Outcome and safety of extracorporeal shock wave lithotripsy as first-line therapy of lower pole nephrolithiasis

INTRODUCTION: The aim of this study is to assess the efficiency of extracorporeal shock wave lithotripsy (ESWL) as initial therapy for isolated lower pole kidney stones smaller than 20 mm. PATIENTS AND METHODS: During a 24-month period 116 patients with previously untreated single stones under 20 mm in diameter were treated with a Dornier lithotripter S. They were analyzed with regard to stone site and size, number of ESWL sessions, auxiliary measures, retreatment rates, complications and the time taken for stone clearance. RESULTS: 76 patients (65.5%) became stone free, 50 of them (43.1%) within 3 months after ESWL. Depending on stone size the stone-free rates were 67.1% for patients with a stone diameter of <10 mm (59 of 88 patients), and 60.7% for stone diameters between 10 and 20 mm (17 of 28 patients). Complications during and after treatment were rare, i.e. the necessity of ureteral stent insertion due to colic (n = 10), endoscopic stone removal (n = 2), acute pyelonephritis (n = 1), stonestreet (n = 1) and 1 case of hematoma not requiring intervention. The recurrence rate during follow-up (13.2-36.9, mean 25.0 months) was low: 16 patients (13.8%) had recurrent or persistent stones, and 74 patients (63.8%) had no evidence of urolithiasis. CONCLUSIONS: ESWL is a safe and efficient first-line therapy for treatment of isolated small lower pole kidney stones with acceptable stone-free rates, low morbidity, few complications and a low stone recurrence rate.     

Computerized tomography attenuation value of renal calculus: can it predict successful fragmentation of the calculus by extracorporeal shock wave lithotripsy? A preliminary study

PURPOSE: We evaluated the attenuation value of renal calculi on unenhanced axial computerized tomography (CT) images as a predictor of calculous fragmentation by extracorporeal shockwave lithotripsy (ESWL) (Dornier Medical Systems, Inc., Marietta, Georgia). MATERIALS AND METHODS: We included 30 patients with renal calculi up to 20 mm. in this prospective study. Calculous attenuation value was measured in Hounsfield units on unenhanced CT sections through the calculi. Patients were subsequently treated with ESWL. RESULTS: Patients were grouped according to calculous attenuation value as groups 1-less than 500, 2-500 to 1,000 and 3-greater than 1,000 Hounsfield units. Of the 30 patients 24 (80%) underwent successful treatment. The rate of stone clearance was 100% (12 of 12 cases) in group 1, 85.7% (6 of 7) in group 2 and 54.5% (6 of 11) in group 3. The success rate for stones with an attenuation value of greater than 1,000 Hounsfield units was significantly lower than that for stones with a value of less than 1,000 Hounsfield units (6 of 11 versus 18 of 19 cases, chi-square 7.07, p <0.01). Patients in group 3 required a greater median number of shock waves for stone fragmentation than those in groups 1 and 2 (7,300, 2,500, and 3,390, respectively). The mean attenuation value and number of shock waves required for calculous fragmentation correlated significantly (r = 0.779, p <0.001). CONCLUSIONS: The CT attenuation value of renal calculi can help to differentiate stones that are likely to fragment easily on ESWL from those that would require a greater number of shock waves for fragmentation or may fail to fragment on ESWL.     

