Two-year experience with ureteral stones: extracorporeal shockwave lithotripsy v ureteroscopic manipulation

A Machine Learning Approach to Predict the Outcome of Urinary Calculi Treatment Using Shock Wave Lithotripsy: Model Development and Validation Study

Background

Shock wave lithotripsy (SWL), ureteroscopy, and percutaneous nephrolithotomy are established treatments for renal stones. Historically, SWL has been a predominant and commonly used procedure for treating upper tract renal stones smaller than 20 mm in diameter due to its noninvasive nature. However, the reported failure rate of SWL after one treatment session ranges from 30% to 89%. The failure rate can be reduced by identifying candidates likely to benefit from SWL and manage patients who are likely to fail SWL with other treatment modalities. This would enhance and optimize treatment results for SWL candidates.

Objective

We proposed to develop a machine learning model that can predict SWL outcomes to assist practitioners in the decision-making process when considering patients for stone treatment.

Methods

A data set including 58,349 SWL procedures performed during 31,569 patient visits for SWL to a single hospital between 1990 and 2016 was used to construct and validate the predictive model. The AdaBoost algorithm was applied to a data set with 17 predictive attributes related to patient demographics and stone characteristics, with success or failure as an outcome. The AdaBoost algorithm was also applied to a training data set. The generated model’s performance was compared to that of 5 other machine learning algorithms, namely C4.5 decision tree, naïve Bayes, Bayesian network, K-nearest neighbors, and multilayer perceptron.

Results

The developed model was validated with a testing data set and performed significantly better than the models generated by the other 5 predictive algorithms. The sensitivity and specificity of the model were 0.875 and 0.653, respectively, while its positive predictive value was 0.7159 and negative predictive value was 0.839. The C-statistics of the receiver operating characteristic (ROC) analysis was 0.843, which reflects an excellent test.

Conclusions

 We have developed a rigorous machine learning model to assist physicians and decision-makers to choose patients with renal stones who are most likely to have successful SWL treatment based on their demographics and stone characteristics. The proposed machine learning model can assist physicians and decision-makers in planning for SWL treatment and allow for more effective use of limited health care resources and improve patient prognoses.

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.

Efficacy and safety of various surgical treatments for proximal ureteral stone ≥10mm: A systematic review and network meta-analysis

Purpose

Various surgical options are available for large proximal ureteral stones, such as extracorporeal shock wave lithotripsy (ESWL), ureteroscopic lithotripsy (URSL), percutaneous nephrolithotomy (PCNL) and laparoscopic ureterolithotomy (LU). However, the best option remains controversial. Therefore, we conducted a network meta-analysis comparing various surgical treatments for proximal ureteral stones ≥10mm to address current research deficiencies.

Materials and methods

We searched PubMed, Ovid, Scopus (up to June 2019), as well as citation lists to identify eligible comparative studies. All clinical studies including patients comparing surgical treatments for proximal ureteral stones ≥10mm were included. A standard network meta-analysis was performed with Stata SE 14 (Stata Corp, College Station, TX, USA) software to generate comparative statistics. The quality was assessed with level of evidence according to the Oxford Centre for Evidence-based Medicine and risk of bias with the Cochrane Collaboration’s Review Manager (RevMan) 5.3 software.

Results

A total of 25 studies including 2.888 patients were included in this network meta-analysis. Network meta-analyses indicated that LU and PCNL had better stone-free rates and auxiliary procedures. PCNL could result in major complications and severe bleeding. In initial stone-free rate, final stone-free rate, and auxiliary procedures results, SUCRA ranking was: LU> PCNL> URSL> ESWL. In Clavien Dindo score ≥3 complications, SUCRA ranking was: LU> ESWL> URSL> PCNL. In fever, SUCRA ranking was: ESWL> LU> URSL> PCNL. In transfusion, SUCRA ranking was: LU> URSL> ESWL> PCNL. In Cluster analysis, LU had the highest advantages and acceptable side effects. Considering the traumatic nature of PCNL, it should not be an option over URSL. ESWL had the lowest advantages.

Conclusions

LU have the potential to be considered as the first treatment choice of proximal ureteral stone ≥10mm.

In situ Management of Large Upper Ureteric Calculus by Mini-Percutaneous Nephrolithotomy in the Era of Retrograde Intrarenal Surgery

Purpose

The aim of the study is to demonstrate the ease and success of in situ management of large upper ureteric stones with mini percutaneous nephrolithotomy (PCNL).

Methods

This was a prospective observational study conducted in the Department of Urology between January 2018 and June 2019. All patients underwent standard prone mini PCNL with 15Fr amplatz with 80 cases of fluoroscopic and 12 cases of ultrasound guided access. In three cases of tortuous ureters, wire was passed via retrograde catheter and retrieved via amplatz to straighten the ureter. Calculi fragmented with laser.

Results

A total of 77 patients were included in this study, 62 unilateral and 15 bilateral cases (92 renal units). The mean age was 45.4±13.7 years (range 17–71), male to female ratio was 61:16, the disease laterality (left: right) was 28:34. The mean stone size was 17.6±1.4 mm. Mean operative time was 22.4±1.5 min. 88% patients were discharged as day care. Complication rate was 6.5%, three patients had transient fever and two patients had distal migration of small fragments and they were extracted at the time of DJ stent removal by rigid ureteroscopy (100%).

Conclusion

We conclude that it is easy and effective to deal with large upper ureteric calculus when it is in a fixed position. In situ management of large upper ureteric calculus by mini-PCNL can be done safely and effectively as it is a fast procedure, prevents unnecessary manoeuvres, less complication rates and has good stone clearance rates.

Predicting shockwave lithotripsy outcome for urolithiasis using clinical and stone computed tomography texture analysis variables

We aimed to develop and evaluate a statistical model, which included known pre-treatment factors and new computed tomography texture analysis (CTTA) variables, for its ability to predict the likelihood of a successful outcome after extracorporeal shockwave lithotripsy (SWL) treatment for renal and ureteric stones. Up to half of patients undergoing SWL may fail treatment. Better prediction of which cases will likely succeed SWL will help patients to make an informed decision on the most effective treatment modality for their stone. 19 pre-treatment factors for SWL success, including 6 CTTA variables, were collected from 459 SWL cases at a single centre. Univariate and multivariable analyses were performed by independent statisticians to predict the probability of a stone free (both with and without residual fragments) outcome after SWL. A multivariable model had an overall accuracy of 66% on Receiver Operator Curve (ROC) analysis to predict for successful SWL outcome. The variables most frequently chosen for the model were those which represented stone size. Although previous studies have suggested SWL can be reliably predicted using pre-treatment factors and that analysis of CT stone images may improve outcome prediction, the results from this study have not produced a useful model for SWL outcome prediction.

Medical and surgical interventions for the treatment of urinary stones in children

BACKGROUND

Urolithiasis is a condition where crystalline mineral deposits (stones) form within the urinary tract. Urinary stones can be located in any part of the urinary tract. Affected children may present with abdominal pain, blood in the urine or signs of infection. Radiological evaluation is used to confirm the diagnosis, to assess the size of the stone, its location, and the degree of possible urinary obstruction.

OBJECTIVES

To assess the effects of different medical and surgical interventions in the treatment of urinary tract stones of the kidney or ureter in children.

SEARCH METHODS

We searched the Cochrane Register of Controlled Trials (CENTRAL), MEDLINE (Ovid), Embase (Ovid) as well as the World Health Organization International Clinical Trials Registry Platform Search Portal and ClinicalTrials.gov. We searched reference lists of retrieved articles and conducted an electronic search for conference abstracts for the years 2012 to 2017. The date of the last search of all electronic databases was 31 December 2017 and we applied no language restrictions.

SELECTION CRITERIA

We included all randomised controlled trials (RCTs) and quasi-RCTs looking at interventions for upper urinary tract stones in children. These included shock wave lithotripsy, percutaneous nephrolithotripsy, ureterorenoscopy, open surgery and medical expulsion therapy for upper urinary tract stones in children aged 0 to 18 years.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures according to Cochrane guidance. Two review authors independently searched and assessed studies for eligibility and conducted data extraction. 'Risk of bias' assessments were completed by three review authors independently. We used Review Manager 5 for data synthesis and analysis. We used the GRADE approach to assess the quality of evidence.

