Efficacy Of Extracorporeal Shock Wave Lithotripsy Research Articles

Comparison of ureteral stone measurements for predicting the efficacy of a single session of extracorporeal shockwave lithotripsy: one-, two-, and three-dimensional computed tomography measurements.

The objective of this study was to compare the value of one-, two- and three-dimensional computed tomography (CT) measurements for predicting the efficacy of a single session of extracorporeal shock wave lithotripsy (ESWL) in patients with a single ureteral stone. A total of 165 patients were included based on the inclusion and exclusion criteria. Different models were constructed using a combination of patients' clinical data and measurements obtained by manual sketching and automated extraction software. Multivariate logistic regression was used to develop the models. Receiver operating characteristic curves were used to assess the performance of the models. There was good interobserver agreement for all measurements in different dimensions (P < 0.001). We also found that hydronephrosis, the largest diameter, the largest area, volume, and mean CT value were significantly greater in the failure group than in the success group (P < 0.01). Furthermore, all sizes and CT measurement values were found to be independent predictors for predicting efficacy after one session of ESWL (P < 0.05). In addition, the multivariate logistic analysis showed that the area under the curve (AUC) for two-dimensional and three-dimensional measurements was superior to that of one-dimensional measurement (P < 0.01). However, when size alone was included as a measurable predictor, there was no significant difference in the AUC among the one-, two-, and three-dimensional measurements (P > 0.05). In summary, after adjusting for clinical data, two- and three-dimensional measurements combining ureteral stone size and CT values were found to be the best predictors of ESWL efficacy, and software-based three-dimensional measurements should be considered to avoid interobserver variability in clinical practice.

The Role of Oral Dissolution Therapy in Increasing the Efficacy of Extracorporeal Shockwave Lithotripsy in Patients with Less Than 2 Centimeters of Renal Stones: A Systematic Review

The prevalence of renal stones is about 15% of the population. The trend is increasing with a high recurrence rate of up to 50% in 5 years, demanding a more sophisticated treatment for renal stones. ESWL is a treatment for less than 2 cm renal stones with good outcomes. Although ESWL is a technique with many advantages, many factors contribute to the outcome of ESWL with size and stones density as the most important factor. Oral dissolution therapy (ODT) has been used for decades and its effect on renal stones is beneficial to dissolve and prevent renal stones recurrence. The combination of ODT and ESWL is not yet recommended by current guidelines. The purpose of this systematic review is to summarize the latest evidence on the role of ODT in increasing the efficacy of ESWL for renal stones. The database used in this study are PubMed and Cochrane using keywords “urolithiasis”, “renal”, “shock wave”, “citrate”, and “oral dissolution therapy”. The outcome of the article sought is stone fragmentation after ESWL. 4 studies were included, and 3 compared the outcome between ESWL alone and ESWL combined with ODT. The outcome of combined therapy shows superior outcomes compared to ESWL alone with fewer sessions required for stone clearance or a higher chance for stone fragmentation. One study in children showed 100% stone clearance after ESWL with ODT, which was higher than the average success rate of ESWL in children with renal stones. Oral dissolution therapy may have a role in increasing the efficacy of extracorporeal shockwave lithotripsy for patients with less than 2 cm renal stones.

Stone Density and Skin to Stone Distance in Non-Contrast Computed Tomography as Prognostic Indicators for the Success of Extra Corporeal Shockwave Lithotripsy in Ureteral Stone Disease

