Ureteral wall thickness is an independent parameter affecting the success of extracorporeal shock wave lithotripsy treatment in ureteral stones above the iliac crest

BACKGROUND

To investigate the relationship between ureteral wall thickness (UWT) and other variables of patients who underwent extracorporeal shock wave lithotripsy (SWL) in the primary treatment of the ureteral stone above the iliac crest level.

MATERIAL AND METHODS

A total of 147 patients aged 18 years and older, who underwent SWL in our clinic between December 2016 and December 2019 for the treatment of ureteral stones above the iliac crest level and had non-contrast enhanced abdominal computed tomography scans before the procedure were included in the clinical study. The results were evaluated at 3 months after SWL. The absence of residual fragments was considered as stone-free status, and the existence of any size residual fragment was considered as treatment failure.

RESULTS

In our study, the mean age of the patients was 42.4 ± 12.8 years, and the stone-free rate was 92.5%. The median transverse stone size was 7.5 mm (min 2.8-max 15), and the median UWT was 4.2 mm (1-8.7). In the multivariate analysis, UWT (P = .002) and multiple stone presence (P = .027) were found to be independent factors affecting stone-free status. In the receiver operating characteristic curve analysis, the optimal threshold value for UWT was determined as 5.25 mm.

CONCLUSIONS

We found that UWT was the most important independent variable associated with increased failure in SWL treatment. The presence of multiple stones was another independent factor that increased the failure rates. Using SWL technology through experience accumulated with the mechanical hardware of the machine, we can select patients who are more suitable for this treatment and improve treatment outcomes.

Does Previous Open Stone Surgery Affect the Outcome of Shock Wave Lithotripsy Treatment in Children?

INTRODUCTION

The aim of the study was to evaluate the efficiency of shock wave lithotripsy (SWL) in children who previously underwent ipsilateral open renal stone surgery (ORSS).

METHODS

A total of 315 renal units (RUs) with renal stones underwent SWL treatment in our department over a period of 18 years. A total of 274 RUs (87%) with no history of ORSS were categorized as group 1 and 41 RUs (13%) with a history of ORSS were categorized as group 2. The characteristics of the patients and renal stones, as well as the treatment modalities, were reviewed retrospectively, and the results were compared in terms of the rates of stone-free patients and complications.

RESULTS

The stone-free rates were statistically lower in patients with an existing history of ORSS (p = 0.002), especially for stones located at the lower calyx (p = 0.006). However, there were no differences between groups in the rate of complications (p = 0.75). History of ipsilateral ORSS, age, and stone burden were independent risk factors that predicted a stone-free status in the regression analysis (p = 0.016, p = 0.045, and p = 0.001, respectively).

CONCLUSION

The overall stone-free rate after SWL was found to be significantly lower in children with a history of ORSS than in those without, and this finding was significantly prominent for lower calyx stones. In spite of the possible difficulties in achieving surgical access due to anatomical changes in retrograde intrarenal surgery or mini-/micro-percutaneous nephrolithotomy, we believe that these techniques might be good alternatives for SWL in future cases.

Does Previous Open Renal Stone Surgery Affect the Outcome of Extracorporeal Shockwave Lithotripsy Treatment in Adults with Renal Stones?

PURPOSE

To evaluate the effects of previous ipsilateral open renal stone surgery (ORSS) on outcomes of extracorporeal shockwave lithotripsy (SWL) in adults with renal stones.

MATERIALS AND METHODS

A total of 2097 renal units with renal stones underwent SWL treatment at our institution between March 1997 and February 2013. One thousand eight hundred thirty-nine (87.7%) of these had no history of ORSS and were categorized as group 1, and 258 (12.3%) patients having history of ipsilateral ORSS were categorized as group 2. Characteristics of patients, stone and treatment, stone-free, and complications rates were documented in detail and compared in each group. These groups were also subclassified into four subgroups according to the stone location.

RESULTS

The stone-free rates were statistically higher in group 1 than group 2 (73.2% and 61.6%, respectively). There were no differences between groups regarding the complications and steinstrasse. The stone-free rate of SWL for stones located at lower calix has significant difference according to groups 1 and 2 (64% vs 48.4%, p = 0.001). Logistic regression analysis showed that history of ORSS increased SWL failure rate 1.39 times.

