Extracorporeal Shock Wave Therapy: Current Perspectives and Future Directions

The efficacy of early extracorporeal shockwave lithotripsy for the treatment of 5 to 10 mm upper ureteral stones: An observational study

This study aimed to determine the effectiveness of extracorporeal shockwave lithotripsy (SWL) performed in the early period (within the first 24 hours). Data of patients who underwent SWL with a diagnosis of unilateral radiopaque 5 to 10 mm upper ureteral stones were retrospectively examined. Patients were divided into 2 groups. Group 1 (early SWL) consisted of patients with SWL performed within 24 hours after the onset of colic pain (<24 hours), while group 2 (deferred SWL) comprised patients with SWL performed 24 hours or more from the onset of pain (≥24 hours). The primary endpoint of the study was planned to determine 1-month SFR in both groups. The secondary endpoint was determined to be the factor affecting SWL success. The mean age of 216 patients (130 men, 86 women) included in this study was 46.5 ± 12.1 years. SFR within 1 month was detected in 175 patients (81%). In the early SWL group, the average number of SWL sessions was fewer (1.26 vs 1.83 P = .026) and the time to the stone-free state was shorter (11 vs 15.4 days P = .044). SFR within 1 month was higher in the early SWL group (85.5% vs 71.8% P = .036). In multivariate analysis, stone size, Hounsfield Units, and early SWL were predictive factors for SWL success. Performing SWL within the first 24 hours is highly effective in patients with symptomatic 5 to 10 mm upper ureteral stones.

Predictive markers for infections after extracorporeal shockwave lithotripsy in patients with kidney stone based on a large prospective cohort

OBJECTIVE

Infections in patients with kidney stones after extracorporeal shockwave lithotripsy (SWL) is a common clinical issue. However, the associated factors are unclear. Therefore, we aim to develop and validate a predictive model for infections after SWL in patients with kidney stone.

METHODS

Between June 2020 and May 2022, consecutive kidney stone patients were enrolled. Of them, 553 patients comprised the development cohort. One hundred sixty-five patients comprised the validation cohort. The data were prospectively collected. The stepwise selection was applied using the likelihood ratio test with Akaike's information criterion as the stopping rule; A predictive model was constructed through multivariate logistic regression. The performance was evaluated regarding discrimination, calibration, and clinical usefulness.

RESULTS

Predictors of infections after SWL in treating kidney stones included older age (OR = 1.026, p = 0.041), female (OR = 2.066, p = 0.039), higher BMI (OR = 1.072, p = 0.039), lower stone density (OR = 0.995, p < 0.001), and higher grade of hydronephrosis (OR = 5.148, p < 0.001). For the validation cohort, the model showed good discrimination with an area under the receiver operating characteristic curve of 0.839 (95% CI 0.736, 0.941) and good calibration. Decision curve analysis demonstrated that the model was also clinically useful.

CONCLUSION

This study indicated that age, gender, BMI, stone density, and hydronephrosis grade were significant predictors of infections after SWL in treating kidney stones. It provided evidence in optimizing prevention and perioperative treatment strategies to reduce the risk of infection after SWL.

Extracorporeal shock wave lithotripsy for lower calyx stones: predicting treatment success

INTRODUCTION

The use of extracorporeal shock wave lithotripsy (ESWL) for lower calyx stones is associated with a high rate of residual fragments. Our aim is to analyse the effectiveness and complications of ESWL for lower calyx stones.

METHODS

Retrospective review of patients with lower renal calyx stones treated with ESWL between January-2014 and December-2020. Measurement of infundibular length, infundibular width and infundibulopelvic angle in lower renal pole to determine favourable anatomy. ESWL failure: fragments >3 mm detected in plain abdominal film, CT scan and/or renal ultrasound 3 months after treatment. Complications after ESWL, auxiliary procedures along with risk factors associated with perirenal haematoma were analysed. SPSS statistical software was used.

