Treatment of ureteral calculi with extracorporeal shock wave lithotripsy using the Lithostar device

Shock wave requirements for fragmentation and the ultimate outcome after extracorporeal shock wave lithotripsy (ESWL) with the Lithostar device were analyzed in 107 renal units with solitary ureteral calculi. In situ treatment was done in 54 stones without prior manipulation and in 15 after failure of endoscopic manipulation. A total of 25 ureteral calculi was treated after bypass with a ureteral catheter or stent and 13 after push back to the pelvicaliceal system. Shock wave requirement for fragmentation was significantly higher for calculi of 101 to 400 mm. X mm. when compared with the requirement for smaller calculi. Shock wave requirement was also significantly higher for patients with similar sized stones treated in the prone compared to the supine position. The average number of shock waves required for disintegration was not significantly different among in situ or any of the manipulation categories of similar sized stone populations. Over-all satisfactory clearance was achieved in 77.5% of the treated ureteral calculi. Clearance status was unaffected by size up to 400 mm. X mm. and the position of the patient during treatment (prone or supine). Clearance of ureteral stones treated in situ without prior manipulation (76.5%) was numerically inferior, although statistically insignificant, to that for successfully manipulated calculi (bypassed 88% and pushed back 92.3%) but it was significantly better than the outcome obtained after failed manipulation (46.2%). ESWL with the Lithostar device is a successful mode of treatment within the entire ureteral length, and a vigorous attempt at push back before lithotripsy is unnecessary.     

A modified algorithm for the management of ureteral calculi: 100 consecutive cases

We treated 100 consecutive ureteral calculi requiring intervention with a previously described algorithm. There were 16 ureteropelvic junction, and 18 upper, 22 mid and 44 lower ureteral calculi. Treatment was by a stent and extracorporeal shock wave lithotripsy in 10 ureteropelvic junction, 10 upper ureteral and 3 mid ureteral calculi, ureteroscopy and extracorporeal shock wave lithotripsy in 6 upper and 6 mid ureteral calculi, and ureteroscopy alone in 5 ureteropelvic junction, 2 upper and 12 mid ureteral calculi. All 44 lower ureteral calculi were treated successfully by ureteroscopy. Of the 100 patients studied 98 were treated by endourological methods (extracorporeal shock wave lithotripsy or ureteroscopy), while 2 required an operation (1 with a ureteropelvic junction calculus and 1 with a mid ureteral calculus). Over-all, 100 patients required a total of 125 procedures to accomplish successful stone removal. An algorithm is developed in which lower ureteral calculi are treated by ureteroscopy, mid ureteral calculi (large and dense) by stent bypass and extracorporeal shock wave lithotripsy or (lucent and fragile) by ureteroscopy, upper ureteral calculi by stent bypass and extracorporeal shock wave lithotripsy without manipulation, and impacted ureteral stones initially by ureteroscopy and, if necessary, then by extracorporeal shock wave lithotripsy.     

输尿管结石气压弹道碎石术与体外冲击波碎石术疗效比较

目的：比较输尿管结石气压弹道碎石术与体外冲击波碎石术的疗效。方法：回顾分析130例气压弹碎石术与1600例体外冲击波碎石术的的碎石率、结石排净率、平均结石排净时间及并发症发生率。结果：气压弹道碎石术碎石率、结石排净率均大于体外冲击波碎石术，平均结石排出时间小于体外冲击波碎石术，并发症发生率两组问无明显差异。结论：输尿管结石行气压弹道碎石术优于体外冲击波碎石术。     

First experience with a modified Siemens Lithostar shock wave system.

A Siemens Lithostar shock wave system was modified and investigated clinically. The modified system yields increased focal pressure and energy density. The first clinical experience in renal calculi shows a significant reduction in shock wave numbers per treatment. Higher energy output enables better treatment results for difficult stones such as staghorn and infections calculi. Despite the higher energy output more than 90% of treatments could be performed without anesthesia or analgesia. No significant side effects could be detected. The service life of the modified shock wave system increased by a factor of two.     

