Failed Shock Wave Lithotripsy Research Articles

External validation of a nomogram for outcome prediction in management of medium-sized (1-2 cm) kidney stones.

Stone nomogram by Micali et al., able topredict treatment failure of shock-wave lithotripsy (SWL), retrograde intrarenal surgery (RIRS) and percutaneous nephrolithotomy (PNL) in the management of single 1-2 cm renal stones, was developed on 2605 patients and showed a high predictive accuracy, with an area under ROC curve of 0.793 at internal validation. The aim of the present study is to externally validate the model to assess whether it displayed a satisfactory predictive performance if applied to different populations. External validation was retrospectively performed on 3025 patients who underwent an active stone treatment from December 2010 to June 2021 in 26 centers from four countries (Italy, USA, Spain, Argentina). Collected variables included: age, gender, previous renal surgery, preoperative urine culture, hydronephrosis, stone side, site, density, skin-to-stone distance. Treatment failure was the defined outcome (residual fragments >4 mm at three months CT-scan). Model discrimination in external validation datasets showed an area under ROC curve of 0.66 (95% 0.59-0.68) with adequate calibration. The retrospective fashion of the study and the lack of generalizability of the tool towards populations from Asia, Africa or Oceania represent limitations of the current analysis. According to the current findings, Micali's nomogram can be used for treatment prediction after SWL, RIRS and PNL; however, a lower discrimination performance than the one at internal validation should be acknowledged, reflecting geographical, temporal and domain limitation of external validation studies. Further prospective evaluation is required to refine and improve the nomogram findings and to validate its clinical value.

Comparison of Shock Wave Lithotripsy and Flexible Ureterorenoscopy in the Treatment of 10-20 mm Lower Pole Stone: Prospective Non-randomized Study.

The objective of the study is to clarify the efficiency, safety, and limitations of shock wave lithotripsy (SWL) and flexible ureterorenoscopy (f-URS) in the management of lower pole stones (LPS). The present study was planned prospectively in a non-randomized manner. Patients who had LPS between 10 and 20 cm in size were enrolled in the study. Patient demographic characteristics, stone-related parameters, complications, and success were noted. Patients who underwent SWL and patients who underwent f-URS were compared according to demographic characteristics, procedure-related parameters, complications, and success rate. A total of 82 patients matched the study inclusion criteria, with 44 patients treated with SWL and 38 patients treated with f-URS. The time between diagnosis and the end of the treatment was 29.2 days in the SWL group and 15.2 days in the f-URS group (p = 0.001). The success rate was 89.5% with f-URS and 72.7% with SWL (p = 0.036). Receiver operating curve analysis revealed that a stone size larger than 14 mm in the lower pole was significantly associated with SWL failure (area under the curve [AUC]: 0.711, p = 0.033), and a stone size larger than 16 mm was a predictive factor for f-URS failure. The present study found that f-URS had a significantly higher stone-free rate in the management of 10-20 mm LPS compared to SWL. For the first time, this study showed that the time between diagnosis and the end of treatment was significantly shorter with f-URS. Moreover, LPS larger than 14 mm and 16 mm were predictive factors for SWL and f-URS failure, respectively.

Predictors of stone-free rate after a single-session extracorporeal shockwave lithotripsy for a single kidney stone measuring 10 to 20 mm: A private center experience.

Despite the continuous update of guidelines for the management of kidney stones, the ability to predict a successful response to extracorporeal shockwave lithotripsy (SWL) remains a topic of research. This is due to the need to refine the decision making in the context of technological advancements and current pandemics. This study aimed to determine the predictors of stone-free rate (SFR) after single-session SWL in adult patients with a single kidney stone 10 to 20 mm in diameter. A retrospective review of the records of patients with a single kidney stone 10 to 20 mm in diameter was performed at a private SWL center from December 2019 to February 2021. Univariate and multivariate analyses were performed for stone- and patient-related factors, using the Student t and Mann-Whitney U tests for the quantitative variables and the Fisher exact and Pearson correlation tests for the qualitative variables. A total of 138 patients were eligible for this study, including 92 men and 46 women. The mean age was 38.6 ± 12.4 years, and the mean body mass index (BMI) was 25.9 ± 3.4 kg/m2. Four weeks after SWL, 120 patients (87%) were free of stones, and 18 (13%) needed further treatment. Univariate analyses showed that SFR was negatively correlated with increased BMI (p = 0.0001), maximum stone length (p = 0.0001), transverse diameter of the stone (p = 0.0001), number of shocks per session (p = 0.052), and Hounsfield unit (HU) (p = 0.0001). Multivariate analysis revealed that HU (p = 0.009), maximum stone length (p = 0.01), BMI (p = 0.000), and presence of double-J stent (p = 0.034) were independent risk factors for failure of single-session SWL in the treatment of kidney stones 10 to 20 mm in diameter. The estimated average cost per case was USD 450.5. Increased HU, maximum stone length, BMI, and presence of double-J stents were independent risk factors for low SFR after single-session SWL for a kidney stone 10 to 20 mm in diameter. The cost of SWL remains an advantage in the private sector.