RESULTS

512 patients with lower calyx stones were treated with ESWL. 80.3% of patients had a favourable anatomy. Overall stone-free rate was 70.5%. Regarding main complications after ESWL, stainstrasse was described in 5 patients and urinary tract infection in 3 patients. 10 perirenal haematomas (2%) were reported. Statistical association was found between antiplatelet treatment and the risk of perirenal haematoma (p = 0.004). Logistic binary regression proved the association between unfavourable anatomy of the lower renal pole (p = 0.000), size of the stone (p = 0.001), number of shock waves (p = 0.003), energy applied (p = 0.038) and the need for additional treatment after ESWL.

CONCLUSIONS

ESWL can still be considered as the initial treatment option for lower renal pole stones. The size of the stone, an unfavourable anatomy of the lower renal calyx, number of shock waves and energy applied can help predict the need for additional treatment.

The effect of piezoelectric shockwave lithotripsy with 2- and 8-mm focus sizes on stone disintegration and renal injury

OBJECTIVES

To compare the efficacy and safety of shockwave lithotripsy (SWL) using a narrow focus or wide focus for renal stones.

PATIENTS AND METHODS

A double-blind randomised trial included adult patients with a solitary radio-opaque renal pelvic stone of 1-2 cm. Patients were randomised into two groups: narrow-focus (2 mm) SWL and wide-focus (8 mm) SWL. The stone-free rate (SFR) and presence of complications such as haematuria, fever, pain, and peri-renal haematoma were evaluated. Pre- and postoperative urinary markers (neutrophil gelatinase-associated lipocalin [NGAL] and kidney injury molecule 1 [KIM-1]) concentrations were compared to assess renal injury.

RESULTS

A total of 135 patients were recruited for this study. The SFR after the first SWL session was 79.2% and 69.1% in narrow- and wide-focus groups, respectively. There was a comparable rise in the median 2-h NGAL concentration in both groups (P = 0.62). However, the rise in the median (interquartile range [IQR]) 2-h KIM-1 concentration was significantly higher in the narrow-focus group at 4.9 (4.6, 5.8) ng/mL compared with the wide-focus group at 4.4 (3.2, 5.7) ng/mL (P = 0.02). Nevertheless, the 3-day NGAL and KIM-1 urinary marker concentrations were significantly improved (P = 0.263 and P = 0.963, respectively). The overall SFR after three sessions was 86.6% and 86.8% in the narrow- and wide-focus groups, respectively (P = 0.77). Both groups were comparable for complications, apart from the median pain score and the percentage of high-grade haematuria, which were significantly higher in the narrow-focus group (P < 0.001 and P = 0.03, respectively).

CONCLUSION

Narrow- and wide-focus SWL were associated with comparable outcomes and re-treatment rates. However, narrow-focus SWL was associated with significantly higher morbidity in terms of pain and haematuria.

Prospective comparison of extracorporeal shock wave lithotripsy and ureteroscopy in distal ureteral stones

The optimal treatment modality of distal ureteral stones is controversial. Therefore, we conducted a prospective study to evaluate the efficacy, safety, and cost of early second shock wave lithotripsy (SWL) sessions versus ureterorenoscopy (URS) in patients with distal ureteral stones. This prospective study was conducted in a tertiary hospital from June 2020 to April 2022. Patients who underwent SWL or URS for distal ureteral stones were enrolled in this study. The stone-free rate (SFR), secondary treatment rate, complications, and costs were recorded. Propensity-score matching (PSM) analysis was also performed. A total of 1023 patients were included, of whom 68.4% (700) were treated with SWL and 31.6% (323) with URS. Based on PSM, SWL had an equivalent SFR (87.4% vs. 84.9%, P = 0.325) at one month after SWL and secondary treatment rate (10.7% vs.10.8%, P = 0.958) when compared with URS. Complications were rare and comparable between the SWL and URS groups (6.0% vs. 5.9%, P > 0.05), while the incidence of ureteral injuries (i.e., perforations) was higher in the URS group compared with the SWL group (1.3% vs. 0%, P = 0.019). The hospital stay was significantly shorter (1 day vs. 2 days, P < 0.001) and the costs considerably less (2000 RMB vs. 25,030 RMB; P < 0.001) in the SWL group compared with the URS group. This prospective study demonstrated that early second SWL sessions had equivalent efficacy in addition to reduced complication rates and costs compared with URS in patients with distal ureteral stones. Our findings may help guide clinical decision making.

