Current state and future developments of noninvasive treatment of human urinary stones with extracorporeal shock wave lithotripsy

Prospective Evaluation of Extracorporeal Shockwave Lithotripsy in Renal and Upper Ureteric Stone Treatment: Clinical Assessment and Results

INTRODUCTION

Extracorporeal shockwave lithotripsy (ESWL) is a widely accepted non-invasive treatment for renal and upper ureteric stones smaller than 2 cm due to its safety and efficacy. Despite advancements in minimally invasive techniques, extracorporeal shockwave lithotripsy remains an important modality.

AIMS AND OBJECTIVE

This prospective observational study aimed to evaluate the outcomes of ESWL in managing renal and upper ureteric stones measuring less than 2 cm in terms of stone clearance.

MATERIAL AND METHODS

In a study conducted at a university-affiliated tertiary care hospital, 119 patients with renal and upper ureteric stones underwent extracorporeal shockwave lithotripsy over a 12-month period. Data on patient demographics, stone characteristics, treatment procedures, and complications were collected. Follow-up assessments were performed at two-week intervals for up to two months post-treatment.

RESULTS

The mean age of patients was 39.78 years, with a mean stone size of 1.2 cm. Right kidney stones were more prevalent (61.3% [n=76]). Complications included fever (19.3% [n=23]), gross haematuria (24.3% [n=29]), and steinstrasse (21.8% [n=26]). The success rate of extracorporeal shockwave lithotripsy was 81.5% (n=97), with 18.5% (n=22) of patients requiring surgical intervention due to incomplete fragmentation or residual fragments >4 mm. Stone size and density played significant roles in treatment success.

CONCLUSION

Despite advancements in minimally invasive techniques, ESWL retains its significance as a noninvasive and effective treatment option for renal and upper ureteric stones smaller than 2 cm. Its success depends on various factors, including the stone site, size, and composition. ESWL offers advantages such as minimal morbidity, shorter hospital stays, and better patient compliance. Complications such as steinstrasse are manageable with conservative measures or ancillary procedures. While ESWL may be losing ground in some cases, its noninvasive nature and favourable outcomes make it a valuable option in the armamentarium for stone management.

Unusual complication after shock wave lithotripsy (SWL) for a renal stone: A subcapsular hepatic hematoma. A case report and review of literature

Urolithiasis is a common urological condition that affects around 8 per 1000 people every year. Management depends on multiple factors varying between stone related and patient related factors. In some cases, shock wave lithotripsy (SWL), one of the most popular noninvasive and safe procedures, is required where conservative measures fail. However, it can lead to life-threatening complications. Here we present rare case of hepatic hematoma in a 57-year-old female patient following SWL for right kidney stone on the 2nd day post-SWL. The patient was managed successfully with conservative measures.

International Alliance of Urolithiasis Guideline on Shockwave Lithotripsy

Different international associations have proposed their own guidelines on urolithiasis. However, the focus is primarily on an overview of the principles of urolithiasis management rather than step-by-step technical details for the procedure. The International Alliance of Urolithiasis (IAU) is releasing a series of guidelines on the management of urolithiasis. The current guideline on shockwave lithotripsy (SWL) is the third in the IAU guidelines series and provides a clinical framework for urologists and technicians performing SWL. A total of 49 recommendations are summarized and graded, covering the following aspects: indications and contraindications; preoperative patient evaluation; preoperative medication; prestenting; intraoperative analgesia or anesthesia; intraoperative position; stone localization and monitoring; machine and energy settings; intraoperative lithotripsy strategies; auxiliary therapy following SWL; evaluation of stone clearance; complications; and quality of life. The recommendations, tips, and tricks regarding SWL procedures summarized here provide important and necessary guidance for urologists along with technicians performing SWL. PATIENT SUMMARY: For kidney and urinary stones of less than 20 mm in size, shockwave lithotripsy (SWL) is an approach in which the stone is treated with shockwaves applied to the skin, without the need for surgery. Our recommendations on technical aspects of the procedure provide guidance for urologists and technicians performing SWL.

Single-Center Experience with Swiss LithoClast® Trilogy for Kidney Stones

INTRODUCTION

PCNL remains the gold standard for larger kidney stones. Reducing the operating time of PCNL and its complication rate seems to be the next logical step in optimizing this classical technique. To achieve these objectives, some new methods of lithotripsy emerge. We present the data of a single, high-volume, academic center with combined ultrasonic and ballistic lithotripsy in PCNL using the Swiss LithoClast^® Trilogy device.

MATERIALS AND METHODS

We designed a prospective, randomized study including patients who underwent PCNL or miniPerc with lithotripsy using the new EMS Lithoclast Trilogy or EMS Lithoclast Master. The procedure was carried out with all patients in prone position, by the same surgeon. The working channel size was 24 Fr-15.9 Fr. We evaluated the stones' features, operative time, fragmentation time, complications, stone clearance rate and stone-free rate.

RESULTS

Our study included 59 patients, 38 females and 31 males, of an average age of 54.5 years old. The Trilogy group included 28 patients and the comparator included 31 patients. Urine culture was positive in seven cases which required seven days of antibiotics. The mean stone diameter was 35.6 mm with a mean Hounsfield unit (HU) of 710.1. The average number of stones was 2.08 (6 complete staghorn stones and 12 partial staghorn stones). A total of 13 patients presented a JJ stent (46.4%). We found a very significant difference in all the parameters favoring the Trilogy device. The most important result in our opinion is the probe active time, which was almost six times shorter in the Trilogy group. The stone clearance rate was about double in the Trilogy group, leading to shorter overall and intra-renal operating times. The overall complication rate was 17.9% in the Trilogy group and 23% in the Lithoclast Master group. The mean hemoglobin drop was 2.1 g/dL with a mean creatinine rise of 0.26 mg/dL.

CONCLUSIONS

Swiss LithoClast^® Trilogy, a device combining ultrasonic and ballistic energy, is a safe and efficient method of lithotripsy for PCNL, proving statistically significant benefits over its predecesor. It can achieve the goal of reducing complication rates and operative times for PCNL.

Development and validation of a predictive model for stone-free failure after extracorporeal shockwave lithotripsy in patients with ureteral stone in a large prospective cohort

PURPOSE

To develop and validate a nomogram for predicting stone-free failure after shock wave lithotripsy (SWL) guided by ultrasound in patients with ureteral stones.

METHODS

The development cohort consisted of 1698 patients who underwent SWL guided by ultrasound at our center from June 2020 through August 2021. Multivariate unconditional logistic regression analysis was used for building a predictive nomogram with regression coefficients. An independent validation cohort consisted of 712 consecutive patients from September 2020 through April 2021. The performance of the predictive model was assessed in regard to discrimination, calibration, and clinical usefulness.

RESULTS

Predictors of stone-free failure included distal stone location (odds ratio = 1.540, P < 0.001), larger stone size (odds ratio = 1.722, P < 0.001), higher stone density (odds ratio = 1.722, P < 0.001), larger skin to stone distance (SSD) (odds ratio = 1.058, P < 0.001), and higher grade of hydronephrosis (odds ratio = 1.755, P = 0.010). For the validation cohort, the model showed good discrimination with an area under the receiver operating characteristic curve of 0.925 (95% confidence interval, 0.898, 0.953) and good calibration (unreliability test, P = 0.412). Decision curve analysis demonstrated that the model was also clinically useful.

CONCLUSIONS

This study demonstrated that stone location, stone size, stone density, SSD, and hydronephrosis grade were significant predictors of stone-free failure after SWL guided by ultrasound in patients with ureteral stones. This may guide clinical practice.