Efficacy of ultrasound monitoring during extracorporeal shock wave lithotripsy: A multi-institutional propensity score-matched study.

To evaluate the efficacy of ultrasound-assisted monitoring during shock wave lithotripsy for kidney and proximal ureteral calculi. We retrospectively reviewed 535 patients who initially underwent shock wave lithotripsy for renal or proximal ureteral calculi between January 2012 and December 2021. The patients were divided into the X-ray group (n = 294) and ultrasound plus X-ray group (n = 241) based on the methods of targeting and monitoring calculi during shock wave lithotripsy. Because of differences in patient backgrounds, 1:1 propensity score-based matching was performed. The primary endpoint was the stone-free rate. In the final 1:1 matched cohort, 192 kidney stone cases and 162 proximal ureteral stone cases were analyzed. For patients with kidney calculi, the stone-free rate of the ultrasound plus X-ray group was significantly higher than that of the X-ray group (66.7% vs. 47.9%; P = 0.013). In the multivariate analysis, a large stone area (odds ratio 2.37), lower caliceal stones (odds ratio 3.37), and X-ray monitoring alone (odds ratio 0.49) were independently associated with shock wave lithotripsy failure. For patients with proximal ureteral stones, there was no significant difference in the stone-free rate between the ultrasound plus X-ray group and X-ray group (71.6% and 58.0%, respectively; P = 0.100). During the multivariate analysis, high computed tomography attenuation (odds ratio 2.31) and large stone area (odds ratio 2.18) were independent factors associated with residual stones after shock wave lithotripsy. Ultrasound-assisted monitoring may contribute to a higher stone-free rate for patients with kidney calculi, but not for those with proximal ureteral calculi.

Determining whether previous SWL for ureteric stones influences the results of ureteroscopy as the second-line treatment: A clinical study.

The purpose of the study was to establish whether shock wave lithotripsy (SWL) is a potential harmful first-line treatment for ureteric stones where ureteroscopy (URS) is necessary as a second-line treatment. Medical records of patients with ureteric stones who underwent either URS as the only therapy applied or SWL followed by URS over two years were retrospectively evaluated. In total, 158 patients were included: 79 patients in Group A (no SWL) and 79 in Group B (prior SWL before URS). There was no difference in major complications, Group A had higher stone-free rates, Group B had higher rates of ureteral edema and similar intraoperative ureteral lesions. In conclusion, the failure of SWL for lumbar or pelvic ureteral lithiasis does not appear to have a negative effect on the rate of intraoperative complications or the success rate of semi-rigid retrograde URS for this category of calculi, with the same safety profile as first-line endourological intervention.

Comparison of ureteroscopy (URS) complementary treatment after extracorporeal shock wave lithotripsy failure with primary URS lithotripsy with holmium laser treatment for proximal ureteral stones larger than10mm