体外冲击波碎石成功治疗肾结石的多因素分析

目的 确定病人和结石在非增强螺旋CT上的特点,预言2种体外冲击波碎石后的结果:结石分散状态(游离状态)或体外碎石成功.方法 回顾性分析200个相连续的用体外震波碎石治疗的肾结石患者.患者年龄、性别、结石侧别、体表面积、体重、结石最大容积、结石的平均CT值、结石密度、皮肤到结石距离,肾内结石的位置,研究这些潜在的预测因子.患者非肾脏、输尿管、膀胱手术后钙化,在第6周时拍腹部平片确定结石的分散状态,体外冲击波碎石成功者:结石残留碎片小于4mm.结果 发现肾内结石的位置是唯一一个预测体外碎石后结石分散状态的因子.肾盂、肾盂输尿管交界处结石清除率要高于肾盏结石;上盏或中盏结石清除率要高于下盏.结石大小、平均CT值和结石的位置能够预测体外震波碎石的成功率.小结石和低CT值结石更容易被击碎,在肾盏结石中更高的离散状态和体外碎石的成功率发现与更短的皮肤-结石距离有关,肾盂结石和肾盂输尿管交界处结石排除在分析之外.结论 结石的位置是体外震波碎石后获得结石离散状态最重要的因素,非增强螺旋结石特点:诸如结石大小、平均密度、结石肾内位置是体外震波碎石成功的重要预测因子.

Abstract：

Objectives To determine the patient and noncontrast computed tomography (NCCT) stone characteristics that predict either of 2 extracorporeal shock wave lithotripsy (ESWL) outcomes: stone - free (SF)status or ESWL success. Methods The records of 200 consecutive patients with nephrolithiasis treated with ESWL were reviewed. Patient age, sex, stone laterality, body surface area, body mass index, maximal stone dimension,mean stone Hounsfield units (HU), stone Hounsfield density, skin- to- stone distance (SSD), and intrarenal stone location were studied as potential predictors. Patients with no calcifications on postoperative kidneys, ureters,and bladder (KUB) at 6 weeks were defined as SF. ESWL success was defined as SF or remaining stone fragments less than 4 mm. Results lntrarenal stone location was found to be the only predictor of SF status. Renal pelvic/ureteropelvic junction (UPJ) stones cleared better than calyceal stones, and upper/middle calyceal stones cleared better than lower calyceal stones. Stone size, mean HU, and location predicted ESWL fragmentation success. Smaller stones and stones with lower mean HU levels were more successfully fragmented. Higher SF and ESWL success rates were found with a shorter SSD among calyceal stones when renal pelvic/UPJ stones were excluded from analysis. Conclusions Stone location is the most important factor in achieving SF status after ESWL. NCCT stone characteristics such as stone size, mean HU, and intrarenal location are important predictors of ESWL success.     

Pelvicalyceal stone load: a factor affecting the outcome of extracorporeal shockwave lithotripsy for renal pelvic calculi

OBJECTIVES: To determine the effect of variations in pelvicalyceal volume on the results of extracorporeal shock wave lithotripsy (ESWL) and the relationship of stone load to estimated pelvicalyceal volume in patients with renal pelvic stones. PATIENTS AND METHODS: In all, 204 patients with renal pelvic stones were treated primarily by ESWL. Exclusion criteria were radiolucent stones, dilatation of the renal collecting system, JJ stent insertion before ESWL and an inadequate follow-up. The surface area of the stones and the renal collecting system were measured using a grid of 1 mm2 divisions. The pelvicalyceal volume was calculated as 0.6 (area)1.27. To evaluate the treatment results a pelvicalyceal stone load (PSL) index, describing the relationship of stone load to total estimated pelvicalyceal volume, was defined as stone volume/renal collecting system volume. RESULTS: The mean (range) pelvicalyceal volume of the patients was 13.24 (4.12-28.47) mm3 and the mean PSL index was 26.2%. The cumulative success rates according to the PSL decreased from 97% to 90% with increasing PSL, but remained at > 95% in patients with a PSL index of < 50%. In all, 184 sessions were applied and the session/patient ratio increased from 1.41 to 3.0 with increasing PSL. Complications were acute pyelonephritis in three and steinstrasse in five patients. CONCLUSION: The PSL index appears to be a more accurate and reproducible method for predicting the outcome of ESWL, and has the advantage of considering the effect of pelvicalyceal anatomy.     

Extracorporal shock wave lithotripsy in the management of stones in children with oxalosis—still the first choice?

Background

Primary hyperoxaluria (PH) is a recognised cause of nephrolithiasis. The aim of this study was to evaluate the success of extracorporal shock wave lithotripsy (ESWL) in treating nephrolithiasis in children with PH.

