The effect of intracalyceal distribution on the clearance of renal stones of > or = 20 mm in children after extracorporeal lithotripsy

OBJECTIVES: To determine the effect of the intracalyceal distribution of renal stones on clearance rates after treating paediatric nephrolithiasis with extracorporeal shock wave lithotripsy (ESWL). PATIENTS AND METHODS: We assessed a retrospective case series of children (aged < or = 14 years) undergoing lithotripsy on an MPL 9000 (Dornier GmbH, Germany) echo-guided lithotripter. Patients were identified using an international coding and indexing system and ESWL registry. In all, 125 children were treated during 1990-2003, but 21 had stones of > or = 20 mm. Stone clearance was assessed at 1 and 3 months, the stone-free state being defined as no radiological evidence of stone or fragments of < or = 3 mm. Failed treatments were analysed to identify any correlation with stone site. RESULTS: The overall stone-free rate was 81%; in four children the treatment failed (all girls) and subsequently they required ancillary procedures. Nineteen patients (90%) received up to three sessions of ESWL; two required four or more sessions. Of the four children in whom treatment failed, two had JJ stents; the stones were in the lower pole calyx in two, and the renal pelvis and lower pole calyx in two. The mean stone size in those where treatment failed was 25 mm, vs 21 mm in the stone-free group. The complication rate was 19%, but only one child required admission to hospital. CONCLUSIONS: ESWL is very effective for renal stones in children, with minimal morbidity. Lower pole and partial staghorn stones with a major component in the lower pole calyx should preferably be treated by a percutaneous approach.     

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.     

Retrograde intrarenal stone surgery for extracorporeal shock-wave lithotripsy-resistant kidney stones

OBJECTIVE: The newer flexible ureteroscopes, 150-200-microm holmium YAG laser fibres and superflexible Dormia baskets have made it possible to reach and treat stones in all parts of the kidney. The object of this evaluation was to study the outcome of retrograde intrarenal stone surgery (RIRS) for extracorporeal shock-wave lithotripsy (ESWL)-resistant kidney stones. MATERIAL AND METHODS: A total of 38 consecutive patients (18 males, 20 females) participated in the study. All patients had undergone ESWL prior to RIRS without success. In all cases the stones could be reached with the endoscope. Calculi ranged in size from 3 to 20 mm (mean 9 mm). In 32 cases the stones were fragmented using a holmium YAG laser and in six the stones could be extracted using zero-tip Dormia baskets without fragmentation. Sixteen patients had lower calyceal calculi and eight had an abnormal anatomy of the upper urinary tract. Intravenous pyelography was performed 6-8 weeks after the treatment. RESULTS: In all cases the stones could be reached and fragmented to some extent. After a single RIRS procedure, 22/38 patients (58%) were completely stone-free at follow-up, and four (11%) had residual fragments < or = 4 mm in size that were expected to pass spontaneously. Of the remaining 12 patients, who initially had larger stones (mean 11.3 mm), the residual fragments ranged in size from 5 to 15 mm. Three patients underwent an additional RIRS procedure, after which they were all completely stone-free, resulting in an overall success rate of 76%. There were no major complications. CONCLUSIONS: RIRS is a safe procedure with a high success rate and a low complication rate for ESWL-resistant renal stones. Patients with larger stones (> 10 mm), those with stones in the lower pole and those with an abnormal renal anatomy may require more than one procedure.     

Is lower pole caliceal anatomy predictive of extracorporeal shock wave lithotripsy success for primary lower pole kidney stones?