Intracorporeal Lithotripsy with the Swiss Lithoclast

Background: In addition to currently available modalities of intracorporeal lithotripsy (ultrasonic, electrohydraulic, and laser), a new ballistic lithotriptor known as the Swiss Lithoclast has recently gained attention. This study reports our experience with the Swiss Lithoclast in the endoscopic management of urinary calculi.
Methods: A total of 51 patients with urinary calculi were treated with the Swiss Lithoclast; one patient with a renal calculus, 28 with ureteral calculi, and 22 with lower urinary tract (bladder, urethra and Kock pouch) calculi.
Results: The Lithoclast successfully fragmented 94% of the calculi, independent of stone composition. Complete failure of fragmentation was not encountered. In six of the 10 upper ureteral calculi, stone fragments were pushed up into the calyces. Adjunctive extracorporeal shock wave lithotripsy for residual fragments was performed in six cases. The stone-free rate at one and three months was 84% and 88%, respectively. There were no intraoperative or long-term complications directly related to the use of this device.
Conclusion: The Swiss Lithoclast is a safe and effective means of intracorporeal lithotripsy. Although suitable for mid and lower ureteral stones, the device has a risk of stone push-up in patients with upper ureteral stones.     

The use of shock wave lithotripsy for renal calculi

PURPOSE OF REVIEW: Shock wave lithotripsy has been considered a mainstay of therapy for renal calculi for the last 20 years. Shock wave lithotripsy is noninvasive and requires the least anesthesia of the treatment modalities for treatment of renal calculi and therein lies its popularity. In the last decade, however, there have been changes in thinking regarding methods of patient selection for shock wave lithotripsy, changes in the technique of the existing shock wave lithotriptors and new technologies designed to increase the efficacy of shock wave lithotriptors. RECENT FINDINGS: New studies have shown that shock wave lithotripsy may be less effective than other modalities for treating lower pole stones. Other existing technologies, such as computerized tomography, are being used to more effectively select patients for shock wave lithotripsy. Ongoing studies are evaluating changing the shock wave rate to increase stone fragmentation. In addition, efforts are being made to improve lithotripsy by designing more effective lithotriptors. SUMMARY: Shock wave lithotripsy has become a widely used modality for treating renal calculi due to its noninvasive nature and ease of application. Although success rates are reasonable, there is room for improvement. With appropriate patient selection, significant improvements in stone-free rates may be achieved. It is anticipated that, with further research, improvements in lithotriptor design will result in higher treatment success rates with reduced renal trauma and improved patient comfort.     

The influence of electrode shape on the performance of electrohydraulic lithotripters

This study was performed to determine the advantages and disadvantages of the two shapes of electrodes (flat and conical) commonly used in electrohydraulic extracorporeal shock wave lithotripters. Hundreds of measurements made on profiles obtained from a piezoelectric pressure gauge in an underwater shock wave research device showed that conical electrodes are more convenient than flat electrodes, since they produce shock waves with larger compressional amplitudes, less misfires and a better reproducibility, having similar widths and rise times. In an attempt to improve the effectiveness and duration of the electrode tips, a new shape was designed that proved to be more reliable and suitable for lithotripsy than the conventional flat or conical electrodes. Experiments with calculi models placed in the focal region of the shock wave generator seem to confirm the results obtained from pressure measurements.     

