Impact of Pretreatment Hydronephrosis on the Success Rate of Shock Wave Lithotripsy in Patients with Ureteral Stone

Factors influencing the efficacy of ultrasound-guided extracorporeal shockwave lithotripsy in the treatment of ureteral stones: a retrospective study

The aim of the study was to analyze the factors influencing the efficacy of ultrasound-guided extracorporeal shockwave lithotripsy (ESWL) in the treatment of ureteral stones. The clinical data of 8102 patients (6083 men and 2019 women) who presented with ureteral stones were retrospectively analyzed. All the patients were treated with ultrasound-guided ESWL. The stone-free rate (SFR) was calculated to evaluate the effect of ESWL. The characteristics of the patients and their stones, and the ESWL parameters applied were compared to identify the factors affecting the treatment outcomes. The SFR and that following one ESWL session were 94.6% (7663/8102) and 75.4% (6107/8102), respectively. Multivariate analysis showed that stone location (OR 0.656, p < 0.001), stone size (OR 1.103, p < 0.001), and degree of hydronephrosis (OR 1.952, p < 0.001) independently affected SFR; and age (OR 1.005, p = 0.022), stone location (OR 0.729, p < 0.001), stone size (OR 1.103, p < 0.001), degree of hydronephrosis (OR 1.387, p = 0.001), maximum energy level(OR 0.691, p < 0.001) independently affected SFR following one session. Ultrasound-guided ESWL is effective in all levels of ureteral stones. Large stone size and moderate hydronephrosis are correlated with treatment failure. Ultrasound-guided ESWL may be the first choice for distal ureteral stones.

The First 100 Cases of Endoscopic Combined Intrarenal Surgery in Korea: Matched Cohort Analyses versus Shock-Wave Lithotripsy

PURPOSE

This study presents our initial experience with endoscopic combined intrarenal surgery (ECIRS) for large renal stones and compares the results of a propensity score-matched cohort of patients undergoing shock-wave lithotripsy (SWL).

MATERIALS AND METHODS

A total of 100 adults underwent ECIRS for renal stones between August 2017 and January 2019. For comparison, 2172 patients who underwent a first session of SWL between January 2005 and May 2018 were included in the SWL cohort. Propensity score matching was performed using maximal stone length (MSL), mean stone density (MSD), and stone heterogeneity index (SHI) scores. Stone-free rate (SFR) and success rate were compared between ECIRS and SWL.

RESULTS

In the ECIRS group, the mean MSL, mean MSD, and mean SHI were 28.7±15.2 mm, 1013.9±360.0 Hounsfield units (HU), 209.4±104.0 HU, respectively. The SFR was 70%, and the success rate was 82.0% in this group. Although the ECIRS group had larger, harder, and more homogeneous stones than the SWL group, ECIRS showed a higher SFR and success rate than SWL. After propensity-score matching, SFR and success rate remained higher with ECIRS than with SWL (both, p<0.001). In multivariate logistic regression, smaller stone size [odds ratio (OR): 0.947, 95% confidence interval (CI): 0.913-0.979, p=0.002] and lower Seoul National University Renal Stone Complexity score (OR: 0.759, 95% CI: 0.610-0.935, p=0.011) were independent predictors of successful ECIRS.

CONCLUSION

ECIRS showed a higher SFR and success rate than SWL for large renal stones. Smaller stone size and lower complexity of stones were associated with a higher likelihood of successful ECIRS.

Relationship between microscopic haematuria and hydronephrosis in urolithiasis

AIM

The aim of this study was to investigate the relationship between the degree of hydronephrosis and the presence of microscopic haematuria in patients who presented to the emergency department (ED) with ureteral stones.

METHODS

The records of patients who presented to our ED due to urolithiasis between January 2017 and December 2020 were retrospectively analysed. Patients aged 18 years or older who underwent non-contrast computed tomography (CT abdomen/pelvis) and urinalysis (UA) and were diagnosed with ureteral stones were included in the study. Radiology reports were reviewed for stone size, localisation and degree of hydronephrosis. Patients with and without microscopic haematuria and the degree of hydronephrosis were compared.