MAIN RESULTS

We included 14 studies with a total of 978 randomised participants in our review, informing eight comparisons. The studies contributing to most comparisons were at high or unclear risk of bias for most domains.Shock wave lithotripsy versus dissolution therapy for intrarenal stones: based on one study (87 participants) and consistently very low quality evidence, we are uncertain about the effects of SWL on stone-free rate (SFR), serious adverse events or complications of treatment and secondary procedures for residual fragments.Slow shock wave lithotripsy versus rapid shock wave lithotripsy for renal stones: based on one study (60 participants) and consistently very low quality evidence, we are uncertain about the effects of SWL on SFR, serious adverse events or complications of treatment and secondary procedures for residual fragments.Shock wave lithotripsy versus ureteroscopy with holmium laser or pneumatic lithotripsy for renal and distal ureteric stones: based on three studies (153 participants) and consistently very low quality evidence, we are uncertain about the effects of SWL on SFR, serious adverse events or complications of treatment and secondary procedures.Shock wave lithotripsy versus mini-percutaneous nephrolithotripsy for renal stones: based on one study (212 participants), SWL likely has a lower SFR (RR 0.88, 95% CI 0.80 to 0.97; moderate quality evidence); this corresponds to 113 fewer stone-free patients per 1000 (189 fewer to 28 fewer). SWL may reduce severe adverse events (RR 0.13, 95% CI 0.02 to 0.98; low quality evidence); this corresponds to 66 fewer serious adverse events or complications per 1000 (74 fewer to 2 fewer). Rates of secondary procedures may be higher (RR 2.50, 95% CI 1.01 to 6.20; low-quality evidence); this corresponds to 85 more secondary procedures per 1000 (1 more to 294 more).Percutaneous nephrolithotripsy versus tubeless percutaneous nephrolithotripsy for renal stones: based on one study (23 participants) and consistently very low quality evidence, we are uncertain about the effects of percutaneous nephrolithotripsy on SFR, serious adverse events or complications of treatment and secondary procedures.Percutaneous nephrolithotripsy versus tubeless mini-percutaneous nephrolithotripsy for renal stones: based on one study (70 participants), SFR are likely similar (RR 1.03, 95% CI 0.93 to 1.14; moderate-quality evidence); this corresponds to 28 more per 1,000 (66 fewer to 132 more). We did not find any data relating to serious adverse events. Based on very low quality evidence we are uncertain about secondary procedures.Alpha-blockers versus placebo with or without analgesics for distal ureteric stones: based on six studies (335 participants), alpha-blockers may increase SFR (RR 1.34, 95% CI 1.16 to 1.54; low quality evidence); this corresponds to 199 more stone-free patients per 1000 (94 more to 317 more). Based on very low quality evidence we are uncertain about serious adverse events or complications and secondary procedures.

AUTHORS' CONCLUSIONS

Based on mostly very low-quality evidence for most comparisons and outcomes, we are uncertain about the effect of nearly all medical and surgical interventions to treat stone disease in children.Common reasons why we downgraded our assessments of the quality of evidence were: study limitations (risk of bias), indirectness, and imprecision. These issues make it difficult to draw clinical inferences. It is important that affected individuals, clinicians, and policy-makers are aware of these limitations of the evidence. There is a critical need for better quality trials assessing patient-important outcomes in children with stone disease to inform future guidelines on the management of this condition.

Laparoscopic Ureterolithotomy vs Ureteroscopic Lithotripsy for Large Ureteral Stones

Background and Objectives:

The purpose of this study was to compare two methods (transperitoneal laparoscopic ureterolithotomy [TLU] and a combination of ureteroscopic lithotripsy [UL] with retrograde intrarenal surgery [RIRS]) designed for the treatment of large proximal ureteral calculi so that their associated complications and stone-free rates could be assessed.

Methods:

A total of 100 patients from three different hospitals who were diagnosed with large upper ureteral stones (≥15 mm) were treated via TLU (n = 48) or UL-RIRS (n = 52). They were treated between March 2012 and May 2014. The study compared the complications, success rate, patient characteristics, and the operation time between the two groups.

Results:

The immediate stone clearance rate after a single session was higher in the TLU group than in the UL-RIRS group (100% vs 73.1%, P = .005). However, there was no significant difference in the stone-free rates between the two groups three months after the last procedure was performed (100% vs 96.1%, P = .655). Regarding patients with a history of early-failure extracorporeal shock-wave lithotripsy, there was no significant difference in the stone-free rate between the two groups three months after the last procedure (100% vs 94.4%, P > .05). Further, overall complication rates between the groups were not statistically different (P = .261).

Conclusion:

This study demonstrates that TLU is an effective and safe procedure to treat large impacted upper ureteral stones. When compared to UL-RIRS, TLU showed equivalent efficacy and safety, though there were failed first-line treatments.

Endoscopic Management of Ureteric Stones: Our Initial Experience

Aims:

The aim of this study is to present our initial experience with intracorporeal pneumatic ureterolithotripsy highlighting the pattern of patients’ clinical presentation, techniques, and limitation of the procedure.

Materials and Methods:

This is a retrospective study of cases of ureteric stones managed over a period of 18 months in a private hospital. Data obtained include patients’ sociodemography, clinical presentation, stone burden, procedural technique, complication, and need for a secondary procedure. Data were analyzed using the Statistical Package for the Social Sciences version 21.

Results:

The total number of patients managed was 20 with an age range of 28–75 years and a mean of 48.2 ± 12.4 years. Majority of them, i.e., 11 (55%) were middle aged. Female gender was more predominant, 11 (55%). Flank pain was the most common mode of presentation. Right-sided stone occurred in 9 (45%), left sided in 7 (35%), and bilateral in 4 (20%). Stone location was in the upper ureter in 4 (16.7%), mid-ureter in 7 (29.2%), and lower ureter in 13 (54.2%). The stone size ranged from 6 to 18 mm with a mean of 9.7 ± 2.5 mm. Four patients (20%) required initial bilateral ureteric stenting before definitive procedure to allow for recovery from sepsis and/or nephropathy. All patients had double-J stenting and were discharged 2 days after the procedure. The procedure was successful in 19 (95%) with 100% stone clearance rate and complete resolution of symptom without any complication. One patient (5%) had a very hard upper ureteric stone which retropulsed into the renal pelvis requiring open nephrolithotomy.

Conclusion:

Endoscopic treatment of ureteric stone with intracorporeal pneumatic lithotripsy is a safe and effective treatment modality. It is, however, limited in the management of hard upper ureteric stone, especially those that are close to the pelviureteric junction due to the risk of retropulsion of the stone into the kidney.

Medical and surgical interventions for the treatment of urinary stones in children

BACKGROUND

Urolithiasis is a condition where crystalline mineral deposits (stones) form within the urinary tract. Urinary stones can be located in any part of the urinary tract. Affected children may present with abdominal pain, blood in the urine or signs of infection. Radiological evaluation is used to confirm the diagnosis, to assess the size of the stone, its location, and the degree of possible urinary obstruction.

OBJECTIVES

To assess the effects of different medical and surgical interventions in the treatment of urinary tract stones of the kidney or ureter in children.

SEARCH METHODS

We searched the Cochrane Register of Controlled Trials (CENTRAL), MEDLINE (Ovid), Embase (Ovid) as well as the World Health Organization International Clinical Trials Registry Platform Search Portal and ClinicalTrials.gov. We searched reference lists of retrieved articles and conducted an electronic search for conference abstracts for the years 2012 to 2017. The date of the last search of all electronic databases was 31 December 2017 and we applied no language restrictions.

SELECTION CRITERIA

We included all randomised controlled trials (RCTs) and quasi-RCTs looking at interventions for upper urinary tract stones in children. These included shock wave lithotripsy, percutaneous nephrolithotripsy, ureterorenoscopy, open surgery and medical expulsion therapy for upper urinary tract stones in children aged 0 to 18 years.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures according to Cochrane guidance. Two review authors independently searched and assessed studies for eligibility and conducted data extraction. 'Risk of bias' assessments were completed by three review authors independently. We used Review Manager 5 for data synthesis and analysis. We used the GRADE approach to assess the quality of evidence.