PURPOSE: The management of lower pole kidney stones is controversial. We examined whether lower pole caliceal anatomy could predict the success of extracorporeal shock wave lithotripsy of primary lower pole kidney stones 20 mm. or less. MATERIALS AND METHODS: From December 1997 to June 2001, 246 adults with a single, 20 mm. or less radiopaque lower pole renal stone were treated with the Doli 50 lithotriptor (Dornier Medical Systems, Marietta, Georgia) while under general anesthesia. Of the 246 patients 190 (77%) had excretory urography available for review. Lower pole infundibular length and width, lower pole infundibulopelvic angle and caliceal-pelvic height were measurable on 161 (85%), 129 (68%), 128 (67%) and 163 (86%) excretory urograms, respectively. Extracorporeal shock wave lithotripsy was considered a failure if residual stone fragments remained after 1 month, or an auxiliary procedure or re-treatment was required.RESULTS The overall stone-free rate was 78% (32 of 41) for stones 5 mm. or less, 73% (98 of 135) for stones 6 to 10 mm., 43% (22 of 51) for stones 11 to 15 mm. and 30% (7 of 19) for stones 16 to 20 mm. in maximum linear dimension. The stone-free rates grouped according to stone surface area were 76% (48 of 63 stones) for stone surface area 25 mm.2 or less, 69% (97 of 141) for 26 to 100 mm.2 and 33% (14 of 42) for 101 to 400 mm.2. Caliceal anatomy was not predictive of success even with stones grouped as 10 or less or 11 to 20 mm. Grouping patients with favorable (lower pole infundibulopelvic angle 70 degrees or greater, lower pole infundibular length 30 mm. or less and lower pole infundibular width greater than 5 mm.) versus unfavorable (70 degrees or less, greater than 30 mm. and 5 mm. or less, respectively) anatomy was also not predictive of success. CONCLUSIONS: On the Doli 50 machine stone size rather than caliceal anatomy is predictive of treatment outcome. Initial treatment failures with this machine should be managed by alternative endoscopic procedures if necessary rather than by repeat shock wave lithotripsy.     

LOWER POLE I: A PROSPECTIVE RANDOMIZED TRIAL OF EXTRACORPOREAL SHOCK WAVE LITHOTRIPSY AND PERCUTANEOUS NEPHROSTOLITHOTOMY FOR LOWER POLE NEPHROLITHIASIS—INITIAL RESULTS

PURPOSE: The efficacy of shock wave lithotripsy and percutaneous stone removal for the treatment of symptomatic lower pole renal calculi was determined. MATERIALS AND METHODS: A prospective randomized, multicenter clinical trial was performed comparing shock wave lithotripsy and percutaneous stone removal for symptomatic lower pole only renal calculi 30 mm. or less. RESULTS: Of 128 patients enrolled in the study 60 with a mean stone size of 14.43 mm. were randomized to percutaneous stone removal (58 treated, 2 awaiting treatment) and 68 with a mean stone size of 14.03 mm. were randomized to shock wave lithotripsy (64 treated, 4 awaiting treatment). Followup at 3 months was available for 88% of treated patients. The 3-month postoperative stone-free rates overall were 95% for percutaneous removal versus 37% lithotripsy (p <0.001). Shock wave lithotripsy results varied inversely with stone burden while percutaneous stone-free rates were independent of stone burden. Stone clearance from the lower pole following shock wave lithotripsy was particularly problematic for calculi greater than 10 mm. in diameter with only 7 of 33 (21%) patients becoming stone-free. Re-treatment was necessary in 10 (16%) lithotripsy and 5 (9%) percutaneous cases. There were 9 treatment failures in the lithotripsy group and none in the percutaneous group. Ancillary treatment was necessary in 13% of lithotripsy and 2% percutaneous cases. Morbidity was low overall and did not differ significantly between the groups (percutaneous stone removal 22%, shock wave lithotripsy 11%, p =0.087). In the shock wave lithotripsy group there was no difference in lower pole anatomical measurements between kidneys in which complete stone clearance did or did not occur. CONCLUSIONS: Stone clearance from the lower pole following shock wave lithotripsy is poor, especially for stones greater than 10 mm. in diameter. Calculi greater than 10 mm. in diameter are better managed initially with percutaneous removal due to its high degree of efficacy and acceptably low morbidity.     

