Outcome Of Shock Wave Lithotripsy Research Articles

Comparing non contrast computerized tomography criteria versus dual X-ray absorptiometry as predictors of radio-opaque upper urinary tract stone fragmentation after electromagnetic shockwave lithotripsy

The objective of this study was to assess the value of dual X-ray absorptiometry (DXA) in comparison to non contrast computed tomography (NCCT) density as possible predictors of upper urinary tract stone disintegration by shock wave lithotripsy (SWL). This study included 100 consecutive patients, with solitary renal stone 0.5-2cm or upper ureteral stone up to 1cm. DXA to calculate stone mineral density (SMD) and stone mineral content (SMC) was done. NCCT was performed to measure Hounsfield units (HU). SWL was performed with an electromagnetic lithotripsy, plain X-ray documented disintegration after SWL. Successful treatment was defined as stone free or complete fragmentation after 1 or 2 sessions of SWL. The impact of patients age, sex, body mass index, stone laterality, location, volume, length, mean SMC and SMD, HU and Hounsfield density (HD), skin to stone distance (SSD) and number of shock waves were evaluated by univariate and multivariate analysis. Only 76 patients were available for follow-up. Success of disintegration was observed in 50 out of 76 patients (65.8%). On multivariate analysis, SMC and number of shock wave were the significant independent factors affecting SWL outcome (p=0.04 and p=0.000, respectively). SMC as detected by DXA is a significant predictor of success of stone disintegration by SWL. SMC measured by DXA is more accurate than HU measured by CT. Patients with high stone mineral content (SMC greater than 0.65g) should be directly offered another treatment option.

Time to say good bye to shockwave lithotripsy?

We read with great interest the recent article by Kruck et al. [1] on the comparative study of minimally invasive percutaneous nephrolithotomy (MIP), retrograde intrarenal surgery (RIRS) and shock wave lithotripsy (SWL) in renal stone treatment. In this article, authors compared clinical outcome, complications, stone-free rate (SFR) and stonefree survival with regard to stone size and localization. They concluded the significant advantages of the MIP and RIRS procedures for increased SFRs, lower risk of stone persistence and prolonged stone-free survival compared with SWL. We congratulate the authors for their work and thank them for bringing this debatable topic to our attention; however, we feel that some issues described in their paper need further discussion. Over the last decade, with the miniaturization of instruments in percutaneous nephrolithotomy and technological improvements in flexible ureteroscopes, working instruments and laser technology, RIRS, MIP and microperc techniques have become more attractive procedures for the treatment of nonbulky renal urolithiasis [2, 3]. Furthermore, in the recent years, there has been an increasing realization that the SWL has unpredictable and unfavorable results when comparing with other minimally invasive methods [4–6]. On a comparative study of RIRS and SWL, El-Nahas et al. [4] concluded the significant advantages of the RIRS procedure for higher stone-free rate and lower retreatment rate for the management of medium sized lower pole renal stones. Another three comparative studies, evaluating the outcomes of PNL and SWL, showed that the success rate was statistically higher, and retreatment or auxiliary procedures were less for PNL compared with SWL [5–7]. But in all these studies, PNL or RIRS was associated with an increased risk of complications compared with SWL. Similar results were reported in the present study by Kruck et al. [1]. Despite publishing these studies and clinical treatment guidelines, there are no universally accepted paradigms to treat renal stones, due to absence of robustly designed randomized controlled trials [8, 9]. Until the publishing of welldesigned randomized prospective large series examining the efficacy and safety of minimally invasive treatments, SWL will be the most valuable treatment option because of its noninvasive nature, low morbidity rate and high patient acceptance [3]. Therefore, current EAU guidelines recommend SWL remains the method of first choice for stones \2 cm within the renal pelvis, upper or middle calices and for stones\1.5 cm within lower pole calices [9].