MAIN RESULTS

We included 14 studies with a total of 978 randomised participants in our review, informing eight comparisons. The studies contributing to most comparisons were at high or unclear risk of bias for most domains.Shock wave lithotripsy versus dissolution therapy for intrarenal stones: based on one study (87 participants) and consistently very low quality evidence, we are uncertain about the effects of SWL on stone-free rate (SFR), serious adverse events or complications of treatment and secondary procedures for residual fragments.Slow shock wave lithotripsy versus rapid shock wave lithotripsy for renal stones: based on one study (60 participants) and consistently very low quality evidence, we are uncertain about the effects of SWL on SFR, serious adverse events or complications of treatment and secondary procedures for residual fragments.Shock wave lithotripsy versus ureteroscopy with holmium laser or pneumatic lithotripsy for renal and distal ureteric stones: based on three studies (153 participants) and consistently very low quality evidence, we are uncertain about the effects of SWL on SFR, serious adverse events or complications of treatment and secondary procedures.Shock wave lithotripsy versus mini-percutaneous nephrolithotripsy for renal stones: based on one study (212 participants), SWL likely has a lower SFR (RR 0.88, 95% CI 0.80 to 0.97; moderate quality evidence); this corresponds to 113 fewer stone-free patients per 1000 (189 fewer to 28 fewer). SWL may reduce severe adverse events (RR 0.13, 95% CI 0.02 to 0.98; low quality evidence); this corresponds to 66 fewer serious adverse events or complications per 1000 (74 fewer to 2 fewer). Rates of secondary procedures may be higher (RR 2.50, 95% CI 1.01 to 6.20; low-quality evidence); this corresponds to 85 more secondary procedures per 1000 (1 more to 294 more).Percutaneous nephrolithotripsy versus tubeless percutaneous nephrolithotripsy for renal stones: based on one study (23 participants) and consistently very low quality evidence, we are uncertain about the effects of SWL on SFR, serious adverse events or complications of treatment and secondary procedures.Percutaneous nephrolithotripsy versus tubeless mini-percutaneous nephrolithotripsy for renal stones: based on one study (70 participants), SFR are likely similar (RR 1.03, 95% CI 0.93 to 1.14; moderate-quality evidence); this corresponds to 28 more per 1,000 (66 fewer to 132 more). We did not find any data relating to serious adverse events. Based on very low quality evidence we are uncertain about secondary procedures.Alpha-blockers versus placebo with or without analgesics for distal ureteric stones: based on six studies (335 participants), alpha-blockers may increase SFR (RR 1.34, 95% CI 1.16 to 1.54; low quality evidence); this corresponds to 199 more stone-free patients per 1000 (94 more to 317 more). Based on very low quality evidence we are uncertain about serious adverse events or complications and secondary procedures.

AUTHORS' CONCLUSIONS

Based on mostly very low-quality evidence for most comparisons and outcomes, we are uncertain about the effect of nearly all medical and surgical interventions to treat stone disease in children.Common reasons why we downgraded our assessments of the quality of evidence were: study limitations (risk of bias), indirectness, and imprecision. These issues make it difficult to draw clinical inferences. It is important that affected individuals, clinicians, and policy-makers are aware of these limitations of the evidence. There is a critical need for better quality trials assessing patient-important outcomes in children with stone disease to inform future guidelines on the management of this condition.

Factors Affecting the Outcome of Extracorporeal Shockwave Lithotripsy in Urinary Stone Treatment

Objectives

We sought to evaluate the factors affecting the outcome of extracorporeal shockwave lithotripsy (ESWL) in urinary stone treatment.

Methods

We conducted a retrospective review of 235 adult patients treated with ESWL, for radiopaque renal or ureteric stones between January 2015 and December 2016. Patient's age, sex, stone size, laterality, location, density, skin-to-stone distance (SSD), and presence of double J stent were studied as potential predictors. At the end of three months, the patients were divided into success and failure groups and the significance was determined.

Results

Of the 235 patients (188 males and 47 females) analyzed, ESWL was successful in 79.1%. Univariate analysis of both groups revealed no significant difference in patient's age and stone laterality. Statistically significant differences in gender, stone size, stone site, stone density, SSD, and patients with stents were observed. Statistically significant factors in multivariate logistic regression analysis were sex and stent. Females had three-times higher risk for ESWL failure than males (odds ratio (OR) = 3.213; 95% confidence interval (CI): 1.194-8.645; p = 0.021) and a higher failure rate when a stent was used (OR = 6.358; 95% CI: 2.228-18.143; p = 0.001).

Conclusions

This study revealed that ESWL can treat renal and ureteric stones successfully with an inverse association between outcome and predictors such as stone size and density, SSD, and stent presence. These factors can help us in improving patient selection and ensure better results at lower cost.

Laparoscopic ureterolithotomy: Experience of 60 cases from a developing world hospital

Objective

Laparoscopic ureterolithotomy, which has been quoted to have a success rate equivalent to open ureterolithotomy for uretric stones, can be performed transperitoneally and retroperitoneally. The aim of the present study is to report our experience with laparoscopic retroperitoneal ureterolithotomy, its results and advantages in the current era of minimally invasive surgery in a developing country.

Patients and Methods

It was a prospective study carried from May 2010 to December 2012. 60 patients diagnosed with upper and middle uretric calculi, with sizes more than 1 cm and with value of more than 1500 hu on CT Urography ,underwent laparoscopic retroperitoneal ureterolithotomy.

Results

All patients underwent retroperitoneal laparoscopic ureterolithotomy successfully. The mean operative time was 64.53 min. The mean blood loss was 39.83 ml. 3 patients had minor intra-operative complications which were tackled on table. Post-operative complications developed in 3 patients, all minor. There were no major complications. The removal of drain was at (2.7 days). Mean hospital stay was of 3.3 days. Patients reported to their routine activities in 1.78 weeks. During follow-up 3 months later, CT urography revealed normal ureter in all cases.

Conclusion

Laparoscopic retroperitoneal ureterolithotomy has low rate of conversion to open surgery and an acceptable overall complication rates. In selected patients with impacted, hard, large ureteral stones, which are likely to cause diffi-culty in endo-urological procedures, laparoscopic ureterolithotomy is a reason-able treatment option.

Intraureteral lidocaine for ureteral stent symptoms post-ureteroscopy: A randomized, phase 2, placebo-controlled trial

INTRODUCTION

Ureteral stent and ureteral manipulation-related pain is a significant complication for patients undergoing ureteroscopy. Herein, we report a phase 2, randomized trial to assess efficacy of direct instillation of intraureteral lidocaine in reducing postoperative pain and ureteral stent symptoms.

METHODS

We performed a randomized, double-blinded trial of patients undergoing elective ureteroscopy for ureteral calculi. Patients were randomized to direct instillation of 2% lidocaine plus bicarbonate, or to normal saline as control. The primary outcome of interest was early postoperative pain scores. Patients completed10-point visual analog pain scale at one-hour, two-hour, four-hour, 24-hours, four- and seven-day time points. Other outcome measurements collected included a medication diary and voiding questionnaire.

RESULTS

A total of 41 patients were randomized in the study. Mean flank pain scores at one hour were 2.2 (±2.9) vs.1.9 (±2.4) in the intervention and placebo group, respectively (p=0.84). There was no significant difference at any time point between the intervention and placebo groups in patient-reported pain scores. Patients reported lower dysuria scores at all time points in the lidocaine group, however, none reached statistical significance. There was no difference in complication rates or adverse effects between groups.

CONCLUSIONS

In this randomized, phase 2 study, direct instillation of lidocaine into the ureter did not appear to significantly improve pain or voiding symptoms following stented ureteroscopy.

Comparison of the efficacy and safety of URSL, RPLU, and MPCNL for treatment of large upper impacted ureteral stones: a randomized controlled trial

Background

There are three minimally invasive methods for the management of large upper impacted ureteral stones: mini-percutaneous nephrolithotomy (MPCNL), transurethral ureteroscope lithotripsy (URSL), and retroperitoneal laparoscopic ureterolithotomy (RPLU). This study aimed to compare MPCNL, URSL, and RPLU, and to evaluate which one is the best choice for large upper impacted ureteral stones.

Methods

Between January 2012 and December 2015, at the Department of Urology, Huai’an First People’s Hospital, 150 consecutively enrolled patients with a large upper impacted ureteral stone (>15 mm) were included. The patients were randomly divided (1:1:1) into the MPCNL, URSL, and RPLU groups. The primary endpoint was success of stone removal measured 1 month postoperatively and the secondary endpoints were intraoperative and postoperative parameters and complications.

Results

Fifteen patients needed auxiliary ESWL after URSL, and 3 patients after MPCNL, but none after RPLU. The stone clearance rate was 96% (48/50) in the MPCNL group and 72% (33/46) in the URSL group. In the RPLU group the stones were completely removed and the stone clearance rate was 100% (48/48) (P = 0.021 vs. URSL; P = 0.083 vs. MPCNL). Operation-related complications were similar among the three groups (all P > 0.05). Hospital stay was shorter in the URSL group compared with MPCNL (P = 0.003). Operation time was the shortest with URSL and the longest with MPCNL (all P < 0.05).

Conclusions

MPCNL and RPUL are more suitable for upper ureteral impacted stones of >15 mm. URSL could be considered if the patient is not suitable for general anesthesia, or the patient requests transurethral uretroscopic surgery.

Trial registration

This study was registered with the Chinese Clinical Trial Registry (Registration number: ChiCTR-INR-17011507; Registration date: 2017–5-22).