压电,液电和电磁式体外冲击波治疗输尿管下段结石效果的比较

目的 采用压电、液电和电磁式第二体外冲击波碎石机治疗输尿管下段结石,观察和比较其疗效。方法 １９８７年以来共收治输尿管下段结石患者６０３例,按机型分为３组;ＥＤＡＰ－ＬＴ０１压电组１７９例,ＪＤＰＮＩＶ型液电阻２９４例,Ｄｏｒｎｉｅｒ ＣｏｍｐａｃｔＳ型电磁组１３０例,每组按结石大小又分为〈１０ｍｍ,１０￣１５ｍｍ和〉１５ｍｍ３个亚组。结果 电磁组的一次性无石率高于其它两组,压电组的效率商低于电组     

The impact of radiological anatomy in clearance of lower caliceal stones after shock wave lithotripsy

The goal of this study was to determine the factors affecting stone clearance after extracorporeal shock wave lithotripsy (ESWL) for lower caliceal stones. Lower pole stone clearance was investigated in 128 (80 males, 48 females) patients treated with ESWL during 1998–2003 in our clinic. Renal anatomy was determined on standard intravenous urogram. The lower infundibulopelvic angle (LIPA) was measured as the angle between the vertical pelvis axis and the vertical axis of lower infundibulum (Sampaio’s method). The mean age of the patients was 42.8 ± 12.4 (19–77) years. The mean stone diameter and burden were found to be 1.28 ± 0.58 (0.5–3.5) cm and 1.2 ± 1 (0–7) cm² respectively. The stone-free rate was 62.5% and ESWL was unsuccessful in 16 (12.5%) patients. Thirty-two (25%) patients had residual fragments ≤4 mm retained in lower calices after lithotripsy. The stone clearance was found to be unrelated to stone burden and diameter (P = 0.17 and P = 0.14, respectively). However, there was a significant difference between mean lower pole infundibulum length (P = 0.001), infundibulum width (P = 0.001) and LIPA (P = 0.0001) between stone-free patients and patients with residual fragments. Multivariate logistic regression analysis accepting stone-free as the favourable result also confirmed that LIPA, lower pole infundibulum length and width were factors that significantly affected the outcome. Lower pole anatomy has a significant influence on clearance of fragments after ESWL.     

Prediction of success rate after extracorporeal shock-wave lithotripsy of renal stones--a multivariate analysis model

OBJECTIVES: To define prognostic factors that affect the success rate after extracorporeal shock-wave lithotripsy (ESWL) of renal calculi and to estimate the probability of stone-free status using a regression analysis model. MATERIAL AND METHODS: Between February 1992 and February 2002, 2954 patients with single or multiple radiopaque renal stones (<30 mm) underwent ESWL monotherapy. The results of treatment were evaluated after 3 months of follow-up. Treatment success was defined as complete clearance of the stones with no residual fragments. The stone-free rate was correlated with stone features and patient characteristics using the chi2 test. Factors found to be significant using the chi2 test were further analyzed using multivariate regression analysis. RESULTS: At 3-month follow-up, the overall stone-free rate using ESWL monotherapy was 86.7%. Failure to disintegrate the stones was observed in 7.3% of cases (n = 216) and failure to clear the fragmented stones occurred in 6% (n = 177). Repeat ESWL was needed in 53% of cases. Static steinstrasse occurred in 4.9% of cases (n = 146) and post-ESWL auxiliary procedures were required in 4% (n = 118). Using the chi2 test, patient age (p < 0.001), stone size (p < 0.001), location (p < 0.001), number (p < 0.001) and nature (p = 0.003), radiological renal picture (p < 0.001) and congenital renal anomalies (p < 0.001) had a significant impact on the stone-free rate. Multivariate analysis excluded stone nature from the logistic regression model while other factors maintained their statistically significant effect on success rate, indicating that they were independent predictors. A regression analysis model was designed to estimate the probability of stone-free status after ESWL. The sensitivity of the model was 83%, the specificity 91% and the overall accuracy 87%. CONCLUSION: Patient age, stone size, location and number, radiological renal features and congenital renal anomalies are prognostic factors determining stone clearance after ESWL of renal calculi. Our regression model can predict the probability of the success of ESWL with an accuracy of 87%.     

