Unsuccessful Shock Wave Lithotripsy Research Articles

Predicting the Efficacy of Repeated Shockwave Lithotripsy for Treating Patients with Upper Urinary Tract Calculi Using an Artificial Neural Network Model.

To establish a prediction model for repeated shockwave lithotripsy (SWL) efficacy to help choose an appropriate treatment plan for patients with a single failed lithotripsy, reducing their treatment burden. The clinical records and imaging data of 304 patients who underwent repeat SWL for upper urinary tract calculi (UUTC) at the Urology Centre of Shiyan People's Hospital between April 2019 and April 2023 were retrospectively collected. This dataset was divided into training (N = 217; 146 males [67.3%] and 71 females [32.7%]) and validation (N = 87; 66 males [75.9%] and 21 females [24.1%]) sets. The overall predictive accuracy of the models was calculated separately for the training and validation. Receiver operating characteristic (ROC) curves were plotted, and the area under the ROC curve (AUC) was calculated. The normalized importance of each independent variable (derived from the one-way analyses) in the input layer of the artificial neural network (ANN) model for the dependent variable (success or failure in repeat SWL) in the output layer was plotted as a bar chart. This study included 304 patients, of whom 154 (50.7%) underwent successful repeat SWL. Predictive models were constructed in the training set and assessed in the validation set. Fourteen influencing factors were selected as input variables to build an ANN model: age, alcohol, body mass index, sex, hydronephrosis, hematuria, mean stone density (MSD), skin-to-stone distance (SSD), stone heterogeneity index (SHI), stone volume (SV), stone retention time, smoking, stone location, and urinary irritation symptom. The model's AUC was 0.852 (95% confidence interval (CI): 0.8-0.9), and its predictive accuracy for stone clearance in the validation group was 83.3%. The order of importance of the independent variables was MSD > SV > SSD > stone retention time > SHI. Establishing an ANN model for repeated SWL of UUTC is crucial for optimizing patient care. This model will be pivotal in providing accurate treatment plans for patients with an initial unsuccessful SWL treatment. Moreover, it can significantly enhance the success rate of subsequent SWL treatments, ultimately alleviating patients' treatment burden.

Laparoscopic transperitoneal ureterolithotomy is an effective and safe method for >15 mm impacted ureteral stones in elderly patients: single center 10-year experience.

The aim of our study is to investigate the efficacy and safety of laparoscopic ureterolithotomy operation in elderly patients with large and impacted ureteral stones. Between January 2011 and July 2021, 66 elderly patients with impacted, > 15 mm upper and middle ureteral stones underwent laparoscopic ureterolithotomy in our center. The data for all patients were evaluated retrospectively. The mean age of the patients was 65 ± 5.43 years. The mean stone size was 20.2 ± 2.5 mm. The mean operation time was 93.6 ± 13.2 minutes. Among patients, 16 (24.2%) had history of unsuccessful shock wave lithotripsy and 12 (18.1%) patients had history of ureterorenoscopy. Stone-free rate was 95.4% in all patients. Modified Clavien grade 1 complications were seen in 18 patients (27.2%), but no significant perioperative and postoperative complications were observed. Urinary extravasation lasting 5, 7 and 9 days was observed in 5 patients (7.5%) who were treated conservatively. The mean hospital stay was 3.4 ± 1.52 days. The patients were asymptomatic at the 6th week post-op follow-up, and no stones were seen on direct X-ray and abdominal ultrasonography. Intravenous urography and non-contrast tomography (NCCT) taken 3 months later did not show any obstruction or stenosis in the ureter. Laparoscopic ureterolithotomy can be considered as the first treatment option for elderly patients with impacted and large ureteral stones, thanks to its high success and acceptable complication rates.

Percutaneous nephrolithotomy in new versus those patients with previous history of Extracorporeal Shock Wave Lithotripsy on ipsilateral side.