Minimally invasive percutaneous nephrolithotomy improves stone-free rates for impacted proximal ureteral stones: A systematic review and meta-analysis

Background

Urinary stones are common medical disorders and the treatment of impacted proximal ureteral stones (IPUS) is still a challenge for urologists. The aim of this study was to compare the efficacy and safety of minimally invasive percutaneous nephrolithotomy (MI-PCNL) and ureteroscopic lithotripsy (URL) in the treatment of IPUS via a meta-analysis.

Methods

We collected studies using PubMed, Embase, and Cochrane Library from 1978 to November 2016 and analyzed them using Stata 12.0 and RevMan 5.3. Odds ratios (ORs) and standard mean difference (SMD) were calculated for binary and continuous variables respectively, accompanied with 95% confidence intervals (CIs). All study procedures followed the PRISMA guidelines.

Results

Five prospective studies were included in our meta-analysis, with 242 MI-PCNL and 256 URL cases. MI-PCNL was associated with a longer postoperative hospital stay than URL (SMD, 3.14; 95% CI, 1.27 to 5.55). However, no significant difference was observed in operative time (SMD, -0.38; 95% CI, -3.15 to 2.38). In addition, MI-PCNL had higher initial (OR, 11.12; 95% CI, 5.56 to 22.24) and overall stone-free rates (OR, 8.70; 95% CI, 3.23 to 23.45) than URL, along with lower possibilities of surgical conversion (OR, 0.11; 95% CI, 0.03 to 0.49) and postoperative shock wave lithotripsy (OR, 0.06; 95% CI, 0.02 to 0.18). Regarding complications, no significant differences were observed between MI-PCNL and URL (OR, 1.39; 95% CI, 0.93 to 2.10), except for hematuria (OR, 4.80; 95% CI, 1.45 to 15.94).

Conclusions

MI-PCNL is optimal and should be considered as the preferred treatment method for IPUS, as it has better efficacy and a safety profile similar to that of URL. However, further high quality studies with larger sample size are required in future.

Management of upper ureteral stones exceeding 15 mm in diameter: Shock wave lithotripsy versus semirigid ureteroscopy with holmium:yttrium-aluminum-garnet laser lithotripsy

Objectives:

We conducted a retrospective study to evaluate the efficacy and outcome of shock wave lithotripsy versus semirigid ureteroscopy in the management of the proximal ureteral stones of diameter exceeding 15 mm.

Methods:

During the 2009−2014 study period, 147 patients presenting with the proximal ureteral stones exceeding 15 mm in diameter were treated. Both shock wave lithotripsy and ureteroscopy with laser lithotripsy were offered for our patients. A 6/8.9 Fr semirigid ureteroscope was used in conjunction with a holmium:yttrium–aluminum–garnet laser. The stone-free rate was assessed at 2 weeks and 3 months post-treatment. All patients were evaluated for stone-free status, operation time, hospital stay, perioperative complications, and auxiliary procedures.

Results:

Of the 147 patients who took part in this study, 66 (45%) had undergone shock wave lithotripsy and 81 (55%) underwent ureteroscopy. At the 3-month follow-up, the overall stone-free rate in the shock wave lithotripsy group was 39/66 (59%) compared to 70/81 (86.4%) in the ureteroscopic laser lithotripsy group. Ureteroscopic laser lithotripsy achieved a highly significant stone-free rate (p = 0.0002), and the mean operative time, auxiliary procedures, and postoperative complication rates were comparable between the two groups.

Conclusion:

In terms of the management of proximal ureteral stones exceeding 15 mm in diameter, ureteroscopy achieved a greater stone-free rate and is considered the first-line of management. Shock wave lithotripsy achieved lower stone-free rate, and it could be used in selected cases.

Laparoscopic Ureterolithotomy

Background and Objective:

The present study retrospectively analyzed the data of 213 patients who underwent laparoscopic ureterolithotomy.

Methods:

We retrospectively analyzed the data of 213 patients, in whom we performed conventional laparoscopic ureterolithotomy from April 2006 and January 2015 based on the diagnosis of an upper or middle ureteral stone. Patients with large ureteral stones (>15 mm) or a history of failed shock-wave lithotripsy or ureteroscopy were included in the study. Although the retroperitoneal approach was preferred for 170 patients, the transperitoneal approach was used in the remaining 43 patients.

Results:

The mean patient age was 39.3 ± 12.0 years (range, 18–73). The study population was composed of 78 (26.7%) female and 135 (63.3%) male patients. The mean stone size was 19.7 ± 2.5 mm. The mean operative time was 80.9 ± 10.9 minutes, and the mean blood loss was 63.3 ± 12.7 mL. Intraoperative insertion of a double-J catheter was performed in 76 patients. The overall stone-free rate was 99%. No major complication was observed in any patient. However, conversion to open surgery was necessary in 1 patient.

Conclusion:

With high success and low complication rates, laparoscopic ureterolithotomy is an effective and reliable method that ensures quick recovery and may be the first treatment option for patients with large, impacted ureteral stones, as well as for those with a history of failed primary treatment.

Flexible Ureteroscopy versus Retroperitoneal Laparoscopic Ureterolithotomy for the Treatment of Proximal Ureteral Stones >15 mm: A Single Surgeon Experience

OBJECTIVE

To compare safety and effectiveness of flexible ureteroscopy (F-URS) and laparoscopic retroperitoneal ureterolithotomy (L-RU) in treatment of proximal ureteral stones larger than 15 mm.

MATERIALS AND METHODS

This study included 103 patients treated with L-RU (Group I), and 80 patients treated with F-URS (Group II) due to proximal ureteral stones larger than 1.5 cm, in a single center. Patients' characteristics and procedure-related parameters including success rate, operation time, hospital stay, postoperative visual analogue scale (VAS) scores, auxiliary procedures, and complications were compared between Groups I and II.

RESULTS

It was seen that both methods were effective in the treatment of large ureteral stones; however, R-LU provided a higher stone-free rate (100 vs. 87.5%), a lower complication rate (10.6 vs. 23.7%), and a shorter operation time (65.4 vs. 75.1 min). On the other hand, patients treated with F-URS had less postoperative pain, a shorter hospital stay, a faster return to daily activities.

CONCLUSIONS

For treatment of large proximal ureteral stones, L-RU provides significantly higher success and lower retreatment rate compared with F-URS. Our results also indicate that R-LU, which has been regarded as an invasive procedure is not as invasive as it is thought to be, and it must be kept in mind that F-URS may cause complications despite its noninvasive nature.

Noncontrast computed tomography factors that predict the renal stone outcome after shock wave lithotripsy

OBJECTIVES

Extracorporeal shock wave lithotripsy (ESWL) is a popular treatment for nephrolithiasis. We took advantage of noncontrast abdominal computed tomography (NCCT) to search the possible prognostic factors including abdominal fat distribution influencing stone-free rate.

METHODS

From August 2008 to August 2010, 145 patients who had renal calculus and had undergone ESWL were retrospectively reviewed. All of them received NCCT assessment before ESWL and were followed up after 1 month for stone clearance. These patients were divided into two groups: one was the stone-free group and the other was the residual-stone group. Affecting parameters included stone size, location, stone surface area, Hounsfield unit density (HU density), skin-to-stone distance (SSD), and abdominal fat area as analyzed between these two groups.

RESULTS

Of 145 patients, 70 were stone-free and 75 had residual stone after ESWL treatment and 1-month follow-up. From univariate analysis, stone size, HU density, SSD, and stone surface area were significant predicting factors for ESWL success. On multivariate analysis, the important factors influencing ESWL outcomes were HU density and stone surface area (odds ratio 1.002 vs. 77.18, respectively; P<.05). Abdominal fat accumulation and distribution had no significant difference between these two groups.

CONCLUSION

This study revealed that stone size, HU density, SSD, and stone surface area were associated with stone-free rate after ESWL treatment. Therefore, these factors could be used to assess the feasibility of ESWL before deciding the treatment strategy. Abdominal fat distribution had no significant impact on ESWL outcome for renal stones.

Retroperitoneal laparoscopic ureterolithotomy for proximal ureteral calculi in selected patients

Objectives. To summarize our experience of retroperitoneal laparoscopic ureterolithotomy for ureteral calculi and evaluate the safety and efficiency of this procedure. Methods. We conducted a retrospective analysis of 197 patients with proximal ureteral calculi who accepted retroperitoneal laparoscopic ureterolithotomy from June 2005 to June 2014. Results. All procedures were performed successfully and the mean operating time and estimated blood loss were 87 min and 64 mL. The clearance rate was 98.5% and the rates of urine leak and ureteral stricture were 2.5% and 1.0%. Conclusions. Retroperitoneal laparoscopic ureterolithotomy is a safe and effective procedure for patients with complex stones or anatomic abnormalities, and, with experience of high volume series, it is also a reasonable choice as the primary treatment for such selected patients.