The ratio of CT attenuation values of the ureter above/below ureteral stones is a useful preoperative factor for predicting impacted ureteral stones

Impacted stones typically make it difficult to perform ureteroscopic lithotripsy (URSL), so it is useful to preoperatively predict such impaction. We focused on CT attenuation values of the ureter above and below the stone ('HU above' and 'HU below') and calculated their ratio (HAB ratio; HU above/HU below ratio). The aim was to investigate whether HAB ratio could predict impacted stones preoperatively. Between 2011 and 2019, 171 patients from our hospital that had URSL for ureteral stones with pretreatment non-contrast computed tomography (NCCT) were retrospectively identified. Ureteral wall thickness (UWT), ureteral wall volume (UWV) and HAB ratio ('HU above' divided by 'HU below') were recorded. Impacted stones were defined as fixed stones that did not move by means of ureteroscopic manipulation or water pressure. Of the 171 procedures, 46 (27%) involved patients with impacted stones. Comparing patient characteristics and stone parameters according to impaction status, factors with significant difference included grade of hydronephrosis, UWT, and HAB ratio (all P < 0.01). Multivariate analysis indicated that significant independent predictors of impacted stones were thicker UWT and lower HAB ratio (all P < 0.01). HAB ratio was a significant preoperative predictor of stone impaction in patients undergoing URSL for ureteral stones. HAB ratio may be informative for selecting the treatment and preoperative preparations.

A 3D finite element model to study the cavitation induced stresses on blood-vessel wall during the ultrasound-only phase of photo-mediated ultrasound therapy

Photo-mediated ultrasound therapy (PUT) is a novel technique utilizing synchronized ultrasound and laser to generate enhanced cavitation inside blood vessels. The enhanced cavitation inside blood vessels induces bio-effects, which can result in the removal of micro-vessels and the reduction in local blood perfusion. These bio-effects have the potential to treat neovascularization diseases in the eye, such as age-related macular degeneration and diabetic retinopathy. Currently, PUT is in the preclinical stage, and various PUT studies on in vivo rabbit eye models have shown successful removal of micro-vessels. PUT is completely non-invasive and particle-free as opposed to current clinical treatments such as anti-vascular endothelial growth factor therapy and photodynamic therapy, and it precisely removes micro-vessels without damaging the surrounding tissue, unlike laser photocoagulation therapy. The stresses produced by oscillating bubbles during PUT are responsible for the induced bio-effects in blood vessels. In our previous work, stresses induced during the first phase of PUT due to combined ultrasound and laser irradiation were studied using a 2D model. In this work, stresses induced during the third or last phase of PUT due to ultrasound alone were studied using a 3D finite element method-based numerical model. The results showed that the circumferential and shear stress increased as the bubble moves from the center of the vessel toward the vessel wall with more than a 16 times increase in shear stress from 1.848 to 31.060 kPa as compared to only a 4 times increase in circumferential stress from 211 to 906 kPa for a 2 µm bubble placed inside a 10 µm vessel on the application of 1 MHz ultrasound frequency and 130 kPa amplitude. In addition, the stresses decreased as the bubble was placed in smaller sized vessels with a larger decrease in circumferential stress. The changes in shear stress were found to be more dependent on the bubble-vessel wall distance, and the changes in circumferential stress were more dependent on the bubble oscillation amplitude. Moreover, the bubble shape changed to an ellipsoidal with a higher oscillation amplitude in the vessel's axial direction as it was moved closer to the vessel wall, and the bubble oscillation amplitude decreased drastically as it was placed in vessels of a smaller size.

Predicting ureteral status below the ureteral calculi in patients undergoing ureteroscopic lithotomy

BACKGROUND

During ureteroscopy, severe ureter straightness or contortion may occur before the stone is passed.

PURPOSE

To identify clinical factors associated with distal ureteral status below the ureteral calculi in patients before surgery.

MATERIAL AND METHODS

From October 2016 to March 2017, 101 patients with ureteral calculi who underwent ureteroscopic lithotripsy were reviewed. Patients who lacked clinical data and underwent preoperative indwelling ureteral stent placement were excluded. Univariate and multivariate analyses were performed to determine the clinical factors associated with intraoperative findings.

RESULTS

A total of 101 patients were enrolled in the study (mean age  =  54 years; mean stone size  =  7.9 ± 4.5 mm). Overall, 25 of the 101 patients (24.7%) were diagnosed with poor distal ureteral status defined as intraoperative ureterostenosis or contortion resulting in a ureteroscope being unable to pass during the initial attempt. Univariate analysis showed significant differences in renal parenchyma thickness, ureteral wall thickening on imaging, and stone location (all, P < 0.05) with and without poor distal ureteral status. On multivariable analysis, renal parenchyma thickness (adjusted odds ratio [aOR] 0.288; 95% confidence interval [CI] 0.099-0.838; P = 0.022) and ureteral wall thickening on imaging (aOR 6.114; 95% CI 2.015-18.548; P = 0.001) independently predicted poor distal ureteral status. However, only renal parenchyma thickness was associated with severe ureter straightness or tortuosity that resulted in conversion.

CONCLUSION

In conclusion, renal parenchyma thickness and ureteral wall thickening on imaging were associated with poor distal ureteral status. Therefore, patients with these predictive factors should undergo more intensive preparation before surgery.

Determining whether previous SWL for ureteric stones influences the results of ureteroscopy as the second-line treatment: A clinical study

The purpose of the study was to establish whether shock wave lithotripsy (SWL) is a potential harmful first-line treatment for ureteric stones where ureteroscopy (URS) is necessary as a second-line treatment. Medical records of patients with ureteric stones who underwent either URS as the only therapy applied or SWL followed by URS over two years were retrospectively evaluated. In total, 158 patients were included: 79 patients in Group A (no SWL) and 79 in Group B (prior SWL before URS). There was no difference in major complications, Group A had higher stone-free rates, Group B had higher rates of ureteral edema and similar intraoperative ureteral lesions. In conclusion, the failure of SWL for lumbar or pelvic ureteral lithiasis does not appear to have a negative effect on the rate of intraoperative complications or the success rate of semi-rigid retrograde URS for this category of calculi, with the same safety profile as first-line endourological intervention.

Development and validation of a preoperative nomogram for predicting patients with impacted ureteral stone: a retrospective analysis

Background

To develop and validate a practical nomogram for predicting the probability of patients with impacted ureteral stone.

Methods

Between June 2020 to March 2021, 214 single ureteral stones received ureteroscopy lithotripsy (URSL) were selected in development group. While 82 single ureteral stones received URSL between April 2021 to May 2021 were included in validation group. Independent factors for predicting impacted ureteral stone were screened by univariate and multivariate logistic regression analysis. The relationship between preoperative factors and stone impaction was modeled according to the regression coefficients. Discrimination and calibration were estimated by area under the receiver operating characteristic (AUROC) curve and calibration curve respectively. Clinical usefulness of the nomogram was evaluated by decision curve analysis.

Results

Age, ipsilateral stone treatment history, hydronephrosis and maximum ureteral wall thickness (UWT_max) at the portion of stone were identified as independent predictors for impacted stone. The AUROC curve of development and validation group were 0.915 and 0.882 respectively. Calibration curve of two groups showed strong concordance between the predicted and actual probabilities. Decision curve analysis showed that the predictive nomogram had a superior net benefit than UWT_max for all examined probabilities.

Conclusions

We developed and validated an individualized model to predict impacted ureteral stone prior to surgery. Through this prediction model, urologists can select an optimal treatment method and decrease intraoperative and postoperative complications for patients with impacted ureteral calculus.

