Factors predicting success of emergency extracorporeal shockwave lithotripsy (eESWL) in ureteric calculi--a single centre experience from the United Kingdom (UK)

Efficacy of emergency extracorporeal shock wave lithotripsy in the treatment of ureteral stones: a meta-analysis

OBJECTIVE

To compare the clinical efficiency and safety of emergency extracorporeal shock wave lithotripsy (eESWL) and delayed extracorporeal shock wave lithotripsy (dESWL) in the treatment of ureteral stones.

METHODS

Cochrane Library, PubMed, Google Scholar, and Web of Science were searched from January 1, 1992 to September 30, 2022, and all comparative studies involving eESWL and dESWL for ureteral calculi were included. Statistical analysis was performed using Review Manager 5.3 software. Funnel plot was used to evaluated publication bias.

RESULTS

A total of 9 articles involving 976 patients diagnosed with ureteral stones were included. The results showed that the stone-free rate (SFR) after four weeks was significantly higher in the eESWL group than in the dESWL group [relative risk (RR) = 1.22, 95% confidence interval (CI): 1.13-1.32, P < 0.01]. In subgroup analysis of different stone locations, proximal ureteral calculi [RR = 1.25, 95% CI: 1.14-1.38, P < 0.01] and mid-to-distal ureteral calculi [RR = 1.18, 95% CI: 1.03-1.34, P < 0.05] all showed a higher SFR in the eESWL group. eESWL significantly shortened the stone-free time(SFT) [mean difference (MD) = -5.75, 95% CI: -9.33 to -2.17, P < 0.01]. In addition, eESWL significantly reduced auxiliary procedures [RR = 0.53, 95% CI: 0.40-0.70, P < 0.01]. No significant difference in complications was found between the two groups [RR = 0.90, 95% CI: 0.69-1.16, P > 0.05].

CONCLUSION

eESWL can significantly improve SFR, shorten SFT, and reduce auxiliary procedures.

Development and validation of a predictive model for treatment outcome after emergency extracorporeal shockwave lithotripsy in patients with symptomatic ureteral stones during the COVID-19 pandemic: in a large prospective cohort

The predictors of treatment outcome after emergency extracorporeal shockwave lithotripsy (SWL) are not well characterized. Therefore, based on a large prospective cohort, we aimed to develop and validate a nomogram for predicting treatment outcome after emergency SWL in patients with symptomatic ureteral stones. The development cohort included 358 patients with symptomatic ureteral stones who underwent emergency SWL between June 2020 and August 2021 in our hospital. One hundred and twenty-nine patients with symptomatic ureteral stones participated in the validation cohort from September 2021 to April 2022. The data were prospectively recorded. The backward stepwise selection was applied using the likelihood ratio test with Akaike's information criterion as the stopping rule. The efficacy of this predictive model was assessed concerning its clinical usefulness, calibration, and discrimination. Finally, 15.6% (56/358) of patients in the development cohort and 14.0% (18/129) of those in the validation cohort suffered from stone-free failure after emergency SWL. We identified four predictors for stone-free failure: stone size, stone density, skin to stone distance (SSD), and degree of hydronephrosis. This model showed good discrimination with an area under the receiver operating characteristic (AUROC) curves of 0.935 (0.899-0.971) and good calibration (P = 0.059). The decision curve analysis showed that the model was clinically valuable. In this large prospective cohort, we found that stone size, stone density, SSD, and degree of hydronephrosis were predictors of treatment outcome after emergency SWL. This nomogram will be helpful in preoperative risk stratification to provide individualized treatment recommendations for each patient. Furthermore, early identification and appropriate management of patients may increase the success rate of emergency SWL during the COVID-19 pandemic.

Predictors of successful emergency shock wave lithotripsy for acute renal colic

The role of emergency shockwave lithotripsy (SWL) in persistent pain control in patients with ureteral stones is not well established. The aim of this study is to evaluate efficacy as well as the predicting variables for successful early SWL patients with symptomatic ureteral stones. Eighty-six patients with a persistent renal colic secondary to single ureteral stone (6–12 mm) were prospectively enrolled in this study. SWL was performed within 24 h of the onset of flank pain. Pain control and stone-free rate after emergency SWL session were 58.1% and 44.2%, respectively. Seven patients required post-SWL ureteroscopy and ureteral stent placement for uncontrolled pain. The overall 3-month stone-free rate after SWL monotherapy was 83.7%. On multivariate analysis, predictors for pain relief after emergency SWL were lower Hounsfield (HU) stone density, mild hydronephrosis (HN) at presentation and presentation during the first colic episode. Lower HU stone density was the single predictor of successful stone clearance after single emergency SWL session on multivariate analysis. In conclusion, early SWL is feasible and effective in management of ureteral stones presented by renal colic with low HU.

