Primary in situ extracorporeal shock wave lithotripsy in the management of ureteric calculi: results with a third-generation lithotripter.

OBJECTIVE: To review the results of primary in situ extracorporeal shock wave lithotripsy (ESWL) for the treatment of ureteric stones using a third-generation lithotripter, the Dornier MFL 5000 (Dornier Medizentechnic, Germany). PATIENTS AND METHODS: The study comprised a retrospective review of treatment outcome in 180 patients with 196 stones who were treated with primary in situ ESWL, assessing the success of this approach and establishing reasons for failure. RESULTS: At the 3-month follow-up, 88% of patients were stone-free; 21 patients failed ESWL and were treated by ureteroscopic stone extraction with no complications. Stone-free rates were 90% for upper ureteric, 89% for middle-third and 86% for lower-third calculi. Twenty-one patients required auxiliary procedures in the form of JJ stenting or nephrostomy. Failure of ESWL was associated with stone size (>1.3 cm) but not location or inadequate treatment. CONCLUSION: Where prompt access to ESWL is available, primary in situ ESWL remains an effective form of treatment for all ureteric calculi, although stone-free rates are lower for larger stones.     

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.     

How do increasing stone surface area and stone configuration affect overall outcome of percutaneous nephrolithotomy?

BACKGROUND AND PURPOSE: Studies reporting the outcome of percutaneous nephrolithotomy (PCNL) in relation to stone burden and configuration are limited. We analyzed our stone-free and complication rates of PCNL with regard to stone surface area and configuration. PATIENTS AND METHODS: Data of 234 patients who underwent PCNL were analyzed retrospectively. Patients were stratified into six groups according to stone burden and into four groups in relation to stone configuration. Groups were compared with respect to the number of tracts, success of therapy, complications, requirement for secondary procedures, drop in hematocrit, and blood transfusion requirement. RESULTS: The overall stone-free rate was 78.6% with a complication rate of 34.6%. Stone-free rates decreased with increasing stone size (P = 0.001) and with increasing caliceal component in complex stones (P = 0.01). The total number of complications rose with increasing stone surface area (P = 0.0001); however, stone distribution within the kidney did not affect the complication rate (P = 0.2). The mean operative time rose with increasing stone burden (P < 0.05) and increasing caliceal involvement by complex stones (P < 0.01). The need for multiple tracts also rose with increasing stone burden (P < 0.05). CONCLUSION: There is a decrease in the overall stone-free rate, as well as an increase in the complication rate, the secondary procedure rate, the mean operative time, and the need for multiple tracts, with increasing stone surface area with PCNL. With regard to stone configuration, there is a decrease in the stone-free rate, as well as an increase in the operative time, with increasing caliceal component in complex renal stones.     

Impact of shockwave coupling on efficacy of extracorporeal shockwave lithotripsy

PURPOSE: To evaluate the impact of a slow gated treatment rate on the efficacy of extracorporeal shockwave lithotripsy (SWL). PATIENTS AND METHODS: From August 1990 to July 2002, 40,462 SWL procedures were performed using the slow frequency electrocardiography (ECG)-gated lithotripter (82.5%) and fast frequency ECG-ungated (17.5%) modes for the Medstone STS lithotripter. Treatment characteristics, including the mode of SWL, location and size of the stone, re-treatment status, auxiliary procedures required, perioperative complications, and treatment outcomes, were recorded. The stone-free rate was reported by the treating physician on the basis of the finding of no residual stone fragments on a plain radiographic image. RESULTS: The treatment rate for the slow mode was a mean of 79.6 shocks/min, while the rate for the fast mode was 120/min. The total procedure time was 47.0 minutes for the slow mode and 40.6 minutes for the fast. The overall stone-free rate was higher for slow (66.9%) than fast (63.6%) procedures (P < 0.001). The stone-free rate for 1- to 10-mm stones was higher for the slow procedures (75.7%) than the fast procedures (70.7%; P < 0.001). Upper-ureteral stones responded better to slow treatment in terms of stone-free rate (79.5% v 72.6%; P < 0.001), re-treatment rate (6.5% v 8.0%, P = 0.05), auxiliary-procedure rate (6.1% v 8.9%; P = 0.01), and efficiency quotient (71 and 62). There was no significant difference in complication rates overall between slow and fast treatment. CONCLUSIONS: With a minimal increase in procedure time, greater efficacy can be obtained for the treatment of radiopaque stones with a slower shock-delivery rate. In particular, upper-ureteral calculi and calculi <10 mm benefit from a slower treatment rate.     