Methods

This was a retrospective review of patient characteristics, treatments and outcomes of 36 children with oxalate stones due to PH.

Results

A total of 52 stones were formed in 28 patients, of which 23 stones were treated with ESWL. Of these 23 stones, ten improved and 13 did not; nine were located in the upper pole, nine in the lower pole and four and one in the pelvic and ureteric areas, respectively. All pelvic and ureteric stones improved, while 66.7 % of upper pole stones and 89.9 % of lower pole stones did not; 20 % of PH type 1 stones improved compared to 47 % of PH type 2 stones. The mean pre- and post-eGFR in stone-improvers was 98.82 and 104.7 ml/min/1.73 m², respectively; in the non-improvers, these values were 100.75 and 95.68 ml/min/1.73 m², respectively. Mean pre-ESWL stone size in the improved and non-improved groups was 7.3 mm and 8.5 mm respectively.

Conclusions

Based on our results, ESWL is not the ideal method of stone therapy for patients with PH. ESWL was more effective in treating pelvic and ureteric stones, with upper pole stone response being better than lower pole response. PH2 patients were more than twice as likely to respond to ESWL treatment. Stone size and prior preventive treatment did not affect outcome. eGFR was not affected by ESWL.     

Evaluation of the results of extracorporeal shock-wave lithotripsy (ESWL) for solitary upper urinary tract stone

At Osaka City University Hospital, we performed extracorporeal shock-wave lithotripsy (ESWL) for 1277 patients in a total of 1788 sessions using Dornier kidney lithotripter Model HM III from July, 1985 to the end of December, 1988. Among the patients with a solitary stone, 911 cases were available for the follow-up study and we have compared the results among these cases in respect to the stone location and size. The results obtained were as follows: the ratio of kidney stone to ureter stone was found to be 2.2:1 in male, and 3.8:1 in female patients. This indicates that ureter stones are more frequently found in male than in female patients. In addition, we compared the size of kidney stones found in the patients including 415 male and 243 female patients. Stones larger than 20 mm were more frequently found in female than in male patients. Moreover, a stone composition study of these patients showed that the contents of both phosphate calcium and magnesium ammonium phosphate were higher in female than in male patients. ESWL performed against stones at pelvis and calyces exhibited the best results. The results obtained with the stones less than 20 mm in diameter were especially favorable with a success rate of 100% for the stones less than 10 mm and 83% for the stones 10-20 mm, in diameter, while the results with the stones larger than 20 mm in diameter were rather poor with a success rate of 31%. ESWL performed against ureter stones showed poor results with a success rate of 63% for the stones smaller than 20 mm in diameter.     

Pelvi-calyceal height, a predictor of success when treating lower pole stones with extracorporeal shockwave lithotripsy

Extra corporeal shockwave lithotripsy (ESWL) is the treatment of choice for the majority of renal stones, however, it has the lowest success rate in complete clearance of stones located in the lower pole. We assess whether pelvi-calyceal height is a useful measurement in predicting successful stone clearance from the lower pole. A total of 105 patients with a solitary lower pole calculus of less than 20 mm treated with ESWL were reviewed. Stone size, location and pelvi-calyceal height were measured by intravenous urogram. Success was defined as complete stone clearance. Fifty-four patients (51.4%) had successful treatments, with the remaining 51 (48.6%) having incomplete stone clearance (including two patients in whom treatment had no effect). There was a statistically significant difference (P<0.0001) in pelvi-calyceal height between the two groups. Mean pelvi-calyceal height in patients with complete stone clearance was 15.1 mm (SD=3.9) compared with 22.9 mm (SD=5.2) for those with incomplete clearance. Pelvi-calyceal height is a useful predictor of success when treating lower pole renal stones with ESWL.     