BackgroundTo compare ureteroscopy (URS) complementary treatment following extracorporeal shock wave lithotripsy (SWL) failure with primary URS lithotripsy for proximal ureteral stones > 10 mm, and try to find out acceptable number of SWL sessions followed by safe URS.MethodsThis was a retrospective study following approval from Medical Ethics Committee of People's Hospital of Chongqing Banan District. Patients (n = 340) who received URS in our hospital for stones > 10 mm from Jan 2015 to June 2020 were divided into two groups according to their previous SWL history. Group 1 consisted of 160 patients that underwent unsuccessful SWL before URS. Group 2 encompassed 180 patients without SWL before URS. Patient’s operative outcomes were compared. A logistic regression and receiver operator characteristics (ROC) were used to identify the acceptable number of SWL sessions prior to URS, regarding the intra-operative complications of URS.ResultsThe group 1 required more surgery time (41.38 ± 11.39 min vs. 36.43 ± 13.36 min, p = 0.01). At the same time, more intra-operative (68.1% VS 22.8%, p < 0.05) and post-operative (35% VS 18.0%, p = 0.001) complications occurred in group 1. Need more hospital stay in group 1 (2.7 ± 1.2 days vs 1.6 ± 1.1 days, p < 0.05). More patients in group 1 need further URS (16.3% VS 8.9%, p = 0.029). After second URS, the SFR of URS in two groups was insignificant differences (82.5% VS 88.9%, p > 0.05). The median (25–75%) of SWL sessions before URS was 2 (1–3) in group 1. According to the results of logistic regression analysis, patients suffered more SWL failure have an increased risk of complications during URS (OR = 1.995, 95% CI: 1.636–2.434). ROC showed that the optimal number of SWL session followed by URS were 0.5, with a sensitivity of 67.7% and specificity of 71.5%. Intra-operative complication rates of URS treatment were higher in patients who suffered > 1 SWL failure (72.6% vs 57.4%, p = 0.047).ConclusionThere was no acceptable number of SWL sessions that could be followed by URS with fewer intra-operative complications. Patients who underwent previous SWL were likely to suffer more intra-operative complications, the average operating time, hospitalization time, and needing further treatment, during URS treatment for proximal ureteral stones larger than 10 mm.

Predictive factors of extracorporeal shock wave lithotripsy failure in the treatment of patients with ureterolithiasis

Efficacy of different approaches to the treatment in patients with ureteral calculi and predictive factors for the success are the objects of contemporary studies. However, only few on them studied the duration factor of typical ureterolithiasis symptoms and changes of the ureter wall as predictive factors of extracorporeal shock wave lithotripsy (ESWL) failure in patients with ureteral stones. The aim of the study was to determine the peculiarities of histological changes in the ureter wall as a result of calculus presence and to evaluate the predictive factors of ESWL failure in patients with ureterolithiasis. Materials and methods. An analysis of the treatment by ESWL in 662 patients with ureterolithiasis was performed. The patients were divided into two groups: Group 1, n = 629 (95.0 %) individuals with effective ESWL and Group 2, n = 33 (5.0 %) patients with ESWL failure when calculi were not eliminated. Stones were found in 378 (57.0 %) patients in the upper third of the ureter, in 50 (7.6 %) – in the middle and in 234 (35.4 %) – in the lower third. For determining the predictors of ESWL failure, the Spearman’s Rank Correlation Coefficient was used. Results. The overall ESWL efficacy in our study was 95.0 %. The strong inverse correlation was found between the ESWL success and duration of symptoms (r = -0.92) and stone size (r = -0.68). Stone localization in the ureter did not influence the ESWL outcomes (r = 0.27). Conclusions. Increasing of the period from the manifestation of primary clinical symptoms to the implementation of ESWL reduces the treatment efficacy. Patients with ureteral stones more than 15 mm have lower stone-free rates after ESWL.

Does previous unsuccessful shockwave lithotripsy influence the outcomes of ureteroscopy?-a systematic review and meta-analysis.

BackgroundTo determine whether previous unsuccessful shockwave lithotripsy (SWL) influence the outcomes of ureteroscopy (URS).MethodsAn exhaustive search of PubMed, EMBASE, Web of Science and Cochrane Library were conducted to find eligible studies before October 2020. Result variables consisting stone-free rate (SFR), operation time and postoperative modified Clavien grade I-IV complications were pooled utilizing RevMan 5.3.ResultsSeven studies with 2413 individuals were included. Pooled results revealed that the salvage URS after failed SWL was similar to URS performed primarily regarding SFR [odds ratio (OR) =0.84, P=0.15] and operation time [weighted mean difference (WMD) =6.79, P=0.19]. Additionally, no statistically significant differences concerning fever (OR: 1.36; P=0.32), hematuria (OR: 0.81; P=0.75), urinary tract infection (OR: 1.57; P=0.28), renal colic (OR: 1.94; P=0.50), ureteral perforation (OR: 1.44; P=0.46), ureteral avulsion (OR: 1.21; P=0.83), stone migration (OR: 0.92; P=0.86) and sepsis (OR: 0.46; P=0.38) were observed between salvage URS and primary URS group.DiscussionThe success rates and complications of URS were not impacted by previous unsuccessful SWL. The salvage URS is equally effective and safe to primary URS.