Anesthesia for extracorporeal shockwave lithotripsy: Teikyo University Hospital experience using the third generation lithotripter

A single-board certified urologist with training and experience in anesthesiology was assigned to treat 502 patients (185 with renal stones, 317 with ureteral stones) using the Dornier Compact Delta lithotripter under general or epidural anesthesia. Data were obtained regarding stone location, stone size, shockwave use, stone-free rate, and complications. In all, 502 stones were treated with the Dornier Compact Delta lithotripter. Among renal stones, 73% were in the renal pelvis. Among ureteral stones, 60% were in the upper, 10% in the middle, and 30% in the lower ureter. Diameters of 61.8% of stones were less than 1 cm. The mean number of shocks was 3,471 at a mean power setting of 5. The stone-free rate for renal stones was 71.5%, while for ureteral stones this reached 99%. The efficiency quotient was calculated as 0.65. One patient with a renal stone developed perinephric hematoma requiring 3 units of transfusion. With a success rate higher than that reported for other lithotripters, the Dornier Compact Delta lithotripter represents a feasible treatment for urolithiasis. We stress that even in the third generation machines the lithotripsy under anesthesia can improve the treatment efficacy.     

Operator experience and adequate anesthesia improve treatment outcome with third-generation lithotripters.

PURPOSE: To characterize the effect of operator experience and type of anesthesia on treatment outcome when switching from the Dornier HM3 to the third-generation Dornier U/50 lithotripter. PATIENTS AND METHODS: A population of 370 consecutive patients treated by 15 urologists was divided into two groups. Group I (N = 225) included patients treated during the initial 3 months with our new lithotripter. Group II (N = 145) included patients treated during the last 3 months. Changes were made during the intervening 6 months in focusing technique, anesthesia type, coupling technique, and shockwave delivery. Information was collected regarding success of stone treatment (defined as complete clearance of stone or fragments < 3 mm at 1 month). RESULTS: There were no differences between the two groups with regard to age, sex, fluoroscopic time or maximal shockwave intensity used. Group I had a slightly higher percentage of upper ureteral stones (20% v 13%); however, the difference was not significant. Upper ureteral stones in Group II were on average significantly larger (9.4 mm v 7.3 mm; P = 0.003). Intravenous sedation was used frequently in Group I (111 patients; 49%) and not at all in Group II. General anesthesia was used more frequently in Group II than in group I (34% v 24%; P < 0.02). Spinal anesthesia also was utilized more frequently in Group II patients (66% v 28%; P < 0.0001). Overall, general or regional anesthesia was received by 100% of the patients in Group II but only 52% of the patients in group I. The success rate of stone treatment was much better for Group II than for Group I (78% v 51%; P < 0.0001). CONCLUSION: The transition from a Dornier HM3 lithotripter to a third-generation lithotripter can be difficult, but if adequate anesthesia is given to minimize patient movement and balloon pressures are optimized, stone targeting can be accurate and similar stone clearance rates can be obtained.     