Background Ureteral stones are a major health concern with a worldwide rising prevalence. Ureteral stones formed in the kidney and then descending the ureter commonly manifest themselves as renal colic. Extracorporeal shock wave lithotripsy (ESWL) and ureteroscopy are the two primary treatment modalities for the management of symptomatic ureteral calculi, Aim of the Work In this study we tried to assess the prognostic value of patient and stone characteristics in potential candidates for ESWL in ureteral stones. Patients and Methods We studied the records of 66 patients with upper ureteral calculi who underwent ESWL. We considered patients being stone free (SF) or when &amp;lt; 4 mm fragments were detected. Age, gender, skin to-stone distance, maximum stone length, stone Hounsfield units (HU) were explored in uni- and multivariate regression analysis. Results We found that obesity (BMI &amp;gt; 29.3), high stone density (HU) &amp;gt;935, skin to stone distance &amp;gt;10 and presence of ureteral stent were all factors impeding success of treatment. On the other hand, higher shock intensity and number of shocks per session were positive predictors of treatment success. Conclusion It was concluded that the evaluation of patient and stone characteristics pre ESWL can predict the success of treatment for ureteric stones and we recommend thorough evaluation of the parameters before treatment to determine the best treatment modality for each patient. To date there seems to be value in using these variables to aid in better selecting patients for ESWL and thus improving the efficacy of ESWL. Our study was limited by the number of centers and participants. A wider range of participants would probably achieve more efficient results. Further studies on a larger scale would be better to further validate these results.

Effectiveness of Extracorporeal Shockwave Lithotripsy in Removing Small and Large Stones

Objective: To examined the efficacy of extracorporeal shockwave lithotripsy in the removal of small and large stones. Study Design: Observational prospective study. Place and Duration of Study: Department of Urology, Liaquat University of Medical and Health Sciences, Jamshoro from 1st January 2018 to 31st January 2019. Methodology: Two hundred patients, 139 males and 61 females, who underwent extracorporeal shockwave lithotripsy for stones were enrolled. The participants were separated into two groups based on stone size group A (stones measuring between 1.5 to 2.0 cm) and group B (stones measuring between 2.0 and 2.5 cm). Patients who were pediatric or had co-morbidities were excluded. The number of extracorporeal shockwave lithotripsy sessions and the number of beams per session were determined based on the clearance of the stones, if the radiology report indicated that the stones were completely cleared or if fragments smaller than 2 mm in diameter were present. Results: In group A, only 26 patients had partial clearance while in group B only 2 patients had partial clearance. The majority of the patients in both groups did not report any complications. The most common complaint was isolated haematuria, with 9 (4.5%) patients in the one session group, 16 (8%) in the two session group, and 5 (2.5%) in the three or more session group reporting this symptom Two patients in group A had hematoma along with haematuria, one patient in group A had massive haematuria that required transfusion, and one patient in each group reported having steintrasse with haematuria. In addition, one patient in group A had an isolated hematoma. Conclusion: Extracorporeal shockwave lithotripsy is effective and first-line treatment option for small renal stones. For ureteric stones, the location of stones should be taken into account, as this can have an effect on the stone-free rate and efficacy of extracorporeal shockwave lithotripsy. Keywords: Extracorporeal shockwave lithotripsy (ESWL), Stone removal, Ureteric Stones, Haematuria

Efficacy of supine trans-abdominal pronated shock head ESWL for treatment of distal ureteric stones: A pilot study.

To evaluate the efficacy of extracorporeal shockwave lithotripsy (ESWL) in supine trans-abdominal approach for distal ureteric calculi and to determine the variables that could affect the outcome results. Between November 2019 and January 2021, 172 patients with a solitary distal ureteric calculus were treated with ESWL in supine position with a pronated shock wave head against the anterior abdominal wall. The outcome of treatment evaluated and the clinical and radiological findings, as well as stone characteristics, were reviewed and correlated with the stone-free rate (SFR). Overall SFR was 84.84% (140/165). Those with stone clearance, 83.57% (117/140) cleared after one session and 16.42% (23/140) needed more than one session. Only three factors had a significant impact on SFR, that is stone length, stone width, stone attenuation. For stone length ⩽ 9 mm SFR was 93.44% (114/122) compared to 60.46% (26/43) for stone length of 10-12 mm (p < 0.00001). There were statistically significant increased SFR for stones with attenuation of <0.0001 and for the mean stone width of 8.02 mm (p < 0.00001). Stone localisation was easy with good patient comfort. Supine trans-abdominal ESWL is a new, effective and safe form of treatment for distal ureteric calculi. The stone length, stone width along with stone attenuation were the only significant predictors of stone free status in supine position.

