A prospective randomized trial comparing 2 lithotriptors for stone disintegration and induced renal trauma

PURPOSE: We compare the efficacy and resulting kidney trauma of the HM3 (Dornier Medical Systems, Inc., Marietta, Georgia) and Lithostar Plus (Siemens, Issaquah, Washington) lithotriptors in a prospective randomized trial treating calix and renal pelvis stones. MATERIALS AND METHODS: Patients with a solitary renal pelvic stone 2 cm. or less in diameter or a solitary calix stone 1 cm. or less in diameter were randomized for treatment with the HM3 or Lithostar Plus. Stone disintegration and dilatation of the pyelocaliceal system were evaluated by abdominal plain x-ray and renal ultrasound 1 day and 3 months after treatment. Kidney trauma was determined by measurement of N-acetyl-beta-glucosaminidase and beta-galactosidase (NAG) in pretreatment urine and 4, 12-hour urine samples collected within the first 2 days after extracorporeal shock wave lithotripsy (ESWL, Dornier Medical Systems, Inc.). RESULTS: Of 167 patients with 176 stones 91 were randomized to the HM3 and 85 to the Lithostar Plus lithotriptor group. The preoperative stone burden was comparable in both groups. On postoperative day 1 patients treated with the HM3 or Lithostar Plus were stone-free or had fragments 2 mm. or less (91% and 65%, p <0.001), 3 to 5 mm. (8% and 25%, p = 0.003) and 6 mm. or greater (1% and 10%, p = 0.008), respectively. Patients treated with the HM3 had less posttreatment dilatation of the collecting system (p = 0.01). Obstructive pyelonephritis occurred in 1% of the HM3 and 8% of the Lithostar Plus group (p = 0.02). Re-treatment rate was 4% in the HM3 and 13% in the Lithostar Plus group (p = 0.05). Mean excretion of urinary NAG per treatment (including re-treatments) was comparable in both groups but NAG excretion in relation to stone volume and shock wave number 12 to 24 hours after ESWL was significantly higher in the HM3 group (p <0.05). At 3-months postoperatively 89% of the patients treated with the HM3 and 87% treated with the Lithostar plus were stone-free with no dilatation of the collecting system. CONCLUSIONS: This prospectively randomized study indicated that the HM3 is still the gold standard in regard to disintegration of pelvicaliceal stones. Stone disintegration with the HM3 is better with fewer shock waves, re-treatment rate is lower, and posttreatment dilatation of the collecting system and complications such as obstructive pyelonephritis are less than those with the Lithostar Plus. ESWL induced kidney trauma is minor and resolves within 2 days. The HM3 delivers more energy per shock wave into the kidney as assessed by urinary NAG.     

Second generation shock wave lithotripsy: experience with the Siemens Lithostar

In 1980, extracorporeal shock wave lithotripsy (ESWL) was incorporated as a nonsurgical method of stone removal in the cases of nephrolithiasis and rapidly found worldwide acceptance. Several devices commonly designated "second generation" lithotripters vs "first generation" Dornier HM3 are now under experimental or clinical trial. We report our clinical experience of ESWL using a Siemens Lithostar and compared it with that obtained using a Dornier HM3. One hundred patients were treated during the period of April through October, 1986 using an HM3, and 100 other patients were treated using a Lithostar from April to August, 1988. More cases were treated with a Lithostar than with a HM3. Nearly 10% of all patients treated by ESWL required additional therapeutic approaches (excepted ureteral stent) either with HM3 or Lithostar. However, in the cases of ureteral stone, with the Lithostar more cases required adjuvant procedures (TUL) than HM3. Significantly more shock waves were needed with Lithostar than HM3 for complete fragmentation of the same size of renal and ureteral stones. The stone-free rate during a one month period after ESWL was nearly the same for HM3 and Lithostar (HM3: 84.3%, Lithostar: 83.5%). Lithostar is a multifunctional lithotriptor which has most of the advantages required by the lithotripter.     

