with a high degree of sensitivity and specificity by real-time ultrasound and post-treatment ex vivo MRI. No injury occurred in this study without cavitation detected on ultrasound. Such capabilities for injury detection and lesion volume quantification on MRI can be used for preclinical testing of BWL.

Extracorporeal shock-wave lithotripsy of bile duct stones

International Nuclear Information System (INIS)

Lee, Jong Tae; Kim, Myung Joon; Yoo, Hyung Sik; Suh, Jung Ho; Lee, Moo Sang; Jo, Jang Hwan; Kim, Byung Ro

1989-01-01

During the past one and half year, we performed ESWL therapy in 13 patients with common bile duct and intrahepatic duct stones, applying Lithostar-R (Siemens co. West Germany) and analyzed their results. In 13 patients, 9 residual common bile duct stones and 7 intrahepatic duct stones were selected postoperatively. The size of stones were ranged from 0.7 cm to 3.5 cm in diameter. 2 stones were multiple and the remained 14 were single in number. The visualization of stones were done with fluoroscopy after the injection of contrast media via cholangiographic T-tube or ERCP. ESWL were applied continuously until stone disintegration was visible, or upto maximum number of 3500 discharge of shock wave. If not disintegrated upto 3500, patients were underwent second or third lithotripsy session with interval of one week. Our results showed that among 9 common bile duct stones, 4 were completely disintegrated and passed out spontaneously, but 3 partially fragmented and removed by the additional procedure. 2 were failed. Among 7 intrahepatic stones, 3 completely and 2 partially were succeeded. One stone partially fragmented were retained without removal and other one were failed. Skin petechia in all patients were revealed on the entry port of shock wave, but no serous complication was not occurred

Tandem shock wave cavitation enhancement for extracorporeal lithotripsy

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Loske, Achim M.; Prieto, Fernando E.; Fernández, Francisco; van Cauwelaert, Javier

2002-11-01

Extracorporeal shock wave lithotripsy (ESWL) has been successful for more than twenty years in treating patients with kidney stones. Hundreds of underwater shock waves are generated outside the patient's body and focused on the kidney stone. Stones fracture mainly due to spalling, cavitation and layer separation. Cavitation bubbles are produced in the vicinity of the stone by the tensile phase of each shock wave. Bubbles expand, stabilize and finally collapse violently, creating stone-damaging secondary shock waves and microjets. Bubble collapse can be intensified by sending a second shock wave a few hundred microseconds after the first. A novel method of generating two piezoelectrically generated shock waves with an adjustable time delay between 50 and 950 µs is described and tested. The objective is to enhance cavitation-induced damage to kidney stones during ESWL in order to reduce treatment time. In vitro kidney stone model fragmentation efficiency and pressure measurements were compared with those for a standard ESWL system. Results indicate that fragmentation efficiency was significantly enhanced at a shock wave delay of about 400 and 250 µs using rectangular and spherical stone phantoms, respectively. The system presented here could be installed in clinical devices at relatively low cost, without the need for a second shock wave generator.

Extracorporeal shock-wave lithotripsy of bile duct stones

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Lee, Jong Tae; Kim, Myung Joon; Yoo, Hyung Sik; Suh, Jung Ho; Lee, Moo Sang; Jo, Jang Hwan; Kim, Byung Ro [Yonsei University College of Medicine, Seoul (Korea, Republic of)

1989-12-15

During the past one and half year, we performed ESWL therapy in 13 patients with common bile duct and intrahepatic duct stones, applying Lithostar-R (Siemens co. West Germany) and analyzed their results. In 13 patients, 9 residual common bile duct stones and 7 intrahepatic duct stones were selected postoperatively. The size of stones were ranged from 0.7 cm to 3.5 cm in diameter. 2 stones were multiple and the remained 14 were single in number. The visualization of stones were done with fluoroscopy after the injection of contrast media via cholangiographic T-tube or ERCP. ESWL were applied continuously until stone disintegration was visible, or upto maximum number of 3500 discharge of shock wave. If not disintegrated upto 3500, patients were underwent second or third lithotripsy session with interval of one week. Our results showed that among 9 common bile duct stones, 4 were completely disintegrated and passed out spontaneously, but 3 partially fragmented and removed by the additional procedure. 2 were failed. Among 7 intrahepatic stones, 3 completely and 2 partially were succeeded. One stone partially fragmented were retained without removal and other one were failed. Skin petechia in all patients were revealed on the entry port of shock wave, but no serous complication was not occurred.

Pediatric extracorporeal shock wave lithotripsy: Predicting successful outcomes

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Sean McAdams

2010-01-01

Full Text Available Extracorporeal shock wave lithotripsy (ESWL is currently a first-line procedure of most upper urinary tract stones <2 cm of size because of established success rates, its minimal invasiveness and long-term safety with minimal complications. Given that alternative surgical and endourological options exist for the management of stone disease and that ESWL failure often results in the need for repeat ESWL or secondary procedures, it is highly desirable to identify variables predicting successful outcomes of ESWL in the pediatric population. Despite numerous reports and growing experience, few prospective studies and guidelines for pediatric ESWL have been completed. Variation in the methods by which study parameters are measured and reported can make it difficult to compare individual studies or make definitive recommendations. There is ongoing work and a need for continuing improvement of imaging protocols in children with renal colic, with a current focus on minimizing exposure to ionizing radiation, perhaps utilizing advancements in ultrasound and magnetic resonance imaging. This report provides a review of the current literature evaluating the patient attributes and stone factors that may be predictive of successful ESWL outcomes along with reviewing the role of pre-operative imaging and considerations for patient safety.

The value of antibiotic prophylaxis during extracorporeal shock wave lithotripsy in the prevention of urinary tract infections in patients with urine proven sterile prior to treatment

NARCIS (Netherlands)

Bierkens, A. F.; Hendrikx, A. J.; Ezz el Din, K. E.; de la Rosette, J. J.; Horrevorts, A.; Doesburg, W.; Debruyne, F. M.

1997-01-01

There are controversies in the literature regarding the need for and duration of antibiotic prophylaxis in patients treated with extracorporeal shock wave lithotripsy (ESWL) who have a negative urine culture before treatment. In order to determine the efficacy of antibiotic prophylaxis in ESWL

Does Stepwise Voltage Ramping Protect the Kidney from Injury During Extracorporeal Shockwave Lithotripsy? Results of a Prospective Randomized Trial.

Science.gov (United States)

Skuginna, Veronika; Nguyen, Daniel P; Seiler, Roland; Kiss, Bernhard; Thalmann, George N; Roth, Beat

2016-02-01

Renal damage is more frequent with new-generation lithotripters. However, animal studies suggest that voltage ramping minimizes the risk of complications following extracorporeal shock wave lithotripsy (SWL). In the clinical setting, the optimal voltage strategy remains unclear. To evaluate whether stepwise voltage ramping can protect the kidney from damage during SWL. A total of 418 patients with solitary or multiple unilateral kidney stones were randomized to receive SWL using a Modulith SLX-F2 lithotripter with either stepwise voltage ramping (n=213) or a fixed maximal voltage (n=205). SWL. The primary outcome was sonographic evidence of renal hematomas. Secondary outcomes included levels of urinary markers of renal damage, stone disintegration, stone-free rate, and rates of secondary interventions within 3 mo of SWL. Descriptive statistics were used to compare clinical outcomes between the two groups. A logistic regression model was generated to assess predictors of hematomas. Significantly fewer hematomas occurred in the ramping group(12/213, 5.6%) than in the fixed group (27/205, 13%; p=0.008). There was some evidence that the fixed group had higher urinary β2-microglobulin levels after SWL compared to the ramping group (p=0.06). Urinary microalbumin levels, stone disintegration, stone-free rate, and rates of secondary interventions did not significantly differ between the groups. The logistic regression model showed a significantly higher risk of renal hematomas in older patients (odds ratio [OR] 1.03, 95% confidence interval [CI] 1.00-1.05; p=0.04). Stepwise voltage ramping was associated with a lower risk of hematomas (OR 0.39, 95% CI 0.19-0.80; p=0.01). The study was limited by the use of ultrasound to detect hematomas. In this prospective randomized study, stepwise voltage ramping during SWL was associated with a lower risk of renal damage compared to a fixed maximal voltage without compromising treatment effectiveness. Lithotripsy is a noninvasive

Massive retroperitoneal haemorrhage after extracorporeal shock wave lithotripsy (ESWL).

Science.gov (United States)

Inoue, Hiromasa; Kamphausen, Thomas; Bajanowski, Thomas; Trübner, Kurt

2011-01-01

A 76-year-old male suffering from nephrolithiasis developed a shock syndrome 5 days after extracorporal shock wave lithotripsy (ESWL). CT scan of the abdomen showed massive haemorrhage around the right kidney. Although nephrectomy was performed immediately, the haemorrhage could not be controlled. Numerous units of erythrocytes were transfused, but the patient died. The autopsy revealed massive retroperitoneal haemorrhage around the right kidney. The kidney showed a subcapsular haematoma and a rupture of the capsule. The right renal artery was dissected. The inferior vena cava was lacerated. Accordingly, a hemorrhagic shock as the cause of death was determined, which might mainly have resulted from the laceration of the inferior vena cava due to ESWL. ESWL seems to be a relatively non-invasive modality, but one of its severe complications is perirenal hematoma. The injuries of the blood vessels might have been caused by excessive shock waves. Subsequently, anticoagulation therapy had been resumed 3 days after EWSL, which might have triggered the haemorrhage. Physicians should note that a haemorrhage after an ESWL can occur and they should pay attention to the postoperative management in aged individuals especially when they are under anticoagulation therapy.

Renal morphology and function immediately after extracorporeal shock-wave lithotripsy

Energy Technology Data Exchange (ETDEWEB)

Kaude, J.V.; Williams, C.M.; Millner, M.R.; Scott, K.N.; Finlayson, B.

1985-08-01

The acute effects of extracorporeal shock-wave lithotripsy (ESWL) on morphology and function of the kidney were evaluated by excretory urography, quantitative radionuclide renography (QRR), and magnetic resonance imaging (MRI) in 33 consecutive patients. Excretory urograms demonstrated an enlarged kidney in seven (18%) of 41 treatments and partial or complete obstruction of the ureter by stone fragments after 15 (37%) of 41 treatments. Total effective renal plasma flow (ERPF) was not changed after ESWL, but the percentage ERPF of the treated kidney was decreased by more than 5% in 10 (30%) of 33 cases. QRR images showed partial parenchymal obstruction in 10 (25%) of 41 teated kidneys and total parenchymal obstruction in 9 (22%). MRI disclosed one or more abnormalities in 24 (63%) of 38 treated kidneys. Treated kidneys were normal by all three imaging methods in 26% and abnormal by one or more tests in 74% of cases. The morphologic and functional changes are attributed to renal contusion resulting in edema and extravasation of urine and blood into the interstitial, subcapsular, and perirenal spaces.

US evaluation in extracorporeal shock wave lithotripsy

International Nuclear Information System (INIS)

Baumgartner, B.R.; Steinberg, H.V.; Ambrose, S.S.; Walton, K.N.; Bernardino, M.E.

1986-01-01

Real-time US was performed in 100 consecutive patients the day preceding and/or 24 and 48 hours after extracorporeal shock wave lithotripsy (ESWL) therapy. In the 87 treated kidneys containing three or fewer stones, a total of 111 stones were found; 104 were radiopaque. Pre-ESWL US was not available for six stones. Sixty-eight stones (64.5%) were visualized. Of the 37 stones not seen, 10 (27%) were ≤ 5 mm in diameter, and of the larger stones, 19 (51%) were in the ureter or ureteropelvic junction; only six (16%) were in the calyces, and two (5%) were in the renal pelvis. Comparison of pre-ESWL and post-ESWL in 80 kidneys revealed no change in 37 (46%), more stones or fragments detected in 23 (29%), fewer stones or a change in location of stones in 12 (15%), and decreased size of the original stone in eight (10%). The ability of US to detect renal calculi seems to be related not only to stone size but also to location. Hydronephrosis was detected on pre-ESWL US in 16 kidneys (20%). After ESWL the hydronephrosis did not change in seven, decreased or resolved in eight, and increased in only one. Hydronephrosis was noted to develop after ESWL in 21 (26%) other kidneys. Pre-ESWL and post-ESWL hydronephrosis found on US must be considered in conjunction with the clinical picture and other radiographic studies

Prediction of the energy required for extracorporeal shock wave lithotripsy of certain stones composition using simple radiology and computerized axial tomography.

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Argüelles-Salido, E; Campoy-Martínez, P; Aguilar-García, J; Podio-Lora, V; Medina-López, R

2014-03-01

To demonstrate that urinary lithiasis have a specific susceptibility to fracture through extracorporeal shock wave lithotripsy (ESWL), which is common for all calculi with the same composition and which can be estimated before treatment using CT or plain x-ray. We present an in vitro, prospective, randomized, blind and multi-centre study involving 308 urinary calculi. 193 of these met the inclusion criteria: whole calculi composed purely of calcium oxalate monohydrate (COM), uric acid (UA) or carbonate apatite (CA), or a mix of oxalate (COMix) and of a size greater than 0.5 cm. The samples were broken using lithotripsy until reaching a pre-established level of comminution. The variables employed were energy dose (Edose) per cm(3) of lithiasis and Edose adjusted to lithiasic surface (EdAJ) per cm(3). COM was the hardest, requiring an Edose of 119,624 mJ/cm(3) and an EdAJ of 36,983 mJ/cm(3), followed by COMix (75,501/36,983), CA (22,734/21,186) and UA (22,580/6,837) (P energy in order to be broken by ESWL, which is inherent to all those sharing the same composition, and can be predicted using CT or plain x-ray. Copyright © 2013 AEU. Published by Elsevier Espana. All rights reserved.

Ultrasound shock wave generator with one-bit time reversal in a dispersive medium, application to lithotripsy

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Montaldo, Gabriel; Roux, Philippe; Derode, Arnaud; Negreira, Carlos; Fink, Mathias

2002-02-01

The building of high-power ultrasonic sources from piezoelectric ceramics is limited by the maximum voltage that the ceramics can endure. We have conceived a device that uses a small number of piezoelectric transducers fastened to a cylindrical metallic waveguide. A one-bit time- reversal operation transforms the long-lasting low-level dispersed wave forms into a sharp pulse, thus taking advantage of dispersion to generate high-power ultrasound. The pressure amplitude that is generated at the focus is found to be 15 times greater than that achieved with comparable standard techniques. Applications to lithotripsy are discussed and the destructive efficiency of the system is demonstrated on pieces of chalk.

Evaluating the importance of mean stone density and skin-to-stone distance in predicting successful shock wave lithotripsy of renal and ureteric calculi.

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Wiesenthal, Joshua D; Ghiculete, Daniela; D'A Honey, R John; Pace, Kenneth T

2010-08-01

Shock wave lithotripsy (SWL) is considered the first line treatment for the majority of patients with renal and ureteric calculi, with success rates from contemporary series varying from 60 to 90%. Success is dependent on many patient and stone-related factors. We conducted a retrospective analysis of mean stone CT density (MSD) and skin-to-stone distance (SSD) to determine their influence on the success of SWL of renal and ureteric calculi. Data from all patients treated at the St. Michael's Hospital Lithotripsy Unit from May 2004 to June 2009 were reviewed. Analysis was restricted to those patients with a pre-treatment non-contrast CT scan conducted at our center demonstrating a solitary renal or ureteric calculus 900 HU (OR = 0.49, CI: 0.32-0.75) and SSD >110 mm (OR = 0.49, CI: 0.31-0.78) were both significant predictors of outcome. We have identified in a large series of renal and ureteric calculi that both MSD and SSD can reliably predict SWL outcomes. This data can be used in combination with other patient and stone-related factors to facilitate optimal treatment-based decisions and provide patients with more accurate single-treatment success rates for SWL.

[Extracorporeal shock-wave lithotripsy of gallstones].

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Freund, H R; Lebensart, P D; Muggia-Sullam, M; Durst, A L

1989-08-01

We performed 16 extracorporeal shock-wave lithotripsies (ESWL) to fragment gallstones in 11 women and 2 men, aged 19 to 57 (mean 41 +/- 10) years, during the past 10 months. Criteria for selection included a history of biliary colic, not more than 3 stones with a total diameter of not more than 30 mm, and a functioning gallbladder. 210 patients were examined, of whom 98 were referred for additional screening by combined ultrasonography and oral cholecystography. This resulted in rejection of another 71 patients due to multiple stones (38%), nonfunctioning gallbladder (22%), calcified stones (12%), stones not visualized in the prone position (9%), excessively large stones (3%) and other reasons (16%). Only 27 patients fulfilled all the criteria. Under epidural or general anesthesia (11 and 2 patients, respectively), we administered 1200-3500 (mean 2250 +/- 750) shock waves at 20-24 KV with the Tripter X1 (Direx, Israel-USA). This is an ultrasound-guided, modular portable, shock-wave generator utilizing underwater high energy spark discharge. Chenodeoxycholic or ursodeoxycholic acid, 10 mg/kg/day, was started 1 week prior to ESWL and continued for 3 months after disappearance of fragments and debris. We encountered skin petechiae in all patients, transient hematuria in 8, mild biliary colic in 1 and a small liver hematoma in 1. To date, 3 patients are free of stones, while in 7 only sludge and tiny fragments are present which we expect to disappear as a result of the litholytic therapy. 3 patients had fragments larger than 5 mm and required a second ESWL. Thus ESWL, which was indicated in only 13% of screened patients, proved to be safe and can be expected to be successful in 75% of selected candidates.

Transurethral lithotripsy with holmium-YAG laser of a large exogenous prostatic calculus.

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Hasegawa, Masanori; Ohara, Rei; Kanao, Kent; Nakajima, Yosuke

2011-04-01

Prostatic calculi are classified into two types, endogenous and exogenous calculi, based on their origin. Endogenous calculi are commonly observed in elderly men; however, exogenous prostatic calculi are extremely rare. We report here the case of a 51-year-old man who suffered incontinence and pollakiuria with a giant exogenous prostatic calculus almost completely replacing the prostatic tissue. X-rays and computed tomography demonstrated a large calculus of 65 × 58 mm in the small pelvic cavity. The patient underwent a transurethral lithotripsy with a holmium-YAG laser and a total of 85 g of disintegrated stones was retrieved and chemical stone analysis revealed the presence of magnesium ammonium phosphate. The incontinence improved and the voiding volume increased dramatically, and no stone recurrence in the prostatic fossa occurred at the 2 years follow-up. The etiology of this stone formation seemed to be based on some exogenous pathways combined with urinary stasis and chronic urinary infection due to compression fracture of the lumbar vertebra.

Renal damage after extracorporeal shock-wave lithotripsy detected by magnetic resonance imaging

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Torii, Shinichiro; Machida, Toyohei; Ooishi, Yukihiko; Tashiro, Kazuya; Mochizuki, Atsushi; Yoshigoe, Fukuo

1988-08-01

The acute effects of extracorporeal Shock-wave lithotripsy (ESWL) on morphology of the renal parenchyma were evaluated by Magnetic Resonance Imaging (MRI) in 15 kidneys, before and immediately after (within 24 hours) ESWL in 11 cases. The renal parenchymal damages were observed by MRI as the changes of signal itensity of renal cortex and medulla, perirenal fluid, loss of corticomedullar differentiation, and other renal traumas. Loss of corticomedullar differentiation was seen in 9/11 cases and peripheral fluid of the kidney was seen in 4/11 cases. Irregular and edematous changes of renal capsula were seen in 5/11 cases. Obvious abnormal findings indicated renal trauma were not observed in this study. Several MRI findings may transient and reversible changes and the morpholigic changes detected by MRI may attributed to renal parenchymal obstruction and edema and decreasing of renal capillary flow, such as in renal contusion. It is concluded that MRI is very sensitive and the best technique to detect the effects and clinical trouble of ESWL.

Serious clopidogrel associated renal hematoma in a type 2 diabetic patient with primary hyperparathyroidism after extracorporeal shock wave lithotripsy

International Nuclear Information System (INIS)

Bahceci, Mithat; Tuzcu, Alpaslan; Agil, Cuneyt; Akay, Ferruh; Akay, Hatice

2005-01-01

Renal hematoma after extracorporeal shock wave lithotripsy SWL is a rare complication. We report a case of a large renal hematoma following SWL that resulted in nephrectomy in a type 2 diabetic patient with primary hyperparathyroidism using clopidogrel due to coronary heart disease CHD. Although it was claimed that preoperative use of clopidogrel was not associated with increased bleeding, all patients who are scheduled for SWL should be interrogated in terms of using of platelet aggregation inhibitors such as clopidogrel, and these drugs should be interrupted appropriately before undergoing SWL. (author)

Variables influencing radiation exposure during extracorporeal shock wave lithotripsy. Review of 298 treatments

International Nuclear Information System (INIS)

Carter, H.B.; Naeslund, E.B.R.; Riehle, R.A. Jr.

1987-01-01

Retrospective review of 298 extracorporeal shock wave lithotripsy (ESWL) treatments was undertaken to determine the factors which influence radiation exposure during ESWL. Fluoroscopy time averaged 160 seconds (3-509), and the average number of spot films taken per patient was 26 (5-68). The average stone burden was 19.3 mm (3-64). Average calculated skin surface radiation exposure was 17.8 R per treatment. Radiation exposure increased with increasing stone burden and patient weight. Stones treated in the ureter resulted in a higher average patient radiation exposure than for renal stones (19 R vs 16 R), even though the average size of these ureteral stones (11.3 mm) was significantly less than the mean. However, type of anesthetic (general or regional) used was not a significant factor. Operator training, experience, and familiarity with radiation physics should significantly decrease the amount of imaging time and consequent patient radiation exposure during ESWL

Variables influencing radiation exposure during extracorporeal shock wave lithotripsy. Review of 298 treatments

Energy Technology Data Exchange (ETDEWEB)

Carter, H.B.; Naeslund, E.B.R.; Riehle, R.A. Jr.

1987-12-01

Retrospective review of 298 extracorporeal shock wave lithotripsy (ESWL) treatments was undertaken to determine the factors which influence radiation exposure during ESWL. Fluoroscopy time averaged 160 seconds (3-509), and the average number of spot films taken per patient was 26 (5-68). The average stone burden was 19.3 mm (3-64). Average calculated skin surface radiation exposure was 17.8 R per treatment. Radiation exposure increased with increasing stone burden and patient weight. Stones treated in the ureter resulted in a higher average patient radiation exposure than for renal stones (19 R vs 16 R), even though the average size of these ureteral stones (11.3 mm) was significantly less than the mean. However, type of anesthetic (general or regional) used was not a significant factor. Operator training, experience, and familiarity with radiation physics should significantly decrease the amount of imaging time and consequent patient radiation exposure during ESWL.

Intraluminal bubble dynamics induced by lithotripsy shock wave

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Song, Jie; Bai, Jiaming; Zhou, Yufeng

2016-12-01

Extracorporeal shock wave lithotripsy (ESWL) has been the first option in the treatment of calculi in the upper urinary tract since its introduction. ESWL-induced renal injury is also found after treatment and is assumed to associate with intraluminal bubble dynamics. To further understand the interaction of bubble expansion and collapse with the vessel wall, the finite element method (FEM) was used to simulate intraluminal bubble dynamics and calculate the distribution of stress in the vessel wall and surrounding soft tissue during cavitation. The effects of peak pressure, vessel size, and stiffness of soft tissue were investigated. Significant dilation on the vessel wall occurs after contacting with rapid and large bubble expansion, and then vessel deformation propagates in the axial direction. During bubble collapse, large shear stress is found to be applied to the vessel wall at a clinical lithotripter setting (i.e. 40 MPa peak pressure), which may be the mechanism of ESWL-induced vessel rupture. The decrease of vessel size and viscosity of soft tissue would enhance vessel deformation and, consequently, increase the generated shear stress and normal stresses. Meanwhile, a significantly asymmetric bubble boundary is also found due to faster axial bubble expansion and shrinkage than in radial direction, and deformation of the vessel wall may result in the formation of microjets in the axial direction. Therefore, this numerical work would illustrate the mechanism of ESWL-induced tissue injury in order to develop appropriate counteractive strategies for reduced adverse effects.

Application of Underwater Shock Wave Focusing to the Development of Extracorporeal Shock Wave Lithotripsy

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Takayama, Kazuyoshi

1993-05-01

This paper describes a summary of a research project for the development of extracorporeal shock wave lithotripsy (ESWL), which has been carried out, under close collaboration between the Shock Wave Research Center of Tohoku University and the School of Medicine, Tohoku University. The ESWL is a noninvasive clinical treatment of disintegrating human calculi and one of the most peaceful applications of shock waves. Underwater spherical shock waves were generated by explosion of microexplosives. Characteristics of the underwater shock waves and of ultrasound focusing were studied by means of holographic interferometric flow visualization and polyvinyliden-difluoride (PVDF) pressure transducers. These focused pressures, when applied to clinical treatments, could effectively and noninvasively disintegrate urinary tract stones or gallbladder stones. However, despite clincal success, tissue damage occurs during ESWL treatments, and the possible mechanism of tissue damage is briefly described.

Trends in urological stone disease.

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Turney, Benjamin W; Reynard, John M; Noble, Jeremy G; Keoghane, Stephen R

2012-04-01

To summarize the changes in prevalence and treatment of upper urinary tract stone disease in the UK over the last 10 years. Data from the Hospital Episode Statistics (HES) website (http://www.hesonline.nhs.uk) were extracted, summarized and presented. The number of upper urinary tract stone hospital episodes increased by 63% to 83,050 in the 10-year period. The use of shock wave lithotripsy (SWL) for treating all upper tract stones increased from 14,491 cases in 2000-2001 to 22,402 cases in 2010 (a 55% increase) with a 69% increase in lithotripsy for renal stones. There was a 127% increase in the number of ureteroscopic stone treatments from 6,283 to 14,242 cases over the 10-year period with a 49% increase from 2007/2008 to 2009/2010. There was a decline in open surgery for upper tract stones from 278 cases in 2000/2001 to 47 cases in 2009/2010 (an 83% reduction). Treatment for stone disease has increased substantially in comparison with other urological activity. In 2009/2010, SWL was performed almost as frequently as transurethral resection of the prostate or transurethral resection of bladder tumour, ureteroscopy for stones was performed more frequently than nephrectomy, radical prostatectomy and cystectomy combined, and percutaneous nephrolithotomy was performed more frequently than cystectomy. The present study highlights the increase in prevalence and treatment of stone disease in the UK over the last 10 years. If this trend continues it has important implications for workforce planning, training, service delivery and research in the field of urolithiasis. © 2011 THE AUTHORS. BJU INTERNATIONAL © 2011 BJU INTERNATIONAL.

Usefulness of Early Extracorporeal Shock Wave Lithotripsy in Colic Patients with Ureteral Stones

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Choi, Hyeung Joon; Jung, Jin-Hee; Bae, Jungbum; Cho, Min Chul; Lee, Hae Won

2012-01-01

Purpose To compare efficacy and safety between early extracorporeal shock wave lithotripsy (eESWL) and deferred ESWL (dESWL) in colic patients with ureteral stones and to investigate whether eESWL can play a critical role in improving treatment outcomes. Materials and Methods A total of 279 patients who underwent ESWL for single radio-opaque ureteral stones of 5 to 20 mm in size were included in this retrospective study. The patients were categorized into two groups according to the time between the onset of colic and ESWL: eESWL (ESWL sessions and less time to achieve stone-free status than did the dESWL group. For 241 patients with stones ESWL complication rates were comparable between the two groups. In the multivariate analysis, smaller stone size and a time to ESWL of <48 hours were independent predictors of success. Conclusions Our data suggest that eESWL in colic patients with ureteral stones is an effective and safe treatment with accelerated stone clearance. PMID:23301130

PROSPECTIVE STUDY TO COMPARE THE EFFICACY OF ANALGESIC AGENTS USED FOR THE PAIN MANAGEMENT DURING EXTRACORPOREAL SHOCK WAVE LITHOTRIPSY

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Abhirudra

2016-05-01

Full Text Available BACKGROUND Extracorporeal shock wave lithotripsy (ESWL is well known for its non-invasiveness, effectiveness and minimal morbidity for the management of renal stones. Some generation of lithotripters were associated with significant pain, needing anaesthesia. In modern lithotripters, pain is insignificant making lithotripsy an outpatient procedure (day care. AIMS The present study is aimed to compare the clinical efficacy between four drugs. METHODS AND MATERIALS This was a prospective study of 1000 patients with normal BMI (25-30 who underwent ESWL in the Year 2012-15 at our institute. All the patients with renal stones were randomly divided into 4 groups. Dornier Compact Sigma lithotripsy machine was used in all the patients. Group A was given IM diclofenac sodium (1 mg/kg, 60 minutes before the procedure. In group B, 10 g of EMLA cream; and in group C, 15 g of diclofenac diethylamine gel; in group D placebo (electrode gel was applied locally. STATISTICAL ANALYSIS Visual analogue scale (VAS was used to assess the severity of pain for initial 5-10 minutes and after the procedure. A P value of less than 0.05 was considered to be statistically significant. Statistical analysis was done using one way ANOVA and results were compared between four groups. RESULTS All four groups were having comparable age, weight, stone size, number of shock waves delivered and maximum voltage used. In group A total 250 patients (M/F: 177/73, group B 250 patients (M/F: 129/121, group C 250 patients (M/F: 158/92, group D 250 patients (M/F: 162/88. With regard to pain scores, the responses were better in group B. According to location of the stones, majority of the stones were located in pelvis (41.5%, followed by upper (30.5% and middle calyx (16.8% and least in the lower calyx (11.2%. Overall stone free rate in our study was 75.5%, with least clearance in lower calyceal stones. 112 patients were stented prior to the procedure. Ureteroscopy and RIRS (Retrograde

Extracorporeal shock wave lithotripsy for pancreatic and large common bile duct stones

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Tandan, Manu; Reddy, D Nageshwar

2011-01-01

Extraction of large pancreatic and common bile duct (CBD) calculi has always challenged the therapeutic endoscopist. Extracorporeal shockwave lithotripsy (ESWL) is an excellent tool for patients with large pancreatic and CBD calculi that are not amenable to routine endotherapy. Pancreatic calculi in the head and body are targeted by ESWL, with an aim to fragment them to ESWL with 5000 shocks being delivered at each session. The use of epidural anesthesia helped in reducing patient movement. This, together with the better focus achieved with newer third-generation lithotripters, prevents collateral tissue damage and minimizes the complications. Complications in our experience with nearly 1300 patients were minimal, and no extension of hospital stay was required. Similar rates of clearance of pancreatic and biliary calculi with minimal adverse effects have been reported from the centers where ESWL is performed regularly. In view of its high efficiency, non-invasive nature and low complication rates, ESWL can be offered as the first-line therapy for selected patients with large pancreatic and CBD calculi. PMID:22110261

Sound field prediction of ultrasonic lithotripsy in water with spheroidal beam equations

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Zhang, Lue; Wang, Xiang-Da; Liu, Xiao-Zhou; Gong, Xiu-Fen

2015-01-01

With converged shock wave, extracorporeal shock wave lithotripsy (ESWL) has become a preferable way to crush human calculi because of its advantages of efficiency and non-intrusion. Nonlinear spheroidal beam equations (SBE) are employed to illustrate the acoustic wave propagation for transducers with a wide aperture angle. To predict the acoustic field distribution precisely, boundary conditions are obtained for the SBE model of the monochromatic wave when the source is located on the focus of an ESWL transducer. Numerical results of the monochromatic wave propagation in water are analyzed and the influences of half-angle, fundamental frequency, and initial pressure are investigated. According to our results, with optimization of these factors, the pressure focal gain of ESWL can be enhanced and the effectiveness of treatment can be improved. Project supported by the National Basic Research Program of China (Grant Nos. 2012CB921504 and 2011CB707902), the National Natural Science Foundation of China (Grant No. 11274166), the State Key Laboratory of Acoustics, Chinese Academy of Sciences (Grant No. SKLA201401), and the China Postdoctoral Science Foundation (Grant No. 2013M531313).

Renal damage after extracorporeal shock-wave lithotripsy detected by magnetic resonance imaging

International Nuclear Information System (INIS)

Torii, Shinichiro; Machida, Toyohei; Ooishi, Yukihiko; Tashiro, Kazuya; Mochizuki, Atsushi; Yoshigoe, Fukuo

1988-01-01

The acute effects of extracorporeal Shock-wave lithotripsy (ESWL) on morphology of the renal parenchyma were evaluated by Magnetic Resonance Imaging (MRI) in 15 kidneys, before and immediately after (within 24 hours) ESWL in 11 cases. The renal parenchymal damages were observed by MRI as the changes of signal itensity of renal cortex and medulla, perirenal fluid, loss of corticomedullar differentiation, and other renal traumas. Loss of corticomedullar differentiation was seen in 9/11 cases and peripheral fluid of the kidney was seen in 4/11 cases. Irregular and edematous changes of renal capsula were seen in 5/11 cases. Obvious abnormal findings indicated renal trauma were not observed in this study. Several MRI findings may transient and reversible changes and the morpholigic changes detected by MRI may attributed to renal parenchymal obstruction and edema and decreasing of renal capillary flow, such as in renal contusion. It is concluded that MRI is very sensitive and the best technique to detect the effects and clinical trouble of ESWL. (author)

Does extracorporeal shock wave lithotripsy cause hearing impairment?

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Tuncer, Murat; Erdogan, Banu A; Yazici, Ozgur; Sahin, Cahit; Altin, Gokhan; Faydaci, Gokhan; Eryildirim, Bilal; Sarica, Kemal

2014-07-01

To evaluate the possible effects of extracorporeal shock wave lithotripsy (ESWL) on the hearing status of the patients in this prospective controlled study. A total of 40 patients with normal hearing function were included to the study. We had 20 patients each in the study group and control group. The treatment parameters were standardized in all 3 sessions in which a total of 3000 shock waves with a rate of 90/min along with a total energy value of 126 J at the fourth energy level have been applied (Dornier Compact Sigma, Medtech, Germany). In addition to the testing of hearing functions and possible cochlear impairment by Transient Evoked Otoacoustic Emissions test at 1.0, 1.4, 2.0, 2.8, and 4.0 kHz frequencies, complications such as ear pain, tinnitus, and hearing loss have been well evaluated in each patient before the procedure and 2 hours and 1 month after the completion of the third session of ESWL in the study group. The same evaluation procedures were performed before the study and after 7-weeks in the control group. Regarding Transient Evoked Otoacoustic Emissions data obtained in study group and control group patients, there was no significant alteration in values obtained after ESWL when compared with the values before the procedure. A well-planned ESWL procedure is a safe and effective treatment in urinary stones and causes no detectable harmful effect on the hearing function of treated patients. Copyright © 2014 Elsevier Inc. All rights reserved.

Extracorporeal shock wave lithotripsy: Involvement and impact on radiology at a kidney stone center

International Nuclear Information System (INIS)

Cochran, S.T.; Barbaric, Z.L.; Mindell, H.; Chaussy, C.D.; Fuchs, G.J.

1986-01-01

Of 1,222 extracorporeal shock wave lithotripsy (ECSW) procedures performed on 925 patients (600 males, 325 females), 85% were unilateral and 35% were bilateral treatments. Treated were 446 calyceal, 345 pelvic, 172 uretral, and 108 staghorn calculi. The impact of this new technology to the radiology department was studied. An average of 6.3 KUB studies and 1.2 renal US studies were performed per treatment session. Six percent of patients required post-ESWL excretory urography of CT; 10% required percutaneous nephrostomy. Patients with treated staghorn calculi required the most radiologic procedures (34% performed for partial staghorn calculi, 56% for complete staghorn calculi). By comparison, 3%, 8%, and 11% of radiologic procedures were performed for calyceal, pelvic, and ureteral stones, respectively. The impact of ESWL on the radiology department can be substantial. When staghorn calculi are treated by ESWL, a radiologist skilled in interventional techniques is essential

Can a dual-energy computed tomography predict unsuitable stone components for extracorporeal shock wave lithotripsy?

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Ahn, Sung Hoon; Oh, Tae Hoon; Seo, Ill Young

2015-09-01

To assess the potential of dual-energy computed tomography (DECT) to identify urinary stone components, particularly uric acid and calcium oxalate monohydrate, which are unsuitable for extracorporeal shock wave lithotripsy (ESWL). This clinical study included 246 patients who underwent removal of urinary stones and an analysis of stone components between November 2009 and August 2013. All patients received preoperative DECT using two energy values (80 kVp and 140 kVp). Hounsfield units (HU) were measured and matched to the stone component. Significant differences in HU values were observed between uric acid and nonuric acid stones at the 80 and 140 kVp energy values (penergy values (p<0.001). DECT improved the characterization of urinary stone components and was a useful method for identifying uric acid and calcium oxalate monohydrate stones, which are unsuitable for ESWL.

99mTc-DTPA renography before and after extracorporeal shock wave lithotripsy for renal calculi

International Nuclear Information System (INIS)

Ohtake, Eiji; Murata, Hajime; Kanemura, Mikio; Yokoyama, Masao

1988-01-01

This study was undertaken to evaluate 99m Tc-DTPA renography before and after extracorporeal shock wave lithotripsy (ESWL). Twelve patients with renal calculi were examined in this study. In three patients, bilateral kidneys were treated with ESWL. Sequential renal images of the vascular phase, and the functional and excretory phases were taken using a gamma camera (ZLC 7500, Siemens), after intravenous injection of 555 MBq of 99m Tc-DTPA. Renograms were generated using data stored every 10 seconds for a period of 30 minutes by computer (Scintipac-2400, Shimadzu). Some treated kidneys were enlarged and/or showed uniform retention of radioactivity on sequential images, within a week after ESWL. Renogram patterns after ESWL were varied in each patient. The renogram findings after ESWL seemed to be affected by the presence or absence of stone fragments in the urinary tract. (author)

Effects and outcome of Tamsulosin more than just stone clearance after extracorporeal shock wave lithotripsy for renal calculi

International Nuclear Information System (INIS)

Qadri, S. S. U.; Khalid, S. E.; Mahmud, S. M.

