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

Comparing the efficacy of extracorporeal shock wave lithotripsy and ureteroscopic lithotripsy in the treatment of proximal ureteral stones in children: A retrospective study

OBJECTIVES

Ureteroscopic lithotripsy and extracorporeal shock wave lithotripsy methods are commonly used in the treatment of proximal ureteral stones. There are no adequate studies showing which method is more effective in children. In our study, we aimed to evaluate and compare the efficacy of two treatment methods, commonly used for proximal ureteral stones in children.

METHODS

A total of 78 patients who underwent ureteroscopic lithotripsy (n = 38) and extracorporeal shock wave lithotripsy (n = 40) due to stones located in the proximal ureter between 2010 and 2021 were included in the study. Demographic data, clinical characteristics, and treatment outcomes were retrospectively analyzed. Kolmogorov-Smirnov, Chi-square, and Mann-Whitney U tests were used for statistical analysis.

RESULTS

There was no statistical difference between the demographic characteristics of the groups, except for the mean age values (p = 0.008). A statistically significant difference was found in favor of the extracorporeal shock wave lithotripsy group in terms of stone-free rates after the first intervention, complication rates requiring intervention, re-intervention rates, and the average number of anesthesia sessions per patient until stone-free status (p = 0.043, p = 0.009, p = 0.017, and p < 0.001, respectively).

CONCLUSIONS

The results of this retrospective study suggest that extracorporeal shock wave lithotripsy is the primary treatment option for single, non-complicated proximal ureteral stones.

Extracorporeal shock wave lithotripsy for urinary tract stones in pediatric patients: Our 11 years of experience

Background/Aim: Urinary system stone disease creates a significant burden on the health system. Many treatment methods are available, including extracorporeal shock wave lithotripsy (ESWL), endourological procedures, and open and laparoscopic procedures. In recent years, in parallel with technological developments, endourological devices have become more usable in the renal system. For this reason, urologists are opting for endourological procedures more frequently. ESWL is the least invasive procedure for urinary system stone disease, and it has a higher success rate in pediatric patients than in adults. In this retrospective cohort study, we analyzed the data from the pediatric cases in which we used ESWL treatment in our clinic. We aimed to reveal the effectiveness of ESWL and the factors that will increase the success rate of this procedure in light of the current literature. Methods: The files of patients aged 16 years and under who underwent ESWL at the Urology Clinic of University of Health Sciences Sanliurfa Mehmet Akif Inan Training and Research Hospital between January 2010 and December 2021 were retrospectively reviewed. Age, gender, stone area, stone localization, number of sessions, energy and frequency used, complete stone-free status, and secondary intervention requirement were recorded. The absence of stone fragments or the presence of fragments smaller than 3 mm only in imaging after ESWL was considered a success. Results: This study included 433 pediatric patients. The mean age of the patients was calculated as 12.02 (4.67) (range: 1–16) years. The most important factors affecting the number of residual stones were stone localization (P = 0.045) and size (P < 0.001). When stone localization was compared according to patient age, the older patients were found to have a significantly higher rate of stones in the proximal ureter than in the lower calyx of the kidney (P = 0.045) and renal pelvis (P = 0.048). Conclusion: Although there are continual advances in other minimally invasive surgical methods today, ESWL is a treatment method that can be safely applied in pediatric patients. Stone size and stone localization are the two most important factors affecting its success rate.

Paediatric stone management: innovations and standards

PURPOSE OF REVIEW

The aim of this study was to discuss current trends and recent developments in the surgical management of paediatric urolithiasis.

RECENT FINDINGS

Medical expulsive therapy (MET) is considered as an option for the treatment of children with ureter stones. Extracorporeal shockwave lithotripsy (SWL) remains as a first option for majority of kidney stones and upper ureter stones. Advances in endourology have led to increased adoption of retrograde intrarenal surgeries (RIRS) and percutaneous nephrolithotomy (PCNL/mini-PCNL/ultra-mini-PCNL/micro-PCNL).