1536 OUTCOME FROM SHOCKWAVE LITHOTRIPSY TO URETERIC CALCULI IN PATIENTS WITH HIGH SKIN-TO-STONE DISTANCE

You have accessJournal of UrologyStone Disease: SWL, Ureteroscopy or Percutaneous Stone Removal (I)1 Apr 20131536 OUTCOME FROM SHOCKWAVE LITHOTRIPSY TO URETERIC CALCULI IN PATIENTS WITH HIGH SKIN-TO-STONE DISTANCE Sara Ramsey, Shirley Wallace, Carolann Stephenson, David Tolley, Ben Thomas, and Simon Phipps Sara RamseySara Ramsey Edinburgh, United Kingdom More articles by this author , Shirley WallaceShirley Wallace Edinburgh, United Kingdom More articles by this author , Carolann StephensonCarolann Stephenson Edinburgh, United Kingdom More articles by this author , David TolleyDavid Tolley Edinburgh, United Kingdom More articles by this author , Ben ThomasBen Thomas Edinburgh, United Kingdom More articles by this author , and Simon PhippsSimon Phipps Edinburgh, United Kingdom More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2013.02.3026AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Obesity is increasingly prevalent and can predispose to nephrolithiasis. The outcome from Shockwave Lithotripsy (SWL) is related to a number of factors including skin-to-stone distance (SSD). The focal depth of many second and third generation lithotriptors is limited to up to 13cm; a number of the latest machines have a greater focal depth. We report the outcomes of SWL to ureteric calculi at an SSD of over 13cm, using a contemporary lithotriptor with a focal depth of up to 17cm. METHODS Patients with a solitary radio-opaque ureteric calculus diagnosed on CT scanning, with an SSD of between 13 and 17cm, were selected from our prospective database. Those with a ureteric stent in situ were excluded. Patients were treated on an outpatient basis with a Sonolith I-Sys Lithotriptor (Vaulx-en-Velin, France) at a frequency of 2Hz using intravenous opiate analgesia if required. Outcome was assessed by a plain KUB XRay at 2 weeks then monthly as required. Further treatment was undertaken if significant fragments remained on post-treatment film. Success was defined as complete clearance of stone fragments. Failure was defined as persistence of stone fragments beyond 3 months or the need for ureteroscopy. Outcomes were assessed on an intention to treat basis. RESULTS 98 patients satisfied the inclusion criteria. Patient and treatment characteristics are shown in table 1. The majority of patients were male, mean age 51, with an upper ureteric stone of mean size 8mm, mean SSD 14cm. 2 patients with lower ureteric stones failed to tolerate treatment. 66 (67%) patients were stone free following a single session of lithotripsy. 24 patients underwent a further session of lithotripsy after which the overall stone free rate rose to 78 (80%). 3 patients were left with small residual fragments requiring no intervention. Overall numbers requiring no further procedure were 83%. 12 patients proceeded to ureteroscopy. Stone free rates were 69% for lower and mid ureteric stones, and 85% for upper ureteric stones. CONCLUSIONS The use of a contemporary lithotriptor in an experienced centre can produce excellent stone free rates following treatment of ureteric calculi in patients with SSDs of 13cm or greater. The use of machines with greater focal depths will allow more patients to undergo SWL for urinary calculi despite increasing obesity. Feature Number Gender Male / Female 87 / 11 Age (Years) Mean, Median, (range) 51, 50, (17-79) Left / right 40 / 58 SSD (cm) Mean, Median, (Range) 14, 14, (13-17) Stone Location PUJ / UU / MU / LU 14 / 68 / 5 / 11 Stone size (mm) Mean, Median, (Range) 9, 8, (4-19) Iv analgesia Yes / No 39 / 59 Localisation Fluoro / USS +Fluoro 70 / 21 Shocks Mean, Median, (Range) 3408, 3674, (464-5221) Sessions of lithotripsy 1 / 2/ 3 72 / 22 / 2 Ureteroscopy No / Yes 86 / 12 © 2013 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 189Issue 4SApril 2013Page: e629-e630 Advertisement Copyright & Permissions© 2013 by American Urological Association Education and Research, Inc.MetricsAuthor Information Sara Ramsey Edinburgh, United Kingdom More articles by this author Shirley Wallace Edinburgh, United Kingdom More articles by this author Carolann Stephenson Edinburgh, United Kingdom More articles by this author David Tolley Edinburgh, United Kingdom More articles by this author Ben Thomas Edinburgh, United Kingdom More articles by this author Simon Phipps Edinburgh, United Kingdom More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Impact of stone density on the outcome of extracorporeal shock wave lithotripsy