2014-01-01

Objective: To determine the effect of Tamsulosin, as adjunctive medical therapy after Extracorporeal Shock Wave Lithotripsy for renal stones on rate of stone clearance, clearance time, pain intensity during stone clearance, steinstrasse formation and auxiliary surgical intervention required. Method: A prospective randomized controlled study was carried out in 120 patients who underwent ESWL for renal stones of 0.5-2.0 cm. They were randomized into study and control group in which Tamsulosin 0.4mg/day was given in former as an adjunctive medical therapy. All patients underwent ESWL every 2 weeks until complete stone clearance for 8 weeks. The parameters assessed were stone clearance, clearance time, pain intensity and effect on steinstrasse. Results: Of the 120 patients 60 were in each group. The stone clearance rate was greater in study than in control group, 58(96.7%) vs. 48(80%) respectively, (p<0.004). The mean stone clearance time was observed earlier in study group as compared to control group with significant statistical difference in stone size between 0.6-1.5 cm. The mean intensity of pain patients experienced according to Visual analogue scale (VAS) was significantly less in study group (p<0.002). The rate of steinstrasse formation was observed to be higher in control than in study group 15(25%) vs 6(10%) respectively(p<0.003), while its spontaneous clearance was higher in study group than in control group 83.3% vs 33.3% (p<0.03). Conclusion: Tamsulosin significantly increases stone clearance after shock wave lithotripsy for renal stones. It also appeared to facilitate earlier stone clearance, reduces severity of pain, reduces the incidence of steinstrasse formation and tends to facilitate its spontaneous clearance. (author)

Effects of flexible ureteroscopy on renal blood flow: a prospective evaluation.

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Sener, Tarik Emre; Tanidir, Yiloren; Bin Hamri, Saeed; Sever, Ibrahim Halil; Ozdemir, Burcu; Al-Humam, Abdulla; Traxer, Olivier

2018-02-20

This study aimed to investigate the effects of flexible ureteroscopy (F-URS) on renal blood flow using renal Doppler ultrasound (US). Patients undergoing F-URS were scheduled for Doppler US preoperatively and postoperatively. Peak systolic velocity (PSV), end-diastolic velocity (EDV), resistive index (RI) and pulsatility index (PI) were reported. Technical details, operation time, stone characteristics and complications were recorded. Patients were grouped as 9.5/11.5-Flex-X2, 10/12-Flex-X2, 10/12-Flex-XC, 12/14-Flex-X2 and 12/14-Flex-XC, with 28, six, three, seven and two patients in each group, respectively. Forty-six patients with a mean age of 41.24 years and stone volume of 1685 mm³ were enrolled. The PSV, EDV, PI and RI of renal arteries in all groups in preoperative and postoperative periods were similar. Arcuate artery measurements in all groups were also similar in preoperative and postoperative periods, without any significant difference except in two parameters: RI in the 9.5/11.5-Flex-X2 group and PSV in the 12/14-Flex-X2 group. The resistive index in the arcuate artery of the 9.5/11.5-Flex-X2 group was increased from 0.59 to 0.62 cm/sec postoperatively. The PSV in the arcuate artery of the 12/14-Flex-X2 group was decreased from 30.9 to 27.2 cm/sec. Three patients had urinary tract infections postoperatively and two had sepsis. This study suggests that compatible ureteroscope-ureteral access sheath combinations with a lumen difference of more than 1.5 Fr can provide safe outcomes in terms of renal blood flow. F-URS can safely be performed in terms of renal perfusion and complication rates with appropriate equipment and instruments.

An exceedingly rare cause of secondary hypertension: bilateral renal artery dissection possibly secondary to extracorporeal shock-wave lithotripsy (ESWL).

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Orhan, Ozbek; Kultigin, Turkmen; Osman, Koc; Yalcin, Solak; Melih, Anil; Niyazi, Gormus

2011-01-01

Extracorporeal shock-wave lithotripsy (ESWL) is an effective and relatively non-invasive treatment modality for ureteral or renal calculi. Although it has been accepted as a safe procedure, minor and major complications have been reported after ESWL. Spontaneous renal artery dissection (SRAD) is a rare and usually misdiagnosed condition because of non-specific presentation of the patients. Depending on the severity of the extent of the dissection non-operative or surgical treatment modalities could be performed. We represent a patient with complaints of bilateral flank pain, hematuria and hypertensive urgency who was diagnosed as having bilateral SRAD possibly secondary to ESWL and chronic hypertension.

Anti-miss-shot control device for selective stone disintegration in extracorporeal shock wave lithotripsy

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Kuwahara, M.; Ioritani, N.; Kambe, K.; Orikasa, S.; Takayama, K.

1991-06-01

A new device to prevent erroneously focused shock waves to the renal parenchyma during extracorporeal shock wave lithotripsy (ESWL) has been developed; an anti-miss-shot control device (AMCD) and experiments have been conducted to evaluate its effectiveness. For shock wave generation and stone localization, piezoceramic elements (PSE) and ultrasound localization, respectively were used. After stone localization, probing ultrasounds (PU) were emmitted from the PSE towards the focal region and the reflected sound levels (RSL) were monitored by the PSE which also functioned as a microphone. A direct hit by the PU to the stone or a miss was judged from the RSL, i.e. a high RSL indicates a direct hit and a low RSL indicates a miss. Shock waves were generated only when the RSL exceeded the level which indicated a direct hit. The experimental results showed that the injury to the renal parenchyma was decreased by using the AMCD. Clinical application of the AMCD is expected to increase the safety of ESWL.

A novel stone retrieval basket for more efficient lithotripsy procedures.

Science.gov (United States)

Salimi, N; Mahajan, A; Don, J; Schwartz, B

2009-01-01

This paper presents the development of an improved stone retrieval device that uses a newly designed cage of Nitinol wires encompassing a mesh basket made of a material that is laser resistant. Current methods to extract large stones involve imaging, using a laser to fragment the stones and then using existing cage-like baskets to trap the fragments individually and extracting them one at a time. These procedures are tedious, and may result in leaving some fragments behind that can reform causing the need for another procedure. The device presented in this paper will have a mesh-like sack which will consist of a laser resistant material of polytetrafluoroethylene (PTFE) enclosed within a newly designed Nitinol cage. Two alternate designs are provided for the cage in this paper. The handle of the device is revised to allow for a 3 Fr (1 mm) opening such that a laser's fiber optic cable can enter the device. Using this device a laser can be used to fragment the stone, and all the fragments are retained in the basket in both the design options. The basket can then be retracted allowing for the retrieval of all the fragments in one shot. The stone retrieval basket presented in this paper will significantly improve the efficiency and effectiveness of lithotripsy procedures for removal of large kidney and biliary tract stones.

Efficacy of second generation lithotriptors: a multicenter comparative study of 2,206 extracorporeal shock wave lithotripsy treatments with the Siemens Lithostar, Dornier HM4, Wolf Piezolith 2300, Direx Tripter X-1 and Breakstone lithotriptors

NARCIS (Netherlands)

Bierkens, A. F.; Hendrikx, A. J.; de Kort, V. J.; de Reyke, T.; Bruynen, C. A.; Bouve, E. R.; Beek, T. V.; Vos, P.; Berkel, H. V.

1992-01-01

Extracorporeal shock wave lithotripsy (ESWL) has become the treatment of choice for urinary calculi. The good results of the first generation Dornier HM3 lithotriptor stimulated the development of second generation machines. A multicenter trial is presented involving the Siemens Lithostar, Dornier

Comparison of High, Intermediate, and Low Frequency Shock Wave Lithotripsy for Urinary Tract Stone Disease: Systematic Review and Network Meta-Analysis.

Science.gov (United States)

Kang, Dong Hyuk; Cho, Kang Su; Ham, Won Sik; Lee, Hyungmin; Kwon, Jong Kyou; Choi, Young Deuk; Lee, Joo Yong

2016-01-01

To perform a systematic review and network meta-analysis of randomized controlled trials (RCTs) to determine the optimal shock wave lithotripsy (SWL) frequency range for treating urinary stones, i.e., high-frequency (100-120 waves/minute), intermediate-frequency (80-90 waves/minute), and low-frequency (60-70 waves/minute) lithotripsy. Relevant RCTs were identified from electronic databases for meta-analysis of SWL success and complication rates. Using pairwise and network meta-analyses, comparisons were made by qualitative and quantitative syntheses. Outcome variables are provided as odds ratios (ORs) with 95% confidence intervals (CIs). Thirteen articles were included in the qualitative and quantitative synthesis using pairwise and network meta-analyses. On pairwise meta-analyses, comparable inter-study heterogeneity was observed for the success rate. On network meta-analyses, the success rates of low- (OR 2.2; 95% CI 1.5-2.6) and intermediate-frequency SWL (OR 2.5; 95% CI 1.3-4.6) were higher than high-frequency SWL. Forest plots from the network meta-analysis showed no significant differences in the success rate between low-frequency SWL versus intermediate-frequency SWL (OR 0.87; 95% CI 0.51-1.7). There were no differences in complication rate across different SWL frequency ranges. By rank-probability testing, intermediate-frequency SWL was ranked highest for success rate, followed by low-frequency and high-frequency SWL. Low-frequency SWL was also ranked highest for low complication rate, with high- and intermediate-frequency SWL ranked lower. Intermediate- and low-frequency SWL have better treatment outcomes than high-frequency SWL when considering both efficacy and complication.

Flexibility.

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Humphrey, L. Dennis

1981-01-01

Flexibility is an important aspect of all sports and recreational activities. Flexibility can be developed and maintained by stretching exercises. Exercises designed to develop flexibility in ankle joints, knees, hips, and the lower back are presented. (JN)

[Non-biological 3D printed simulator for training in percutaneous nephro- lithotripsy].

Science.gov (United States)

Alyaev, Yu G; Sirota, E S; Bezrukov, E A; Ali, S Kh; Bukatov, M D; Letunovskiy, A V; Byadretdinov, I Sh

2018-03-01

To develop a non-biological 3D printed simulator for training and preoperative planning in percutaneous nephrolithotripsy (PCNL), which allows doctors to master and perform all stages of the operation under ultrasound and fluoroscopy guidance. The 3D model was constructed using multislice spiral computed tomography (MSCT) images of a patient with staghorn urolithiasis. The MSCT data were processed and used to print the model. The simulator consisted of two parts: a non-biological 3D printed soft model of a kidney with reproduced intra-renal vascular and collecting systems and a printed 3D model of a human body. Using this 3D printed simulator, PCNL was performed in the interventional radiology operating room under ultrasound and fluoroscopy guidance. The designed 3D printed model of the kidney completely reproduces the individual features of the intra-renal structures of the particular patient. During the training, all the main stages of PCNL were performed successfully: the puncture, dilation of the nephrostomy tract, endoscopic examination, intra-renal lithotripsy. Our proprietary 3D-printed simulator is a promising development in the field of endourologic training and preoperative planning in the treatment of complicated forms of urolithiasis.

/sup 99m/Tc-DTPA renography before and after extracorporeal shock wave lithotripsy for renal calculi

Energy Technology Data Exchange (ETDEWEB)

Ohtake, Eiji; Murata, Hajime; Kanemura, Mikio; Yokoyama, Masao

1988-09-01

This study was undertaken to evaluate /sup 99m/Tc-DTPA renography before and after extracorporeal shock wave lithotripsy (ESWL). Twelve patients with renal calculi were examined in this study. In three patients, bilateral kidneys were treated with ESWL. Sequential renal images of the vascular phase, and the functional and excretory phases were taken using a gamma camera (ZLC 7500, Siemens), after intravenous injection of 555 MBq of /sup 99m/Tc-DTPA. Renograms were generated using data stored every 10 seconds for a period of 30 minutes by computer (Scintipac-2400, Shimadzu). Some treated kidneys were enlarged and/or showed uniform retention of radioactivity on sequential images, within a week after ESWL. Renogram patterns after ESWL were varied in each patient. The renogram findings after ESWL seemed to be affected by the presence or absence of stone fragments in the urinary tract.

The Cost-Effectiveness of Treatment Modalities for Ureteral Stones

Directory of Open Access Journals (Sweden)

Justin Ji-Yuen Siu MD

2016-10-01

Full Text Available Additional intervention and medical treatment of complications may follow the primary treatment of a ureteral stone. We investigated the cost of the treatment of ureteral stone(s within 45 days after initial intervention by means of retrospective analysis of the National Health Insurance Research Database of Taiwan. All patients of ages ≥20 years diagnosed with ureteral stone(s( International Classification of Diseases, Ninth Revision, Clinical Modification/ICD-9-CM: 592.1 from January 2001 to December 2011 were enrolled. We included a comorbidity code only if the diagnosis appeared in at least 2 separate claims in a patient’s record. Treatment modalities (code included extracorporeal shock-wave lithotripsy (SWL; 98.51, ureteroscopic lithotripsy (URSL; 56.31, percutaneous nephrolithotripsy (PNL; 55.04, (open ureterolithotomy (56.20, and laparoscopy (ie, laparoscopic ureterolithotomy; 54.21. There were 28 513 patients with ureteral stones (13 848 men and 14 665 women in the randomized sample of 1 million patients. The mean cost was 526.4 ± 724.1 United States Dollar (USD. The costs of treatment were significantly increased in patients with comorbidities. The costs of treatment among each primary treatment modalities were 1212.2 ± 627.3, 1146.7 ± 816.8, 2507.4 ± 1333.5, 1533.3 ± 1137.1, 2566.4 ± 2594.3, and 209.8 ± 473.2 USD in the SWL, URSL, PNL, (open ureterolithotomy, laparoscopy (laparoscopic ureterolithotomy, and conservative treatment group, respectively. In conclusion, URSL was more cost-effective than SWL and PNL as a primary treatment modality for ureteral stone(s when the possible additional costs within 45 days after the initial operation were included in the calculation.

Addition of Sodium Bicarbonate to Irrigation Solution May Assist in Dissolution of Uric Acid Fragments During Ureteroscopy.

Science.gov (United States)

Paonessa, Jessica E; Williams, James C; Lingeman, James E

2018-04-01

We hypothesized that adding sodium bicarbonate (bicarb) to normal saline (NS) irrigation during ureteroscopy in patients with uric acid (UA) nephrolithiasis may assist in dissolving small stone fragments produced during laser lithotripsy. In vitro testing was performed to determine whether dissolution of UA fragments could be accomplished within 1 hour. In total 100% UA renal calculi were fragmented, filtered, and separated by size. Fragment sizes were <0.5 mm and 0.5 to 1 mm. Similar amounts of stone material were agitated in solution at room temperature. Four solutions were tested (NS, NS +1 ampule bicarb/L, NS +2, NS +3). Both groups were filtered to remove solutions after fixed periods. Filtered specimens were dried and weighed. Fragment dissolution rates were calculated as percent removed per hour. Additional testing was performed to determine whether increasing the temperature of solution affected dissolution rates. For fragments <0.5 mm, adding 2 or 3 bicarb ampules/L NS produced a dissolution rate averaging 91% ± 29% per hour. This rate averaged 226% faster than NS alone. With fragments 0.5 to 1 mm, addition of 2 or 3 bicarb ampules/L NS yielded a dissolution rate averaging 22% ± 7% per hour, which was nearly five times higher than NS alone. There was a trend for an increase in mean dissolution rate with higher temperature but this increase was not significant (p = 0.30). The addition of bicarbonate to NS more than doubles the dissolution rate of UA stone fragments and fragments less than 0.5 mm can be completely dissolved within 1 hour. Addition of bicarb to NS irrigation is a simple and inexpensive approach that may assist in the dissolution of UA fragments produced during ureteroscopic laser lithotripsy. Further studies are needed to determine whether a clinical benefit exists.

Gallbladder Dynamics Before and After Extracorporeal Shock Wave Lithotripsy

Energy Technology Data Exchange (ETDEWEB)

Lee, Myung Hea; Suk, Jae Dong; Moon, Dae Hyuk; Kim, Myung Hwan; Min, Young Il [Asian Medical Center, Ulsan University College of Medicine, Seoul (Korea, Republic of)

1991-03-15

Extracorporeal shock wave lithotripsy (ESWI.) with adjunctive oral litholytic therapy has proven to be a useful treatment in selected patients with gallbladder stones. To study the effect of ESWL on gallbladder dynamics, {sup 99m}Tc-DISIDA hepatobiliary scintigraphy was done for 25 patients with symptomatic gallstones and 10 normal controls. Of these 25 patients, 15 were treated with ESWL and adjunctive oral litholytic agents (ESWL group) and 10 were treated only with oral litholytic agents (UDCA group). After overnight fast and gallbladder visualization on a routine hepatobiliary scintigraphy with 7 mCi of {sup 99m}Tc-DISIDA, subjects were given fatty meal and imaged with a gamma camera interfaced to a computer (I frame/minute for 70 minutes). A gallbladder time-activity curve was generated and latent period (LP), ejection period (EP), ejection fraction (EF) and ejection rate (ER) were calculated, ESWL group were studied before, l day after and 2 weeks after ESWL, and UDCA group were studied before and 2 weeks after starting oral medication Mean basal EF was significantly reduced in patients but other parameters were not reduced. In ESlVL group, mean EF and mean ER at 1 day after ESWL were reduced. In 3 of them, gallbladder was not visualized at all. Two weeks after ESWL, however, all parameters were recovered to basal level. In UDCA group, all parameters were not changed significantly during medication. We can conclude that ESWL has such immediate adverse effect on gallbladder dynamics as reducing contractility and nonvisualization of gallbladder but it has no long-term effect.

Percutaneous nephrolithotomy vs. extracorporeal shockwave lithotripsy for treating a 20-30 mm single renal pelvic stone.

Science.gov (United States)

Hassan, Mohammed; El-Nahas, Ahmed R; Sheir, Khaled Z; El-Tabey, Nasr A; El-Assmy, Ahmed M; Elshal, Ahmed M; Shokeir, Ahmed A

2015-09-01

To compare the efficacy, safety and cost of extracorporeal shockwave lithotripsy (ESWL) and percutaneous nephrolithotomy (PNL) for treating a 20-30 mm single renal pelvic stone. The computerised records of patients who underwent PNL or ESWL for a 20-30 mm single renal pelvic stone between January 2006 and December 2012 were reviewed retrospectively. Patients aged PNL. The re-treatment rate (75% vs. 5%), the need for secondary procedures (25% vs. 4.7%) and total number of procedures (three vs. one) were significantly higher in the ESWL group (P PNL group (95% vs. 75%, P PNL (US$ 1120 vs. 490; P PNL was more effective than ESWL for treating a single renal pelvic stone of 20-30 mm. However, ESWL was associated with fewer complications and a lower cost.

Extracorporeal shock wave lithotripsy for urinary stones

International Nuclear Information System (INIS)

Shinn, Kyung Sub; Kim, Hyun; Byun, Jae Young; Lee, Myung Hee; Bahk, Yong Whee; Park, Yong Hyun

1988-01-01

Extracorporeal shock wave lithotripsy (ESWL) is a new noninvasive treatment modality for urinary stones, and it sometimes is to necessitate endourologic techniques. ESWL with an Edap lithotripter which uses piezo-electric elements, was performed in 142 cases (130 patients) with urinary stones including 68 in calices, 30 in pelves, and 44 in ureters. Technical factors were 100 storages at 5 to 10 pulse rates/sec and 70-100% adjustable power for about 60 minutes (15-90) for renal stones, and 200 storages at 20 pulse rates/sec and 100% adjustable power for about 60 minutes for ureteral stones in a single treatment under stone localization by 5 MHz ultrasonic sector scanner. All patients were treated at Kangnam St.Mary's Hospital of Catholic University Medical College during the 5 months period from May 1, 1987. Every patient had pre-treatment chest, plain abdomen, intravenous urogram and ultrasonogram studies and post-treatment follow-up abdominal radiograms in 1 to 3 months after ESWL.The overall success rate of ESWL in 142 cases was 94.4%. Eight out of 142 cases were successful. Thus, 134 cases were analysed. Of these, 58 cases (43.3%) received one treatment, 33 cases (24.6%) two treatments, 16 cases (11.9%) three treatments and 27 cases (20.2%) more than four treatments. Renal stones were more successfully treated (98.0%) than ureteral stones (88.1%), and calyceal stones presented the highest success rate (98.5%). The stones as small as 5 to 10 mm in size were easily fragmented and the stones of round of oval shape were more easily pulverized than those of staghorn or amorphous shape. The adjunctive endourlogic techniques such as percutaneous nephrostomy, ureteral catheterization or internal ureteral stenting with a double pigtail catheter were required in 17 cases (11.9%). Complications of ESWL for urolithiasis included hematuria (84.5%), flank pain (8.5%) and fever (5.6%), which were controlled without specific treatment. ESWL using ultrasonic localization was

Extracorporeal shock wave lithotripsy for urinary stones

Energy Technology Data Exchange (ETDEWEB)

Shinn, Kyung Sub; Kim, Hyun; Byun, Jae Young; Lee, Myung Hee; Bahk, Yong Whee; Park, Yong Hyun [Kangnam St. Mary' s Hospital, Catholic University Medical College, Seoul (Korea, Republic of)

1988-06-15

Extracorporeal shock wave lithotripsy (ESWL) is a new noninvasive treatment modality for urinary stones, and it sometimes is to necessitate endourologic techniques. ESWL with an Edap lithotripter which uses piezo-electric elements, was performed in 142 cases (130 patients) with urinary stones including 68 in calices, 30 in pelves, and 44 in ureters. Technical factors were 100 storages at 5 to 10 pulse rates/sec and 70-100% adjustable power for about 60 minutes (15-90) for renal stones, and 200 storages at 20 pulse rates/sec and 100% adjustable power for about 60 minutes for ureteral stones in a single treatment under stone localization by 5 MHz ultrasonic sector scanner. All patients were treated at Kangnam St.Mary's Hospital of Catholic University Medical College during the 5 months period from May 1, 1987. Every patient had pre-treatment chest, plain abdomen, intravenous urogram and ultrasonogram studies and post-treatment follow-up abdominal radiograms in 1 to 3 months after ESWL.The overall success rate of ESWL in 142 cases was 94.4%. Eight out of 142 cases were successful. Thus, 134 cases were analysed. Of these, 58 cases (43.3%) received one treatment, 33 cases (24.6%) two treatments, 16 cases (11.9%) three treatments and 27 cases (20.2%) more than four treatments. Renal stones were more successfully treated (98.0%) than ureteral stones (88.1%), and calyceal stones presented the highest success rate (98.5%). The stones as small as 5 to 10 mm in size were easily fragmented and the stones of round of oval shape were more easily pulverized than those of staghorn or amorphous shape. The adjunctive endourlogic techniques such as percutaneous nephrostomy, ureteral catheterization or internal ureteral stenting with a double pigtail catheter were required in 17 cases (11.9%). Complications of ESWL for urolithiasis included hematuria (84.5%), flank pain (8.5%) and fever (5.6%), which were controlled without specific treatment. ESWL using ultrasonic localization

Control of acoustic cavitation with application to lithotripsy

Science.gov (United States)

Bailey, Michael Rollins

Control of acoustic cavitation, which is sound-induced growth and collapse of bubbles, is the subject of this dissertation. Application is to extracorporeal shock wave lithotripsy (ESWL), used to treat kidney stones. Cavitation is thought to help comminute stones yet may damage tissue. Can cavitation be controlled? The acoustic source in a widely used clinical lithotripter is an electrical spark at the near focus of an underwater ellipsoidal reflector. To control cavitation, we used rigid reflectors, pressure release reflectors, and pairs of reflectors aligned to have a common focus and a controlled delay between sparks. Cavitation was measured with aluminum foil, which was placed along the axis at the far focus of the reflector(s). Collapsing bubbles pitted the foil. Pit depth measured with a profilometer provided a relative measure of cavitation intensity. Cavitation was also measured with a focused hydrophone, which detected the pressure pulse radiated in bubble collapse. Acoustic pressure signals produced by the reflectors were measured with a PVdF membrane hydrophone, digitally recorded, and input into a numerical version of the Gilmore equation (F. R. Gilmore, 'The growth or collapse of a spherical bubble in a viscous compressible liquid,' Rep#26-4, California Institute of Technology, Pasadena (1952), pp.1-40.). Maximum pressure produced in a spherical bubble was calculated and employed as a relative measure of collapse intensity. Experimental and numerical results demonstrate cavitation can be controlled by an appropriately delayed auxiliary pressure pulse. When two rigid-reflector pulses are used, a long interpulse delay (150-200 μs) of the second pulse 'kicks' the collapsing bubble and intensifies cavitation. Foil pit depth and computed pressure three times single pulse values were obtained. Conversely, a short delay (ESWL.

Details management in the application of percutaneous nephroscope holmium laser lithotripsy%细节管理在经皮肾镜钬激光碎石术中的应用研究

Institute of Scientific and Technical Information of China (English)

王地萍; 张红芹

2014-01-01

目的：观察细节管理在经皮肾镜钬激光碎石术中的应用效果。方法：通过对56例患者进行经皮肾镜钬激光碎石的手术配合和对其围手术期的护理，总结出手术各个环节的护理要点。结果：56例手术患者中，一例中转切开取石，其余55例均碎石成功，效果非常满意，无并发症发生。结论：经皮肾镜钬激光碎石术具有出血少，创伤小，痛苦少，住院时间短、病人恢复快等优点，做好护理细节管理是保证手术顺利完成的重要条件。%Objective:To observe the details of the management in the application of percutaneous nephroscope holmium laser lithotripsy. Methods:By means of 56 patients with percutaneous nephroscope holmium laser lithotrip-sy procedure and the perioperative nursing, sums up the operation nursing key points of each part. Results:56 pa-tients with surgery, in case of transit the stones cut, the remaining 55 cases of gravel, effect is very satisfactory, no complications occurred. Conclusion: Percutaneous nephroscope holmium laser lithotripsy with less bleeding, small trauma, less pain, shorter hospitalization time and patients recover fast, do a good job in nursing detail management is vital to ensure that operation is completed.

Flexible Bronchoscopy.

Science.gov (United States)

Miller, Russell J; Casal, Roberto F; Lazarus, Donald R; Ost, David E; Eapen, George A

2018-03-01

Flexible bronchoscopy has changed the course of pulmonary medicine. As technology advances, the role of the flexible bronchoscope for both diagnostic and therapeutic indications is continually expanding. This article reviews the historical development of the flexible bronchoscopy, fundamental uses of the flexible bronchoscope as a tool to examine the central airways and obtain diagnostic tissue, and the indications, complications, and contraindications to flexible bronchoscopy. Copyright © 2017 Elsevier Inc. All rights reserved.

Assessment of Extracorporeal Shock Wave Lithotripsy (ESWL) Therapeutic Efficiency in Urolithiasis.

Science.gov (United States)

Tomescu, P; Pănuş, A; Mitroi, G; Drăgoescu, O; Stoica, L; Dena, S; Enache, E

2009-01-01

Extracorporeal shock wave lithotripsy (ESWL) revolutionized the treatment of urolithiasis and gradually became the favorite treatment option so that today it is considered to be the first line of treatment for more than 75% of the patients with urolithiasis. The purpose of this study was the assessment of the therapeutic efficiency, complications and limitations of ESWL in urolithiasis in the initial experience using a third generation electromagnetic lithotripter.  Between 2007 and 2008 we performed ESWL for 167 patients with urolithiasis. We recorded 92 patients with single stone (55.1%) and 72 with multiple lithiasis (44.9%). Stone size varied between 7 and 24 mm with an average of 12.3±7.1 mm. Radioopac stones were found in 104 patients (62.3%) while radiolucent stones in 63 only (37.6%).    Complete stone disintegration and clearance was achieved in most cases (86.2%). Complications were mostly minor and rare (transitory haematuria, renal colic). Severe complications (renal hematoma, steinstrasse) were diagnosed for a limited number of patients (3.6%) and their management was mostly nonsurgical or minimally invasive (retrograde ureteroscopy). ESWL is therefore the first line of treatment for urolithiasis with stone size smaller than 2.5 cm. It has an efficiency rate above 85%, low procedure time, high safety and good tolerability (new generation lithotripters do not require anesthesia) and minimal complications.

The effect of extracorporeal shock wave lithotripsy on kidney and adjacent tissue detected by magnetic resonance imaging

International Nuclear Information System (INIS)

Saiko, Yasushi; Hirose, Tomonobu; Yoshida, Masahiko; Saito, Isao

1995-01-01

Etracorporeal shock wave lithotripsy (ESWL) using YACHIYODA SZ1 was performed on 12 patients with renal stones and the effect on the kidney and adjacent tissue was evaluated by magnetic resonance imaging(MRI) before and after treatment. Some changes were seen in 6 of the 12 (50%) patients; perirenal fluid collection in 2 of the 12 (16.7%) patients, subcapsular hematoma in 2 of the 12 (16.7%) patients, renal enlargement in 5 of the 12 (31.3%) patients, increased signal intensity in perirenal tissue in 6 of the 12 (50%) patients, and loss of the corticomedullary junction in 2 out of 9 patients (22%). These findings indicated fewer changes in the kidney after ESWL using YACHIYODA SZ1 than in the other reports. MRI is also concluded to be effective to detect the changes of the kidney after ESWL. (author)

The effect of extracorporeal shock wave lithotripsy on kidney and adjacent tissue detected by magnetic resonance imaging

Energy Technology Data Exchange (ETDEWEB)

Saiko, Yasushi; Hirose, Tomonobu; Yoshida, Masahiko; Saito, Isao [Tokyo Kyosai Hospital (Japan)

1995-08-01

Etracorporeal shock wave lithotripsy (ESWL) using YACHIYODA SZ1 was performed on 12 patients with renal stones and the effect on the kidney and adjacent tissue was evaluated by magnetic resonance imaging(MRI) before and after treatment. Some changes were seen in 6 of the 12 (50%) patients; perirenal fluid collection in 2 of the 12 (16.7%) patients, subcapsular hematoma in 2 of the 12 (16.7%) patients, renal enlargement in 5 of the 12 (31.3%) patients, increased signal intensity in perirenal tissue in 6 of the 12 (50%) patients, and loss of the corticomedullary junction in 2 out of 9 patients (22%). These findings indicated fewer changes in the kidney after ESWL using YACHIYODA SZ1 than in the other reports. MRI is also concluded to be effective to detect the changes of the kidney after ESWL. (author).

Extracorporeal shock wave lithotripsy (ESWL) monotherapy in children: Predictors of successful outcome.

Science.gov (United States)

Alsagheer, G; Abdel-Kader, M S; Hasan, A M; Mahmoud, O; Mohamed, O; Fathi, A; Abass, M; Abolyosr, A

2017-10-01

Although extracorporeal shock wave lithotripsy (ESWL) is the first choice for pediatric renal calculi ESWL. A prospective study including 100 children with renal stone burden ESWL at the present institution. The success rate after the first session was analyzed, and the predictors of success were investigated. The success of ESWL monotherapy was defined by absence of any residual fragments after 3 months, on non-contrast spiral computerized tomography (NCCT) scan, without need of any additional intervention. Between January 2013 and October 2015, 100 children were treated with a Dornier Gemini lithotripter at the present institution. The mean patients age and stone size were 6 years (range: 1.8-14) and 13.1 mm (range: 6-20), respectively. After one session, 47% of patients showed complete clearance 3 months postoperative, those patients versus those who required an additional session or auxiliary procedures were younger in age, with smaller stone size and lower density. On multivariate analysis, only patient age was an independent predictor of success (odds ratio (OR) 0.9; P ESWL monotherapy: not only did children respond better than adults, but age was also an independent predictor within the pediatric group. Copyright © 2017 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.

Impacted Anterior Urethral Calculus Complicated by a Stone-containing Diverticulum in an Elderly Man: Outcome of Transurethral Lithotripsy without Resection of the Diverticulum

Directory of Open Access Journals (Sweden)

Tie Zhou

2013-09-01

Full Text Available Introduction The prevalence of lower urinary tract symptoms (LUTS is about 20% in men aged 40 or above. Other than benign prostatic hyperplasia (BPH, urethral diverticulum or calculus is not uncommon for LUTS in men. Surgical treatment is often recommended for urethral diverticulum or calculus, but treatment for an impacted urethral calculus complicated by a stone-containing diverticulum is challenging. Materials and Methods An 82-year-old man had the persistence of LUTS despite having undergone transurethral resection of prostate for BPH. Regardless of treatment with broad spectrum antibiotics and an α-blocker, LUTS and post-void residual urine volume (100 mL did not improve although repeated urinalysis showed reduction of WBCs from 100 to 10 per high power field. Further radiology revealed multiple urethral calculi and the stone configuration suggested the existence of a diverticulum. He was successfully treated without resecting the urethral diverticulum; and a new generation of ultrasound lithotripsy (EMS, Nyon, Switzerland through a 22F offset rigid Storz nephroscope (Karl Storz, Tuttingen, Germany was used to fragment the stones. Results The operative time was 30 minutes and the stones were cleanly removed. The patient was discharged after 48 hours with no immediate complications and free of LUTS during a 2 years follow-up. Conclusions When the diverticulum is the result of a dilatation behind a calculus, removal of the calculus is all that is necessary. Compared with open surgery, ultrasound lithotripsy is less invasive with little harm to urethral mucosa; and more efficient as it absorbs stone fragments while crushing stones.

Impacted anterior urethral calculus complicated by a stone-containing diverticulum in an elderly man: outcome of transurethral lithotripsy without resection of the diverticulum.

Science.gov (United States)

Zhou, Tie; Chen, Guanghua; Zhang, Wei; Peng, Yonghan; Xiao, Liang; Xu, Chuangliang; Sun, Yinghao

2013-01-01

The prevalence of lower urinary tract symptoms (LUTS) is about 20% in men aged 40 or above. Other than benign prostatic hyperplasia (BPH), urethral diverticulum or calculus is not uncommon for LUTS in men. Surgical treatment is often recommended for urethral diverticulum or calculus, but treatment for an impacted urethral calculus complicated by a stone-containing diverticulum is challenging. An 82-year-old man had the persistence of LUTS despite having undergone transurethral resection of prostate for BPH. Regardless of treatment with broad spectrum antibiotics and an α-blocker, LUTS and post-void residual urine volume (100 mL) did not improve although repeated urinalysis showed reduction of WBCs from 100 to 10 per high power field. Further radiology revealed multiple urethral calculi and the stone configuration suggested the existence of a diverticulum. He was successfully treated without resecting the urethral diverticulum; and a new generation of ultrasound lithotripsy (EMS, Nyon, Switzerland) through a 22F offset rigid Storz nephroscope (Karl Storz, Tuttingen, Germany) was used to fragment the stones. The operative time was 30 minutes and the stones were cleanly removed. The patient was discharged after 48 hours with no immediate complications and free of LUTS during a 2 years follow-up. When the diverticulum is the result of a dilatation behind a calculus, removal of the calculus is all that is necessary. Compared with open surgery, ultrasound lithotripsy is less invasive with little harm to urethral mucosa; and more efficient as it absorbs stone fragments while crushing stones.

Laparoscopic - assisted transpyelic rigid nephroscopy - simple alternative when flexible ureteroscopy is not available

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Marcos Tobias-Machado

Full Text Available ABSTRACT Introduction: In special situations such as malrotated or ectopic kidneys and UPJ stenosis treatment of renal lithiasis can be challenging. In these rare cases laparoscopy can be indicated. Objective: Describe the Laparoscopic-assisted rigid nephroscopy performed via transpyelic approach and report the feasibility. Patients and methods: We present two cases of caliceal lithiasis. The first is a patient that ESWL and previous percutaneous lithotripsy have failed, with pelvic kidney where laparoscopic dissection of renal pelvis was carried out followed by nephroscopy utilizing the 30 Fr rigid nephroscope to remove the calculus. Ideal angle between the major axis of renal pelvis and the rigid nephroscope to allow success with this technique was 60-90 grades. In the second case, the kidney had a dilated infundibulum. Results: The operative time was 180 minutes for both procedures. No significant blood loss or perioperative complications occurred. The bladder catheter was removed in the postoperative day 1 and Penrose drain on day 2 when patients were discharged. The convalescence was completed after 3 weeks. Patients were stone free without symptons in one year of follow-up. Conclusions: Laparoscopic-assisted rigid nephroscopy performed via tranpyelic approach can be done safely with proper patient selection and adherence to standard laparoscopic surgical principles. This approach is an alternative in cases where flexible endoscope is not available and when standard procedure is unlikely to produce a stone-free status.

On flexibility

OpenAIRE

Weiss, Christoph R.; Briglauer, Wolfgang

2000-01-01

By building on theoretical work by Mills and Schumann (1985) and Ungern-Sternberg (1990) this paper provides evidence on the determinants of two dimensions of flexibility, the flexibility in adjusting aggregate output over time (tactical flexibility) as well as the ability to switch quickly between products (operational flexibility). Econometric analysis of a sample of 40.000 farms in Upper-Austria for the period 1980 to 1990 suggests that larger full-time farms operated by younger, better ed...

Local anesthesia for extracorporeal shock wave lithotripsy: a study comparing eutetic mixture of local anesthetics cream and lidocaine infiltration

DEFF Research Database (Denmark)

Honnens de Lichtenberg, M; Miskowiak, J; Mogensen, P

1992-01-01

A study of the anesthetic efficacy of a eutetic mixture of local anesthetics (EMLA cream) versus lidocaine infiltration in extracorporeal shock wave lithotripsy (ESWL) was done. A total of 46 patients had 30 gm. of EMLA cream applied to the skin over the kidney and 45 had subcutaneous infiltration...... anesthesia with 20 ml. 1% lidocaine with epinephrine. All patients received an intravenous dose of morphine just before ESWL. The patients were comparable with regard to age, sex, weight, morphine dosage, number of shock waves given and duration of treatment. Median pain score and the amount of supplementary...... analgesics were not significantly different between the 2 groups. There were no significant differences between the groups with regard to post-ESWL skin changes. Therefore, EMLA cream can be recommended for ESWL provided it is applied correctly....

Influence of the renal lower pole anatomy and mid-renal-zone classification in successful approach to the calices during flexible ureteroscopy.