Efficacy of extracorporeal shockwave lithotripsy, with modified position of the machine head in the treatment of lower calyceal stones in obese patients.

Context:Extracorporeal shock wave lithotripsy (ESWL) has inferior results in the lower calyceal stones, especially in obese patients.Aims:This study aimed at evaluating of the efficacy of extracorporeal shockwave lithotripsy, with modified position of the machine head in the treatment of single lower calyceal stones in obese patients.Settings and Design:This was a prospective study (phase IV trial).Subjects and Methods:We studied the anterior rotation of the shock wave machine head in obese patients for the treatment of lower calyx stones. From February 2015 to June 2019, 105 obese patients (body mass index [BMI] ≥35) having lower calyx stones (≤20 mm) underwent ESWL at our institute. The procedure was done in a supine position, and the head of the shock-wave machine was tilted anteriorly. ESWL was considered successful if the kidney was completely cleared of stones.Statistical Analysis Used:The statistical methods used were descriptive statistics, mean, standard deviation frequency analysis, Chi-square test, unpaired t-test test, and Pearson correlations (r).Results:The mean BMI of these patients was 39.71 ± 2.8 kg/m2, the mean stone size was 17.4 ± 2.1 mm, the mean stone density was 767.1 ± 193.4 Hounsfield unit, and the mean of skin to stone distance (SSD) was 145.4 ± 4.5 mm. ESWL was successful in 86 (81.9%) patients; 13 patients (12.4%) showed complete success after the first session, while 37 (35.2%), 25 (23.8%), and 11 (10.5%) patients showed success after the second, third, and fourth sessions, respectively. ESWL failed in 19 (19.1%) cases. The success rate decreased significantly with higher stone density and SSD (P < 0.001), with negative correlations (r values) of −0.871 and −0.811, respectively.Conclusions:Anterior rotation of the head of the shock wave machine is a suitable option for the treatment of lower calyceal stones in obese patients.

The effect of stone size on the results of extracorporeal shockwave lithotripsy versus semi-rigid ureteroscopic lithotripsy in the management of upper ureteric stones

ABSTRACT Objectives To evaluate the role of stone size on the efficacy and safety of extracorporeal shockwave lithotripsy (ESWL) monotherapy vs ureteroscopy (URS) for managing upper ureteric stones. Patients and methods The study design was a randomised prospective study of a total cohort of 180 patients with upper ureteric single stones of 0.5–1.5 cm. Half of the patients were managed by ESWL monotherapy, while the other half underwent URS with stone fragmentation using an ultrasound lithotripter (URSL). The success rate, re-treatment rate, auxiliary procedure (AP) rate, efficacy quotient, and complications were compared between the two groups. Results After single URSL and ESWL procedures 70/90 (77.8%) and 35/90 (38.9%) of the stones were successfully cleared, respectively (P < 0.001). The re-treatment rate after ESWL was significantly higher than in the URSL group (38.9% vs 11.1%, P < 0.001). Requiring an AP was not significantly different following ESWL (22.2%) and URSL (24.4%) treatment. The overall stone-free rate (SFR) at 3 months was significantly superior in the URSL group (88.9% vs 77.8%); however, both procedures had excellent results with no significant difference for stones of <1 cm (95.5% vs 92.9%, P > 0.05), compared to better results following URSL for stones of >1 cm (82.6% vs 64.6%, P < 0.05). Conclusion Our present study supports that ESWL is recommended as a first-line non-invasive monotherapy for upper ureteric opaque stones of <1 cm, while URSL is recommended as a first-line treatment for stones of >1 cm. The results for URSL were superior with lower a re-treatment rate, rapid stone clearance in a very short time, and less radiation exposure. Therefore, stone size is an important factor for the final decision of the initial management of upper ureteric stones because it has a direct relation to the efficacy of ESWL, but it has no effect on the results of URSL.

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.