RESULTS

A total of 476 patients were included, which consisted of 391 with microscopic haematuria and 85 without microscopic haematuria. The median stone size was 4.1 mm in the presence of microscopic haematuria and 5.5 mm in the absence of microscopic haematuria. Logistic regression analysis was performed to determine the factors associated with the development of hydronephrosis. Stone size [odds ratio (OR):2.15, 95% confidence interval (CI):1.12-4.16, P < .001), presence of pyuria (OR: 2.58, 95% CI: 1.78-3.48, P < .001) and absence of microscopic haematuria (OR: 1.31, 95% CI 1.04-2.89, P = .017) were identified as risk factors for moderate and severe hydronephrosis.

CONCLUSION

We consider that imaging studies may be necessary for the diagnosis, and treatment of emergency cases in which microscopic haematuria is not detected in urinalysis since their stone size may be larger and degree of hydronephrosis may be more severe.

Surgical and radiological predictive factors for ureteric stricture formation in patients treated with ureteroscopy for ureteric stones

BACKGROUND

Ureteric stricture is a potential complication of impacted ureteric stones. This study investigates surgical and radiological factors that could predict ureteric stricture formation after ureteroscopic treatment of impacted ureteric stones.

MATERIALS AND METHOD

Intraoperative and radiological data for patients who underwent ureteroscopic treatment of ureteric stones impaction over a 5-year period were reviewed retrospectively. Patients who had previous ureteroscopic treatment or strictures were excluded.

RESULTS

Between January 2014 and May 2019, 1,340 patients presented as emergency renal colic secondary to ureteric stones. A total of 297 ureteroscopy procedures were performed for impacted calculi. The mean age was 53 years. The stricture rate was 3.3%. Analysis of radiological and surgical factors revealed that the degree of hydronephrosis, residual fragments and intraoperative ureteric injury were significant predictors for stricture formation (p = 0.018, 0.01 and 0.02, OR = 10, 47 and 1776, respectively). None of the other factors significantly predicted ureteric stricture formation.

CONCLUSION

Our study found the presence of severe hydronephrosis, residual stone fragments after surgery and intraoperative ureteric injury are significant predictive factors for ureteric stricture formation. The high-risk patients should be monitored with routine postoperative renal ultrasound.

Effectiveness of Percutaneous Nephrolithotomy, Retrograde Intrarenal Surgery, and Extracorporeal Shock Wave Lithotripsy for Treatment of Renal Stones: A Systematic Review and Meta-Analysis

Background and objectives: To perform a updated systematic review and meta-analysis comparing effectiveness of percutaneous nephrolithotomy (PCNL), retrograde intrarenal surgery (RIRS), and extracorporeal shock wave lithotripsy (ESWL) for treatment of renal stones (RS). Materials and Methods: A total of 37 studies were included in this systematic review and meta-analysis about effectiveness to treat RS. Endpoints were stone-free rates (SFR), incidence of auxiliary procedure, retreatment, and complications. We also conducted a sub-analysis of ≥2 cm stones. Results: First, PCNL had the highest SFR than others regardless of stone sizes and RIRS showed a higher SFR than ESWL in <2 cm stones. Second, auxiliary procedures were higher in ESWL than others, and it did not differ between PCNL and RIRS. Finally, in <2 cm stones, the retreatment rate of ESWL was higher than others. RIRS required significantly more retreatment procedures than PCNL in ≥2 cm stones. Complication was higher in PCNL than others, but there was no statistically significant difference in complications between RIRS and PCNL in ≥2 cm stones. For ≥2 cm stones, PCNL had the highest SFR, and auxiliary procedures and retreatment rates were significantly lower than others. Conclusions: We suggest that PCNL is a safe and effective treatment, especially for large RS.

Effectiveness of Percutaneous Nephrolithotomy, Retrograde Intrarenal Surgery, and Extracorporeal Shock Wave Lithotripsy for Treatment of Renal Stones: A Systematic Review and Meta-Analysis

Background and objectives: To perform a updated systematic review and meta-analysis comparing effectiveness of percutaneous nephrolithotomy (PCNL), retrograde intrarenal surgery (RIRS), and extracorporeal shock wave lithotripsy (ESWL) for treatment of renal stones (RS). Materials and Methods: A total of 37 studies were included in this systematic review and meta-analysis about effectiveness to treat RS. Endpoints were stone-free rates (SFR), incidence of auxiliary procedure, retreatment, and complications. We also conducted a sub-analysis of ≥2 cm stones. Results: First, PCNL had the highest SFR than others regardless of stone sizes and RIRS showed a higher SFR than ESWL in <2 cm stones. Second, auxiliary procedures were higher in ESWL than others, and it did not differ between PCNL and RIRS. Finally, in <2 cm stones, the retreatment rate of ESWL was higher than others. RIRS required significantly more retreatment procedures than PCNL in ≥2 cm stones. Complication was higher in PCNL than others, but there was no statistically significant difference in complications between RIRS and PCNL in ≥2 cm stones. For ≥2 cm stones, PCNL had the highest SFR, and auxiliary procedures and retreatment rates were significantly lower than others. Conclusions: We suggest that PCNL is a safe and effective treatment, especially for large RS.