SUMMARY

Management of paediatric stone disease has developed significantly in the past decade. However, the evidence in the literature remains disproportional to these advances. Well designed multicentric studies are still needed to compare effectiveness and safety of these procedures.

Factors to predict shock-wave lithotripsy results in pediatric patients and external validation of a nomogram

OBJECTIVE

To evaluate the accuracy of the Dogan nomogram in predicting stone-free (SF) rate after a single shock wave lithotripsy (SWL) session and evaluate factors that predict SWL results in children.

PATIENTS AND METHODS

The study included 68 patients under 18 years of age who had been treated with SWL for radiopaque upper urinary tract stones in our tertiary centre from January 2010 to December 2016. The median age is 50 (6-207) months and median follow-up period is 9 (4-50) months. Patients with known cystine stone disease, abnormal renal anatomy, urinary diversion and multiple stones located in different calyces were excluded like in the original nomogram study. SF status was evaluated by performing plain abdominal radiography and urinary ultrasonography 2 weeks after each SWL session. Patients who were completely free of stones were considered to be SF. Multiple logistic regression analyses were performed to determine the variables affecting SF status. The bootstrap method with 1,000 replicates was used for the external validity of a nomogram developed by Dogan.

RESULTS

SF rates for each SWL session were determined as 54.4% (37/68) for the first session, 33.3% (7/21) for the second session and 55.6% (5/9) for the third session. Overall, the SF rate was 72.1% (49/68). Multiple logistic regression analysis showed positive and significant correlations of age and stone size with risk of SWL failure. The external calibration plot showed a nearly good validation with Dogan nomogram to predict SWL failure in first session.

CONCLUSION

Our study demonstrates that the Dogan nomogram can be used to predict the SF status after one session of SWL in pediatric patients.

Comparison of extracorporeal shockwave lithotripsy and retrograde intrarenal surgery in the treatment of renal pelvic and proximal ureteral stones ≤2 cm in children

Introduction:

We aimed to compare extracorporeal shockwave lithotripsy (ESWL) and retrograde intrarenal surgery (RIRS) in pediatric patients with ≤2 cm renal pelvis and proximal ureteral stones.

Methods:

Medical records of 165 pediatric patients who underwent shockwave lithotripsy (SWL) or RIRS for upper urinary system stones up to 2 cm between January 2014 and December 2018 were retrospectively reviewed. After exclusions, the remaining 130 patients included 73 in the SWL group and 57 in the RIRS group. The groups were compared for demographic features, stone characteristics, operative data, success, and complications.

Results:

The mean stone volume was 308 ± 85 (54–800) and 336 ± 96 (60–720) mm³ in SWL and RIRS groups, respectively (P = 0.46). There were no significant differences in success rates (60% vs. 70%, SWL and RIRS), auxiliary treatment rates (16.4% vs. 14%), and complication rates (26% vs. 24.5%). The number of active procedural sessions and number of anesthesia sessions was higher in the RIRS group (P < 0.001 and P < 0.001, respectively), while the procedural time and anesthesia time were higher in the SWL group (P < 0.001 and P < 0.001, respectively). Stone size was found to be an independent success predictive factor for both the treatment modalities.

Conclusions:

Both SWL and RIRS have similar success, complication, and auxiliary treatment rates. RIRS was superior in terms of total procedure and anesthesia durations, while SWL was superior in terms of numbers of anesthesia sessions and active procedure sessions. As both have similar success rates, the more minimally invasive SWL should be chosen for pediatric upper urinary system stones of less than 2 cm size.

Imaging modalities and treatment of paediatric upper tract urolithiasis: A systematic review and update on behalf of the EAU urolithiasis guidelines panel

BACKGROUND

Prompt diagnosis and treatment of paediatric urolithiasis are required to avoid long term sequelae of renal damage.