Objectives:To appraise the effects of previous history of ineffectual extracorporeal shockwave lithotripsy (SWL) treatment on the execution and end result of percutaneous nephrolithotomy (PCNL).Methods:The study was performed from January 2012 till November 2019 at the urology department at our hospital, a tertiary healthcare center. In total, four hundred and twenty two patients were enrolled in the study. We arranged the study participants into two groups. Group-I comprised of 66 subjects who had undergone failed SWL 12 months prior to PCNL procedure, while Group-II included patients who had no history of previous SWL. Information related to study variables was registered in designated proformas and then processed in SPSS version 16 for the statistical computations.Results:On the whole, the mean age of patients was 45.25± 14.38 years. While the mean calculus size was 494.80±128.83 mm2. The complexity of stones formulated on the basis of Guy’s stone score was identical among the two groups. American Society of Anesthesiologists (ASA) class categories were almost similar among the two groups. Stone free rates of 80.30% and 81.74% (p value=0.73) were observed in Group-I and II respectively. Time to create PCNL tract and mean drop in hemoglobin were noted to be significantly higher in Group-I. Complication rates and grades were not being dissimilar among the two groups.Conclusion:Patients having prior history of unsuccessful SWL history before undertaking the PCNL procedure manifested similar stone free rates and complications rates as those observed in SWL naive cases of PCNL.

Variables measured on three-dimensional computed tomography are preferred for predicting the outcomes of shock wave lithotripsy.

Shock wave lithotripsy (SWL) is used to treat upper urinary tract stones. Recently, some volume analyzers have enabled preoperative assessment using three-dimensional computed tomography (3D-CT). We evaluated the efficacy of 3D-CT variables for predicting the outcomes of SWL. The study population included 193 patients who underwent SWL between November 2014 and August 2020. In addition to conventional two-dimensional computed tomography (2D-CT) assessments, 3D-CT assessments of targeted stones were retrospectively performed, and stone size and stone density (SD) were measured. The successful and unsuccessful treatment groups were compared and risk factors for an unsuccessful first SWL session were investigated. The predictive accuracy of variables measured on 3D-CT was evaluated by receiver operating characteristic curves and multivariate analyses. The success rate of the first SWL session was 73.1%. Stone volume, mean SD and highest SD on 3D-CT were significantly higher in the unsuccessful group than in the successful group. Stone volume showed a higher area under the curve (AUC) than the estimated volumetric stone burden and stone diameter, which were measured on 2D-CT (0.729, 0.683, and 0.672, respectively). The AUCs of the mean SD and highest SD on 3D-CT were higher than those on 2D-CT (0.699, 0.680, 0.617, and 0.627, respectively). Multivariate analyses identified stone volume (≥ 0.29ml), mean SD on 3D-CT (≥ 421 HU), and absence of hydronephrosis as independent predictive factors for unsuccessful SWL. 3D-CT variables were promising predictors of the outcomes of SWL. Preoperative 3D-CT assessment is helpful for selecting favorable patients for SWL.

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.

How safe and effective is stentless laparoscopic ureterolithotomy in elderly patients?

With the improvement of minimally invasive urology procedures, open surgical interventions are less common to treat ureteral calculus. Laparoscopic ureterolithotomy (LU) indications are large multiple and/or impacted ureteral calculus that may not be treated with shock-wave lithotripsy or ureterorenoscopy approaches. The aim of our study was to investigate the feasibility and safety of stentless LU in elderly patients. Between October 2011 and December 2019, 38 geriatric patients underwent stentless transperitoneal LU for upper/mid ureteral calculi. The transperitoneal route was applied in all patients by two surgeons. No double J stent inserted in any patient. The data of all patients reviewed retrospectively. The average age was 64.60±3.70years. The mean calculi size was 19.42±1.41mm. Ten patients had unsuccessful shock wave lithotripsy or ureterorenoscopy history. The calculi-free rate was 100%. Clavien grade 1 complications were seen in 11 (28.9%) cases. No major perioperative and postoperative complications were encountered. The average length of hospital stay was 3.24±1.53days. The significant advances in medical technology and healthcare, lead a rising number of geriatric patients to take benefit of even complicated surgery. Although laparoscopy and its safety in the geriatric population pursues a challenge and the assessment of this procedure is hence obligatory, we think that stentless LU is safe, economical and less uncomfortable for elderly patients.

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.