Does Early Retrograde Intrarenal Surgery Improve the Cost-Effectiveness of Renal Stone Management?

PURPOSE

This study aimed to evaluate the cost-effectiveness of treatment with retrograde intrarenal surgery (RIRS) versus repeated shock wave lithotripsy (SWL) in patients with renal calculi.

MATERIALS AND METHODS

The non-retreatment rates (NRRs) and their respective real-world costs for RIRS and SWL were derived through retrospective analysis of health insurance claims data from 2015 to 2017. Decision tree modeling was performed to demonstrate the cost-effectiveness of RIRS. Furthermore, sensitivity analysis was performed to examine the robustness of the results.

RESULTS

Analysis of the obtained data showed that NRRs of single SWL ranged from 46% to 56%, whereas NRRs of single RIRS ranged from 75% to 93%. Introducing RIRS early in the treatment sequence was observed to be favorable for the reduction of overall failure (overall NRR, 0.997) compared to the results of repeated SWL (overall NRR, 0.928). The implementation of decision tree modeling revealed that the cost per retreatment-avoided increased with the introduction of RIRS at an earlier time (first line, second line, third line, fourth line: 18640 USD, 10376 USD, 4294 USD, 3377 USD, respectively). Probabilistic modeling also indicated that the introduction of RIRS as the first line of treatment was least likely to be cost-effective, when compared to other options of introducing RIRS as the second, third, or fourth line of treatment.

CONCLUSION

Performing RIRS as early as possible can be recommended for eligible patients to reduce the overall failure, even if it is not as cost-effective as performing RIRS later.

Does the presence or degree of hydronephrosis affect the stone disintegration efficacy of extracorporeal shock wave lithotripsy? A systematic review and meta-analysis

The aim of this study was to determine whether the presence or degree of hydronephrosis (HN) affects the stone disintegration efficacy of shock wave lithotripsy (SWL). A comprehensive literature search using PubMed, Embase, Cochrane Library, and Web of Science was conducted to retrieve relevant studies. Risk ratios (RRs) and mean differences (MDs) with corresponding 95% confidence intervals (CIs) were calculated for comparisons of outcomes of interest. In total, seven comparative studies with 2033 patients were included. Overall results indicated no significant difference in stone-free rate (SFR) and retreatment rate between two groups. Subgroup analysis further revealed: (1) compared with moderate or severe HN, non-HN SWL brought significantly lower retreatment rate (RR 0.67, 95%CI 0.52-0.87, P = 0.002 and RR 0.55, 95%CI: 0.40-0.76, P = 0.0003, respectively) and shorter clearance time (MD - 3.80, 95%CI - 5.81 to - 1.79, P = 0.0002 and MD - 5.93, 95%CI - 10.29 to - 1.57, P = 0.008, respectively); (2) SWLs performed without stone-induced HN or with artificial HN were associated with significantly higher SFR (RR 1.11, 95%CI 1.04-1.18, P = 0.001 and RR 0.93, 95%CI 0.87-0.99, P = 0.02, respectively); (3) non-HN SWL brought significantly higher SFR than HN group when treating proximal ureteral stones (RR 1.14, 95%CI 1.04-1.24, P = 0.005). Generally, SWLs performed with HN were shown to offer similar stone disintegration efficacy to those without HN. However, it seemed preferable to perform SWL: (1) without severe to moderate HN or stone-induced HN; (2) with artificial HN; (3) without HN when treating proximal ureteral stones.

Traditional Chinese medicine on treating ureteral calculi: A systematic review and meta-analysis protocol

BACKGROUND

Ureteral calculi generally refer to the temporary obstruction of the human body after the ureteral stenosis. When the ureteral stones are not discharged in time, they can grow in the original site, causing the patient to have corresponding clinical manifestations, such as: renal colic, hematuria, etc, when severe, can cause renal obstruction and hydronephrosis, seriously endangering the patient's health. Ureteral calculi usually occur in young and middle-aged people. The peak age of the disease is between 20 and 50 years old. It also occurs in the young and middle-aged labor force. The men incidence rate is 2 to 3 times that of women. Ureteral calculi is one of the current refractory diseases, and the effect after treatment with integrated Chinese and Western medicine is remarkable.