OBJECTIVE

To systematically review the literature regarding the diagnostic imaging modalities and treatment approaches for paediatric urolithiasis.

STUDY DESIGN

PubMed, Science Direct, Scopus and Web of Science were systematically searched from January 1980-January 2019. 76 full-text articles were included.

RESULTS

Ultrasound and Kidney-Ureter-Bladder radiography are the baseline diagnostic examinations. Non-contrast Computed Tomography (CT) is the second line choice with high sensitivity (97-100%) and specificity (96-100%). Magnetic Resonance Urography accounts only for 2% of pediatric stone imaging studies. Expectant management for single, asymptomatic lower pole renal stones is an acceptable initial approach, especially in patients with non-struvite, non-cystine stones<7 mm. Limited studies exist on medical expulsive therapy as off-label treatment. Extracorporeal shock wave lithotripsy (SWL) is the first-line treatment with overall stone free rates (SFRs) of 70-90%, retreatment rates 4-50% and complication rates up to 15%. Semi-rigid ureteroscopy is effective with SFRs of 81-98%, re-treatment rates of 6.3-10% and complication rates of 1.9-23%. Flexible ureteroscopy has shown SFRs of 76-100%, retreatment rates of 0-19% and complication rates of 0-28%. SFRs after first and second-look percutaneous nephrolithotomy (PNL) are 70.1-97.3% and 84.6-97.5%, respectively with an overall complication rate of 20%. Open surgery is seldom used, while laparoscopy is effective for stones refractory to SWL and PNL. Limited data exist for robot-assisted management.

CONCLUSIONS

In the initial assessment of paediatric urolithiasis, US is recommended as first imaging modality, while non-contrast CT is the second option. SWL is recommended as first line treatment for renal stones <20 mm and for ureteral stones<10 mm. Ureteroscopy is a feasible alternative both for ureteral stones not amenable to SWL as well as for renal stones <20 mm (using flexible). PNL is recommended for renal stones >20 mm.

Update on Surgical Management of Pediatric Urolithiasis

Urolithiasis has always been a fascinating disease, even more so in children. There are many intriguing facets to this pathology. This article is a nonsystematic review to provide an update on the surgical management of pediatric urolithiasis. It highlights the pros and cons of various minimally invasive surgical options such as extracorporeal shockwave lithotripsy (ESWL), retrograde intrarenal surgery (RIRS), percutaneous nephrolithotomy (PCNL), laparoscopy, and robotics. This article also describes the various intracorporeal disintegration technologies available to fragment the stone, including the newer advancements in laser technology. It also emphasizes the cost considerations especially with reference to the emerging economies. Thus, this manuscript guides how to select the least-invasive option for an individual patient, considering age and gender; stone size, location, and composition; and facilities and expertise available.

SWL outcome in artificial hydronephrotic vs. non-hydronephrotic kidney for preschool children with high-density renal stones

OBJECTIVE

To assess the effect of artificial hydronephrosis on the result of shock wave lithotripsy (SWL) in preschool children.

MATERIALS AND METHODS

A prospective randomized trial was performed between January 2013 and January 2017 with 300 pediatric patients, having kidney stones with a size of 1-2 cm and a density of 750-1100 HU. The patients were randomized into two groups: group A, in which a ureteric catheter was fixed and artificial hydronephrosis was performed by fluid irrigation prior to SWL, and group B which did not undergo hydronephrosis. SWL outcomes were compared between two groups.

RESULTS

In total, 153 cases were assigned to group A, and 147 cases were assigned to group B. Regarding demographic data, there was no statistically significant difference between the two groups. There were also no statistically significant differences in the number of shocks and energy power needed for each group. The results of SWL after the first session favored group A with a stone-free rate (SFR) of 90.8% vs. 75.5% for group B. The SFR after SWL was significantly in favor of group A (94.1%) vs. (86.4%) for group B.

CONCLUSION

The use of an artificial hydronephrosis technique to make interface around the stone improves stone-free rate and decreases the need for retreatment after SWL.