Objectives This study aims to evaluate the attenuation of renal calculi measured by Hounsfield unit (HU) by noncontrast spiral computerized tomography (NCSCT) as a predictor of calculus fragmentation by extracorporeal shock wave lithotripsy (SWL). Background The outcome of extracorporeal SWL is measured in terms of stone fragmentation and clearance. Some authors have suggested that HU of renal calculi by NCSCT may predict stone-free rates after extracorporeal SWL. Patients and methods This prospective nonrandomized open study included 100 patients with renal stone up to 20 mm in size. Stone attenuation was measured by HU on NCSCT. Patients were grouped according to stone attenuation as group (1), less than 500 HU, (2), 500-1000 HU, and (3), greater than 1000 HU. Patients were treated subsequently with extracorporeal SWL. The outcome was categorized as stone free, clinically insignificant stone fragments, and residual fragments more than 3 mm. Results The rate of stone fragmentation was 100% (41 of 41 cases) in group 1, 95.7% (44 of 46) in group 2, and 0% (0 of 13) in group 3. A statistically significant association was found between SWL treatment outcome and stone density. When we correlated the absolute stone HU measured with the number of shock waves required for complete fragmentation, we found that the mean number of shock waves was 248 122 in group 1, 334 826 in group 2, and 726 077 in group 3 ( P Conclusion Stone attenuation measured by HU by NCSCT is a predictor of outcome of SWL and suspected number of shock waves required for fragmentation.

Impact of Radiological Technologists on the Outcome of Shock Wave Lithotripsy

Impact of Radiological Technologists on the Outcome of Shock Wave Lithotripsy

The Influence of Stone Size, Skin to Stone Distance and Hydronephrosis on Extracorporeal Shock Wave Lithotripsy Session and Shock Wave Numbers in Ureteral Stones

Background : To evaluate the impact of stone size, grade of hydronephrosis induced by the stone and skin to stone distance (SSD) on the shock wave lithotripsy (SWL) outcome in terms of SWL session and shock wave (SW) numbers in patients with ureteral stones. Methods: Between June 2011 and December 2011, data of 80 patients undergoing SWL for ureteral stones were retrospectively reviewed. Patients were classified into three groups according to hydronephrotic grades (group 1, grade 1 hydronephrosis; group 2, grade 2 hydronephrosis; group 3, grade 3 hydronephrosis) and into two groups according to stone size (group 1, stone size = or < 10 mm and group 2, stone size > 10 mm). The effect of hydronephrotic grade, SSD and stone size on SWL sessions and SW rates were studied. The impact of the stone size on hydronephrosis was also analyzed. Result: Of the 80 patients undergoing SWL, 24 were female and 56 were male. The mean age, stone size, number of sessions, SW rate and SSD were 37.7 (16 - 73), 9.6 mm (6 - 19), 1.65 (1 - 4), 3,812 (1,200 - 8,500) and 9.6 cm (5 - 15) respectively. Thirty-five patients had grade 1, 29 grade 2 and 16 grade 3 hydronephrosis. Twenty-eight patients had upper, 19 mid and 33 lower ureteral stones. There were significant correlation between stone size and SW number (r = 0.513, P < 0.001), and between stone size and session number (r = 0.609, P < 0.001). The correlation between hydronephrotic grade, SW and session numbers was also significant (r = 0.472, P < 0.001 and r = 0.441, P < 0.001). There was no correlation between SSD and SW and session numbers. Four patients with stone size more than 10 mm and grade 2-3 hydronephrosis had unsuccessful SWL outcome. Conclusion: The grade of hydronephrosis and stone size are independent predictive factors for SW and SWL session numbers and indirectly for treatment outcome. SSD was not found to be predictive. World J Nephrol Urol. 2013;2(2):60-64 doi: http://dx.doi.org/10.4021/wjnu127w