CONCLUSION

Overall stone-free rates after SWL treatment was found to be significantly lower in patients with the history of ORSS than in patients without, and this finding was significantly prominent for lower calix stones. We believe that retrograde intrarenal surgery or mini- /micro-percutaneous nephrolithotripsy, despite its possible difficulties in accessing due to anatomical changes, might be a good alternative for SWL.

Does ureteral stenting matter for stone size? A retrospectıve analyses of 1361 extracorporeal shock wave lithotripsy patients

Introduction

The aim of our study was to determine the efficacy of ureteral stents for extracorporeal shock wave lithotripsy (SWL) treatment of pelvis renalis stones and to compare the results and complications in stented and non-stented patients.

Material and methods

Between 1995 and 2011, 1361 patients with pelvis renalis stones were treated with SWL. Patients were subdivided into three groups according to stone burden: ≤1 cm² (group 1; n = 514), 1.1 to 2 cm² (group 2; n = 530) and >2 cm² (group 3; n = 317). Each group was divided into subgroups of patients who did and did not undergo ureteral stent implantation before SWL treatment. The efficacy of treatment was evaluated by determining the effectiveness quotient (EQ). Statistical analysis was performed by chi-square, Fisher's exact and Mann-Whitney U tests.

Results

Of the 514, 530 and 317 patients in groups 1, 2 and 3 respectively, 30 (6%), 44 (8%) and 104 (33%) patients underwent auxiliary stent implantation. Steinstrasse rates did not differ significantly between stented and non-stented patients in each group. The EQ was calculated as 62%, 33% and 70% respectively in non-stented, stented and totally for group 1. This ratio calculated as 58%, 25% and 63% for group 2 and 62%, 26% and 47% for group 3. Stone-free rates were significantly higher for non-stented than for stented patients in groups 2 and 3.

Conclusions

Stone free rates are significantly higher in non-stented than in stented patients with pelvis renalis stones >1 cm², whereas steinstrasse rates are not affected.

What changed in the management of pediatric stones after the introduction of minimally invasive procedures? A single-center experience over 24 years

OBJECTIVE

To assess the impact of new technology on the management of pediatric urolithiasis by analyzing our local practice over the past 24 years, and determining the role of open surgery at the present time.

METHODS

We retrospectively reviewed the charts of 768 children (783 procedures) who underwent surgical treatment for urolithiasis between June 1987 and October 2010. Data were analyzed with respect to patient characteristics and changing patterns of treatment with time. We compared the type of procedures performed between four time periods: the first was before ESWL, the second was after the introduction of ESWL, the third was after introduction of PCNL, and the fourth was our experienced period with a pediatric urologist.

RESULTS

The mean age of the children was 7.50 years (range 9 months-17 years). There were 495 renal, 228 ureteral, 21 bladder, 11 urethral stones, and the remaining 13 had stones in multiple locations. Of the 783 procedures performed, 75.9% were open surgery during the first period (1987-1992), 29.7% during the second period (1993-1998), 6.1% during the third period (1999-2004) and 0.2% during the fourth period (2005-2010). The number of children who underwent urinary stone treatment increased significantly (p = 0.001) and the age of the children at the time of surgery decreased (9.09-6.08 years) (p = 0.001) with time.

CONCLUSION

The majority of stones in children can be managed using endourological procedures. Additionally, technological advances and improved surgical skills have greatly reduced the number of children requiring open surgery, which is mainly used for those with complex urinary calculi presenting with anatomic abnormalities. Minimally invasive techniques allow us to treat stones at an earlier age.

Predictive factors and management of steinstrasse after shock wave lithotripsy in pediatric urolithiasis--a multivariate analysis study

OBJECTIVE

To define the predictive factors for the formation of steinstrasse (SS) after shock wave lithotripsy (SWL) and determine the treatment strategies for this complication in pediatric urolithiasis.

METHODS

We retrospectively reviewed the data of 341 renal units (RUs) treated with SWL for urolithiasis. The stone location, stone burden, auxiliary procedures, energy level, and number of shock waves were recorded. Statistical analysis was performed to detect the predictive factors for the formation of SS. In addition, the treatment of children with SS was evaluated.