Urologic experience with the Dornier multipurpose lithotripter MPL 9000

From March, 1988 until October, 1989, 502 patients with 603 stones were treated with the Dornier multipurpose lithotripter MPL 9000. Sixty-six percent of the stones were situated in the calix, 29.6% in the renal pelvis, 3% in the upper, and 1% in the distal ureter; 18.4% of the stones were radiolucent. Multiple MPL treatments were performed in 8.6%. In 6.1% fragments post-ESWL treatment were larger than 5 mm. In 58.6% of the treatments were performed without using analgesia or anesthesia. Intravenous anesthesia was used in 22.3%, analgesia and sedation in 16.9%, general anesthesia in 1.4%, and epidural anesthesia in 0.8%. After 3 months follow-up 73.1% were stone-free. Residual fragments were found in the upper calix in 1.1%, in the middle calix in 5.2%, in the lower calix in 13.4%, in the renal pelvis in 5.9%, and in the ureter in 1%. The MPL 9000 has been proven to be as effective for the treatment of renal stones, while difficulties in localizing ureteral stones were noted. The major number of treatments were performed without any analgesia or anesthesia. No major complications were encountered.     

The Dornier Compact Delta lithotripter: the first 500 renal calculi

BACKGROUND AND PURPOSE: Extracorporeal Shockwave Lithotripsy (SWL) is now the best noninvasive treatment for renal calculi, rendering many patients stone free. This prospective study was performed to evaluate the short-term results of patients undergoing SWL with the Dornier Compact Delta lithotripter for all renal calculi. PATIENTS AND METHODS: Between April 1999 and May 2000, there were 500 renal calculi treated in 166 female and 334 male patients with a mean age of 53 +/- 15 years. All patients who completed treatment were entered in the study and assessed at 1 and 3 months with a plain film of the kidneys, ureters, and bladder. Stone-free rate and final outcome have been evaluated. Final outcome is defined as stone free or residual fragments 4 mm or less. Analysis has been made according to stone size, location, number of treatments per stone, and number of shocks per stone. The analgesia requirements during each treatment and complications have also been analyzed. RESULTS: The overall stone-free rate for stones <10 mm was 62% at 1 month and 76% at 3 months. For stones 10 to 20 mm, these rates were 53% and 66%, while the rates for stones >20 mm were 41% and 47%, respectively. The final outcome for stones <10 mm was 90% at 1 month and 93% at 3 months, for stones 10 to 20 mm 73% and 84%, and for stones >20 mm 57% and 67%, respectively. The effectiveness quotient for calculi <10 mm was 60%. For calculi 10 to 20 mm, it was 51%, and for those >20 mm, it was 31%. Oral analgesia was given routinely; however, additional intravenous analgesia was necessary in 22% of treatments. No serious complications have been seen. CONCLUSIONS: These results show that with proper patient selection, good results at 1 and 3 months can be achieved with minimal anesthesia during treatment and low retreatment rates. We do not recommend SWL as primary therapy for stones >20 mm.     

Comparative results of shockwave lithotripsy for renal calculi in upper, middle, and lower calices

BACKGROUND AND PURPOSE: To assess the results of shockwave lithotripsy (SWL) for renal calculi in upper, middle, and lower calices according to the stone burden. PATIENT AND METHODS: A series of 52 female and 66 male patients with a mean age of 47.8 years and isolated single caliceal stones who underwent SWL monotherapy were enrolled. Stone burden, stone location, number of sessions/shockwaves, and auxiliary procedures were noted for each patient. Stones were located in the upper, middle, and lower calices of 35, 43, and 40, patients respectively, with mean stone burdens of 81.4 mm2, 75.2 mm2, and 96.3 mm2, respectively. Patients were evaluated with intravenous urography, plain film, or ultrasonography. Success was determined 3 months after the last session. Re-treatment rates were calculated. The effect of anatomic factors on the success of treatment for lower-caliceal stones also was determined. RESULTS: The mean stone burden, median number of treatment sessions, and mean number of shockwaves were 84.2 mm2, 2, and 4344, respectively. The auxiliary procedure rate was 16.1%, and the re-treatment rate was 71.2%. Failure was noted in 26 patients (22%). The stone-free rates for stones in the upper, middle, and lower calices were 82.8%, 83.4%, and 67.5%, respectively (P = 0.14). The stone-free rates for stones <100 mm2 and 100 to 200 mm2 were 91.2% and 65.5%, respectively (P = 0.001). The efficiency quotient was 49.8, 44.8, and 32.5 for upper-, middle-, and lower-caliceal stones, respectively. Infundibular length (P = 0.006) and infundibular width (P + 0.036) were significant in determining the stone-free rate after treatment of lower-caliceal stones. CONCLUSIONS: We recommend SWL as the first choice for treatment of stones <200 mm2 in the upper and middle calices. Extracorporeal lithotripsy is one of the options for lower-caliceal stones <200 mm2 but has high re-treatment and auxiliary-procedure rates in these cases.     