Extracorporeal shock wave lithotripsy in the management of pediatric urolithiasis

The main objective of this paper was to evaluate the efficacy and safety of the management of pediatric urolithiasis by extracorporeal shock wave lithotripsy (ESWL). Between November 1988 and July 2000, 165 renal stones, 53 ureteral stones, and 5 bladder stones were treated in 126 pediatric patients using Siemens Lithostar lithotriptor. The ESWL treatments ranging from 1 to 7 were needed per patient (mean: 2.1). One ESWL session was performed for 49.6% of stones, two for 24.6%, three for 13.0 %, four for 5.6% and > 4 for 8.2%. The success rate for renal stone units (asymptomatic fragments less than 4 mm) was 88.2%, stone-free rate was 49.0%. The stone-free rate for ureteral stone units was 87.5%, but was 75% for bladder stones. The overall results of ESWL treatment in 126 children was satisfactory: the success rate was 90.5%, stone-free rate was 51.6%, residual fragments > 4 mm were 9.5%. General anesthesia was required in 65 children (136 treatments) under the age of 10, and only in 18 children (40 treatments) in the age 11–14. Auxiliary procedures, such as double J stent and percutaneous nephrostomy (PCN) were used in 19 and 7 patients, respectively. Perirenal hematoma in one patient and hematomas in enteric wall in another one patient were the only major complications managed conservatively without consequences. Low energy lithotripsy with the Siemens Lithostar in our series of pediatric patients was safe and relatively effective.     

A Prospective Trial Comparing the Efficacy and Complications of the Modified Dornier HM3 and MFL 5000 Lithotriptors for Solitary Renal Calculi

A prospective randomized study of 198 patients was conducted to compare the efficacy of the modified Dornier HM3 lithotriptor to the MFL 5000 lithotriptor. Entrance criteria included solitary stones at any location within the upper collecting system that had not previously been treated with lithotripsy. Following lithotripsy the patients were evaluated by a blinded radiologist with a plain abdominal film, tomograms and renal ultrasound at 1, 4 and 12 weeks. Patients were classified at 12 weeks after lithotripsy as failing treatment if any stone fragments were imaged. Of the patients 170 were available for complete 3-month followup. No statistical or clinical difference in stone-free rates was apparent for calculi in the ureter or renal pelvis in either group. Of patients with lower caliceal stones 80 percent had no residual fragments visualized at 12 weeks when treated with the modified HM3 device versus 56 percent with the MFL 5000 lithotriptor (p = 0.05). Treatment time on the MFL 5000 unit was significantly prolonged compared with the modified HM3 device (0.7 hours versus 0.4 hours, respectively) resulting in fewer patients being treated in a given day (p less than 0.001). No statistical difference in complication rates could be found between the 2 machines. Steinstrasse were noted in 10 percent of the patients treated with the modified HM3 device and 6 percent of the MFL 5000 group. Subcapsular hematomas were noted in 4 percent of the MFL 5000 treatment arm compared to 1 percent in the modified HM3 group. Overall, the MFL 5000 lithotriptor was believed to offer no significant clinical advantage over the modified HM3 device in terms of lithotripsy efficacy, although the multifunctional table did offer more versatility for stone treatment. For a busy lithotripsy center, the modified HM3 lithotriptor is still the most efficacious.     

Endoscopic management of impacted ureteral stones using a small caliber ureteroscope and a laser lithotriptor