Efficacy of extracorporeal shockwave lithotripsy with furosemide and hydration in renal stone management: A randomised controlled trial

ABSTRACTObjective: To assess the effect of diuretics (furosemide) administered before extracorporeal shockwave lithotripsy (ESWL) followed by continuous infusion of 0.9% NaCl during the ESWL in patients with renal stones.Patients and methods: A tertiary care teaching hospital-based prospective randomised controlled trial was conducted from July 2015 to June 2017, including 714 patients who underwent ESWL. The patients were randomised in two groups: in Group-A, patients received 40 mg furosemide 30 min before each ESWL session and 1000 mL 0.9% NaCl intravenous hydration during the procedure. In Group-B, the patients only received 0.9% NaCl. All patients were followed-up every 2 weeks for 3 months with X-ray and ultrasonography of the kidney, ureter and bladder. Patients without a radio-opaque stone at follow-up were classified as successes.Results: After 2 months, the stone-free rate (SFR) was much higher in Group-A, at 77.0% vs 65.3% (P < 0.001). Further, for patients aged ≤40 years, the SFR was significantly higher in Group-A than Group-B, at 89.2% vs 71.4% (P < 0.001). The mean (SD) age of the patients was 34.4 (8.23) years. Amongst them, 441 (61.8%) were male and 273 (38.2%) were female. The mean (SD) stone size was 1.42 (0.21) cm in Group-A and 1.40 (0.20) cm in Group-B.Conclusion: We conclude that the efficacy of diuretics (furosemide) along with hydration is superior to hydration alone during ESWL for renal stone clearance.Abbreviations: BMI: body mass index; KUB: kidney, ureter and bladder; OPD: Outpatient Department; ESWL: extracorporeal shockwave lithotripsy; SFR, stone-free rate.

PD26-02 FLUOROSCOPIC TARGETING OF RENAL CALCULI DURING EXTRACORPOREAL SHOCKWAVE LITHOTRIPSY USING A MACHINE LEARNING ALGORITHM

INTRODUCTION AND OBJECTIVES:The efficacy of Extracorporeal Shockwave Lithotripsy (ESWL) is influenced by the time spent delivering focused energy to the stone. Manual targeting occurs at the start ...

The Influence of Pain on the Outcome of Extracorporeal Shockwave Lithotripsy

Introduction: The aim of this study was to determine the predictive value of pain scores on the efficacy of extracor-poreal shockwave lithotripsy (ESWL) and to identify other predictive risk factors for treatment success. Materials and Methods: A total of 476 patients who underwent ESWL (piezoelectric lithotripsy) for urolithiasis between September 2011 and December 2015 were identified. The primary end-point of this study was success rate, which was evaluated 4 months after ESWL. The secondary outcome was the occurrence of complications as a result of ESWL. Results: The average pain perception was reported at 5 on a scale from 0 to 10. The overall success rate of ESWL was found to be 43.9% and the success rate after the first ESWL was 35.1%. Univari-ate analysis showed no significant correlation between pain score and success of ESWL (p = 0.135). The level of intensity was correlated with pain scores (Pearson correlation -0.423, p < 0.001). Univariate analysis identified five predictive factors: sex, stone location, stone size, hydronephrosis and the use of tamsulosin. Multivariate logistic regression analysis showed that sex, stone location and size independently in-fluenced the success of ESWL (p = 0.045, p = 0.001 and p < 0.001). Conclusion: No correlation was found between the pain scores and efficacy of ESWL. Despite this absence, pain scores during ESWL sessions remain high and additional analgesia would improve patient satisfaction.

The efficacy of extracorporeal shockwave lithotripsy for symptomatic ureteral stones: Predictors of treatment failure without the assistance of computed tomography.