Percutaneous Nephrolithotomy in Paediatric Population: A Single Center Experience.

Management of paediatric stone disease is challenging as they are considered high risk group. Percutaneous nephrolithotomy is minimally invasive procedure with definite advantages in terms of higher stone clearance in single session and no long term effect in renal function. Retrospective study was done including all patients upto the age of 18 years who underwent Percutaneous nephrolithotomy from January 2010 to December 2018 in our center after taking approval from ethical committee. Data was collected regarding gender, operative side, operative time duration, hospital stay, post-operative decrease in hemoglobin, stone size, Guy's stone score and early post-operative complications with Clavien-Dindo grade. Percutaneous nephrolithotomy was done in 48 renal units in 44 patients. 28 patients were boys and 16 were girls with mean age of 10.91 ± 5.22 years and mean stone size 17.16 ± 6.43 mm. 91.6% of cases had Guy's stone score of 1 and 2. Standard percutaneous nephrolithotomy was done in 21 renal units, mini percutaneous nephrolithotomy in 24 renal units and supermini percutaneous nephrolithotomy was done in three renal units with total stone free rate of 93.4%. Three patients required extracorporeal shockwave lithotripsy for significant residual stone. Average post-operative hemoglobin drop was 1.2 gm%. Overall complications rate was 18.1% with 4.5% of complications being grade 1 and 2 whereas 13.6% were Grade 3. Percutaneous nephrolithotomy is safe and feasible in paediatric patients with large stone burden, complex anatomy or shock-wave lithotripsy failure with acceptable complication and stone free rate.

Colour-coded density-gradients stone mapping: A novel reporting system for stone density on non-contrast computed tomography and its clinical applications

ABSTRACT Objective To presents a novel clinically oriented system to report stone attenuation on non-contrast computed tomography (NCCT) using colour-coded density-gradients stone mapping and its clinical applications. Patients and methods This study was performed on 50 patients with 63 stones. All patients had a recent history of failed shockwave lithotripsy (SWL) or failed dissolution therapy by alkalinisation of urine for radiolucent stones. A multi-detector NCCT examination of the abdomen and pelvis was performed in all patients. The stones were isolated and displayed in ‘Volume Rendering Technique’ using four-colour encoding. Results Eight patients with failed dissolution therapy for radiolucent stones showed an outer layer of >500 Hounsfield units (HU) or a heterogeneous composition. A total of 42 patients with failed SWL had mean attenuations of <1000 HU on NCCT. Subsequent colour-coded stone mapping showed a dense core in all stones (>1000 HU) that failed to be clearly demonstrated by the mean HU alone. Conclusion The initial use of a colour-coded density-gradients stone mapping reporting system for stone density on NCCT is useful for explaining failure of SWL or failure of dissolution therapy for radiolucent stones in selected cases. Abbreviations: HU: Hounsfield units; MSD: mean stone density; NCCT: non-contrast computed tomography; PCNL: percutaneous nephrolithotomy; SWL: shockwave lithotripsy; VRT: Volume Rendering Technique

Development and validation of a prediction model for failed shockwave lithotripsy of upper urinary tract calculi using computed tomography information: the S3HoCKwave score

PurposeTo develop and validate a new clinical prediction model that accurately predicts the failure of shockwave lithotripsy (SWL) using information obtained from non-contrast-enhanced computed tomography (NCCT).MethodsThis multicentre retrospective cohort study consecutively enrolled patients diagnosed with upper urinary tract calculi by NCCT at five hospitals in Japan from January 1, 2006 to December 31, 2016. Among the candidate predictors, we selected the six most significant predictors a priori. The main outcome was SWL failure after three sessions. Model calibration was evaluated by the calibration slope and the Hosmer–Lemeshow test. Discrimination was evaluated by the receiver-operating characteristic curves and the area under the curve (AUC). A multivariable logistic regression analysis was performed; based on the estimated β coefficients, predictive scores were generated.ResultsOf 2695 patients, 2271 were included. Patients were divided into the development cohort (1666 patients) and validation cohort (605 patients) according to geographical factors. We developed a clinical prediction model with scores ranging from 0 to 49 points. We named the prediction model the S3HoCKwave score based on the initials of the predictors (sex, skin-to-stone distance, size, Hounsfield units, colic, and kidney or ureter). As a result of internal validation, the optimism-corrected AUC was 0.72. In the validation cohort, the Hosmer–Lemeshow test did not show statistical significance (P = 0.33), and the AUC was 0.71 (95% confidence interval 0.65–0.76).ConclusionsThe S3HoCKwave score is easy to understand, has a relatively high predictive value, and allows clinicians to make appropriate treatment selections.