Laparoscopic ureterolithotomy and retrograde flexible ureteroscopy-assisted transperitoneal laparoscopic ureteroureterostomy for a huge ureteropelvic junction stone and multiple small renal stones: A CARE-compliant case report

RATIONALE

Concurrent kidney and ureteral stones are always complicated and a clinical challenge. Improvements in endoscopic equipment have led to the widespread adoption of retrograde intrarenal surgery, which has a good stone clearance rate. On the other hand, laparoscopic ureterolithotomy (LUL) has been reported to be non-inferior to retrograde flexible ureteroscopy in stone-free rate and the need for axillary procedures, and to have a significantly lower rate of post-operative sepsis compared to retrograde flexible ureteroscopy. We describe a case managed with LUL followed by laparoscope-assisted retrograde intrarenal surgery (LA-RIRS) in a single operation for a large upper ureteral stone and small renal stones, which is usually challenging and requires axillary procedures.

PATIENT CONCERNS

The patient was a 66-year-old male with underlying hypertension and diabetes mellitus. He reported severe flank pain after receiving endoscopic management of concurrent right ureteropelvic junction stone and multiple renal stones about 1 month previously.

DIAGNOSIS

The residual stones were reassessed using non-contrast computed tomography before surgery. A 2.8-cm residual ureteropelvic junction stone and multiple renal stones with a maximum length of 1 cm were found. A second operation was considered to be necessary due to the deterioration of his renal function and refractory flank pain.

INTERVENTIONS

We performed LUL followed by LA-RIRS. Two surgeries were completed in a single operation. The Jackson-Pratt drain was removed 3 days after the operation.

OUTCOMES

After the surgery, no high-grade complications were recorded according to the Clavien Dindo classification. A follow-up kidney, ureter, and bladder radiograph performed 2 months after the operation revealed no residual stones. Renal echo revealed no obstructive nephropathy 1 month after double-J catheter removal.

CONCLUSION

LUL with LA-RIRS with a stone basket for renal stone extraction is a safe and feasible technique, and no step surgery or axillary procedures were needed in our case. If clinical cases with a huge stone burden over the ureter are indicated for LUL with concurrent small renal stones, LUL with LA-RIRS can be an alternative option.

Can ureteral wall thickness (UWT) be used as a potential parameter for decision-making in uncomplicated distal ureteral stones 5-10 mm in size? A prospective study

OBJECTIVE

To evaluate the correlation between ureteral wall thickness (UWT) and stone passage (SP) and its cut-off value in distal uncomplicated ureteral stones.

PATIENTS AND METHODS

In the prospective study from January 2019 to January 2020 at a tertiary care hospital, we reviewed 212 patients aged above 18 years with single, symptomatic, radiopaque, and distal ureteric stone sized 5-10 mm, who were treated with MET (Silodosin 8 mg once daily) until SP or a maximum of 4 weeks. There were 2 groups: responders and non-responders. Demographic data of the patients and all stone radiological parameters including stone size, laterality, density, UWT, the diameter of the ureter proximal to the stone (PUD), and the degree of hydronephrosis were recorded and compared between the 2 groups.

RESULTS

There were 126 (59.4%) in the responder group and 86 (40.6%) in the non-responder group. On univariate analysis, gender, stone density, stone size, PUD, UWT, and the degree of hydronephrosis were significant factors for stone passage. However, using multivariate analysis, only UWT and the degree of hydronephrosis were significant. ROC analysis showed that 3.75 mm is the cut-off value for UWT, with 86% and 87.3% sensitivity and specificity, respectively.

CONCLUSIONS

UWT and hydronephrosis can be used as potential predictors for SP and can help with decision-making in patients with uncomplicated 5-10 mm lower ureteric stones.

Ex Vivo Imaging of Ultrasound-Stimulated Metabolic Activity in Rat Pancreatic Slices

Ultrasound has previously been reported to produce a reversible stimulatory effect in cultured rat beta cells. Here, we quantified and assessed dynamic metabolic changes in an in situ pancreatic slice model evoked by ultrasound application. After plating, pancreas slices were imaged using a confocal microscope at 488 and 633 nm to image lipodamine dehydrogenase (Lip-DH) autofluorescence and a far red fluorescence, respectively. Ultrasound was applied at intensities of 0.5 and 1 W/cm2 at both 800 kHz and 1 MHz. Additionally, 800 kHz at 1 W/cm2 was applied in a pulsing scheme. No ultrasound (control) and glucose application experiments were performed. A difference in fluorescence signal before and after treatment application was the metric for analysis. Comparison of experimental groups using far red fluorescence revealed significant differences between all experimental groups and control in the islet (p < 0.05) and between all ultrasound experimental groups and control (p < 0.05) in pancreatic exocrine tissue. However, this difference in response between control and glucose did not exist in the exocrine tissue. We also observed using Lip-DH autofluorescence that glucose produces a significantly increased metabolic response in islet tissue compared with exocrine tissue (p < 0.05). Pulsed ultrasound appeared to increase metabolic activity in the pancreatic slice in a more consistent manner compared with continuous ultrasound application. Our results indicate that therapeutic ultrasound may have a stimulatory metabolic effect on the pancreatic islets similar to that of glucose.

Impacted ≥ 10-mm pelvic ureteric stone treatment: laser lithotripsy alone or in combination with pneumatic lithotripsy—a prospective, comparative study

Background

The aim of this study is to evaluate the outcome of ureteroscopic lithotripsy of combined pneumatic and laser versus laser lithotripsy alone for the treatment of impacted pelvic ureteral stones. Ninety patients with impacted stones 10 mm or more were selected and divided into two equal groups. The combined group included patients who treated by pneumatic lithotripsy (PL) and laser lithotripsy (LL), while those in the laser group were treated by LL alone via retrograde semirigid ureteroscopy. Exclusion criteria included urinary tract infection, radiolucent stones, ipsilateral concurrent stone, previous ureteral surgery, urinary tract anomalies, musculoskeletal deformities, renal failure and pregnancy. Any stone retropulsion or any residual stone detected 1 month postoperative was considered failure.

Results

The stone-free rate was 88.8% and 91.1% for laser and combined groups, respectively, which was statistically insignificant (p ≥ 0.05). Operative complications were 11.11% versus 4.4% for laser and combined groups, respectively, which is significant statistically (p ˂ 0.05). No ureteral perforation and no stricture were developed in the combined group, while one perforation and two strictures were developed in the laser group. The DJ stenting and second session lithotripsy requirements were 64.4% versus 51.1% and 15.5% versus 8.8% for laser versus combined group, respectively, and each was statistically significant.

Conclusion

When treating impacted stones, combining PL to LL can decrease the complication rate, DJ stenting and second session lithotripsy requirement, while preserving laser fragmentation capabilities.

Management of ureteric stone in pregnancy: a review

Background

Urolithiasis in pregnancy is a major health concern and is one of the most common causes for non-obstetrical abdominal pain and subsequent hospital admission during pregnancy. The incidence of urinary calculi during pregnancy varies in the range of 1/200 to 1/2000. Acute ureteric colic in pregnancy is associated with significant potential risks to both mother and fetus. Significant anatomic and functional changes occur in pregnancy which not only lead to stone formation but also create diagnostic dilemma. The diagnosis of ureteric calculi can be incorrect in about 28% of pregnant patients.

Main body

Management of ureteric stone during pregnancy is remaining to be a challenge for the treating urologist. Because of the inability to use good imaging options for the diagnosis confirmation and more invasive approach for the treatment, management continues to be difficult. The main threats are preterm labor with delivery and premature rupture of membranes. Other pregnancy complications are obstructive uropathy, gestational diabetes mellitus, recurrent abortions and pre-eclampsia. Management of diagnosed ureteric stone is unique in the pregnant population and requires multi-disciplinary care. It should be individualized for each patient and moves preferably from conservative to invasive approaches sequentially. With continued advancements in endourological techniques, few definitive treatment options are also available for such patients.

Conclusion

There are several lacunae related with the diagnostic imaging, medical expulsive therapy, reliability of ureteral stent/percutaneous nephrostomy insertions and safety of ureteroscopy during pregnancy. Herein, we review the management of ureteric stone during pregnancy, the various diagnostic modalities and treatment options with their advantages and disadvantages. We also proposed our management algorithm to deal with such clinical scenario in this particular population.