The fate of residual fragments after extracorporeal shock wave lithotripsy monotherapy of infection stones

We reviewed 53 patients with infection stones treated by extracorporeal shock wave lithotripsy (ESWL*) monotherapy to determine the long-term rate free of stones and the stone recurrence rate as correlated with the pre-treatment stone burden and the radiological presence of sand or fragments after the procedure. Long-term followup (mean 26.6 months) was available on 33 patients representing 38 kidneys. Although only 3 kidneys were free of stones immediately after ESWL, 20 were without stones at 3 months and 18 (47%) were stone-free at followup. Of 9 kidneys with fragments of more than 5 mm. after the final treatment 7 (78%) had residual fragments at 3 months and experienced stone progression. Of 9 kidneys with sand remaining 6 (66%) and all 3 kidneys that appeared to be free of stones after ESWL were without stones at followup. The 3-month plain film of the kidneys, ureters and bladder was a reliable indicator of eventual outcome. Of 20 kidneys that were free of stones at 3 months 16 remained without stones. Of 18 kidneys with residual stone particles at 3 months 14 showed disease progression, 2 had stable disease and 2 passed residual sand. Only 1 of 17 patients who were free of stones or had stable stone disease had a positive urine culture at followup. Patients with infection stone fragments 3 months after ESWL monotherapy have a high rate of stone progression (78%) and should undergo further treatment. ESWL monotherapy of infection stones requires close patient followup to assure that all residual fragments have passed and urine remains sterile.     

Extracorporeal shock wave lithotripsy with EDAP LT-01 lithotriptor

Extracorporeal shock wave lithotripsy (ESWL) by EDAP LT-01 was used to treat 77 patients with upper urinary tract stones. A total of 218 sessions were performed for 111 stones in 52 kidney units and 41 stones in 37 upper ureter units, and 77% of the 52 kidney stone units and 62% of the 37 ureter units were completely disintegrated. The success of fragmentation of kidney stones differed with the size of the stone, 96% of the stones less than 21 mm and 63% of the 8 stones between 21 and 30 mm were successfully fragmented. The success of fragmentation of ureteral stones differed auxiliary manipulation. Eighty-one percent of the 21 ureteral stones moved into the kidney, were successfully disintegrated, but 40% of the 20 stones unmoved could be disintegrated with retrograde manipulation. Of the 62 successful units, 89% became stone free within 3 months. Complications were subcapsular renal hematoma in 3 patients and obstruction in 5 patients. The initial 25 patients were treated under epidural anesthesia and 52 patients were treated without anesthesia. The results show that the indication of ESWL with LT-01 is better for the stones smaller than 30 mm and the indication should be determined after a couple of sessions for stones greater than 30 mm. ESWL with LT-01 can be performed on an out-patient basis without anesthesia in many cases.     

Evaluation of the results of extracorporeal shock-wave lithotripsy (ESWL) for solitary upper urinary tract stone]

We performed extracorporeal shock-wave lithotripsy (ESWL) on 1,701 patients in a total of 2,438 sessions using the Dornier kidney lithotriptor Model HM III from July 1985 to the end of June 1990. Among the patients with a solitary stone, 1,200 cases were available for the follow-up study in which the results of ESWL were analyzed according to the location and size of the stone. ESWL performed against stones at pelvis and calyces gave the best results. The results obtained on stones less than 20 mm in diameter were especially favorable with a success rate of 84%. ESWL performed against ureter stones showed poor results with a success rate of 62% for the stones smaller than 20 mm in diameter. We further studied the results of ESWL performed against ureter stones by dividing the patients into three groups: the patients treated in situ, the patients with ureteral stents and the patients with D-J stents. The results for stones larger than 10 mm in diameter were significantly better in the patients with D-J stents than in the patients treated in situ or the patients with ureteral stents. Among the patients treated in situ, the results were significantly worse for impacted stones than for non-impacted stones when the stone size was 10-20 mm in diameter.     