Science.gov (United States)

Marroig, Bruno; Frota, Rodrigo; Fortes, Marco A; Sampaio, Francisco J; Favorito, Luciano Alves

2016-04-01

The aim of this paper is to analyze if the anatomy type of the collector system (CS) limits the accessibility of flexible ureteroscopy (FUR) in the lower pole. We analyzed the pyelographies of 51 patients submitted to FUR and divided the CS into four groups: A1-kidney midzone (KM) drained by minor calices (Mc) that are dependent on the superior or on the inferior caliceal groups; A2-KM drained by crossed calices; B1-KM drained by a major caliceal group independent both of the superior and inferior groups, and B2-KM drained by Mc entering directly into the renal pelvis. We studied the number of calices, the angle between the lower infundibulum and renal pelvis, and the angle between the lower infundibulum and the inferior Mc. With the use of a flexible ureteroscope, the access attempt was made to all of lower pole calices. Averages were statistically compared using the ANOVA and Unpaired T test (p kidneys of A1 (27.45 %); 4 of A2 (7.84 %); 17 of B1 (33.33 %); and 16 of B2 (31.37 %). The LIP was >90° in 31 kidneys (60.78 %) and between 61° and 90° in 20 kidneys (39.22 %). We did not find angles smaller than 60°. The group A1 presented 48 Mc and the UF was able to access 42 (87.5 %); the group A2 had 11 Mc and the UF was able to access 7 (63.64 %); the group B1 had 48 Mc and the UF was able to access 41 (85.42 %) and in group B2 we observed 41 Mc and the UF could access 35 (85.36 %). There was no statistical difference in the accessibility between the groups (p = 0.2610). Collecting system with kidney midzone drained by crossed calices presented the lower accessibility rate during FUR.

Balance and flexibility.

Science.gov (United States)

2003-12-01

The 'work-life balance' and flexible working are currently key buzz terms in the NHS. Those looking for more information on these topics should visit Flexibility at www.flexibility.co.uk for a host of resources designed to support new ways of working, including information on flexible workers and flexible rostering, the legal balancing act for work-life balance and home working.

A litotripsia extracorpórea no tratamento de cálculos urinários em crianças Extracorporeal lithotripsy for the treatment of urolithiasis in children

Directory of Open Access Journals (Sweden)

Ricardo J. Duarte

2002-09-01

Full Text Available Objetivo: cálculos urinários atingem de 5 a 10% da população em alguma fase da vida. Destes casos, somente 2 a 3% são crianças. O tratamento da litíase urinária na faixa pediátrica, com o uso de métodos minimamente invasivos, representa uma alternativa cada vez mais atraente. O presente trabalho objetiva apresentar resultados de litotripsia extracorpórea como tratamento minimamente invasivo de litíase urinária na infância. Métodos: no período de setembro de 1991 a setembro de 2000, foram tratadas e acompanhadas 87 crianças, sendo que seis delas tinham dois cálculos; portanto foram tratados 93 cálculos urinários. Foi utilizado o equipamento de litotripsia extracorpórea por ondas de choque, da Dornier-Philips. Resultados: os cálculos piélicos, caliciais superiores e médios foram fragmentados e eliminados na porcentagem de 87,7% e 77,8%, respectivamente. Os cálculos localizados no cálice inferior foram eliminados em 64,7%. Dos três casos de cálculo coraliforme, somente um ficou livre do cálculo (33,3%. Os dez pacientes com cálculo ureteral ficaram livres de litíase (100%. Os cálculos vesicais foram tratados e eliminados em 60% dos casos. Conclusão: a litotripsia extracorpórea demonstrou ser uma forma eficiente de tratamento de cálculos piélicos, caliciais, ureterais e vesicais em crianças. Cálculos coraliformes não tiveram bons resultados quando tratados por meio de litotripsia extracorpórea. Os resultados deste método foram influenciados pela localização e tamanho dos cálculos.Objective: urolithiasis affects between five and 10% of the human population during their lifetime, only 2-3% of whom are children. Therapy of urolithiasis in the pediatric age group with minimally invasive methodology represents an attractive alternative. This study presents results of extracorporeal shockwave lithotripsy, a minimally invasive methodology, for the treatment of urolithiasis in children. Methods: in the period

Stone size and quality of life: A critical evaluation after extracorporeal shock wave lithotripsy

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Cahit Sahin

2015-09-01

Full Text Available Objectives: To evaluate the quality of life (QoL of the patients after extracorporeal shockwave lithotripsy (ESWL on a treated stone size related basis. Methods: 90 patients undergoing ESWL for kidney stones were divided into three groups; Group 1 (n: 30, ≤ 10mm, Group 2 (n: 28, 11 mm- ≤ 20 mm and Group 3 (n: 32, 20- 25 mm. During 3- months follow-up, outcome of the procedure, number of cases with emergency department visits, analgesic required, re-tretatment rates, additional procedures and the changes in the QoL were evaluated. Results: the number of emergency department visits and mean analgesic need; re-treatment rates and additional procedures were significantly higher in Group 3. Evaluation of the QoL scores in three groups showed that cases with larger stone still had lower scores during 3-month evaluation. Conclusions: Stone size could help us to predict the possible impact of ESWL on the QoL and depending on the size of the stone treated, a well planned indication and effective management possibly by an experienced urologist could limit the changes in the QoL of the patients.

Effect of Diuretics on Ureteral Stone Therapy with Extracorporeal Shock Wave Lithotripsy

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Zomorrodi A

2008-01-01

Full Text Available To evaluate the effect of diuretics on ureteral stone fragmentation and clearance during therapy with extra corporeal shock wave lithotripsy (ESWL, we studied 87 patients with ureteral stone at different levels and treated with ESWL. The patients were randomized into two groups treated by standard ESWL; the treatment protocol included 3500 shock wave per patient in each session, energy of the shock in two groups was 13 to 9 kv per patient, and the number of sessions was 3 per patient. The first group included 43 patients who received only ESWL, while the second group of 44 patients received as well 40 mg of furosemide. Stone fragmentation rate was 81% and 93.1% and stone clearance rate was 68.2% and 88.4% for the first and the second groups, respectively. With diuretics, fragmentation was18.8% more in the middle ureteral stones, 16.9% more in the upper tract stones, and 5.4% more in the distal stones. Moreover, clearance of fragmented stones was 38%, 28%, 15.4% more at middle and upper and distal ureteral stone, respectively. We conclude that the stone fragmentation and clearance were higher with ESWL and diuretics than without diuresis. Diuresis is safe and has some advantage at increasing the effect of ESWL on ureteral stones especially the middle ureteral calculi.

Has the pelvic renal stone position inside the upper loop of JJ stent any influence on the extracorporeal shock wave lithotripsy results?

Science.gov (United States)

Pricop, Catalin; Serban, Dragomir N; Serban, Ionela Lacramioara; Cumpanas, Alin-Adrian; Gingu, Constantin-Virgil

2016-01-01

JJ stents are often encountered in patients with pelvic renal stones referred for shock wave lithotripsy, most of them being placed either for obstructive renal pelvic stones or for ureteric stones mobilized retrograde during the JJ stent insertion. The aim of the study was to determine whether the relative stone position in the upper loop of the JJ stent during extracorporeal shock wave lithotripsy (SWL) influences the efficiency of the procedure. The study was designed as a prospective cohort study on 162 patients addressing the same urological department, with single renal pelvic stone (primary or mobilized to the renal pelvis during the insertion of JJ stent), smaller than 15 mm, with JJ stent, treated by SWL using a second generation spark gap lithotripter, 18 kV, 3000 waves/session. Patients were divided in three groups according to the relative position of the stone to the upper loop of the JJ stent as appears on plain X-ray: stone-inside-loop, loop-crossing-stone and stone-outside the loop. The SWL success rate was the primary outcome of the study. p Value, Chi square and Kruskal-Wallis tests were used for statistical analysis. For stone-inside-loop cases, SWL efficiency was 22.7 versus 42 % for all the other cases (p = 0.002). Other factors for decreased SWL success rate were: higher stone radio-opacity, larger JJ of stent and obese patients. Study limitation is represented by the relative small study group and by the evaluation of stone density using plain X-ray instead of computer tomography. For pelvic renal stones having the same density characteristics studied by plain X-ray, the SWL efficiency is lower in stone-inside-loop cases comparing with the other positions. The overall stone free rate for renal pelvic stones could be explained by the second generation lithotripter used for all procedures.

The Current Role of Endourologic Management of Renal Transplantation Complications

Directory of Open Access Journals (Sweden)

Brian D. Duty

2013-01-01

Full Text Available Introduction. Complications following renal transplantation include ureteral obstruction, urinary leak and fistula, urinary retention, urolithiasis, and vesicoureteral reflux. These complications have traditionally been managed with open surgical correction, but minimally invasive techniques are being utilized frequently. Materials and Methods. A literature review was performed on the use of endourologic techniques for the management of urologic transplant complications. Results. Ureterovesical anastomotic stricture is the most common long-term urologic complication following renal transplantation. Direct vision endoureterotomy is successful in up to 79% of cases. Urinary leak is the most frequent renal transplant complication early in the postoperative period. Up to 62% of patients have been successfully treated with maximal decompression (nephrostomy tube, ureteral stent, and Foley catheter. Excellent outcomes have been reported following transurethral resection of the prostate shortly after transplantation for patients with urinary retention. Vesicoureteral reflux after renal transplant is common. Deflux injection has been shown to resolve reflux in up to 90% of patients with low-grade disease in the absence of high pressure voiding. Donor-gifted and de novo transplant calculi may be managed with shock wave, ureteroscopic, or percutaneous lithotripsy. Conclusions. Recent advances in equipment and technique have allowed many transplant patients with complications to be effectively managed endoscopically.

Shockwave lithotripsy with music: Less painful and more satisfactory treatment.

Science.gov (United States)

Ordaz Jurado, D G; Budia Alba, A; Bahilo Mateu, P; Trassierra Villa, M; López-Acón, D; Boronat Tormo, F

2017-11-01

The objective of this study was to determine whether listening to music during a session of extracorporeal shockwave lithotripsy (ESWL) improves patients' pain. A simple, blind randomisation was undertaken of patients with kidney and ureter stones attending an ESWL session of 7,000 waves for the first time, between September and December 2014. One group was given music and the other was not. The age, gender, location of stones (kidney/ureter) were recorded and 2questionnaires: pre ESWL (questionnaire A) and postESWL (questionnaire B). Each questionnaire contained a question about anxiety and another question on pain on the Likert scale (0-10). Questionnaire B also had a question on satisfaction and comfort (Likert 0-10). Other variables included heart rate, respiratory rate, systolic and diastolic blood pressure on wave 2,000, 5,000 and 7,000, reason for halting the procedure, total pethidine (mg), secondary analgesia, energy (J) and frequency (Hz). Bivariate analysis using the Student's t-test, X 2 /Fisher test and a multiple linear regression model. The sample comprised 95 patients, with a mean age of 52 (±13) years, 35 (36.84%) females, 60 (63.2%) males. A total of 25 (26.3%) ureter stones and 70 (73.7%) kidney stones. A number of 42 (44.2%) patients were given music. There were no differences between the demographic variables or questionnaire A scores. Satisfaction and pain were better on questionnaire B with music. Music can reduce pain and improve patient satisfaction in ESWL treatment. More studies are required to confirm this effect. Copyright © 2017 AEU. Publicado por Elsevier España, S.L.U. All rights reserved.

Prognostic factors of success of extracorporeal shock wave lithotripsy (ESWL) in the treatment of renal stones.

Science.gov (United States)

Al-Ansari, Abdulla; As-Sadiq, Khalid; Al-Said, Sami; Younis, Nagy; Jaleel, Osama A; Shokeir, Ahmed A

2006-01-01

To evaluate the factors that affect the success rate of extracorporeal shock wave lithotripsy (ESWL) for treatment of renal stones. Between January 2000 and December 2003, 427 patients with single or multiple renal stones (ESWL monotherapy using Storz SL 20 lithotriptor. The results of treatment were evaluated after 3 months of follow-up. Treatment success was defined as complete clearance of the stones or presence of clinically insignificant residual fragments ESWL auxiliary procedures were required in 36 patients (8.4%). Post-ESWL complications were recorded in 16 patients (3.7%). Of the 10 prognostic factors studied, 5 had a significant impact on the success rate, namely: renal morphology, congenital anomalies, stone size, stone site and number of treated stones. Other factors including age, sex, nationality, stone nature (de novo or recurrent) and ureteric stenting had no significant impact on the success rate. The success rate of ESWL for the treatment of renal stones could be predicted by stone size, location and number, radiological renal features and congenital renal anomalies.

Flexible structured high-frequency film bulk acoustic resonator for flexible wireless electronics

International Nuclear Information System (INIS)

Zhou, Changjian; Shu, Yi; Yang, Yi; Ren, Tian-Ling; Jin, Hao; Dong, Shu-Rong; Chan, Mansun

2015-01-01

Flexible electronics have inspired many novel and very important applications in recent years and various flexible electronic devices such as diodes, transistors, circuits, sensors, and radiofrequency (RF) passive devices including antennas and inductors have been reported. However, the lack of a high-performance RF resonator is one of the key bottlenecks to implement flexible wireless electronics. In this study, for the first time, a novel ultra-flexible structured film bulk acoustic resonator (FBAR) is proposed. The flexible FBAR is fabricated on a flexible polyimide substrate using piezoelectric thin film aluminum nitride (AlN) for acoustic wave excitation. Both the shear wave and longitudinal wave can be excited under the surface interdigital electrodes configuration we proposed. In the case of the thickness extension mode, a flexible resonator with a working frequency as high as of 5.2325 GHz has been realized. The resonators stay fully functional under bending status and after repeated bending and re-flattening operations. This flexible high-frequency resonator will serve as a key building block for the future flexible wireless electronics, greatly expanding the application scope of flexible electronics. (paper)

Urinary Beta-2Microglobulin: An Indicator of Renal Tubular Damage after Extracorporeal Shock Wave Lithotripsy.

Science.gov (United States)

Nasseh, Hamidreza; Abdi, Sepideh; Roshani, Ali; Kazemnezhad, Ehsan

2016-12-08

This study aims to determine extracorporeal shock wave lithotripsy (ESWL)-induced renal tubular damageand the affecting factors by measuring urinary beta2microglobulin (β2M) excretion. This is a cross-sectional study conducted on 91 patients with renal stones who underwentESWL during 2012. Urinary beta2microglobulin was measured immediately before and after the procedure foreach patient and analyzed based on different variables to evaluate factors affecting ESWL-induced renal tubularinjury. Mean ± SD urinary beta2-microglobulin values, before and after ESWL were 0.08 ± 0.07 and 0.22 ± 0.71mg/dL respectively, the average difference between which was equal to 0.14 ± 0.07 mg/dL. These figures exhibiteda 166.66% rise in the urinary β2M concentration after ESWL which was statistically significant (P ESWL (P = .02) were predictive factors ofhigher post-ESWL urinary beta2-microglobulin excretion. Urinary excretion of beta2-microglobulin increased significantly immediately after ESWL. Thesechanges could indicate that ESWL is a contributing factor to renal tubular damage. It also seems that in patientswith hypertension and a previous history of ESWL the likelihood of this injury is higher than others.

Extracorporeal shock wave lithotripsy for gallbladder stones - an experimental and clinical study -

International Nuclear Information System (INIS)

Kim, Kun Sang; Park, Sil Moo; Lee, Jung Hyo; Kim, Young Goo; Song, Kounn Sik; Lee, Kwan Seh; Lee, Jong Beum; Kim, Sang Joon; Chang, Sun Taik

1988-01-01

Although many alternative treatment technics have been proposed recently for gallstone to substitute cholecystectomy, the extracorporeal shock wave lithotripsy (ESWL) for gallbladder stones has rarely been tried. We have carried out a series of experiments to evaluate how effective the ESWL for gallbladder stones in and how safe this procedure is. At first, in vitro shock were application was carried out to 10 gallbladder stones which were obtained from human gallbladder. Secondly, gallbladder stones were implanted to canine gallbladder and treated with shock wave. Lastly, a total of 41 volunteers with confirmed gallbladder stones were treated with shock wave and combined oral administration of ursodeoxycholic acid. In the in vitro experiment, all of the 10 gallstones were fragmented with variable firing rates and duration. In animal experiment, the implanted stones were successfully fragmented and the organs included in the pathway of shock wave were proved to be intact histologically. In human study, complete disappearance of gallstones was noted in 78.6% of patients with single radiolucent gallbladder stones, smaller than 2.5cm in the longest diameter. Two patients underwent cholecystectomy after ESWL due to sudden colic attack. One patient had experienced an episode of mild transient obstructive jaundice. It may be concluded that the ESWL for gallbladder stones is an effective and safe method of treatment of gallbladder stones in the selected cases, for example, small radiolucent stones, and the further study is needed to establish improved technology of the ESWL for gallbladder stones.

Extracorporeal shock wave lithotripsy for gallbladder stones - an experimental and clinical study -

Energy Technology Data Exchange (ETDEWEB)

Kim, Kun Sang; Park, Sil Moo; Lee, Jung Hyo; Kim, Young Goo; Song, Kounn Sik; Lee, Kwan Seh; Lee, Jong Beum; Kim, Sang Joon; Chang, Sun Taik [Chung-Ang University College of Medicine, Seoul (Korea, Republic of)

1988-08-15

Although many alternative treatment technics have been proposed recently for gallstone to substitute cholecystectomy, the extracorporeal shock wave lithotripsy (ESWL) for gallbladder stones has rarely been tried. We have carried out a series of experiments to evaluate how effective the ESWL for gallbladder stones in and how safe this procedure is. At first, in vitro shock were application was carried out to 10 gallbladder stones which were obtained from human gallbladder. Secondly, gallbladder stones were implanted to canine gallbladder and treated with shock wave. Lastly, a total of 41 volunteers with confirmed gallbladder stones were treated with shock wave and combined oral administration of ursodeoxycholic acid. In the in vitro experiment, all of the 10 gallstones were fragmented with variable firing rates and duration. In animal experiment, the implanted stones were successfully fragmented and the organs included in the pathway of shock wave were proved to be intact histologically. In human study, complete disappearance of gallstones was noted in 78.6% of patients with single radiolucent gallbladder stones, smaller than 2.5cm in the longest diameter. Two patients underwent cholecystectomy after ESWL due to sudden colic attack. One patient had experienced an episode of mild transient obstructive jaundice. It may be concluded that the ESWL for gallbladder stones is an effective and safe method of treatment of gallbladder stones in the selected cases, for example, small radiolucent stones, and the further study is needed to establish improved technology of the ESWL for gallbladder stones.

INSITU extracorporeal shock- wave lithotripsy as a primary treatment for ureteral stones

International Nuclear Information System (INIS)

Maghraby, Hisham

2003-01-01

The aim of the sudy was to evaluate the results ofextracorporeal shock-wave lithotripsy (ESWL) as a primary treatment for ureteral calculi at different levels. We treated 166 consecutive patients with solitary ureteral stones (73 at the upper, 4 at the middle and 89 at the lower ureter) by primary in situ ESWL on an outpatient basis. A maximum of three treatments were given individually before adopting ureteroscopy as an alternative treatment. The success rate was calculated on the basis of complete stone clearance and resolution of any associated obstruction. Re-treatment rates ,complications and time to complete stone clearence were recorded. Complete stone clearance was received in 152 patients (91.6%) after an average of 10.2 days ( range1-28). The average treatment rate was 1.3 sessions per patient. As whole groups, lower ureteral stones required more treatment sessions than those in the upper ureter , and the difference was statistically significant.However, differences in the final success rate and time to stone clearence were statistically nonsignificant. When stratified according to size, the success rate was lowest for lower ureteral stones >1 cm in diameter. We believe ESWL is a safe and simple non-invasive option of choice for most ureteral calculi at different levels. Ureteroscopy represents an alternative choice in case of ESWL failure, or in cases of larger stones in the lower ureter when it might be the first option. (author)

Holographic interferometric observation of shock wave focusing to extracorporeal shock wave lithotripsy

Science.gov (United States)

Takayama, Kazuyoshi; Obara, Tetsuro; Onodera, Osamu

1991-04-01

Underwater shock wave focusing is successfully applied to disintegrate and remove kidney stones or gallbladder stones without using surgical operations. This treatment is one of the most peaceful applications ofshock waves and is named as the Extracorporeal Shock Wave Lithotripsy. Ajoint research project is going on between the Institute ofFluid Science, Tohoku University and the School ofMedicine, Tohoku University. The paper describes a result of the fundamental research on the underwater shock wave focusing applied to the ESWL. Quantitatively to visualize the underwater shock waves, various optical flow visualization techniques were successfully used such as holographic interferometry, and shadowgraphs combined with Ima-Con high speed camera. Double exposure holographic interferometric observation revealed the mechanism of generation, propagation and focusing of underwater shock waves. The result of the present research was already used to manufacture a prototype machine and it has already been applied successfully to ESWL crinical treatments. However, despite of success in the clinical treatments, important fundamental questions still remain unsolved, i.e., effects of underwater shock wave focusing on tissue damage during the treatment. Model experiments were conducted to clarify mechanism of the tissue damage associated with the ESWL. Shock-bubble interactions were found responsible to the tissue damage during the ESWL treatment. In order to interprete experimental findings and to predict shock wave behavior and high pressures, a numerical simulation was carried. The numerical results agreed with the experiments.

Flexibility@Work 2013: yearly report on flexible labor and employment

NARCIS (Netherlands)

Berkhout, E.; Heyma, A.; Prins, J.

2013-01-01

There is no clear evidence that the strong growth in the share of flexible labor relations between 2002 and 2007 points at a worldwide trend towards a larger share of flexible labor at the expense of traditional open-ended labor contracts. The growth in flexible labor varies too much between

Abdominal fat distribution on computed tomography predicts ureteric calculus fragmentation by shock wave lithotripsy

Energy Technology Data Exchange (ETDEWEB)

Juan, Hsu-Cheng; Chou, Yii-Her [Kaohsiung Medical University Hospital, Department of Urology, Kaohsiung (China); Lin, Hung-Yu [Kaohsiung Medical University, Graduate Institute of Medicine, Kaohsiung (China); E-Da Hospital/ I-Shou University, Department of Urology, Kaohsiung (China); Yang, Yi-Hsin [Kaohsiung Medical University, Institute of Oral Health Sciences, Kaohsiung (China); Shih, Paul Ming-Chen [Kaohsiung Municipal Hsiao-Kang Hospital, Department of Radiology, Kaohsiung (China); Kaohsiung Medical University, Department of Radiology, Kaohsiung (China); Chuang, Shu-Mien [Yuh-Ing Junior College of Health Care and Management, Kaohsiung (China); Shen, Jung-Tsung [Kaohsiung Municipal Hsiao-Kang Hospital, Department of Urology, Kaohsiung (China); Juan, Yung-Shun [Kaohsiung Medical University Hospital, Department of Urology, Kaohsiung (China); Kaohsiung Medical University, Graduate Institute of Medicine, Kaohsiung (China); Kaohsiung Medical University, Department of Urology, Faculty of Medicine, Kaohsiung (China)

2012-08-15

To assess the effects of abdominal fat on shock wave lithotripsy (SWL). We used pre-SWL unenhanced computed tomography (CT) to evaluate the impact of abdominal fat distribution and calculus characteristics on the outcome of SWL. One hundred and eighty-five patients with a solitary ureteric calculus treated with SWL were retrospectively reviewed. Each patient underwent unenhanced CT within 1 month before SWL treatment. Treatment outcomes were evaluated 1 month later. Unenhanced CT parameters, including calculus surface area, Hounsfield unit (HU) density, abdominal fat area and skin to calculus distance (SSD) were analysed. One hundred and twenty-eight of the 185 patients were found to be calculus-free following treatment. HU density, total fat area, visceral fat area and SSD were identified as significant variables on multivariate logistic regression analysis. The receiver-operating characteristic analyses showed that total fat area, para/perirenal fat area and visceral fat area were sensitive predictors of SWL outcomes. This study revealed that higher quantities of abdominal fat, especially visceral fat, are associated with a lower calculus-free rate following SWL treatment. Unenhanced CT is a convenient technique for diagnosing the presence of a calculus, assessing the intra-abdominal fat distribution and thereby helping to predict the outcome of SWL. (orig.)

Abdominal fat distribution on computed tomography predicts ureteric calculus fragmentation by shock wave lithotripsy

International Nuclear Information System (INIS)

Juan, Hsu-Cheng; Chou, Yii-Her; Lin, Hung-Yu; Yang, Yi-Hsin; Shih, Paul Ming-Chen; Chuang, Shu-Mien; Shen, Jung-Tsung; Juan, Yung-Shun

2012-01-01

To assess the effects of abdominal fat on shock wave lithotripsy (SWL). We used pre-SWL unenhanced computed tomography (CT) to evaluate the impact of abdominal fat distribution and calculus characteristics on the outcome of SWL. One hundred and eighty-five patients with a solitary ureteric calculus treated with SWL were retrospectively reviewed. Each patient underwent unenhanced CT within 1 month before SWL treatment. Treatment outcomes were evaluated 1 month later. Unenhanced CT parameters, including calculus surface area, Hounsfield unit (HU) density, abdominal fat area and skin to calculus distance (SSD) were analysed. One hundred and twenty-eight of the 185 patients were found to be calculus-free following treatment. HU density, total fat area, visceral fat area and SSD were identified as significant variables on multivariate logistic regression analysis. The receiver-operating characteristic analyses showed that total fat area, para/perirenal fat area and visceral fat area were sensitive predictors of SWL outcomes. This study revealed that higher quantities of abdominal fat, especially visceral fat, are associated with a lower calculus-free rate following SWL treatment. Unenhanced CT is a convenient technique for diagnosing the presence of a calculus, assessing the intra-abdominal fat distribution and thereby helping to predict the outcome of SWL. (orig.)

Kidney damage in extracorporeal shock wave lithotripsy: a numerical approach for different shock profiles.

Science.gov (United States)

Weinberg, Kerstin; Ortiz, Michael

2009-08-01

In shock-wave lithotripsy--a medical procedure to fragment kidney stones--the patient is subjected to hypersonic waves focused at the kidney stone. Although this procedure is widely applied, the physics behind this medical treatment, in particular the question of how the injuries to the surrounding kidney tissue arise, is still under investigation. To contribute to the solution of this problem, two- and three-dimensional numerical simulations of a human kidney under shock-wave loading are presented. For this purpose a constitutive model of the bio-mechanical system kidney is introduced, which is able to map large visco-elastic deformations and, in particular, material damage. The specific phenomena of cavitation induced oscillating bubbles is modeled here as an evolution of spherical pores within the soft kidney tissue. By means of large scale finite element simulations, we study the shock-wave propagation into the kidney tissue, adapt unknown material parameters and analyze the resulting stress states. The simulations predict localized damage in the human kidney in the same regions as observed in animal experiments. Furthermore, the numerical results suggest that in first instance the pressure amplitude of the shock wave impulse (and not so much its exact time-pressure profile) is responsible for damaging the kidney tissue.

Comparison of propofol/fentanyl and ketamine anesthesia in children during extracorporeal shockwave lithotripsy

International Nuclear Information System (INIS)

Erden, A.; Artukoglu, F.; Gozacan, A.; Ozgen, S.

2007-01-01

Extracorporeal Shockwave Lithotripsy (ESWL) is an effective and safe way for treatment of upper urinary system stones. For pediatric patients, throughout ESWL, sufficient sedation and analgesia is needed to cope with the procedural pain. In this study, our goal was to compare 2 methods of intravenous anesthesia, applied to pediatric patients during ESWL. Forty patients, between 3 months and 15 years of age who were admitted to the Faculty of Medicine, Hacettepe University, Turkey between September 2003 to September 2004 with upper urinary system calculi were randomized into 2 groups. All patients received intranasal midazolam 0.3 mg/kg premedication. Group K received intravenous (iv) ketamine 2 mg/kg; Group PF received a bolus of iv propofol 3 mg/kg and iv fentanyl 1 ug/kg along with a propofol infusion of 1 mg/kg/hr throughout the procedure. Procedural, recovery and discharge times, incidences of intra and post-procedural complications were compared. Demographics, procedural and discharge times were similar in 2 groups. While recovery times and post-procedural complication incidence was higher for the Group K, intra-procedural complication incidence was higher for the Group PF. Although both protocols do not differ much according to ease of application and efficacy in providing sufficient analgesia for ESWL, they have their corresponding side effects and they can only be practiced safely by experienced anesthesiologists in a monitorized and well equipped setting. (author)

Lunar cycle may have an effect on Shock Wave Lithotripsy related pain outcome.

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Tokgöz, Hüsnü; Yalçınkaya, Soner; İslamoğlu, Ekrem; Karamık, Kaan; Tokgöz, Özlem; Savaş, Murat

2017-12-01

We tried to investigate the effects of lunar phase on Shock Wave Lithotripsy (SWL) related pain. In addition, correlation of various clinical parameters with the pain perception during SWL procedure, were also investigated. A total of 378 patients who underwent first SWL sessions for renal or ureteral stones were prospectively enrolled in the study. The degree of pain perception during the procedure was evaluated with 10-point visual analog scale (VAS) and pain questionnaires. The date of SWL was allocated to dates and times of lunar phases as: newmoon, waxing crescent, first quarter, waxing gibbus, fullmoon, waning gibbus, last quarter and waning gibbus. Mean VAS scores in first quarter (2,41±1,06) were significantly lower when compared to mean VAS scores in waning crescent (3,58±1,83) and waning gibbus (3,42±1,98) ( p=0,005 and 0,041 , respectively). No statistically significant differences were observed when other lunar phases were compared between each other. Mean pain scores were not affected from gender, age, body mass index (BMI) and stone characteristics (stone laterality, burden and location). SWL procedure performed in first quarter of the lunar phase may become less painful. To the best of our knowledge, this is the first study which evaluated the effect of lunar phase on post-SWL pain outcome. Thus, additional randomized studies with larger series may be more informative.

Patients' selection for treatment of caliceal diverticular stones with extracorporeal shock wave lithotripsy

International Nuclear Information System (INIS)

Lee, Won Hong; Lee, Hee Jeong; Son, Soon Yong; Kang, Seong Ho; Cho, Cheong Chan; Ryu, Meung Sun; Kim, Seung Kook

2001-01-01

Symptoms of caliceal diverticular stones are commonly associated with pain, recurrent urinary tract infection and hematuria. The aim of this study is to select the proper patient for the application of more successful extracorporeal shock wave lithotripsy(ESWL) as a treatment of caliceal diverticular stone. 16 patients with caliceal diverticular stones were treated with ESWL, and all patients had single caliceal diverticulum. The diagnosis of caliceal diverticulum with stones was made by intraveneous pyelography to all patients. On these intravenous pyelogram, we also classified diverticular type, whether the diverticular neck is connected with urinary tract patently, diverticular site and stone number and size. All patients were followed after ESWL by plain film of the kidneys, ureters and bladder and interviewed. Of all patients 44% was shown stone-free completely, also 83% was rendered symptom-free. All patients whose diverticular neck connected with urinary tract patently on the intraveneous pyelogram became stone-free. Of solitary stone 60% and multiple stones (more than 2) 17% became symptom-free. The patients with infection before ESWL 75% had residual stones, of these patients 33% had slightly flank pain, and 25% of patients with stones recurred become stone-free. We propose that more successful ESWL for patients with caliceal diverticular stones select satisfactory patients including that the diverticular neck is connected with urinary tract patently, solitary stone and no infection simultaneously

Analgesia for patients undergoing shockwave lithotripsy for urinary stones – a systematic review and meta-analysis

Directory of Open Access Journals (Sweden)

Omar M. Aboumarzouk

Full Text Available ABSTRACT Background Shock wave lithotripsy (SWL is the first line treatment modality for a significant proportion of patients with upper urinary tracts stones. Simple analgesics, opioids and non-steroidal anti-inflammatory drugs (NSAIDs are all suitable agents but the relative efficacy and tolerability of these agents is uncertain. Objectives To determine the efficacy of the different types of analgesics used for the control of pain during SWL for urinary stones. Materials and Methods We searched the Cochrane Renal Group’s Specialised Register, MEDLINE, EMBASE and also hand-searched reference lists of relevant articles (Figure-1. Randomised controlled trials (RCT’s comparing the use of any opioid, simple analgesic or NSAID during SWL were included. These were compared with themselves, each-other or placebo. We included any route or form of administration (bolus, PCA. We excluded agents that were used for their sedative qualities. Data were extracted and assessed for quality independently by three reviewers. Meta-analyses have been performed where possible. When not possible, descriptive analyses of variables were performed. Dichotomous outcomes are reported as relative risk (RR and measurements on continuous scales are reported as weighted mean differences (WMD with 95% confidence intervals. Results Overall, we included 9 RCTs (539 participants from 6 countries. Trial agents included 7 types of NSAIDs, 1 simple analgesic and 4 types of opioids. There were no significant differences in clinical efficacy or tolerability between a simple analgesic (paracetamol and an NSAID (lornoxicam. When comparing the same simple analgesic with an opioid (tramadol, both agents provided safe and effective analgesia for the purpose of SWL with no significant differences. There were no significant differences in pain scores between NSAIDs or opioids in three studies. Adequate analgesia could be achieved more often for opioids than for NSAIDs (RR 0.358; 95% CI

Piezoelectric extracorporeal lithotripsy of gallbladder stones: New inclusion criteria

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Han, Joon Koo; Choi, Byung Ihn; Shin, Yong Moon; Yoon, Yong Kyu; Yoon, Yong Bum; Park, Yong Hyun; Kim, Chu Wan; Han, Man Chung [Seoul National University College of Medicine, Seoul (Korea, Republic of)

1994-08-15

To establish the optimal inclusion criteria for the patients with gallbladder stones to extracorporeal shock wave lithotripsy(ESWL) by retrospectively analyzed our current results. Data obtained from 201 patients with gallbladder stones treated with ESWL and oral chemolytic agent from November 1988 to July 1992 were retrospectively analyzed. Ninety-six had radiolucent stones and 105 had radiopaque stones. We used piezoelectric lithotriptor(EDAP LT. 01) and there were no limitation in number of sessions or total number of shock waves. ESWL was repeated until the size of the largest fragment is smaller than 4 mm. Follow up ultrasound was done in every three months after the successful fragmentation. Average length of the follow up was 205 days. We analyzed the rate of successful fragmentation, number of shock waves needed to achieve successful fragmentation according to the size, number of stones as well as the presence of the calcification. Stone-free rate after 6 months was also calculated from all subgroups and compared to each other. The rate of successful fragmentation was 76.2% for radiolucent stones and 65.6% for radiopaque stones(p> 0.05) after 46,731 and 56,111 shock wave respectively(p > 0.05) The rate of successful fragmentation was highest in patients with single, radiolucent stone smaller than 2 cm(91.7%) followed by single radiolucent stone larger than 2 cm(83.3%), multiple calcified stones smaller than 2 cm (77.4%) and single calcified stone smaller than 2 cm(72.1%). The rate of complete stone clearance after 6 month follow-up was highest in patients with single radiolucent stone smaller than 2 cm (63.3%) and followed by multiple calcified stones smaller than 2 cm(37.3%), single calcified stone smaller than 2 cm(33.9%)(p < 0.05). To obtain better results with ESWL in patients with gallbladder stone, the authors propose a more strict inclusion criteria, which is the patient with a single, radiolucent stone smaller than 2 cm.

Piezoelectric extracorporeal lithotripsy of gallbladder stones: New inclusion criteria

International Nuclear Information System (INIS)

Han, Joon Koo; Choi, Byung Ihn; Shin, Yong Moon; Yoon, Yong Kyu; Yoon, Yong Bum; Park, Yong Hyun; Kim, Chu Wan; Han, Man Chung

1994-01-01

To establish the optimal inclusion criteria for the patients with gallbladder stones to extracorporeal shock wave lithotripsy(ESWL) by retrospectively analyzed our current results. Data obtained from 201 patients with gallbladder stones treated with ESWL and oral chemolytic agent from November 1988 to July 1992 were retrospectively analyzed. Ninety-six had radiolucent stones and 105 had radiopaque stones. We used piezoelectric lithotriptor(EDAP LT. 01) and there were no limitation in number of sessions or total number of shock waves. ESWL was repeated until the size of the largest fragment is smaller than 4 mm. Follow up ultrasound was done in every three months after the successful fragmentation. Average length of the follow up was 205 days. We analyzed the rate of successful fragmentation, number of shock waves needed to achieve successful fragmentation according to the size, number of stones as well as the presence of the calcification. Stone-free rate after 6 months was also calculated from all subgroups and compared to each other. The rate of successful fragmentation was 76.2% for radiolucent stones and 65.6% for radiopaque stones(p> 0.05) after 46,731 and 56,111 shock wave respectively(p > 0.05) The rate of successful fragmentation was highest in patients with single, radiolucent stone smaller than 2 cm(91.7%) followed by single radiolucent stone larger than 2 cm(83.3%), multiple calcified stones smaller than 2 cm (77.4%) and single calcified stone smaller than 2 cm(72.1%). The rate of complete stone clearance after 6 month follow-up was highest in patients with single radiolucent stone smaller than 2 cm (63.3%) and followed by multiple calcified stones smaller than 2 cm(37.3%), single calcified stone smaller than 2 cm(33.9%)(p < 0.05). To obtain better results with ESWL in patients with gallbladder stone, the authors propose a more strict inclusion criteria, which is the patient with a single, radiolucent stone smaller than 2 cm

From novelty to the every-day: the evolution of ureteroscopy.

Science.gov (United States)

Ridyard, Douglas; Dagrosa, Lawrence; Pais, Vernon M

2016-12-01

Ureteroscopy revolutionized the surgical approach to the upper urinary tract, and is well recognized as a cornerstone of modern urology. Although now commonplace, ureteroscopic equipment and techniques were truly revolutionary. A review of the innovations and innovators that developed ureteroscopic surgery sets the stage for a more thorough understanding of what can be done ureteroscopically, and may additionally better inform what limitations remain. Given that future advancements in urologic therapy will be dependent upon a similar pursuit of paradigm shifting improvements in disease management, an overview of the development of modern ureteroscopy may inspire such change.