Predictive factors and treatment outcomes of Steinstrasse following shock wave lithotripsy for ureteral calculi: A Bayesian regression model analysis

Purpose

This study aims to assess the predictive factors and treatment outcomes of Steinstrasse formation following shock wave lithotripsy (SWL) for ureter stone.

Materials and Methods

The medical records of 1,418 ureter stone patients who underwent one-session SWL from November 2005 to May 2013 at our medical institute were retrospectively reviewed. Finally, 551 patients met inclusion criteria. Maximal length and location of stone, stone attenuation (Hounsfield units), and skin-to-stone distance (SSD) were determined on pretreatment non-contrast computed tomography.

Results

Of 551 patients, 12 patients (2.2% of total cohort) developed Steinstrasse after one-session SWL. The Steinstrasse incidence was significantly associated with stone size, stone attenuation value, and SSD. Prophylactic ureter stenting was not a statistically significant predictor of Steinstrasse formation. After propensity-score matching, Steinstrasse group showed a significant shorter SSD compare to non-Steinstrasse group. Multivariate logistic regression and Bayesian analysis revealed that stone size, stone attenuation and SSD were significant predictor of Steinstrasse formation following SWL for ureter stone. The Steinstrasse resolved spontaneously in six patients and remaining six patients were treated by additional SWL. None of patients with Steinstrasse required ureteral stenting, percutaneous drainage, or consequent surgical intervention.

Conclusions

Steinstrasse formation following SWL for ureter stone was rare event but nonnegligible. Large stone size, high stone attenuation and short SSD were significant predictors of Steinstrasse formation following SWL for ureter stone. Majority of patients with Steinstrasse formation could be treated conservatively in this clinical scenario.

Extracorporeal shock wave lithotripsy (ESWL) monotherapy in children: Predictors of successful outcome

INTRODUCTION AND OBJECTIVES

Although extracorporeal shock wave lithotripsy (ESWL) is the first choice for pediatric renal calculi <2 cm, the success rate after the first session is low. This is in contrast to other minimally invasive procedures like percutanous nephrolithotomy (PCNL) and retrograde intrarenal surgery (RIRS), which have higher rates of success. Therefore, the present study sought to identify predictors of success after one session of ESWL.

PATIENTS AND METHODS

A prospective study including 100 children with renal stone burden <2 cm who underwent ESWL at the present institution. The success rate after the first session was analyzed, and the predictors of success were investigated. The success of ESWL monotherapy was defined by absence of any residual fragments after 3 months, on non-contrast spiral computerized tomography (NCCT) scan, without need of any additional intervention.

RESULTS

Between January 2013 and October 2015, 100 children were treated with a Dornier Gemini lithotripter at the present institution. The mean patients age and stone size were 6 years (range: 1.8-14) and 13.1 mm (range: 6-20), respectively. After one session, 47% of patients showed complete clearance 3 months postoperative, those patients versus those who required an additional session or auxiliary procedures were younger in age, with smaller stone size and lower density. On multivariate analysis, only patient age was an independent predictor of success (odds ratio (OR) 0.9; P < 0.001).

CONCLUSION

Patient's age was an important predictor for response after ESWL monotherapy: not only did children respond better than adults, but age was also an independent predictor within the pediatric group.

Extracorporeal Shock Wave Lithotripsy Management of Renal Stones in Children: Does Anesthesia Affect the Treatment Outcomes on an Age-based Manner?

OBJECTIVE

To evaluate beneficial effect of anesthesia on extracorporeal shock wave lithotripsy (SWL) in children older than 9 years.