METHODS AND ANALYSIS

We will search for PubMed, Cochrane Library, AMED, EMbase, WorldSciNet; Nature, Science online and China Journal Full-text Database (CNKI), China Biomedical Literature CD-ROM Database (CBM), and related randomized controlled trials included in the China Resources Database. The time is limited from the construction of the library to November 2018. We will use the criteria provided by Cochrane 5.1.0 for quality assessment and risk assessment of the included studies, and use the Revman 5.3 and Stata13.0 software for meta-analysis of the effectiveness, recurrence rate, and symptom scores of ureteral.

ETHICS AND DISSEMINATION

This systematic review will evaluate the efficacy and safety of Traditional Chinese medicine for ureteral. Because all of the data used in this systematic review and meta-analysis has been published, this review does not require ethical approval. Furthermore, all data will be analyzed anonymously during the review process Trial.Registration number: PROSPERO CRD42019137095.

Predictors of Uric Acid Stones: Mean Stone Density, Stone Heterogeneity Index, and Variation Coefficient of Stone Density by Single-Energy Non-Contrast Computed Tomography and Urinary pH

We analyzed the capacities of pertinent parameters (determined by single-energy non-contrast computed tomography [NCCT]) and urinary pH to predict uric acid stones. We reviewed the medical records of 501 patients whose stones were removed surgically or passed spontaneously between December 2014 and April 2016. Qualifying participants (n = 420) were stratified by the nature of the stone (calcium oxalate, uric acid, or infectious). Based on NCCT, we determined maximal stone length (MSL), mean stone density (MSD), and stone heterogeneity index (SHI) using Hounsfield units (HU) and calculated the variant coefficient of stone density (VCSD = SHI/MSD × 100). Urinary pH was also ascertained. Mean patient age was 55.55 ± 15.46 years. MSD (448.59 ± 173.21 HU), SHI (100.81 ± 77.37 HU), and VCSD (22.58 ± 10.55) proved to be significantly lower in uric acid versus other types of stones, as did urinary pH (5.33 ± 0.56; all p < 0.001). Receiver operating characteristic (ROC) curves depicting predictability of uric acid stones yielded area under ROC curve (AUC) values for MSD, SHI, VCSD, and urinary pH of 0.806 (95% CI: 0.761⁻0.850), 0.893 (95% CI: 0.855⁻0.931), 0.782 (95% CI: 0.726⁻0.839), and 0.797 (95% CI: 0.749⁻0.846), respectively, with corresponding cutpoints of 572.3 HU, 140.4 HU, 25.79, and 6.0. Among these four parameters, SHI was verifiably (DeLong's test) the most effective predictor of uric acid stones (all p < 0.001). Compared with MSD, VCSD, and urinary pH, SHI may better predict uric acid stones, using a cutpoint of 140.4 HU.

Indications and contraindications for shock wave lithotripsy and how to improve outcomes

For over 35 years shock wave lithotripsy has proven to be an effective, safe and truly minimally invasive option for the treatment of nephrolithiasis. Various technical factors as well as patient selection can impact the success of the procedure. We used published work focusing on outcomes of shock wave lithotripsy, risk of complications, and strategies for improving stone fragmentation to create this review. Multiple patient and technical factors have been found to impact success of treatment. Skin to stone distance, stone density and composition, size and location of the stone within the urinary system all influence stone free rates. A slower rate with a gradual increasing voltage, precise targeting, proper coupling will improve stone fragmentation and decrease risk of complications. The selection of appropriate patients through a shared decision making process and attention to the technical factors that improve stone free rates is key to providing an effective treatment and patient satisfaction.

Single extracorporeal shock-wave lithotripsy for proximal ureter stones: Can CT texture analysis technique help predict the therapeutic effect?

PURPOSE

To explore whether the computed tomography texture analysis (CTTA) technique can help predict the curative effects of a single extracorporeal shock-wave lithotripsy (ESWL) for proximal ureteral stones.