Dynamic Model of a Rotating Flexible Arm-Flexible Root Mechanism Driven by a Shaft Flexible in Torsion

Directory of Open Access Journals (Sweden)

S.Z. Ismail

2006-01-01

Full Text Available This paper presents a dynamic model of a rotating flexible beam carrying a payload at its tip. The model accounts for the driving shaft and the arm root flexibilities. The finite element method and the Lagrangian dynamics are used in deriving the equations of motion with the small deformation theory assumptions and the Euler-Bernoulli beam theory. The obtained model is a nonlinear-coupled system of differential equations. The model is simulated for different combinations of shaft and root flexibilities and arm properties. The simulation results showed that the root flexibility is an important factor that should be considered in association with the arm and shaft flexibilities, as its dynamics influence the motor motion. Moreover, the effect of system non-linearity on the dynamic behavior is investigated by simulating the equivalent linearized system and it was found to be an important factor that should be considered, particularly when designing a control strategy for practical implementation.

The outcome of extracorporeal shockwave lithotripsy for renal pelvic stone with and without JJ stent--a comparative study.

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Mohayuddin, Nazim; Malik, Hamad Afzal; Hussain, Manzoor; Tipu, Salman Ahmed; Shehzad, Asad; Hashmi, Altaf; Naqvi, Syed Ali Anwar; Rizvi, Syed Adibul Hasan

2009-03-01

To compare the outcome of Extra corporeal shockwave lithotripsy for a renal pelvic stone with and without JJ stent. A comparative cross sectional study was carried out at Sindh Institute of Urology and Transplantation from January 2007 to January 2008. Eighty patients with renal pelvic stone measuring 2cm +/- 2mm were selected for treatment with Extra Corporeal Shockwave Lithotripsy (ESWL). All of these patients were adults with normal renal function and had unilateral renal stones with negative urine cultures. Patients with renal failure and children were excluded. They were divided into two groups of 40 each. Group A patients underwent ESWL without a JJ stent and in Group B a JJ stent was placed before ESWL. SLX F2 electromagnetic ESWL machine was used to impart shock waves. 3000 shockwaves were given in a session. Both the groups were compared for renal colic, steinstrasse, fever, lower urinary tract symptoms (LUTS) emergency room visits and hospital admissions, stone clearance, number of ESWL sessions, auxilliary procedures, (percutaneous nephrostomy or ureterorenoscopy) and cost. Ureteric colic occurred in 13 (32.5%) patients in group A and in 3 (7.5%) patient in group B. Steinstrasse developed in 4 (10%) patients with out JJ stent and in 3 (7.5%) patients with JJ stent. Fever was encountered in 1 (2.5%) patient in group A and in 3 (7.5%) patient in group B. Mean emergency room visits were 2.1 per patient in group A and 0.7 per patient in group B. Stone clearance occurred in 33 (82.5%) patients in group A and 31 (77.5%) in group B. In group B lower urinary tract symptoms were found in 50% versus 20% in group A. Auxillary procedure was performed in one (2.5%) patient each in both groups. Pre ESWL JJ stenting for a 2 cm +/- 2 mm renal stone was not beneficial in terms of steinstrasse, fever, stone clearance and number of ESWL sessions. However ureteric colic was significantly less in the stented group. Lower urinary tract symptoms (LUTS) was also significantly

Global Sourcing Flexibility

DEFF Research Database (Denmark)

Ørberg Jensen, Peter D.; Petersen, Bent

2013-01-01

the higher costs (but decreased risk for value chain disruption) embedded in a more flexible global sourcing model that allows the firm to replicate and/or relocate activities across multiple locations. We develop a model and propositions on facilitating and constraining conditions of global sourcing...... sourcing flexibility. Here we draw on prior research in the fields of organizational flexibility, international business and global sourcing as well as case examples and secondary studies. In the second part of the paper, we discuss the implications of global sourcing flexibility for firm strategy...... and operations against the backdrop of the theory-based definition of the construct. We discuss in particular the importance of global sourcing flexibility for operational performance stability, and the trade-off between specialization benefits, emerging from location and service provider specialization, versus...

[Questions of terminology, systematization and grading of complications of contact ureteral lithotripsy].

Science.gov (United States)

Dutov, V V; Bazaev, V V; Mamedov, E A; Urenkov, S B; Podoinitsyn, A A

2017-07-01

To investigate the advantages and disadvantages of the current variants of systematization and grading of complications of contact ureteral lithotripsy (CULT) and develop a working classification of CULT complications. The study analyzed results of 545 fluoroscopy-guided endoscopic procedures performed at the MRRCI Clinic of Urology from 2008 to 2015 in 506 patients with ureterolithiasis. The proposed and implemented classification and terminology of CULT complications unifies the diagnostic and management algorithm. This tool is more systematic and structured than the classical classification and universal methods of systematization and grading of CULT complications (classifying CULT complications in "major" and "minor", PULS scale, Satava and Clavien-Dindo grading systems). Given the lack of clear grading of ureteral rupture, it was divided into amputation (two-level rupture) and avulsion (one-level rupture). Using such term as extravasation of the contrast media and/or migration of the stone outside of the ureter is groundless because these complications occur only after the perforation of the ureteral wall. Therefore, these conditions are complications not of CULT, but of the ureteral wall perforation. The ureteral perforation was classified into macro- and micro-perforation. The existing terminology, classification and grading of the CULT complications should undergo a more detailed analysis. None of the existing classifications of CULT complications afford them to be fully staged and systematized. The working classification of complications of CULT developed at the M.F. Vladimirsky MRRCI Clinic of Urology warrants a multi-center prospective study to validate it and investigate its effectiveness.

Percutaneous nephrolithotomy versus extracorporeal shock wave lithotripsy for moderate sized kidney stones.

Science.gov (United States)

Deem, Samuel; Defade, Brian; Modak, Asmita; Emmett, Mary; Martinez, Fred; Davalos, Julio

2011-10-01

To compare the outcomes of percutaneous nephrolithotomy (PNL) and extracorporeal shock wave lithotripsy (ESWL) for moderate sized (1-2 cm) upper and middle pole renal calculi in regards to stone clearance rate, morbidity, and quality of life. All patients diagnosed with moderate sized upper and middle pole kidney stones by computed tomography (CT) were offered enrollment. They were randomized to receive either ESWL or PNL. The SF-8 quality of life survey was administered preoperatively and at 1 week and 3 months postoperatively. Abdominal radiograph at 1 week and CT scan at 3 months were used to determine stone-free status. All complications and outcomes were recorded. PNL established a stone-free status of 95% and 85% at 1 week and 3 months, respectively, whereas ESWL established a stone-free status of 17% and 33% at 1 week and 3 months, respectively. Retreatment in ESWL was required in 67% of cases, with 0% retreatment in PNL. Stone location, stone density, and skin-to-stone distance had no impact on stone-free rates at both visits, irrespective of procedure. Patient-reported outcomes, including overall physical and mental health status, favored a better quality of life for patients who had PNL performed. PNL more often establishes stone-free status, has a more similar complication profile, and has similar reported quality of life at 3 months when compared with ESWL for moderate-sized kidney stones. PNL should be offered as a treatment option to all patients with moderate-sized kidney stones in centers with experienced endourologists. Copyright © 2011 Elsevier Inc. All rights reserved.

Plain radiography, renography, and 99mTc-DMSA renal scintigraphy before and after extracorporeal shock wave lithotripsy for urolithiasis

International Nuclear Information System (INIS)

Munck, O.; Gerquari, I.; Moeller, J.T.; Jensen, L.I.; Thomsen, H.S.

1992-01-01

Eighteen patients were evaluated before and 5 weeks after the first treatment with extracorporeal shock wave lithotripsy (ESWL) using abdominal plain radiography, 131 I-hippuran probe renography, and 99m Tc-dimercaptosuccinic acid scintigraphy. In 6 patients no urolithiasis was present on the post ESWL plain radiograph, in 7 the size had decreased, and in 5 the stone mass was unchanged. The renograms were within normal range in the 6 patients who were cured by ESWL, whereas this was the case for only 4 of the 12 who still had renal calculi. In 2 patients pelvic stones had descended into the ureter after ESWL, and the renograms indicated obstruction. Another 3 patients had ureteral stones, whereas in the remaining 7 patients only pelvic stones were found on the plain radiographs. In no patient did the scintigrams reveal scars. It is concluded that abdominal plain radiography of the urinary tract and probe renography are complementary and sufficient in the monitoring of patients with urolithiasis post ESWL. (orig.)

Endockscope: using mobile technology to create global point of service endoscopy.

Science.gov (United States)

Sohn, William; Shreim, Samir; Yoon, Renai; Huynh, Victor B; Dash, Atreya; Clayman, Ralph; Lee, Hak J

2013-09-01

Recent advances and the widespread availability of smartphones have ushered in a new wave of innovations in healthcare. We present our initial experience with Endockscope, a new docking system that optimizes the coupling of the iPhone 4S with modern endoscopes. Using the United States Air Force resolution target, we compared the image resolution (line pairs/mm) of a flexible cystoscope coupled to the Endockscope+iPhone to the Storz high definition (HD) camera (H3-Z Versatile). We then used the Munsell ColorChecker chart to compare the color resolution with a 0° laparoscope. Furthermore, 12 expert endoscopists blindly compared and evaluated images from a porcine model using a cystoscope and ureteroscope for both systems. Finally, we also compared the cost (average of two company listed prices) and weight (lb) of the two systems. Overall, the image resolution allowed by the Endockscope was identical to the traditional HD camera (4.49 vs 4.49 lp/mm). Red (ΔE=9.26 vs 9.69) demonstrated better color resolution for iPhone, but green (ΔE=7.76 vs 10.95), and blue (ΔE=12.35 vs 14.66) revealed better color resolution with the Storz HD camera. Expert reviews of cystoscopic images acquired with the HD camera were superior in image, color, and overall quality (P=0.002, 0.042, and 0.003). In contrast, the ureteroscopic reviews yielded no statistical difference in image, color, and overall (P=1, 0.203, and 0.120) quality. The overall cost of the Endockscope+iPhone was $154 compared with $46,623 for a standard HD system. The weight of the mobile-coupled system was 0.47 lb and 1.01 lb for the Storz HD camera. Endockscope demonstrated feasibility of coupling endoscopes to a smartphone. The lighter and inexpensive Endockscope acquired images of the same resolution and acceptable color resolution. When evaluated by expert endoscopists, the quality of the images overall were equivalent for flexible ureteroscopy and somewhat inferior, but still acceptable for flexible cystoscopy.

Conflicting flexibility

NARCIS (Netherlands)

De Jong, P.; Schaap, A.

2011-01-01

New buildings are designed for first users. For a sustainable approach there are many advantages in designing in flexibility and adjustability in order to enable and facilitate the other sequential users. For the first investor this flexibility is translated into improved exit values due to

Inter-vertebral flexibility of the ostrich neck: implications for estimating sauropod neck flexibility.

Science.gov (United States)

Cobley, Matthew J; Rayfield, Emily J; Barrett, Paul M

2013-01-01

The flexibility and posture of the neck in sauropod dinosaurs has long been contentious. Improved constraints on sauropod neck function will have major implications for what we know of their foraging strategies, ecology and overall biology. Several hypotheses have been proposed, based primarily on osteological data, suggesting different degrees of neck flexibility. This study attempts to assess the effects of reconstructed soft tissues on sauropod neck flexibility through systematic removal of muscle groups and measures of flexibility of the neck in a living analogue, the ostrich (Struthio camelus). The possible effect of cartilage on flexibility is also examined, as this was previously overlooked in osteological estimates of sauropod neck function. These comparisons show that soft tissues are likely to have limited the flexibility of the neck beyond the limits suggested by osteology alone. In addition, the inferred presence of cartilage, and varying the inter-vertebral spacing within the synovial capsule, also affect neck flexibility. One hypothesis proposed that flexibility is constrained by requiring a minimum overlap between successive zygapophyses equivalent to 50% of zygapophyseal articular surface length (ONP50). This assumption is tested by comparing the maximum flexibility of the articulated cervical column in ONP50 and the flexibility of the complete neck with all tissues intact. It is found that this model does not adequately convey the pattern of flexibility in the ostrich neck, suggesting that the ONP50 model may not be useful in determining neck function if considered in isolation from myological and other soft tissue data.

Inter-vertebral flexibility of the ostrich neck: implications for estimating sauropod neck flexibility.

Directory of Open Access Journals (Sweden)

Matthew J Cobley

Full Text Available The flexibility and posture of the neck in sauropod dinosaurs has long been contentious. Improved constraints on sauropod neck function will have major implications for what we know of their foraging strategies, ecology and overall biology. Several hypotheses have been proposed, based primarily on osteological data, suggesting different degrees of neck flexibility. This study attempts to assess the effects of reconstructed soft tissues on sauropod neck flexibility through systematic removal of muscle groups and measures of flexibility of the neck in a living analogue, the ostrich (Struthio camelus. The possible effect of cartilage on flexibility is also examined, as this was previously overlooked in osteological estimates of sauropod neck function. These comparisons show that soft tissues are likely to have limited the flexibility of the neck beyond the limits suggested by osteology alone. In addition, the inferred presence of cartilage, and varying the inter-vertebral spacing within the synovial capsule, also affect neck flexibility. One hypothesis proposed that flexibility is constrained by requiring a minimum overlap between successive zygapophyses equivalent to 50% of zygapophyseal articular surface length (ONP50. This assumption is tested by comparing the maximum flexibility of the articulated cervical column in ONP50 and the flexibility of the complete neck with all tissues intact. It is found that this model does not adequately convey the pattern of flexibility in the ostrich neck, suggesting that the ONP50 model may not be useful in determining neck function if considered in isolation from myological and other soft tissue data.

Impact of pulse duration on Ho:YAG laser lithotripsy: fragmentation and dusting performance.

Science.gov (United States)

Bader, Markus J; Pongratz, Thomas; Khoder, Wael; Stief, Christian G; Herrmann, Thomas; Nagele, Udo; Sroka, Ronald

2015-04-01

In vitro investigations of Ho:YAG laser-induced stone fragmentation were performed to identify potential impacts of different pulse durations on stone fragmentation characteristics. A Ho:YAG laser system (Swiss LaserClast, EMS S.A., Nyon, Switzerland) with selectable long or short pulse mode was tested with regard to its fragmentation and laser hardware compatibility properties. The pulse duration is depending on the specific laser parameters. Fragmentation tests (hand-held, hands-free, single-pulse-induced crater) on artificial BEGO stones were performed under reproducible experimental conditions (fibre sizes: 365 and 200 µm; laser settings: 10 W through combinations of 0.5, 1, 2 J/pulse and 20, 10, 5 Hz, respectively). Differences in fragmentation rates between the two pulse duration regimes were detected with statistical significance for defined settings. Hand-held and motivated Ho:YAG laser-assisted fragmentation of BEGO stones showed no significant difference between short pulse mode and long pulse mode, neither in fragmentation rates nor in number of fragments and fragment sizes. Similarly, the results of the hands-free fragmentation tests (with and without anti-repulsion device) showed no statistical differences between long pulse and short pulse modes. The study showed that fragmentation rates for long and short pulse durations at identical power settings remain at a comparable level. Longer holmium laser pulse duration reduces stone pushback. Therefore, longer laser pulses may result in better clinical outcome of laser lithotripsy and more convenient handling during clinical use without compromising fragmentation effectiveness.

Reduced Pain and Anxiety with Music and Noise-Canceling Headphones During Shockwave Lithotripsy.

Science.gov (United States)

Karalar, Mustafa; Keles, Ibrahim; Doğantekin, Engin; Kahveci, Orhan Kemal; Sarici, Hasmet

2016-06-01

We assessed the effects of music and noise-canceling headphones (NCHs) on perceived patient pain and anxiety from extracorporeal shockwave lithotripsy (SWL). Patients with renal calculi scheduled for SWL were prospectively enrolled. All 89 patients between the ages of 19 and 80 years were informed about this study and then randomized into three groups: Group 1 (controls), no headphones and music; Group 2, music with NCHs (patients listened to Turkish classical music with NCHs during SWL); and Group 3, music with non-NCHs (patients listened to Turkish classical music with non-NCHs during SWL). Hemodynamic and respiratory parameters were recorded before and just after the SWL session. All patient visual analog scale (VAS) and State-Trait Anxiety Inventory (STAI) scores were recorded just after the SWL procedure. There were significant differences in VAS scores among the groups (5.1, 3.6, and 4.5, respectively, p < 0.001), including between Groups 2 and 3 (p = 0.018). There were also significant differences in STAI-State anxiety scores among the groups (43.1, 33.5, and 38.9, respectively, p = 0.001), including between Groups 2 and 3 (p = 0.04). Music therapy during SWL reduced pain and anxiety. Music therapy with NCHs was more effective for pain and anxiety reduction. To reduce pain and anxiety, nonpharmacologic therapies such as music therapy with NCHs during SWL should be investigated further and used routinely.

Prevalence of diabetes mellitus after extra corporeal shock wave lithotripsy in 15 years follow-up

Science.gov (United States)

Rashed, Fahimeh Kazemi; Ahmadi, Nader Rash; Zolfaghari, Ali; Farshi, Alireza; Amjadi, Mohsen; Gholipour, Mahboobeh

2017-01-01

Objective: To investigate the hypothesis that extracorporeal shock wave lithotripsy (ESWL) increases the risk of new onset diabetes mellitus (DM) or significant changes in fasting blood sugar (FBS). Materials and Methods: A total number of 307 patients enrolled in this study. All of them had undergone ESWL for kidney stone from 1991 to 1994. In 2009, after 15-19 years, we invited patients to check their blood sugar. Results: There were 307 patients, 19.8% females, and 80.1% males. The mean age of the patients was 44 for females and 42 years for males. 47.5% had kidney stone in the left side, 42.9% in the right side and 9.4% bilateral. The mean FBS increasing was 11.86 g/dl. It was 14.54 g/dl for the right side, 8.57 g/dl for left and 16.24 g/dl for bilateral ESWL. Discussions: The increasing of FBS is more significant in shock wave intensities higher than 15.5 KV. And there wasn't any significant relationship between age, sex, body mass index (BMI) and total number of shock waves with increasing of FBS. ESWL treatment might associate with increasing FBS without any relation to age, sex and BMI. PMID:28794595

Prevalence of diabetes mellitus after extra corporeal shock wave lithotripsy in 15 years follow-up

Directory of Open Access Journals (Sweden)

Fahimeh Kazemi Rashed

2017-01-01

Full Text Available Objective: To investigate the hypothesis that extracorporeal shock wave lithotripsy (ESWL increases the risk of new onset diabetes mellitus (DM or significant changes in fasting blood sugar (FBS. Materials and Methods: A total number of 307 patients enrolled in this study. All of them had undergone ESWL for kidney stone from 1991 to 1994. In 2009, after 15-19 years, we invited patients to check their blood sugar. Results: There were 307 patients, 19.8% females, and 80.1% males. The mean age of the patients was 44 for females and 42 years for males. 47.5% had kidney stone in the left side, 42.9% in the right side and 9.4% bilateral. The mean FBS increasing was 11.86 g/dl. It was 14.54 g/dl for the right side, 8.57 g/dl for left and 16.24 g/dl for bilateral ESWL. Discussions: The increasing of FBS is more significant in shock wave intensities higher than 15.5 KV. And there wasn't any significant relationship between age, sex, body mass index (BMI and total number of shock waves with increasing of FBS. ESWL treatment might associate with increasing FBS without any relation to age, sex and BMI.

Quantitative evaluation of stone fragments in extracorporeal shock wave lithotripsy using a time reversal operator

Science.gov (United States)

Wang, Jen-Chieh; Zhou, Yufeng

2017-03-01

Extracorporeal shock wave lithotripsy (ESWL) has been used widely in the noninvasive treatment of kidney calculi. The fine fragments less than 2 mm in size can be discharged by urination, which determines the success of ESWL. Although ultrasonic and fluorescent imaging are used to localize the calculi, it's challenging to monitor the stone comminution progress, especially at the late stage of ESWL when fragments spread out as a cloud. The lack of real-time and quantitative evaluation makes this procedure semi-blind, resulting in either under- or over-treatment after the legal number of pulses required by FDA. The time reversal operator (TRO) method has the ability to detect point-like scatterers, and the number of non-zero eigenvalues of TRO is equal to that of the scatterers. In this study, the validation of TRO method to identify stones was illustrated from both numerical and experimental results for one to two stones with various sizes and locations. Furthermore, the parameters affecting the performance of TRO method has also been investigated. Overall, TRO method is effective in identifying the fragments in a stone cluster in real-time. Further development of a detection system and evaluation of its performance both in vitro and in vivo during ESWL is necessary for application.

Patients' selection for treatment of caliceal diverticular stones with extracorporeal shock wave lithotripsy

Energy Technology Data Exchange (ETDEWEB)

Lee, Won Hong; Lee, Hee Jeong; Son, Soon Yong; Kang, Seong Ho; Cho, Cheong Chan; Ryu, Meung Sun [AMC, Seoul (Korea, Republic of); Kim, Seung Kook [Kwang-Ju Health College, Kwang-Ju (Korea, Republic of)

2001-06-01

Symptoms of caliceal diverticular stones are commonly associated with pain, recurrent urinary tract infection and hematuria. The aim of this study is to select the proper patient for the application of more successful extracorporeal shock wave lithotripsy(ESWL) as a treatment of caliceal diverticular stone. 16 patients with caliceal diverticular stones were treated with ESWL, and all patients had single caliceal diverticulum. The diagnosis of caliceal diverticulum with stones was made by intraveneous pyelography to all patients. On these intravenous pyelogram, we also classified diverticular type, whether the diverticular neck is connected with urinary tract patently, diverticular site and stone number and size. All patients were followed after ESWL by plain film of the kidneys, ureters and bladder and interviewed. Of all patients 44% was shown stone-free completely, also 83% was rendered symptom-free. All patients whose diverticular neck connected with urinary tract patently on the intraveneous pyelogram became stone-free. Of solitary stone 60% and multiple stones (more than 2) 17% became symptom-free. The patients with infection before ESWL 75% had residual stones, of these patients 33% had slightly flank pain, and 25% of patients with stones recurred become stone-free. We propose that more successful ESWL for patients with caliceal diverticular stones select satisfactory patients including that the diverticular neck is connected with urinary tract patently, solitary stone and no infection simultaneously.

Effects and radiation dose to patients during extracorporeal shock wave lithotripsy for kidney stones

International Nuclear Information System (INIS)

Weng Zhigen; Shao Songsheng; Shao Min

1991-01-01

Extracorporeal shock wave lithotripsy (ESWL) is rapidly becoming an accepted treatment of renal calculi. Since fluoroscopy is involved in it to image the stones, it is important to know how much radiation and effects the patients receive during ESWL. Surface radiation exposure to 134 patients and medical personnel were measured during the course of ESWL using LiF(Mg, P, Cu) thermoluminescent dosimeters. Initial results showed an average skin exposure of 162 mSv per case, with a wide range of 5 to 2360 mSv. Factors influencing exposure levels include stone characteristics (location, size and opacity), physician's experience and number of shocks required. The monthly radiation dose to personnel working in the ESWL suite averaged 0.07-0.54 mSv. The effects of radiation to patients were observed pre-and post-ESWL by using white blood cell counts, lyphocyte micronucleus assays and chromosome aberration analysis. White blood cell counts rose or reduced to > 1000 cells in 50 per cent of cases and rose in one third of cases. Lymphocyte micronuclei and chromosome aberrations were observed in 20 patients during the cources. The average frequency of micronuclei was 0.5 per mille pre-ESWL and 1 per mille post-ESWL (P < 0.05). The dicentric chromosomes were markedly increased as compared with those of pre-ESWL with statistically significant difference (P < 0.05)

Flexible Carbon Aerogels

Directory of Open Access Journals (Sweden)

Marina Schwan

2016-09-01

Full Text Available Carbon aerogels are highly porous materials with a large inner surface area. Due to their high electrical conductivity they are excellent electrode materials in supercapacitors. Their brittleness, however, imposes certain limitations in terms of applicability. In that context, novel carbon aerogels with varying degree of flexibility have been developed. These highly porous, light aerogels are characterized by a high surface area and possess pore structures in the micrometer range, allowing for a reversible deformation of the aerogel network. A high ratio of pore size to particle size was found to be crucial for high flexibility. For dynamic microstructural analysis, compression tests were performed in-situ within a scanning electron microscope allowing us to directly visualize the microstructural flexibility of an aerogel. The flexible carbon aerogels were found to withstand between 15% and 30% of uniaxial compression in a reversible fashion. These findings might stimulate further research and new application fields directed towards flexible supercapacitors and batteries.

Efficacy and safety of extracorporeal shock wave lithotripsy for chronic pancreatitis.

Science.gov (United States)

Vaysse, Thibaut; Boytchev, Isabelle; Antoni, Guillemette; Croix, Damien Sainte; Choury, André Daniel; Laurent, Valérie; Pelletier, Gilles; Buffet, Catherine; Bou-Farah, Rita; Carbonnel, Franck

2016-11-01

There is still uncertainty regarding the efficacy and optimal modalities of extracorporeal shock wave lithotripsy (ESWL) in the treatment of chronic pancreatitis. The aims of the present study were to assess the safety and the efficacy of ESWL, either alone or followed by therapeutic endoscopic retrograde cholangiopancreatography (adjuvant ERCP) and to determine predictive factors of efficacy, in a real-life setting. This study included all consecutive patients who underwent an ESWL in a single University Hospital between 2001 and 2012. The indication for ESWL was obstructive stone(s) of the main pancreatic duct resulting in either painful chronic pancreatitis or recurrent acute pancreatitis. Success was defined by resolution of pain, no analgesic treatment, no acute pancreatitis and no surgical treatment for chronic pancreatitis 6 months after the ESWL. One hundred and forty-six patients were studied; 6/146 (4%) had a complication of ESWL. Among the 132 patients in whom follow-up was completed, 91 (69%) had an adjuvant ERCP. After 6 months of follow-up, 100/132 (76%) patients achieved success. In multivariate analysis, the single significant predictive factor of the success of the ESWL treatment was chronic pain (p = 0.03). Patients who had chronic pain and needed opioid treatment had less chance of success than patients without chronic pain (OR 95%CI 0.31 [0.07-1.14]). We found no difference in the success rates between patients who underwent adjuvant ERCP and those who had ESWL only (p = 0.93). This study shows that the ESWL is a safe and effective treatment for patients with chronic pancreatitis and obstructive stones within the main pancreatic duct. Systematic association with therapeutic ERCP appears to provide no additional benefit and is therefore not recommended.

Reversibly Bistable Flexible Electronics

KAUST Repository

Alfaraj, Nasir

2015-05-01

Introducing the notion of transformational silicon electronics has paved the way for integrating various applications with silicon-based, modern, high-performance electronic circuits that are mechanically flexible and optically semitransparent. While maintaining large-scale production and prototyping rapidity, this flexible and translucent scheme demonstrates the potential to transform conventionally stiff electronic devices into thin and foldable ones without compromising long-term performance and reliability. In this work, we report on the fabrication and characterization of reversibly bistable flexible electronic switches that utilize flexible n-channel metal-oxide-semiconductor field-effect transistors. The transistors are fabricated initially on rigid (100) silicon substrates before they are peeled off. They can be used to control flexible batches of light-emitting diodes, demonstrating both the relative ease of scaling at minimum cost and maximum reliability and the feasibility of integration. The peeled-off silicon fabric is about 25 µm thick. The fabricated devices are transferred to a reversibly bistable flexible platform through which, for example, a flexible smartphone can be wrapped around a user’s wrist and can also be set back to its original mechanical position. Buckling and cyclic bending of such host platforms brings a completely new dimension to the development of flexible electronics, especially rollable displays.

Doxazosin oral intake therapy to relieve stent - related urinary symptoms and pain: a prospective, randomized, controlled study

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Long Zhang

Full Text Available ABSTRACT Objective: To assess the impact of Doxazosin Oral Intake Therapy on urinary symptoms and pain in patients with indwelling ureteral stents Patients and Methods: A total of 239 patients with ureteral stone-related hydronephrosis who underwent a double-J stent insertion after ureteroscopic lithotripsy were enrolled. Patients were randomized to receive doxazosin cotrolled release 4 mg once daily for 4 weeks or matching placebo. Patients completed the brief-form Chinese version Ureteric Stent Symptom Questionnaire (USSQ and quality of life (QoL score 2 weeks and 4 weeks after stent placement and 4 weeks after stent withdrawal. The analgesic use was also recorded during the stenting period. Results: Patients in Doxazosin Oral Intake Therapy group, in the first 2 weeks and second 2 weeks with the stent in situ, expressed significant lower daytime frequency (p=0.028 and p=0.038, nocturia (p=0.021 and p=0.008 and urgency (p=0.012 and p=0.014, respectively. Similarly, flank pain score, QoL score and analgesic use were also significant less in the stenting period. There was no significant difference in scores of urinary symptoms, pain and QoL during the post-stent period between two cohorts. Conclusions: Doxazosin Oral Intake Therapy reduced stent-related urinary symptoms, pain and the negative impact on QoL.

Tamsulosin or Silodosin Adjuvant Treatment Is Ineffective in Improving Shockwave Lithotripsy Outcome: A Short-Term Follow-Up Randomized, Placebo-Controlled Study.

Science.gov (United States)

De Nunzio, Cosimo; Brassetti, Aldo; Bellangino, Mariangela; Trucchi, Alberto; Petta, Stefano; Presicce, Fabrizio; Tubaro, Andrea

2016-07-01

The role of α-blockers after shockwave lithotripsy (SWL) is controversial. The aim of our study was to evaluate the effect of tamsulosin and silodosin after SWL for kidney stones. From 2012 onward, a consecutive series of patients undergoing SWL were prospectively enrolled and randomized by closed envelopes in three groups receiving tamsulosin 0.4 mg (A), silodosin 8 mg (B), and placebo (C) daily for 21 days after SWL. Anthropometrics, stone size, and location were recorded before SWL. Visual analogue scale (VAS) score was collected at 6, 12, and 24 hours after treatment to evaluate patients' discomfort. Stone-free rate was assessed 1 and 3 weeks postoperatively. Complications and medical treatment-related adverse events (AEs) were recorded. Differences in VAS score, stone-free rate, and complications were compared among the groups. Overall, 60 patients were enrolled. Mean stone sizes were 10.28 ± 2.46 mm, 10.45 ± 1.73 mm, and 9.23 ± 2.04 mm in groups A, B, and C, respectively (p = 0.474). There was no significant difference between the three groups with regard to stone location. Comparable energy was used to treat patients from the three groups. The overall 3-week stone-free rate was 53%: 58% in the tamsulosin group, 47% in the silodosin group, and 55% in the placebo group (p = 0.399). No significant differences were observed in the VAS scores reported by the groups at 6 hours (p = 1.254), 12 hours (p = 0.075), and 24 hours (p = 0.490). Overall, 12 complications were reported: 11 patients (7 in group C and 4 in group B) needed analgesics for colic, and 1 patient (group B) was surgically treated for Steinstrasse. Tamsulosin was superior to placebo (p = 0.008) and silodosin (p = 0.021) in preventing complications; no difference between silodosin and placebo (p = 0.629) was noted. Tamsulosin and silodosin are ineffective in increasing stone-free rate as well as early patients' discomfort after extracorporeal

Flexible MEMS: A novel technology to fabricate flexible sensors and electronics

Science.gov (United States)

Tu, Hongen

This dissertation presents the design and fabrication techniques used to fabricate flexible MEMS (Micro Electro Mechanical Systems) devices. MEMS devices and CMOS(Complementary Metal-Oxide-Semiconductor) circuits are traditionally fabricated on rigid substrates with inorganic semiconductor materials such as Silicon. However, it is highly desirable that functional elements like sensors, actuators or micro fluidic components to be fabricated on flexible substrates for a wide variety of applications. Due to the fact that flexible substrate is temperature sensitive, typically only low temperature materials, such as polymers, metals, and organic semiconductor materials, can be directly fabricated on flexible substrates. A novel technology based on XeF2(xenon difluoride) isotropic silicon etching and parylene conformal coating, which is able to monolithically incorporate high temperature materials and fluidic channels, was developed at Wayne State University. The technology was first implemented in the development of out-of-plane parylene microneedle arrays that can be individually addressed by integrated flexible micro-channels. These devices enable the delivery of chemicals with controlled temporal and spatial patterns and allow us to study neurotransmitter-based retinal prosthesis. The technology was further explored by adopting the conventional SOI-CMOS processes. High performance and high density CMOS circuits can be first fabricated on SOI wafers, and then be integrated into flexible substrates. Flexible p-channel MOSFETs (Metal-Oxide-Semiconductor Field-Effect-Transistors) were successfully integrated and tested. Integration of pressure sensors and flow sensors based on single crystal silicon has also been demonstrated. A novel smart yarn technology that enables the invisible integration of sensors and electronics into fabrics has been developed. The most significant advantage of this technology is its post-MEMS and post-CMOS compatibility. Various high

Flexible Carpooling: Exploratory Study

OpenAIRE

Dorinson, Diana; Gay, Deanna; Minett, Paul; Shaheen, Susan

2009-01-01

Energy consumption could be reduced if more people shared rides rather than driving alone yet carpooling represents a small proportion of all potential carpoolers. Prior research has found that many who might carpool were concerned about reduced flexibility with carpooling. If flexibility is one of the barriers how could carpooling be organized to be more flexible? In Northern Virginia a flexible system has evolved where there are 3,500 single-use carpools per day. In another example there ...

Local Flexibility Market Design for Aggregators Providing Multiple Flexibility Services at Distribution Network Level

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Pol Olivella-Rosell

2018-04-01

Full Text Available This paper presents a general description of local flexibility markets as a market-based management mechanism for aggregators. The high penetration of distributed energy resources introduces new flexibility services like prosumer or community self-balancing, congestion management and time-of-use optimization. This work is focused on the flexibility framework to enable multiple participants to compete for selling or buying flexibility. In this framework, the aggregator acts as a local market operator and supervises flexibility transactions of the local energy community. Local market participation is voluntary. Potential flexibility stakeholders are the distribution system operator, the balance responsible party and end-users themselves. Flexibility is sold by means of loads, generators, storage units and electric vehicles. Finally, this paper presents needed interactions between all local market stakeholders, the corresponding inputs and outputs of local market operation algorithms from participants and a case study to highlight the application of the local flexibility market in three scenarios. The local market framework could postpone grid upgrades, reduce energy costs and increase distribution grids’ hosting capacity.

Effect of Different Analgesics on Pain Relief During Extracorporeal Shock Wave Lithotripsy

Science.gov (United States)

Yesil, S; Polat, F; Ozturk, U; Dede, O; Imamoglu, MA; Bozkirli, I

2014-01-01

Background/aim: The aim of this study was  to compare  three drugs for pain relief during shock wave lithotripsy (SWL). Materials and Methods: Seventy six male patients that were treated for renal stones with SWL were included in this study. They were randomized into four groups. A different treatment protocol was used for each group.  Intramuscular (IM) diclofenac 75mg was given in group 1 (n=20), dexketoprofen, 50mg, IM in group 2 (n=20) and hyoscine 10 mg plus paracetamol 500mg, orally in group 3 (n=20). In group 4 (control, n=16) saline solution   was given 30 min before SWL. Pain during SWL was assessed using the 10-score linear visual analogue pain scale (VAS) and was compared among groups. Age, weight, height, body mass index (BMI), stone size, stone location, duration of SWL, total shock waves performed and mean energy level (kV) for each patient were recorded. A p value of <0.05 was considered statistically significant. Results: The mean patients’ age was 45.4 ± 12.9 years. The highest VAS value was observed in Group 4 (8.4 ± 1), and the lowest  in Group 1 (6.25 ± 2.2).  Statistically significant  difference was noted  only when Group 1 and Group 4 were compared. The remaining groups provided similar results and there were no significant statistical differences according to VAS values. Other parameters were similar  in all groups. Conclusion: In conclusion, this study shows that reducing the pain with a single dose injection of intramuscular diclofenac sodium before SWL is superior compared to others. PMID:25336870

[Inspecting the cochlear scala tympanic with flexible and semi-flexible micro-endoscope].

Science.gov (United States)

Zhang, Daoxcing; Zhang, Yankun

2006-02-01

Flexible and semi-flexible micro-endoscopes were used in cochlear scala tympani inspection , to explore their application in inner ear examination. Fifteen profound hearing loss patients preparing for cochlear implant were included in this study. During the operation, micro-endoscopy was performed after opening the cochlear scala tympani. And 1 mm diameter semi-flexible micro-endoscope could go as deep as 9 mm into the cochlear scala tympani, while 0. 5 mm diameter flexible micro-endoscope could go as deep as 25 mm. The inspecting results were compared with video recording. Using 0.5 mm flexible micro-endoscope, we canould check cochlear scala tympani with depth range of 15-25 mm, but the video imaging was not clear enough to examine the microstructure in the cochlear. With 1 mm diameter semi-flexible micro-endoscope, we could reach 9 mm deep into the cochlear. During the examination, we found 3 cases with calcification deposit in osseous spiral lamina, l case with granulation tissue in the lateral wall of scala tympani, no abnormal findings in the other 11 cases. Inspecting the cochlear scala tympani with 0.5 mm flexible micro-endoscope, even though we can reach the second circuit of the cochlear, it is difficult to find the pathology in the cochlear because of the poor video imaging. With 1 mm semi-flexible micro-endoscope, we can identify the microstructure of the cochlear clearly and find the pathologic changes, but the inserting depth was limited to 9 mm with limitation to examine the whole cochlear.

Development of Flexible Pneumatic Cylinder with Built-in Flexible Linear Encoder and Flexible Bending Sensor

Science.gov (United States)

Akagi, Tetsuya; Dohta, Shujiro; Matsushita, Hisashi; Fukuhara, Akimasa

The purpose of this study is to develop a lightweight and intelligent soft actuator which can be safely attached to the human body. A novel flexible pneumatic cylinder that can be used even if it is deformed by external force had been proposed. The cylinder can realize both pushing and pulling motions even if the cylinder bends. In this paper, a flexible pneumatic cylinder with a built-in flexible linear encoder is proposed and tested. The encoder can detect the cylinder displacement even if the cylinder bends. In the next step, to realize an intelligent flexible cylinder, it is essential to recognize the angle of deflection of the cylinder to estimate the direction of the external force. Therefore, a flexible bending sensor that can measure the directional angle by attaching it to the end of the cylinder is also proposed and tested. The tested bending sensor also consists of four inexpensive photo-reflectors set on the circumferential surface to the cylinder tube every 90 degrees from the center of the tube. By measuring the distance between the photo reflector and the surface of the tube at each point, the bending directional angle of the cylinder can be obtained. A low cost measuring system using a micro-computer incorporating a programmed Up/Down counter to measure the displacement of the cylinder is also developed. As a result, it was confirmed that the measuring accuracy of the bending directional angle was good, less than 0.7 degrees as a standard deviation.