Factors Affecting the Outcome of Extracorporeal Shock Wave Lithotripsy for Unilateral Urinary Stones in Children: A 17-Year Single-Institute Experience

PurposeExtracorporeal shock wave lithotripsy (ESWL) is a first-line treatment for pediatric urinary stone disease. We aimed to determine the factors affecting the outcome of ESWL for unilateral urinary stones in children.Materials and MethodsA total of 81 pediatric patients aged 0 to 16 years with urinary stones treated by ESWL from January 1995 through May 2012 were retrospectively reviewed. All patients were required to have unilateral urinary stone disease. Children who underwent other surgical procedures before ESWL were excluded. Outcomes evaluated after ESWL were the stone-free rate at 3 months after ESWL, success within a single session, and success within three sessions. Factors affecting the success within three sessions were also analyzed.ResultsThe final analysis was for 42 boys and 22 girls (mean age, 9.2±5.2 years). Of these 64 patients, 58 (90.6%) were treated by ESWL without other surgical procedures and 54 (84.4%) were successfully treated within three ESWL sessions. In the multivariate analysis, multiplicity (odds ratio [OR], 0.080; 95% confidence interval [CI], 0.012 to 0.534; p=0.009) and large stone size (>10 mm; OR, 0.112; 95% CI, 0.018 to 0.707; p=0.020) were significant factors that decreased the success rate within three ESWL sessions.ConclusionsMost of the pediatric urinary stone patients in our study (90.6%) were successfully treated by ESWL alone without additional procedures. If a child has a large urinary stone (>10 mm) or multiplicity, clinicians should consider that several ESWL sessions might be needed for successful stone fragmentation.

Stone Attenuation Value and Cross-Sectional Area on Computed Tomography Predict the Success of Shock Wave Lithotripsy

PurposeTo identify the parameters on noncontrast computed tomography (NCCT) that best predict the success of shock wave lithotripsy (SWL).Materials and MethodsWe reviewed the records of 75 patients who underwent SWL for urinary calculi measuring 5 to 20 mm. Using NCCT images, we estimated the largest stone cross-sectional area and contoured the inner edge of the stone. Clinical outcome was classified as successful (stone-free or <4 mm in diameter) or failed (stone fragments, ≥4 mm). The impact of preoperative parameters was evaluated by univariate and multivariate analysis.ResultsThe overall success rate was 73.3%. Average stone attenuation value, stone length, and stone cross-sectional area in the success and failure groups were 627.4±166.5 HU (Hounsfield unit) vs. 788.1±233.9 HU (p=0.002), 11.7±3.8 mm vs. 14.2±3.6 mm (p=0.015), and 0.31±0.17 cm2 vs. 0.57±0.41 cm2 (p<0.001), respectively. In the multivariate analysis, stone attenuation value was the only independent predictor of SWL success (p=0.023), although stone cross-sectional area had a tendency to be associated with SWL success (p=0.053). Patients were then classified into four groups by using cutoff values of 780 HU for stone attenuation value and 0.4 cm2 for cross-sectional area. By use of these cutoff values, the group with a low stone attenuation value and a low cross-sectional area was more than 11.6 times as likely to have a successful result on SWL as were all other groups (odds ratio, 11.6; 95% confidence interval, 3.9 to 54.7; p<0.001).ConclusionsStone attenuation value and stone cross-sectional area are good predictors of extracorporeal SWL outcome.