Extracorporeal shock wave lithotripsy in children: Results and short-term complications

AIM: The introduction of extracorporeal shock wave lithotripsy represented an important evolution in urinary tract lithiasis management. The aim of this study is to describe the results of extracorporeal shock wave lithotripsy for the treatment of urinary tract lithiasis in children, focusing on the index of elimination of the calculi and the complications occurring during the procedure and during the following three months. METHODS: From September 1991 to July 2002, 135 children between one and 12 years, suffering from urinary tract lithiasis underwent extracorporeal shock wave lithotripsy. A retrospective analysis of these patients was carried out. RESULTS: One hundred and ninety-five calculi ranging in size from 5.0 mm to 20.0 mm were treated, out of which 147 were found in the kidneys and 48 in the ureter. Urinary tract dilation was presented by 30% of the children at the time of the procedure. After extracorporeal shock wave lithotripsy 75.8% of the calculi were eliminated: 64.1% were stone-free and 11.7% had < or = 4 mm stones. Ureteral calculi and 5-10 mm stones responded better than the kidney and 11-20 mm stones (P = 0.027 and P = 0.012, respectively). No differences were detected according to the calculi location, whether in the ureter or kidney (P = 0.637 and P = 0.703, respectively). The shock wave intensity of 14kv was as efficient as the higher voltage. Short-term complications were observed in 23.7%, characterized by fever and pain. CONCLUSION: In children, extracorporeal shock wave lithotripsy proved to be able to eliminate 75.8% of the treated calculi and 83.7% of the patients presented a complete or partial response. Complications were observed in 23.7% of patients, and pain was the most frequent symptom.     

Extracorporeal shock wave lithotripsy treatment of calculi in horseshoe kidneys

From June 1985 to November 1986, 17 patients with calculi in horseshoe kidneys presented to our hospital for evaluation and possible treatment with extracorporeal shock wave lithotripsy. Of these patients 14 were treated with extracorporeal shock wave lithotripsy; the calculi in 2 could not be localized and focused at the F2 focal point, and 1 was asymptomatic and has been followed conservatively. Four patients required repeat extracorporeal shock wave lithotripsy. Adjunctive procedures included preoperative retrograde catheter placement (5 patients), postoperative percutaneous nephrostolithotomy (1), ureteroscopy for ureteral fragments (2) and placement of a double pigtail stent (1). Of 14 patients 11 (79 per cent) have been rendered free of fragments with extracorporeal shock wave lithotripsy and adjunctive measures as needed. We conclude that most patients with calculi in a horseshoe kidney can be managed primarily with extracorporeal shock wave lithotripsy.     

Extracorporeal shock wave lithotripsy for the treatment of bulbous urethral stones

Extracorporeal shock wave lithotripsy was used to treat multiple, large, bulbous urethral calculi in a paraplegic man. Prior attempt at endoscopic extraction was unsuccessful owing to the size and location of the calculi. Two treatments of 3,000 shocks each resulted in fragmentation of the calculi     

Multimodality treatment of complex renal calculi

More than 2,500 patients were treated for urolithiasis from 1984 to 1987. In an effort to define the relative role of extracorporeal shock wave lithotripsy and percutaneous nephrolithotomy with respect to size, location and composition of the calculus 912 of these patients (224 of whom underwent percutaneous nephrolithotomy and 688 of whom underwent extracorporeal shock wave lithotripsy) were reviewed. Size proved to be the only significant factor in the success and complication rates of extracorporeal shock wave lithotripsy but it did not affect the outcome of percutaneous nephrolithotomy. The roles of these 2 modalities were then examined with respect to the treatment of complex renal calculi. We reviewed 376 patients with complex renal calculi, including 40 percutaneous nephrolithotomy patients from the initial 912 patients studied. The initial therapy in 100 of these patients, treated consecutively, was extracorporeal shock wave lithotripsy. The remaining 276 patients were treated by percutaneous nephrolithotomy. The success rate of extracorporeal shock wave lithotripsy monotherapy in the treatment of complex renal calculi was 36%. The success rate of primary percutaneous nephrolithotomy was 83%. We conclude that percutaneous nephrolithotomy should be the primary therapy for patients with complex renal calculi. Extracorporeal shock wave lithotripsy is the preferred treatment for patients with smaller calculi and as an adjunct to percutaneous nephrolithotomy.     