Calcium stone fragility is predicted by helical CT attenuation values

BACKGROUND AND PURPOSE: Helical CT has become the preferred method for imaging urinary calculi, and so it would be useful if data from helical CT could also be used to predict the number of shockwaves (SWs) needed to break a given stone. METHODS AND MATERIALS: We measured the number of SWs required to comminute calcium stones in vitro. RESULTS: The SW requirement correlated with stone size (volume, weight, diameter) and with helical CT attenuation values when the scans were performed at 3-mm collimation. When CT scans were performed at 1-mm collimation, the number of SWs needed for comminution did not correlate with helical CT attenuation values. This result indicates that the correlation with 3-mm scans was attributable to volume-averaging effects, in which smaller stones yield smaller attenuation values. That is, attenuation values from helical CT at larger beam collimation widths contain information about stone size that can be exploited to predict the fragility of calcium stones. We observed that for calcium stones, the number of SWs to comminution was generally less than half the stone CT attenuation value in Hounsfield units. This "half-attenuation rule" predicted the number of SWs needed to complete fragmentation for 95% of calcium stones (24/24 calcium oxalate monohydrate, 13/13 hydroxyapatite, 8/10 brushite stones). CONCLUSION: This in vitro study suggests that it may be possible to predict effective SW dose using helical CT prior to lithotripsy.     

Flexible ureterorenoscopy versus extracorporeal shock wave lithotripsy for treatment of lower pole stones of 10-20 mm

Study Type – Therapy (case series) Level of Evidence 4 What's known on the subject? and What does the study add? Shock wave lithotripsy and flexible ureterorenoscopy are acceptable treatment options for lower pole stones smaller than 10 mm, while percutaneous nephrolithotomy is the favoured treatment for stones larger than 20 mm. For treatment of lower pole stones of 10–20 mm, flexible ureterorenoscopy has a significantly higher stone‐free rate and lower retreatment rate than shock wave lithotripsy.

OBJECTIVE

• ? To compare the outcomes of flexible ureterorenoscopy (F‐URS) and extracorporeal shock wave lithotripsy (ESWL) for treatment of lower pole stones of 10–20 mm.

PATIENTS AND METHODS

• ? The database of patients with a single lower pole stone of 10–20 mm was examined to obtain two matched groups who were treated with F‐URS or ESWL. Matching criteria were stone length, side and patient gender.
• ? Stone‐free rates were evaluated 3 months after the last treatment session by non‐contrast computed tomography. Both groups were compared for retreatment rate, complications and stone‐free rate.

RESULTS

• ? The matched groups included 37 patients who underwent F‐URS and 62 patients who underwent ESWL. Retreatment rate was significantly higher for ESWL (60% vs 8%, P < 0.001).
• ? Complications were more after F‐URS (13.5% vs 4.8%), but the difference was not significant (P= 0.146). All complications were grade II or IIIa on modified Clavien classification.
• ? The stone‐free rate was significantly better after F‐URS (86.5% vs 67.7%, P= 0.038). One failure of F‐URS (2.7%) and five failures (8%) of ESWL were treated with percutaneous nephrolithotomy.
• ? Significant residual fragments in three patients (8%) after F‐URS were treated with ESWL, while significant residual fragments after ESWL in five patients (8%) were treated with F‐URS. Residual fragments (<4 mm) were followed every 3 months in one patient (2.7%) after F‐URS and in 10 patients (16%) after ESWL.

CONCLUSIONS

• ? For treatment of lower pole stones of 10–20 mm, F‐URS provided significantly higher stone‐free rate and lower retreatment rate compared with ESWL.
• ? The incidence of complications after F‐URS was not significantly more than after ESWL.

     

Efficacy of expulsive therapy using nifedipine or tamsulosin,both associated with ketoprofene,after shock wave lithotripsy of ureteral stones