PURPOSE: We reviewed our experience with retrograde endoscopy using a small caliber ureteroscope and a laser lithotriptor in 104 consecutive patients with impacted ureteral stones and also analyzed the associated endoscopic findings. MATERIALS AND METHODS: From July 1993 to October 1999 we performed retrograde endoscopic treatment in 104 patients with impacted ureteral stones. Average maximum stone diameter was 15.2 mm. (range 2 to 110), and 9 patients had stones larger than 3 cm. Mean duration of impaction was more than 14 months and the longest was 10 years. We used 6.9Fr rigid or 6.9 to 7.5Fr flexible ureteroscopes and a pulsed dye laser or holmium:YAG laser lithotriptor. RESULTS: Of the 104 ureteral stones 100 (96.2%) were completely fragmented by a single endoscopic procedure. Although 1 uric acid stone could not be disintegrated by either the pulsed dye laser or electrohydraulic lithotripsy early in this series, it was discharged spontaneously 2 weeks after the procedure. Additional extracorporeal shock wave lithotripsy (ESWL*) was required in 3 patients who initially had stones larger than 3 cm. A month after treatment no patient had evidence of residual stones. Using adjuvant ESWL a 100% success rate was attained with minimal morbidity. Endoscopic observation revealed inflammatory polyps of the ureter in 22 patients (21.2%), and stricture adjacent to the stone in 16 (15. 4%). There were no significant complications. CONCLUSIONS: Using a small caliber ureteroscope and a laser lithotriptor we could treat the target stone in all 104 patients with adjuvant ESWL in 3 cases. Endoscopic lithotripsy seems to be effective first line therapy for chronically impacted stones which are frequently associated with chronic inflammation, polyps and strictures, and avoids the futile repetition of ESWL and problems related to the prolonged passage of stone fragments.     

Extracorporeal shock-wave lithotripsy (ESWL) monotherapy for stones in lower ureter.

Extracorporeal shock-wave lithotripsy (ESWL) has been accepted as the method of choice for most upper urinary tract calculi. However, in cases of stones in the lower ureter, ureteroscopic procedures have generally been preferred. Using the Dornier HM3 lithotriptor with modifications in the patient's position, we were able to successfully treat 155 unselected cases of lower ureteral calculi. The average stone size was 9.6 mm (range 5-23 mm). One hundred forty-three patients had stones located below the lower margin of the sacroiliac joint. These patients were placed in a supine position. The stones were visualized radiologically without use of a ureteral catheter in 78 percent of the patients; in 22 percent a ureteral catheter was inserted prior to ESWL to aid in stone localization. In 145 patients (94%) treatment was completed in one session; 10 patients (6%) required two sessions. Of the patients, 38 percent were free of stones one day after ESWL; 97 percent became stone free within three months, and only 3 patients required endoscopic manipulation, after ESWL. Twelve patients had stones in the midureter overlying the sacroileum. They were placed in the prone position, and the calculi were visualized with the aid of a ureteral catheter. All these patients became free of stones one month after treatment. There were no significant treatment-related complications except for bacteremia in 1 case. In view of the remarkable efficacy, negligible complication rate, and shorter hospital stay as compared to ureteroscopic stone manipulations, we recommend high energy ESWL as the primary monotherapy of mid and lower ureteral stones.     

Extracorporeal shock-wave lithotripsy with Lithostar lithotriptor.

Initial experience of extracorporeal shock-wave lithotripsy (ESWL) using the Lithostar lithotriptor is reported; 193 patients underwent 248 treatments for 210 stones. A total of 139 renal calculi (126 patients) and 71 ureteral stones (67 patients) were analyzed. Treatments were performed without anesthesia in 65 calculi (27.6%), with intravenous sedation in 91 (42.5%), and under epidural anesthesia in 34 calculi (29.9%). A three-month follow-up showed a success rate of 88.0 percent for renal calculi and 95.5 percent for ureteral calculi treated in situ. Renal stone fragmentation was achieved with a mean of 4,890 shocks at 17.4 kV and ureteral calculi were fragmented with a mean number of 4,798 shocks at a mean of 18.3 kV. Auxiliary procedures after ESWL were required in 2 patients with renal stones and in 1 with ureteral calculi. A comparison between stone size and number of shock waves required to achieve stone fragmentation revealed a linear relationship. Hospitalization was not necessary in 84.4 percent of renal calculi and 89.6 percent of ureteral calculi. Retreatments were necessary in 22 (15.8%) of the renal calculi (18 had 2 sessions, 3 had 3 sessions, and 1 had 4 sessions). Of the ureteral calculi, 8 (11.3%) underwent retreatment (6 had 2 sessions, 1 had 3 sessions, and 1 had 4 sessions). The low morbidity with a large number of patients treated on an outpatient basis, minimizing the need for anesthesia, demonstrated a favorable initial successful experience with the Lithostar.     