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

Introduction

We 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 methods

Between 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.

Results

Mean 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).

Conclusions

The 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.

Experience of mini-percutaneous nephrolithotomy in the treatment of large impacted proximal ureteral stones

OBJECTIVES

To evaluate the efficacy and safety of mini- percutaneous nephrolithotomy (PCNL) in the treatment of large impacted proximal ureteral stones.

METHODS

We retrospectively reviewed the outcomes of 163 patients who underwent mini-PCNL between January 2006 and August 2010. Mean age was 48.6 years and mean stone size was 18.4 mm. Hydronephrosis and/or hydroureterosis appeared in all patients. In the prone position, percutaneous access (16-Fr sheath) was established by placement of an access needle into the intended calyx under fluoroscopic guidance or combined with ultrasound guidance for complete obstruction by stones while the contrast agent cannot transit. Pneumatic or ultrasonic probes were used throughout ureterorenoscopy for lithotripsy. The ureteral stents and nephrostomy tube were placed at the end of the procedure. Mean drop in hemoglobin, operative time, success rate, hospital stay, and complications were assessed.

RESULTS

Mini-PCNL operations were performed successfully in all patients. Mean operation time was 37 min. Mean postoperative hospital stay was 3.6 days. All cases were followed up for 6-20 months. No major complications like hemorrhage, perforation or organic injury were noted during the operation or postoperatively. The stone-free rate in all patients was 95.7%. Calculus had no recurrence during the follow-up period. Hydronephrosis and hydroureterosis disappeared or were relieved.

CONCLUSIONS

Mini-PCNL is a safe and effective therapy for large impacted proximal ureteral stones.

Comparative study of outcome in treating upper ureteral impacted stones using minimally invasive percutaneous nephrolithotomy with aid of patented system or transurethral ureteroscopy

OBJECTIVE

To determine an efficient method for treating upper ureteral impacted stones, we compared the outcome of minimally invasive percutaneous nephrolithotomy with the aid of our patented system and transurethral ureteroscopy.

MATERIALS AND METHODS

A total of 182 patients with complicated impacted upper ureteral stones above the level of L4 were randomly divided into 2 groups. Group 1 included 91 patients who were treated with minimally invasive percutaneous nephrolithotomy with the aid of a patented system. Group 2 included 91 patients who were treated with ureteroscopy. The patients underwent postoperative shock wave lithotripsy, when necessary. The operative time, stone clearance rate, operative complication markers (amount of intraoperative bleeding and postoperative fever rate), and cost of treatment were compared.

RESULTS

A significantly shorter operative time, greater rate of stone clearance, lower need for postoperative shock wave lithotripsy, and lower rate of postoperative fever was found in group 1 than in group 2 (P <.05). However, the cost of treatment and amount of intraoperative bleeding were significantly greater.

CONCLUSION

We believe minimally invasive percutaneous nephrolithotomy with the aid of the patented system could be the first choice in treating complicated impacted upper ureteral stones above the level of L4.

Treatment of upper urinary tract stones with extracorporeal shock wave lithotripsy (ESWL) Sonolith vision

Background

The aim was to retrospectively assess the results of treatment of upper urinary tract stones with the Sonolith vision manufactured by EDAP, and purchased in 2004.

Methods

The subjects were 226 Japanese patients who underwent extracorporeal shock wave lithotripsy (ESWL) alone as an initial treatment and could be followed up for at least 3 months, selected from 277 candidate patients who underwent this therapy between 2004 and 2006. Treatment effect was evaluated by kidney, ureter, and bladder X-ray or renal ultrasonography at 1 and 3 months after treatment. A stone-free status or status of stone fragmentation to 4 mm or smaller was considered to indicate effective treatment.

Results

At 3 months after treatment, the stone-free rate was 69.4% and the efficacy rate was 77.4% for renal stones, while these rates were 91.5 and 93.3%, respectively for ureteral stones. Assessment of treatment effect classified by the location of stones revealed a stone-free rate of 94.6% and an efficacy rate of 94.6% for lower ureteral stones (4.0 mm or smaller, 1 subject; 4.1-10.0 mm, 31 subjects; 10.1-20.0 mm, 5 subjects: number of treatment sessions, 1 or 2 sessions [mean: 1.03 sessions]). Complications of this therapy included renal subcapsular hematoma and pyelonephritis in 1 case each.

Conclusions

ESWL with the Sonolith vision manufactured by EDAP produced a treatment effect equivalent to those achieved with other models of ESWL equipment. ESWL seems to be an effective first-line treatment also in patients who have lower ureteral stones 10 mm or larger but do not wish to undergo TUL, if measures such as suitable positioning of the patient during treatment are taken.

Value of focal applied energy quotient in treatment of ureteral lithiasis with shock waves

The treatment of ureteral lithiasis by extracorporeal shock wave lithotripsy (ESWL) is progressively being abandoned owing to advances in endoscopic lithotripsy. The purpose of this paper is to analyze the causes as to why ESWL is less effective-with a measurable parameter: focal applied energy quotient (FAEQ) that allows us to apply an improvement project in ESWL results for ureteral lithiasis. A prospective observational cohort study with 3-year follow-up and enrollment period was done with three groups of cases. In Group A, 83 cases of ureteral lithiasis were treated by endoscopic lithotripsy using Holmiun:YAG laser. In Group B, 81 cases of ureteral lithiasis were treated by ESWL using Doli-S device (EMSE 220F-XXP). In Group C, 65 cases of ureteral lithiasis were treated by ESWL using Doli-S device (EMSE 220F-XXP) (FAEQ >10). Statistical study and calculation of RR, NNT, Chi-square test, Fisher's exact test, and Student's t test were done. Efficiency quotient (EQ) and focal applied energy quotient [FAEQ = (radioscopy seconds/number of shock waves) × ESWL session J] were analyzed. From the results, the success rate of the treatment using Holmium:YAG laser lithotripsy and ESWL is found to be 94 and 48%, respectively, with a statistically significant difference (p < 0.001). Success rate of endoscopic laser lithotripsy for lumbar ureteral stones was 82% versus 57% of ESWL (p = 0.611). In Group B, FAEQ was 8.12. In Group C, success rate was 93.84% with FAEQ of 10.64%. When we compare results from endoscopic lithotripsy with Holmium:YAG laser in Group B with results from ESWL with FAEQ >10, we do not observe absolute benefit choosing one or the other. In conclusion, the application of ESWL with FAEQ >10, that is, improving radiologic focalization of the calculus and increasing the number of Joules/SW, makes possible a treatment as safe and equally efficient as Holmium:YAG laser lithotripsy in ureteral lithiasis less than 13 mm.

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

PURPOSE

Although shock wave lithotripsy is dependent on patient and stone related factors, there are few reliable algorithms predictive of its success. In this study we develop a comprehensive nomogram to predict renal and ureteral stone shock wave lithotripsy outcomes.

MATERIALS AND METHODS

During a 5-year period data from patients treated at our lithotripsy unit were reviewed. Analysis was restricted to patients with a solitary renal or ureteral calculus 20 mm or less. Demographic, stone, patient, treatment and 3-month followup data were collected from a prospective database. All patients were treated using the Philips Lithotron® lithotripter.

RESULTS

A total of 422 patients (69.7% male) were analyzed. Mean stone size was 52.3±39.3 mm2 for ureteral stones and 78.9±77.3 mm2 for renal stones, with 95 (43.6%) of the renal stones located in the lower pole. The single treatment success rates for ureteral and renal stones were 60.3% and 70.2%, respectively. On univariate analysis predictors of shock wave lithotripsy success, regardless of stone location, were age (p=0.01), body mass index (p=0.01), stone size (p<0.01), mean stone density (p<0.01) and skin to stone distance (p<0.01). By multivariate logistic regression for renal calculi, age, stone area and skin to stone distance were significant predictors with an AUC of 0.75. For ureteral calculi predictive factors included body mass index and stone size (AUC 0.70).

CONCLUSIONS

Patient and stone parameters have been identified to create a nomogram that predicts shock wave lithotripsy outcomes using the Lithotron lithotripter, which can facilitate optimal treatment based decisions and provide patients with more accurate single treatment success rates for shock wave lithotripsy tailored to patient specific situations.

Semirigid ureteroscopy in management of large proximal ureteral calculi: is there still a role in developing countries?

OBJECTIVES

To evaluate the outcome and complications of the use of semirigid ureteroscopy (URS) together with intracorporeal pneumatic lithotripsy in the management of upper ureteral calculi >10 mm in diameter.