Role of pretreatment Doppler ultrasound in the prediction of factors affecting stone-clearance post-shockwave lithotripsy for ureteral stones: a prospective study

PURPOSE

To identify the role of Doppler US (DUS) in the prediction of factors affecting stone-clearance post-SWL for ureteral stones in addition to its role in prediction of pretreatment stone impaction.

METHODS

We prospectively included patients with ureteric stone for SWL between October 2018 and September 2019. Patient's demographics were collected. Using DUS, resistive index (RI), Δ RI, and ureteric jets were evaluated in both kidneys. Also, stone site, volume, density, skin to stone distance, degree of hydronephrosis, ureteral wall thickness (UWT) were evaluated by NCCT. Univariate and multivariate logistic regression analyses were performed to identify factors that contribute to treatment success. Correlation between ipsilateral RI with other radiological findings predicting stone impaction was done.

RESULTS

A total of 93 patients were finally included (61 males and 32 females). The mean age was 31.4 ± 7.7 years. The success rate (absence of significant residuals post 1 month by NCCT) was 51.6%. In multivariate analysis, the presence of ureteric jet, ipsilateral lower RI, and ipsilateral lower UWT were independent factors for treatment success (P = 0.0001, 0.002, and 0.03, respectively). Also, ipsilateral absence of ureteric jet, increased hydronephrosis, and increased UWT were correlated with higher ipsilateral RI in prediction of stone impaction. Ipsilateral higher RI was found to achieve higher accuracy in stone impaction prediction (PPV of 94.8%).

CONCLUSION

Pretreatment DUS is a useful, non-invasive with a less irradiative tool for prediction of stone impaction and stone-free rate post-SWL for ureteric stones.

Extracorporeal shock wave lithotripsy under intravenous sedation for treatment of urolithiasis

BACKGROUND

In contrast to treatment with oral or intramuscular analgesics, extracorporeal shock wave lithotripsy (E.S.W.L.) can be performed with patients under sedation too. Besides the advantage of increased shock energy, patients tend to have more constant breathing excursions and are more idle during treatment, potentially increasing the stone-free ratio (S.F.R.) after treatment.

METHODS

This study presents the results of 310 patients who underwent 400 E.S.W.L. procedures under sedation, with a stationary lithotripter.

RESULTS

After one procedure, the S.F.R. was 54.8% (170/310). A second treatment was successful in 42.1% (32/76), a third treatment in 21.4% (3/14). Therefore, 66.1% (205/310) of patients eventually became stone-free. Kidney stones were successfully treated in 65.4% (161/246), ureteral stones in 68.8% (44/64) of cases. Patients with stones ≤15 mm were successfully treated in 67.4% (194/288), patients with stones >15 mm in 50% (11/22) of cases. Considering each procedure individually, 45.3% (181/400) of procedures were successful after 3 weeks. Extending follow-up to 3 months is important, since 26.7% of stones (24/90) eventually still disappeared, increasing S.F.R. to 51.3% after one procedure. Complications occurred after 5.5% E.S.W.L.-procedures.

CONCLUSIONS

E.S.W.L. is a well-tolerated, non-invasive procedure that produces reasonable stone clearance of both upper and lower urinary tract calculi. Performing the procedure whilst patients are intravenously sedated results in an acceptable S.F.R. Strong selection based on unfavourable factors could increase the chance on successful treatment and spare patients a pointless procedure. However, considering E.S.W.L.'s elegant nature, sometimes a more tolerant approach seems justifiable.

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.

Stones in pregnancy and pediatrics

Urinary stone disease is a highly prevalent condition affecting approximately 10% of the population, and has increased in incidence significantly over the past 20 years. Along with this, the rate of stone disease among women and children is also on the rise. The management of stone disease in specific populations, such as in children and during pregnancy can present unique challenges to the urologist. In both populations, a multi-disciplinary approach is strongly recommended given the complexities of the patients. Prompt and accurate diagnosis requires a high degree of suspicion and judicious use of diagnostic imaging given the higher risks of radiation exposure. In general, management proceeds from conservative to more invasive approaches and must be individualized to the patient with careful consideration of the potential adverse effects. However, innovations in endourologic equipment and techniques have allowed for the wider application of surgical stone treatment in these patients, and significant advancement in the field. This review covers the history and current advances in the diagnosis and management of stone disease in pregnant and pediatric populations. It is paramount for the urologist to understand the complexities of properly managing stones in these patients in order to maximize treatment efficacy, while minimizing complications and morbidity.

Review on diagnosis and management of urolithiasis in pregnancy: an ESUT practical guide for urologists

PURPOSE

Management of urolithiasis in pregnancy can be challenging for most urologists with diagnostic and treatment dilemma to ensure the best outcome for both mother and fetus. We wanted to review the literature for urolithiasis in pregnancy with a practical management guide for urologists.

METHODS

A non-systematic review of literature was carried out for all English language literature using Medline. To ensure a more comprehensive search, the review of diagnosis and management of pregnant patients with urolithiasis was carried out separately, by two authors independently. Due to diagnostic complexity, investigations (US, CT, MRI) carried out were assessed separately.

RESULTS

Our search included diagnostic studies such as US, CT and MRI (73, 20 and 27 articles, respectively) and management studies (55 articles in total). Details on etiology, radiation risk, safety of various diagnostic modalities, medications and treatment options are covered through an evidence-based approach. We provide a practical guide for urologists in what is clearly a stressful situation for patient and physician alike.

CONCLUSIONS

Urolithiasis in pregnancy needs a careful multidisciplinary management to achieve good outcomes for both mother and baby. Our review shows that a balanced approach for diagnosis and treatment seems to achieve the best outcomes in pregnancy.

Shockwave lithotripsy: techniques for improving outcomes

OBJECTIVES

Shock wave lithotripsy (SWL) remains the only effective truly non-invasive treatment for nephrolithiasis. While single-treatment success rates may not equal those of ureteroscopy and percutaneous nephrolithotomy, it has an important role to play in the management of stones. In this paper, we outline the latest evidence-based recommendations for maximizing SWL outcomes, while minimizing complications.

MATERIALS AND METHODS

A comprehensive review of the current literature was performed regarding maximizing SWL outcomes.

RESULTS

Several different considerations need to be made regarding patient selection with respect to body habitus, body mass index, anatomical location and underlying urologic abnormalities. Stone composition and stone density (Hounsfield Units) are important prognostic variables. Patient positioning is critical to allow for adequate stone localization with either fluoroscopy or ultrasound. Coupling should be optimized with a low viscosity gel applied to the therapy head first and patient movement should be limited. SWL energy should be increased slowly and shockwave rates of 60 or 90 Hz should be used. Medical expulsive therapy with alpha-blockers after SWL treatment has shown benefit, particularly with stones greater than 10 mm.

CONCLUSION

While single-treatment success rates may not equal those of ureteroscopy or percutaneous nephrolithotomy, with proper patient selection, optimization of SWL technique, and use of adjunctive treatment after SWL, success rates can be maximized while further reducing the already low rate of serious complications. SWL remains an excellent treatment option for calculi even in 2017.

Ureteral Wall Thickness as a Preoperative Indicator of Impacted Stones in Patients With Ureteral Stones Undergoing Ureteroscopic Lithotripsy

OBJECTIVE

To evaluate the clinical significance of ureteral wall thickness (UWT) to predict the presence of impacted stones in patients with ureteral stones undergoing ureteroscopic lithotripsy (URSL).