Experience with ultrasound-guided ESWL

The ESWL treatment of gallstones has led to the development of ultrasound-guided lithotripters. The interdisciplinary use of these new ESWL systems by urologists, general surgeons and gastroenterologists means that different requirements have to be met. As a result of this development, ultrasound in urology is gaining even more significance. While ESWL treatment of renal calculi under ultrasound guidance has quickly become a routine method, the in situ treatment of ureteral calculi is much more problematic. In our study the validity of diagnostic ultrasound for the localization of ureteral stones was investigated. In an unselected preliminary series only 30% of ureteral calculi could be located by ultrasound. The success rates were 39% for distal stones and 16% for proximal calculi. The treatment results of renal calculi are on a par with those previously obtained under fluoroscopic guidance. Once exact localization is obtained by ultrasound, disintegration rates for ureteral calculi are fully comparable to those performed under fluoroscopic guidance. However, 60% of ureteral stones can not be located by ultrasound. Therefore, retrograde manipulation and ureteroscopic stone disintegration gains more importance in interdisciplinary shock wave centers equipped with ultrasound-guided machines. A real alternative to second-generation lithotripters in the treatment of ureteral stones will thus only be obtained if an X-ray device can be added to the locating system if necessary. With this combination device the treatment of most ureteral calculi will thus be possible.     

ESWL治疗上尿路结石480例临床分析

目的探讨上尿路结石体外冲击波(ESWL)的治疗效果。方法回顾性分析480例肾及输尿管结石患者行ESWL治疗的效果。结果 ESWL治疗1～3次结石粉碎并排净者473例,治愈率(98.5%)。7例(1.5%)ESWL治疗无效改行输尿管镜或外科手术治疗。结论体外冲击波碎石对于治疗肾及输尿管结石效果满意。     

Electromagnetic extracorporeal shock wave lithotripsy in children

Extracorporeal shock wave lithotripsy (ESWL) was performed for the treatment of urinary tract calculi in 28 children. All treatments were done with the standard Siemens Lithostar device in situ: no special adaptations for adequate positioning of children are required to target the stone precisely. A total of 42 calculi in 30 renal units was treated, requiring 50 ESWL sessions. The mean energy used was 16.4 kv. and the number of shock waves averaged 3,188. Mean fluoroscopy time per session was 1.5 minutes. In 26 of 50 sessions (52%) general anesthesia was needed for the child to remain perfectly still. A complete stone-free rate was achieved in 38 of 42 calculi (90.5%): after 1 session in 30 (71.4%), after 2 sessions in 6 (13.7%) and after 3 sessions in 2 (4.8%). Five staghorn calculi were treated with ESWL monotherapy. A complete stone-free result was obtained after 3 treatments in 2 patients, while 2 had residual fragments in the lower pole (5 mm. after 6 sessions and 11 months of followup in 1, and 7 mm. after 3 sessions and 3 months of followup in 1). A cystine staghorn stone necessitated open nephrolithotomy after 3 sessions without any fragmentation. One impacted sacroiliac ureteral stone required endoscopic laser lithotripsy. Except for these 2 failures no adjuvant procedures were needed. There were no intraoperative or postoperative complications and minor skin bruising at the coupling site after 3 treatments did not require any therapy. We conclude that electromagnetic ESWL with the standard Lithostar unit is a safe and effective method to treat calculi throughout the urinary tract in children.     

Comparison of results and morbidity of percutaneous nephrostolithotomy and extracorporeal shock wave lithotripsy