The impact of delaying acute kidney stone surgery on outcomes

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Emergency extracorporeal shockwave lithotripsy as opposed to delayed shockwave lithotripsy for the treatment of acute renal colic due to obstructive ureteral stone: a prospective randomized trial

BACKGROUND

The aim of this study was to assess the efficacy of emergency extracorporeal shockwave lithotripsy (eSWL) as first-line treatment in patients with acute colic due to obstructive ureteral stone.

METHODS

Seventy-four patients were randomized to emergency SWL within 12 hours (eSWL group) and deferred SWL later than 3 days (dSWL group). Follow-up included ultrasound, KUB (kidney-ureter-bladder) radiography and CT (computed tomography) scan at 24 hours, 7 days, 1 and 3 months from the treatment. When necessary, repeated SWL (re-SWL) or ureteroscopy (auxiliary-URS) was performed. Preoperative and postoperative data were compared and stone free rates (SFR) and efficiency quotients (EQ) were evaluated. Analyses were performed using SAS software.

RESULTS

Complete data of 70 patients were collected. 36 underwent eSWL and 34 dSWL. The mean patient age was 48.7. Mean stone size was 9.8 mm (CI 95%: 8.9-10.8). 25 (35.7%) were proximal and 45 (64.3%) distal. Mean SWL energy was 19.2 kV (CI 95%: 18.5-19.9) and mean number of shocks was 2657 (CI 95%: 2513-2802). eSWL patients needs less auxiliary-URS than dSWL patients (13.9% vs. 44.1%, P=0.039) and less re-SWL sessions (8.3% vs. 32.4%, P=0.093). SFR at 24 hours was 52.8% and 11.8% (P<0.001) and the EQ at 3 months was 79.1% and 57.5% in the eSWL and dSWL group respectively. Patients from the dSWL group spent more time in the hospital (2.21 vs. 1.36 days, P=0.046) and complication rates between the two groups were similar.

CONCLUSIONS

eSWL is a safe procedure and delivers high SFR even within 24 hours especially for <10 mm stones. It is able to reduce the number of auxiliary procedures and hospitalization.

Predicting stone composition before treatment - can it really drive clinical decisions?

Introduction

Determination of stone composition is considered to be crucial for the choice of an optimal treatment algorithm. It is especially important for uric acid stones, which can be dissolved by oral chemolysis and for renal stones smaller than 2 cm, which can be treated with extracorporeal shockwave lithotripsy (ESWL).

Material and methods

This short review identifies the latest papers on radiological assessment of stone composition and presents a comprehensive evaluation of current scientific findings.

Results

Stone chemical composition is difficult to predict using standard CT imaging, however, attenuation index measured in Hounsfield units (HU) is related to ESWL outcome. Stone density >1000 HU can be considered predictive for ESWL failure. It seems that stone composition is meaningless in determining the outcome of ureterolithotripsy and percutaneous surgery. Alternative imaging techniques such as Dual–Energy CT or analysis of shape, density and homogeneity of stones on plain X–rays are used as promising methods of predicting stone composition and ESWL outcome.

Conclusions

New imaging techniques facilitate the identification of uric acid stones and ESWL–resistant stones. Therefore, they may help in selecting the best therapeutic option.

Extracorporeal shockwave lithotripsy for upper tract urolithiasis

PURPOSE OF REVIEW

For the last three decades, extracorporeal shockwave lithotripsy (SWL) has been the mainstay of management of urolithiasis; recognized widely by patients and physicians for its noninvasive approach and good outcomes. Recent challenges by endoscopic approaches have driven ongoing research to refine indications, define outcomes and explore innovations.

RECENT FINDINGS

Utilization of SWL remains high, despite increasing utilization of endoscopic approaches. Patient selection is critical--outcomes with percutaneous nephrolithotomy and ureteroscopy after failed SWL are not as good as those obtained in patients who have not had prior SWL. A structured training in ultrasound localization and proper patient positioning can have dramatic impacts on stone-free results. Stone size, location, Hounsfield unit stone attenuation and stone volume remain important predictors of outcomes. Renal cysts may negatively impact outcomes with SWL.

SUMMARY

These recent studies highlight important considerations for patient selection, SWL technique and follow-up for patients undergoing SWL. New technologies hold promise but require further study.