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.

Bowel Perforation after Extracorporeal Wave Lithotripsy: A Review of the Literature

INTRODUCTION

Extracorporeal wave lithotripsy (ESWL) is considered a first-line treatment for renal and ureteral stones up to 10-20 mm in diameter. Complications are uncommon, with a reported rate of 0-6% in the literature. Bowel perforation has only been described in a few case reports but requires rapid diagnosis and treatment.

METHODS

A review of the literature from PubMed/Medline, Embase, Cochrane, and Web of Science databases was performed including studies reporting bowel perforation secondary to ESWL between January 1990 and June 2022.

RESULTS

We found 16 case reports of intestinal perforation in the literature. Although some patients had previously undergone abdominal surgery or had inflammatory intestinal disease, others were without comorbidities that could lead to complications. Abdominal pain was the main symptom and imaging was required to confirm the diagnosis, which usually necessitated a surgical intervention. As regards the ESWL technique, it appears that the combination of a high energy level and the prone position constitutes a risk factor for these rare complications. At the authors' centre, only one case has been reported among 24,000 ESWL procedures over 20 years: A 59-year-old female who underwent ESWL for a distal right ureteral stone presented acute abdominal pain and free intraperitoneal pelvic fluid on ultrasound. A CT scan revealed a small bowel perforation requiring open laparotomy with primary closure.

CONCLUSIONS

In conclusion, although bowel perforation after ESWL is rare, progressive abdominal pain with tenderness at physical examination requires proper imaging evaluation to exclude bowel perforation and prompt intervention if required.

Molecular Mechanisms Underlying the Pain-Relieving Effects of Extracorporeal Shock Wave Therapy: A Focus on Fascia Nociceptors

In recent years, extracorporeal shock wave therapy (ESWT) has received increasing attention for its potential beneficial effects on various bone and soft-tissue pathologies, yielding promising outcomes for pain relief and functional recovery. In fact, ESWT has emerged as an alternative, non-invasive, and safe treatment for the management of numerous musculoskeletal disorders, including myofascial pain syndrome (MPS). In particular, MPS is a common chronic painful condition, accounting for the largest proportion of patients affected by musculoskeletal problems. Remarkably, sensory innervation and nociceptors of the fascial system are emerging to play a pivotal role as pain generators in MPS. At the same time, increasing evidence demonstrates that application of ESWT results in selective loss of sensory unmyelinated nerve fibers, thereby inducing long-lasting analgesia. The findings discussed in the present review are supposed to add novel viewpoints that may further enrich our knowledge on the complex interactions occurring between disorders of the deep fascia including changes in innervation, sensitization of fascial nociceptors, the pathophysiology of chronic musculoskeletal pain of MPS, and EWST-induced analgesia. Moreover, gaining mechanistic insights into the molecular mechanisms of pain-alleviating effects of ESWT may broaden the fields of shock waves clinical practice far beyond the musculoskeletal system or its original application for lithotripsy.