Development of a urinary lithiasis localizer mechanism to couple ultrasound and extracorporeal lithotripsy equipment in canine model

Directory of Open Access Journals (Sweden)

Enrico Andrade

2006-10-01

Full Text Available INTRODUCTION: Due to the evolution of extracorporeal lithotripsy equipment (ESWL and presently, the fact that most part of the equipment does not present ultrasound to localize urinary calculi, a system that allows adapting ultrasound equipment to ESWL equipment was developed, disposing only of fluoroscopy. Thus, this equipment was developed and was tested in urinary stones in canine models, to check its precision in relation to fluoroscopy. METHOD: Seven male dogs were utilized with the introduction, in the bladder through the ureteral route, of chalkstones, with initial localization by fluoroscopy, with a further ultrasound coincidence check localization of the vesical stones, being submitted to ESWL with a 3-hour, 21 days and 60 days follow-up after the procedure. RESULTS: Success of localization in all animals was verified presenting elimination of stones in the first micturitions, after ESWL. No complications were verified in those animals for 60 days. CONCLUSION: We verified that this equipment can lead to an update of the equipment that use only fluoroscopy, increasing in this way, their technical capacity in the treatment of urinary calculi, mainly in cases of non-radiopaque stones.

Energy Flexibility in Retail Buildings

DEFF Research Database (Denmark)

Ma, Zheng; Billanes, Joy Dalmacio; Kjærgaard, Mikkel Baun

2017-01-01

Retail buildings has an important role for demand side energy flexibility because of their high energy consumption, variety of energy flexibility resources, and centralized control via building control systems. Energy flexibility requires agreements and collaborations among different actors......), with the discussion of the stakeholders’ roles and their interrelation in delivering energy flexibility with the influential factors to the actual implementation of energy flexible operation of their buildings. Based on a literature analysis, the results cover stakeholders’ types and roles, perceptions (drivers......, barriers, and benefits), energy management activities and technology adoptions, and the stakeholders’ interaction for the energy flexibility in retail buildings....

Flexible Word Classes

DEFF Research Database (Denmark)

• First major publication on the phenomenon • Offers cross-linguistic, descriptive, and diverse theoretical approaches • Includes analysis of data from different language families and from lesser studied languages This book is the first major cross-linguistic study of 'flexible words', i.e. words...... that cannot be classified in terms of the traditional lexical categories Verb, Noun, Adjective or Adverb. Flexible words can - without special morphosyntactic marking - serve in functions for which other languages must employ members of two or more of the four traditional, 'specialised' word classes. Thus......, flexible words are underspecified for communicative functions like 'predicating' (verbal function), 'referring' (nominal function) or 'modifying' (a function typically associated with adjectives and e.g. manner adverbs). Even though linguists have been aware of flexible world classes for more than...

Flexible magnetoimpedance sensor

KAUST Repository

Li, Bodong; Kavaldzhiev, Mincho; Kosel, Jü rgen

2015-01-01

Flexible magnetoimpedance (MI) sensors fabricated using a NiFe/Cu/NiFe tri-layer on Kapton substrate have been studied. A customized flexible microstrip transmission line was employed to investigate the MI sensors's magnetic field and frequency

Flexible magnetoimpedance sensor

International Nuclear Information System (INIS)

Li, Bodong; Kavaldzhiev, Mincho N.; Kosel, Jürgen

2015-01-01

Flexible magnetoimpedance (MI) sensors fabricated using a NiFe/Cu/NiFe tri-layer on Kapton substrate have been studied. A customized flexible microstrip transmission line was employed to investigate the MI sensors's magnetic field and frequency responses and their dependence on the sensors's deflection. For the first time, the impedance characteristic is obtained through reflection coefficient analysis over a wide range of frequencies from 0.1 MHz to 3 GHz and for deflections ranging from zero curvature to a radius of 7.2 cm. The sensor element maintains a high MI ratio of up to 90% and magnetic sensitivity of up to 9.2%/Oe over different bending curvatures. The relationship between the curvature and material composition is discussed based on the magnetostriction effect and stress simulations. The sensor's large frequency range, simple fabrication process and high sensitivity provide a great potential for flexible electronics and wireless applications. - Highlights: • A flexible magnetoimpedance (MI) sensor is developed. • Studies are carried out using a flexible microstrip transmission line. • An MI ratio of up to 90% is obtained. • The effect of magnetostriction is studied

Flexible transparent electrode

Science.gov (United States)

Demiryont, Hulya; Shannon, Kenneth C., III; Moorehead, David; Bratcher, Matthew

2011-06-01

This paper presents the properties of the EclipseTECTM transparent conductor. EclipseTECTM is a room temperature deposited nanostructured thin film coating system comprised of metal-oxide semiconductor elements. The system possesses metal-like conductivity and glass-like transparency in the visible region. These highly conductive TEC films exhibit high shielding efficiency (35dB at 1 to 100GHz). EclipseTECTM can be deposited on rigid or flexible substrates. For example, EclipseTECTM deposited on polyethylene terephthalate (PET) is extremely flexible that can be rolled around a 9mm diameter cylinder with little or no reduction in electrical conductivity and that can assume pre-extension states after an applied stress is relieved. The TEC is colorless and has been tailored to have high visible transmittance which matches the eye sensitivity curve and allows the viewing of true background colors through the coating. EclipseTECTM is flexible, durable and can be tailored at the interface for applications such as electron- or hole-injecting OLED electrodes as well as electrodes in flexible displays. Tunable work function and optical design flexibility also make EclipseTECTM well-suited as a candidate for grid electrode replacement in next-generation photovoltaic cells.

Flexible Foam Model.

Energy Technology Data Exchange (ETDEWEB)

Neilsen, Michael K.; Lu, Wei-Yang; Werner, Brian T.; Scherzinger, William M.; Lo, Chi S.

2018-03-01

Experiments were performed to characterize the mechanical response of a 15 pcf flexible polyurethane foam to large deformation at different strain rates and temperatures. Results from these experiments indicated that at room temperature, flexible polyurethane foams exhibit significant nonlinear elastic deformation and nearly return to their original undeformed shape when unloaded. However, when these foams are cooled to temperatures below their glass transition temperature of approximately -35 o C, they behave like rigid polyurethane foams and exhibit significant permanent deformation when compressed. Thus, a new model which captures this dramatic change in behavior with temperature was developed and implemented into SIERRA with the name Flex_Foam to describe the mechanical response of both flexible and rigid foams to large deformation at a variety of temperatures and strain rates. This report includes a description of recent experiments. Next, development of the Flex Foam model for flexible polyurethane and other flexible foams is described. Selection of material parameters are discussed and finite element simulations with the new Flex Foam model are compared with experimental results to show behavior that can be captured with this new model.

Comparison of Pneumatic and Laser Lithotripsy in the Endoscopic Treatment of Upper Ureteral Stones

Directory of Open Access Journals (Sweden)

Ozer Guzel

2016-04-01

Full Text Available Aim: We aimed to compare the success rate of the use of a pneumatic and a holmium laser lithotripter for endoscopic treatment of upper ureteral calculi with semirigid uretero-renoscopy (URS. Material and Method: A total of 74 patients were included in this study. The patients were divided into two groups; a ballistic lithotripter was used for group 1 containing 33 and a Holmium-YAG laser lithotripter for the remaining 41 patients in group 2. Both groups were compared in terms of stone size the duration of the operation, postoperative hospitalization time, stone-free rate and complications. Results: The mean age of the patients was 47.6. The mean stone size in groups 1 and 2 were 16.4mm and 11.0mm, respectively (p=0.043. The mean stone-free rate groups 1 and 2 were 78.7% and 80.5% respectively at the approximately 1 month follow-up (p=0.391. In group 1 two patients and in group 2 two patients had a minor complication (ClavienI-II. In group 1 three patients had major complications due to ureteral perforation (Clavien 3a and 3b. No major complications (Clavien III-V occurred in Group 2. Discussion: Based on these findings laser lithotripsy can be regarded as safer. If laser lithotripter is available in medical centers, we argue that it should be the first choice for the treatment of upper ureteral stones.

[Extracorporeal shockwave lithotripsy (ESWL) for salivary gland stones: a retrospective study of 1571 patients].

Science.gov (United States)

Guerre, A; Katz, P

2011-04-01

The fragmentation of salivary stones by extracorporeal shockwave lithotripsy (ESWL) has been described since the 1990s. We wanted to assess its effectiveness through a retrospective study. We reviewed the files of 1571 patients (801 women and 770 men, from 6 to 85 years of age) treated by ESWL between 1995 and 2010 for 1031 submandibular (65.6%) and 540 parotid gland sialolithiasis (34.4%). The treatment consisted in one or several sessions of ESWL distributed over 3 to 24 months. Three thousand to 6000 shockwaves were delivered by session, if there was no hemostatic disorder or infection. Ultrasound control examinations were performed regularly and systematically. An average of six sessions was necessary. All the lithiases were fragmented, 1056 (67.2%) totally and 515 (32.8%) partially with residual fragments from 1 to 6mm in size. After treatment, 1446 patients (92%) were asymptomatic and 125 (8%) continued to present salivary symptoms, without residual fragments on ultrasound examination in 82% of the cases. The main adverse reaction was infection (628 patients, 40%) resolved thanks to antibiotic treatment or extraction of fragments under local anesthesia. Developed for 20 years, LEC is an excellent alternative to conventional surgery as long as indications are respected. It seems very effective, but its drawbacks are the length of management and the difficulty of ultrasound localization of calculi, which requires an experienced operator. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

Evaluation of the dose to patients during extracorporated lithotripsy treatment (ESWL); Evaluacion de dosis a paciente durante el tratamiento con litotricia extracorporea (ESWL)

Energy Technology Data Exchange (ETDEWEB)

Rodriguez, M F; Roman, J R [Servicio de Fisica Medica, Hospital Universitario de Valme, Sevilla (Spain)

1997-11-01

Litiasis urinaria is appearing more frequently with approximately 12% of the population with a stone in the urinary system at any moment of their life. The stone produces severe colics causing pain in the transit through the ureter. This is probably one of the worst pains and experiences in human beings. The treatment by extracorporated lithotripsy consists of powdering or smashing into pieces the stones in the kidney and ureter. This has been done with the help of shock waves generated from a canon and which are focused on the stone. The machine used is aimed and the procedure is monitored by way of X rays. The high number of patients treated per year and the doses applied to the patients during the diagnosis, treatment and follow-up led to this study. 7 refs, 5 figs, 4 tabs.

Performance and safety of holmium: YAG laser optical fibers.

Science.gov (United States)

Knudsen, Bodo E; Glickman, Randolph D; Stallman, Kenneth J; Maswadi, Saher; Chew, Ben H; Beiko, Darren T; Denstedt, John D; Teichman, Joel M H

2005-11-01

Lower-pole ureteronephroscopy requires transmission of holmium:YAG energy along a deflected fiber. Current ureteroscopes are capable of high degrees of deflection, which may stress laser fibers beyond safe limits during lower-pole use. We hypothesized that optical fiber and safety measures differ among manufacturers. Small (200-273-microm) and medium-diameter (300-400-microm) Ho:YAG fibers were tested in a straight and 180 degrees bent configuration. Energy transmission was measured by an energy detector. Fiber durability was assessed by firing the laser in sequentially tighter bending diameters. The fibers were bent to 180 degrees with a diameter of 6 cm and run at 200- to 4000-mJ pulse energy to determine the minimum energy required to fracture the fiber. The bending diameter was decreased by 1-cm increments and testing repeated until a bending diameter of 1 cm was reached. The maximum deflection of the ACMI DUR-8E ureteroscope with each fiber in the working channel was recorded. The flow rate through the working channel of the DUR-8E was measured for each fiber. The mean energy transmission differed among fibers (P < 0.001). The Lumenis SL 200 and the InnovaQuartz 400 were the best small and medium-diameter fibers, respectively, in resisting thermal breakdown (P < 0.01). The Dornier Lightguide Super 200 fractured repeatedly at a bend diameter of 2 cm and with the lowest energy (200 mJ). The other small fibers fractured only at a bend diameter of 1 cm. The Sharplan 200 and InnovaQuartz Sureflex 273T were the most flexible fibers, the Lumenis SL 365 the least. The flow rate was inversely proportional to four times the power of the diameter of the fiber. Optical performance and safety differ among fibers. Fibers transmit various amounts of energy to their cladding when bent. During lower-pole nephroscopy with the fiber deflected, there is a risk of fiber fracture from thermal breakdown and laser-energy transmission to the endoscope. Some available laser fibers

Incentivizing Flexibility in System Operations

Energy Technology Data Exchange (ETDEWEB)

Milligan, Michael [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Bloom, Aaron P [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Townsend, Aaron [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Ela, Erik [Electric Power Research Institute; Botterud, Audun [Argonne National Laboratory; Levin, Todd [Argonne National Laboratory

2018-02-15

Defining flexibility has been a challenge that a number of industry members and researchers have attempted to address in recent years. With increased variability and uncertainty of variable generation (VG), the resources on the system will have to be more flexible to adjust output, so that power output ranges, power ramp rates, and energy duration sustainability are sufficient to meet the needs of balancing supply with demand at various operational timescales. This chapter discusses whether existing market designs provide adequate incentives for resources to offer their flexibility into the market to meet the increased levels of variability and uncertainty introduced by VG in the short-term operational time frame. It presents a definition of flexibility and discusses how increased levels of VG require increased needs for flexibility on power systems. Following this introductory material, the chapter examines how existing market designs ensure that resources have the right incentives to provide increased flexibility, and then discusses a number of emerging market design elements that impact flexibility incentives.

Graphene-based materials for flexible supercapacitors.

Science.gov (United States)

Shao, Yuanlong; El-Kady, Maher F; Wang, Lisa J; Zhang, Qinghong; Li, Yaogang; Wang, Hongzhi; Mousavi, Mir F; Kaner, Richard B

2015-06-07

The demand for flexible/wearable electronic devices that have aesthetic appeal and multi-functionality has stimulated the rapid development of flexible supercapacitors with enhanced electrochemical performance and mechanical flexibility. After a brief introduction to flexible supercapacitors, we summarize current progress made with graphene-based electrodes. Two recently proposed prototypes for flexible supercapacitors, known as micro-supercapacitors and fiber-type supercapacitors, are then discussed. We also present our perspective on the development of graphene-based electrodes for flexible supercapacitors.

Flexible Metal Oxide/Graphene Oxide Hybrid Neuromorphic Devices on Flexible Conducting Graphene Substrates

OpenAIRE

Wan, Chang Jin; Wang, Wei; Zhu, Li Qiang; Liu, Yang Hui; Feng, Ping; Liu, Zhao Ping; Shi, Yi; Wan, Qing

2016-01-01

Flexible metal oxide/graphene oxide hybrid multi-gate neuron transistors were fabricated on flexible graphene substrates. Dendritic integrations in both spatial and temporal modes were successfully emulated, and spatiotemporal correlated logics were obtained. A proof-of-principle visual system model for emulating lobula giant motion detector neuron was investigated. Our results are of great interest for flexible neuromorphic cognitive systems.

Clinical experience with EDAP LT-01+ extracorporeal shock wave lithotripsy for radiolucent stones; a report of 27 cases

International Nuclear Information System (INIS)

Rim, Hee Kwan; Kim, Ho Sung; Rim, Joung Sik

1994-01-01

Between February 1990 and February 1993, Radiolucent stones of 27 renal units in 22 patients were treated by extracorporeal shock wave lithotripsy (ESWL) using the EDAP LT-01+. Intravenous urography was done in all patients for the diagnosis of radiolucent stones. Retrograde pyelography, ultrasonography and/or computed tomography was done, if needed. The locations of stones were kidney in 11(40.7 %), upper ureter in 8(29.6 %), lower ureter in 6(22.2 %), bladder in 1(3.7 %), ureteropelvic junction in 1(3.7 %). The average stone size was 10.9mm with a range of 5 to 32mm in maximum diameter. The average numbers of treatment were 2.7 sessions and average storage required was 34.8 in one session. The average treatment time was 40.4 minutes. All the patients showed complete removal of all calculous materials. Of 17 urinary stones analysed by chemical method, 8(47.1 %) were composed of uric acid, 5(29.4 %) of uric acid and calcium, 3 of phosphate and 1 of carbonate and phosphate. Therefore, we conclude that ESWL with EDAP LT-01+ lithotriptor is considered to be an effective noninvasive procedure for treatment of radiolucent stones. (Author)

Flexible Electronics Research Facility

Data.gov (United States)

Federal Laboratory Consortium — The Flexible Electronics Research Facility designs, synthesizes, tests, and fabricates materials and devices compatible with flexible substrates for Army information...

Flexibility within Fidelity

Science.gov (United States)

Kendall, Philip C.; Gosch, Elizabeth; Furr, Jami M.; Sood, Erica

2008-01-01

The authors address concerns regarding manual-based treatments, highlighting the role of flexibility and creativity. A cognitive-behavioral therapy for youth anxiety called the Coping Cat program demonstrates the flexible application of manuals and emphasizes the importance of a child-centered, personalized approach that involves the child in the…

An intrahepatic calculus superimposed over the right renal shadow: a case of mistaken identity.

Science.gov (United States)

Learney, Robert M; Shrotri, Nitin

2010-08-01

A 36-year-old Caucasian British woman presented with a classic case of right renal colic. Initial plain abdominal radiography and intravenous urography identified an 8 x 5 mm calculus apparently lying within a right lower pole calyx. Following failed extracorporeal lithotripsy and flexible ureterorenoscopy, cross-sectional imaging revealed a misdiagnosis by superposition of an intrahepatic calculus over the right renal shadow. This case serves to support cross-sectional imaging in the diagnosis of renal calculi. Copyright 2010 Elsevier Inc. All rights reserved.

WAGE FLEXIBILITY IN THE CONTEMPORARY SOCIETY

Directory of Open Access Journals (Sweden)

TECULESCU Silviu Alexandru

2010-12-01

Full Text Available The paper follows to offer the most efficient solutions for the attainment by Romania of the economic development level associated to the Western European countries. It proposes the division of the flexibility of labour market in three components, namely: internal flexibility, external flexibility and wage flexibility. The analysis performed within the present study will emphasize the wage flexibility. Wage flexibility can be classified in four components: a plans of individual and group incentives; b plans of assigning wages out of productivity; c plans of distribution of profits and, respectively, d plans of suggestions. The labour market flexibility, in general, and especially the wage flexibility contributes to the increase of employee motivation at the workplace, aspect which leeds to the growth of labour productivity, through this one being put the bases of the medium- and long-term economic development.

Energy Flexibility in the Power System

DEFF Research Database (Denmark)

Billanes, Joy Dalmacio; Ma, Zheng; Jørgensen, Bo Nørregaard

2017-01-01

Energy flexibility can address the challenges of large scale integration of renewable energy resources and thereby increasing imbalance in the power system. Flexible power system can provide reliable supply, low electricity cost and sustainability. Various situations and factors influence...... the adoption of the flexibility solutions, such as flexible electricity generation, demand-response, and electricity storage. This paper tries to analyze the current energy flexibility solutions and the factors that can influence the energy flexibility adoption. This paper takes Philippines as case study...... to provide an overview of the current condition of the Philippines’ power system and discuss the energy flexibility in the Philippines’ power system. A further discussion and recommendation is conducted in the end of the paper....

Diagnostic and prognostic role of computed tomography in extracorporeal shock wave lithotripsy complications.

Science.gov (United States)

Telegrafo, Michele; Carluccio, Davide Antonio; Rella, Leonarda; Ianora, Amato Antonio Stabile; Angelelli, Giuseppe; Moschetta, Marco

2016-01-01

To evaluate the role of multidetector computed tomography (MDCT) in recognizing the complications of extracorporeal shock wave lithotripsy (ESWL) and providing a prognostic grading system for the therapeutic approach. A total of 43 patients who underwent ESWL because of urinary stone disease were assessed by 320-row MDCT examination before and after ESWL. Pre-ESWL CT unenhanced scans were performed for diagnosing stone disease. Post-ESWL CT scans were acquired before and after intravenous injection of contrast medium searching for peri-renal fluid collection or hyper-density, pyelic or ureteral wall thickening, blood clots in the urinary tract, peri- or intra-renal hematoma or abscess, active bleeding. A severity grading system of ESWL complications was established. Patients were affected by renal (n = 36) or ureteral (n = 7) lithiasis. Post-ESWL CT examination detected small fluid collections and hyper-density of peri-renal fat tissue in 35/43 patients (81%), pyelic or ureteral wall thickening in 2/43 (4%), blood clots in the urinary tract in 9/43 (21%), renal abscesses or hematomas with a diameter of <2 cm in 10/43 (23%), large retroperitoneal collections in 3/43 (7%), active bleeding from renal vessels in 1/43 (2%). Mild complications were found in 30 cases; moderate in 9; severe in 4. The therapeutic choice was represented by clinical follow-up (n = 20), clinical and CT follow-up (n = 10), ureteral stenting (n = 9), drainage of large retroperitoneal collections (n = 3), and arterial embolization (n = 1). MDCT plays a crucial role in the diagnosis of urolithiasis and follow-up of patients treated with ESWL recognizing its complications and providing therapeutic and prognostic indications.

Extracorporeal shockwave lithotripsy versus ureteroscopy for distal ureteric calculi: efficacy and patient satisfaction

Directory of Open Access Journals (Sweden)

Ibrahim F. Ghalayini

2006-12-01

Full Text Available OBJECTIVE: We compared the efficacy of extracorporeal shock wave lithotripsy (ESWL and ureteroscopy (URS for the treatment of distal ureteral calculi with respect to patient satisfaction. MATERIALS AND MHETODS: This is a prospective study where a total of 212 patients with solitary, radiopaque distal ureteral calculi were treated with ESWL (n = 92 using Dornier lithotriptor S (MedTech Europe GmbH or URS (n = 120. Patient and stone characteristics, treatment parameters, clinical outcomes, and patient satisfaction were assessed for each group. RESULTS: The 2 groups were comparable in regard to patient age, sex, stone size, and side of treatment. The stone-free status for ESWL and URS at 3 months was 81.5% and 97.5%, respectively (p < 0.0001. In addition, 88% of patients who underwent ESWL versus 20% who underwent URS were discharged home the day of procedure. Minor complications occurred in 3.3% and 8.3% of the ESWL and URS groups, respectively (p = 0.127. No ureteral perforation or stricture occurred in the URS group. Postoperative flank pain and dysuria were more severe in the URS than ESWL group, although the differences were not statistically significant (p = 0.16. Patient satisfaction was high for both groups, including 94% for URS and 80% for ESWL (p = 0.002. CONCLUSIONS: URS is more effective than ESWL for the treatment of distal ureteral calculi. ESWL was more often performed on an outpatient basis, and showed a trend towards less flank pain and dysuria, fewer complications and quicker convalescence. Patient satisfaction was significantly higher for URS according to the questionnaire used in this study.

Predictive factors of lower calyceal stone clearance after extracorporeal shockwave lithotripsy (ESWL): the impact of radiological anatomy.

Science.gov (United States)

Lin, Chih-Chieh; Hsu, Yen-Shen; Chen, Kuang-Kuo

2008-10-01

This study was carried out to determine whether or not there is a significant relationship between the radiologic anatomy of the lower calyx, as seen on preoperative intravenous urography (IVU), and the outcome of stone clearance after extracorporeal shockwave lithotripsy (ESWL) for lower renal calyceal stones. Between June 1998 and April 2007, 112 patients with a solitary lower renal calyceal stone measuring 20 mm or less in size were enrolled in this retrospective study. Pretreatment IVU was reviewed for measuring the anatomical predictors, such as lower pole infundibular length, infundibular width (IW) and infundibulopelvic angle, while the stone location and size were determined on plain abdominal X-ray. All patients were treated with ESWL using a Siemens Lithostar Plus lithotriptor and were followed-up for the outcome of stone clearance 3 months after ESWL with plain abdominal X-ray films and ultrasonography. Three months after ESWL, only 49 (43.7%) patients were stone-free. Under multivariate analysis with logistic regression, smaller stone size (10 mm or less, p = 0.005) and greater IW (4 mm or more, p = 0.029) were significant favourable predictors for better stone clearance. In addition to the influence of stone size, lower pole anatomy, especially IW, has a significant impact on stone clearance for lower calyceal stone after ESWL.

Organizational flexibility estimation

OpenAIRE

Komarynets, Sofia

2013-01-01

By the help of parametric estimation the evaluation scale of organizational flexibility and its parameters was formed. Definite degrees of organizational flexibility and its parameters for the Lviv region enterprises were determined. Grouping of the enterprises under the existing scale was carried out. Special recommendations to correct the enterprises behaviour were given.

Inter-Vertebral Flexibility of the Ostrich Neck: Implications for Estimating Sauropod Neck Flexibility

OpenAIRE

Cobley, Matthew J.; Rayfield, Emily J.; Barrett, Paul M.

2013-01-01

The flexibility and posture of the neck in sauropod dinosaurs has long been contentious. Improved constraints on sauropod neck function will have major implications for what we know of their foraging strategies, ecology and overall biology. Several hypotheses have been proposed, based primarily on osteological data, suggesting different degrees of neck flexibility. This study attempts to assess the effects of reconstructed soft tissues on sauropod neck flexibility through systematic removal o...

Plain radiography, renography, and [sup 99m]Tc-DMSA renal scintigraphy before and after extracorporeal shock wave lithotripsy for urolithiasis

Energy Technology Data Exchange (ETDEWEB)

Munck, O.; Gerquari, I.; Moeller, J.T.; Jensen, L.I.; Thomsen, H.S. (Dept. of Clinical Physiology, Dept. of Nuclear Medicine, Dept. of Diagnostic Radiology, Herlev Hospital, Copenhagen Univ. (Denmark))

1992-11-01

Eighteen patients were evaluated before and 5 weeks after the first treatment with extracorporeal shock wave lithotripsy (ESWL) using abdominal plain radiography, [sup 131]I-hippuran probe renography, and [sup 99m]Tc-dimercaptosuccinic acid scintigraphy. In 6 patients no urolithiasis was present on the post ESWL plain radiograph, in 7 the size had decreased, and in 5 the stone mass was unchanged. The renograms were within normal range in the 6 patients who were cured by ESWL, whereas this was the case for only 4 of the 12 who still had renal calculi. In 2 patients pelvic stones had descended into the ureter after ESWL, and the renograms indicated obstruction. Another 3 patients had ureteral stones, whereas in the remaining 7 patients only pelvic stones were found on the plain radiographs. In no patient did the scintigrams reveal scars. It is concluded that abdominal plain radiography of the urinary tract and probe renography are complementary and sufficient in the monitoring of patients with urolithiasis post ESWL. (orig.).

Flexible automated manufacturing for SMEs

DEFF Research Database (Denmark)

Grube Hansen, David; Bilberg, Arne; Madsen, Erik Skov

2017-01-01

SMEs are in general highly flexible and agile in order to accommodate the customer demands in the paradigm of High Mix-Low Volume manufacturing. The flexibility and agility have mainly been enabled by manual labor, but as we are entering the technology and data driven fourth industrial revolution......, where augmented operators and machines work in cooperation in a highly flexible and productive manufacturing system both an opportunity and a need has raised for developing highly flexible and efficient automation....

On flexible and rigid nouns

DEFF Research Database (Denmark)

Rijkhoff, Jan

2010-01-01

classes. Finally this article wants to claim that the distinction between rigid and flexible noun categories (a) adds a new dimension to current classifications of parts of speech systems, (b) correlates with certain grammatical phenomena (e.g. so-called number discord), and (c) helps to explain the parts......This article argues that in addition to the major flexible lexical categories in Hengeveld’s classification of parts of speech systems (Contentive, Non-Verb, Modifier), there are also flexible word classes within the rigid lexical category Noun (Set Noun, Sort Noun, General Noun). Members...... by the flexible item in the external world. I will then argue that flexible word classes constitute a proper category (i.e. they are not the result of a merger of some rigid word classes) in that members of flexible word categories display the same properties regarding category membership as members of rigid word...

On flexible and rigid nouns

DEFF Research Database (Denmark)

Rijkhoff, Jan

2008-01-01

Studies in Language 32-3 (2008), 727-752. Special issue: Parts of Speech: Descriptive tools, theoretical constructs Jan Rijkhoff - On flexible and rigid nouns This article argues that in addition to the flexible lexical categories in Hengeveld’s classification of parts-of-speech systems (Contentive......, Non-Verb, Modifier), there are also flexible word classes within the rigid lexical category Noun (Set Noun, Sort Noun, General Noun). Members of flexible word classes are characterized by their vague semantics, which in the case of nouns means that values for the semantic features Shape...... and Homogeneity are either left undetermined or they are specified in such a way that they do not quite match the properties of the kind of entity denoted by the flexible item in the external world. I will then argue that flexible word classes constitute a proper category (i.e. they are not the result of a merger...

Flexible magnetoimpidence sensor

KAUST Repository

Kavaldzhiev, Mincho

2015-05-01

Recently, flexible electronic devices have attracted increasing interest, due to the opportunities they promise for new applications such as wearable devices, where the components are required to flex during normal use[1]. In this light, different magnetic sensors, like microcoil, spin valve, giant magnetoresistance (GMR), magnetoimpedance (MI), have been studied previously on flexible substrates.

Global Analysis of Flexible Risers

DEFF Research Database (Denmark)

Banke, Lars

1996-01-01

Flexible pipes are often a technically attractive alternative to the traditional steel pipe. Often commercial utilisation of oil/gas fields depends on the use of flexible pipes. An example is when floating production vessels are used, where the flexible pipe follows the wave induced motions...

Designing structural supply chain flexibility

NARCIS (Netherlands)

Mulinski, Ksawery Jan

2012-01-01

In a continuously changing business environment the role of supply chain flexibility is constantly increasing. A flexible supply chain can ensure survival in quickly changing market conditions as well as enable sustainable growth. This thesis explores the topic of supply chain flexibility with focus

Flexibility in insulin prescription

Directory of Open Access Journals (Sweden)

Sanjay Kalra

2016-01-01

Full Text Available This communication explores the concept of flexibility, a propos insulin preparations and insulin regimes used in the management of type 2 diabetes. The flexibility of an insulin regime or preparation is defined as their ability to be injected at variable times, with variable injection-meal time gaps, in a dose frequency and quantum determined by shared decision making, with a minimal requirement of glucose monitoring and health professional consultation, with no compromise on safety, efficiency and tolerability. The relative flexibility of various basal, prandial and dual action insulins, as well as intensive regimes, is compared. The biopsychosocial model of health is used to assess the utility of different insulins while encouraging a philosophy of flexible insulin usage.

Treatment of Kidney Stones Using Extracorporeal Shock Wave Lithotripsy (ESWL) and Double-J Stent in Infants.

Science.gov (United States)

Younesi Rostami, Mehdi; Taghipour-Gorgikolai, Mehrdad; Sharifian, Rayka

2012-01-01

Background. Extracorporeal shock wave lithotripsy (ESWL) has progressively acquired popularity as being the gold standard treatment for upper urinary tract lithiasis in infants since 1980. Our aim was to evaluate the outcome of ESWL for kidney stones and the use of double-J stent in infants. Material and Methods. A prospective clinical trial study performed on 50 infants with renal calculi at pelvic admitted in the Urology ward of Shafa Hospital, Sari, Iran, between 2001 and 2010. Main outcome measure of our study was clearing stones after one or more consecutive sessions of ESWL. Results. The study included 50 patients with renal calculi at pelvic. Among them, there were 35 (70%) boys and 15 (30%) girls with the age ranging from 1 to 13 months (mean of 7 month ± 3 days). All of them were treated by standard ESWL using Simons Lithostor plus machine. The stone sizes ranged from 6 mm to 22 mm. Double-J stents were placed in 11 infants (22%) with stones larger than 13 mm. Most of the patients required only one ESWL session. Conclusion. Since there were no complications following ESWL treatment, we can conclude that, in short term, ESWL is an effective and safe treatment modality for renal lithiasis in infants. In addition, we recommend double-J stent in infants with stones larger than 13 mm.

Studies of renal parenchymal impairments with extracorporeal shock wave lithotripsy (ESWL) by diagnostic imaging methods

Energy Technology Data Exchange (ETDEWEB)

Ohishi, Yukihiko; Machida, Toyohei; Tashiro, Kazuya; Wada, Tetsuro; Mochizuki, Atsushi; Torii, Shinichiro; Yoshigoe, Fukuo; Kawashima, Yoshio; Asano, Koji (Jikei Univ., Tokyo (Japan). School of Medicine)

1989-05-01

Renal parenchymal impairments with extracorporeal shock wave lithotripsy (ESWL) were studied by diagnostic imaging methods. The subjects were 25 patients with renal stones, and EDAP LT-01 (piezoelectric system) was used for the equipment of ESWL. The examination by MRI, X-ray CT and /sup 99m/Tc-DMSA scintigraphy using SPECT were performed before and after ESWL. To the 24 kidneys of 12 adult dogs, shock waves were fired in order to examine the experimental renal parenchymal impairments. After the treatment with ESWL, renal abnormal findings were obtained with MRI in 6 patients out of 11 (54.5%), with X-ray CT in 1 patient out of 12 (8.3%), and with the /sup 99m/Tc-DMSA renal scintigraphy in 4 patients out of 6 (66.7%). In the inspections with X-ray CT and renal scintigraphy conducted in 4 weeks, it was noted that the conditions of patients were recovered to the states before ESWL was performed. Using the therapeutic doses of shock wave for humans, the renal parenchymal impairments in the kidney in dogs were normalized in 7 days. Although it has been considered that the degree of renal parenchymal impairments with ESWL treatment may be influenced by the kind of the equipment, frequency of shock waves and their strength, the extent of impairments were rather mild, and it was presumed that the impairments might be recovered on the images in 3 to 4 weeks at the latest. (author).

Studies of renal parenchymal impairments with extracorporeal shock wave lithotripsy (ESWL) by diagnostic imaging methods

International Nuclear Information System (INIS)

Ohishi, Yukihiko; Machida, Toyohei; Tashiro, Kazuya; Wada, Tetsuro; Mochizuki, Atsushi; Torii, Shinichiro; Yoshigoe, Fukuo; Kawashima, Yoshio; Asano, Koji

1989-01-01

Renal parenchymal impairments with extracorporeal shock wave lithotripsy (ESWL) were studied by diagnostic imaging methods. The subjects were 25 patients with renal stones, and EDAP LT-01 (piezoelectric system) was used for the equipment of ESWL. The examination by MRI, X-ray CT and 99m Tc-DMSA scintigraphy using SPECT were performed before and after ESWL. To the 24 kidneys of 12 adult dogs, shock waves were fired in order to examine the experimental renal parenchymal impairments. After the treatment with ESWL, renal abnormal findings were obtained with MRI in 6 patients out of 11 (54.5%), with X-ray CT in 1 patient out of 12 (8.3%), and with the 99m Tc-DMSA renal scintigraphy in 4 patients out of 6 (66.7%). In the inspections with X-ray CT and renal scintigraphy conducted in 4 weeks, it was noted that the conditions of patients were recovered to the states before ESWL was performed. Using the therapeutic doses of shock wave for humans, the renal parenchymal impairments in the kidney in dogs were normalized in 7 days. Although it has been considered that the degree of renal parenchymal impairments with ESWL treatment may be influenced by the kind of the equipment, frequency of shock waves and their strength, the extent of impairments were rather mild, and it was presumed that the impairments might be recovered on the images in 3 to 4 weeks at the latest. (author)

Education for Flexible Personality

Directory of Open Access Journals (Sweden)

Bogomir Novak

1998-12-01

Full Text Available Flexible personality transforms both cultural environment and itself. Post-modern personality is both contemplative and active. On one hand, it is subject to inner imagination of a creative act, and on the other hand, to creation of a tangible product What is more, flexible personality is also autonomous, mature, healthy and well balanced, as well as stable and responsive to the demand for change. Due to ever quicker changes, flexible personality is a must. And it is a task. The impact of professional work of adults on the education of children, however, is being conditioned by the exrigid family and rigid enterprises or institutions in which adults are employed. Nevertheless, flexible educational style is not repressive, as it used to be, nor permissive and totally concentrated on the child. It is a choice between the two qualities. The educators' style is dependent on their attitude towards life (play and self-education and not only towards work. Nowadays, flexibility is a way towards quality management of social and personal changes.

A 970 Hounsfield units (HU) threshold of kidney stone density on non-contrast computed tomography (NCCT) improves patients' selection for extracorporeal shockwave lithotripsy (ESWL): evidence from a prospective study.

Science.gov (United States)

Ouzaid, Idir; Al-qahtani, Said; Dominique, Sébastien; Hupertan, Vincent; Fernandez, Pédro; Hermieu, Jean-François; Delmas, Vincent; Ravery, Vincent

2012-12-01

What's known on the subject? and What does the study add? Stone density on non-contrast computed tomography (NCCT) is reported to be a prognosis factor for extracorporeal shockwave lithotripsy (ESWL). In this prospective study, we determined that a 970 HU threshold of stone density is a very specific and sensitive threshold beyond which the likelihood to be rendered stone free is poor. Thus, NCCT evaluation of stone density before ESWL may useful to identify which patients should be offered alternative treatment to optimise their outcome. • To evaluate the usefulness of measuring urinary calculi attenuation values by non-contrast computed tomography (NCCT) for predicting the outcome of treatment by extracorporeal shockwave lithotripsy (ESWL). • We prospectively evaluated 50 patients with urinary calculi of 5-22 mm undergoing ESWL. • All patients had NCCT at 120 kV and 100 mA on a spiral CT scanner. Patient age, sex, body mass index, stone laterality, stone size, stone attenuation values (Hounsfield units [HU]), stone location, and presence of JJ stent were studied as potential predictors. • The outcome was evaluated 4 weeks after the ESWL session by NCCT. • ESWL success was defined as patients being stone-free (SF) or with remaining stone fragments of ESWL treatment. • Stones of patients who became SF or had CIRF had a lower density compared with stones in patients with residual fragments [mean (sd) 715 (260) vs 1196 (171) HU, P ESWL was identified. • The use of NCCT to determine the attenuation values of urinary calculi before ESWL helps to predict treatment outcome, and, consequently, could be helpful in planning alternative treatment for patients with a likelihood of a poor outcome from ESWL. © 2012 THE AUTHORS. BJU INTERNATIONAL © 2012 BJU INTERNATIONAL.