Impact of stone size, location, composition, impaction, and hydronephrosis on the efficacy of holmium:YAG-laser ureterolithotripsy

OBJECTIVES: The impact and outcome of holmium:YAG-laser (Ho:YAG) ureterolithotripsy in treating proximal and distal ureteral stones was investigated. METHODS: A total of 543 patients harbouring proximal (n=194) or distal (n=349) ureteral stones underwent semirigid Ho:YAG ureterolithotripsy. The degree of hydronephrosis; stone size, location, impaction, and composition; and complication and stone-free rates were recorded. RESULTS: Mean stone size for proximal and distal stones was 7.1+/-3.6 mm and 6.2+/-2.5 mm, respectively. The stone-free rate on the first postoperative day was 79.4% for proximal and 96.8% for distal stones (p<0.0001). For proximal stones <10mm and > or =10mm, respectively, the stone-free rate was 80.5% and 74.3% (p=0.4) and for distal stones 97.3% and 94.3% (p=0.2). Stone-free rates for radio-opaque versus radiolucent stones in proximal stones were 79.6% versus 77.9% (p=0.8) and 97.6% versus 96.2% in distal stones (p=0.5). Impaction correlated significantly with stone-free rates (p<0.0001). Stone-free rates for nonimpacted versus impacted proximal stones were 85.8% versus 67.2% (p=0.003) and for distal stones 99.2% versus 91.4% (p<0.003), respectively. The presence or degree of hydronephrosis did not correlate with treatment success (p=0.4, p=0.8). The presence of intraoperative complications correlated significantly with proximal compared to distal ureteral stone location (p=0.004). Auxiliary measures in proximal versus distal stones were performed in 20.6% versus 2.9% (p<0.0001). CONCLUSIONS: In this series, stone-free rates in Ho:YAG ureterolithotripsy were significantly higher in distal and nonimpacted stones but were independent of stone size and composition and the degree of hydronephrosis. Ureterolithotripsy in proximal stones was associated with higher intraoperative complication and retreatment rates compared to distal stones.     

Extracorporeal shock wave lithotripsy with the Storz Modulith SL20: the first 500 patients.

Our initial experience of extracorporeal shock wave lithotripsy (ESWL) with the Storz Modulith SL20 is reported. A total of 500 patients with 551 renal and 120 ureteric stones, mean diameter 11.9 mm, underwent 746 treatments; 68.2% of patients required a single treatment. The mean treatment rate for renal calculi was 1.4 and for ureteric calculi it was 1.5, rising to 4.2 for staghorns; 62.2% of treatments were performed on an out-patient basis. Analgesia (intravenous fentanyl) was required in 60.9% of treatments for renal calculi but in only 38.2% of those for ureteric calculi. The overall stone-free rate at 3 months was 77.6%, with a further 14.7% of patients having fragments less than 3 mm in diameter that required no further treatment. The stone-free rate was dependent on the site of the stone, with the majority of residual fragments lying in a lower pole calix. There were few complications. The Modulith is an efficient and safe lithotripter capable of treating stones in the kidney and throughout the ureter.     

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.     

Comparative study of long-term stone recurrence after extracorporeal shock wave lithotripsy and open stone surgery for kidney stones

Background: Extracorporeal shock wave lithotripsy (ESWL) has become the treatment of choice for most calculi of upper urinary tract and the need for open stone surgery (OSS) have considerably reduced. However, stone recurrence is often encountered as a long-term problem requiring re-treatment.
Methods: In the present retrospective study, the recurrence rates of ESWL and OSS were compared in the treatment of kidney calculi. During the 1 year period of the present study, 43 patients were treated by OSS and 400 underwent ESWL (the Dornier MPL 9000 lithotriptor). The recurrence of stone was defined as reappearance of the stone on plain abdominal radiography during the follow-up period.
Results: Complete removal of all stone fragments was achieved in 51.2% of patients ( n = 22) treated with OSS. In the ESWL group, the stone free rate was 56.7% ( n = 237). The recurrence rate was 31.8% within a mean of 40 months (range 32–48 months) in the OSS group, whereas this figure was 13.9%, with a mean period of 46 months (range 42–48 months) in the ESWL group ( P < 0.05). The mean periods of recurrence in ESWL and OSS groups were 20 (range 6–42 months) and 11 months (range 8–44 months), respectively ( P < 0.05). However, the mean stone burdens of both groups were different (2.9 ± 0.8 vs 1.4 ± 1.1 cm). For comparable stone burdens, the recurrence rate was similar. In the ESWL group, stones in the lower calyx, multiple stones and larger stones showed a higher recurrence rate. The recurrence after OSS was also influenced by stone burden.
Conclusions: The results of the present study demonstrate that stone burden may be the primary risk factor for stone recurrence after ESWL and OSS.     