RESULTS

The mean age of the children was 8.31 years (range 1-17). Episodes of SS developed in 26 RUs (7.6%). Of the 26 RUs, 20 (77%) were localized in the lower, 5 (19%) in the upper, and 1 (4%) in multiple locations in the ureter. The stone burden was the only statistically significant factor predicting the formation of SS on logistic regression analysis (P = .001). Of the 26 RUs, 17 (65.4%) were successfully managed by repeat SWL monotherapy, 4 (15.4%) were managed with ureteroscopy after failure of SWL, 1 (3.8%) was managed by ureteroscopy monotherapy, and 4 (15.4%) were monitored with conservative management with antispasmodic drug plus hydration therapy. The mean number of SWL sessions was 1.72.

CONCLUSION

The incidence of SS development in children after SWL treatment was similar to that in adult series. Our results suggest that the stone burden is a significant predictive factor for the development of SS after SWL in pediatric urolithiasis. Most children with SS could be easily and safely treated by repeat SWL.

Tablets of the potassium citrate may cause a stone-like image: a case report

An 8-year-old girl with left proximal ureteral stone (4 mm) was referred to our hospital to treat with shock wave lithotripsy (SWL). Fifteen days after the first SWL session, a plain film of kidneys, ureters and bladder (KUB) demonstrated a new stone-like opacity (10 mm) on the left kidney location other than previous stone of 4 mm. We counseled with her parents and learned that she took a potassium citrate tablet 2 h before. Potassium citrate is a radio-opaque drug and may cause a stone-like image during the stone management. Urologists should consider this particularity of potassium citrate in patients using this drug to avoid unnecessary interventions. To our knowledge, this is the first case in the literature.

Evaluation of the effects of relationships between main spatial lower pole calyceal anatomic factors on the success of shock-wave lithotripsy in patients with lower pole kidney stones

OBJECTIVES

To evaluate the effects of lower pole calyceal anatomy on lower pole stone clearance after shock-wave lithotripsy (SWL).

METHODS

A total of 133 patients who had single lower pole radio-opaque stones treated with SWL alone and who became stone-free or had clinically insignificant residual fragments (CIRF) were included in the study. Pre-shock-wave lithotripsy intravenous urograms were used to determine the lower pole infundibular width and length, lower pole infundibulopelvic (LPIP) angle, caliceal pelvic height (CPH), and lower infundibular length-to-width ratio. In addition, to evaluate the relationship between LPIP and CPH, a more simple alternative measurement instead of LPIP angle, called the parenchyma-to-ureter distance (PUD), was suggested. The correlation between LPIP and PUD was then examined, and a good correlation was found between these values (P <0.000, r = 0.64). The PUD/CPH ratio was also calculated.

RESULTS

The stone-free rate was 62%. According to the cutoff points, the lower infundibular length-to-width ratio and PUD/CPH ratio were different in the stone-free and CIRF groups by univariate analysis but not by multivariate analysis.

CONCLUSIONS

None of the anatomic factors had a statistically significant effect in predicting the success of SWL in patients with lower pole stones. Nevertheless, evaluation of relationships between lower pole anatomic factors may offer some help in reaching a more accurate interpretation of lower pole stone clearance after SWL.

Efficacy of extracorporeal shock wave lithotripsy for isolated lower caliceal stones in children compared with stones in other renal locations

OBJECTIVES

To evaluate the efficacy of extracorporeal shock wave lithotripsy (ESWL) monotherapy for isolated lower caliceal calculi in a pediatric age group and compare it with that for isolated middle/upper caliceal and renal pelvic calculi.

METHODS

We retrospectively reviewed the data of 151 renal units in 126 children treated with ESWL for isolated caliceal and renal pelvic stones from March 1992 to February 2004. The stones were localized in the lower, middle/upper calices, and renal pelvis in 50, 26, and 75 renal units, respectively. The results were compared with respect to renal location and stone burden.

RESULTS

The median patient age was 8 years (range 1 to 16). The median stone burden in the lower and middle/upper caliceal groups was significantly lower than in the renal pelvis group at 0.6, 0.6, and 1 cm2, respectively (P = 0.002). The overall stone-free rate was 62% for lower calices, 65.3% for middle/upper calices, and 80% for renal pelvis stones. For the group with a stone size greater than 2 cm2, the stone-free rate decreased to 33% in both lower and middle/upper calices; however, it was almost the same in the renal pelvis (81.8%). A highly significant relation was found between the stone burden and number of sessions (P < 0.001), but none between the stone burden and stone-free rate.