The Predictive Role of Abdominal Fat Parameters and Stone Density on SWL Outcomes

Our aim was to detect the role of radiological abdominal fat parameters by tomography and stone density by plain X-ray on extracorporeal Shock Wave Lithotripsy (SWL) stone-free rate. The patients who had undergone SWL for a single opaque renal stone < 2 cm in diameter and proximal ureteric stone < 1 cm in diameter were collected retrospectively. The characteristics of patients and stones were recorded. The stone attitude, HU, abdominal fat parameters, paraperirenal fat area, perirenal infiltration and severity of hydronephrosis with pre-treatment Non- Contrast Computed Tomography (NCCT) and stone density with radiography were evaluated by a radiologist. Four weeks after the last SWL; all patients were evaluated by plain X-ray and categorized as Stone Free (SF) and Residual Fragment (RF) group. 51 patients with renal stones and 88 patients with proximal ureteral stones were included in the study. 24 (47%) and 63 (71%) patients were classified as SFfor renal and ureteral stones respectively. Only stone size was an independent predictor for stone-free rates after SWL for renal and proximal ureteral stones on multivariate analysis. The Receiver Operating Characteristic (ROC) curves for renal calculi revealed that creatinine level, stone size, stone attitude, Houns-Field Unit (HU) and Skin-to-Stone Distance (SSD) were the predictive factors for the SWL outcome (p< 0.05). The ROC curve for ureteral calculi demonstrated that HU, stone size and attitude were the predictive factors (p< 0.05). All abdominal fat parameters and the stone density were not related to SWL failure. A large follow-up with more patients is essential to confirm the role of radiological parameters on the outcome of SWL.

Factors predictive of shockwave lithotripsy failure for ureteral stones: why we need to hurry.

The aims of this study are to evaluate the prognostic factors of extracorporeal shockwave lithotripsy in patients with ureteric stones, and to identify which patients might directly benefit of an endoscopic treatment. We performed a prospective study from January 2013 and July 2016 on patients with single ureteric stone and undergoing extracorporeal shockwave lithotripsy (SWL). We divided patients into two groups: first group (success group) included cases resolved with SWL only, and a second group (failure group) including patients with stone not resolved by SWL and requiring an endoscopic treatment. We evaluated age, weight, height, body mass index, stone size, hydronephrosis, laterality, location, days elapsed from onset of symptoms to SWL and stone density when computed tomography was performed. In case of stone fragments >4 mm, the procedure was repeated up to a maximum of three times. SWL was considered as failed if patients had a residual stone of any size after a follow-up of 3 months or if a complication occurred. 274 patients completed follow-up and were enrolled in the study. Mean age was 53.22 years (standard deviation: 13.98). SWL overall success rate was 84.3% (231 patients successfully treated with shockwaves) and failure rate was 15.7% (43 patients underwent auxiliary endoscopic procedure). At the univariate analysis, we observed a statistically significant difference for hydronephrosis (P=0.006), time elapsed from symptoms onset (P=0.013), patients' age (P=0.06) and mean stone density (0.023). In the multivariate logistic regression, patients' age (OR: 1.517), and time elapsed from obstruction to SWL (OR: 3.005) were independent predictive factors for SWL failure. Furthermore, moderate and severe hydronephrosis seemed to be independent predictive factors for SWL failure, presenting an OR of 2.451 and 4.207 respectively. High stone density resulted to be a predictive factor for SWL failure (OR: 2.293 if density was higher than 1100 Hounsfield Units). We report a large series of patients undergone primary SWL for ureteric stones. Our data demonstrated the role of hydronephrosis, time elapsed from obstruction onset to treatment and stone density as independent predictive factors of SWL failure.

Impact of previous SWL on ureterorenoscopy outcomes and optimal timing for ureterorenoscopy after SWL failure in proximal ureteral stones.