Graphene-cellulose paper flexible supercapacitors

Energy Technology Data Exchange (ETDEWEB)

Weng, Zhe; Su, Yang; Li, Feng; Du, Jinhong; Cheng, Hui-Ming [Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016 (China); Wang, Da-Wei [ARC Centre of Excellence for Functional Nanomaterials, Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, St Lucia, Brisbane, Qld 4072 (Australia)

2011-10-15

A simple and scalable method to fabricate graphene-cellulose paper (GCP) membranes is reported; these membranes exhibit great advantages as freestanding and binder-free electrodes for flexible supercapacitors. The GCP electrode consists of a unique three-dimensional interwoven structure of graphene nanosheets and cellulose fibers and has excellent mechanical flexibility, good specific capacitance and power performance, and excellent cyclic stability. The electrical conductivity of the GCP membrane shows high stability with a decrease of only 6% after being bent 1000 times. This flexible GCP electrode has a high capacitance per geometric area of 81 mF cm{sup -2}, which is equivalent to a gravimetric capacitance of 120 F g{sup -1} of graphene, and retains >99% capacitance over 5000 cycles. Several types of flexible GCP-based polymer supercapacitors with various architectures are assembled to meet the power-energy requirements of typical flexible or printable electronics. Under highly flexible conditions, the supercapacitors show a high capacitance per geometric area of 46 mF cm{sup -2} for the complete devices. All the results demonstrate that polymer supercapacitors made using GCP membranes are versatile and may be used for flexible and portable micropower devices. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

MiniJFil®: A New Safe and Effective Stent for Well-Tolerated Repeated Extracorporeal Shockwave Lithotripsy or Ureteroscopy for Medium-to-Large Kidney Stones?

Science.gov (United States)

Vogt, Benoit; Desfemmes, Francois-Noel; Desgrippes, Arnaud; Ponsot, Yves

2016-01-01

Background Percutaneous nephrolithotomy (PCNL) is recommended for treating staghorn stones or stones measuring > 20 mm. Extracorporeal shockwave lithotripsy (ESWL) or flexible ureteroscopy (URS) may be used as a complement. However, PCNL can cause trauma to the kidney parenchyma, and patients may find a noninvasive procedure, such as ESWL, to be more attractive. Objectives The aim of this study was to evaluate the clinical efficiency of MiniJFil® stenting associated with ESWL or second-line URS for the treatment of medium-to-large kidney stones. The MiniJFil® is a stent reduced to a suture of 0.3F attached to a renal pigtail. The entire ureter is occupied only by the suture of the stent. Methods We retrospectively analyzed the data of 28 patients. Twenty-four patients had kidney stones measuring > 15 mm (group 1) and four patients had staghorn stones (group 2). All of the patients were fitted with MiniJFil® 2 - 3 weeks before any treatment. ESWL was always our first-line therapy. Stone-free (SF) status was defined as no evidence of stones. Results In group 1, the mean largest and cumulative stone diameters, respectively, were 18.7 ± 5.7 mm and 45.0 ± 12.0 mm. In group 2, the mean volume was 6,288.4 ± 2,733.0 mm3. The overall SF was 96.4% (100% for group 1 and 75% for group 2). The mean number of sessions of ESWL and URS, respectively, was 1.4 ± 0.7 and 0.8 ± 0.9 in group 1 and 4.0 ± 2.0 and 1.5 ± 1.3 in group 2. The mean times to achieve these rates were 3.2 ± 1.7 months and 5.6 ± 2.3 months for groups 1 and 2, respectively. One patient in group 2 was treated with only three sessions of ESWL. Renal colic was observed in only five patients (17.9%). Conclusions MiniJFil® stenting is safe and may be an alternative for the treatment of kidney stones during minimally invasive procedures. PMID:27878116

Radiation exposure during ureteroscopy

International Nuclear Information System (INIS)

Bagley, D.H.; Cubler-Goodman, A.

1990-01-01

Use of fluoroscopy during ureteroscopy increases the risk of radiation exposure to the urologist and patient. Radiation entrance dosages were measured at skin level in 37 patients, and at the neck, trunk and finger of the urologist, and neck and trunk of the circulating nurse. Radiation exposure time was measured in 79 patients, and was related to the purpose of the procedure and the type of ureteroscope used, whether rigid or flexible. Exposure could be minimized by decreasing the fluoroscopy time. A portable C-arm fluoroscopy unit with electronic imaging and last image hold mode should be used to minimize exposure time. Lead aprons and thyroid shields should be used by the urologist and other personnel in the endoscopy room

Three-dimensional formulation of rigid-flexible multibody systems with flexible beam elements

International Nuclear Information System (INIS)

Garcia-Vallejo, D.; Mayo, J.; Escalona, J. L.; Dominguez, J.

2008-01-01

Multibody systems generally contain solids with appreciable deformations and which decisively influence the dynamics of the system. These solids have to be modeled by means of special formulations for flexible solids. At the same time, other solids are of such a high stiffness that they may be considered rigid, which simplifies their modeling. For these reasons, for a rigid-flexible multibody system, two types of formulations coexist in the equations of the system. Among the different possibilities provided in the literature on the material, the formulation in natural coordinates and the formulation in absolute nodal coordinates are utilized in this paper to model the rigid and flexible solids, respectively. This paper contains a mixed formulation based on the possibility of sharing coordinates between a rigid solid and a flexible solid. The global mass matrix of the system is shown to be constant and, in addition, many of the constraint equations obtained upon utilizing these formulations are linear and can be eliminated

Treatment of small lower pole calculi--SWL vs. URS vs. PNL?

Science.gov (United States)

Knoll, Thomas; Tasca, Andrea; Buchholz, Noor P

2011-03-01

According to current guideline recommendations extracorporeal shock wave lithotripsy (SWL) remains the first choice treatment for small and mid-sized renal calculi. However, the results of SWL treatment for lower pole stones can be disappointing whilst more invasive endoscopic modalities, such as flexible ureterorenoscopy (fURS) and percutaneous nephrolithotomy (PNL) are often considered more effective. This article summarizes a point-counterpoint discussion at the 9th eULIS symposium in Como, Italy, and discusses the potential advantages and disadvantages of the different therapeutic approaches.

Development of the Coping Flexibility Scale: Evidence for the Coping Flexibility Hypothesis

Science.gov (United States)

Kato, Tsukasa

2012-01-01

"Coping flexibility" was defined as the ability to discontinue an ineffective coping strategy (i.e., evaluation coping) and produce and implement an alternative coping strategy (i.e., adaptive coping). The Coping Flexibility Scale (CFS) was developed on the basis of this definition. Five studies involving approximately 4,400 Japanese…

A new nomogram for prediction of outcome of pediatric shock-wave lithotripsy.

Science.gov (United States)

Dogan, Hasan Serkan; Altan, Mesut; Citamak, Burak; Bozaci, Ali Cansu; Karabulut, Erdem; Tekgul, Serdar

2015-04-01

Despite the fact that shock-wave lithotripsy (SWL) remains a very good treatment option for smaller stones, it is being challenged by endourologic treatment modalities, which offer similar or even higher success rates in a shorter time, with minimal morbidity and invasiveness. The present study aimed to bring a new and practical insight in order to predict the outcomes of pediatric SWL and to provide objective information about pediatric SWL outcomes. To design a nomogram for predicting the outcomes of pediatric shock-wave lithotripsy. The study was conducted with a retrospective design and included 402 renal units who underwent SWL between January 2009 and August 2013. Patients with known cystine stone disease and cystinuria, with internal or external urinary diversion, were excluded. Analysis was performed on 383 renal units. Postoperative imaging was performed by plain abdominal graphy and ultrasonography with 3-month intervals. Patients who were completely free of stones were considered to be a success and statistical analysis was done regardingly Multivariate analysis was conducted by logistic regression analysis and a nomogram was developed. The male/female distribution was 216/167, with a mean age of 48 ± 40 months and a mean stone size of 9 ± 3.5 mm. The overall stone-free rate was 70% (270/383) and efficacy quotient was 0.57. Mean follow-up was 11 ± 11 months (3-54 months). The number of shock waves and amplitude of energy were higher in failed cases. Multivariate analysis showed that gender, stone size, number of stones, age, location of the stone, and history of previous intervention were found to be the independent prognostic factors for assessing the stone clearance rates. A nomogram was developed using these parameters. In this nomogram, the points achieved from each parameter are summed and total points correspond to the risk of failure in percent. A previous nomogram study by Onal et al. showed that younger age (history, single stone, pelvis or

A randomized controlled trial comparing alpha blocker (tamsulosin) and anticholinergic (solifenacin) in treatment of ureteral stent-related symptoms.

Science.gov (United States)

El-Nahas, Ahmed R; Tharwat, Mohamed; Elsaadany, Mohamed; Mosbah, Ahmed; Gaballah, Mohamed A

2016-07-01

To compare the effectiveness of tamsulosin and solifenacin in relieving ureteral stents related symptoms. A randomized controlled trial was conducted between January 2013 and July 2014. Inclusion criteria were patients aged 20-50 years who underwent temporary unilateral ureteral stent for drainage of calcular upper tract obstruction or after ureteroscopic lithotripsy. Patients with history of lower urinary tract symptoms before stent placement, stents that were fixed after open or laparoscopic procedures, and those who developed complications related to the primary procedure were not included. Eligible patients were randomly assigned to 1 of 3 groups using computer-generated random tables. Patients in group 1 received placebo, patients in group 2 received tamsulosin 0.4 mg once daily, and those in group 3 received solifenacin 5 mg once daily. Ureteral Stent Symptom Questionnaire (USSQ) was answered by all patients 1-2 weeks after stent placement. The primary outcome was the comparison of total score of USSQ between all groups. The study included 131 patients. All baseline characteristics (age, sex, side, indication, length, and duration of stent) were comparable for all groups. Total USSQ score was 61 in solifenacin group, 76 in tamsulosin group, and 83 in control group (P tamsulosin group (P tamsulosin alone or solifenacin alone in patients with ureteral stents can improve the quality of life by decreasing ureteral stent-related symptoms. Solifenacin was better than tamsulosin. CLINICALTRIAL. NCT01880619.

Multiphase fluid-solid coupled analysis of shock-bubble-stone interaction in shockwave lithotripsy.

Science.gov (United States)

Wang, Kevin G

2017-10-01

A novel multiphase fluid-solid-coupled computational framework is applied to investigate the interaction of a kidney stone immersed in liquid with a lithotripsy shock wave (LSW) and a gas bubble near the stone. The main objective is to elucidate the effects of a bubble in the shock path to the elastic and fracture behaviors of the stone. The computational framework couples a finite volume 2-phase computational fluid dynamics solver with a finite element computational solid dynamics solver. The surface of the stone is represented as a dynamic embedded boundary in the computational fluid dynamics solver. The evolution of the bubble surface is captured by solving the level set equation. The interface conditions at the surfaces of the stone and the bubble are enforced through the construction and solution of local fluid-solid and 2-fluid Riemann problems. This computational framework is first verified for 3 example problems including a 1D multimaterial Riemann problem, a 3D shock-stone interaction problem, and a 3D shock-bubble interaction problem. Next, a series of shock-bubble-stone-coupled simulations are presented. This study suggests that the dynamic response of a bubble to LSW varies dramatically depending on its initial size. Bubbles with an initial radius smaller than a threshold collapse within 1 μs after the passage of LSW, whereas larger bubbles do not. For a typical LSW generated by an electrohydraulic lithotripter (p max  = 35.0MPa, p min  =- 10.1MPa), this threshold is approximately 0.12mm. Moreover, this study suggests that a noncollapsing bubble imposes a negative effect on stone fracture as it shields part of the LSW from the stone. On the other hand, a collapsing bubble may promote fracture on the proximal surface of the stone, yet hinder fracture from stone interior. Copyright © 2016 John Wiley & Sons, Ltd.

The Flexibility of Pusher Furnace Grate

Directory of Open Access Journals (Sweden)

Słowik J.A.

2016-12-01

Full Text Available The lifetime of guide grates in pusher furnaces for heat treatment could be increased by raising the flexibility of their structure through, for example, the replacement of straight ribs, parallel to the direction of grate movement, with more flexible segments. The deformability of grates with flexible segments arranged in two orientations, i.e. crosswise (perpendicular to the direction of compression and lengthwise (parallel to the direction of compression, was examined. The compression process was simulated using SolidWorks Simulation program. Relevant regression equations were also derived describing the dependence of force inducing the grate deformation by 0.25 mm ‒ modulus of grate elasticity ‒ on the number of flexible segments in established orientations. These calculations were made in Statistica and Scilab programs. It has been demonstrated that, with the same number of segments, the crosswise orientation of flexible segments increases the grate structure flexibility in a more efficient way than the lengthwise orientation. It has also been proved that a crucial effect on the grate flexibility has only the quantity and orientation of segments (crosswise / lengthwise, while the exact position of segments changes the grate flexibility by less than 1%.

High Performance Electronics on Flexible Silicon

KAUST Repository

Sevilla, Galo T.

2016-09-01

Over the last few years, flexible electronic systems have gained increased attention from researchers around the world because of their potential to create new applications such as flexible displays, flexible energy harvesters, artificial skin, and health monitoring systems that cannot be integrated with conventional wafer based complementary metal oxide semiconductor processes. Most of the current efforts to create flexible high performance devices are based on the use of organic semiconductors. However, inherent material\\'s limitations make them unsuitable for big data processing and high speed communications. The objective of my doctoral dissertation is to develop integration processes that allow the transformation of rigid high performance electronics into flexible ones while maintaining their performance and cost. In this work, two different techniques to transform inorganic complementary metal-oxide-semiconductor electronics into flexible ones have been developed using industry compatible processes. Furthermore, these techniques were used to realize flexible discrete devices and circuits which include metal-oxide-semiconductor field-effect-transistors, the first demonstration of flexible Fin-field-effect-transistors, and metal-oxide-semiconductors-based circuits. Finally, this thesis presents a new technique to package, integrate, and interconnect flexible high performance electronics using low cost additive manufacturing techniques such as 3D printing and inkjet printing. This thesis contains in depth studies on electrical, mechanical, and thermal properties of the fabricated devices.

Workplace flexibility: from research to action.

Science.gov (United States)

Galinsky, Ellen; Sakai, Kelly; Wigton, Tyler

2011-01-01

Ellen Galinsky, Kelly Sakai, and Tyler Wigton explore the "time famine" among American workers-the continuing sense among employees of not having enough time to manage the multiple responsibilities of work and personal and family life. Noting that large shares of U.S. employees report feeling the need for greater workplace flexibility to enable them to take better care of family responsibilities, the authors examine a large-scale community-engagement initiative to increase workplace flexibility voluntarily. Using the 2008 National Study of the Changing Workforce as a primary source of data, the authors begin with an overview of the prevalence of flexibility in today's American workplace. They track which categories of employees have access to various flexibility options, as well as the extent to which employees with access to various types of flexibility use those options. Findings from the study indicate that the majority of employees want flexibility but that access to it varies, with more advantaged employees--those who are well educated, have high salaries, and work full time, for example--being doubly advantaged in having greater access to flexibility. A number of employers, say the authors, tend to be skeptical of the value of workplace flexibility and to fear that employees will abuse it if it is offered. But the study data reveal that most employees use flexibility quite conservatively. When the authors use their nationally representative data set to investigate correlations between access to workplace flexibility and a range of workplace outcomes especially valued by employers--employee engagement, job satisfaction, retention, and health--they find that employers as well as employees can benefit from flexibility. Finally, the authors discuss When Work Works, a large, national community-based initiative under way since 2003 to increase voluntary adoption of workplace flexibility. The authors detail the conceptual basis of the project's design, noting its

Free-form Flexible Lithium-Ion Microbattery

KAUST Repository

Kutbee, Arwa T.; Ghoneim, Mohamed T.; Ahmed, Sally; Hussain, Muhammad Mustafa

2016-01-01

Wearable electronics need miniaturized, safe and flexible power sources. Lithium ion battery is a strong candidate as high performance flexible battery. The development of flexible materials for battery electrodes suffers from the limited material

Cognitive Flexibility in Obsessive Compulsive Disorder

DEFF Research Database (Denmark)

Jónsson, Hjalti; Salkovskis, Paul M.

BT for problems such as OCD requires a level of cognitive flexibility (that is the ability to take a different perspective on ones problems). It could be argued that problems in set shifting (by neuropsychological tests) might underpin problems in this area. Two assessments were used (1: perception...... of cognitive flexibility was assessed by questionnaire 2: neuropsychological evaluation of set shifting). This study will recruit three groups: OCD patients, anxious and healthy controls. Cognitive flexibility is measured using modified version of the Cognitive Flexibility Scale (Martin & Rubin, 1995......) and neuropsychological measures of cognitive flexibility (Wisconsin Cart Sorting Test, Trail Making Test A/B, The Brixton Test). IN addition to the group comparison, the relationship between perceived flexibility, set shifting and psychopathology will be investigated. The implications of the findings for treatment...

Flexible packaging for PV modules

Science.gov (United States)

Dhere, Neelkanth G.

2008-08-01

Economic, flexible packages that provide needed level of protection to organic and some other PV cells over >25-years have not yet been developed. However, flexible packaging is essential in niche large-scale applications. Typical configuration used in flexible photovoltaic (PV) module packaging is transparent frontsheet/encapsulant/PV cells/flexible substrate. Besides flexibility of various components, the solder bonds should also be flexible and resistant to fatigue due to cyclic loading. Flexible front sheets should provide optical transparency, mechanical protection, scratch resistance, dielectric isolation, water resistance, UV stability and adhesion to encapsulant. Examples are Tefzel, Tedlar and Silicone. Dirt can get embedded in soft layers such as silicone and obscure light. Water vapor transmittance rate (WVTR) of polymer films used in the food packaging industry as moisture barriers are ~0.05 g/(m2.day) under ambient conditions. In comparison, light emitting diodes employ packaging components that have WVTR of ~10-6 g/(m2.day). WVTR of polymer sheets can be improved by coating them with dense inorganic/organic multilayers. Ethylene vinyl acetate, an amorphous copolymer used predominantly by the PV industry has very high O2 and H2O diffusivity. Quaternary carbon chains (such as acetate) in a polymer lead to cleavage and loss of adhesional strength at relatively low exposures. Reactivity of PV module components increases in presence of O2 and H2O. Adhesional strength degrades due to the breakdown of structure of polymer by reactive, free radicals formed by high-energy radiation. Free radical formation in polymers is reduced when the aromatic rings are attached at regular intervals. This paper will review flexible packaging for PV modules.

Flexible devices: from materials, architectures to applications

Science.gov (United States)

Zou, Mingzhi; Ma, Yue; Yuan, Xin; Hu, Yi; Liu, Jie; Jin, Zhong

2018-01-01

Flexible devices, such as flexible electronic devices and flexible energy storage devices, have attracted a significant amount of attention in recent years for their potential applications in modern human lives. The development of flexible devices is moving forward rapidly, as the innovation of methods and manufacturing processes has greatly encouraged the research of flexible devices. This review focuses on advanced materials, architecture designs and abundant applications of flexible devices, and discusses the problems and challenges in current situations of flexible devices. We summarize the discovery of novel materials and the design of new architectures for improving the performance of flexible devices. Finally, we introduce the applications of flexible devices as key components in real life. Project supported by the National Key R&D Program of China (Nos. 2017YFA0208200, 2016YFB0700600, 2015CB659300), the National Natural Science Foundation of China (Nos. 21403105, 21573108), and the Fundamental Research Funds for the Central Universities (No. 020514380107).

Developmental constraints on behavioural flexibility.

Science.gov (United States)

Holekamp, Kay E; Swanson, Eli M; Van Meter, Page E

2013-05-19

We suggest that variation in mammalian behavioural flexibility not accounted for by current socioecological models may be explained in part by developmental constraints. From our own work, we provide examples of constraints affecting variation in behavioural flexibility, not only among individuals, but also among species and higher taxonomic units. We first implicate organizational maternal effects of androgens in shaping individual differences in aggressive behaviour emitted by female spotted hyaenas throughout the lifespan. We then compare carnivores and primates with respect to their locomotor and craniofacial adaptations. We inquire whether antagonistic selection pressures on the skull might impose differential functional constraints on evolvability of skulls and brains in these two orders, thus ultimately affecting behavioural flexibility in each group. We suggest that, even when carnivores and primates would theoretically benefit from the same adaptations with respect to behavioural flexibility, carnivores may nevertheless exhibit less behavioural flexibility than primates because of constraints imposed by past adaptations in the morphology of the limbs and skull. Phylogenetic analysis consistent with this idea suggests greater evolutionary lability in relative brain size within families of primates than carnivores. Thus, consideration of developmental constraints may help elucidate variation in mammalian behavioural flexibility.

Flexible Thermoelectric Generators on Silicon Fabric

KAUST Repository

Sevilla, Galo T.

2012-01-01

In this work, the development of a Thermoelectric Generator on Flexible Silicon Fabric is explored to extend silicon electronics for flexible platforms. Low cost, easily deployable plastic based flexible electronics are of great interest for smart

The Flexibility of Organization and the flexibility of product – premises of organizational success

OpenAIRE

Todorut, Amalia Venera

2008-01-01

Flexibility represents the ability of a manufactural system to adapt to some diversified tasks of production, thus to assure an economic efficiency – the rapport time/cost should be optimum, with insignificant structure changes within a long period of time. The central role of flexibility is to permit the survival and the success of the organizations in a turbulent circumstance, which is characteristic to the new world tendencies. The more flexible the organization becomes, the better it resp...

Stenting or not prior to extracorporeal shockwave lithotripsy for ureteral stones? Results of a prospective randomized study.

Science.gov (United States)

Sfoungaristos, Stavros; Polimeros, Nikolaos; Kavouras, Adamantios; Perimenis, Petros

2012-06-01

To determine the need for pre-treatment stenting in patients undergoing extracorporeal shockwave lithotripsy (ESWL) for ureteral stones sized 4-10 mm. A prospective randomized study was conducted between September 2009 and March 2011. Included 156 patients randomized in stented and non-stented groups and underwent a maximum of 3 ESWL sessions. Radiographic follow-up was used to assess the stone fragmentation and clearance. Results were compared in terms of stone-free rates, post-treatment morbidity and complications. Overall efficacy was 76.9%. Stone-free rates were statistically significantly lower (P = 0.026) in the stented group (68.6%) compared to the non-stented ones (83.7%). Furthermore, stenting was significantly correlated with post-treatment lower urinary tract symptoms (P ≤ 0.001), need for more ESWL sessions (P = 0.019) and possibility for operation due to ESWL failure (P = 0.026). A multivariate analysis was conducted to identify the parameters which may predict complete stone removal after ESWL. Stone size (P = 0.026), stone location (P = 0.011) and stenting (P = 0.007) were the most significant factors. ESWL is an efficient and safe treatment for 4- to 10-mm ureteral stones. Pre-treatment stenting is limiting stone-free rates and is significantly influencing post-ESWL morbidity and quality of life in a negative manner, while it contributes minimally to the prophylaxis of complications.

Contagious flexibility? A study on whether schedule flexibility facilitates work-life enrichment.

Science.gov (United States)

Pedersen, Vivi Bach; Jeppesen, Hans Jeppe

2012-08-01

Schedule flexibility defines an important generating resource for work-life enrichment; however, our knowledge about how such spillovers take place is limited. This multiple case study examines how workers from different working time contexts with varying levels of schedule flexibility experience work-life interplay. Given the adopted explorative design, it is important to interpret the findings in a tentative light. Nonetheless, the study offers important insight into work-life enrichment that may guide future research in this field. The findings indicate that schedule flexibility may act as a boundary-spanning resource owing to the agency potential it offers workers. Thus, it seemed that flexible schedule opportunities enabled workers to engage more fully in personal life activities, which in turn had a positive influence on their work involvement through positive affect. Such positive role engagements appeared, however, to be greatly determined by workers' boundary management and by time conditions of work and family. In conclusion, the major findings and limitation of the study are discussed against existing research and theory. © 2012 The Authors. Scandinavian Journal of Psychology © 2012 The Scandinavian Psychological Associations.

Advances in Lasers for the Treatment of Stones-a Systematic Review.

Science.gov (United States)

Kronenberg, Peter; Somani, Bhaskar

2018-05-17

Laser lithotripsy is increasingly used worldwide and is a continuously evolving field with new and extensive research being published every year. Variable pulse length Ho:YAG lithotripters allow new lithotripsy parameters to be manipulated, and there is an effort to integrate new technologies into lithotripters. Pulsed thulium lasers seem to be a viable alternative to holmium lasers. The performance of similar laser fibers varies from manufacturer to manufacturer. Special laser fibers and "cleaving only" fiber tip preparation can be beneficial for the lithotripsy procedure. Different laser settings and the surgical technique employed can have significant impact on the success of laser lithotripsy. When safely done, complications of laser lithotripsy are rare and concern the endoscopic nature of procedure, not the technology itself, making laser lithotripsy one of the safest tools in urology. Laser lithotripsy has had several new developments and more insight has been gained in recent years with many more advances expected in the future.

UNITY OF THE ORGANIZATIONAL FUNCTIONS FLEXIBILITY

OpenAIRE

George MOLDOVEANU; Cosmin DOBRIN

2012-01-01

The paper has the goal to analyse the correlation of the flexibility of all organizational functions. Based upon theoretical and practical studies, the decrease of flexibility into an "activity area" of organizations implies a diminution on a large scale of the flexibility of the processing system as a law expression of the decreasing outputs within economy. Therefore, at the level of each organizational function there are several major directions ensuring the flexibility of the "ensemble".

Prediction of successful treatment by extracorporeal shock wave lithotripsy based on crystalluriacomposition correlations of urinary calculi

Directory of Open Access Journals (Sweden)

Nadia Messaoudi

2015-12-01

Full Text Available Objective: To provide correlations between crystalluria and chemical structure of calculi in situ to help making decision in the use of the extracorporeal shock wave lithotripsy (ESWL. Methods: A crystalluria study was carried out on 644 morning urines of 172 nephrolithiasis patients (111 males and 61 females, and 235 of them were in situ stone carriers. After treating by ESWL, the recovered calculi have been analyzed by Fourier transform infrared spectroscopy and their compositions were correlated to the nature of urinary crystals. Results: We obtained successful treatment for 109 patients out of 157 and 63 patients out of 78 with stones had a treatment failure (33.2%. The correlations showed that for the overwhelming crystalluria containing calcium oxalate dihydrate (COD with mixed crystals without calcium oxalate monohydrate, we should have 68% to 88 % success rate. However, the obtained result was 79%. Similarly, for crystalluria with COD + calcium oxalate monohydrate ± carbapatite, the prediction was 11% to 45% and the result was approximately 39%. When the majority of crystalluria was calcium phosphate, the prediction of 50% to 80% was confirmed by 71% success rate. For those majority containing magnesium ammonium phosphate hexahydrate (struvite ± diammonium urate ± COD, we predicted between 80% to 100%, and the result gave a success rate of 84%. Conclusions: The analysis of crystalluria of morning urine can help to know the composition of calculi in situ and can predict the success rate of ESWL for maximum efficiency.

Effects of previous unsuccessful extracorporeal shockwave lithotripsy treatment on the performance and outcome of percutaneous nephrolithotomy.

Science.gov (United States)

Türk, Hakan; Yoldaş, Mehmet; Süelözgen, Tufan; İşoğlu, Cemal Selcuk; Karabıçak, Mustafa; Ergani, Batuhan; Ün, Sıtkı

2017-06-01

To evaluate the effects of previous unsuccessful extracorporeal shockwave lithotripsy (ESWL) treatment on the performance and outcome of percutaneous nephrolithotomy (PCNL). Of 1625 PCNL procedures performed in our clinic, 393 renal units with similar stone burden and number of accesses was included in the present study. We categorised the study patients into two groups according to whether they underwent ESWL within 1 year prior to PCNL or not. Accordingly, Group 1 comprised 143 (36.3%) ESWL-treated patients and Group 2 comprised 250 (63.7%) non-ESWL-treated patients. Residual stones were detected in 36 (25.1%) of the ESWL-treated patients (Group 1) and in 60 (24%) of non-ESWL-treated patients (Group 2). There were no statistically significant differences between the groups for length of hospital stay (LOS), nephrostomy tube removal time, and the presence of residual stones. When we evaluated the groups for both the preoperative and postoperative haemoglobin (Hb) drop and blood transfusion rate, manifest Hb declines and more transfusions were required in the ESWL-treated patients (both P  = 0.01). In our study, previous ESWL treatment had no influence on the PCNL stone-free rate, operation time, incidence of postoperative complications, and LOS, in patients with similar stone burdens. However, bleeding during PCNL was more prevalent in the ESWL-treated patients, so close attention should be paid to bleeding in patients who have been pretreated with ESWL.

Flexible barrier technology for enabling rollable AMOLED displays and upscaling flexible OLED lighting

NARCIS (Netherlands)

Li, F.M.; Unnikrishnan, S.; Weijer, P. van de; Assche, F. van; Shen, J.; Ellis, T.; Manders, W.; Akkerman, H.; Bouten, P.; Mol, A.M.B. van

2013-01-01

The availability of a high performance thin-film barrier is the most critical challenge in upscaling and commercializing flexible OLED products. We report a flexible thin-film-barrier technology that meets lifetime specifications for OLED lighting, and demonstrate it in rollable QVGA a-IGZO AMOLED

Intrinsic flexibility of porous materials; theory, modelling and the flexibility window of the EMT zeolite framework

International Nuclear Information System (INIS)

Fletcher, Rachel E.; Wells, Stephen A.; Leung, Ka Ming; Edwards, Peter P.; Sartbaeva, Asel

2015-01-01

Framework materials possess intrinsic flexibility which can be investigated using geometric simulation. We review framework flexibility properties in energy materials and present novel results on the flexibility window of the EMT zeolite framework containing 18-crown-6 ether as a structure directing agent (SDA). Framework materials have structures containing strongly bonded polyhedral groups of atoms connected through their vertices. Typically the energy cost for variations of the inter-polyhedral geometry is much less than the cost of distortions of the polyhedra themselves – as in the case of silicates, where the geometry of the SiO 4 tetrahedral group is much more strongly constrained than the Si—O—Si bridging angle. As a result, framework materials frequently display intrinsic flexibility, and their dynamic and static properties are strongly influenced by low-energy collective motions of the polyhedra. Insight into these motions can be obtained in reciprocal space through the ‘rigid unit mode’ (RUM) model, and in real-space through template-based geometric simulations. We briefly review the framework flexibility phenomena in energy-relevant materials, including ionic conductors, perovskites and zeolites. In particular we examine the ‘flexibility window’ phenomenon in zeolites and present novel results on the flexibility window of the EMT framework, which shed light on the role of structure-directing agents. Our key finding is that the crown ether, despite its steric bulk, does not limit the geometric flexibility of the framework

Optimized flexible cover films for improved conversion efficiency in thin film flexible solar cells

Science.gov (United States)

Guterman, Sidney; Wen, Xin; Gudavalli, Ganesh; Rhajbhandari, Pravakar; Dhakal, Tara P.; Wilt, David; Klotzkin, David

2018-05-01

Thin film solar cell technologies are being developed for lower cost and flexible applications. For such technologies, it is desirable to have inexpensive, flexible cover strips. In this paper, we demonstrate that transparent silicone cover glass adhesive can be doped with TiO2 nanoparticles to achieve an optimal refractive index and maximize the performance of the cell. Cells covered with the film doped with nanoparticles at the optimal concentration demonstrated a ∼1% increase in photocurrent over the plain (undoped) film. In addition, fused silica beads can be incorporated into the flexible cover slip to realize a built-in pseudomorphic glass diffuser layer as well. This additional degree of freedom in engineering flexible solar cell covers allows maximal performance from a given cell for minimal increased cost.

Free-form Flexible Lithium-Ion Microbattery

KAUST Repository

Kutbee, Arwa T.

2016-03-02

Wearable electronics need miniaturized, safe and flexible power sources. Lithium ion battery is a strong candidate as high performance flexible battery. The development of flexible materials for battery electrodes suffers from the limited material choices. In this work, we present integration strategy to rationally design materials and processes to report flexible inorganic lithium-ion microbattery with no restrictions on the materials used. The battery shows an enhanced normalized capacity of 147 μAh/cm2 when bent.

Flexible Programmes in Higher Professional Education: Expert Validation of a Flexible Educational Model

Science.gov (United States)

Schellekens, Ad; Paas, Fred; Verbraeck, Alexander; van Merrienboer, Jeroen J. G.

2010-01-01

In a preceding case study, a process-focused demand-driven approach for organising flexible educational programmes in higher professional education (HPE) was developed. Operations management and instructional design contributed to designing a flexible educational model by means of discrete-event simulation. Educational experts validated the model…

Flexible position probe assembly

International Nuclear Information System (INIS)

Schmitz, J.J.

1977-01-01

The combination of a plurality of tubular transducer sections and a flexible supporting member extending through the tubular transducer sections forms a flexible elongated probe of a design suitable for monitoring the level of an element, such as a nuclear magnetically permeable control rod or liquid. 3 claims, 23 figures

Flexible Learning Environments: Leveraging the Affordances of Flexible Delivery and Flexible Learning

Science.gov (United States)

Hill, Janette R.

2006-01-01

The purpose of this article is to explore the key features of "flexible learning environments" (FLEs). Key principles associated with FLEs are explained. Underlying tenets and support mechanisms necessary for the implementation of FLEs are described. Similarities and differences in traditional learning and FLEs are explored. Finally, strategies…

Performance measurement of supply chain flexibility using witness

Directory of Open Access Journals (Sweden)

Rituraj Chandrakar

2012-10-01

Full Text Available In today’s global scenario of intense competition and environmental uncertainty flexibility in supply chain has an important role to play for the existence of any supply chain business. A need to be responsive to the constantly changing market scenario and cater to the customer needs, a certain degree of flexibility is required, which requires the coordination of many plants to produce and deliver goods to customers located in different places, and suppliers, which provide each plant with the required components. This paper intends to measure the degree of flexibility required for a two stage supply chain and assessing both the supplier flexibility and the assembler flexibility. In this paper, nine configurations of the SC are considered resulting from the combination of the three degrees of supplier and manufacturer flexibility, i.e. no flexibility, limited flexibility and total flexibility, respectively. Simulation model representing the different flexibility configurations are evaluated and the performance of each configuration analyzed to determine the flexibility configuration suitable to a supply chain. In particular the performance analysis of lead time, work-in-process, service level and cost are measured to determine the suitable flexibility.

Software industrial flexible

OpenAIRE

Díaz Araya, Daniel; Muñoz, Leandro; Sirerol, Daniel; Oviedo, Sandra; Ibáñez, Francisco S.

2012-01-01

En este trabajo se pretende investigar y proponer técnicas, métodos y tecnologías que permitan el desarrollo de software flexible en ambientes industriales. El objetivo es generar métodos y técnicas para facilitar el desarrollo de software flexible en ambientes industriales. Las áreas de investigación son los sistemas de scheduling de producción, la generación de software para plataformas de hardware abiertas y la innovación.

Flexible Al-doped ZnO films grown on PET substrates using linear facing target sputtering for flexible OLEDs

International Nuclear Information System (INIS)

Jeong, Jin-A; Shin, Hyun-Su; Choi, Kwang-Hyuk; Kim, Han-Ki

2010-01-01

We report the characteristics of flexible Al-doped zinc oxide (AZO) films prepared by a plasma damage-free linear facing target sputtering (LFTS) system on PET substrates for use as a flexible transparent conducting electrode in flexible organic light-emitting diodes (OLEDs). The electrical, optical and structural properties of LFTS-grown flexible AZO electrodes were investigated as a function of dc power. We obtained a flexible AZO film with a sheet resistance of 39 Ω/□ and an average transmittance of 84.86% in the visible range although it was sputtered at room temperature without activation of the Al dopant. Due to the effective confinement of the high-density plasma between the facing AZO targets, the AZO film was deposited on the PET substrate without plasma damage and substrate heating caused by bombardment of energy particles. Moreover, the flexible OLED fabricated on the AZO/PET substrate showed performance similar to the OLED fabricated on a ITO/PET substrate in spite of a lower work function. This indicates that LFTS is a promising plasma damage-free and low-temperature sputtering technique for deposition of flexible and indium-free AZO electrodes for use in cost-efficient flexible OLEDs.

Mechanistic modelling of weak interlayers in flexible and semi-flexible road pavements: Part 2

CSIR Research Space (South Africa)

De Beer, Morris

2012-04-01

Full Text Available This paper (Part 2 of a two-part set of papers) discusses models and illustrates the adverse effects of weak layers, interlayers, laminations and/or weak interfaces in flexible and semi-flexible pavements, also incorporating lightly cemented layers...

Flexible magnetoimpedance sensor

KAUST Repository

Li, Bodong

2015-03-01

Flexible magnetoimpedance (MI) sensors fabricated using a NiFe/Cu/NiFe tri-layer on Kapton substrate have been studied. A customized flexible microstrip transmission line was employed to investigate the MI sensors\\'s magnetic field and frequency responses and their dependence on the sensors\\'s deflection. For the first time, the impedance characteristic is obtained through reflection coefficient analysis over a wide range of frequencies from 0.1 MHz to 3 GHz and for deflections ranging from zero curvature to a radius of 7.2 cm. The sensor element maintains a high MI ratio of up to 90% and magnetic sensitivity of up to 9.2%/Oe over different bending curvatures. The relationship between the curvature and material composition is discussed based on the magnetostriction effect and stress simulations. The sensor\\'s large frequency range, simple fabrication process and high sensitivity provide a great potential for flexible electronics and wireless applications.