CONCLUSIONS

In our study, ESWL was equally effective for stones in all locations. We recommend ESWL as the primary treatment of choice for stones less than 2.0 cm2 in all caliceal locations. For the management of caliceal stones greater than 2.0 cm2, prospective randomized trials comparing ESWL and percutaneous nephrolithotomy are necessary.

THE IMPACT OF CALICEAL PELVIC ANATOMY ON STONE CLEARANCE AFTER SHOCK WAVE LITHOTRIPSY FOR PEDIATRIC LOWER POLE STONES

PURPOSE

The clearance rather than stone disintegration of lower pole stones after shock wave lithotripsy (SWL) is significantly inferior according to the other localizations of the kidney. We retrospectively evaluated the impact of caliceal pelvic anatomy on stone clearance after SWL for pediatric lower pole stones.

MATERIALS AND METHODS

We treated 163 renal units (RUs) in children 16 years old or younger with SWL between March 1992 and February 2002. In 36 RUs stones were localized in the lower calices. All patients were treated with sedoanalgesia except 3 (8%) who were treated under general anesthesia. Patients were evaluated by excretory urography and ultrasonography 12 weeks after the last session, and were designated as stone-free or with residual stone. The lower infundibular length, width, length-to-width ratio, pelvic caliceal height and lower infundibulopelvic angle were determined on standard excretory urography before SWL. All measurements were done by 1 urologist who was unaware of the results. Statistical analysis was performed with chi-square, Fisher's exact and Mann-Whitney U tests. ROC analysis was done to determine the cutoff points of caliceal anatomy measurements for stone clearance.

RESULTS

We treated 36 RUs in 23 males and 10 females with isolated lower caliceal stones. Median patient age was 10.5 years (range 2 to 16). Median stone burden was 0.7 cm (range 0.2 to 4), and median number of shock waves and energy used for the entire patient population was 1,500 and 17.2 kV, respectively. Overall stone-free rates for the 36 RUs were 61% after a median treatment session of 1 (range 1 to 7) and retreatment rates were 39%. Of the patients rendered free of stones 13 (59%) were treated in a single SWL session and 9 (41%) underwent 2 or more sessions. Median lower infundibular length, width, length-to-width ratio and pelvic caliceal height in the stone-free and residual stone group were 25.5, 28.0 mm, 4.5, 5.0 mm, 6.4, 5.5 mm and 21.5, 21.5 mm, respectively (p = 0.810, 0.327, 0.511 and 0.511). Median lower infundibulopelvic angle in the stone-free and residual stone groups was 92.50 and 92.50 degrees, and 60.0 and 54.50 degrees, respectively (p = 0.860 and 0.089). On ROC analysis no parameter predicting stone-free rate and cutoff points of caliceal anatomy measurements for stone clearance was found.

CONCLUSIONS

Our results suggest that caliceal pelvic anatomy in pediatric lower pole stones has no significant impact on stone clearance after SWL. There was a highly significant relation between retreatment rates and stone burden, which should be considered for determining the treatment modality.

A Simple Position to Provide Better Imaging of Upper Ureteral Stones Close to the Crista Iliaca during Extracorporeal Shock Wave Lithotripsy Using the Siemens Lithostar

OBJECTIVE

The fluoroscopic image from the second plan (oblique) tube of an upper ureteral stone close to the crista iliaca may be superimposed on the pelvic bones during SWL using the Siemens Lithostar with the patient in the prone position. This creates difficulty in imaging and targeting of the stone and can necessitate using ureteral catheters before treatment and/or intravenous contrast injection during SWL. We describe a very simple, yet effective method for easier visualization of the stone under this circumstance.