We aimed to evaluate the impact of previous unsuccessful shock wave lithotripsy (SWL) therapy on ureterorenoscopy (URS) outcomes in proximal ureteral stones and to define whether there is any optimal timing for safe URS after SWL. The patients who underwent URS for proximal ureteral stones between the years 2015 and 2018 in eight centers were included. Patients were divided into two groups according to previous SWL history; group 1 consisted of patients without SWL before URS for the stone [SWL (-)] and group 2 consisted of patients with a previous SWL for the stone [SWL (+)]. Demographics, operation outcomes and stone characteristics were compared between these two groups. Regarding the complication and success rates, optimal timing for URS after SWL for the stone was calculated with receiver operator characteristics curve analysis. Totally 638 patients were included (group 1: 466 patients and group 2: 172 patients). The operation and hospitalization times, rate of ureteral stenting and complications were significantly higher in group 2. Stone free status was similar between the groups. Optimal timing for URS after SWL was calculated as 16.5days (AUC = 0.657, p = 0.012) with a sensitivity of 68% and specificity of 72%, regarding the complication rates. Complication rates were significantly higher in patients who were operated before 16.5days (27.7% vs 6.5%, p < 0.001). The optimal timing; 2-3weeks delay of the URS procedure after unsuccessful SWL may decrease complication rates according to our results.

Does Previous Failed Shockwave Lithotripsy Treatment Have an Influence on Retrograde Intrarenal Surgery Outcome?

Background: The prevalence of urolithiasis is nearly 20% and patients with urolithiasis constitute an essential part of the patients referred to the urology clinic. Many parameters should be considered for the management of renal stones and authors recommend extracorporeal shockwave lithotripsy (SWL), retrograde intrarenal surgery (RIRS), and percutaneous nephrolithotripsy (PNL), as treatment options. Among these techniques, SWL does not require general anesthesia, has 89% success rate for renal pelvic stones: 83% for upper caliceal stones, 84% for middle caliceal stones, and 68% for lower caliceal stones. In this study, we aimed to investigate whether the previously failed SWL treatment affects RIRS outcome. Methods: Patients who underwent RIRS for kidney stones between January 2012 and December 2017 in Diskapi Yildirim Beyazit Training and Research Hospital were reviewed retrospectively. Patients treated with primary RIRS (186 patients) were classified as Group 1. The outcomes of these patients were compared with those of 186 patients who underwent RIRS after failed SWL treatment using matched-pair analysis, and these patients were classified as Group 2. Results: The procedure success was defined as the sum of the stone-free and clinically insignificant residual fragments (CIRFs); final success rates were 90.3% and 91.9%, respectively. If we compare the final success rates, there was no statistically significant difference between both groups (P = .584). Conclusions: As a result, there is no negative effect of the previous unsuccessful SWL treatment on the RIRS success. Patients with CIRF should be followed up more carefully in terms of becoming symptomatic.

The role of super-mini percutaneous nephrolithotomy (SMP) in the treatment of symptomatic lower pole renal stones (LPSs) after the failure of shockwave lithotripsy (SWL) or retrograde intrarenal surgery (RIRS).

To assess the safety and efficacy of super-mini percutaneous nephrolithotomy (SMP) in the treatment of symptomatic lower pole renal stones (LPSs) after the failure of shockwave lithotripsy (SWL) or retrograde intrarenal surgery (RIRS), we retrospectively evaluated 44 patients with symptomatic LPSs with previously failed SWL or RIRS and consequently underwent SMP from October 2014 to March 2016. The percutaneous renal access was performed 12-14F with C-arm fluoroscopy or ultrasonographic guidance. Stone disintegration was performed using either Holmium laser or pneumatic lithotripter. Perioperative parameters along with operations were assessed in detail. A total of 44 patients (mean age 49.1 ± 13.7years) were included in the study. Stone size was 18.4 ± 6.0mm (range 9-29), operative time was 63.9 ± 32.7min (range 14-145) and hospital stay was 2.8 ± 1.2days (range 1-5). The hemoglobin drop was 12.4 ± 8.8g/L (range 0-31), and no patients required blood transfusion. Complete stone-free status was achieved in 40 (90.9%) patients. Clinically insignificant residual fragments were observed in three (6.8%) patients and only one (2.3%) patient had a 6mm residual calculus. A total of three minor complications (urinary tract infection, hemorrhage resolved by hemostatics and renal colic requiring analgesics) were observed postoperatively. For symptomatic LPSs after the failure of SWL or RIRS, SMP is a safe and efficient auxiliary option and even might be an alternative to SWL or RIRS, while further considering the stone-free rates and stone-related events.

Advanced non-contrasted computed tomography post-processing by CT-Calculometry (CT-CM) outperforms established predictors for the outcome of shock wave lithotripsy.