THE FLEXIBILITY-AUTOMATION CORRESPONDENCE TO A VIRTUAL COMMERCIAL SOCIETY

Directory of Open Access Journals (Sweden)

Liliana Doble

2012-01-01

Full Text Available Design and operation of FMS is based on system requirement can be as productive and flexible as necessary, i.e. obtaining controlled correspondence between the degree of flexibility and automation of system.The flexibility of a FMS (Flexible Manufacturing Systems is determined by two important criteria: Flexible hardware structure of the system; Flexible software structure. Flexible hardware structure of the CS system (calculation system is determined to its turn according to three components: Flexibility of technological subsystem; Flexibility subsystem of storage, transport and handling;Flexibility of informational subsystem.

Docking of flexible ligands to flexible receptors in solution by molecular dynamics simulation

NARCIS (Netherlands)

Mangoni, R; Roccatano, D; Di Nola, A

1999-01-01

In this paper, a method of simulating the docking of small flexible ligands to flexible receptors in water is reported. The method is based on molecular dynamics simulations and is an extension of an algorithm previously reported by Di Nola et al, (Di Nola et al,, Proteins 1994;19:174-182), The

Propagation of shock waves in elastic solids caused by cavitation microjet impact. II: Application in extracorporeal shock wave lithotripsy.

Science.gov (United States)

Zhong, P; Chuong, C J; Preminger, G M

1993-07-01

To better understand the mechanism of stone fragmentation during extracorporeal shock wave lithotripsy (ESWL), the model developed in Part I [P. Zhong and C.J. Chuong, J. Acoust. Soc. Am. 94, 19-28 (1993)] is applied to study cavitation microjet impingement and its resultant shock wave propagation in renal calculi. Impact pressure at the stone boundary and stress, strain at the propagating shock fronts in the stone were calculated for typical ESWL loading conditions. At the anterior surface of the stone, the jet induced compressive stress can vary from 0.82 approximately 4 times that of the water hammer pressure depending on the contact angles; whereas the jet-induced shear stress can achieve its maximum, with a magnitude of 30% approximately 54% of the water hammer pressure, near the detachment of the longitudinal (or P) wave in the solid. Comparison of model predictions with material failure strengths of renal calculi suggests that jet impact can lead to stone surface erosion by combined compressive and shear loadings at the jet impacting surface, and spalling failure by tensile forces at the distal surface of the stone. Comparing responses from four different stone types suggests that cystine is the most difficult stone to fragment in ESWL, as observed from clinical experience.

Shock wave-bubble interaction near soft and rigid boundaries during lithotripsy: numerical analysis by the improved ghost fluid method

Energy Technology Data Exchange (ETDEWEB)

Kobayashi, Kazumichi [Division of Mechanical and Space Engineering, Faculty of Engineering, Hokkaido University, Kita 13, Nishi 8, Kita-ku, Sapporo, Hokkaido 060-8628 (Japan); Kodama, Tetsuya [Department of Biomedical Engineering, Graduate School of Biomedical Engineering, Tohoku University, 2-1 Seiryo-machi, Aoba-ku, Sendai 980-8575 (Japan); Takahira, Hiroyuki, E-mail: kobakazu@eng.hokudai.ac.jp [Department of Mechanical Engineering, Graduate School of Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai 599-8531 (Japan)

2011-10-07

In the case of extracorporeal shock wave lithotripsy (ESWL), a shock wave-bubble interaction inevitably occurs near the focusing point of stones, resulting in stone fragmentation and subsequent tissue damage. Because shock wave-bubble interactions are high-speed phenomena occurring in tissue consisting of various media with different acoustic impedance values, numerical analysis is an effective method for elucidating the mechanism of these interactions. However, the mechanism has not been examined in detail because, at present, numerical simulations capable of incorporating the acoustic impedance of various tissues do not exist. Here, we show that the improved ghost fluid method (IGFM) can treat shock wave-bubble interactions in various media. Nonspherical bubble collapse near a rigid or soft tissue boundary (stone, liver, gelatin and fat) was analyzed. The reflection wave of an incident shock wave at a tissue boundary was the primary cause for the acceleration or deceleration of bubble collapse. The impulse that was obtained from the temporal evolution of pressure created by the bubble collapse increased the downward velocity of the boundary and caused subsequent boundary deformation. Results of this study showed that the IGFM is a useful method for analyzing the shock wave-bubble interaction near various tissues with different acoustic impedance.

Shock wave-bubble interaction near soft and rigid boundaries during lithotripsy: numerical analysis by the improved ghost fluid method

International Nuclear Information System (INIS)

Kobayashi, Kazumichi; Kodama, Tetsuya; Takahira, Hiroyuki

2011-01-01

In the case of extracorporeal shock wave lithotripsy (ESWL), a shock wave-bubble interaction inevitably occurs near the focusing point of stones, resulting in stone fragmentation and subsequent tissue damage. Because shock wave-bubble interactions are high-speed phenomena occurring in tissue consisting of various media with different acoustic impedance values, numerical analysis is an effective method for elucidating the mechanism of these interactions. However, the mechanism has not been examined in detail because, at present, numerical simulations capable of incorporating the acoustic impedance of various tissues do not exist. Here, we show that the improved ghost fluid method (IGFM) can treat shock wave-bubble interactions in various media. Nonspherical bubble collapse near a rigid or soft tissue boundary (stone, liver, gelatin and fat) was analyzed. The reflection wave of an incident shock wave at a tissue boundary was the primary cause for the acceleration or deceleration of bubble collapse. The impulse that was obtained from the temporal evolution of pressure created by the bubble collapse increased the downward velocity of the boundary and caused subsequent boundary deformation. Results of this study showed that the IGFM is a useful method for analyzing the shock wave-bubble interaction near various tissues with different acoustic impedance.

Shock wave-bubble interaction near soft and rigid boundaries during lithotripsy: numerical analysis by the improved ghost fluid method

Science.gov (United States)

Kobayashi, Kazumichi; Kodama, Tetsuya; Takahira, Hiroyuki

2011-10-01

In the case of extracorporeal shock wave lithotripsy (ESWL), a shock wave-bubble interaction inevitably occurs near the focusing point of stones, resulting in stone fragmentation and subsequent tissue damage. Because shock wave-bubble interactions are high-speed phenomena occurring in tissue consisting of various media with different acoustic impedance values, numerical analysis is an effective method for elucidating the mechanism of these interactions. However, the mechanism has not been examined in detail because, at present, numerical simulations capable of incorporating the acoustic impedance of various tissues do not exist. Here, we show that the improved ghost fluid method (IGFM) can treat shock wave-bubble interactions in various media. Nonspherical bubble collapse near a rigid or soft tissue boundary (stone, liver, gelatin and fat) was analyzed. The reflection wave of an incident shock wave at a tissue boundary was the primary cause for the acceleration or deceleration of bubble collapse. The impulse that was obtained from the temporal evolution of pressure created by the bubble collapse increased the downward velocity of the boundary and caused subsequent boundary deformation. Results of this study showed that the IGFM is a useful method for analyzing the shock wave-bubble interaction near various tissues with different acoustic impedance.

Aggregating and Disaggregating Flexibility Objects

DEFF Research Database (Denmark)

Siksnys, Laurynas; Valsomatzis, Emmanouil; Hose, Katja

2015-01-01

In many scientific and commercial domains we encounter flexibility objects, i.e., objects with explicit flexibilities in a time and an amount dimension (e.g., energy or product amount). Applications of flexibility objects require novel and efficient techniques capable of handling large amounts...... and aiming at energy balancing during aggregation. In more detail, this paper considers the complete life cycle of flex-objects: aggregation, disaggregation, associated requirements, efficient incremental computation, and balance aggregation techniques. Extensive experiments based on real-world data from...

Distributed flexibility in inertial swimmers

Science.gov (United States)

Floryan, Daniel; Rowley, Clarence W.; Smits, Alexander J.

2017-11-01

To achieve fast and efficient swimming, the flexibility of the propulsive surfaces is an important feature. To better understand the effects of distributed flexibility (either through inhomogeneous material properties, varying geometry, or both) we consider the coupled solid and fluid mechanics of the problem. Here, we develop a simplified model of a flexible swimmer, using Euler-Bernoulli theory to describe the solid, Theodorsen's theory to describe the fluid, and a Blasius boundary layer to incorporate viscous effects. Our primary aims are to understand how distributed flexibility affects the thrust production and efficiency of a swimmer with imposed motion at its leading edge. In particular, we examine the modal shapes of the swimmer to gain physical insight into the observed trends. Supported under ONR MURI Grant N00014-14-1-0533, Program Manager Robert Brizzolara.

Flexibility of trunnion piping elbows

International Nuclear Information System (INIS)

Lewis, G.D.; Chao, Y.J.

1987-01-01

Flexibility factors and stress indices for piping component such as straight pipe, elbows, butt-welding tees, branch connections, and butt-welding reducers are contained in the code, but many of the less common piping components, like the trunnion elbow, do not have flexibility factors or stress indices defined. The purpose of this paper is to identify the in-plane and out-of-plane flexibility factors in accordance with code procedures for welded trunnions attached to the tangent centerlines of long radius elbows. This work utilized the finite element method as applicable to plates and shells for calculating the relative rotations of the trunnion elbow-ends for in-plane and out-of-plane elbow moment loadings. These rotations are used to derive the corresponding in-plane and out-of-plane flexibility factors. (orig./GL)

Treatment of upper urinary tract stones with extracorporeal shock wave lithotripsy (ESWL) Sonolith vision.

Science.gov (United States)

Nakamura, Kogenta; Tobiume, Motoi; Narushima, Masahiro; Yoshizawa, Takahiko; Nishikawa, Genya; Kato, Yoshiharu; Katsuda, Remi; Zennami, Kenji; Aoki, Shigeyuki; Yamada, Yoshiaki; Honda, Nobuaki; Sumitomo, Makoto

2011-12-12

The aim was to retrospectively assess the results of treatment of upper urinary tract stones with the Sonolith vision manufactured by EDAP, and purchased in 2004. The subjects were 226 Japanese patients who underwent extracorporeal shock wave lithotripsy (ESWL) alone as an initial treatment and could be followed up for at least 3 months, selected from 277 candidate patients who underwent this therapy between 2004 and 2006. Treatment effect was evaluated by kidney, ureter, and bladder X-ray or renal ultrasonography at 1 and 3 months after treatment. A stone-free status or status of stone fragmentation to 4 mm or smaller was considered to indicate effective treatment. At 3 months after treatment, the stone-free rate was 69.4% and the efficacy rate was 77.4% for renal stones, while these rates were 91.5 and 93.3%, respectively for ureteral stones. Assessment of treatment effect classified by the location of stones revealed a stone-free rate of 94.6% and an efficacy rate of 94.6% for lower ureteral stones (4.0 mm or smaller, 1 subject; 4.1-10.0 mm, 31 subjects; 10.1-20.0 mm, 5 subjects: number of treatment sessions, 1 or 2 sessions [mean: 1.03 sessions]). Complications of this therapy included renal subcapsular hematoma and pyelonephritis in 1 case each. ESWL with the Sonolith vision manufactured by EDAP produced a treatment effect equivalent to those achieved with other models of ESWL equipment. ESWL seems to be an effective first-line treatment also in patients who have lower ureteral stones 10 mm or larger but do not wish to undergo TUL, if measures such as suitable positioning of the patient during treatment are taken.

Treatment of upper urinary tract stones with extracorporeal shock wave lithotripsy (ESWL Sonolith vision

Directory of Open Access Journals (Sweden)

Nakamura Kogenta

2011-12-01

Full Text Available Abstract Background The aim was to retrospectively assess the results of treatment of upper urinary tract stones with the Sonolith vision manufactured by EDAP, and purchased in 2004. Methods The subjects were 226 Japanese patients who underwent extracorporeal shock wave lithotripsy (ESWL alone as an initial treatment and could be followed up for at least 3 months, selected from 277 candidate patients who underwent this therapy between 2004 and 2006. Treatment effect was evaluated by kidney, ureter, and bladder X-ray or renal ultrasonography at 1 and 3 months after treatment. A stone-free status or status of stone fragmentation to 4 mm or smaller was considered to indicate effective treatment. Results At 3 months after treatment, the stone-free rate was 69.4% and the efficacy rate was 77.4% for renal stones, while these rates were 91.5 and 93.3%, respectively for ureteral stones. Assessment of treatment effect classified by the location of stones revealed a stone-free rate of 94.6% and an efficacy rate of 94.6% for lower ureteral stones (4.0 mm or smaller, 1 subject; 4.1-10.0 mm, 31 subjects; 10.1-20.0 mm, 5 subjects: number of treatment sessions, 1 or 2 sessions [mean: 1.03 sessions]. Complications of this therapy included renal subcapsular hematoma and pyelonephritis in 1 case each. Conclusions ESWL with the Sonolith vision manufactured by EDAP produced a treatment effect equivalent to those achieved with other models of ESWL equipment. ESWL seems to be an effective first-line treatment also in patients who have lower ureteral stones 10 mm or larger but do not wish to undergo TUL, if measures such as suitable positioning of the patient during treatment are taken.

Extracorporeal shock wave lithotripsy is safe and effective for pediatric patients with chronic pancreatitis.

Science.gov (United States)

Wang, Dan; Bi, Ya-Wei; Ji, Jun-Tao; Xin, Lei; Pan, Jun; Liao, Zhuan; Du, Ting-Ting; Lin, Jin-Huan; Zhang, Di; Zeng, Xiang-Peng; Ye, Bo; Zou, Wen-Bin; Chen, Hui; Xie, Ting; Li, Bai-Rong; Zheng, Zhao-Hong; Li, Zhao-Shen; Hu, Liang-Hao

2017-05-01

Background and aims  Pancreatic extracorporeal shock wave lithotripsy (P-ESWL) is recommended as the first-line treatment for pancreatic stones. However, how well P-ESWL performs in pediatric patients remains unclear. We aimed to evaluate the safety and efficacy of P-ESWL for pediatric patients with chronic pancreatitis. Methods  This prospective observational study was conducted in patients with painful chronic pancreatitis who underwent P-ESWL. Patients aged under 18 years were included in the pediatric group; patients aged over 18 years who underwent P-ESWL in the same period were assigned to the control group. For investigation of long-term follow-up, the pediatric group were matched with patients from the control group in a 1:1 ratio. The primary outcomes were P-ESWL complications and pain relief. The secondary outcomes included: stone clearance, physical and mental health, quality of life score, and growth and developmental state. Results  From March 2011 to March 2015, P-ESWL was performed in 1135 patients (72 in the pediatric group, 1063 in the control group). No significant differences were observed in the occurrence of P-ESWL complications between the two groups (11.1 % vs. 12.8 %; P  = 0.68). Among the 67 pediatric patients (93.1 %) who underwent follow-up for 3.0 years (range 1.3 - 5.2), complete pain relief was achieved in 52 patients (52 /67; 77.6 %); this value was not significantly different from that of the matched controls (55 /69; 79.7 %; P  = 0.94). Conclusions  P-ESWL is safe and effective for pediatric patients with chronic pancreatitis. It can promote significant pain relief and stone clearance, and can benefit growth and development. © Georg Thieme Verlag KG Stuttgart · New York.

Work Life Balance in the Netherlands: Flexible working hours and a flexible working place (Japanese)

OpenAIRE

KENJOH Eiko

2011-01-01

The purpose of this paper is to investigate the nature of Dutch approach to achieving Work Life Balance (WLB) and to draw policy implications for Japan. It is argued that flexibility of working hours and flexibility offered at one's working place are essential elements of WLB. In this respect, the Netherlands has attained relatively advanced policies and practices. For instance, workers in the Netherlands enjoy a strong degree of flexibility in terms of working hours, a system that strives to...

Business Models for Power System Flexibility

DEFF Research Database (Denmark)

Boscan, Luis; Poudineh, Rahmatallah

2016-01-01

As intermittent, renewable resources gain more share in the generation mix, the need for power system flexibility increases more than ever. Parallel to this, technological change and the emergence of new players bringing about innovative solutions are boosting the development of flexibility...... business models will play an important role in ensuring sufficiency and efficiency of flexibility services....

Comparison of retrograde intrarenal surgery, shockwave lithotripsy, and percutaneous nephrolithotomy for treatment of medium-sized radiolucent renal stones.

Science.gov (United States)

Resorlu, Berkan; Unsal, Ali; Ziypak, Tevfik; Diri, Akif; Atis, Gokhan; Guven, Selcuk; Sancaktutar, Ahmet Ali; Tepeler, Abdulkadir; Bozkurt, Omer Faruk; Oztuna, Derya

2013-12-01

To compare the outcomes of shock wave lithotripsy (SWL), percutaneous nephrolithotomy (PNL), and retrograde intrarenal surgery (RIRS) for 10-20 mm radiolucent renal calculi by evaluating stone-free rates and associated complications. A total of 437 patients at 7 institutions who underwent SWL (n = 251), PNL (n = 140), or RIRS (n = 46) were enrolled in our study. Clinical success was defined as stone-free status or asymptomatic insignificant residual fragments PNL, and RIRS (p PNL and RIRS (21.9 vs 5.7 vs 8.7%, respectively; p PNL, and RIRS were 7.6, 22.1, and 10.9%, respectively (p PNL group received blood transfusions, while none of the patients in RIRS and SWL groups transfused. Hospitalization time per patient was 1.3 ± 0.5 days in the RIRS group, while it was 2.6 ± 0.9 days in the PNL group (p PNL group compared to RIRS (145.7 ± 101.7 vs 28.7 ± 18.7 s, and 57.5 ± 22.1 vs 43.1 ± 17 min, respectively). For treatment of moderate-sized radiolucent renal stones, RIRS and PNL provide significantly higher success and lower retreatment rate compared with SWL. Although PNL is effective, its biggest drawback is its invasiveness. Blood loss, radiation exposure, hospital stay, and morbidities of PNL can be significantly reduced with RIRS technique.

Significance of lower-pole pelvicaliceal anatomy on stone clearance after shockwave lithotripsy in nonobstructive isolated renal pelvic stones.

Science.gov (United States)

Sozen, Sinan; Kupeli, Bora; Acar, Cenk; Gurocak, Serhat; Karaoglan, Ustunol; Bozkirli, Ibrahim

2008-05-01

To investigate the probable effect of lower-pole pelvicaliceal anatomy on stone clearance after shockwave lithotripsy (SWL) in patients with nonobstructive renal pelvic stones. The clinical records of patients with isolated renal pelvic stones who underwent SWL between 1996 and 2005 were reviewed. After excluding patients with obstruction leading to dilatation, major anatomic abnormalities, noncalcium stones, metabolic abnormalities, history of recurrent stone disease, multiple stones, and previous renal surgery, 153 patients were enrolled in the study. Lower pole infundibulopelvic angle (IPA) and infundibular length and width were measured from intravenous urography. Patients were classified into three groups according to stone burden (group 1, renal pelvis, and both in 50 (32.6%), 29 (18.9%), and 8 (5.2%) patients, respectively. There was no statistically significant difference in pelvicaliceal anatomic features except narrower IPA (P=0.02) in group 1 patients with residual stones. The falling of stone fragments to the lower calix in spite of the ureter whether clinically significant or not after SWL of pelvic stones initially seems to be related to stone burden rather than lower caliceal anatomy. However, existence of a more narrow IPA in group 1 patients with residual fragments led us to believe that lower-pole IPA can play a role in stone clearance, especially for smaller stones, probably because of smaller residual fragment size or the more mobile nature of the primary stone.

COMPARISON BETWEEN EXTRACORPOREAL SHOCK WAVE LITHOTRIPSY AT 120 AND 60 SHOCKWAVES PER MINUTE FOR TREATMENT OF URINARY STONES.

Science.gov (United States)

Kashima, Soki; Horikawa, Yohei; Obara, Takashi; Muto, Yumina; Koizumi, Atsushi; Honma, Naoko; Akihama, Susumu; Shimoda, Naotake

2016-01-01

(Purpose) It has recently been suggested that a slow delivery rate of shockwaves by extracorporeal shock wave lithotripsy (SWL) improved treatment outcomes for urinary stones. We retrospectively analyzed the treatment outcomes of different shockwave delivery rates at 120 and 60 shockwaves per minute. (Patients and method) A total of 88 patients were treated at a fast delivery rate of 120 shockwaves per minute between July 2010 and April 2012, and 139 patients were treated at a slow delivery rate of 60 shockwaves per minute between May 2012 and May 2014 (n=227) using a Sonolith ® Praktis lithotripter. The treatment outcome of stone-free rate (SFR) after one SWL session was assessed at four weeks. (Result) SWL at 60 shockwaves per minute resulted in a significantly higher SFR compared with SWL at 120 shockwaves per minute (39.8% and 59.0%, respectively, p=0.0047), particularly for upper ureter (U1) stones (53.1% and 72.0%, respectively, p=0.028). Multivariate analysis showed that younger age, stone sizes of 10 mm or less, U1 stones, and slow delivery rate were significant predictors of a stone-free outcome. There were fewer adverse events after the delivery rate of 60 shockwaves per minute (p=0.058). (Conclusion) Our study suggests that SWL at 60 shockwaves per minute should be recommended to successfully treat urinary stones using the Sonolith ® Praktis lithotripter.

Non-Contrast Computed Tomography Scan Based Parameters of Ureteric Stones Affecting the Outcome of Extracorporeal Shock Wave Lithotripsy

Science.gov (United States)

Ayaz Khan, Mohammad; Waqas Iqbal, Muhammad; Akbar, Mian Khalid; Saqib, Imad-ud-din; Akhter, Saeed

2017-01-01

Objective  To compare the non-contrast computed tomography (NCCT) scan-based parameters of ureteric stones affecting the outcome of extracorporeal shock wave lithotripsy (ESWL). Materials and methods We retrospectively evaluated the pre-procedure NCCT of 74 patients who had ESWL for solitary ureteric calculi of 5-20 mm in diameter. We assessed the age, sex, basal metabolic index (BMI), laterality, location, presence of double 'J' (DJ) stent, skin to stone distance (SSD), stone maximum diameter, Hounsfield unit (HU), Hounsfield density (HD), area, and volume. All those who had no stone on follow-up imaging within 30 days were declared successful while those who had residual stone were declared failures. Results The overall success rate was 78% (58/74). Sixty (81.1%) patients were male. The success of ESWL was correlated with lower SSD, Hounsfield units (HU) and Hounsfield density (HD). However, in multivariate analysis, SSD, Hounsfield unit, and stone area showed correlation with success of procedure but Hounsfield density failed to show correlation. The success rate in patients with stone HU 1000 were 93.9%, 69%, and 58.3%, respectively. Patients with lower BMI (30 kg/m2) and higher HD (>76 HU/mm). Conclusion BMI, SSD, stone Hounsfield units and Hounsfield unit density were strong predictors of outcome of ESWL for ureteric stone. PMID:28589076

Effective radiation exposure evaluation during a one year follow-up of urolithiasis patients after extracorporeal shock wave lithotripsy.

Science.gov (United States)

Kaynar, Mehmet; Tekinarslan, Erdem; Keskin, Suat; Buldu, İbrahim; Sönmez, Mehmet Giray; Karatag, Tuna; Istanbulluoglu, Mustafa Okan

2015-01-01

To determine and evaluate the effective radiation exposure during a one year follow-up of urolithiasis patients following the SWL (extracorporeal shock wave lithotripsy) treatment. Total Effective Radiation Exposure (ERE) doses for each of the 129 patients: 44 kidney stone patients, 41 ureter stone patients, and 44 multiple stone location patients were calculated by adding up the radiation doses of each ionizing radiation session including images (IVU, KUB, CT) throughout a one year follow-up period following the SWL. Total mean ERE values for the kidney stone group was calculated as 15, 91 mSv (5.10-27.60), for the ureter group as 13.32 mSv (5.10-24.70), and in the multiple stone location group as 27.02 mSv (9.41-54.85). There was no statistically significant differences between the kidney and ureter groups in terms of the ERE dose values (p = 0.221) (p >0.05). In the comparison of the kidney and ureter stone groups with the multiple stone location group; however, there was a statistically significant difference (p = 0.000) (p ionized radiation, different imaging modalities with low dose and/or totally without a dose should be employed in the diagnosis, treatment, and follow-up bearing the aim to optimize diagnosis while minimizing the radiation dose as much as possible.

Flexible lithium-ion planer thin-film battery

KAUST Repository

Kutbee, Arwa T.; Ghoneim, Mohamed T.; Hussain, Muhammad Mustafa

2016-01-01

Commercialization of wearable electronics requires miniaturized, flexible power sources. Lithium ion battery is a strong candidate as the next generation high performance flexible battery. The development of flexible materials for battery electrodes

PTFE films with improved flexibility

Science.gov (United States)

Muraca, R. F.; Koch, A. A.

1972-01-01

Development and application of flexible polytetrafluroethylene films for expulsion bladders in spacecraft propellant tanks are described. Flexibility of material is obtained by reducing crystallinity through annealing and quenching in water. Physical and mechanical properties of material are presented.

Predictors for kidney stones recurrence following extracorporeal shock wave lithotripsy (ESWL) or percutaneous nephrolithotomy (PCNL).

Science.gov (United States)

Chongruksut, Wilaiwan; Lojanapiwat, Bannakij; Tawichasri, Chamaiporn; Paichitvichean, Somboon; Euathrongchit, Jantima; Ayudhya, Vorvat Choomsai Na; Patumanond, Jayanton

2012-03-01

Stone recurrence after extracorporeal shock wave lithotripsy (ESWL) or percutaneous nephrolithotomy (PCNL) are common. Predictors for kidney stones vary among populations and areas. To determine predictors for kidney stones recurrence after ESWL or PCNL. A retrospective cohort study was conducted at a university hospital. The study cohort was patients aged more than 18 years, diagnosed with kidney stones, who were treated with ESWL or PCNL between 2006 and 2009. Medical files were reviewed for clinical profiles, stone characteristics, composition, type of treatment, presence of stone after treatment, stone reappearance, and related laboratory data. Predictors were determined by a multivariable poisson regression and presented as incidence rate ratios (IRRs) with 95% confidence interval. From a cohort of 252 patients, 240 who had at least one follow-up and with complete plain kidney ureters and bladder (KUB) film or intravenous pyelogram (IVP) were included in analysis. At three years, the total incidence rate of recurrence was 46 per 1,000 person-months. After a multivariable poisson regression clustering by type of stone composition, independent predictors for stone recurrence were age ESWL treatment (adjusted IRR = 2.1, 95% CI = 2.1-2.2, p < 0.001), stones located in lower calyx as compared to renal pelvis (adjusted IRR = 8.7, 95% CI = 2.9-25.9, p = 0.001), multiple stones (adjusted IRR = 5.9, 95% CI = 4.8-7.5, p < 0.001), and stone size larger than 20 mm (adjusted IRR = 1.4, 95% CI = 1.2-1.6, p < 0.001). After stone removals, patients with these predictors should closely be followed up for regular clinical evaluations.

Consumer Central Energy Flexibility in Office Buildings

DEFF Research Database (Denmark)

Billanes, Joy Dalmacio; Ma, Zheng; Jørgensen, Bo Nørregaard

2017-01-01

Energy flexibility in buildings will play an important role in the smart energy system. Office buildings have more potentials to provide energy flexibility to the grid compared to other types of buildings, due to the existing building management, control systems and large energy consumption....... Consumers in office buildings (building owners/managers and occupants) take a main role for adopting and engaging in building energy flexibility. In this paper provides a systematic review of consumer central energy flexibility in office buildings with the discussion of social, technical and business...... can boost energy flexibility in the office buildings....

Special Issue: Flexible Work Arrangements.

Science.gov (United States)

Olmstead, Barney, Ed.

1996-01-01

Section 1 contains five chapters on flexible work arrangements, self-employment, working from home, part-time professionals, job sharing, and temporary employment. Section 2 includes reviews of four books on working flexibly, concluding with a list of 23 additional readings. (SK)

Symptomatic small non-obstructing lower ureteric calculi: comparison of ureteroscopy and extra corporeal shock wave lithotripsy.

Directory of Open Access Journals (Sweden)

Andankar M

2001-07-01

Full Text Available OBJECTIVE: To compare the success, efficacy and complications of ureteroscopy (URS and extra corporeal shock wave lithotripsy (ESWL for the treatment of symptomatic small non obstructing lower ureteric calculi. SUBJECTS AND METHODS: This prospective non-randomised study was conducted simultaneously at two urological referral centres, included 280 patients with symptomatic small (4-10 mm lower ureteric calculi (situated below the sacroiliac joint, with good renal function on intravenous urography. Patients were offered both the treatment options. One hundred and sixty patients chose ureteroscopy, whereas 120 patients were treated by ESWL. Standard techniques of ureteroscopy and ESWL were employed. Patients were followed-up to assess the success rates and complications of the two procedures. RESULTS: Ureteroscopy achieved complete stone clearance in one session in 95% of patients. In six patients ureteroscopy had failed initially and was later accomplished in second session improving the success rate to 98.7%. Two patients had a proximal migration of calculus that needed ESWL. Of the 120 patients treated by ESWL, 90% achieved stone free status at three months. Ureteroscopy was needed for twelve patients (10% where ESWL failed to achieve stone clearance. There were no significant ESWL related complications. ESWL was administered on outpatient basis, while patients needed hospitalisation and anaesthesia for ureteroscopy. CONCLUSION: ESWL can be the primary mode of treatment for symptomatic small non-obstructing lower ureteric calculi as it is minimally invasive and safe. Ureteroscopy can be offered to patients who demand immediate relief or when ESWL fails.

Flexible displays, rigid designs?

DEFF Research Database (Denmark)

Hornbæk, Kasper

2015-01-01

Rapid technological progress has enabled a wide range of flexible displays for computing devices, but the user experience--which we're only beginning to understand--will be the key driver for successful designs.......Rapid technological progress has enabled a wide range of flexible displays for computing devices, but the user experience--which we're only beginning to understand--will be the key driver for successful designs....

Flexible lithium-ion planer thin-film battery

KAUST Repository

Kutbee, Arwa T.

2016-02-03

Commercialization of wearable electronics requires miniaturized, flexible power sources. Lithium ion battery is a strong candidate as the next generation high performance flexible battery. The development of flexible materials for battery electrodes suffers from the limited material choices. In this work, we present a flexible inorganic lithium-ion battery with no restrictions on the materials used. The battery showed an enhanced normalized capacity of 146 ??Ah/cm2.

Fast and anisotropic flexibility-rigidity index for protein flexibility and fluctuation analysis

Energy Technology Data Exchange (ETDEWEB)

Opron, Kristopher [Department of Biochemistry and Molecular Biology, Michigan State University, Michigan 48824 (United States); Xia, Kelin [Department of Mathematics, Michigan State University, Michigan 48824 (United States); Wei, Guo-Wei, E-mail: wei@math.msu.edu [Department of Biochemistry and Molecular Biology, Michigan State University, Michigan 48824 (United States); Department of Mathematics, Michigan State University, Michigan 48824 (United States); Department of Electrical and Computer Engineering, Michigan State University, Michigan 48824 (United States)

2014-06-21

Protein structural fluctuation, typically measured by Debye-Waller factors, or B-factors, is a manifestation of protein flexibility, which strongly correlates to protein function. The flexibility-rigidity index (FRI) is a newly proposed method for the construction of atomic rigidity functions required in the theory of continuum elasticity with atomic rigidity, which is a new multiscale formalism for describing excessively large biomolecular systems. The FRI method analyzes protein rigidity and flexibility and is capable of predicting protein B-factors without resorting to matrix diagonalization. A fundamental assumption used in the FRI is that protein structures are uniquely determined by various internal and external interactions, while the protein functions, such as stability and flexibility, are solely determined by the structure. As such, one can predict protein flexibility without resorting to the protein interaction Hamiltonian. Consequently, bypassing the matrix diagonalization, the original FRI has a computational complexity of O(N{sup 2}). This work introduces a fast FRI (fFRI) algorithm for the flexibility analysis of large macromolecules. The proposed fFRI further reduces the computational complexity to O(N). Additionally, we propose anisotropic FRI (aFRI) algorithms for the analysis of protein collective dynamics. The aFRI algorithms permit adaptive Hessian matrices, from a completely global 3N × 3N matrix to completely local 3 × 3 matrices. These 3 × 3 matrices, despite being calculated locally, also contain non-local correlation information. Eigenvectors obtained from the proposed aFRI algorithms are able to demonstrate collective motions. Moreover, we investigate the performance of FRI by employing four families of radial basis correlation functions. Both parameter optimized and parameter-free FRI methods are explored. Furthermore, we compare the accuracy and efficiency of FRI with some established approaches to flexibility analysis, namely

Flexibility evaluation of multiechelon supply chains.

Science.gov (United States)

Almeida, João Flávio de Freitas; Conceição, Samuel Vieira; Pinto, Luiz Ricardo; de Camargo, Ricardo Saraiva; Júnior, Gilberto de Miranda

2018-01-01

Multiechelon supply chains are complex logistics systems that require flexibility and coordination at a tactical level to cope with environmental uncertainties in an efficient and effective manner. To cope with these challenges, mathematical programming models are developed to evaluate supply chain flexibility. However, under uncertainty, supply chain models become complex and the scope of flexibility analysis is generally reduced. This paper presents a unified approach that can evaluate the flexibility of a four-echelon supply chain via a robust stochastic programming model. The model simultaneously considers the plans of multiple business divisions such as marketing, logistics, manufacturing, and procurement, whose goals are often conflicting. A numerical example with deterministic parameters is presented to introduce the analysis, and then, the model stochastic parameters are considered to evaluate flexibility. The results of the analysis on supply, manufacturing, and distribution flexibility are presented. Tradeoff analysis of demand variability and service levels is also carried out. The proposed approach facilitates the adoption of different management styles, thus improving supply chain resilience. The model can be extended to contexts pertaining to supply chain disruptions; for example, the model can be used to explore operation strategies when subtle events disrupt supply, manufacturing, or distribution.

Functional aspects of protein flexibility

DEFF Research Database (Denmark)

Teilum, Kaare; Olsen, Johan G; Kragelund, Birthe B

2009-01-01

this into an intuitive perception of protein function is challenging. Flexibility is of overwhelming importance for protein function, and the changes in protein structure during interactions with binding partners can be dramatic. The present review addresses protein flexibility, focusing on protein-ligand interactions...

Skill Flexibility among Schoolteachers: Operationalization and Organizational Implications.

Science.gov (United States)

Rosenblatt, Zehava; Inbal, Batia

1999-01-01

Investigates effects of skill flexibility on Israeli secondary teachers' work attitudes and job performance. Both role and functional flexibility were associated with improved teachers' work performance; role flexibility is linked to high organizational commitment and low powerlessness. Principals appreciate skill flexibility, but organizational…

Flexible labour strategy in the Dutch automotive industry

NARCIS (Netherlands)

van Riemsdijk, Maarten; de Leede, Jan

2001-01-01

Labour flexibility is a major way for companies to become more flexible. Why companies use flexible labour relations varies widely per industry. We assess the development of labour flexibility within the Dutch automotive industry. Four cases, together representing the production chain, are

Endogenous price flexibility and optimal monetary policy

OpenAIRE

Ozge Senay; Alan Sutherland

2014-01-01

Much of the literature on optimal monetary policy uses models in which the degree of nominal price flexibility is exogenous. There are, however, good reasons to suppose that the degree of price flexibility adjusts endogenously to changes in monetary conditions. This article extends the standard new Keynesian model to incorporate an endogenous degree of price flexibility. The model shows that endogenizing the degree of price flexibility tends to shift optimal monetary policy towards complete i...

ESF [Exploratory Shaft Facility] flexibility analysis

International Nuclear Information System (INIS)

Brusenback, R.W.

1987-03-01

This report directs that uncertainty allowances be included within the ESF facilities. The recommendations herein developed are intended as input to Title II Design criteria. Flexibility is measured first by lineal ft of drift, and then by hoisting rate and capacity of supporting utilities and services. A defined probability of need shows an extra 10,000 ft of drift for the first level of flexibility responding to testing and operations, and over 60,000 ft of drift for the second level of flexibility which recognizes possible need for perimeter drifting to investigate geologic stratigraphy. Observing there will be time constraints, a single shaft muck hoisting rate up to 170 to 250 tons per hour is recommended. The potential hoisting rate recommended for flexibility should be satisfied by a hoist approximately equivalent to, or conveniently upgraded from those being considered for sinking and construction, or 1000 horsepower. The cost of flexibility is limited to engineering planning and design (mostly conceptual) which makes later expansion achievable, and to selected items for initial construction where later upgrading would be impractical, impossible, or very costly. The cost is fixed to the level of flexibility and does not vary with excavated footage. The incremental margin is only a small fraction of the additional footage made available. Flexibility presents a strategy and not a position of design or technology. Examples used in this report are intended to be illustrative only, and not to lead design or cost estimates. 7 tabs

Factors impeding flexible inpatient unit design.

Science.gov (United States)

Pati, Debajyoti; Evans, Jennie; Harvey, Thomas E; Bazuin, Doug

2012-01-01

To identify and examine factors extraneous to the design decision-making process that could impede the optimization of flexibility on inpatient units. A 2006 empirical study to identify domains of design decisions that affect flexibility on inpatient units found some indication in the context of the acuity-adaptable operational model that factors extraneous to the design process could have negatively influenced the successful implementation of the model. This raised questions regarding extraneous factors that might influence the successful optimization of flexibility. An exploratory, qualitative method was adopted to examine the question. Stakeholders from five recently built acute care inpatient units participated in the study, which involved three types of data collection: (1) verbal protocol data from a gaming session; (2) in-depth semi-structured interviews; and (3) shadowing frontline personnel. Data collection was conducted between June 2009 and November 2010. The study revealed at least nine factors extraneous to the design process that have the potential to hinder the optimization of flexibility in four domains: (1) systemic; (2) cultural; (3) human; and (4) financial. Flexibility is critical to hospital operations in the new healthcare climate, where cost reduction constitutes a vital target. From this perspective, flexibility and efficiency strategies can be influenced by (1) return on investment, (2) communication, (3) culture change, and (4) problem definition. Extraneous factors identified in this study could also affect flexibility in other care settings; therefore, these findings may be viewed from the overall context of hospital design.