MATERIALS AND METHODS

In all, 100 patients with proximal ureteral stone underwent non-enhanced multi-detector computed tomography (MDCT) before ESWL. The patients were divided into success and failure groups. Success of ESWL was defined as the patients being stone-free or having residual stone fragments of ≤2 mm. Traditional characteristics, such as stone size, body mass index (BMI), and skin-to-stone distance (SSD), and CTTA metrics, such as the mean Hounsfield unit (HU) density, entropy, kurtosis, and skewness, were analyzed and compared between two groups by univariate and multivariate logistic regression analyses. Receiver operating characteristic (ROC) curves were generated to determine Youden index-based cutoff values.

RESULT

Failure of stone removal was observed in 36 patients (36%). Stone height, stone cross-sectional diameter, largest cross-sectional area, stone volume, stone density (mean HU), and CTTA metrics (kurtosis and entropy) were the significant independent predictors of ESWL success on univariate analysis (p < 0.05). On multivariate analysis, mean HU, skewness, and kurtosis were shown to be significant predictors of ESWL success (p < 0.05). In subgroup analysis based on the cutoff value of mean stone density (HU = 857), the only significant independent factor associated with both subgroups was kurtosis (p < 0.05).

CONCLUSIONS

As a quantitative analysis method, CTTA may be helpful in selecting appropriate ESWL patients. High kurtosis and low mean HU values simultaneously indicate a relatively higher ESWL success rate.

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.

Digital Videoscopic Retrograde Intrarenal Surgeries for Renal Stones: Time-to-Maximal Stone Length Ratio Analysis

PURPOSE

To investigate 100 consecutive cases of videoscopic retrograde intrarenal surgery (RIRS) by a single surgeon and to evaluate factors associated with stone-free status and the learning curve thereof.

MATERIALS AND METHODS

We analyzed the results of videoscopic RIRS in 100 patients who underwent primary treatment for renal stones from January 2015 to August 2016. Videoscopic RIRS were performed with URF-V and URF-V2 flexible video uteroscopes (Olympus) or a Flex-Xc flexible ureterorenoscope (KARL STORZ). Non-contrast computed tomography was taken at 3 months postoperatively to confirm the absence of stones. The stone characteristics included the location, maximal stone length (MSL), stone heterogeneity index (SHI), and mean stone density (MSD). Fragmentation efficacy was calculated as operative time (min) divided by removed MSL (mm), and was evaluated in the sequential order of operations.

RESULTS

The mean age of the total patient was 60.0±14.0 years. The mean MSL was 13.1±6.2 mm. The average MSD was 734.2±327.6 Hounsfield unit (HU) and the SHI was 241.0±120.0 HU. The mean operation time was 65.1±45.7 min considering each renal unit. The stone-free rate at 3 months post-surgery was 87%. The estimated cut-off of the time-to-MSL ratio below 5 min/mm was 50. Multivariate analyses indicated a lower MSD [odds ratio (OR): 0.998; 95% confidence interval (CI): 0.996-0.999; p=0.047) and the last 50 cases (OR: 5.408, 95% CI: 1.337-30.426; p=0.030) as independent predictors of stone-free status after videoscopic RIRS.

CONCLUSION

Low MSDs and the last 50 cases were significant predictors of stone-free rate in videoscopic RIRS.

Systematic review and meta-analysis to compare success rates of retrograde intrarenal surgery versus percutaneous nephrolithotomy for renal stones >2 cm: An update

BACKGROUND

We performed a systematic review and meta-analysis comparing stone-free rates between retrograde intrarenal surgery (RIRS) and percutaneous nephrolithotomy (PCNL), using updated, more reliable evidence.

MATERIALS AND METHODS

Randomized controlled trials comparing RIRS and PCNL for >2 cm stones were identified from electronic databases. Stone-free rates for the procedures were compared by qualitative and quantitative syntheses (meta-analyses). Outcome variables are shown as risk ratios (RRs) with 95% confidence intervals (CIs).

RESULTS

Eleven articles were included in this study. Most recently published studies exhibited relatively low quality during quality assessment. For the meta-analysis comparing success (stone-free) rates between PCNL and RIRS, the forest plot using the random-effects model showed an RR of 1.11 (95% CI 1.02-1.21, P < .014) favoring PCNL. After determining the among-study heterogeneity, subgroup analysis was performed of 9 studies with less heterogeneity: the stone-free rate of PCNL was superior to that of RIRS using a fixed-effect model (RR 1.07, 95% CI 1.01-1.14, P < .019) for these studies.

CONCLUSIONS

RIRS can be a safe and effective procedure for selected patients with large renal stones. However, in this meta-analysis, the postoperative stone-free rate of PCNL was higher than that of RIRS in patients with >2 cm renal stones.