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.     

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.     

急诊输尿管镜钬激光碎石与体外冲击波碎石治疗输尿管结石并急性肾绞痛的疗效比较

目的比较急诊输尿管镜钬激光碎石（URL）与急诊体外冲击波碎石（ESWL）两种方法治疗输尿管结石引起的急性肾绞痛的疗效。方法2006年1月至2008年9月，采用Storz8／9F硬质输尿管镜、钬激光碎石机和DornierCompactS型低能量电磁式碎石机分别急诊治疗输尿管结石并肾绞痛175例和110例。所有病例均先行药物治疗症状无缓解后在急诊初诊12h之内接受急诊URL或急诊ESWL。结果对于输尿管上段结石，术后疼痛缓解率URL组虽优于ESWL组（93．94％和66．67％，P〈O．05），但碎石成功率（84．85％和83．33％，P〉0．05）及二周结石排净率（81．81％和77．78％，P〉0．05）均无显著差异。而对于输尿管中下段结石，术后疼痛缓解率（98．59％和92．39％）、碎石成功率（98．59％和91．30％）以及二周结石排净率（97．18％和94．78％）URL组均优于ESWL组fP〈0．05）。最大径10mm以内的结石URL组碎石成功率优于ESWL组（96．38和88．10％，P〈0．05）。最大径10mm以上的结石，术岳疼痛缓解率及2周排净率URL组均优于ESWL组（97．30％和69．23％，91．89％和61．23％，P〈0．05）。5RL及ESWL组并发症率分别为3．46％和2．73％（P〉0．05）。结论急诊URL和急诊ESWL均是输尿营结石并急性肾绞痛的安全、有效的治疗方法，对于输尿管上段结石或最大径不超过10mm的结石二首效果相当，而对于输尿管中下段结石或直径大于10rllm的结石来说，URL疗效优于ESWL。     

Comparative evaluation of Swiss LithoClast 2 and holmium:YAG laser lithotripsy for impacted upper-ureteral stones

PURPOSE: We prospectively compared the results of the Swiss LithoClast System with the holmium: yttrium-aluminum-garnet (Ho:YAG) laser for ureteral lithotripsy for management of upper ureteral stones. MATERIALS AND METHODS: Fifty patients were randomized to two groups: LithoClast classic 2 (n = 25) and Ho:YAG laser (n = 25) between January 2005 and January 2007. Procedure selection was decided by random chit allotment. All patients who successfully had ureteral dilatation (up to 10F) were included in the study. An 8/9.8F semirigid ureteroscope was used in all procedures with LithoClast 2, and either an 8F or 7F was used in patients who underwent laser lithotripsy. Patients were analyzed for fragmentation time, stone-free rate, stone up-migration, intraoperative complications, and auxiliary procedures. Results: Average stone size was 9.63 +/- 2.46 mm2 and 10.17 +/- 2.28 mm2 with overall stone-free rates of 84% and 88% (P = 0.41), respectively, for laser and LithoClast 2 groups. Stone up-migration was 24% and 16% (P = 0.82), mean stone fragmentation time was 9.82 +/- 7.58 and 7.86 +/- 3.25 minutes (P = 0.12), and stone fragments requiring ancillary procedures were 16% and 12% (P = 0.99), respectively, in laser and LithoClast 2 groups. Postoperative hematuria (up to 72 hours) was significantly (P = 0.04) prolonged in the laser group (36%) compared with the LithoClast 2 group (8%). Three patients in the LithoClast 2 group had instrument breakage. CONCLUSION: Both Ho:YAG laser and LithoClast 2 were equally efficient in managing ureteral stones with effective stone clearance, minimum morbidity, and reduced stone up-migration.     