Prognostic factors for extracorporeal shock-wave lithotripsy of ureteric stones--a multivariate analysis study

OBJECTIVE: To define factors that have a significant impact on the stone-free rate after extracorporeal shock-wave lithotripsy (ESWL) of ureteric stones using multivariate analysis. MATERIAL AND METHODS: Between February 1992 and February 2002, a total of 938 patients with ureteric stones were treated with in situ ESWL using the Dornier MFL 5000 lithotripter. The outcome of treatment was evaluated after 3 months and failure was defined as the presence of any residual stones. The stone-free rate was correlated with patient characteristics (age, sex and radiological renal picture) and stone features (site, side, length, width, nature, opacity and the presence of ureteral stents). Factors with a significant impact on the stone-free rate using the chi (2) test were further analyzed using multivariate analysis. RESULTS: Overall, the stone-free rate was 88.7%. Repeat treatment was required in 50.4% of cases. Post-ESWL complications were observed in 32 cases (3.4%), including static steinstrasse in 19 (2%). Auxiliary procedures were needed in 28 cases (3%). Using the chi (2) test, only three factors had a significant impact on the stone-free rate, namely stone site, the transverse diameter of the stone and the presence of a ureteral stent. The stone-free rate was highest for stones located in the lumbar ureter (436/470; 92.8%) and lowest for those located in the pelvic ureter (268/324; 82.7%) (p = 0.0017). Stones with a transverse diameter of < or =1 cm were associated with a stone-free rate of 89.7% (715/797), compared to 83% (114/141) for those with a transverse diameter of >1 cm (p = 0.017). Non-stented patients had a stone-free rate of 89.8% (732/815), compared to 81.3% (100/123) for stented patients (p = 0.006). On multivariate analysis, these three factors maintained their statistical significance. A logistic regression model was designed to estimate the probability of stone-free status after ESWL. CONCLUSION: The site and transverse diameter of the stone and the presence of a ureteral stent are the only significant predictors of success of ESWL therapy for ureteric stones.     

Monotherapy with extracorporeal shock wave lithotripsy for renal and ureteral stones]

We performed extracorporeal shock wave lithotripsy (ESWL) as a monotherapy using the Medstone STS lithotripter on 288 patients with renal and ureteral stones between June, 1989 and June, 1991. We compared our results with previous reports on ESWL as used in combination therapy. Our cases consisted of 121 patients with renal stones and 167 patients with ureteral stones. A total of 437 sessions of lithotripsy were performed on 288 patients, for an average of 1.52 sessions of lithotripsy per patient. The percentage of stones measuring less than 4.0 mm in diameter that were fragmented was 94.3% for renal stones and 87.6% for ureteral stones. The stone-free rates 3 months after ESWL were 60.3% and 90.4%, respectively. Our results of the monotherapy with ESWL did not differ from those reported on ESWL as used in combination therapy, in terms of the rate of stone destruction and stone-free rates. We studied the other reports carefully and determined that ESWL monotherapy could have been performed in most those cases. We concluded that ESWL monotherapy is an excellent therapeutic method in the light of fewer complications and side effects compared with those from combination therapy, and the fact that the rate of recurrence for renal and ureteral stones is high makes ESWL monotherapy very useful because the procedure can be repeated.     