MATERIALS AND METHODS

We retrospectively analyzed 130 procedures in patients with ureteral stones who underwent URSL between January 2014 and September 2016. Maximum UWT at the stone site was measured from computed tomography images. Clinical predictors of impacted stones were assessed using univariate and multivariate logistic regression analyses. Receiver operating characteristic curve analysis was applied to determine the UWT cutoff value and to evaluate its accuracy in predicting impacted stones. Moreover, we evaluated the association between UWT and endoscopic findings, as well as surgical outcomes.

RESULTS

Of the 130 procedures, 50 (38.5%) involved patients with impacted stones. The univariate analysis showed significant differences in age, hydronephrosis, stone location, stone burden, and UWT in patients with and without impacted stones, and the multivariate analysis showed that age, stones in the middle ureter, and UWT (odds ratio 5.43, P < .001) were independent predictors of impacted stones. The receiver operating characteristic analysis showed that 3.49 mm was the optimal cutoff value for UWT, with a predictive accuracy of 0.87. High UWTs were associated with the presence of ureteral edema, polyps, white lesions, stone fixation, longer operation time, and lower endoscopic stone-free rate, compared with low UWTs (P < .05 each).

CONCLUSION

High UWT is associated not only with a higher risk of impacted stones but also with poor endoscopic findings and adverse surgical outcomes in patients with ureteral stones undergoing URSL.

Recent advances in lithotripsy technology and treatment strategies: A systematic review update

INTRODUCTION

Shock wave lithotripsy (SWL) is a well - established treatment option for urolithiasis. The technology of SWL has undergone significant changes in an attempt to better optimize the results while reducing failure rates. There are some important limitations that restrict the use of SWL. In this review, we aim to place these advantages and limitations in perspective, assess the current role of SWL, and discuss recent advances in lithotripsy technology and treatment strategies.

METHODS

A comprehensive review was conducted to identify studies reporting outcomes on ESWL. We searched for literature (PubMed, Embase, Medline) that focused on the physics of shock waves, theories of stone disintegration, and studies on optimising shock wave application. Relevant articles in English published since 1980 were selected for inclusion.

RESULTS

Efficacy has been shown to vary between lithotripters. To maximize stone fragmentation and reduce failure rates, many factors can be optimized. Factors to consider in proper patient selection include skin - to - stone distance and stone size. Careful attention to the rate of shock wave administration, proper coupling of the treatment head to the patient have important influences on the success of lithotripsy.

CONCLUSION

Proper selection of patients who are expected to respond well to SWL, as well as attention to the technical aspects of the procedure are the keys to SWL success. Studies aiming to determine the mechanisms of shock wave action in stone breakage have begun to suggest new treatment strategies to improve success rates and safety.

Molecular mechanisms of the angiogenic effects of low-energy shock wave therapy: roles of mechanotransduction

We have previously demonstrated that low-energy extracorporeal cardiac shock wave (SW) therapy improves myocardial ischemia through enhanced myocardial angiogenesis in a porcine model of chronic myocardial ischemia and in patients with refractory angina pectoris. However, the detailed molecular mechanisms for the SW-induced angiogenesis remain unclear. In this study, we thus examined the effects of SW irradiation on intracellular signaling pathways in vitro. Cultured human umbilical vein endothelial cells (HUVECs) were treated with 800 shots of low-energy SW (1 Hz at an energy level of 0.03 mJ/mm(2)). The SW therapy significantly upregulated mRNA expression and protein levels of vascular endothelial growth factor (VEGF) and endothelial nitric oxide synthase (eNOS). The SW therapy also enhanced phosphorylation of extracellular signal-regulated kinase 1/2 (Erk1/2) and Akt. Furthermore, the SW therapy enhanced phosphorylation of caveolin-1 and the expression of HUTS-4 that represents β1-integrin activity. These results suggest that caveolin-1 and β1-integrin are involved in the SW-induced activation of angiogenic signaling pathways. To further examine the signaling pathways involved in the SW-induced angiogenesis, HUVECs were transfected with siRNA of either β1-integrin or caveolin-1. Knockdown of either caveolin-1 or β1-integrin suppressed the SW-induced phosphorylation of Erk1/2 and Akt and upregulation of VEGF and eNOS. Knockdown of either caveolin-1 or β1-integrin also suppressed SW-induced enhancement of HUVEC migration in scratch assay. These results suggest that activation of mechanosensors on cell membranes, such as caveolin-1 and β1-integrin, and subsequent phosphorylation of Erk and Akt may play pivotal roles in the SW-induced angiogenesis.

A new optical coupling control technique and application in SWL

The objective of this study was to compare the results of shock wave lithotripsy (SWL) between patients treated with optical coupling control (OCC) and those treated with "blind" coupling during SWL to treat renal stones. Enrolled in the study were patients with urinary stones who underwent SWL between January 2014 and February 2015. The lithotripter used in the study was an electromagnetic Dornier Compact Delta II UIMS. The closed envelope method was used to randomize the enroled patients to OCC (Group A) or "Blind" coupling group (Group B). The stone-free rates (SFRs) were determined using KUB film with or without ultrasonography after 3 months. Treatment failure was defined as radiologically confirmed persistence of the stone with no fragmentation after second SWL sessions. Complications during the intraoperative or post-operative periods were recorded. A total of 336 patients satisfied the inclusion criteria for the study, of which 169 patients were treated in the Group A and 167 in the Group B. There was no significant difference in patient and stone characteristics between the two groups (Table 1). The locations of treated stones are shown in Table 2. The treatment results were stratified by stone location in Table 3, significant differences existed in all treatment results between the two groups (P < 0.05). The overall stone-free rates after 3 months were 78.2 % for kidney stones and 81.7 % for ureteral stones in patients from Group A. The corresponding SFRs for patients in Group B were 62.8 and 67.9 % for stones in the kidneys and ureters, respectively. There were statistical differences in these results between the two groups (P < 0.05). The lithotripter with OCC had excellent shock wave transmission properties with the least possible loss of energy; it can lead to the optimization of SWL treatment outcome and reduce the incidence of SW-induced adverse effects. We are confident that the OCC used in this study should be a standard feature in future lithotripters. Table 1 Patients' and stones' characteristics Group A Group B P value Number of patients 169 167 Patients' gender (M/F) 97/72 109/58 0.138 Stone location (left/right) 86/83 89/78 0.659 Patients' age (years) 36.3 ± 7.1 34.2 ± 6.8 0.521 Size of stones  Kidney (cm) 1.4 ± 0.6 1.3 ± 0.7 0.452  Ureter (cm) 1.1 ± 0.5 1.1 ± 0.4 0.354  Average size (cm) 1.2 ± 0.8 1.2 ± 0.7 0.372 Table 2 The distribution of location of stones treated Group A % Group B % Upper calyx 21 12.4 25 15.0 Middle calyx 28 16.6 23 13.8 Lower calyx 7 4.1 5 3.0 Renal pelvis 31 18.3 33 19.8 Upper ureter 28 16.6 31 18.6 Middle ureter 6 3.6 4 2.4 Lower ureter 48 28.4 46 27.5 Overall 169 100.0 167 100.0 Table 3 The treatment results were stratified by stone location Group A Group B %Stone-free %Re-treatment %Ancillary procedure %Stone-free %Re-treatment %Ancillary procedure Kidney  Upper calyx 76.2 33.3 14.3 60.0 48.0 12.0  Middle calyx 75.0 35.7 7.1 56.5 56.5 13.0  Lower calyx 71.4 42.9 28.6 60.0 60.0 40.0  Renal pelvis 83.9 29.0 9.7 69.7 45.5 12.1  Overall 78.2 33.3 11.5 62.8 50. 0 14.0 Ureter  Upper ureter 82.1 28.6 10.7 74.2 32.3 16.1  Middle ureter 66.7 66.7 33.3 50. 75.0 50.0  Lower ureter 83.3 25.0 10.4 65.0 41.3 13.0  Overall 81.7 29.3 12.2 67.9 39.5 16.0.