PATIENTS AND METHODS

A total of 61 children (aged between 9 and 17 years) treated with SWL for renal stones were included. Depending on the use of general anesthesia, the children were divided into 2 groups: cases treated with SWL under anesthesia (group 1, n = 27) and cases treated with SWL without anesthesia (group 2, n = 34). The patients in both groups were comparatively evaluated with respect to treatment-related parameters (stone size, stone laterality, stone location, mean number of sessions, mean number of shock waves applied, residual fragments size, stone-free rate [SFR], clinically significant residual fragment complications, and need for additional intervention). The efficacy quotient was also evaluated.

RESULTS

The overall mean stone size was 10.48 ± 4.27 mm. Although there was no significant difference regarding the stone size (P = .924), stone laterality (P = .240), stone localization (P = .084), mean number of sessions (P = .392), SFR (P = .666), clinically significant residue (P = .526), size of residual fragments (P = .315), complication rates (P = 1.000), and need for additional intervention (P = 1.000), the mean number of shock waves applied was significantly higher in patients treated without anesthesia (group 2) (P = .001). The efficacy quotient was 41.7% and 35.4% for groups 1 and 2, respectively.

CONCLUSION

Our findings indicate that anesthesia-free SWL for renal stones in children aged older than 9 years is feasible and successful with similar treatment outcome data observed in cases with the same age range being treated under anesthesia. We believe that SWL without anesthesia can be applied in a safe and successful manner in relatively older and cooperative children.

Lower calyceal and renal pelvic stones in preschool children: A comparative study of mini-percutaneous nephrolithotomy versus extracorporeal shockwave lithotripsy

OBJECTIVES

To compare outcomes of the mini-percutaneous nephrolithotripsy technique and extracorporeal shockwave lithotripsy for lower calyceal and renal pelvic stones in preschool children.

METHODS

From January 2010 to December 2014, single renal pelvic or lower calyceal calculi 10-25 mm in size in children (age ≤6 years) treated by either extracorporeal shockwave lithotripsy (64 patients) or the mini-percutaneous nephrolithotripsy technique (54 patients) were included. Extracorporeal shockwave lithotripsy was carried out by using a Dornier electromagnetic lithotripter. The mini-percutaneous nephrolithotripsy technique was through 14-Fr renal access using a 9.5-Fr semirigid ureteroscope with holmium:yttrium aluminium garnet lithotripsy. The two study groups were compared using Mann-Whitney, χ(2) -test or Fisher's exact test.

RESULTS

Stone parameters were similar in the mini-percutaneous nephrolithotripsy technique and extracorporeal shockwave lithotripsy groups in all patients, and in the pelvic (39 Miniperc, 52 extracorporeal shockwave lithotripsy) and lower calyceal (15 Miniperc, 12 extracorporeal shockwave lithotripsy) subgroups. Stone-free rates in the mini-percutaneous nephrolithotripsy technique and extracorporeal shockwave lithotripsy groups were 88.9% versus 43.8% (P < 0.001) and 94.4% versus 81.2% (P = 0.032) after first and last sessions, respectively. In the renal pelvis, they were 87.2% versus 50% (P < 0.001) and 94.9% versus 84.6% (P = 0.179), whereas in the lower calyx, they were 93.3% versus 16.7% (P < 0.001) and 93.3% versus 66.7% (P = 0.139) after first and last sessions, respectively. Retreatment rates in the mini-percutaneous nephrolithotripsy technique versus extracorporeal shockwave lithotripsy were 7.4% versus 50% (P < 0.001), 7.7% versus 46.2% (P < 0.001), and 6.7% versus 66.7% (P = 0.003) in all patients, renal pelvic and lower calyceal stones, respectively. No significant difference was found in complications (P = 0.521). Auxiliary procedures were required in 9.4% and 1.9% of children in the extracorporeal shockwave lithotripsy and mini-percutaneous nephrolithotripsy technique groups, respectively.

CONCLUSIONS

The mini-percutaneous nephrolithotripsy technique has significantly higher stone-free rates than extracorporeal shockwave lithotripsy for renal pelvic and lower calyceal stones (10-25 mm), with a lower retreatment rate and without a significant increase in complications.