ObjectivesNon-contrast computed tomography (NCCT) is not always performed clinically if the diagnosis of ureteral calculi has been confirmed using other radiographic imaging modalities. The aim of this study was to identify predictors of successful extracorporeal shockwave lithotripsy (ESWL) without assistance of NCCT.MethodsWe retrospectively reviewed the medical records of patients with symptomatic solitary ureteral stones who underwent ESWL between November 2015 and January 2016. Abdominal plain radiography or intravenous urography were performed before ESWL for localization. The exclusion criteria were repeated sessions of ESWL for the target stone and congenital genitourinary tract anomalies. The demographic characteristics, clinical history, medical charges, or imaging features of the stones were recorded. Successful treatment was defined as no fragments detected on radiography or ultrasonography in 4 weeks. For radiolucent calculi, successful treatment was regarded as cases without hydronephrosis, symptoms, or hematuria. Patients experiencing intractable pain and undergoing subsequent auxiliary surgeries were regarded as having ESWL treatment failure.ResultsAge (odds ratio [OR], 1.042; 95% confidence interval [CI], 1.007–1.078), history of ipsilateral renal or ureteral calculi episodes (OR, 2.669; 95% CI, 1.281–5.687), stone burden (OR, 3.499; 95% CI, 1.284–9.530), and radiopaque stone (OR, 2.351; 95% CI, 1.049–5.267) were significant predictors of ESWL failure in all patients.ConclusionsFor treating symptomatic ureteral stones, those with smaller size, radiolucency, and without a history of ipsilateral renal or ureteral calculi could be considered for first-line therapy with ESWL.

Efficacy and safety of extracorporeal shock wave lithotripsy for chronic pancreatitis

Introduction: 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.Patients and methods: 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.Results: 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).Conclusion: 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.

A comparative study between extracorporeal shock wave lithotripsy and ureterorenoscopic lithotripsy in the management of upper ureteric calculus

Introduction and Objective: A stone in the ureter usually comes from the kidney. Urolithiasis is the third most common disease of the urinary tract which is surpassed only by urinary tract infections and pathologic conditions of prostate. There are some controversies on the effectiveness of extracorporeal shock wave lithotripsy (ESWL) and ureteroscopic lithotripsy (URSL) in ureteral stones. We aim to compare the efficacy of ESWL and URSL in the management of upper ureteric stones in terms of stone clearance.Materials and Methods: This prospective hospital based study included patients with upper ureteric calculus managed with URSL with DJ stenting or ESWL at Dhulikhel Hospital-Kathmandu University Hospital from August 2014 to December 2015. Stone size, stone clearance, number of sittings, complications and need of other procedure were recorded.Results: Total number of patients undergone ESWL was 49 and URSL was 48. There was no difference in male/ female ratio, age and stone diameter between two groups (P&gt;0.05). Total stone-free ratio was 85.71%(42/49) for ESWL and 81.25%(39/48) for URSL, partial fragmentation requiring shift of modality of treatment was 12.24%(6/49) for ESWL and 12.5%(6/48) for URSL, failed procedure was 2.04%(1/49) for ESWL and 6.25%(3/48%) for URSL(P= 0.577).Conclusion: ESWL is as effective as URSL in the management of upper ureteric calculus with no significant difference in age, male/female ratio, stone diameter and stone free ratio

Outcomes of extra corporeal shock wave lithotripsy in renal and ureteral calculi.

Since the introduction in early 1980s, Extracorporeal Shockwave Lithotripsy (ESWL) became the accepted first line treatment modality for renal and upper ureteric stones. It is simple, safe and effective noninvasive procedure which can be performed without anaesthesia in outpatient basis. The objective of this study was to determine the efficacy of ESWL to achieve complete stone clearance in the patients with different sizes of renal and upper ureteric stones. The aim of this study was to assess the outcome, efficacy and complications of ESWL in the treatment for renal and ureteric stones in terms of the site and the size of the stone in the patients presented at Dhulikhel Hospital Kathmandu University Hospital. In this prospective study a total of 430 (214 renal and 216 ureteric) cases of urinary stone disease in 257 male and 173 female patients treated by ESWL at Dhulikhel Hospital, Kathmandu University Teaching Hospital during time period of May 2010 to June 2012 were included. Data of patients with renal and ureteric stones were evaluated for stone site, size, and number of sessions. Data were analyzed using spss 13.0. Out of 430 cases, the overall stone free rate in after 1st session was 341 (79.3%) at one month and in three months follow up (3 sessions) it was increased up to 414 (96.3%). In 16 (3.7%) patients treatment was failed. Average size of the stone was 12.24 (SD± 3.65) mm. Stone free rate was 154 (72%) in the case of renal and 187 (86.6%) in the case of ureteric stones in first session. In three months follow up (three sessions) it was 204 (95.4%) and 210 (97.2%) respectively for renal and ureteric stones. In relation to size the stone free rate in <10 mm, 10-15 mm and > 15 mm was 97%, 97% and 90%. ESWL is the first line preferred choice for renal and upper ureteric stones which provides the maximum stone free rate in the case of stone size smaller than 1.5 cm.