A clinical observational study of effectiveness of a solid coupling medium in extracorporeal shock wave lithotripsy

This study aimed to investigate clinical effectiveness of stone disintegration by using isolation coupling pad (“icPad”) as coupling medium to reduce trapped air pockets during extracorporeal shock wave lithotripsy (ESWL). Patients underwent ESWL between Oct. 2017 and May 2018 were enrolled in this clinical observational study. An electromagnetic lithotripter (Dornier MedTech Europe GmbH Co., Germany) was used in this study. Patients were divided into icPad group P1, P2 and semi-gel group C by different coupling medium. The energy level and total number of shock wave (SW) for group P1 and C was set at level 2 and 3000 and group P2 at level 3 and 2500. The successful stone disintegration rate (SSDR) was determined to evaluate the treatment outcome. All patients were evaluated by KUB film and ultrasonography after 90 days. Complications during ESWL were recorded. A total of 300 patients satisfied the inclusion criteria. There were no significant differences in characteristics of patients and stone among three groups. The corresponding SSDRs for patients in group P1, P2 and C was 73.0%, 73.2% and 55.3%, respectively. The SSDR in group P1 was statistically higher than Group C. Comparing to semi-liquid gel, coupling medium using by icPad could achieve better treatment outcome of stone disintegration in ESWL.

Prognostic factors for the safety and efficacy of retrograde laser lithotripsy: Data from a contemporary series of 155 consecutive patients with single and multiple lithiasis of the urinary tract

Treatment of large and multiple stones located in the ureter and/or the kidney may be challenging. The aim of the current study was to evaluate the results and complications of retrograde endoscopic lithotripsy for stones located in the urinary tract and to determine prognostic factors for treatment outcome. From April 2017 to March 2020, eligible patients for the active treatment of ureterolithiasis with or without concomitant nephrolithiasis <20 mm were enrolled in the study. The prognostic factors for the stone free rate (SFR) after the 1st and subsequent sessions and overall complications were assessed. Patients were divided into single or multiple lithiasis groups (groups A and B respectively). A comparison between these two groups was then conducted. Overall, 237 stones were detected in 155 patients, representing a mean burden of 1.53 stone per patient. The mean total stone size was 14.7 mm, the initial SFR was 80% and the final SFR (after a mean of 1.23 session per patient) was 94.2%. The rate of complications was 26.4%. Multivariative analysis revealed that preoperative stenting and total stone size were independent prognostic factors of initial SFR, while no independent factors were determined for final SFR. Age, total size and stones in the lower calyx were independent factors for complications. In group A and B, 114 and 41 cases with solitary and multiple stones were included, respectively. Excluding operation time (P=0.002), no significant differences were recorded in terms of initial (P=0.255) and final SFR (P=0.056), hospital stay (P=0.308), mean number of treatments (P=0.757) and the rate of complications (P=0.218) between the two groups. In conclusion, retrograde endoscopic management of multiple lithiasis has a favorable outcome irrespective of stone location. Older patients with higher burdens and stones in the lower calyx should be treated with caution.

Shock wave and mesenchymal stem cells as treatment in the acute phase of spinal cord injury: A pilot study

INTRODUCTION

Spinal cord injury (SCI) is a complex pathology with thousands of patients worldwide. During the acute early phase, neural tissue shows some regenerative properties that disappear at the chronic phase. Shock Waves and Stem Cells have been proposed as a possible therapy.

METHODS

Here, we analyse Shock Waves' immediate effect over spinal cord genetic response in the injured and healthy spinal cord and the effect of Shock Waves and combined Shock Waves plus Stem Cells distally grafted to treat the first month after spinal cord injury.

RESULTS

The immediate application of shock waves increases VEGF (Vascular Endothelial Growth Factor) but reduces the BDNF (Brain-Derived Growth Factor) RNA (Ribonucleic acid) response. Shock wave therapy increases GFAP (Glial fibrillary acidic protein) positive cells and vascularity during the treatment's acute phase.

CONCLUSION

Shock wave treatment seems to be enough to produce benefits in the acute phase of spinal cord injury, with no accumulative positive effects when mesenchymal stem cell graft is applied together.

Multiphysics Analysis of Ultrasonic Shock Wave Lithotripsy and Side Effects on Surrounding Tissues

Background:

Today, the most common method for kidney stone therapy is extracorporeal shock wave lithotripsy. Current research is a numerical simulation of kidney stone fragmentation via ultrasonic shock waves. Most numerical studies in lithotripsy have been carried out using the elasticity or energy method and neglected the dissipation phenomenon. In the current study, it is solved by not only the linear acoustics equation, but also the Westervelt acoustics equation which nonlinearity and dissipation are involved.