METHODS

A total of 75 patients (41 women and 34 men), with a mean age of 48 years (range 25-60), underwent primary URS for solitary radiopaque proximal ureteral calculi 10-20 mm in diameter (average 13.1). Dilation of the intramural ureter was done in 60 cases (80% of patients), and intracorporeal lithotripsy was required in 56 (74.6%). Ureteral catheters were left for drainage in 60% of patients, 26.7% were left unstented, and only 13.3% required an indwelling stent.

RESULTS

Of the 75 stones, 60 (80%) were successfully cleared after a single endoscopic procedure. Our initial stone-free rate was 90.6% at 2 weeks after the primary endoscopic procedure and had reached 98.6% at 3 months. Antegrade URS for migrating stones was done successfully in 6 cases in a tubeless fashion, and open ureterolithotomy was required in 1 case. No major complications were encountered. The minor complications included only mild extravasation and self-limited postoperative fever and hematuria. The risk factors for URS failure included male gender, the severity of the hydronephrosis, the severity of impaction, and the occurrence of extravasation.

CONCLUSIONS

The results of our study have shown that semirigid URS is a safe and successful alternative to open ureterolithotomy in the management of large proximal ureteral calculi in the absence of flexible instruments.

Laparoscopic ureterolithotomy as a primary modality for large proximal ureteral calculi: comparison to rigid ureteroscopic pneumatic lithotripsy

OBJECTIVE

To define the role of laparoscopic ureterolithotomy (LU) as a primary modality for large proximal ureteral stones, we compared the outcomes of primary LU with those of ureterorenoscopy (URS), the currently established modality in this circumstance.

MATERIALS AND METHODS

Among 71 patients who underwent LU in our institution between February 2005 and January 2010, 32 patients with stone size over 1.5 cm who underwent LU as a primary modality without prior shockwave lithotripsy or URS and for whom LU was conducted as a separate procedure were exclusively enrolled. Based on preoperative characteristics of patients and stones, this patient group was matched with the URS group (n = 32, rigid pneumatic lithotripter) during the same period.

RESULTS

The LU group and the URS group were similar in age, gender distribution, body mass index, stone size (18.1 ± 4.2 versus 17.9 ± 3.6 mm; P = .88), and stone location. Members of the LU group required a longer operative time (118 ± 53 versus 59 ± 41 minutes; P < .001) and hospital stay (5.9 ± 2.1 versus 3.4 ± 2.4 days; P < .001) and had greater blood loss (155 ± 62 mL). However, stone clearance rate (no remnant stone in postoperative X-ray of the kidney, ureter, and bladder) in a single session was marginally higher in the LU group (93.8% versus 68.8%; P = .06). Total complication rate was not significant and was slightly higher in the URS group (12.5% versus 21.9%, P = .51). Stone migration into the kidney (n = 2 versus 5), ureteral perforation (n = 0 versus 3), open conversion (n = 1 versus 2), and ureteral stricture (n = 1 versus 2), as long-term complications, occurred more frequently in the URS group.

CONCLUSIONS

For large proximal ureteral stones, LU can be conducted safely as a first-line procedure without increase of complication rate, compared with conventional URS. Although LU required a prolonged operative time and a longer hospital stay and blood loss was greater, our data showed an advantage of LU in high clearance rate in a single procedure.

Comparison of Patient Satisfaction with Treatment Outcomes between Ureteroscopy and Shock Wave Lithotripsy for Proximal Ureteral Stones

Purpose

We examined patient satisfaction with treatment outcomes after shock wave lithotripsy (SWL) and ureteroscopic removal of stone (URS) for proximal ureteral stones.

Materials and Methods

We evaluated 224 consecutive patients who underwent SWL (n=156) or URS (n=68) for a single radiopaque proximal ureteral stone. Stone-free rates, defined as no visible fragment on a plain X-ray; complications; and patient satisfaction were compared. Patient satisfaction was examined through a specifically tailored questionnaire that included overall satisfaction (5 scales) and 4 domains (pain, voiding symptoms, cost, and stone-free status).

Results

The stone-free rates after the first, second, and third sessions of SWL were 36.5%, 65.4%, and 84.6%, respectively. The overall stone-free rate of URS was 82.4%, which was comparable to that of the third session of SWL. Complications were similar between the two groups except for greater steinstrasse in the SWL group. Overall satisfaction and voiding symptoms, cost, and stone-free status showed no significant difference between the groups. In the pain domain, the SWL group had a relatively lower satisfaction rate than did the URS group (p=0.05). Subanalysis showed that the satisfaction rate of the URS group with stone-free status was significantly lower than that of the SWL group in patients with ≥10 mm stones (p=0.032).

Conclusions

Overall treatment outcomes and patient satisfaction were not significantly different between SWL and URS. However, patients undergoing URS for ≥10 mm proximal ureteral stones had lesser satisfaction with stone-free status, because of relatively lower stone-free rates due to upward stone migration. We suggest that factors regarding the subjective satisfaction of patients be included in counseling about treatment options for proximal ureteral stones.

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

Shock wave lithotripsy (SWL) is considered the first line treatment for the majority of patients with renal and ureteric calculi, with success rates from contemporary series varying from 60 to 90%. Success is dependent on many patient and stone-related factors. We conducted a retrospective analysis of mean stone CT density (MSD) and skin-to-stone distance (SSD) to determine their influence on the success of SWL of renal and ureteric calculi. Data from all patients treated at the St. Michael's Hospital Lithotripsy Unit from May 2004 to June 2009 were reviewed. Analysis was restricted to those patients with a pre-treatment non-contrast CT scan conducted at our center demonstrating a solitary renal or ureteric calculus < or =20 mm in maximal diameter. Successful treatment of renal stones was defined as those patients who were stone free or had asymptomatic, clinically insignificant residual fragments < or =4 mm in diameter, as measured by KUB X-ray, 3 months after a single SWL treatment. Successful treatment of ureteric stones was defined as being stone free on KUB X-ray, 2-weeks post-SWL. Demographic, stone, patient, treatment and follow-up data were collected from a prospective database and review of CT and KUB imaging by two independent urologists and one radiologist. Data were analyzed with logistic regression, Chi square analysis and ANOVA where appropriate. 422 patients (69.7% male) with a mean age of 51.4 years (SD 12.9) and mean BMI 27.0 kg/m(2) (SD 4.9) were analyzed. Mean stone size was 78.9 mm(2) (SD 77.3) for ureteral stones and 66.1 mm(2) (SD 63.2) for renal stones, with 95 (43.6%) of the renal stones located in the lower pole. The single-treatment success rates for ureteral and renal stones were 62.3% and 68.8%, respectively. On univariate analysis, predictors of SWL success, regardless of stone location, were age (p = 0.01), BMI (p = 0.01), stone size (p < 0.01), MSD (p < 0.01) and SSD (p < 0.01). On multivariate analysis, MSD >900 HU (OR = 0.49, CI: 0.32-0.75) and SSD >110 mm (OR = 0.49, CI: 0.31-0.78) were both significant predictors of outcome. We have identified in a large series of renal and ureteric calculi that both MSD and SSD can reliably predict SWL outcomes. This data can be used in combination with other patient and stone-related factors to facilitate optimal treatment-based decisions and provide patients with more accurate single-treatment success rates for SWL.

A prospective randomized study comparing shock wave lithotripsy and semirigid ureteroscopy for the management of proximal ureteral calculi

OBJECTIVES

To conduct a prospective randomized study comparing both techniques for the management of solitary radio-opaque upper ureteral stones < 2 cm in diameter. The ideal treatment for upper ureteral stones > 1 cm size remains to be determined with shock wave lithotripsy (SWL) and ureteroscopy (URS) being acceptable options.

METHODS

A total of 200 patients were included in the study. They were randomized into 2 equal groups. Group A underwent in situ SWL as a primary therapy. Group B underwent URS, using semirigid URS with intracorporeal lithotripsy. Efficiency quotient (EQ), cost analysis, and predictors of failure were estimated for both techniques.

RESULTS

For stones of size > or = 1 cm, the initial stone-free rate for URS and SWL was 88% and 60%, respectively. The estimated EQ was 0.79 and 0.43 for both techniques respectively. For stones < 1 cm, the initial stone-free rate for URS and SWL was 100% and 80%, respectively. The estimated EQ was 0.88 and 0.70 for both techniques, respectively. The mean cumulative costs were significantly more in SWL group (P <.05). Predictors of URS failure included; male gender, failure to pass guidewire beyond the stone, and extravasation. Predictors of SWL failure included large stone size > 1 cm, calcium oxalate monohydrate stone, and higher degrees of hydronephrosis.