Two new therapies, percutaneous nephrostolithotomy and extracorporeal shock wave lithotripsy, are revolutionizing the treatment of upper urinary tract calculi. We report the success and morbidity rates in 110 patients undergoing percutaneous nephrostolithotomy and 982 patients treated with extracorporeal shock wave lithotripsy. Staghorn calculi were excluded from this series. The over-all success rate (free of stones plus small asymptomatic residual fragments) was comparable with both modalities (percutaneous nephrostolithotomy 98 per cent and extracorporeal shock wave lithotripsy 95 per cent), although the presence of residual fragments was more common in kidneys treated with extracorporeal shock wave lithotripsy (24 versus 7 per cent). Patient morbidity as measured by temperature elevation, length of postoperative stay, pain and blood loss was significantly less (p less than 0.05) with extracorporeal shock wave lithotripsy than with percutaneous nephrostolithotomy. Re-treatment rates were similar with both procedures, and tended to increase in relation to increasing stone size and stone number. Post-treatment ancillary procedures (cystoscopy and stone manipulation, and percutaneous nephrostomy) were used more frequently with extracorporeal shock wave lithotripsy. Because of its efficacy and low morbidity, we conclude that extracorporeal shock wave lithotripsy is the treatment of choice for upper urinary tract calculi less than 2 cm. in diameter. However, percutaneous nephrostolithotomy will continue to have a primary role in the management of larger stones and cystine stones, and it will be used as a secondary procedure after unsuccessful extracorporeal shock wave lithotripsy treatments. In addition, because of the complimentary nature of these 2 new technologies certain complex stones, such as staghorn calculi, may be handled best by a combination of the 2 techniques.     

体外冲击波碎石治疗儿童尿路结石的疗效观察(附62例报告）

目的：探讨体外冲击波碎石(ESWL)治疗儿童尿路结石的有效性和安全性。方法：采用ESWL治疗儿童尿路结石患者62例，其中肾盂肾盏结石35例，输尿管结石22例，膀胱结石4例，移植肾结石1例。结果：62例随访3个月，结石排净59例(95．2％)，结石残留2例(3．2％)，1例无效(1．6％)，改用手术治疗。结论：ESWL治疗儿童尿路结石安全、有效，是儿童尿路结石的首选治疗方法。     

An evaluation of ureteral laser lithotripsy: 225 consecutive patients

We treated 225 patients with 227 ureteral calculi (5 steinstrasse) via the pulsed dye laser with 9.5F rigid, 7.2F semirigid and flexible, steerable ureteroscopes. The 222 calculi (excluding steinstrasse) were fragmented by laser alone in 141 cases (64%), laser and a basket in 30 (13%), and laser and extracorporeal shock wave lithotripsy in 33 (15%). The laser failed in 18 cases (8%). Of the 222 calculi 165 were impacted. Of 29 impacted upper ureteral calculi 15 were treated by laser disimpaction and fragmentation, 13 by laser disimpaction followed by extracorporeal shock wave lithotripsy and 1 by an operation. Of 42 mid ureteral calculi (30 impacted) 24 were treated successfully by laser fragmentation and 14 by fragmentation followed by extracorporeal shock wave lithotripsy, while 4 failed laser therapy. Among 151 lower ureteral and tunnel calculi laser fragmentation was successful in 132 cases (87%), laser followed by extracorporeal shock wave lithotripsy was successful in 6 and 13 failed laser treatment. There were no ureteral strictures and no ureteral injuries related to use of the laser. The pulsed dye laser is safe and effective treatment for impacted upper and mid ureteral calculi, small mid ureteral calculi in female patients, and lower ureteral calculi in male and female patients. Use of the laser in conjunction with other endourological methods resulted in the need for an operation in 2 of 225 patients (0.9%) with ureteral calculi.     

Nitinol stone retrieval-assisted ureteroscopic management of lower pole renal calculi