Ultrasound Transducers

Diagnostic medical ultrasound transducers have evolved through the years and have contributed significantly to improved patient care. This article discusses the history and types of transducers and the elements that have changed over time. There has been a sharp transition from natural to human-made elements and from one to many in a single transducer. Ergonomics also now plays a role in transducer design and will continue to do so; the grip, weight, and size of transducers are in the forefront of design considerations. The evolution of transducers has changed not only how well we visualize anatomy and what anatomy we see but also how the patient’s care is managed. Different, new, and emerging technologies certainly will continue to be identified within the sonography community.

Ureteroscopy in proximal ureteral stones after shock wave lithotripsy failure: Is it safe and efficient or dangerous?

INTRODUCTION

We assessed the effectiveness of ureteroscopy (URS) in proximal ureteral stones performed after shock wave lithotripsy (SWL) failure, and determined outcomes in terms of success rate, complications, and operation time.

METHODS

We analyzed data of patients with previous unsuccessful SWL (Group I) and the ones that did not have SWL or URS before (Group II) for proximal ureteral stones between December 2007 and August 2014. Group I included 346 patients who underwent complementary URS and Group II 209 patients who underwent primary URS. Success rates, operation time and complications were compared between groups.

RESULTS

Success rates of complementary and primary URS were 78.9% and 80.9%, respectively. The difference in success rates was not statistically significant between groups (p = 0.57). The complication rates of complementary URS was 12.1%, and 9.5% in primary URS (p = 0.49). No statistically significant differences were noted in terms of gender, age, stone size and side, or lithotripter type between groups. The mean operation time and need for balloon dilatation were higher in complementary URS group compared to the primary URS group, and the difference was statistically significant (p < 0.05).

CONCLUSIONS

Complementary URS may be used safely after SWL failure in proximal ureteral stones. Its success rate and morbidities are similar to primary URS, except for longer operation time and an increased need for balloon dilatation.

Efficacy of surgical techniques and factors affecting residual stone rate in the treatment of kidney stones

OBJECTIVE

In this study, we aimed to evaluate, the efficacy of surgical methods and the factors affecting the residual stone rate by scrutinizing retrospectively the patients who had undergone renal stone surgery.

MATERIAL AND METHODS

Records of 109 cases of kidney stones who had been surgically treated between January 2010, and July 2013 were reviewed. Patients were divided into three groups in terms of surgical treatment; open stone surgery, percutaneous nephrolithotomy (PNL) and retrograde intrarenal surgery (RIRS). Patients' history, physical examination, biochemical and radiological images and operative and postoperative data were recorded.

RESULTS

The patients had undergone PNL (n=74; 67.9%), RIRS (n=22;20.2%), and open renal surgery (n=13; 11.9%). The mean and median ages of the patients were 46±9, 41 (21-75) and, 42 (23-67) years, respectively. The mean stone burden was 2.6±0.7 cm(2) in the PNL, 1.4±0.1 cm(2) in the RIRS, and 3.1±0.9 cm(2) in the open surgery groups. The mean operative times were 126±24 min in the PNL group, 72±12 min in the RIRS group and 82±22 min in the open surgery group. The duration of hospitalisation was 3.1±0.2 days, 1.2±0.3 days and 3.4±1.1 days respectively. While the RIRS group did not need blood transfusion, in the PNL group blood transfusions were given in the PNL (n=18), and open surgery (n=2) groups. Residual stones were detected in the PNL (n=22), open surgery (n=2), and RIRS (n=5) groups.

CONCLUSION

PNL and RIRS have been seen as safe and effective methods in our self application too. However, it should not be forgotten that as a basical method, open surgery may be needed in cases of necessity.

Ureteral wall thickness at the impacted ureteral stone site: a critical predictor for success rates after SWL

The aim of the study was to determine the possible predictive value of certain patient- and stone-related factors on the stone-free rates and auxiliary procedures after extracorporeal shock wave lithotripsy in patients with impacted proximal ureteral calculi. A total of 111 patients (86 male, 25 females M/F: 3.44/1) with impacted proximal ureteral stones treated with shock wave lithotripsy were evaluated. Cases were retrieved from a departmental shock wave lithotripsy database. Variables analyzed included BMI of the case, diameter of proximal ureter and renal pelvis, stone size and Hounsfield unit, ureteral wall thickness at the impacted stone site. Stone-free status on follow-up imaging at 3 months was considered a successful outcome. All patients had a single impacted proximal ureteral stone. While the mean age of the cases was 46 ± 13 years (range 26-79 years), mean stone size was 8.95 mm (5.3-15.1 mm). Following shock wave lithotripsy although 87 patients (78.4%) were completely stone-free at 3-month follow-up visit, 24 (21.6%) cases had residual fragments requiring further repeat procedures. Prediction of the final outcome of SWL in patients with impacted proximal ureteral stones is a challenging issue and our data did clearly indicate a highly significant relationship between ureteral wall thickness and the success rates of shock wave lithotripsy particularly in cases requiring additional procedures. Of all the evaluated stone- and patient-related factors, only ureteral wall thickness at the impacted stone site independently predicted shock wave lithotripsy success.

Flexible ureteroscopic renal stone extraction during laparoscopic ureterolithotomy in patients with large upper ureteral stone and small renal stones

INTRODUCTION

We describe laparoscopic ureterolithotomy with renal stone extraction using a stone basket under flexible ureteroscopy. We describe its efficacy through a laparoscopic port and a ureterotomy site in patients with large upper ureteral stone and small renal stones.

METHODS

Between January 2009 and February 2012, we performed laparoscopic ureterolithotomy with renal stone extraction using a stone basket under flexible ureteroscopy in 11 patients who had upper ureteral and renal stones. The retroperitoneal approaches were used in all patients using 3-4 trocars.

RESULTS

All procedures were performed successfully without significant complications. Mean operative time was 78.5 minutes (range: 52-114 minutes). The mean size of ureteral stone was 19.91 mm (range: 15-25 mm). In addition, 25 renal stones (mean size 7.48 mm, range: 2-12 mm) were removed from 11 patients. The mean length of hospital stay was 3.5 days (range: 2-6 days).

CONCLUSIONS

Laparoscopic ureterolithotomy with renal stone extraction using a stone basket under flexible ureteroscopy can be considered one of treatment modalities for patients with large upper ureteral stones accompanied by renal stones who are indicated in laparoscopic ureterolithotomy.

Lithotripter outcomes in a community practice setting: comparison of an electromagnetic and an electrohydraulic lithotripter

PURPOSE

We assessed patient outcomes using 2 widely different contemporary lithotripters.

MATERIALS AND METHODS

We performed a consecutive case series study of 355 patients in a large private practice group using a Modulith® SLX electromagnetic lithotripter in 200 patients and a LithoGold LG-380 electrohydraulic lithotripter (TRT, Woodstock, Georgia) in 155. Patients were followed at approximately 2 weeks. All preoperative and postoperative films were reviewed blindly by a dedicated genitourinary radiologist. The stone-free rate was defined as no residual fragments remaining after a single session of shock wave lithotripsy without an ancillary procedure.

RESULTS

Patients with multiple stones were excluded from analysis, leaving 76 and 142 treated with electrohydraulic and electromagnetic lithotripsy, respectively. The stone-free rate was similar for the electrohydraulic and electromagnetic lithotripters (29 of 76 patients or 38.2% and 69 of 142 or 48.6%, p = 0.15) with no difference in the stone-free outcome for renal stones (20 of 45 or 44.4% and 33 of 66 or 50%, p = 0.70) or ureteral stones (9 of 31 or 29% and 36 of 76 or 47.4%, respectively, p = 0.08). The percent of stones that did not break was similar for the electrohydraulic and electromagnetic devices (10 of 76 patients or 13.2% and 23 of 142 or 16.2%) and ureteroscopy was the most common ancillary procedure (18 of 22 or 81.8% and 30 of 40 or 75%, respectively). The overall mean number of procedures performed in patients in the 2 groups was similar (1.7 and 1.5, respectively).