Comparison of retrograde intrarenal surgery, shockwave lithotripsy, and percutaneous nephrolithotomy for treatment of medium-sized radiolucent renal stones

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 <3 mm. The success rates, auxiliary procedures, and complications were compared in each group. Success rates were 66.5, 91.4, and 87% for SWL, PNL, and RIRS (p < 0.001). The need for auxiliary procedures was more common after SWL than PNL and RIRS (21.9 vs 5.7 vs 8.7%, respectively; p < 0.001). The overall complication rates for the SWL, PNL, and RIRS were 7.6, 22.1, and 10.9%, respectively (p < 0.001). Thirteen patients in 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 < 0.001). Fluoroscopy and operation time were significantly longer in the 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.

Effect of size and site on the outcome of extracorporeal shock wave lithotripsy of proximal urinary stones in children

ObjectiveTo determine the effect of location and size of stones on the outcome of extracorporeal shock wave lithotripsy (ESWL) in children. Patients and methodsIn 2008–2010, 150 children (median age 6.6 years) with radio-opaque ureteric and renal stones measuring ≤4 cm were treated. Exclusion criteria were coagulation disorders, pyelonephritis, distal obstruction, non-functioning kidney and hypertension. ESWL was performed under general anesthesia. Follow up period was 5–22 months. Results186 stones were treated: 76 calyceal, 92 pelvic and 18 proximal ureteral. Mean stone size was 1.3 cm. A total of 312 sessions were performed (mean per stone = 1.67 sessions). The mean number of shock waves per session was 2423.68. Overall stone-free rate was 89.24%. Having a calyceal location did not significantly affect the stone-free rate (p = 0.133). The failure rate was significantly higher (66.7%) in stones >3 cm in size (p < 0.001). Complications were encountered in 18 patients; 2 underwent auxillary ureteroscopy and 4 uretrolithotomy for treatment of steinstrasse. ConclusionESWL is a safe and effective method for treatment of stones up to 2 cm in children. Rate of auxillary procedures increases in stones >2 cm in size. About 80% of failures were associated with stone size >1.35 cm while 52.3% of completely cleared stones were associated with size <1.35 cm.

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

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.

Flexible ureterorenoscopy versus extracorporeal shock wave lithotripsy for treatment of lower pole stones of 10–20 mm

What's known on the subject? and What does the study add? Shock wave lithotripsy and flexible ureterorenoscopy are acceptable treatment options for lower pole stones smaller than 10 mm, while percutaneous nephrolithotomy is the favoured treatment for stones larger than 20 mm. For treatment of lower pole stones of 10-20 mm, flexible ureterorenoscopy has a significantly higher stone-free rate and lower retreatment rate than shock wave lithotripsy. To compare the outcomes of flexible ureterorenoscopy (F-URS) and extracorporeal shock wave lithotripsy (ESWL) for treatment of lower pole stones of 10-20 mm. The database of patients with a single lower pole stone of 10-20 mm was examined to obtain two matched groups who were treated with F-URS or ESWL. Matching criteria were stone length, side and patient gender. Stone-free rates were evaluated 3 months after the last treatment session by non-contrast computed tomography. Both groups were compared for retreatment rate, complications and stone-free rate. The matched groups included 37 patients who underwent F-URS and 62 patients who underwent ESWL. Retreatment rate was significantly higher for ESWL (60% vs 8%, P < 0.001). Complications were more after F-URS (13.5% vs 4.8%), but the difference was not significant (P= 0.146). All complications were grade II or IIIa on modified Clavien classification. The stone-free rate was significantly better after F-URS (86.5% vs 67.7%, P= 0.038). One failure of F-URS (2.7%) and five failures (8%) of ESWL were treated with percutaneous nephrolithotomy. Significant residual fragments in three patients (8%) after F-URS were treated with ESWL, while significant residual fragments after ESWL in five patients (8%) were treated with F-URS. Residual fragments (<4 mm) were followed every 3 months in one patient (2.7%) after F-URS and in 10 patients (16%) after ESWL. For treatment of lower pole stones of 10-20 mm, F-URS provided significantly higher stone-free rate and lower retreatment rate compared with ESWL. The incidence of complications after F-URS was not significantly more than after ESWL.