Objectives. Current ureteroscopic intracorporeal lithotripsy devices and stone retrieval technology allow for the treatment of calculi located throughout the intrarenal collecting system. Difficulty accessing lower pole calculi, especially when the holmium laser fiber is used, is often encountered. We retrospectively reviewed our experience with cases in which lower pole renal calculi were ureteroscopically managed by holmium laser fragmentation, either in situ or by first displacing the stone into a less dependent position with the aid of a nitinol stone retrieval device.Methods. Thirty-four patients (36 renal units) underwent ureteroscopic treatment of lower pole renal calculi between April 1998 and November 1999. Lower pole stones less than 20 mm were primarily treated by ureteroscopic means in patients who were obese, in patients who had a bleeding diathesis, in patients with stones resistant to shock wave lithotripsy, and in patients with complicated intrarenal anatomy, or as a salvage procedure after failed shock wave lithotripsy. Lower pole calculi were fragmented with a 200-μm holmium laser fiber by way of a 7.5F flexible ureteroscope. For those patients in whom the laser fiber reduced the ureteroscopic deflection, precluding re-entry into the lower pole calix, a 3.2F nitinol basket or a 2.6F nitinol grasper was used to displace the lower pole calculus into a more favorable position, allowing easier fragmentation.Results. In 26 renal units, routine in situ holmium laser fragmentation was successfully performed. In the remaining 10 renal units, a nitinol device was passed into the lower pole, through the ureteroscope, for stone displacement. Only a minimal loss of deflection was seen. Irrigation was significantly reduced by the 3.2F nitinol basket, but improved with the use of the 2.6F nitinol grasper. This factor did not impede stone retrieval in any of the patients. At 3 months, 85% of patients were stone free by intravenous urography or computed tomography.Conclusions. Ureteroscopic management of lower pole calculi is a reasonable alternative to shock wave lithotripsy or percutaneous nephrolithotomy in patients with low-volume stone disease. If the stone cannot be fragmented in situ, nitinol basket or grasper retrieval, through a fully deflected ureteroscope, allows one to reposition the stone into a less dependent position, thus facilitating stone fragmentation.     

The effect of extracorporeal shock wave lithotripsy on the microbiological flora of urinary calculi

To determine whether extracorporeal shock wave lithotripsy can sterilize infection stones and, thus, decrease the recurrence rate we investigated its impact on the microbiological flora of staghorn calculi. Fragments from 17 staghorn calculi retrieved percutaneously were divided into paired sets. One set was fractured by extracorporeal shock wave lithotripsy at 18 kv. and with increasing numbers of shock waves up to 1,000. One set was fractured mechanically with a surgical clamp. Bacterial cultures were then compared between the 2 groups. Of the 17 staghorn calculi 10 showed significant bacterial growth (59%). The number of colony-forming units was not significantly different between stones fragmented by lithotripsy and those that were mechanically fractured. Furthermore, exposing fragments to an increasing number of shock waves did not alter the colony count. We conclude that extracorporeal shock wave lithotripsy has no discernible effect on the microbiological flora of infected staghorn calculi.     

Enhanced kidney stone fragmentation by short delay tandem conventional and modified lithotriptor shock waves: a numerical analysis

PURPOSE: We evaluated the effectiveness of modified lithotriptor shock waves using computer models. MATERIALS AND METHODS: Finite element models were used to simulate the propagation of lithotriptor shock waves in human renal calculi in vivo. Kidney stones were assumed to be spherical, homogeneous, isotropic and linearly elastic, and immersed in a continuum fluid. Single and tandem shock wave pulses modified to intensify the collapse of cavitation bubbles near the stone surface to increase fragmentation efficiency and suppress the expansion of intraluminal bubbles for decreased vascular injury were analyzed. The effectiveness of the modified shock waves was assessed by comparing the states of loading in the renal calculi induced by these shock waves to those produced by conventional shock waves. RESULTS: Our numerical simulations revealed that modified shock waves produced marginally lower stresses in spherical renal calculi than those produced by conventional shock waves. Tandem pulses of conventional or modified shock waves produced peak stresses in the front and back halves of the renal calculi. However, the single shock wave pulses generated significant peak stresses in only the back halves of the renal calculi. CONCLUSIONS: Our numerical simulations suggest that for direct stress wave induced fragmentation modified shock waves should be as effective as conventional shock waves for fragmenting kidney stones. Also, with a small interval of 20 microseconds between the pulses tandem pulse lithotripsy using modified or conventional shock waves could be considerably more effective than single pulse lithotripsy for fragmenting kidney stones.