To evaluate the predictive value of advanced non-contrasted computed tomography (NCCT) post-processing using novel CT-calculometry (CT-CM) parameters compared to established predictors of success of shock wave lithotripsy (SWL) for urinary calculi. NCCT post-processing was retrospectively performed in 312 patients suffering from upper tract urinary calculi who were treated by SWL. Established predictors such as skin to stone distance, body mass index, stone diameter or mean stone attenuation values were assessed. Precise stone size and shape metrics, 3-D greyscale measurements and homogeneity parameters such as skewness and kurtosis, were analysed using CT-CM. Predictive values for SWL outcome were analysed using logistic regression and receiver operating characteristics (ROC) statistics. Overall success rate (stone disintegration and no re-intervention needed) of SWL was 59% (184 patients). CT-CM metrics mainly outperformed established predictors. According to ROC analyses, stone volume and surface area performed better than established stone diameter, mean 3D attenuation value was a stronger predictor than established mean attenuation value, and parameters skewness and kurtosis performed better than recently emerged variation coefficient of stone density. Moreover, prediction of SWL outcome with 80% probability to be correct would be possible in a clearly higher number of patients (up to fivefold) using CT-CM-derived parameters. Advanced NCCT post-processing by CT-CM provides novel parameters that seem to outperform established predictors of SWL response. Implementation of these parameters into clinical routine might reduce SWL failure rates.

Does Previous Open Renal Stone Surgery Affect the Outcome of Extracorporeal Shockwave Lithotripsy Treatment in Adults with Renal Stones?

To evaluate the effects of previous ipsilateral open renal stone surgery (ORSS) on outcomes of extracorporeal shockwave lithotripsy (SWL) in adults with renal stones. A total of 2097 renal units with renal stones underwent SWL treatment at our institution between March 1997 and February 2013. One thousand eight hundred thirty-nine (87.7%) of these had no history of ORSS and were categorized as group 1, and 258 (12.3%) patients having history of ipsilateral ORSS were categorized as group 2. Characteristics of patients, stone and treatment, stone-free, and complications rates were documented in detail and compared in each group. These groups were also subclassified into four subgroups according to the stone location. The stone-free rates were statistically higher in group 1 than group 2 (73.2% and 61.6%, respectively). There were no differences between groups regarding the complications and steinstrasse. The stone-free rate of SWL for stones located at lower calix has significant difference according to groups 1 and 2 (64% vs 48.4%, p = 0.001). Logistic regression analysis showed that history of ORSS increased SWL failure rate 1.39 times. Overall stone-free rates after SWL treatment was found to be significantly lower in patients with the history of ORSS than in patients without, and this finding was significantly prominent for lower calix stones. We believe that retrograde intrarenal surgery or mini- /micro-percutaneous nephrolithotripsy, despite its possible difficulties in accessing due to anatomical changes, might be a good alternative for SWL.

103 - The role of super-mini percutaneous nephrolithotomy (SMP) in the treatment of symptomatic lower pole renal stones (LPSs) after the failure of shockwave lithotripsy (SWL) or retrograde intrarenal surgery (RIRS)

103 - The role of super-mini percutaneous nephrolithotomy (SMP) in the treatment of symptomatic lower pole renal stones (LPSs) after the failure of shockwave lithotripsy (SWL) or retrograde intrarenal surgery (RIRS)

A prospective randomised double-blind placebo-controlled trial to assess the effect of diuretics on shockwave lithotripsy of calculi

ObjectiveTo assess the effect of diuretics with shockwave lithotripsy (SWL) on the treatment of renal and upper ureteric calculi. Patients and methodsAdult patients with a solitary non-obstructive radio-opaque renal or upper ureteric calculus with normal renal function were included. They were prospectively randomised to receive either SWL with placebo or SWL with diuretics (40mg parenteral furosemide) in a double-blind manner with a sample size of 48 patients in each arm. The primary outcomes were the SWL success and failure rates. The secondary outcomes were the number of shocks and sessions. ResultsComplete fragmentation was achieved in 89.6% of the patients in the furosemide arm as compared to 81.3% in the placebo arm. Clearance was achieved in 77.1% of the patients in the furosemide arm as compared to 70.8% in the placebo arm. The number of shocks and the number of sessions were higher in the placebo arm. These differences were not statistically significant. ConclusionThe use of diuretics along with SWL treatment of renal and upper ureteric calculi does not show a statistically significant improvement in fragmentation or clearance.