Objective:

This study is to compare two methods for simulation of shock wave lithotripsy, clarifying the effect of shock wave profiles and stones’ material, and investigating side effects on surrounding tissues

Material and Methods:

Computational study is done using COMSOL Multiphysics, commercial software based on the finite element method. Nonlinear governing equations of acoustics, elasticity and bioheat-transfer are coupled and solved.

Results:

A decrease in the rise time of shock wave leads to increase the produced acoustic pressure and enlarge focus region. The shock wave damages kidney tissues in both linear and nonlinear simulation but the damage due to high temperature is very negligible compared to the High Intensity Focused Ultrasound (HIFU).

Conclusion:

Disaffiliation of wave nonlinearity causes a high incompatibility with reality. Stone’s material is an important factor, affecting the fragmentation

Efficacy of Unfocused Medium-Intensity Extracorporeal Shock Wave Therapy (MI-ESWT) for Plantar Fasciitis

Extracorporeal shock wave therapy (ESWT) is a promising treatment for plantar fasciitis (PF), however, treatment results have varied due to inconsistencies among types of shock wave treatment and devices used. This retrospective chart review includes patients who underwent ESWT using the OrthoGold 100™ shock wave device (MTS, Konstanz, Germany) for PF between January, 2013 and September, 2018. There were 108 patients (119 heels) identified, with a mean age of 51.7 ± 16.5 (Range 21-83) years. Patients were treated weekly for 3 weeks, with 2000 impulses per session at an energy flux density between 0.10 and 0.17 mJ/mm². Mean follow-up duration was 11.5 ± 9.7 (Range 3-51) months. Mean pre-ESWT pain visual assessment scale improved from 6.7 ± 1.7 to 2.6 ± 2.7 (p < .001). The Foot and Ankle Outcome Score subscales: pain, function of daily living, function of sports and recreational activities and quality of life domains improved from 53.7 ± 14.9 to 75.7 ± 16.7 (p < .001), from 38 ± 15.2 to 71.8 ± 23 (p < .001), from 55.8 ± 16.4 to 71.4 ± 18 (p < .001), from 42.4 ± 21.5 to 59.4 ± 20.3 (p < .001) and from 44.9 ± 16.4 to 69 ± 23.9 (p < .001), respectively. Eighty-eight (81.5%) patients were satisfied with the procedure at final follow-up. Treatment of PF with unfocused shock waves was well tolerated and led to significant pain reduction, functional improvement, and patient satisfaction.

Newly designed solid coupling medium for reducing trapped air pockets during extracorporeal shock wave lithotripsy_ a phantom study

INTRODUCTION

Air pockets between the lithotripter head and body surface are almost inevitably generated when applying a handful of gel onto the contact portion of the treatment head and that on the patient's skin during coupling procedure. These air pockets can compromise the transmission of acoustic energy of shock wave and may significantly affect efficacy of stone disintegration. Comparing to conventional gel, this study aims to investigate efficacy of stone disintegration by using a proprietary isolation-coupling pad ("icPad") as the coupling medium to reduce trapped air pockets during ESWL procedure.

METHOD

In this phantom study, Dornier lithotripter (Delta-2 RC, Dornier MedTech Europe GmbH Co., Germany) was used with a proprietary gel pads (icPad, Diameter = 150 mm, Thickness = 4 mm and 8 mm). The lithotripter was equipped with inline camera to observe the trapped air pockets between the contact surface of the lithotripter head. A testing and measuring device were used to observe experimental stone disintegration using icPad and semi-liquid gel. The conventional semi-liquid gel was used as control for result comparison.