METHODS

Between March 1992 and February 2003, we treated 1561 patients with ureteral stones by SWL with the Siemens Lithostar. The stones were localized in the upper ureter in 841. The image of the stone from the second plan (oblique) tube was superimposed on the pelvic bones in 221 in whom visualization of the stone was hardly possible with the standard prone position. By simply rotating the patient 180 degrees on the table, the superimposition of the image of the stone on the pelvic bone was obviated. This resulted in easier and better imaging of the stone during SWL. It also allowed for a clear and superior image to the treating physician during SWL. The energy and shock waves, utilization of anesthesia, number of treatment sessions, auxiliary measures, and complications were noted. Stone load was recorded in square centimeters (cm(2)). Patients were evaluated by intravenous urogram or KUB and ultrasonography when stone-free or CIRF (nonobstructive and noninfectious insignificant fragments < or =4mm) status was noted at the fluoroscopic control 2 to 4 weeks after the last session. Final CIRF decision was made 10-12 weeks after the last session. SWL was regarded as failure if no fragmentation was noted after the 3rd session. Therapy was continued if fragmentation was noted.

RESULTS

The median age was 40 (range 5-85). The mean stone burden was 0.8 (range 0.24-2.9) cm(2). No indwelling ureteral stents were placed in any patients before and during treatment. The mean number of shock waves and energy used for the entire patient population was 2007 and 17.5kV, respectively. The median and average treatment session was 1 and 1.7, respectively. A total of 196 patients (89%) were rendered stone-free. Clinically insignificant residual fragments were present in 18 (8%). SWL was unsuccessful in 7 (3%) patients. These stones were removed by ureterorenoscopy. Intravenous contrast administration was not used to facilitate stone targeting during SWL. Anesthesia, in the form of analgesic sedation, was used in 7 (3%) patients. We did not observe any complications and adverse effects.

CONCLUSIONS

The technique described hereby does not have an affect on coupling; it only provides a superior image of the stone to the treating physician. We advocate its application in all patients with upper ureteral stones close to the crista iliaca when the fluoroscopic image of the stone from the second plan (oblique) tube is superimposed on pelvic bones during SWL in prone position.

The efficacy of extracorporeal shock wave lithotripsy for isolated lower pole calculi compared with isolated middle and upper caliceal calculi

PURPOSE

We assess the efficacy of extracorporeal shock wave lithotripsy monotherapy for isolated lower pole nephrolithiasis, and compare it to that for isolated middle and upper caliceal calculi.

MATERIALS AND METHODS

We treated 714 renal units in 687 patients with isolated caliceal stones using a Lithostar lithotriptor (Siemens Medical Systems, Erlangen, Germany). The stones were localized in the lower, mid and upper calices in 455, 104 and 128 patients, respectively. Stone load was recorded in cm.2. Patients were stratified into 3 groups based on stone burden. The energy and shock waves, use of anesthesia, number of treatment sessions, auxiliary measures and complications were noted. Patients were evaluated with intravenous urogram or plain film of kidneys, ureters and bladder, and ultrasonography when stone-free, or clinically significant residual fragment status, including nonobstructive and noninfectious insignificant fragments 4 mm. or less, was noted at the fluoroscopic control 2 to 4 weeks after the last session. Final clinically significant residual fragment decision was made 10 to 12 weeks after the last session. Extracorporeal shock wave lithotripsy was considered a failure if no fragmentation was noted after session 3 and continued if fragmentation was noted. Results regarding caliceal localization were compared.

RESULTS

Complete data were available on 591 renal units. Auxiliary procedures were used in 81 (14%) units before treatment. Anesthesia was given to 101 (17%) patients. The mean number of shock waves and energy used were 2,022 and 17.4 kV., respectively. The difference in shock wave, energy and treatment rate among 3 caliceal locations reached statistical significance only for energy delivered to the lower and upper calices. The effectiveness quotient of extracorporeal shock wave lithotripsy was 36%, 46% and 41% for lower, middle and upper pole stone disease, respectively (p = 0.4). There was a highly significant correlation between stone-free and re-treatment rates, and stone burden. The overall stone-free rate was 66%, and 63%, 73% and 71% for lower, middle and upper caliceal stones, respectively (p = 0.1). For the group with stones greater than 2 cm.2 overall stone-free rate decreased to 49%, and 53%, 60% and 23% in lower, middle and upper caliceal locations, respectively. Overall, extracorporeal shock wave lithotripsy monotherapy failed in 46 (7.7%) renal units. Steinstrasse developed in 39 (6.5%) patients who were then treated with repeat lithotripsy.