The 'modified prone position': a new approach for treating pre-vesical stones with extracorporeal shock wave lithotripsy

OBJECTIVE: To investigate the utility of a new 'modified-prone' position for treating pre-vesical stones with extracorporeal shock wave lithotripsy (ESWL), usually considered an acceptable and effective treatment for such stones, but for which many different body positions have been used in an attempt to increase its efficacy. PATIENTS AND METHODS: The study included 268 consecutive patients with a solitary pre-vesical stone who underwent ESWL either prone (69) or in the modified-prone position (199) between May 1999 and August 2001. Only those with one stone between the ureteric orifice and 1 cm proximal to the vesico-ureteric junction were included. In each case the stone diameter, days to stone clearance, number of shock waves applied per treatment, and number of sessions required to become stone-free were recorded. If the treatment failed this was also noted. Success rates in the prone and modified-prone groups were compared and analysed to assess which of the variables influenced success with ESWL. RESULTS: After ESWL, 95.5% of the 268 patients were stone-free; the rates in the prone and modified-prone groups were 89.9% and 97.5%, respectively (P = 0.015). The probability of success with ESWL therapy for pre-vesical calculi in modified-prone position was about five times (odds ratio 4.56, 95% confidence interval 1.2-17.7) greater than that expected with when prone. The modified-prone position was an independent factor most significantly influencing success with ESWL in these patients. CONCLUSION: The modified-prone position for ESWL is a new and very effective way to treat patients with pre-vesical stones.     

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.     

Emergency extracorporeal shock wave lithotripsy (ESWL) for obstructing ureteral stones

OBJECTIVE: To evaluate emergency treatment of obstructing ureteral stones by in situ extracorporeal shock wave lithotripsy (ESWL) during acute renal colic. PATIENTS AND METHODS: From January 1994 to February 2000, 200 patients (mean age: 42 years) were treated by ESWL (EDAP LT-02) for obstructing ureteral stones causing acute renal colic refractory to medical treatment or recurring within 24hours of such treatment. Stones were visualised by fluoroscopic imaging and/or ultrasound. Follow-up included radiological and/or ultrasound examinations and lasted three months. RESULTS: Mean stone size was 7mm (3-20mm). At three months, 164/200 (82%) patients were stone-free. This rate ranged from 79% to 83% according to the location of the stone, and from 75% to 86% according to the size of the stone. These differences in rate were not significant. Two or three ESWL sessions were required in 79 patients. ESWL was well tolerated in 90% of patients. The only complication was a case of pyelonephritis requiring the placement of a JJ stent, administration of antibiotics, and distant ureteroscopy. The 36 patients, in whom ESWL failed, underwent ureteroscopy (n=23) or lithotripsy with a Dornier machine (n=13). CONCLUSION: Non-deferred ESWL for acute renal colic secondary to obstructing ureteral stones has a satisfactory success rate and very low morbidity.     

Usefulness of lower ihfundibular length-to-diameter ratio as a predictor of lower pole stone clearance after extracorporeal shock wave lithotripsy; clinical research with two lithotriptors

PURPOSE: Lower pole renal stones are well known to exhibit a poor stone clearance rate following extracorporeal shock wave lithotripsy (ESWL). In the present study, we analyzed several anatomical factors as predictors of lower pole stone clearance that may be used to indicate the usefulness and the universality of ESWL in such patients with two different lithotriptors. PATIENTS AND METHODS: 93 patients with a unilateral single lower pole stone of 2 cm. or less underwent ESWL using Piezolith 2500 or Medstone STS, were included in the study. An IVP was used to determine the lower infundibulopelvic angle, the caliceal pelvic height, the lower infundibular length, the lower infundibular diameter, the lower infundibular length-to-diameter ratio and the number of lower pole minor calyces. Stone-free status was assessed by a plain film with or without renal ultrasound. RESULTS: The stone clearance rate at the Piezolith 2500 group was 53.1% (34 of 64 patients), while was 51.7% (15 of 29 patients) at the Medstone STS group. In all cases, the overall stone clearance rate was 52.7% (49 of 93 patients). Age, laterality of the stone burden within the kidney and stone size were not different between the stone-free and residual stone groups. Multivariate logistic analysis revealed that length-to-diameter ratio was the most independent predictors of successful stone clearance at each group. The patients exhibited length-to-diameter ratio less than 7 achieved high stone clearance rates, greater than 72%. In contrast, the stone clearance rate was less than one third when length-to-diameter ratio was 7 or greater. Besides length-to-diameter ratio was strong prognostic factor in patients with stones 1 cm. or less and 1 to 2 cm at each group. CONCLUSION: From this study, it is apparent that successful ESWL is highly sensitive to the anatomy of the lower pole of the kidney. Especially, the lower infundibular length-to-diameter ratio is potentially useful and a universal predictor regardless of the kind of lithotriptors at least in patients with a lower pole radiopaque stone 2 cm. or less treated with ESWL.     