CONCLUSIONS

We present lithotripsy outcomes in the setting of a suburban urology practice. Stone-free rates were modest using shock wave lithotripsy alone but access to ureteroscopy provided satisfactory outcomes overall. Although the acoustic characteristics of the electrohydraulic and electromagnetic lithotripters differ substantially, outcomes with these 2 machines were similar.

Characterization of the shock pulse-induced cavitation bubble activities recorded by an optical fiber hydrophone

A shock pressure pulse used in an extracorporeal shock wave treatment has a large negative pressure (<-5 MPa) which can produce cavitation. Cavitation cannot be measured easily, but may have known therapeutic effects. This study considers the signal recorded for several hundred microseconds using an optical hydrophone submerged in water at the focus of shock pressure field. The signal is characterized by shock pulse followed by a long tail after several microseconds; this signal is regarded as a cavitation-related signal (CRS). An experimental investigation of the CRS was conducted in the shock pressure field produced in water using an optical hydrophone (FOPH2000, RP Acoustics, Germany). The CRS was found to contain characteristic information about the shock pulse-induced cavitation. The first and second collapse times (t1 and t2) were identified in the CRS. The collapse time delay (tc = t2 - t1) increased with the driving shock pressures. The signal amplitude integrated for time from t1 to t2 was highly correlated with tc (adjusted R(2) = 0.990). This finding suggests that a single optical hydrophone can be used to measure shock pulse and to characterize shock pulse-induced cavitation.

The success of extracorporeal shock-wave lithotripsy based on the stone-attenuation value from non-contrast computed tomography

Objective

To determine the utility of the urinary stone-attenuation value (SAV, in Hounsfield units, HU) from non-contrast computed tomography (NCCT) for predicting the success of extracorporeal shock-wave lithotripsy (ESWL).

Patients and methods

The study included 305 patients with renal calculi of ⩽30 mm and upper ureteric calculi of ⩽20 mm. The SAV was measured using NCCT. Numerical variables were compared using a one-way analysis of variance with posthoc multiple two-group comparisons. Univariate and multivariate regression analysis models were used to test the preferential effect of the independent variable(s) on the success of ESWL.

Results

Patients were grouped according to the SAV as group 1 (⩽500 HU, 81 patients), group 2 (501–1000 HU, 141 patients) and group 3 (>1000 HU, 83 patients). ESWL was successful in 253 patients (83%). The rate of stone clearance was 100% in group 1, 95.7% (135/141) in group 2 and 44.6% (37/83) in group 3 (P = 0.001).

Conclusions

The SAV value is an independent predictor of the success of ESWL and a useful tool for planning stone treatment. Patients with a SAV ⩾956 HU are not ideal candidates for ESWL. The inclusion criteria for ESWL of stones with a SAV <500 HU can be expanded with regard to stone size, site, age, renal function and coagulation profile. In patients with a SAV of 500–1000 HU, factors like a body mass index of >30 kg/m² and a lower calyceal location make them less ideal for ESWL.

Treatment efficacy and outcomes using a third generation shockwave lithotripter

OBJECTIVES

To evaluate the clinical efficiency of a third generation electromagnetic shock wave lithotripter, the Lithoskop(®) (Siemens, Erlangen, Germany), regarding outcomes, stone disintegration, retreatment and complication rates. To compare the results of the Lithoskop with other currently available systems and the reference standard lithotripter, the HM-3 (Dornier MedTech Europe GmbH, Wessling, Germany).

PATIENTS AND METHODS

We analysed the data from 183 patients, including 13 children, undergoing extracorporeal shock wave lithotripsy (ESWL) for renal and ureteric calculi collected from a prospectively populated database. Outcomes were assessed by plain abdominal film of kidney, ureter and bladder and renal ultrasonography for radiopaque and computerized tomography for radiolucent stones 1 day after treatment and after 3 months. We analysed stone size and location before and after treatment, stone disintegration rate, retreatment rate, stone-free and residual fragment rates after 3 months, along with auxiliary procedures and complications.

RESULTS

The mean (range) patient age was 48.6 (1.3-81.4) years, including 13 children with a mean (range) age of 8.4 (1.3-16.7) years, and 77% of the patients were male. In all, 46% of the calculi were localized in the kidney and 54% in the ureter. Renal stones were localized in the upper, middle and lower calyx and in the renal pelvis in 9, 29, 30 and 32% of patients, respectively. Ureteric stones were localized in the upper, mid- and distal ureter in 29, 19 and 52% of patients, respectively. The median (range) stone size before ESWL was 10 (4-25) mm in the kidney and 8 (4-28) mm in the ureteric calculi. The overall stone-free rate after 3 months was 91% (88% for renal and 93% for ureteric calculi); the mean number of sessions to achieve these rates was 1.3. Stone-free rates and the required number of sessions were determined only by stone size. In 7.1% of the patients (n = 13) post-interventional auxiliary procedures were necessary. We observed one perirenal haematoma as a major complication (0.5%), but this did not require any further therapy.

CONCLUSIONS

Clinical stone-free rates with the Lithoskop are high and similar to those of other available systems, including the reference standard HM-3 lithotripter. Retreatment and complication rates are low, supporting the use of ESWL as first-line therapy for urinary calculi <10 mm, independent of stone location.

Does previous failed ESWL have a negative impact of on the outcome of ureterorenoscopy? A matched pair analysis

This study aims to evaluate the outcome of ureteroscopy/ureterorenoscopy (URS) as a salvage procedure for stones resistant to extracorporeal shock wave lithotripsy (ESWL). Between January 2009 and January 2012, 313 patients with upper tract lithiasis were treated by URS. Among them, 87 (27.8 %) had undergone URS after prior ESWL failed to achieve stone clearance (Salvage group). These patients were matched with a group of patients who underwent URS as first-line modality (Primary group). Stone-free rates and adjuvant procedures represented the primary points for comparison. Secondary points for comparison included complications, procedure duration, total laser energy used and length of hospitalization. Matching was possible in all cases. Stone clearance rates were 73.6 and 82.8 % for the Salvage and Primary group, respectively. The difference in stone clearance rates between the two groups was not statistically significant (p = 0.186). A total of 11 patients (12.6 %) in the Primary group and 18 patients (20.7 %) in the Salvage group underwent an adjuvant procedure (p = 0.154). No statistically significant differences were noted in terms of complications, procedure duration and length of hospitalization. In the Primary group, the laser energy used for stone fragmentation was higher (p = 0.043). The rate of ureteric stenting at the end of the procedure was higher for the Salvage group (p = 0.030). Previous failed ESWL is not a predictor for unfavorable outcome of URS. Salvage URS is associated, however, with an increased need for ureteric stenting at the end of the procedure.

Extracorporeal shock wave lithotripsy for management of residual stones after ureterolithotripsy versus mini-percutaneous nephrolithotomy: a retrospective study

Purpose

To compare the efficacy of extracorporeal shock wave lithotripsy in managing residual stones after ureterolithotripsy and mini-percutaneous nephrolithotomy.

Materials and Methods

A retrospective study was carried out of 71 patients with proximal urinary tract stones (greater than 10 mm) who underwent ureterolithotripsy or mini-percutaneous nephrolithotomy at a single institution from 2009 to 2011. The 71 patients were divided into two groups: group I (n = 37) comprised patients who underwent ureterolithotripsy, and group II (n = 34) comprised patients who underwent mini-percutaneous nephrolithotomy. Clinical characteristics, stone-free rates, stone demographics, and complications were evaluated.