Laparoscopic surgery for upper ureteral calculi in geriatric patients: 5 years experience

Objective We have reviewed the success of laparoscopic calculi surgeries in geriatric patients. Methods A retrospective analysis was performed on the laparoscopic ureterolithotomy surgeries performed at our central between January 2014 and January 2019 to treat upper ureteral calculi in geriatric patients. Among the patients who underwent these surgeries, we evaluated data on 24 cases whose records could be fully retrieved. Results The age interval of the patients was 60–73 years, and the mean age was 63 ± 3.43 years. The size of the calculi was 19–24 mm, and mean size was 20.2 ± 2.5 mm. Because stone disease was present previously, 5 of these patients underwent endoscopic intervention, whereas two underwent open surgery. Sixteen of these patients had a history of unsuccessful shock wave lithotripsy (SWL) or ureterorenoscopy. The calculi-free rate was 100%. According to the modified Clavien classification, no major perioperative and postoperative complications were observed. The duration of hospital stay was 1–3 days, and the mean duration of stay was 1.6 ± 0.9 days. Conclusion We believe that owing to the high success and low complication rates, laparoscopic ureterolithotomy can be the first option of treatment for geriatric patients with impacted large calculi, with a history of unsuccessful SWL or ureterorenoscopy (semirigid, flexible).

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.

Retrograde intrarenal surgery for renal stones - Part 2.

Retrograde intrarenal surgery (RIRS) has become an effective and safe treatment modality in the management of urinary system stone disease. Recent developments and innovations in the flexible ureterorenoscope and auxiliary equipment have made this procedure easier and more effective with increased success rates. RIRS can be used as a primary treatment in patients with renal stones smaller than 2 cm, prior unsuccessful shock wave lithotripsy, infundibular stenosis, renoureteral malformation, skeletal-muscular deformity, bleeding diathesis and obese patients. In the second part of this detailed review for RIRS, effect of stone composition on success rate, preoperative assessment of stone-free rate, the cost of this modality, education for RIRS, fluoroscopy use, the current role of RIRS in the treatment of various urolithiasis types and special conditions, and combined treatment methods are discussed with up-to-date literature.

Retrograde intrarenal surgery for renal stones - Part 1.

The main aim in the treatment of renal stones is to clearance of the stones completely with the least morbidity. Parallel to the improvements in technology during recent years, new flexible ureterorenoscopes and effective lithotripters such as holmium laser have been developed, thus retrograde intrarenal surgery (RIRS) has become an efficient and safe option in the management of urinary system stone disease with a gradually increasing popularity. Therewithal, innovations in auxiliary equipment such as guide-wires, ureteral access sheath and stone baskets have made this procedure more effective. With this modality, nowadays, the vast majority of renal stones can be treated successfully without need of open surgery or percutaneous nephrolithotomy. RIRS can be used as a primary treatment in patients with renal stones smaller than 2 cm, in cases with prior unsuccessful shock wave lithotripsy (SWL), infundibular stenosis, renoureteral malformation, musculoskeletal deformity, bleeding diathesis as well as obese patients. The efficiency of this procedure has been also proved in pediatric patients. In the first part of this detailed review for RIRS, history, indications and contraindications, preoperative preparation, antibiotic prophylaxis, anesthesia, surgical technique related to flexible ureteroscopes and auxiliary equipment being used, postoperative care and complications of this operation are discussed with up-to-date literature.

Ureteroscopy in proximal ureteral stones after shock wave lithotripsy failure: Is it safe and efficient or dangerous?

We assessed the effectiveness of ureteroscopy (URS) in proximal ureteral stones performed after shock wave lithotripsy (SWL) failure, and determined outcomes in terms of success rate, complications, and operation time. We analyzed data of patients with previous unsuccessful SWL (Group I) and the ones that did not have SWL or URS before (Group II) for proximal ureteral stones between December 2007 and August 2014. Group I included 346 patients who underwent complementary URS and Group II 209 patients who underwent primary URS. Success rates, operation time and complications were compared between groups. Success rates of complementary and primary URS were 78.9% and 80.9%, respectively. The difference in success rates was not statistically significant between groups (p = 0.57). The complication rates of complementary URS was 12.1%, and 9.5% in primary URS (p = 0.49). No statistically significant differences were noted in terms of gender, age, stone size and side, or lithotripter type between groups. The mean operation time and need for balloon dilatation were higher in complementary URS group compared to the primary URS group, and the difference was statistically significant (p < 0.05). Complementary URS may be used safely after SWL failure in proximal ureteral stones. Its success rate and morbidities are similar to primary URS, except for longer operation time and an increased need for balloon dilatation.

Milk of calcium stones: radiological signs and management outcome.