Management of ureteral stones by extracorporeal shock wave lithotripsy. 3 years of experience

From April 1985 to March 1987 181 patients with ureteral stones were treated by means of extracorporeal shock wave lithotripsy (ESWL). Management for proximal calculi changed from in situ ESWL treatment (group n = 27) or placement of a ureteral catheter below calculi (group II, n = 30) to retrograde stone manipulation into renal pelvis (group IV, n = 52) or ESWL treatment under intraoperative irrigation of saline in cases where repositioning failed (group III, n = 50). The best stone-free rate for upper ureteral stones was obtained in group IV with 96% after 6 weeks, presenting also the shortest hospital stay (4.2 days) and lowest quota of postoperative auxiliary procedures (2%). Stones, not being dislodged into renal pelvis (49%), could be treated successfully in 86% by irrigation with saline during ESWL (group III). The stone-free rate decreased in patients with in situ treatment (group I: 67%) or ureteral catheter placement (group II: 83%). Treatment of these stones increased the need of postoperative ancillary procedures to approximately 30%. For distal ureteral stones ESWL and preoperative Zeiss placement achieved a stone-free rate of 95%.     

Evaluation of a synchronous twin-pulse technique for shock wave lithotripsy: the first prospective clinical study

OBJECTIVE: To present the results of the first clinical study of a synchronous twin-pulse technique for extracorporeal shock-wave lithotripsy (ESWL), which is effective for in vitro stone fragmentation and safe when assessed in vivo on animal tissue. PATIENTS AND METHODS: Fifty patients with urinary stones (35 men and 15 women) were enrolled and treated with the TWINHEADS lithotripter. The entry criteria were: age > or = 18 years, with a radio-opaque single stone in the kidney or upper ureter, a normal laboratory profile (serum creatinine, liver function, blood, bleeding and clotting times, and prothrombin concentration). The exclusion criteria included lower ureteric stones, patients with urinary tract infection, obstructed urinary tract distal to the stones, or congenital abnormalities. All patients received one session and were evaluated by ultrasonography (US), urinary tract plain X-ray, and complete laboratory investigations before and immediately after treatment, and after 2, 14 and 30 days. Patients requiring re-treatment at the 14-day visit received a second session and were re-evaluated after 7 and 14 days. RESULTS: The mean (sd, range) stone size (longest diameter) was 12.3 (2.6, 9-18) mm. Intravenous sedation was used in 30 patients. There was mild haematuria in 25 patients on the day of treatment. During the follow-up there was no evidence of haematoma, gross renal injury, upper urinary tract obstruction or significant changes in the laboratory investigations. After 14 days, 17 patients (34%) were free of stones, with residual stones of < or = 5 mm in 20 (40%); they were free of stones at the 1-month follow-up. Thirteen patients (26%) had residual stones of 6-9 mm, but the stones were half or less of the original size. Patients with residual stones of > 5 mm had another ESWL session and were free of stones within 14 days. Thus all patients were rendered stone-free within 1 month. CONCLUSIONS: Synchronous twin-pulse ESWL is promising, seems safe and effective for treating patients with renal and upper ureteric lithiasis.