Financial Flexibility as a Phenomenon of Manifestation of Flexibility of the Financial System at the Micro-level

Directory of Open Access Journals (Sweden)

Laktionova Oleksandra A.

2014-03-01

Full Text Available The article considers financial flexibility of economic subjects in the context of specific features of manifestation of this property at the micro-level of the financial system. It generalises various theoretical approaches to understanding the essence of the financial flexibility in the context of motives of its formation, sources and instruments of realisation. It specifies criteria of financial flexibility: manoeuvrability, efficiency and economy. It studies interrelation between the financial flexibility and financial restrictions at the micro-level and, consequently, factors that determine them: capital market imperfection, development level and structure of the financial system, cyclicity of economy, and company characteristics (including financial architecture. The article describes their distinguishing features. It states that apart from maintaining the financial flexibility during formation of money reserves and debt load resource the companies can be guided by other motives. It offers classification of types of financial flexibility based on the sources and goals of formation, influence upon the financial potential, stages of reproduction of financial resources, the instruments used, engaged elements of the financial mechanism, stages of the business cycle and types of the used financial resources.

Flexible learning and the design of instruction

NARCIS (Netherlands)

Collis, Betty; Nikolova, Iliana

1998-01-01

The paper deals with the problem of designing flexible learning and instruction. Flexibility is considered both from the learner's and the designer's perspective. The potential of telematics in the design, development and implementation of flexible and distance learning is discussed. A Method for

A low or high BMI is a risk factor for renal hematoma after extracorporeal shock wave lithotripsy for kidney stones.

Science.gov (United States)

Nussberger, Fabio; Roth, Beat; Metzger, Tobias; Kiss, Bernhard; Thalmann, George N; Seiler, Roland

2017-06-01

The purpose of this study was to evaluate risk factors for renal hematoma after extracorporeal shock wave lithotripsy (SWL) for kidney stones in a matched case-control analysis of a subgroup of patients recruited from a prospective randomized cohort. Between 06/2010 and 03/2013, 418 patients underwent SWL with the MODULITH ® -SLX-F2-lithotripter for kidney stones. In 39/418 patients (9 %), ultrasound at post-treatment day 1 revealed renal hematomas. For 37 of these patients, a matched group without hematoma could be selected according to the following matching criteria: age, gender, number and energy of shock waves, stone burden and localization. Risk factors for renal hematoma after SWL were compared between the two groups. The rates of diabetes, stopped anticoagulant/antiplatelet medications and arterial hypertension were not different between the two groups (p > 0.2). The skin-kidney distance was virtually the same in both groups (p = 0.5). In the hematoma group, significantly more patients had a high (>30: n = 16) as well as a low (hematomas after SWL. Patients with a high (>30) or low (<21.5) BMI had a higher risk for renal damage after SWL. Therefore, alternative endoscopic treatment options should be considered in these patients.

Treatment of Moderate Sized Renal Pelvis Calculi: Stone Clearance Time Comparison of Extracorporeal Shock Wave Lithotripsy and Retrograde Intrarenal Surgery.

Science.gov (United States)

Ercil, Hakan; Alma, Ergun; Bas, Okan; Sener, Nevzat Can; Vuruskan, Ediz; Kuyucu, Faruk; Unal, Umut; Gören, Mehmet Resit; Evliyaoglu, Yalcin

2016-03-05

To compare the stone clearance times in patients undergoing extracorporeal shock wave lithotripsy (SWL) or retrograde intrarenal surgery (RIRS) for single radiopaque renal pelvis stones 10-20 mm in size. The results of this study may guide urologists and patients and aid in selecting the optimal preoperative treatment. Between January 2013 and February 2015, we conducted a retrospective study and collected data from 333 patients treated with SWL (n = 172) or RIRS (n = 161). We included successfully treated patients with a single radiopaque renal pelvis stone 10-20 mm in size to calculate stone clearance times. The average stone size for the SWL group was 14.62 ± 2.58 mm and 14.91 ± 2.92 mm for the RIRS group. The mean Hounsfield unit (HU) of the patients was 585.40 ± 158.39 HU in the SWL group and 567.74 ± 186.85 HU in the RIRS group. Following full fragmentation, the mean stone clearance time was 26.55 ± 9.71 days in the SWL group and 11.59 ± 7.01 days in the RIRS group (P < .001). One of the most overlooked parameters in urinary stone treatments is stone clearance. We believe this study will shed light for those who aim to conduct larger randomized prospective studies. .

Measuring and Comparing Energy Flexibilities

DEFF Research Database (Denmark)

Valsomatzis, Emmanouil; Hose, Katja; Pedersen, Torben Bach

2015-01-01

induced by time and amount individually, and by their com- bination. To this end, we introduce several flexibility measures that take into account the combined effect of time and energy on flex-offer flexibility and discuss their respective pros and cons through a number of realistic examples....

Flexibility evaluation of multiechelon supply chains.

Directory of Open Access Journals (Sweden)

João Flávio de Freitas Almeida

Full Text Available Multiechelon supply chains are complex logistics systems that require flexibility and coordination at a tactical level to cope with environmental uncertainties in an efficient and effective manner. To cope with these challenges, mathematical programming models are developed to evaluate supply chain flexibility. However, under uncertainty, supply chain models become complex and the scope of flexibility analysis is generally reduced. This paper presents a unified approach that can evaluate the flexibility of a four-echelon supply chain via a robust stochastic programming model. The model simultaneously considers the plans of multiple business divisions such as marketing, logistics, manufacturing, and procurement, whose goals are often conflicting. A numerical example with deterministic parameters is presented to introduce the analysis, and then, the model stochastic parameters are considered to evaluate flexibility. The results of the analysis on supply, manufacturing, and distribution flexibility are presented. Tradeoff analysis of demand variability and service levels is also carried out. The proposed approach facilitates the adoption of different management styles, thus improving supply chain resilience. The model can be extended to contexts pertaining to supply chain disruptions; for example, the model can be used to explore operation strategies when subtle events disrupt supply, manufacturing, or distribution.

Flexible Thermoelectric Generators on Silicon Fabric

KAUST Repository

Sevilla, Galo T.

2012-11-01

In this work, the development of a Thermoelectric Generator on Flexible Silicon Fabric is explored to extend silicon electronics for flexible platforms. Low cost, easily deployable plastic based flexible electronics are of great interest for smart textile, wearable electronics and many other exciting applications. However, low thermal budget processing and fundamentally limited electron mobility hinders its potential to be competitive with well established and highly developed silicon technology. The use of silicon in flexible electronics involve expensive and abrasive materials and processes. In this work, high performance flexible thermoelectric energy harvesters are demonstrated from low cost bulk silicon (100) wafers. The fabrication of the micro- harvesters was done using existing silicon processes on silicon (100) and then peeled them off from the original substrate leaving it for reuse. Peeled off silicon has 3.6% thickness of bulk silicon reducing the thermal loss significantly and generating nearly 30% more output power than unpeeled harvesters. The demonstrated generic batch processing shows a pragmatic way of peeling off a whole silicon circuitry after conventional fabrication on bulk silicon wafers for extremely deformable high performance integrated electronics. In summary, by using a novel, low cost process, this work has successfully integrated existing and highly developed fabrication techniques to introduce a flexible energy harvester for sustainable applications.

Flexible and rigid cystoscopy in women.

Science.gov (United States)

Gee, Jason R; Waterman, Bradley J; Jarrard, David F; Hedican, Sean P; Bruskewitz, Reginald C; Nakada, Stephen Y

2009-01-01

Previous studies have evaluated the tolerability of rigid versus flexible cystoscopy in men. Similar studies, however, have not been performed in women. We sought to determine whether office-based flexible cystoscopy was better tolerated than rigid cystoscopy in women. Following full IRB approval, women were prospectively randomized in a single-blind manner. Patients were randomized to flexible or rigid cystoscopy and draped in the lithotomy position to maintain blinding of the study. Questionnaires evaluated discomfort before, during, and after cystoscopy. Thirty-six women were randomized to flexible (18) or rigid (18) cystoscopy. Indications were surveillance (16), hematuria (15), recurrent UTIs (2), voiding dysfunction (1), and other (2). All questionnaires were returned by 31/36 women. Using a 10-point visual analog scale (VAS), median discomfort during the procedure for flexible and rigid cystoscopy were 1.4 and 1.8, respectively, in patients perceiving pain. Median recalled pain 1 week later was similar at 0.8 and 1.15, respectively. None of these differences were statistically significant. Flexible and rigid cystoscopy are well tolerated in women. Discomfort during and after the procedure is minimal in both groups. Urologists should perform either procedure in women based on their preference and skill level.

Flexible magnetic thin films and devices

Science.gov (United States)

Sheng, Ping; Wang, Baomin; Li, Runwei

2018-01-01

Flexible electronic devices are highly attractive for a variety of applications such as flexible circuit boards, solar cells, paper-like displays, and sensitive skin, due to their stretchable, biocompatible, light-weight, portable, and low cost properties. Due to magnetic devices being important parts of electronic devices, it is essential to study the magnetic properties of magnetic thin films and devices fabricated on flexible substrates. In this review, we mainly introduce the recent progress in flexible magnetic thin films and devices, including the study on the stress-dependent magnetic properties of magnetic thin films and devices, and controlling the properties of flexible magnetic films by stress-related multi-fields, and the design and fabrication of flexible magnetic devices. Project supported by the National Key R&D Program of China (No. 2016YFA0201102), the National Natural Science Foundation of China (Nos. 51571208, 51301191, 51525103, 11274321, 11474295, 51401230), the Youth Innovation Promotion Association of the Chinese Academy of Sciences (No. 2016270), the Key Research Program of the Chinese Academy of Sciences (No. KJZD-EW-M05), the Ningbo Major Project for Science and Technology (No. 2014B11011), the Ningbo Science and Technology Innovation Team (No. 2015B11001), and the Ningbo Natural Science Foundation (No. 2015A610110).

Analysis of a Thrust Bearing with Flexible Pads and Flexible Supports

DEFF Research Database (Denmark)

Klit, Peder; Thomsen, Kim

2007-01-01

A theoretical analysis of a hydrodynamic thrust bearing is presented. The bearing investigated is used in an ndustrial product. The lubricant is water, but the results are valid also for other lubricants.At first the results from a 1-dimensional model for the fluid film forces and the associated...... deformation of the bearing geometry is presented. This model enlightens the influence of pad flexibility and support location and flexibility. Subsequently results from a 2-dimensional model of the bearing is presented. The model is used to carry out an optimization of the bearing design, and the obtained...

Flexible Transparent Supercapacitors Based on Hierarchical Nanocomposite Films.

Science.gov (United States)

Chen, Fanhong; Wan, Pengbo; Xu, Haijun; Sun, Xiaoming

2017-05-31

Flexible transparent electronic devices have recently gained immense popularity in smart wearable electronics and touch screen devices, which accelerates the development of the portable power sources with reliable flexibility, robust transparency and integration to couple these electronic devices. For potentially coupled as energy storage modules in various flexible, transparent and portable electronics, the flexible transparent supercapacitors are developed and assembled from hierarchical nanocomposite films of reduced graphene oxide (rGO) and aligned polyaniline (PANI) nanoarrays upon their synergistic advantages. The nanocomposite films are fabricated from in situ PANI nanoarrays preparation in a blended solution of aniline monomers and rGO onto the flexible, transparent, and stably conducting film (FTCF) substrate, which is obtained by coating silver nanowires (Ag NWs) layer with Meyer rod and then coating of rGO layer on polyethylene terephthalate (PET) substrate. Optimization of the transparency, the specific capacitance, and the flexibility resulted in the obtained all-solid state nanocomposite supercapacitors exhibiting enhanced capacitance performance, good cycling stability, excellent flexibility, and superior transparency. It provides promising application prospects for exploiting flexible, low-cost, transparent, and high-performance energy storage devices to be coupled into various flexible, transparent, and wearable electronic devices.

The Flexibility Scale: Development and Preliminary Validation of a Cognitive Flexibility Measure in Children with Autism Spectrum Disorders

Science.gov (United States)

Strang, John F.; Anthony, Laura G.; Yerys, Benjamin E.; Hardy, Kristina K.; Wallace, Gregory L.; Armour, Anna C.; Dudley, Katerina; Kenworthy, Lauren

2017-01-01

Flexibility is a key component of executive function, and is related to everyday functioning and adult outcomes. However, existing informant reports do not densely sample cognitive aspects of flexibility; the Flexibility Scale (FS) was developed to address this gap. This study investigates the validity of the FS in 221 youth with ASD and 57…

Considerations of device and operational flexibility in FER

International Nuclear Information System (INIS)

Sugihara, Masayoshi; Miki, Nobuharu; Nishio, Satoshi; Yamada, Masao; Yamamoto, Shin

1988-01-01

Expected physics uncertainties in DT burning plasma of FER, which may not be removed completely at the start of construction or DT operation, are reviewed. Several possible device and operational flexibility scenarios to cope with these uncertainties are considered. They are (1) Plasma size enlargement scenario, (2) Plasma shape flexibility scenario, (3) Heating/Current drive/Control system flexibility scenario, (4) Impurity control system flexibility scenario and (5) Advanced operation scenario. Feasibility of these flexibility scenarios are examined and shown to be practicable. However, careful assessment of the physics data base is necessary at the start of construction and DT operation to proceed to actually implement these flexibilities in FER. (author)

High-flexibility, noncollapsing lightweight hose

Science.gov (United States)

Williams, D.A.

1993-04-20

A high-flexibility, noncollapsing, lightweight, large-bore, wire-reinforced hose is inside fiber-reinforced PVC tubing that is flexible, lightweight, and abrasion resistant. It provides a strong, kink- and collapse-free conduit for moving large quantities of dangerous fluids, e.g., removing radioactive waste water or processing chemicals.

49 CFR 178.940 - Standards for flexible Large Packagings.

Science.gov (United States)

2010-10-01

.... Flexible Large Packagings types are designated: (1) 51H flexible plastics. (2) 51M flexible paper. (b... this subchapter, flexible Large Packaging must be resistant to aging and degradation caused by ultraviolet radiation. (5) For plastic flexible Large Packagings, if necessary, protection against ultraviolet...

Flexible energy-storage devices: design consideration and recent progress.

Science.gov (United States)

Wang, Xianfu; Lu, Xihong; Liu, Bin; Chen, Di; Tong, Yexiang; Shen, Guozhen

2014-07-23

Flexible energy-storage devices are attracting increasing attention as they show unique promising advantages, such as flexibility, shape diversity, light weight, and so on; these properties enable applications in portable, flexible, and even wearable electronic devices, including soft electronic products, roll-up displays, and wearable devices. Consequently, considerable effort has been made in recent years to fulfill the requirements of future flexible energy-storage devices, and much progress has been witnessed. This review describes the most recent advances in flexible energy-storage devices, including flexible lithium-ion batteries and flexible supercapacitors. The latest successful examples in flexible lithium-ion batteries and their technological innovations and challenges are reviewed first. This is followed by a detailed overview of the recent progress in flexible supercapacitors based on carbon materials and a number of composites and flexible micro-supercapacitors. Some of the latest achievements regarding interesting integrated energy-storage systems are also reviewed. Further research direction is also proposed to surpass existing technological bottle-necks and realize idealized flexible energy-storage devices. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Flexible licensing

Directory of Open Access Journals (Sweden)

Martyn Jansen

2012-07-01

Full Text Available The case is presented for a more flexible approach to licensing online library resources. Today's distributed education environment creates pressure for UK higher and further education institutions (HEI/FEIs to form partnerships and to develop educational products and roll them out across the globe. Online library resources are a key component of distributed education and yet existing licensing agreements struggle to keep pace with the increasing range of users and purposes for which they are required. This article describes the process of developing a flexible approach to licensing and proposes a new model licence for online library resources which has the adaptability needed in this new global educational landscape. These ideas have been presented and discussed at various workshops across Eduserv's and JISC Collections' higher education and publisher communities, and further consultation is ongoing.

Flexible Working Time Arrangements in Bulgaria

OpenAIRE

Beleva, Iskra

2009-01-01

The objective of this paper is to analyze the flexible working time arrangements in Bulgaria, using a life-course perspective. Two important features have to be outlined, namely: underdeveloped flexible forms of employment in the country, including working time arrangement, and lack of previous analysis on flexible working time arrangements from the angle of life-course perspective. The author describes the regulatory framework, collective agreements at national and company level as a frame w...

Sensor Technologies on Flexible Substrates

Science.gov (United States)

Koehne, Jessica

2016-01-01

NASA Ames has developed sensor technologies on flexible substrates integrated into textiles for personalized environment monitoring and human performance evaluation. Current technologies include chemical sensing for gas leak and event monitoring and biological sensors for human health and performance monitoring. Targeted integration include next generation EVA suits and flexible habitats.

Cellulose Nanofiber Composite Substrates for Flexible Electronics

Science.gov (United States)

Ronald Sabo; Jung-Hun Seo; Zhenqiang Ma

2012-01-01

Flexible electronics have a large number of potential applications including malleable displays and wearable computers. The current research into high-speed, flexible electronic substrates employs the use of plastics for the flexible substrate, but these plastics typically have drawbacks, such as high thermal expansion coefficients. Transparent films made from...

[The Feasibility of CT Attenuation Value to Predict the Composition of Upper Urinary Calculi and Success Rate of Extracorporeal Shock Wave Lithotripsy].

Science.gov (United States)

Fan, Yu; Liu, Zhen-Hua; Wei, Qiang; Tang, Zhuang; Liu, Liang-Ren; Ren, Bi-Hua; Li, Xiang; Bao, Yi-Ge; Yang, Lu

2017-09-01

To explore the feasibility of CT attenuation value (CTvalue) to predict the composition of upper urinary calculi and the number of shock waves (NSW) and success rate (SR) of extracorporeal shock wave lithotripsy (ESWL). A total of 146 patients with upper urinary calculi treated by ESWL were included. CT scan was performed before ESWL. Upper urinary calculi with the maximum diameters of less than or equal to 2 cm were included. Infrared spectroscopy was used to analyze the composition of calculi. The effect of ESWL was estimated at 1 month followup. The factors that influence NSW and SR of ESWL were analyzed by correlation analysis. The CTvalue of calcium calculi were larger than that of noncalcium calculi ( P ESWL and CTvalues of calculi between the patients with different ages,skintostone distances and genders were not statistically significant. The partial correlation analysis found that CTvalue and long diameter of calculi were positively correlated with the NSW ( P ESWL ( P ESWL in subgroup analysis. The power of CTvalue to predict upper urinary calculi composition is insufficient. Higher CTvalue suggests more NSW in ESWL,but CTvalue is not suitable to predict SR of ESWL.

Flexible Pedagogies: Employer Engagement and Work-Based Learning. Flexible Pedagogies: Preparing for the Future Series

Science.gov (United States)

Kettle, Jane

2013-01-01

This publication focuses on national and international policy initiatives to develop a better understanding of work-based learners and the types of flexibility that may well enhance their study especially pedagogically. As part of our five-strand research project "Flexible Pedagogies: preparing for the future" it: (1) highlights the…

Bio-Inspired Flexible Cellular Actuating Systems

Science.gov (United States)

2013-11-21

S. Hong, “Robust adaptive boundary control of a flexible marine riser with vessel dynamics,” Automatica, vol. 47, pp. 722–732, 2011. [22] D. H...conditionally accepted. [6] W. He, S. S. Ge, B. V. E. How, Y. S. Choo, and K. S. Hong, “Robust adaptive boundary control of a flexible marine riser ... flexible robotic actuators, often represented by a distributed parameter system or a partial differential equation. We establish a model-guided

Flexible benefit plans in Dutch organisations

OpenAIRE

Hillebrink, C.

2006-01-01

Flexible benefit plans give employees a greater say over the composition of their benefits than traditional Dutch benefit plans. These arrangements developed in a time of further individualisation, increasing flexibility in the workplace, and a tight labour market in the Netherlands. By giving employees a choice in the way they are paid, employers hoped to become more attractive employers, and lend a helping hand to employees who were combining work and care. In this study, flexible benefit p...

Flexible Work Options within the Organisational System

Science.gov (United States)

Albion, Majella J.; Chee, Munli

2006-01-01

The availability of flexible work options provides an opportunity for individuals to shape their careers in order to optimise their work and life goals. This study takes a systems theory approach to examine how the use of flexible work options influences relationships and interactions in the workplace. The "Flexible Work Options…

Limited access: gender, occupational composition, and flexible work scheduling.

Science.gov (United States)

Glauber, Rebecca

2011-01-01

The current study draws on national data to explore differences in access to flexible work scheduling by the gender composition of women's and men's occupations. Results show that those who work in integrated occupations are more likely to have access to flexible scheduling. Women and men do not take jobs with lower pay in return for greater access to flexibility. Instead, jobs with higher pay offer greater flexibility. Integrated occupations tend to offer the greatest access to flexible scheduling because of their structural locations. Part-time work is negatively associated with men's access to flexible scheduling but positively associated with women's access. Women have greater flexibility when they work for large establishments, whereas men have greater flexibility when they work for small establishments.

CT Texture Analysis of Ex Vivo Renal Stones Predicts Ease of Fragmentation with Shockwave Lithotripsy.

Science.gov (United States)

Cui, Helen W; Devlies, Wout; Ravenscroft, Samuel; Heers, Hendrik; Freidin, Andrew J; Cleveland, Robin O; Ganeshan, Balaji; Turney, Benjamin W

2017-07-01

Understanding the factors affecting success of extracorporeal shockwave lithotripsy (SWL) would improve informed decision-making on the most appropriate treatment modality for an individual patient. Although stone size and skin-to-stone distance do correlate with fragmentation efficacy, it has been shown that stone composition and architecture, as reflected by structural heterogeneity on CT, are also important factors. This study aims to determine if CT texture analysis (CTTA), a novel, nondestructive, and objective tool that generates statistical metrics reflecting stone heterogeneity, could have utility in predicting likelihood of SWL success. Seven spontaneously passed, intact renal tract stones, were scanned ex vivo using standard CT KUB and micro-CT. The stones were then fragmented in vitro using a clinical lithotripter, after which, chemical composition analysis was performed. CTTA was used to generate a number of metrics that were correlated to the number of shocks needed to fragment the stone. CTTA metrics reflected stone characteristics and composition, and predicted ease of SWL fragmentation. The strongest correlation with number of shocks required to fragment the stone was mean Hounsfield unit (HU) density (r = 0.806, p = 0.028) and a CTTA metric measuring the entropy of the pixel distribution of the stone image (r = 0.804, p = 0.039). Using multiple linear regression analysis, the best model showed that CTTA metrics of entropy and kurtosis could predict 92% of the outcome of number of shocks needed to fragment the stone. This was superior to using stone volume or density. CTTA metrics entropy and kurtosis have been shown in this experimental ex vivo setting to strongly predict fragmentation by SWL. This warrants further investigation in a larger clinical study for the contribution of CT textural metrics as a measure of stone heterogeneity, along with other known clinical factors, to predict likelihood of SWL success.

Education, Training and the Flexible Labour Market.

Science.gov (United States)

Merson, Martin

1996-01-01

The British government's policy of flexible labor market may be interpreted as either flexibility of conditions, which encourages temporary, contingent work, or flexibility of skills, a repertoire that enables workers to undertake a range of tasks as needed. The challenge for educators is to help workers understand and engage in an uncertain world…

The success of extracorporeal shock-wave lithotripsy based on the stone-attenuation value from non-contrast computed tomography

Science.gov (United States)

Massoud, Amr M.; Abdelbary, Ahmed M.; Al-Dessoukey, Ahmad A.; Moussa, Ayman S.; Zayed, Ahmed S.; Mahmmoud, Osama

2014-01-01

Objective To determine the utility of the urinary stone-attenuation value (SAV, in Hounsfield units, HU) from non-contrast computed tomography (NCCT) for predicting the success of extracorporeal shock-wave lithotripsy (ESWL). Patients and methods The study included 305 patients with renal calculi of ⩽30 mm and upper ureteric calculi of ⩽20 mm. The SAV was measured using NCCT. Numerical variables were compared using a one-way analysis of variance with posthoc multiple two-group comparisons. Univariate and multivariate regression analysis models were used to test the preferential effect of the independent variable(s) on the success of ESWL. Results Patients were grouped according to the SAV as group 1 (⩽500 HU, 81 patients), group 2 (501–1000 HU, 141 patients) and group 3 (>1000 HU, 83 patients). ESWL was successful in 253 patients (83%). The rate of stone clearance was 100% in group 1, 95.7% (135/141) in group 2 and 44.6% (37/83) in group 3 (P = 0.001). Conclusions The SAV value is an independent predictor of the success of ESWL and a useful tool for planning stone treatment. Patients with a SAV ⩾956 HU are not ideal candidates for ESWL. The inclusion criteria for ESWL of stones with a SAV 30 kg/m2 and a lower calyceal location make them less ideal for ESWL. PMID:26019941

Labor Supply Flexibility and Portfolio Choice

OpenAIRE

Zvi Bodie; William Samuelson

1989-01-01

This paper develops a model showing that people who have flexibility in choosing how much to work will prefer to invest substantially more of their money in risky assets than if they had no such flexibility. Viewed in this way, labor supply flexibility offers insurance against adverse investment outcomes. The model provides support for the conventional wisdom that the young can tolerate more risk in their investment portfolios than the old. The model has other implications for the study of ho...

Flexible spin-orbit torque devices

Energy Technology Data Exchange (ETDEWEB)

Lee, OukJae; You, Long; Jang, Jaewon; Subramanian, Vivek [Department of Electrical Engineering and Computer Sciences, University of California at Berkeley, Berkeley, California 94720 (United States); Salahuddin, Sayeef [Department of Electrical Engineering and Computer Sciences, University of California at Berkeley, Berkeley, California 94720 (United States); Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)

2015-12-21

We report on state-of-the-art spintronic devices synthesized and fabricated directly on a flexible organic substrate. Large perpendicular magnetic anisotropy was achieved in ultrathin ferromagnetic heterostructures of Pt/Co/MgO sputtered on a non-rigid plastic substrate at room temperature. Subsequently, a full magnetic reversal of the Co was observed by exploiting the spin orbit coupling in Pt that leads to a spin accumulation at the Pt/Co interface when an in-plane current is applied. Quasi-static measurements show the potential for operating these devices at nano-second speeds. Importantly, the behavior of the devices remained unchanged under varying bending conditions (up to a bending radius of ≈ ±20–30 mm). Furthermore, the devices showed robust operation even after application of 10{sup 6} successive pulses, which is likely sufficient for many flexible applications. Thus, this work demonstrates the potential for integrating high performance spintronic devices on flexible substrates, which could lead to many applications ranging from flexible non-volatile magnetic memory to local magnetic resonance imaging.

Flexible spin-orbit torque devices

International Nuclear Information System (INIS)

Lee, OukJae; You, Long; Jang, Jaewon; Subramanian, Vivek; Salahuddin, Sayeef

2015-01-01

We report on state-of-the-art spintronic devices synthesized and fabricated directly on a flexible organic substrate. Large perpendicular magnetic anisotropy was achieved in ultrathin ferromagnetic heterostructures of Pt/Co/MgO sputtered on a non-rigid plastic substrate at room temperature. Subsequently, a full magnetic reversal of the Co was observed by exploiting the spin orbit coupling in Pt that leads to a spin accumulation at the Pt/Co interface when an in-plane current is applied. Quasi-static measurements show the potential for operating these devices at nano-second speeds. Importantly, the behavior of the devices remained unchanged under varying bending conditions (up to a bending radius of ≈ ±20–30 mm). Furthermore, the devices showed robust operation even after application of 10 6 successive pulses, which is likely sufficient for many flexible applications. Thus, this work demonstrates the potential for integrating high performance spintronic devices on flexible substrates, which could lead to many applications ranging from flexible non-volatile magnetic memory to local magnetic resonance imaging

Can flexibility help you float?

Science.gov (United States)

Burton, L. J.; Bush, J. W. M.

2012-10-01

We consider the role of flexibility in the weight-bearing characteristics of bodies floating at an interface. Specifically, we develop a theoretical model for a two-dimensional thin floating plate that yields the maximum stable plate load and optimal stiffness for weight support. Plates small relative to the capillary length are primarily supported by surface tension, and their weight-bearing potential does not benefit from flexibility. Above a critical size comparable to the capillary length, flexibility assists interfacial flotation. For plates on the order of and larger than the capillary length, deflection from an initially flat shape increases the force resulting from hydrostatic pressure, allowing the plate to support a greater load. In this large plate limit, the shape that bears the most weight is a semicircle, which displaces the most fluid above the plate for a fixed plate length. Exact results for maximum weight-bearing plate shapes are compared to analytic approximations made in the limits of large and small plate sizes. The value of flexibility for floating to a number of biological organisms is discussed in light of our study.

Flexible wings in flapping flight

Science.gov (United States)

Moret, Lionel; Thiria, Benjamin; Zhang, Jun

2007-11-01

We study the effect of passive pitching and flexible deflection of wings on the forward flapping flight. The wings are flapped vertically in water and are allowed to move freely horizontally. The forward speed is chosen by the flapping wing itself by balance of drag and thrust. We show, that by allowing the wing to passively pitch or by adding a flexible extension at its trailing edge, the forward speed is significantly increased. Detailed measurements of wing deflection and passive pitching, together with flow visualization, are used to explain our observations. The advantage of having a wing with finite rigidity/flexibility is discussed as we compare the current results with our biological inspirations such as birds and fish.

Two dimensional nanomaterials for flexible supercapacitors.

Science.gov (United States)

Peng, Xu; Peng, Lele; Wu, Changzheng; Xie, Yi

2014-05-21

Flexible supercapacitors, as one of most promising emerging energy storage devices, are of great interest owing to their high power density with great mechanical compliance, making them very suitable as power back-ups for future stretchable electronics. Two-dimensional (2D) nanomaterials, including the quasi-2D graphene and inorganic graphene-like materials (IGMs), have been greatly explored to providing huge potential for the development of flexible supercapacitors with higher electrochemical performance. This review article is devoted to recent progresses in engineering 2D nanomaterials for flexible supercapacitors, which survey the evolution of electrode materials, recent developments in 2D nanomaterials and their hybrid nanostructures with regulated electrical properties, and the new planar configurations of flexible supercapacitors. Furthermore, a brief discussion on future directions, challenges and opportunities in this fascinating area is also provided.

Flexible nanoscale high-performance FinFETs

KAUST Repository

Sevilla, Galo T.

2014-10-28

With the emergence of the Internet of Things (IoT), flexible high-performance nanoscale electronics are more desired. At the moment, FinFET is the most advanced transistor architecture used in the state-of-the-art microprocessors. Therefore, we show a soft-etch based substrate thinning process to transform silicon-on-insulator (SOI) based nanoscale FinFET into flexible FinFET and then conduct comprehensive electrical characterization under various bending conditions to understand its electrical performance. Our study shows that back-etch based substrate thinning process is gentler than traditional abrasive back-grinding process; it can attain ultraflexibility and the electrical characteristics of the flexible nanoscale FinFET show no performance degradation compared to its rigid bulk counterpart indicating its readiness to be used for flexible high-performance electronics.

Flexibility-enabling Contracts in Electricity Markets

DEFF Research Database (Denmark)

Boscan, Luis; Poudineh, Rahmatallah

As the share of intermittent renewable energy increases in the generation mix, power systems are exposed to greater levels of uncertainty and risk, which requires planners, policy and business decision makers to incentivise flexibility, that is: their adaptability to unforeseen variations....... Additionally, along with traditional sources, which already enable flexibility, a number of business models, such as thermostat-based demand response, aggregators and small storage providers, are emerging in electricity markets and expected to constitute important sources of flexibility in future decentralised...... power systems. However, due to presence of high transaction costs, relative to the size of resource, the emerging small resources cannot directly participate in an organised electricity market and/or compete. This paper asks the fundamental question of how should the provision of flexibility, as a multi...

Evaluation of renal function with dynamic Gd-DTPA enhanced magnetic resonance imaging after shock wave lithotripsy

International Nuclear Information System (INIS)

Izumi, Hirokazu; Shiokawa, Hidefumi; Kurokawa, Jun; Murata, Koichiro; Mashimo, Setsuo; Koshiba, Ken.

1992-01-01

It has already been reported that MR imaging is a superior imaging technique to detect minute anatomical changes in the kidney after extracorporeal shock wave lithotripsy (ESWL). However, the morphological abnormalities found by MR imaging do not necessarily mean deterioration of the renal function. The purpose of this study is to assess the morphological changes in the kidney and changes in renal function after ESWL treatment by dynamic MR imaging. A total of 16 patients underwent axial MR imaging before and after ESWL. Dynamic MR was also performed on 11 patients of them within 24 hours after ESWL, and both before and after ESWL in the remaining 5 patients. Eight kidneys showed morphological abnormalities on T1-weighted images, and 4 of them showed loss of corticomedullary demarcation. Furthermore, the first MR imaging after injection of Gd-DTPA revealed focal areas of decreased signal intensity in only 2 of these 4 patients who showed loss of corticomedullary demarcation on previous MR images. However, the second MR imaging 6 months after ESWL showed no abnormality in either of them. The percent contrast of signal intensity increase to fat signal intensity was one minute after Gd-DTPA injection compared before and after ESWL in 5 of the 16 patients. The values before and after ESWL revealed no statistically significant difference, and no patient showed any remarkable decrease of signal intensity after ESWL. These results suggest that loss of corticomedullary demarcation after ESWL does not necessarily reflect damage to the renal function and that the shock-wave exposure causes no premanent damage to the renal function but only temporary impairment. (author)

Evaluation of renal function with dynamic Gd-DTPA enhanced magnetic resonance imaging after shock wave lithotripsy

Energy Technology Data Exchange (ETDEWEB)

Izumi, Hirokazu; Shiokawa, Hidefumi; Kurokawa, Jun; Murata, Koichiro (Kitasato Inst., Saitama (Japan). Medical Center Hospital); Mashimo, Setsuo; Koshiba, Ken

1992-03-01

It has already been reported that MR imaging is a superior imaging technique to detect minute anatomical changes in the kidney after extracorporeal shock wave lithotripsy (ESWL). However, the morphological abnormalities found by MR imaging do not necessarily mean deterioration of the renal function. The purpose of this study is to assess the morphological changes in the kidney and changes in renal function after ESWL treatment by dynamic MR imaging. A total of 16 patients underwent axial MR imaging before and after ESWL. Dynamic MR was also performed on 11 patients of them within 24 hours after ESWL, and both before and after ESWL in the remaining 5 patients. Eight kidneys showed morphological abnormalities on T1-weighted images, and 4 of them showed loss of corticomedullary demarcation. Furthermore, the first MR imaging after injection of Gd-DTPA revealed focal areas of decreased signal intensity in only 2 of these 4 patients who showed loss of corticomedullary demarcation on previous MR images. However, the second MR imaging 6 months after ESWL showed no abnormality in either of them. The percent contrast of signal intensity increase to fat signal intensity was one minute after Gd-DTPA injection compared before and after ESWL in 5 of the 16 patients. The values before and after ESWL revealed no statistically significant difference, and no patient showed any remarkable decrease of signal intensity after ESWL. These results suggest that loss of corticomedullary demarcation after ESWL does not necessarily reflect damage to the renal function and that the shock-wave exposure causes no premanent damage to the renal function but only temporary impairment. (author).

Impact of Pretreatment Hydronephrosis on the Success Rate of Shock Wave Lithotripsy in Patients with Ureteral Stone.

Science.gov (United States)

Chang, Ki Don; Lee, Joo Yong; Park, Sung Yoon; Kang, Dong Hyuk; Lee, Hyung Ho; Cho, Kang Su

2017-09-01

To evaluate predictors of the success rate for one session of shock wave lithotripsy (SWL), focusing on the relationships between pretreatment hydronephrosis grade and one-session SWL success rates. The medical records of 1824 consecutive patients who underwent an initial session of SWL for treatment of urinary stones between 2005 and 2013 were reviewed. After exclusion, 700 patients with a single, 4-20 mm diameter radiopaque calculus were included in the study. The mean maximal stone length (MSL) and skin-to-stone distance were 9.2±3.9 and 110.8±18.9 mm, respectively. The average values for mean stone density (MSD) and stone heterogeneity index (SHI) were 707.0±272.1 and 244.9±110.1, respectively. One-session success rates were 68.4, 75.0, 75.1, 54.0, and 10.5% in patients with hydronephrosis grade 0, 1, 2, 3, and 4, respectively. Patients were classified into success or failure groups based on SWL outcome. Multivariate logistic regression analyses revealed that MSL [odds ratio (OR) 0.888, 95% confidence intervals (CI): 0.841-0.934, phydronephrosis grade (OR 0.601, 95% CI: 0.368-0.988, p=0.043) were significantly associated with one-session success. Pretreatment grades 3 or 4 hydronephrosis were associated with failure of SWL in patients with a single ureteral stone. In the presence of severe hydronephrosis, especially hydronephrosis grade 4; physicians should proceed cautiously in choosing and offering SWL as the primary treatment for ureteral stone. © Copyright: Yonsei University College of Medicine 2017

Testing of the coping flexibility hypothesis based on the dual-process theory: Relationships between coping flexibility and depressive Symptoms.

Science.gov (United States)

Kato, Tsukasa

2015-12-15

According to the dual-process theory of coping flexibility (Kato, 2012), coping flexibility is the ability to discontinue an ineffective coping strategy (i.e., evaluation coping process) and implement an alternative strategy (i.e., adaptive coping process). The coping flexibility hypothesis (CFH) proposes that the ability to engage in flexible coping is related to better psychological functioning and physical health, including less depression. I the present study, participants were 393 American Whites, 429 Australian Whites, and 496 Chinese, selected from the data pool of the 2013 Coping and Health Survey (see Kato, 2014b). They completed both the Coping Flexibility Scale (Kato, 2012), which is based on the dual-process theory of coping flexibility, and the Center for Epidemiologic Studies Depression Scale (CES-D). For all nationalities and genders, evaluation coping and adaptive coping were significantly correlated with lower levels of depressive symptoms. Structural equation modeling revealed that evaluation coping was associated with lower depressive symptoms for all nationalities and genders, whereas no significant relationships between adaptive coping and depressive symptoms were found for any nationalities. Our results partially supported that the CFH fits with the dual-process theory of coping flexibility. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.