Milk of calcium (MOC) is a rare type of stone that was first described in 1940 by Ludin and Howald who reported MOC in renal cysts. Milk of calcium is a viscous colloidal suspension of calcium salts. Stasis, obstruction and infection are important predisposing factors. Due to a layering effect, characteristic radiological signs especially in CT can help in diagnosis to avoid unsuccessful shock wave lithotripsy. This is the largest reported case series, in which radiological signs by CT scan to predict renal MOC stones, clinical picture and management outcome are described in detail. Cases with suspected renal milk of calcium stones were studied over 7 years (2008-2015). All cases were diagnosed preoperatively by non-contrast CT. Urine cultures were performed in all patients preoperatively. Intra-operative and postoperative findings were reported. Stones retrieved were sent for chemical analysis using an infrared method. Seven cases of milk of calcium renal stones were included in this study. These stones were faint radio-opaque in two cases and radiolucent in five cases. All cases were diagnosed preoperatively with non-contrast CT. Their Hounsfield units (HU) ranged from 114 to 612. All stones were located in a dependent position (gravitational effect) in the posterior aspect of dilated calyces. Five cases exhibited the typical fluid level and two cases demonstrated semilunar (half moon) pattern in the anterior surface of the stones. All cases underwent PCNL with suction and retrieval of soft stones without the need for disintegration. When stones demonstrate a low Hounsfield unit, are arranged in dependent positions within dilated calyces and exhibit fluid level or semilunar pattern on non-contrast CT, milk of calcium stones should be considered. PCNL is an effective modality for management of renal milk of calcium stones.

Previous shock-wave lithotripsy treatment does not impact the outcomes of flexible ureterorenoscopy.

Shock-wave lithotripsy (SWL) is the first-line treatment for the active removal of small and medium-sized kidney stones. Flexible ureterorenoscopy (fURS) is recommended after failed SWL treatment. The aim of this retrospective analysis is to evaluate whether prior unsuccessful SWL treatments affect the outcomes of fURS. Data from 206 patients who underwent fURS for the treatment of renal stones between September 2009 and January 2011 were collected, and the patients were divided into two groups according to their previous SWL treatment. The patient demographics, stone characteristics, operation and fluoroscopy times, stone-free rates and complications were compared. Of the patients, 114 (55.3%) did not undergo SWL prior to fURS (Group 1), whereas 92 (44.6%) completed a minimum of 3 sessions of SWL and waited at least 2 weeks before the fURS operation (Group 2). Although the mean stone number was higher in Group 2, this difference was not significant (p=0.06). The mean operation (p=0.12) and fluoroscopy times (p=0.69) were similar between the groups. The mean operation time per mm(2) stone and fluoroscopy time per mm(2) stone were not significantly different (p=0.64 and p=0.76, respectively). The length of the hospitalization and the overall complication rates were similar. After the third postoperative month, the stone-free rates were not different between the groups (82.5% and 86.9%, respectively, p=0.38). The stone-free and complication rates of fURS were not affected by previous SWL therapy.

Robotic Partial Nephrectomy for Caliceal Diverticulum: A Single-Center Case Series

The aim of this study is to examine the role of robotic partial nephrectomy (RPN) in the management of caliceal diverticula by assessing our single-center outcomes. Between July 2007 and July 2013, 7 of 670 patients underwent RPN procedures as a reason of caliceal diverticula. The indications for RPN in all cases were recurrent urinary tract infection and pain attributed to the diverticulum in addition to failed management by endourologic or extracorporeal shockwave lithotripsy (SWL) treatments. One patient with a calcified diverticulum and another with an unsuccessful SWL treatment underwent RPN without further endourologic intervention. The other five patients had a history of unsuccessful percutaneous nephrolithotomy (one case), ureteroscopy (URS) (two cases), and a combination of SWL+URS (two cases). No intraoperative or postoperative complications were observed. No patient was readmitted postoperatively. Unique features of the robotic platform facilitate the excision of diverticulum and subsequent kidney reconstruction for this benign, but complex pathology.