Supine versus Prone Position during Extracorporeal Shockwave Lithotripsy for Treating Distal Ureteral Calculi: A Systematic Review and Meta-Analysis

Purpose: We aimed at evaluating the efficacy of extracorporeal shockwave lithotripsy (SWL) for treating distal ureteral calculi performed in supine vs. prone position. Materials and Methods: Eligible studies were identified by 2 reviewers using PubMed, Embase, and Web of Science databases. Outcomes included stone-free rate after the first and the final SWL session, the mean number of shocks per SWL session, the mean percentage of power used in the first SWL session, and the mean number of SWL sessions per patient. Results: Pooled data among the 647 included patients showed that supine SWL was associated with a significantly higher stone-free rate than prone SWL. This difference was consistent for both the first SWL session (OR 4.17; 95% CI 2.53-6.87; p < 0.00001) and the final session (OR 3.02; 95% CI 1.96-4.67; p < 0.00001). No differences in the mean number of shocks per SWL session, the mean percentage of power used in the first SWL session, and the mean number of SWL sessions per patient were observed between the positions. SWL complications were infrequent and the incidence was insufficient for further analysis. Conclusion: SWL is safe and effective for the management of distal ureteral calculi, and supine SWL is more effective than prone SWL for achieving a stone-free status.

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

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.

New indication of extracorporeal shockwave lithotripsy for upper ureteral calculi

Objective To evaluate stone retention time coefficient (RTC) times stone size value (RTC × S) as the indication of extracorporeal shockwave lithotripsy (ESWL) efficacy in the treatment of upper ureteral calculi.Methods From January 2009 to May 2011,180 consecutive patients including 109males and 71 females who underwent ESWL for a single radiopaque upper ureteral stone with the mean stone size (0.9 ± 0.2) cm and the mean stone retention time (12.6 ± 9.7) d were retrospectively analyzed.The mean patient age was 39 years (range from 21 to 65 years).The base of RTC was set as 1 and each 0.1 was added on it if the stone stayed one more week in upper ureter.Patients were classified into 2 groups by stone size.105 patients were in group ＜ 1 cm and 75 patients were in group≥ 1 cm.According to RTC × S value,79 patients were in group ＜ 1 and 101 patients were in group≥ 1.Stone-free rate between these two groups in the same grouping indication and between two matched groups in the different grouping indication were compared respectively.The chi-square test compared categorical variables between the two groups and all statistical analyses were 2-sided with P ＜ 0.05 defined as statistically significant.Results The overall stone-free rate of group ＜ 1 cm was significantly higher than that of group≥ 1 cm (81.9％ vs.68.0％,P ＜0.05).The overall stone-free rate of group RTC × S value ＜ 1 was significantly higher than that of group RTC × S value ≥1 (96.2 ％ vs.60.4％,P ＜ 0.05).Comparison between two matched groups showed that the stone-free rate of group RTC S value ＜ 1 was significantly higher than that of group ＜ 1 cm (96.2％ vs.81.9 ％,P＜0.05),but group RTC×Svalue≥1 was comparable to group≥l cm (60.4％ vs.68.0％,P ＞ 0.05).26 patients with ＜ 1 cm stones were enrolled in group ≥ 1 for long stone retention time and larger RTC × S value.The overall stone-free rate of them was 38.5％ (10/26) which was significantly lower than that of group≥ 1 cm (P ＜ 0.05).Conclusions The stone retention time is an important factor in efficacy of ESWL for upper ureteral calculi.Use RTC × S as a new indication of ESWL,not only the stone size but stone retention time is taken into account as well.ESWL is highly efficacious in patients with RTC × S values ＜ 1. Key words: Shock wave lithotripsy; Indication; Ureteral calculi