Results

The overall stone-free rate was 90.1%. The stone-free rates in groups I and II were 97.3% and 82.4%, respectively. There was a statistically significant difference in the stone-free rates between groups I and II (P = 0.035). Neither serious intraoperative nor postoperative complications were observed. No significant difference in complications was observed between the two groups (P = 0.472).

Conclusions

The results of our study suggest that extracorporeal shock wave lithotripsy is an effective and safe auxiliary procedure for managing residual stones after primary endoscopic surgery. This procedure is associated with a satisfactory stone-free rate and a low complication rate, particularly for residual stones after ureteroscopic procedures.

Kidney stones and pregnancy

Kidney stones are common and do not spare the pregnant population. Although a simple stone event is usually straightforward in the general population, it is complex during pregnancy. Acute nephrolithiasis is associated with a unique set of complications during pregnancy and, because of imaging limitations, diagnosis is challenging. Multidisciplinary care is the key in proper management decisions. The pathophysiology of kidney stone formation in the pregnant state is also unique. Herein, we discuss the complexity of kidney stones and pregnancy.

Critical urologic skills and procedures in the emergency department

The evaluation and management of genitourinary emergencies is a fundamental component of the training and practice of emergency physicians. Urologic procedures are common in the emergency room. Emergency physicians play a vital role in the initial evaluation and treatment because delays in management can lead to permanent damage. This article discusses the most common urologic procedures in which emergency physicians must be proficient for rapid intervention to preserve function and avoid complications. An overview of each procedure is discussed as well as indications, contraindications, equipment, technique, and potential complications.

Indication to open anatrophic nephrolithotomy in the twenty-first century: a case report

Introduction. Advances in endourology have greatly reduced indications to open surgery in the treatment of staghorn kidney stones. Nevertheless in our experience, open surgery still represents the treatment of choice in rare cases. Case Report. A 71-year-old morbidly obese female patient complaining about occasional left flank pain, and recurrent cystitis for many years, presented bilateral staghorn kidney stones. Comorbidities were obesity (BMI 36.2), hypertension, type II diabetes, and chronic obstructive pulmunary disease (COPD) hyperlipidemia. Due to these comorbidities, endoscopic and laparoscopic approaches were not indicated. We offered the patient staged open anatrophic nephrolithotomy. Results. Operative time was 180 minutes. Blood loss was 500 cc. requiring one unit of packed red blood cells. Hospital stay was 7 days. The renal function was unaffected based on preoperative and postoperative serum creatinine levels. Stone-free status of the left kidney was confirmed after surgery with CT scan. Conclusions. Open surgery can represent a valid alterative in the treatment of staghorn kidney stones of very selected cases. A discussion of the current indications in the twenty-first century is presented.

Stone comminution correlates with the average peak pressure incident on a stone during shock wave lithotripsy

To investigate the roles of lithotripter shock wave (LSW) parameters and cavitation in stone comminution, a series of in vitro fragmentation experiments have been conducted in water and 1,3-butanediol (a cavitation-suppressive fluid) at a variety of acoustic field positions of an electromagnetic shock wave lithotripter. Using field mapping data and integrated parameters averaged over a circular stone holder area (R(h)=7 mm), close logarithmic correlations between the average peak pressure (P(+(avg))) incident on the stone (D=10 mm BegoStone) and comminution efficiency after 500 and 1000 shocks have been identified. Moreover, the correlations have demonstrated distinctive thresholds in P(+(avg)) (5.3 MPa and 7.6 MPa for soft and hard stones, respectively), that are required to initiate stone fragmentation independent of surrounding fluid medium and LSW dose. These observations, should they be confirmed using other shock wave lithotripters, may provide an important field parameter (i.e., P(+(avg))) to guide appropriate application of SWL in clinics, and facilitate device comparison and design improvements in future lithotripters.

The lithotripsy table height: a novel predictor of outcome in shockwave lithotripsy

BACKGROUND

Outcome of Extracorporeal Shockwave Lithotripsy (SWL) is determined by physical factors that affect stone fragmentation and clearance.

PURPOSE

To evaluate the predictive value of the Lithotripsy Table Height (LTH) in SWL outcome. Lithotripsy Table Height (LTH) is a variable that represents skin to therapy head distance, and it is proportional to the energy that reaches the stone.

MATERIALS AND METHODS

A prospective study enrolled patients undergoing SWL for radiopaque urinary stones. All procedures were performed using a Modulith SLX (Karl Storz, Germany) Lithotripter. Patient weight, height and age; stone location and size; number of shock waves delivered, and LTH were recorded. One month post-procedure a KUB was obtained. Logistic regression analysis was used to evaluate the effects of these variables on stone-free outcome. A ROC curve was plotted.

RESULTS

Fifty-six patients were enrolled. After one month follow-up, overall success rate (Stone Free) was 83.9% (n = 47). LTH was the only independent predictor of outcome in both univariate and multivariate analysis (p = 0.029). Stone size (p = 0.45) and BMI (p = 0.32) were not significant. In the ROC curve, LTH showed an Area under the Curve = 0.791. Patients with LTH < 218 (n = 8) had relative risk of residual stones = 7.5, odds Ratio: 6.6 (Stone free rate 37.5% vs. 91.5%).

CONCLUSION

LTH appears to be an independent predictor of SWL outcome. High success rates can be expected if LTH > 218. Patients with lower LTH had a less effective therapy, therefore, worse stone fragmentation and clearance. These findings may help improve patient selection for SWL therapy.

Analgesia for pain control during extracorporeal shock wave lithotripsy: Current status

Purpose of Review

A cooperative patient is essential in maintaining stone targeting for optimal fragmentation during extracorporeal shock wave lithotripsy (ESWL). Therefore, it is important to choose an appropriate analgesic with minimal adverse effects. The guidelines for pain management during ESWL have not been established.

Current Status

Various analgesic agents including opioids (morphine, pethidine, and fentanyl), nonsteroidal anti-inflammatory drugs (NSAIDS - diclofenac, propofol, ketorolac, and piroxicam), local anesthetic agents and a number of combinations have been used during ESWL by various techniques (general anesthesia, regional anesthesia, subcutaneous and intravenous injections, patient-controlled analgesia, and monitored anesthesia care). Cutaneous creams like eutectic mixture of local anesthesia (EMLA) whether used alone or in combination with oral NSAIDS have also been used and are able to reduce analgesic requirements. Topical application of a combination of dimethyl sulfoxide and lidocaine has also been found to be effective.

Conclusion

The ideal analgesic, offering optimal pain control, minimal side effects, and cost-effectiveness is still elusive. Opioids administered using various techniques, provide effective analgesia, but require active monitoring of patient for potential adverse effects. Combination therapy (oral NSAID and occlusive dressing of EMLA, DMSO with lidocaine) offers an effective alternative mode for achieving analgesia with minimal morbidity. This therapy avoids the need for general anesthesia, injectable analgesics, and opioids along with their side effects.

Ureteroscopy during pregnancy

Urolithiasis during pregnancy is an uncommon, but a serious medical problem. Options for the treatment of pregnant women with obstructing stones include ureteral stent placement, percutaneous nephrostomy tube placement, and ureteroscopic stone removal (URS). Although ureteral stent and nephrostomy tube placement have been the historically standard treatment option for pregnant women with obstructing stones, there is an emerging collection of literature that reviews the safety of URS for pregnant women. We performed a systematic review of MEDLINE and EMBASE from January 1966 through April 2009 to identify all literature on URS in pregnant women. Herein, we review the literature on URS during pregnancy, with a focus on the safety of this approach. We conclude that URS is an appropriate intervention in the pregnant population with urolithiasis; in all cases the procedure should be performed on a properly selected patient by a surgeon with appropriate experience and equipment. With such an approach, complication rates are low and success rates are high. A multidisciplinary approach should be emphasized as a key to a successful outcome.