CONCLUSIONS

URS with intracorporeal lithotripsy is an acceptable treatment modality for all proximal ureteral calculi, particularly stones > 1 cm. SWL should remain the first-line therapy for proximal ureteral calculi < or = 1 cm because of the less invasive nature and lower anesthesia (i.v. sedation).

[Influence of lithotripsy modalities on complication rate]

INTRODUCTION

Localization of ureteric stones and difference in disintegration success are the most important factors in determining the first treatment approach for ureteric stones.

OBJECTIVE

The aim of our study was to evaluate the difference in complication rate between different ureteric stone litho-tripsy modalities.

METHODS

Two hundred sixty patients with ureteric stones were analyzed in a prospective bicentric study that lasted 1 year.The patients were divided into two groups: 1-120 patients who underwent ESWL (extracorporeal shockwave lithotripsy) treatment and II-140 patients who were treated endoscopically with ballistic lithotripsy. RESULTS Ureteroscopic lithotripsy of all pelvic and iliac stones was significantly more successful comparing to ESWL, while lumbar ureteric stone treatment with ureteroscopic lithotripsy was not significantly more successful than ESWL, except for lumbar stones larger than 100mm2 that were significantly better treated endoscopically. In the I group complications after lithotripsy were recorded in 64 (59.3%) and in the II group in 58 (42.0%) patients, meaning that complications were statistically significantly more frequent in the I than in the II group. In the II group complications were significantly more often recorded after treatment of proximal comparing to ureteric stones of other localizations, while in the I group complica-tions were significantly more often detected after treatment of impacted stones than in the II group.

CONCLUSION

Being significantly successful comparing to ESWL, ureteric stone treatment with ureteroscopic lithotripsy should be considered as the first therapeutic option for all, especially impacted stones located in the iliac and pelvic ureteric portion. In spite of absent statistical difference in the success rate, ESWL should be chosen as the first treatment option in all cases of lumbar ureteric stones due to lower complication rate except for stones larger than 100mm2that should be primarily treated endoscopically.

Predictive role of renal resistance indices in the extracorporeal shock-wave lithotripsy outcome of ureteral stones

OBJECTIVE

Doppler ultrasonography (US) can be used to measure renal blood flow and calculate resistance indices. Increased renal resistance indices have been suggested to be associated with upper urinary tract obstruction and may help clinical physicians to differentiate physiological hydronephrosis from urinary tract obstruction. The aims of this study were to investigate the value of renal resistance indices before extracorporeal shock-wave lithotripsy (ESWL) and to determine whether they were predictive of the ESWL outcome.

MATERIAL AND METHODS

Between May 2005 and May 2006, a total of 84 patients who suffered from ureteral stones with renal colic and were treated with ESWL in the emergency department were enrolled in this study. Blood urea nitrogen and serum creatinine were determined and urinalysis, abdominal plain film X-ray and color Doppler US were performed. The resistive index (RI) and pulsatility index (PI) of the three different measurements of renal upper, middle and lower poles were calculated for both the affected and contralateral kidneys.

RESULTS

Sixty of the 84 patients were found to be stone-free after follow-up, and the total stone-free rate was 71%. There was a statistically significant difference between the mean RI of the affected and contralateral kidneys in all patients: 0.672+/-0.046 vs 0.616+/-0.054 (p<0.001). Moreover, there were statistically significant differences between the stone-free group and the residual stone group regarding the RI (0.651+/-0.046 vs 0.723+/-0.029, respectively; p=0.003) and PI (1.143+/-0.162 vs 1.262+/-0.145, respectively; p=0.03) of the affected kidney.

CONCLUSIONS

Intrarenal resistance indices represent the integration of arterial compliance, pulsatility, and peripheral resistance. Higher pre-ESWL resistance indices correlate with lower ESWL treatment success rates. Doppler US performed before ESWL treatment can therefore aid in making a correct clinical decision.

Does stone dimension affect the effectiveness of ureteroscopic lithotripsy in distal ureteral stones?

OBJECTIVE

To investigate whether stone dimension is a restrictive factor for ureterorenoscopic procedures.

MATERIALS AND METHODS

A group of 416 patients who had undergone ureterorenoscopic pneumatic lithotripsy (URS-PL) for lower ureteral stones between January 1999 and June 2006 in our clinic had been evaluated retrospectively. Two hundred and seventy (270, 64.9%) patients were men and 146 (35.1%) were women. The mean age of the patients was 36.61 (+/- 12.43) years. Patients were grouped according to stone dimension; 193 patients with stones smaller than 1 cm being group 1 and 223 patients with stones > or = 1 cm in dimension being group 2. Stone-free rate, operative time and rate of complications of the groups were compared. Pearson's correlation test, chi2 test, Fischer's exact test and Student's t-test were used for the statistical analysis. The p value was accepted as being meaningful if p < 0.05.

RESULTS

For group 1, the mean operative time was 39.19 (+/- 18.33) min. Proximal stone migration in five and false passage formation in three patients was observed. Three patients were stone-free after a second session of URS-PL. The cumulative stone-free rate was 97.4% (188/193). For group 2, the mean operative time was 48.5 (+/- 11.31) min. About 208 (93.27%) patients were stone-free after the first session and an additional eight patients became stone-free after the second session of URS-PL. False passage, ureteral perforation, ureteral avulsion and stricture were observed in four, six, one and one patients, respectively. No proximal stone migration was observed. The cumulative stone-free rate was 96.86% (216/223).

CONCLUSIONS

The effectiveness of ureterorenoscopy (URS) in the treatment of distal ureteral stones was independent of stone dimension. However, the operative time was longer and the rate of perforation was higher in stones with a diameter > or = 1 cm. On the other hand, the migration rate was higher in stones < 1 cm in diameter. Generally speaking, there was no meaningful effect of stone dimension on complication rates.

[The influence of lithotripsy methods on the incidence of auxilary procedures after ureteric stone desintegration]

INTRODUCTION/AIM

Localization of ureteric stones and the difference in disintegration success are the most important but not the only factors in choosing the first treatment approach to ureteric stones. The aim of the study was to investigate the incidence of auxiliary procedures after different ureteric stones lithotripsy modalities.

METHODS

In a prospective bicentric study 260 patients with ureteric stones were analyzed. The patients weve divided into two groups: group I--120 patients subjected to extracorporeal shock ware lithotripsy (ESWL) treatment and group II--140 patients treated endoscopicly with ballistic lithotripsy using "Swiss" Lithoclast.

RESULTS

Endoscopic treatment of all distal ureteric stones was significantly more successful than ESWL, but not significantly more successful than ESWL regarding proximal ureteric stones except for stones larger than 100 mm2 that were significantly better treated with endoscopic method. There was no general significant difference in auxiliary procedures rate after lithotripsy between the two groups. In the group I auxiliary procedures were significantly more performed than in the group II after the lithotripsy of stones larger than 100 mm2, calcium-oxalat-monohydrate stones and highly significantly more performed after the treatment of stones located in the iliac ureteric portion and impacted stones. After the lithotripsy of lumbar ureteric stones and multiple stones situated in different ureteric portions additional procedures were highly significantly more necessary in the goup II than in the group I.

CONCLUSION

Being significantly more successful comparing to ESWL, ureteric stone treatment with "Swiss" Lithoclast should be considered the first therapeutic option for all, especially impacted stones located in iliac and pelvic ureter. In spite of a statistically significant difference in success rate, ESWL should be performed as the first treatment option in all cases of lumbar stones as well as multiple stones located in different ureteric portion because of lower auxiliary procedures rate except for stones larger than 100 mm2 that should be primarily treated endoscopicly.

Stone attenuation and skin-to-stone distance on computed tomography predicts for stone fragmentation by shock wave lithotripsy

OBJECTIVES

To determine whether stone attenuation and the skin-to-stone distance (SSD) can predict for stone fragmentation by SWL independently. Identifying the factors predictive of shock wave lithotripsy (SWL) outcome would help streamline the care of patients with stones.

METHODS

A retrospective review was performed of 111 patients undergoing initial SWL for a solitary, 5-20 mm, renal calculus. Stone size, location, attenuation value, and SSD were determined on pretreatment noncontrast computed tomography. The outcome was categorized as stone free, complete fragmentation <5 mm, and incomplete fragmentation >or=5 mm or unchanged at 2 weeks on kidney/ureter/bladder radiography.