Extracorporeal shock wave lithotripsy (ESWL) is currently considered one of the main treatments for ureteral stones. Some studies have reported the effectiveness of pharmacologic therapies (calcium antagonists or alpha-blockers) in facilitating ureteral stone expulsion after ESWL. We prospectively evaluated the efficacy, after ESWL, of nifedipine on upper-middle ureteral stones, and tamsulosin on lower ureteral stones, both associated to ketoprofene as anti-edema agent. From January 2003 to March 2005 we prospectively evaluated 113 patients affected by radiopaque or radiolucent ureteral stones. Average stone size was 10.16 ± 2.00 mm (range 6–14 mm). Thirty-seven stones were located in the upper ureter, 27 in the middle ureter, and 49 in the lower ureter. All patients received a single session of ESWL (mean number of shock waves: 3,500) by means of a Dornier Lithotripter S (mean energy power for each treatment: 84%). Both ultrasound and X-ray were used for stone scanning. After treatment, 63 of 113 patients were submitted to medical therapy to aid stone expulsion: nifedipine 30 mg/day for 14 days administered to 35 patients with upper-middle ureteral stones (group A1) and tamsulosin 0.4 mg/day for 14 days administered to 28 patients with stones located in the distal ureter (group A2). The remaining 50 patients were used as a control group (29 upper–middle ureteral stones—B1—and 21 lower ureteral stones—B2—), receiving only pain-relieving therapy. No significant difference in stone size between the groups defined was observed. Stone clearance was assessed 1 and 2 months after ESWL by means of KUB, ultrasound scan and/or excretory urography. A stone-free condition was defined as complete stone clearance or the presence of residual fragments smaller than 3 mm in diameter. The stone-free rates in the expulsive medical therapy group were 85.7 and 82.1% for the nifedipine (A1) and tamsulosin (A2) groups respectively; stone-free rates in the control groups were 51.7 and 57.1% (B1 and B2, respectively). Five patients (14.3%) in group A1, 5 (17.8%) in group A2, 14 (48.3%) in group B1 and 9 (42.8%) in group B2 were not stone-free after a single ESWL session and required ESWL re-treatment or an endoscopic treatment. Medical therapy following ESWL to facilitate ureteral stone expulsion results in increased 1- and 2-month stone-free rates and in a lower percentage of those needing re-treatment. The efficacy of nifedipine for the upper-mid ureteral tract associated with ketoprofene makes expulsive medical therapy suitable for improving overall outcomes of ESWL treatment for ureteral stones.     

Utility of ureteral stent for stone street after extracorporeal shock wave lithotripsy

We reviewed the records of the 530 patients with urinary stones (renal stones: 243; ureter stones 287) who received extracorporeal shock wave lithotripsy (ESWL) (MFL5000; Dornier), from January 1995 to July 2002, retrospectively and determined whether the ureteral stent affected the incidence rate of stone street (SS). We also assessed the effect of ureteral stent on the subsequent management for SS. Forty patients (7.5%) developed SS. Twenty patients were inserted a ureteral stent prior to ESWL (stent group), and 20 patients were performed ESWL without a ureteral stent (in situ group). In the stent group, the most common (80.0%) location for SS was in the upper third ureter, while in the in situ group, SS mostly developed in the distal third ureter (60.0%). The incidence of SS did not differ significantly between the two groups when the size of renal and ureter stones was below 30 and 20 mm, respectively. When the renal stones were larger than above 30 mm, the incidence of SS in the stent group was significantly higher than that in the in situ group. SS disappeared spontaneously with stone passage in 10 of the patients in in situ group, but in only 1 patient in the stent group. In the stent group, 15 patients were treated for SS by removal of ureteral stent regardless of stone diameter. We conclude that ESWL should be performed without a ureteral stent when the stone diameter is below 20 mm. When the ureteral stent is thought to interfere with the delivery of stone fragments, the decision to remove it should be made as soon as possible.     