RESULTS

The stone disintegration rate of icPad 4 mm and 8 mm after 200 shocks of energy at level 2 were significantly higher than that of the semi-liquid gel (disintegration rate 92.3%, 85.0% vs. 45.5%, respectively, p < 0.001). The number of shocks for complete stone disintegration by icPad of 4 mm and 8 mm at the same energy level 2 were significantly lower than that of the semi-liquid gel (the number of shocks 242.0 ± 13.8, 248.7 ± 6.3 vs. 351.0 ± 54.6, respectively, p = 0.011). Furthermore, quantitative comparison of observed air pockets under Optical Coupling Control (OCC) system showed that the area of air pockets in semi-liquid group was significantly larger than that of the group using icPad (8 mm) and that of the group using icPad (8 mm) after sliding (332.7 ± 91.2 vs. 50.3 ± 31.9, 120.3 ± 21.5, respectively, p < 0.05).

CONCLUSION

The advantages of icPad includes: (1) reduced the numbers of shock wave and increased stone disintegration rate due to icPad's superior efficacy; (2) significantly reduce trapped air pockets in ESWL coupling. Due to the study limitation, more data are needed to confirm our observations before human trials.

Structure Types of Kidney Stones and Their Susceptibility to Shock Wave Fragmentation

Background:

The modern approach in the treatment of urolithiasis involves the use of non-invasive and minimally invasive techniques based on the stone fragmentation, among which shock wave lithotripsy (SWL) is considered as the first-line treatment for kidney stones < 2 cm and proximal ureter stones.

Objective:

To study the microstructure and mineral composition of kidney stones and to evaluate their influence on the stones’ susceptibility to fragmentation by shock waves.

Methods:

The microstructure and mineral composition of kidney stone samples obtained from shock wave lithotripsy in 87 patients were studied using crystal optical analysis and infrared spectroscopy. The volume fraction of amorphous and crystalline phases of the stone composition, the quantitative and qualitative composition of mineral components were assessed. The fragmentation features of stones with different microstructure were retrospectively analyzed based on the total number of shock waves required for complete stone fragmentation.

Results:

Three kidney stone structure types were identified: amorphous-crystalline structure stones predominantly including the amorphous phase (type A); amorphous-crystalline structure stones predominantly including the crystalline phase (type B); fully crystalline structure stones (type C). Significant positive correlation between the total number of shock waves required for complete stone fragmentation and the volume fraction of crystalline phase was found.

Conclusion:

The structure type of kidney stones is determined by the volume ratio between the amorphous and crystalline phases of their composition. The amorphous-crystalline structure stones with the predominant content of the amorphous phase are more sensitive to shock-wave exposure. The increase in the volume fraction of crystalline phase in the stone structure reduces the stone’s susceptibility to fragmentation by shock waves.

Association between physical activity and kidney stones based on dose-response analyses using restricted cubic splines

BACKGROUND

This study aimed to determine whether there is a dose-response relationship between physical activity and the self-reported prevalence of kidney stone, based on a restricted cubic splines (RCS) method.

METHODS

This study analyzed 8931 adults aged ≥20 years who had participated in the National Health and Nutrition Examination Survey (NHANES) during 2013-16. Kidney stones and physical activity were defined using a standard questionnaire, and metabolic equivalents (MET) were used to quantify the physical activity level. Logistic regression was used to assess the association between physical activity and the risk of kidney stones, and the dose-response relationship was explored using RCS.

RESULTS

Kidney stones were present in 10.3% of the analyzed individuals: 11.5% of males and 9.2% of females. After adjusting for potential confounders, compared with the first quartile (Q1) of MET, the odds ratios (ORs) of kidney stones for those with Q2, Q3 and Q4 of MET were 0.72 [95% confidence interval (CI)=0.59-0.87], 0.77 (95% CI = 0.63-0.93) and 0.63 (95% CI = 0.51-0.78), respectively (all P < 0.01). The RCS regression showed that physical activity was related to kidney stones in a non-linear manner (P for non-linearity = 0.0100). The prevalence of kidney stones decreasing as physical activity increased, reaching a plateau for physical activity at approximately 2480 MET-min week-1 (OR = 0.75, 95% CI = 0.63-0.91).