Original Paper Double J stent reduces the efficacy of extracorporeal shock wave lithotripsy in the treatment of lumbar ureteral stones

IntroductionWe evaluated the effect of the presence of a double J stent on the efficacy of extracorporeal shock wave lithotripsy (ESWL) in the treatment of lumbar ureteral stones.Material and methodsBetween January 2007 and February 2012, we performed a retrospective cohort study. Forty–four patients were treated by ESWL for lumbar ureteral stones and included into two groups for the analysis: group 1, non–stented (n = 27) and group 2, stented patients (n = 17). Treatment efficacy was evaluated by abdominal X–ray or CT–scan at 1 month. Stone–free patients and those with a residual stone ≤4 mm were considered to be cured.ResultsMean stone size and density in groups 1 and 2 were 8.2mm/831HU, and 9.7 mm/986HU respectively. Both groups were comparable for age, BMI, stone size and density, number, and power of ESWL shots given. The success rates in groups 1 and 2 where 81.5% and 47.1%, respectively (p = 0.017). There was no difference between the groups for stones measuring 8 mm or less (p = 0.574). For stones >8 mm, the success rates were respectively 76% and 22.2% for groups 1 and 2 (p = 0.030). Logistic regression analysis revealed a higher failure rate when a double J stent was associated with a stone >8 mm (p = 0.033).ConclusionsThe presence of a double J stent affects the efficacy of ESWL in the treatment of lumbar ureteral stones. This effect is significant for stones >8 mm. Ureteroscopy should be considered as the first–line treatment in such patients.

Predictive Value of Attenuation Coefficients Measured as Hounsfield Units on Noncontrast Computed Tomography During Flexible Ureteroscopy with Holmium Laser Lithotripsy: A Single-Center Experience

To assess the utility of attenuation coefficients as predictors of surgical outcome after a single flexible ureteroscopy (URS) with holmium laser lithotripsy. Many reports indicate that the efficacy of extracorporeal shockwave lithotripsy (SWL) can be predicted by the target's radiofrequency attenuation, measured as Hounsfield units (HUs) on noncontrast CT (NCCT). Studies of flexible URS, however, have not assessed the predictive value of attenuation coefficients on NCCT. Patients with renal stones who were treated by flexible URS with holmium laser lithotripsy between December 2009 and October 2011 at a single institute were retrospectively evaluated. Stone-free (SF) status was determined by kidneys-ureters-bladder (KUB) radiography at postoperative month 3. Correlations of possible predictors with SF status were analyzed using a logistic regression model. The comparison between groups with low and high HUs was examined using the Mann-Whitney U test. There were 219 eligible procedures. According to the logistic regression model, the maximum attenuation coefficient (P=0.105) and average attenuation coefficient (P=0.175) did not significantly, independently predict SF status. Fragmentation efficiency was significantly different between cases with low and high attenuation coefficients (P=0.001). In groups with less than 20.0-mm diameter stones, overall operative time (P<0.001 and P=0.001) and the time from starting fragmentation (P<0.001 and P=0.002) were significantly high in both attenuation groups. In groups with stones greater than 20.0 mm diameter, the two definitions of operative time revealed no differences between the low and high attenuation groups. The retrospective study design was the major limitation of this study. We found that both the maximum and average attenuation coefficients on NCCT are significantly related to the fragmentation efficiency. In addition, this study showed that, in patient groups with stone a burden <20.0 mm in diameter, both the maximum and average attenuation coefficients were significantly predictive of operative time.