输尿管软镜钬激光碎石术治疗不同大小肾结石临床疗效的比较分析

目的比较输尿管软镜钬激光碎石术治疗不同大小肾结石的临床疗效。方法回顾性分析2016年6月至2018年3月在我科接受输尿管软镜钬激光碎石术治疗肾结石的121例患者的临床资料,按结石大小分为A组(结石长径≤20 mm)94例、B组(20 mm<结石长径≤30 mm)27例,比较其手术时间、术后住院天数、术后体外冲击波碎石(ESWL)率、并发症及清石率等,评价其临床疗效。结果121例患者均顺利完成手术,A、B两组在手术时间[(46±13)min vs(68±20)min]、术后住院天数[(4.4±1.3)d vs(5.6±1.7)d]及术后选择ESWL率[10.64%(10/94)vs 25.93%(7/27)]等方面差异有统计学意义(P<0.05);在术后总并发症(包括术后腰痛、发热、尿脓毒血症等)发生率[12.77%(12/94)vs 18.52%(5/27)]、总清石率[89.36%(84/94)vs 81.48%(22/27)]等方面差异无统计学意义(P>0.05)。结论应用输尿管软镜钬激光碎石术治疗长径20~30 mm的上尿路结石,在积极防治并发症、术后辅以ESWL等综合治疗下,能取得与结石长径≤20 mm相似的碎石效果。     

Stone disease in kidney transplantation

The aim of this study was to evaluate etiologic, diagnostic, and management aspects of stone disease in renal transplant recipients and donors. Calculi from five patients were analyzed. The immunosuppressive regimen included tacrolimus or cyclosporine, mycophenolate mofetil, and corticosteroids in all cases. The etiology of the stone disease was cadaveric donor-gifted in one patient and de novo stone formation after transplantation in two patients. Additionally, stone disease was found and treated in living related donors in two patients. The mean follow-up was 32.4 +/- 19.7 months. In the living related donors, stones were initially treated by ESWL. Pyelotomy at the back table during the transplantation was required in one of them. The patient with cadaver-gifted stone was also treated by ESWL. In patients with de novo stone formation after transplantation, the stones were related to urinary infections and foreign body double-j (JJ) stent. A small stone in one of these patients (de novo formation) passed spontaneously after removal of the foreign body. Endoscopical lithotripsy was performed in the other patient. Stones are more frequently transplanted with allografts than expected; therefore, preoperative imaging of the donor is important. ESWL is recommended for medium-sized calculi in transplant kidneys. JJ stent insertion before ESWL might be needed in stones larger than 10 mm.     

Is the pediatric ureter as efficient as the adult ureter in transporting fragments following extracorporeal shock wave lithotripsy for renal calculi larger than 10 mm.?

PURPOSE: We determined whether the thin ureter of the young child transports stone fragments after extracorporeal shockwave lithotripsy (ESWL) as efficiently as the adult ureter does. This determination was done by comparing the outcome after lithotripsy of renal stones greater than 10 mm. between young children and adults. MATERIALS AND METHODS: Our study group consisted of 38 children 6 months to 6 years old (median 3 years) with renal stones greater than 10 mm. in diameter. This group was further divided into 3 subgroups according to the longest stone diameter on plain abdominal film. There were 21 children with a renal stone diameter of 10 to 15 mm. (subgroup 1), 8, 16 to 20 mm. (subgroup 2) and 9 greater than 20 mm. (subgroup 3). The control group consisted of 38 adults older than 20 years randomly selected from the local ESWL registry. Each adult was matched with a child regarding stone diameter and localization. The control group was similarly divided into subgroups 1a, 2a and 3a. ESWL was performed with the unmodified Dornier HM-3 lithotriptor (Dornier Medical Systems, Inc., Marietta, Georgia). The stone-free rate, complication rate, and need for tubes, including stent or nephrostomy, and greater than 1 ESWL session were compared. RESULTS: The stone-free rate was 95% in the study and 78.9% in the control group (p = 0.086). Stone-free rates were 95%, 100% and 89% in subgroups 1, 2 and 3, and 95%, 65% and 56% in subgroups 1a, 2a and 3a, respectively. There were 10 children and 4 adults who underwent greater than 1 ESWL session (p = 0.14). Then there were 10 children and 6 adults who required a tube before ESWL (p = 0.04), and almost all of them were included in subgroups 3 and 3a. Early complications were rare in both the study and control groups. Late complications had included 2 cases of Steinstrasse in the control and none in the study group. CONCLUSIONS: The stone-free rate after ESWL for large renal stones is higher in young children compared to adults with matching stone size. Renal stones greater than 20 mm. often require more than 1 ESWL session. The pediatric ureter is at least as efficient as the adult for transporting stone fragments after ESWL.     