RESULTS

After SWL, 44 (40%) were stone free, 27 (24%) had complete fragmentation, and 40 (36%) of 111 patients had incomplete fragmentation. The stone attenuation of the successfully treated patients (stone free and complete fragmentation groups) was 837 +/- 277 Hounsfield units (HU) vs 1092 +/- 254 HU for those with treatment failure (incomplete fragmentation; P < .01). The mean SSD also differed: 9.6 cm +/- 2.0 vs 11.1 cm +/- 2.5 for the successful treatment group vs the treatment failure group, respectively (P = .01). On multivariate analysis, the factors that independently predicted the outcome were stone attenuation, SSD, and stone composition. When patients were stratified into 4 risk groups (stone <900 HU and SSD <9.0 cm, stone <900 HU and SSD >or=9.0 cm, stone >or=900 HU and SSD <9.0 cm, and stone >or=900 HU and SSD >or=9.0 cm), the SWL success rate was 91%, 79%, 58%, and 41%, respectively (odds ratio 7.1, 95% confidence interval 1.6-32 for <900 HU and SSD <9.0 cm group vs other 3 risk groups; P = .01).

CONCLUSIONS

The results of our study have shown that a stone attenuation of <900 HU, SSD of <9 cm, and stone composition predict for SWL success, independent of stone size, location, and body mass index. These factors will be considered important in the prospective design of a SWL treatment nomogram at our center.

Holmium laser lithotripsy for ureteral calculi: predictive factors for complications and success

PURPOSE

To define possible predictive factors for success and complications for ureteroscopic holmium laser lithotripsy procedures.

PATIENTS AND METHODS

All 105 ureteroscopic holmium laser lithotripsy procedures performed between 1996 and 2005 were analyzed. Data recorded were sex, age, stone size, stone location, complications, success rate (stone-free rate after 3 months), operative time, and surgeon experience for this procedure. For further analysis, surgeon experience was divided into four groups based on the number of procedures performed. Multivariate analysis was used to define possible predictive factors for complications and successful procedures.

RESULTS

Total success rate was 84.8%. Complications were present in 13 patients (12.4%). Success rate was significantly (P = 0.03) related to surgeon experience, with 92.9% success in the most experienced group and 50% in the least experienced group. Furthermore, significantly more complications occurred with decreased experience (P = 0.03): complication rate was 4.2% in the highest experience group and 41.7% in the least experienced group. In our series, sex, stone location, size, and age did not significantly influence complication and success rates.

CONCLUSION

Surgeon experience is a predictive factor for complications and success for ureteroscopic holmium laser lithotripsy for ureteric calculi. Experienced surgeons have fewer complications, and the success rate is higher. Sex, stone location, size, and age were not significantly related to complication or success rates.

How efficient is extracorporeal shockwave lithotripsy with modern lithotripters for removal of ureteral stones?

PURPOSE

To analyze results of extracorporeal shockwave lithotripsy (SWL) for treatment of ureteral stones with two modern lithotripters.

PATIENTS AND METHODS

A consecutive series of 598 patients with ureteral stones was treated with the Modulith SLX Classic and Modulith SLX-F2 lithotripters. The mean (SD) age of the patients was 54 (17) years, and the mean (SD) stone surface area was 42 (34) mm2. Results were available for 580 patients.

RESULTS

Stone-free ureters were recorded in 563 (97.1%) patients. Stone-free rates were 96.1%, 97.8%, and 97.9%, for the proximal, middle, and distal ureter, respectively. The average number of SWL sessions needed was 1.31. For the proximal, middle, and distal ureter, one SWL session was sufficient in 73.1%, 66.7%, and 83.2% of patients, respectively. Assisting auxiliary procedures were used in 102 patients (18%). The total mean (SD) treatment time was 48 (26) minutes and the mean (SD) number of shockwaves was 3266 (2258). SWL for stones located in the proximal, middle, and distal ureter was carried out in the prone position in 38%, 88%, and 9%, respectively. For 90 patients primarily treated with a large focus, the re-treatment rate was the same as for patients treated with a standard focus. A stone treatment index used to assess the efforts, results, and complications was similar for the two lithotripters and for all stone locations. Thus both lithotripters had similar efficacy.

CONCLUSION

With consistent use of SWL, a stone-free rate of more than 97% can be attained, with a reasonable re-treatment rate and only modest use of assisting auxiliary procedures.

[Importance of open and laparoscopic stone surgery]

INTRODUCTION

The increasing spread and technical enhancement of endourological methods has led to displacement of the surgical therapy of renal and ureteral calculi.

MATERIALS AND METHODS

Based on a review of current literature, we describe indications, technique, and clinical importance of the open and laparoscopic management of urolithiasis.

RESULTS

In Europe and North America, the surgical therapy of urolithiasis only plays a role in cases of very large or hard stones, after failure of shock wave lithotripsy, percutaneous nephrolithotripsy, or ureteroscopic stone removal, and in cases of abnormal renal anatomy, i.e., only in a few percent of all stone therapies. However, in developing countries and emerging markets with different structure and funding of the health care system where the methods of endourology are not readily available, these techniques still have a higher importance. Particularly in Europe, laparoscopic surgery is emerging because calculi can be removed from almost all locations in the kidney and ureter using a transperitoneal or retroperitoneal access. Functional outcomes and complication rates are comparable. The benefits of laparoscopy are less postoperative pain, shorter hospital stay, faster convalescence, and better cosmetic results.

CONCLUSIONS

Although procedures for open and laparoscopic removal of renal and ureteral calculi are only performed in rare cases in daily urological practice, they are superior to the endourological techniques in some circumstances. Therefore, they should still be part of the urologist's skills.

Percutaneous nephrostomy for removal of large impacted upper ureteral stones

The treatment for patients with large impacted proximal ureteral stone remains controversial. Extracorporeal shock wave lithotripsy and ureteroscopic lithotripsy are the most popular treatment options due to their minimal invasive nature. However, percutaneous nephroscopic ureterolithotripsy is still important. Between June 2004 and March 2006, a total of 24 patients under went percutaneous antegrade nephrostomy for the removal of large impacted proximal ureteral stones of size > 15 mm. Combined ultrasonic and pneumatic lithotripters were used for the stone fragmentation. Twenty-three (95.8%) of the 24 patients were stone-free after one session of surgery. The mean operation time was 125.4 +/- 49.5 minutes (range, 45-170 minutes) and the mean postoperative hospital stay was 4.7 +/- 2.0 days (range, 4-12 days). Among the 24 patients, six experienced transient postoperative fever that could be controlled with appropriate antibiotics and supportive treatment, and two had blood loss requiring blood transfusion. We suggest that percutaneous nephroscopic ureterolithotripsy is a safe and efficient treatment option for the removal of large impacted proximal ureteral stones.

Shock Wave Lithotripsy or Ureteroscopy for the Management of Proximal Ureteral Calculi: An Old Discussion Revisited

PURPOSE

The goal of treating ureteral calculi is to achieve complete stone clearance with minimal patient morbidity. Shock wave lithotripsy and ureteroscopy have become standards of care for ureteral calculi. However, the optimal choice of treatment depends on various factors, including stone size, composition and location, clinical patient factors, equipment availability and surgeon capability. Indications for and outcomes data on shock wave lithotripsy and ureteroscopy for proximal ureteral calculi were reviewed to provide recommendations on the optimal treatment choice for managing symptomatic ureteral calculi.

MATERIALS AND METHODS

A systematic review was performed based on an English literature search using the MEDLINE database between 1997 and 2005. The key words used were proximal ureteral calculi, ureteroscopy and shock wave lithotripsy.

RESULTS

A total of 87 articles were identified, of which 33 were selected for inclusion. Shock wave lithotripsy and ureteroscopy provided an excellent stone-free rate (86% to 90%) for stones less than 10 mm, whereas for larger stones ureteroscopy achieved better outcomes vs shock wave lithotripsy (67% vs 73%). Ureteroscopy was preferred over shock wave lithotripsy in patients with pregnancy or bleeding diathesis.

CONCLUSIONS

Ureteroscopy provides optimal stone clearance in patients with proximal ureteral calculi more than 10 mm. It is also recommended in patients with contraindications for shock wave lithotripsy. In patients with smaller stones (less than 10 mm) shock wave lithotripsy may be considered a reasonable alternative with outcomes similar to those of ureteroscopy.

Treatment Selection and Outcomes: Ureteral Calculi

The most important recent advances in the management of ureteral calculi have been the development of medical expulsive therapy to facilitate passage of ureteral stones, such that many calculi that would previously have required procedural treatment now exit the ureter with only pharmacologic treatment; and the improvements in ureteroscopic technology that have enabled retrograde ureteroscopy to become a first-line option for most ureteral stones. Shock wave lithotripsy still plays an important role for many ureteral calculi, particularly smaller ones, and the addition of percutaneous/antegrade ureteroscopy and laparoscopic ureterolithotomy rounds out the treatment options for large or impacted stones. Selection of treatment based upon factors such as size, location, and others will optimize outcome for patients who have ureteral calculi.