Non-Contrast Computed Tomography Scan as a Predictor of Shock-Wave Lithotripsy Outcomes for the Treatment of Renal Stones

Non-Contrast Computed Tomography Scan as a Predictor of Shock-Wave Lithotripsy Outcomes for the Treatment of Renal Stones

Which Is More Important in Predicting the Outcome of Extracorporeal Shockwave Lithotripsy of Solitary Renal Stones: Stone Location or Stone Burden?

To assess the effect of stone location and burden on the outcome of extracorporeal shockwave lithotripsy (SWL) as a primary treatment of solitary renal stone. The study included 438 patients with a solitary renal stone who underwent SWL as a primary treatment for their stones. All were evaluated by plain radiography of the kidneys, ureters, and bladder (KUB), ultrasonography, intravenous urography, or noncontrast enhanced CT before SWL and followed up for 3 months after treatment by KUB radiography and/or ultrasonography. Patients were classified into four groups according to stone location (renal pelvis, lower, middle, and upper calix) and three groups according to stone burden (≤ 1 cm(2), 1.1-2 cm(2), and >2 cm(2)). Treatment outcome was considered successful if no residual fragments (stone free) or clinically insignificant nonobstructing residuals less than 4 mm remained after 3 months of follow-up. The mean age of the patients was 45.1 ± 12.5 years. The mean stone burden, number of sessions, and shockwaves for the whole study were 1.3 ± 0.49 cm(2), 2.1 ± 0.7 sessions, and 5616.6 ± 2017.4 shockwaves, respectively. The stone-free rate of the study was 65.1%. The stone-free rates of the stones in the renal pelvis, lower, middle, and upper calices were 72.4%, 56%, 55.6%, and 69%, respectively. The stone-free rate of the stones ≤ 1 cm(2), 1.1 to 2 cm(2), and >2 cm(2) was 50.2%, 39.6%, and 10.2%, respectively (P<0.05). Stone burden rather than stone location is considered as a predicting factor for the outcome of SWL in a solitary renal stone, especially in the renal pelvis and lower calix.

Impact of Radiological Technologists on the Outcome of Shock Wave Lithotripsy

To evaluate the correlation of radiological technologists (RTs) and the outcome of shock wave lithotripsy (SWL) in terms of fluoroscopy time, fragmentation rate, and stone-free rate. A retrospective review of a prospectively collected database of 601 SWL treatments between June 2009 and March 2010 was performed. Patients with radiolucent stones were excluded. SWL was done by 6 RTs with different levels of experience. Follow up was available for 534 treatments. Multivariate analysis was performed. RTs (A-F) performed 144, 109, 118, 58, 57, and 48 SWL sessions, respectively. There was no statistical difference among RTs in terms of mean stone size or stone location. Compared with other RTs, RT A had a significantly lower mean fluoroscopy time of 129 seconds (95% CI 120.8-137.3) (P <.001), higher stone-free rate (75.7%; P = .035), and stone fragmentation rate after a single SWL session (82.6%; P = .004). After correcting for stone size and location, fluoroscopy time (P <.001), fragmentation rate (P = .002), and stone-free rate (P = .04) maintained their significance. When comparing the top 3 RTs performing >100 SWL sessions, RTs B and C had significantly higher fluoroscopy time compared with RT A (OR [95% CI] 1.84 [1.38-2.45]; P <.001 and 2.67 [2.00-3.57]; P <.001), respectively. After correcting for stone size and location, RT B had significantly lower fragmentation rate when compared with RT A (OR [95% CI] 0.21 [0.05-0.86], P = .03]. However, there were no significant differences among the top 3 RTs in terms of stone-free rates. RTs significantly differ in fluoroscopy usage in addition to stone fragmentation and stone-free rates.