Immediate in situ ESWL as monotherapy in acute obstructive urolithiasis: useful or not?

Thirty-two patients with acute obstructive urolithiasis were treated without intervention (stent, nephrostomy tube) within 72 hours after onset of symptoms by extracorporeal shock wave lithotripsy (ESWL). Relief of obstruction, proven sonographically, was obtained within 48 hours in 78.6% of the patients and 90.6% were stone-free 6 weeks after treatment. Best results were obtained for proximal ureteral stones while the influence of stone volume did not appear to be significant. Whereas our stone-free results for treatment of calculi smaller than 5 mm (92.3%) can be criticized because without treatment these stones may pass spontaneously, a high success rate for larger stones (89.4%) was also noted. These results for in situ ESWL compare favorably to those of ESWL with stent bypass and suggest that ESWL monotherapy should be considered as a noninvasive first line therapy when treating acute obstructive urolithiasis.     

Improvement of stone comminution by slow delivery rate of shock waves in extracorporeal lithotripsy

AIM: The aim of this study was to investigate the effect of delivery rate of shockwaves (SW) on stone comminution and treatment outcomes in patients with renal and ureteral stones. METHODS: Patients with radio-opaque stones in the upper urinary tract that were treated by extracorporeal shock wave lithotripsy (ESWL) were divided into two groups according to delivery rate (120 or 60 SW/min). The effective fragmentation after one ESWL session and treatment success at 3 months after ESWL was compared between the two groups. RESULTS: Of 134 patients (84 men and 50 women), 68 patients were treated at a fast rate and 66 were treated at a slow rate. Thirty and 38 patients in the fast rate group and 28 and 38 in the slow rate group had renal and ureteral stones, respectively. After one ESWL session, effective fragmentation was noted more often in the slow group (65.2%) than the fast group (47.1%) (P = 0.035), particularly for smaller stones (stone area <100 mm(2)) (P = 0.005) and renal stones (p = 0.005). However, there was no significant difference in treatment success at 3 months after ESWL between the two groups. In univariate logistic regression analysis, slow SW rate and smaller stones were significant factors for effective fragmentation after one ESWL session. In multivariate analysis, slow SW rate and smaller stones were also independent factors. CONCLUSIONS: Slow SW rate contributed to better stone comminution than fast rate, particularly for small stones and renal stones. ESWL treatment at a slow SW rate is recommended to obtain efficient stone fragmentation.     

A study on the passage of the upper urinary tract stones after in situ ESWL]

Two hundred patients with upper urinary tract stones underwent in situ ESWL with Lithostar during the recent 20 months at Kanagawa Prefectural Atsugi Hospital. Actual residual stone rates were calculated based on the period from the initiation of the treatment to the stone free status, and discussed according to the location and size of the stone treated. Total 200 patients were submitted to 1.67 +/- 0.97 treatment sessions with 6742 +/- 5545 shock waves. After 3 months, 148 patients (78%) showed stone free status, and 32 patients (16%) had residual stones less than 4 mm. The actual residual stone rates were 90.5%, 66.5%, 39.1%, 26.9% and 17.9% after 1, 3, 6, 12 and 20 weeks, respectively. The residual stone rate were lower in the lower ureter, uretero-pelvic junction, upper ureter, renal parenchyma or diverticulum and renal pelvis or calyx in order. As for the size, the larger the stones the higher the residual stone rates; the therapeutic results were significantly worse in patient group of stones larger than 21 mm compared to the patient group of smaller stones (p less than 1%). The destructed stones were passed gradually up to 6th week after in situ ESWL, however, after that fragments seldom passed out. Therefore, it was concluded that decision on the additional or combination therapeutic intervention, if necessary, should be made after 6 weeks. Combination therapy with endoscopic surgery and/or others was seemingly needed for the patients with stones of more than 21 mm in size and of renal pelvis and renal calyx to improve the rates of stone free.