A comparison of the FREDDY and holmium lasers during ureteroscopic lithotripsy

BACKGROUND AND OBJECTIVE: Two laser devices that are used today in endoscopic treatment of renal and ureteral calculi are the frequency-doubled double-pulse neodynium:YAG (FREDDY) and Holmium:YAG lasers. The mechanism of action of these lasers differs, thus conferring potentially different safety and efficacy profiles. The in vitro efficacy of these lasers in treating urinary stones has been explored, but to our knowledge no study compares the in vivo efficacy. The purpose of this study is to compare the stone-free and complication rates of the FREDDY and holmium lasers. STUDY DESIGN/MATERIALS AND METHODS: Subjects were included in the study (from January 2004 to September 2006) if they had adequate documentation of stone size and location, postoperative stone burden, and perioperative complications. Stone-free status was determined based on intraoperative findings and postoperative imaging. Complications included bleeding, ureteral perforation, any intraoperative event necessitating termination of the procedure, ureteral stricture, hydronephrosis, and admission to the hospital with a diagnosis related to the procedure. RESULTS: Sixty patients with adequate follow-up were identified. Thirty patients were treated with FREDDY and 30 patients with Holmium laser. Fisher's exact test was employed for statistical analysis. There was no significant difference in the average stone size between the FREDDY and Holmium groups, which were 6.7 mm and 6.1 mm, respectively. Stone-free rates in the FREDDY and Holmium groups were 76.7% and 93.3%, respectively, P = 0.149. The complication rates were 17.4% in the FREDDY group and 10% in the Holmium group, P = 0.667. CONCLUSION: The complication and stone-free rates did not significantly differ between the FREDDY and Holmium lasers, though there was a trend toward a higher stone-free rate and lower complication rate with the holmium laser. Holmium laser may be more effective than the FREDDY laser in fragmenting calcium oxalate monohydrate stones. The device and laser fiber costs were comparable.     

Experience in 3,500 patients with urinary stones treated with the Dornier HM-4 bath-free lithotriptor

During a 3-year period, hundreds of patients underwent ESWL treatment with the Dornier HM-3 and HM-4 lithotriptors operating at our institution. Our experience in 3,500 patients treated with the HM-4 bath-free lithotriptor is reported. Patients with radiolucent or cystine stones, stones larger than 3 cm or staghorn calculi, multiple stones with a total burden of more than 3 cm and those not amenable to follow-up were excluded from the study. The overall stone-free rate was 70.7% and 81% at 1 and 3 months, respectively. The stone-free rates at 1 and 3 months were further determined by the exact location of each stone within the urinary tract. Stone-free rates at 3 months ranged from 90.84% for renal pelvic stones to 71.08% for lower calyceal stones, while the stone-free rates for ureteral calculi ranged from 80.85% for upper third unstented ureteral stones to 92.92% for lower ureteral stones. The overall complication rate was 6.02% with a 1.2% post-ESWL intervention rate (ureteroscopy or placement of percutaneous nephrostomy or stent).     

Extracorporeal shock wave lithotripsy with a transportable electrohydraulic lithotripter: experience with >300 patients