Role of Ultrasonography in Percutaneous Renal Access in Patients With Renal Anatomic Abnormalities

To present our experience regarding the feasibility, safety, and efficacy of ultrasound (US)-guided percutaneous nephrolithotomy in anatomically abnormal kidneys. We performed US-guided percutaneous nephrolithotomy in 15 patients with anatomically abnormal kidneys and renal calculi. Of the 15 patients, 5 had horseshoe kidneys, 5 had rotation anomalies, 2 had kyphoscoliosis, and 3 had scoliosis. The stone size, number of access tracts, operative time, hospitalization duration, rate of stone clearance, and complication rate were recorded. Percutaneous access was achieved with US guidance in the operating room by the urologist. Successful renal access was obtained by the surgeon using US guidance in all patients, and a single access was obtained in all cases. Of the 15 patients, 8 were females, and 7 were males; 8 patients had solitary stones, and 7 had multiple calculi. The renal calculi were on the right in 7 patients and on the left in 8. Three patients had previously undergone unsuccessful shock wave lithotripsy. Complete stone clearance was achieved in 13 patients. The mean operative time was 54.2 minutes. No patient required a blood transfusion because of bleeding. Urinary tract infections occurred in 2 patients, who were treated with antibiotics. A double-J catheter was not inserted in any patient; however, a ureteral catheter was used in 3 patients for 1 day. None of the patients had any major complications during the postoperative period. The stone-free rate was 87%, and 2 patients had clinically insignificant residual fragments. Our results have demonstrated that US-guided percutaneous nephrolithotomy can be performed feasibly, safely, and effectively in anatomically abnormal kidneys.

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 &lt; 10 mm and group 2, stone size &gt; 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 &lt; 0.001), and between stone size and session number (r = 0.609, P &lt; 0.001). The correlation between hydronephrotic grade, SW and session numbers was also significant (r = 0.472, P &lt; 0.001 and r = 0.441, P &lt; 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

Should Percutaneous Nephrolithotripsy Be Considered the Primary Therapy for Lower Pole Stones?

The efficacy of percutaneous nephrolithotripsy (PCNL) as a primary therapy for the treatment of lower pole caliceal lithiasis was determined. We reviewed 144 consecutive files of patients, over a period of 10 years, with noncomplicated lower pole calculi, who underwent PCNL after a single unsuccessful session of extracorporeal shockwave lithotripsy (SWL). The stone-free rate for stones less than 10 mm was 95%. A 97% rate was accomplished for stones between 11 and 20 mm and a 98% rate for stones larger than 20 mm. PCNL achieved a mean overall stone-free rate of 96.7% after a 3-month follow-up, regardless of stone size. PCNL outclasses SWL, when stratified by stone burden and lower pole location. No significant postoperative complications were encountered. PCNL is a safe and effective procedure for the management of lower pole caliceal calculi after a single unsuccessful SWL session. This procedure should be considered the primary method for the treatment of lower pole stones.

Medical Expulsive Therapy as an Adjunct to Improve Shockwave Lithotripsy Outcomes: A Systematic Review and Meta-Analysis

Modern shockwave lithotripsy (SWL) is associated with inferior results compared with the original Dornier HM3. To enhance SWL outcomes, improved patient selection based on radiographic features and modulation of shockwave delivery rate have been used. A growing body of evidence demonstrates the positive effect of medical expulsive therapy (MET) to improve spontaneous passage of urinary calculi. The purpose of this review is to tabulate the current available data that examine the addition of MET to SWL to enhance outcomes. MEDLINE was searched with a strategy developed in conjunction with a medical librarian. Trials were included if patients were randomized to receive either a medical expulsive agent or placebo or standard therapy after SWL. Study quality was assessed according to the Cochrane Renal Group criteria. The data were analyzed using RevMan meta-analysis software. Subgroup analysis was performed with respect to MET agent used, stone size, and duration of follow-up. Four randomized trials were identified. MET agents varied, with two trials using tamsulosin, one using nifedipine, and a single trial using Phyllanthus niruri extract. Two trials included patients with renal calculi, one had patients with ureteral calculi, and the fourth included patients with both ureteral and renal calculi. The pool results of the four trials included 212 patients who received MET and 206 who received placebo. The absolute risk difference of a successful outcome after SWL with the addition of MET was significantly superior to control at 17% (95% confidence interval [CI] 9%-24%); means six patients need to be treated with MET to prevent a single unsuccessful SWL of six (95% CI 4-11). The effect of MET post-SWL was even more pronounced for stones larger than 10 mm with an absolute risk difference of 26% (95% CI, 9%-43%). MET post-SWL results in a significant increase in successful treatment outcomes. Further powered, randomized studies are encouraged.