UP-03.076 Safer and More Efficient Shock Wave Lithotripsy (SWL) Using Dornier Lithotripter S II

In August 1984, Sanjukai Hospital started the very first case of shock wave lithotripsy (SWL) in Japan as a minimally-invasive treatment, and has been one of the leading institutes of stone treatment for these past 27 years. We retrospectively reviewed the treatment outcomes of SWL in our single institute using Dornier HM3 (HM3; 1984-2009), Philips Litho Diagnost M (LDM; 1994-2008), and Dornier Lithotripter S II (S II; 2009-2010), and analyzed recent efficiencies and adverse effects of SWL using the new S II compared with our historical controls using LDM and HM3.

Comparison of Efficacy of German and Chinese Electromagnetic Shock Wave Lithotripters: Dornier Compact S vs Huikang MZ-SWL-V

To compare the treatment efficacy of Dornier Compact S and a Chinese electromagnetic shock wave lithotripter (Huikang MZ-SWL-V) in a large series. We retrospectively reviewed the outcome of shock wave lithotripsy (SWL) in 13,954 consecutive patients with upper urinary tract stones from December 1996 to December 2008 with Dornier Compact S (9124 cases) and Huikang MZ-SWL-V (4830 cases). An intramuscular injection of 50 mg pethidine was given to the patients with Dornier Compact S but not to those with Huikang MZ-SWL-V. Treatment outcomes were assessed by the stone-free rate at three months, the retreatment rate, the auxiliary procedure rate, and the effectiveness quotient. The pain scores were evaluated by visual analog scales, where 0 = pain and 10 = unbearable pain. The overall stone-free rate at 3 months, retreatment rate, and ancillary procedure rate for Dornier Compact S were 95.9%, 13.4%, and 2.2%, respectively, and they were 85%, 29.6%, and 10.2%, respectively, for Huikang MZ-SWL-V. The overall efficiency quotients of Dornier Compact S and Huikang MZ-SWL-V were 83% and 60.8%, respectively. However, the pain scores in the Dornier group (6-10) were higher than those in the Huikang group (1-5). Three clinically significant subcapsular hematomas were detected in the Dornier group but there were none in the Huikang group. Dornier Compact S is more effective than Huikang MZ-SWL-V, but SWL with Huikang machine could be performed with milder pain and without analgesia, and a lower significant hematoma rate was observed in Huikang group.

A Clinical Nomogram to Predict the Successful Shock Wave Lithotripsy of Renal and Ureteral Calculi

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 (p<0.01), mean stone density (p<0.01) and skin to stone distance (p<0.01). By multivariate logistic regression for renal calculi, age, stone 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.

Percutaneous Nephrolithotomy Versus Extracorporeal Shock Wave Lithotripsy for Moderate Sized Kidney Stones

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.

Predicting the fragility of renal calculi in response to shock wave lithotripsy through their radiographic appearance

To evaluate the radiological characteristics of renal stones on plain X-ray film of the kidneys, ureters and bladder (KUB) area as predictors of stone fragility during shock wave lithotripsy (SWL). This prospective study included 336 patients who had a single renal pelvic stone ≤20 mm and were managed by SWL at 3 different centers. The patients were classified according to the radiological appearance of the stone on KUB film in terms of homogeneity, smoothness of the outline, and radiodensity in comparison to the last rib. The primary endpoint was the stone-free rate (SFR) within 3 months post-SWL. Multivariate regression analysis was used to compare the results. The overall SFR was 71.43%. SFR was significantly higher in heterogeneous compared with homogenous stones (86% vs. 53%; p<0.01) and in rough compared with smooth surface calculi (77% vs. 61%, p<0.01). SFRs for stones with density less than, similar to or higher than that of the last rib were 82%, 69% and 56%, respectively (p<0.01). Multivariate analysis showed a positive proportional relationship between stone fragility (SWL outcome) and one or more favorable radiological criteria. The radiological characteristics of renal calculi could predict their fragility after SWL. Stones which were heterogeneous, rough, or less dense than the last rib on KUB film were more likely to disintegrate during SWL.