OBJECTIVE: To review a multicentre experience of using a transportable lithotripter (STS-T, Medstone, Inc, Aliso Viejo, CA. USA) for treating patients with urolithiasis in all parts of the urinary tract. PATIENTS AND METHODS: In all, 326 patients with a total of 370 stones were treated as outpatients with the STS-T lithotripter. All patients received a single shock wave lithotripsy treatment and were followed after 4-6 weeks in the outpatient clinic, the primary endpoint being to determine the efficacy (as defined by the stone-free rate). Secondary objectives included establishing a database of patient demographic information, stone characteristics, stone location, procedural endpoints, and complication rates. RESULTS: In all there were 370 procedures, with a mean of 2394 shocks administered at an energy level of 24 kV. The mean treatment time was 51 min, excluding anaesthesia-induction time. The mean stone aggregate size was 8.2 mm; 62% of the stones were in the kidney while 38% were in various locations in the ureter. Of the treated stones, 90% had definite or probable evidence of fragmentation. The overall stone-free rate after one treatment with the STS-T was 52.8%. Of patients with residual fragments, most (61%) had fragments of <4 mm in aggregate diameter. The overall complication rate was 3.8%, the most common complication being postoperative pain. CONCLUSION: The Medstone STS-T lithotripter was an effective device for treating urolithiasis in all parts of the urinary tract. This system had a high margin of safety, as shown by the low complication rate. With no apparent sacrifice of efficacy compared to first-generation or fixed (not transportable) second-generation devices, the Medstone STS-T represents an important advance in the development of a truly transportable lithotripter.     

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

PURPOSE: We reviewed our experience with SWL for stones in abnormal urinary tracts and compared the results with those in normal urinary tracts. PATIENTS AND METHODS: The study group was composed of 2566 renal units (RU) treated on the Siemens Lithostar lithotripter at our SWL unit whose treatment and follow-up at 10 to 12 weeks were completed. Sixty-eight RUs (2.7%) belonged to 52 patients who had congenital upper urinary tract abnormalities. Logistic regression analysis was performed to analyze the impact of age, stone size, location, and the type of abnormality on the outcome of the SWL in the abnormal RU. The student t-, chi-square, and Fisher's exact tests were used for the comparison of stone load, number of treatment sessions, catheter placement, and success rates of the patients with normal and abnormal RU. Results of long-term follow-up for available patients (38 RU; 56%) were also evaluated. RESULTS: Age, stone load, stone location, and the type of abnormality did not have a statistically significant impact on the outcome of SWL for abnormal RU. The average stone load was 2.1 +/- 2.8 cm2 in the abnormal and 1.4 +/- 1.3 cm2 in the normal RU. Thus, the stone load was significantly higher in the abnormal RU (P < 0.05). In the abnormal group, 56% of the RU became stone free, 37% had nonobstructive and noninfectious clinically insignificant residual fragments < or = 4 mm (CIRF), and SWL failed in 7%. In the normal group, 78% of the RU became stone-free, 18.5% had CIRF, and SWL failed in 4%. There was no significant difference in the success rates in the groups if success was defined as stone free and CIRF together (P > 0.05). However, there was significant a difference when stone-free, CIRF, and failure rates were evaluated separately (P < 0.05). Recurrence, regrowth, and retreatment rates in abnormal RU were 50%, 37%, and 34%, respectively. CONCLUSIONS: Although the fragmentation rates were similar, clearance of the fragments was hampered in abnormal urinary tracts. Thus, especially for large stones, other endourologic treatment options should be considered. High recurrence and regrowth rates warrant careful monitoring and consideration for medical treatment during follow-up.     

Is ureteroscopy first line treatment for pediatric stone disease?

PURPOSE: We report our current outcomes for ureteroscopic management of pediatric stone disease. MATERIALS AND METHODS: We carried out a retrospective review of all ureteroscopic procedures for kidney or ureteral calculi performed between 2001 and 2005. Stone location and size, preoperative and postoperative stenting, intraoperative dilation, use of ureteral access sheath, stone-free rates and complications were noted. RESULTS: A total of 100 patients (58% female, mean age 13.2 years) underwent 115 procedures. Stones were located in the renal pelvis in 6% of patients, upper pole in 10%, mid ureter in 11%, lower pole in 17%, proximal ureter in 19% and distal ureter in 37%. Mean stone size was 8.3 mm (median 7.0), with a mean of 1.5 stones per patient. Preoperative stenting was used in 54% of patients, and a stent was placed postoperatively in 76%. Ureteral coaxial dilators and ureteral access sheaths were used in 70% and 24% of patients, respectively. There were no major intraoperative complications, although 5 patients required stent placement for ureteral perforation or extravasation. One patient had a ureteral stricture requiring ureteral reimplantation. Mean followup was 10.1 months (median 2.6). Stone-free rate was 91% on followup ultrasound, abdominal radiography or computerized tomography. Seven patients required staged ureteroscopic procedures to achieve stone-free status. While the number of percutaneous nephrolithotomy and shock wave lithotripsy cases remained stable, the number of ureteroscopic cases increased 7-fold during this period. CONCLUSIONS: Improved ureteroscopic access to stones throughout the pediatric urinary tract and stone-free rates that are comparable to the adult population have led to the adoption of ureteroscopy as first line therapy in children at our institution.     