CONCLUSIONS

Extracorporeal shock wave lithotripsy appears to be successful for management of isolated caliceal stone disease. Treatment efficacy was not significantly different among stones localized in lower, middle and upper poles. We recommend it as the primary treatment of choice for stones less than 2.0 cm.2 in all caliceal locations. Treatment should be individualized for management of caliceal stones greater than 2.0 cm.2 until large prospective randomized trials comparing shock wave lithotripsy and percutaneous nephrolithotomy are available.

Extracorporeal shockwave lithotripsy for stones in abnormal urinary tracts: analysis of results and comparison with normal urinary tracts

PURPOSE

We reviewed our experience with SWL for stones in abnormal urinary tracts and compared the results with those in normal urinary tracts.

PATIENTS AND METHODS

The study group was composed of 2566 renal units (RU) treated on the Siemens Lithostar lithotripter at our SWL unit whose treatment and follow-up at 10 to 12 weeks were completed. Sixty-eight RUs (2.7%) belonged to 52 patients who had congenital upper urinary tract abnormalities. Logistic regression analysis was performed to analyze the impact of age, stone size, location, and the type of abnormality on the outcome of the SWL in the abnormal RU. The student t-, chi-square, and Fisher's exact tests were used for the comparison of stone load, number of treatment sessions, catheter placement, and success rates of the patients with normal and abnormal RU. Results of long-term follow-up for available patients (38 RU; 56%) were also evaluated.

RESULTS

Age, stone load, stone location, and the type of abnormality did not have a statistically significant impact on the outcome of SWL for abnormal RU. The average stone load was 2.1 +/- 2.8 cm2 in the abnormal and 1.4 +/- 1.3 cm2 in the normal RU. Thus, the stone load was significantly higher in the abnormal RU (P < 0.05). In the abnormal group, 56% of the RU became stone free, 37% had nonobstructive and noninfectious clinically insignificant residual fragments < or = 4 mm (CIRF), and SWL failed in 7%. In the normal group, 78% of the RU became stone-free, 18.5% had CIRF, and SWL failed in 4%. There was no significant difference in the success rates in the groups if success was defined as stone free and CIRF together (P > 0.05). However, there was significant a difference when stone-free, CIRF, and failure rates were evaluated separately (P < 0.05). Recurrence, regrowth, and retreatment rates in abnormal RU were 50%, 37%, and 34%, respectively.

CONCLUSIONS

Although the fragmentation rates were similar, clearance of the fragments was hampered in abnormal urinary tracts. Thus, especially for large stones, other endourologic treatment options should be considered. High recurrence and regrowth rates warrant careful monitoring and consideration for medical treatment during follow-up.

Extracorporeal shockwave lithotripsy in the pediatric population

BACKGROUND

Shockwave lithotripsy (SWL) is being used increasingly as a therapeutic modality for childhood urolithiasis. We reported our experience and results of SWL in the pediatric population.

METHODS

The 59 renal units (RU) of 54 patients were retrospectively reviewed. The mean patient age was 10+/-3.5 years. All patients were treated with the Lithostar lithotripter in outpatient settings. Those with positive culture results were treated under appropriate antibiotic coverage. Seven patients were treated under general anesthesia and the rest under sedoanalgesia. Shielding of the lung fields or gonads was not used. For the upper pole stones, protection of the lungs was accomplished by elevating the upper half of the body with supportive pillows, thus moving the kidney away from the lung fields. Six RUs were catheterized via double-pigtail ureteral catheters or by percutaneous nephrostomy tube prior to treatment. The average stone load was 1.8+/-2.5 cm2.

RESULTS

Patients were treated with an average of 2.5 sessions. A total of 1000 to 2500 shockwaves were delivered between 14.5 and 17.8 kV. Routine spasmolytic treatment was not initiated. The stone-free rate was 64%, and clinically insignificant residual fragments (CIRF) were present in 29% of RUs; thus, the success rate was 93%. Fever that necessitated hospitalization occurred in one patient. No other complications were seen except skin bruising and early hematuria.

CONCLUSION

Shockwave lithotripsy is a safe and effective treatment modality for childhood stones of appropriate size and radiologic characteristics.