CONCLUSIONS

Physical activity is inversely associated with the prevalence of kidney stones, and the dose-response relationship has a plateau, after which the prevalence of kidney stones does not change with the increase of physical activity.

Prediction of stone-free rates following extracorporeal shockwave lithotripsy in a contemporary cohort of patients with stone densities exceeding 1000 HU

Purpose: Nephrolithiasis is a common urologic problem, and its incidence is increasing. Shockwave Lithotripsy (SWL) has better results for patients with stones < 1000 HU. We attempted to identify SWL stone-free (SF) predictors for > 1000 HU stones.Methods: From January 2013 to September 2019, patient shared decision consecutive SWL for the treatment of a single > 1000 HU renal stone diagnosed by non-contrast computed tomography (NCCT). Endpoints: Fragmentation and SF or clinically insignificant residual fragments ≤ 4 mm at 4 weeks. Age, gender, stone side, location, size and density, number and average energy (Joules) of shocks were explored on uni- and multivariate regression analysis.Results: All sixty-one patients included were diagnosed with renal stone between 5 and 20 mm (maximum length) and underwent one SWL session only: 62.3% males, median age 48 (21-80) years, mean stone size 9.43 ± 2.9 mm (6.0-20.0), mean density 1210 ± 135 HU (1000-1558). There were 39 (63.9%) cases of SF, 16 (26.2%) of partial success and six (9.8%) of no success. Stone size was the only independent predictor of fragmentation, OR = 1.83, 95% CI = 1.32-2.55, p = 0.0003, and SF OR = 1.91, 95% CI = 1.31-2.78, p = 0.008. The best discriminatory stone size on ROC analysis was 1 cm.Conclusion: Stone size was the only significant success predictor in our cohort, with 76% SF rate for stones < 1 cm in 4 weeks follow-up, supporting that renal stones > 1000 HU may be suitable to SWL.

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.

Factors affecting success in the treatment of proximal ureteral stones larger than 1 cm with extracorporeal shockwave lithotripsy in adult patients

The aim of the study was to analyze the factors predicting success for the treatment of proximal ureteral stones larger than 1 cm with extracorporeal shockwave lithotripsy (SWL) in adult patients. Between January 2014 and December 2018, 480 adult patients in total underwent SWL and data were retrospectively evaluated. Patients with multiple ureteral stones, solitary kidney, congenital abnormality, skeletal system abnormality, history of previous urinary system surgery and SWL, renal insufficiency, patients who could not tolerate SWL and pediatric patients were excluded from the study. The remaining 415 patients were divided into two groups as success (Group 1, n = 307) and failure (Group 2, n = 108). The overall success rate was 73.9%. The values of stone size, Hounsfield Unit (HU), skin to stone distance (SSD), ureteral wall thickness (UWT), proximal ureter diameter, renal pelvis diameter, hydronephrosis grade, and duration of renal colic were significantly higher in Group 2 compared to Group 1. In binary logistic regression analyses, HU, UWT, and proximal ureter diameter were found to be independent predictors. HU, UWT, and proximal ureter diameter had sensitivity and specificity of 92-92%, 88-23%, and 87-46%, with cutoff values of 740 HU, 2.5 mm and 8.5 mm, respectively. The area under the curve values were 0.96, 0.97, and 0.96 for HU, UWT, and proximal ureter diameter, respectively. The CT-based parameters, including HU, UWT, and proximal ureter diameter are independent predictive factors with excellent accuracy for the treatment of proximal ureteral stones larger than 1 cm with SWL in adult patients. Based on these factors, SWL can be considered for proximal ureteral stones larger than 1 cm.

The role of extracorporeal shock wave lithotripsy in the future of stone management

PURPOSE OF REVIEW

The most relevant recent findings on the use of extracorporeal shock wave lithotripsy (ESWL) in adult population to provide an insight of its role in the current and future of stone treatment. Comparing ESWL with other modalities is not in the scope of this review.