The frequency-doubled double-pulse Neodym:YAG laser lithotripter (FREDDY) in lithotripsy of urinary stones. First clinical experience

Laser lithotripsy does not play an important role in urinary stone treatment, mostly due to ineffective fragmentation efficiency, and high purchase and maintenance costs. The aim of the following retrospective study was to show the clinical significance and efficiency of an innovative laser lithotripsy system for urinary stone treatment. Between November 1998 and October 1999, 48 patients were treated with the innovative frequency- doubled double-pulse Neodym: YAG laser lithotripter FREDDY. A total of 50 renal units were treated, 43 ureteroscopically, four ureterorenoscopically, three percutaneous-nephroscopically, and one bladder stone cystoscopically. With a median laser operation time of 5 min (range: 1-30 min) and a total procedure duration of 60 min (range: 15-180 min), a stone-free rate of upper ureteral stones of 62%, middle ureteral stones of 91% and distal ureteral stones of 100% were documented on the first day after treatment. In an observation period of 6 months, no complications were seen. In our experience Laser lithotripsy with FREDDY is an effective, simple and reliable method for the treatment of ureteral stones, with low purchase and maintenance costs. The extremely thin and highly flexible quartz fibre may extend the endoscopic spectrum to otherwise poorly accessible upper ureteral stones, the renal pelvis and renal calix stones. Therefore, a prospective validation study for comparison with ballistic lithotriptors is of great interest.     

Pediatric urolithiasis: 15 years of local experience with minimally invasive endourological management of pediatric calculi

PURPOSE: We sought to identify whether changes in technology and local practice have improved outcomes in the minimally invasive management of pediatric stone disease. MATERIALS AND METHODS: We reviewed retrospectively case notes and imaging from 1988 to 2003, noting treatment modality, stone-free rates, ancillary therapy and complications. RESULTS: A total of 122 children (140 renal units) with a mean age of 7.7 years underwent 209 extracorporeal shock wave lithotripsy (SWL) sessions. Stone size ranged from 6 to 110 mm. Stone-free rates were 84% for cases involving stones smaller than 20 mm, and 54% for those involving stones 20 mm or greater. For complex calculi 40% of patients were stone-free and 45% required ancillary procedures, with an overall complication rate of 26%. A total of 37 children (43 renal units) with a mean age of 6.4 years underwent 46 percutaneous nephrolithotomies (PCNLs). Stone size ranged from 8 to 155 mm. The overall stone-free rate was 79%. Of these patients 34% required ancillary procedures, with a major complication rate of 6%. A total of 35 children (35 renal units) with a mean age of 5.9 years underwent 53 ureteroscopies. Holmium laser was the most effective treatment modality in this group, with a 100% stone-free rate and no complications. CONCLUSIONS: For most renal stones smaller than 20 mm SWL was the most effective primary treatment modality. There was no statistical difference between the 2 lithotriptors for stone-free or ancillary procedure rate. The stone-free rate was dependent on stone size rather than type of lithotriptor. For renal stones 20 mm or greater and staghorn calculi we switched from SWL to PCNL as primary treatment, as stone-free rates were higher and the ancillary procedure and re-treatment rates were lower with PCNL. Electrohydraulic lithotripsy and pulse dye laser were initially used to treat ureteral stones. However, with the introduction of holmium laser technology we achieved higher stone-free rates and lower complication rates. Holmium laser lithotripsy is now used as a primary treatment modality for ureteral stones.