RECENT FINDINGS

We conducted a PubMed/Embase search and reviewed recent publications that include relevant information on the development of ESWL. Low-rate shock waves improve stone breakage, ramping energy modalities improve stone fragmentation and have lower incidence of hematoma and kidney injury. Transgluteal approach is suggested to improve stone-free rates for distal ureteral stones in a single session. Proper coupling is the most important technical aspect of the treatment and coupling improvement can be achieved by optical monitorization. Triple D score is a promising tool in proper patient selection, but external validation is needed. Predictive information arising from computed tomography scans has been refined by the variant coefficient of stone density and 3D texture analysis that might improve outcomes in the future.

SUMMARY

Recent evidence suggests that modifying techniques and protocols, and better patient selection are the current trends for improving ESWL outcomes. EWSL will keep its role as the single noninvasive treatment in stone management with room for outcome improvement in the future.

Comparison of stone-free rates following shock wave lithotripsy, percutaneous nephrolithotomy, and retrograde intrarenal surgery for treatment of renal stones: A systematic review and network meta-analysis

OBJECTIVES

To perform a systematic review and network meta-analysis comparing stone-free rates following retrograde intrarenal surgery (RIRS), extracorporeal shock wave lithotripsy (SWL), and percutaneous nephrolithotomy (PCNL) treatments of renal stones.

MATERIALS AND METHODS

Clinical trials comparing RIRS, SWL, and PCNL for treatment of renal 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 (ORs) with 95% credible intervals (CIs).

RESULTS

A total of 35 studies were included in this network meta-analysis of success and stone-free rates following three different treatments of renal stones. Six studies compared PCNL versus SWL, ten studies compared PCNL versus RIRS, fourteen studies compared RIRS versus SWL, and five studies compared PCNL, SWL, and RIRS. The quality scores within subscales were relatively low-risk. Network meta-analyses indicated that stone-free rates of RIRS (OR 0.38; 95% CI 0.22-0.64) and SWL (OR 0.12; 95% CI 0.067-0.19) were lower than that of PCNL. In addition, stone-free rate of SWL was lower than that of RIRS (OR 0.31; 95% CI 0.20-0.47). Stone free rate of PCNL was also superior to RIRS in subgroup analyses including ≥ 2 cm stone (OR 4.680; 95% CI 2.873-8.106), lower pole stone (OR 1.984; 95% CI 1.043-2.849), and randomized studies (OR 2.219; 95% CI 1.348-4.009). In rank-probability test, PCNL was ranked as No. 1 and SWL was ranked as No. 3.

CONCLUSIONS

PCNL showed the highest success and stone-free rate in the surgical treatment of renal stones. In contrast, SWL had the lowest success and stone-free rate.

Trends in the treatment of urinary stone disease in Turkey

Introduction

In this study, a survey was prepared for urologists that asked about their primary choice of treatment for urolithiasis in daily practice and their answers were evaluated.

Methods

The survey was prepared on the Google Docs website and it was sent to 1,016 urologists via email with 752 confirmed deliveries. In addition to the demographic questions about each participant's age, gender, and institution, the survey presented case scenarios focusing on their preferred treatment modalities for distal ureteric, proximal ureteric, and renal calculi. The participating urologists were divided into two groups according to the frequency that they treat urolithiasis patients.

Results

Of the 752 surveys delivered, 211 urologists (28.05%) responded and 204 answered all questions. According to the results, there were no significant differences between the treatment approaches and the other localizations, but there was a statistically significant difference for treatment approaches to lower pole stones between two groups. In response to the question of which stone treatment method was used less frequently, 124 (60.7%) participants answered that they used shock wave lithotripsy less in the last 10 years.

Conclusion

The present study has shown that while the management of renal and ureteric calculi by Turkish urologists is highly varied, the overall treatment patterns are in accordance with the European Association of Urology guidelines. However, similar to the global trend extracorporeal shock wave lithotripsy is less preferred by Turkish urologists.