Electromagnetic extracorporeal shock wave lithotripsy in children

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

In situ extracorporeal shock wave lithotripsy for primary ureteric calculi

Objective. To determine the efficacy of the Lithostar lithotriptor for the in situ treatment of primary ureteric stones.Methods. We reviewed, retrospectively, our experience with 283 patients with primary ureteric stones treated with extracorporeal shock wave lithotripsy (ESWL) using the Lithostar lithotriptor. No attempts were made to manipulate the stones. The majority of the patients were treated using only intravenous analgesia. Auxiliary measures were used in 84 patients (29.6%). There were 112 patients (39.6%) with upper, 53 (18.7%) with middle, and 118 (41.7%) with lower ureteric stones.Results. A single ESWL session was needed for 200 patients (70.6%), two for 49 patients (17.3%), and more than two sessions for 34 patients (12%). Of the 248 patients who had adequate follow-up, 220 (88.7%) were stone free, 14 (5.65%) had some residual stone, while 14 (5.65%) patients failed to respond to the treatment. Patients' gender and body weight influenced the treatment and the clearance rate numerically without any statistical significance. The stone site was the most significant factor influencing the final result. Stones larger than 10 mm and the presence of hydronephrosis adversely affected the treatment.Conclusions. In situ ESWL of ureteral stones with the Lithostar device is a convenient and efficient method of treating calculi within the whole length of the ureter without the need for any manipulation.     

Extracorporeal shock wave lithotripsy for distal ureteral calculi: what a powerful machine can achieve

PURPOSE: We assessed the efficacy of extracorporeal shock wave lithotripsy (ESWL, Dornier Medical Systems, Inc., Marietta, Georgia) for distal ureteral calculi with the HM3 (Dornier Medical Systems, Inc.) lithotriptor. MATERIALS AND METHODS: A total of 585 consecutive patients with distal ureteral calculi were treated with ESWL using an unmodified HM3 lithotriptor. Of these patients 67 referred for treatment only for whom no followup was available were excluded from further analysis. The remaining 518 cases were followed until they were radiologically documented to be stone-free or considered treatment failures. Before ESWL additional procedures were performed in 144 patients, including stone push back, ureteral catheter or Double-J (Medical Engineering Corp., New York, New York) stent placement, percutaneous nephrostomy, ureteral endoscopic maneuvers or stone basket manipulation. A total of 374 patients needed no preliminary treatment before ESWL. RESULTS: Of the 518 patients 469 (91%) were successfully treated with 1 ESWL session, while 49 (9%) needed 2 or 3. Manipulation after ESWL was performed in 22 cases, including stent placement, percutaneous nephrostomy, ureteral endoscopic stone removal and a stone basket procedure. On day 1 after ESWL 327 patients (63%) were stone-free, 158 (30%) had less than 5 mm. fragments and 33 (7%) had more than 5 mm. fragments. At 3 months the stone-free rate increased to 97%. CONCLUSIONS: These data show that ESWL for distal ureteral calculi with the powerful unmodified HM3 lithotriptor has a high success rate with a low rate of minimally traumatic manipulations before and after intervention. Results in terms of the re-treatment and stone-free rates are superior to those of any other second or third generation lithotriptor and comparable to the results of the best ureteroscopic series.     

Noninvasive anesthesia,analgesia and radiation-free extracorporeal shock wave lithotripsy for stones in the most distal ureter: experience with 165 patients

PURPOSE: Spontaneous ureteral stone passage often causes severe renal colic, especially when the stone passes through the narrow ureteral orifice. In these situations noninvasive anesthesia-free, analgesia-free and radiation-free extracorporeal shock wave lithotripsy (ESWL) (Dornier Medical Systems, Marietta, Georgia) is a valuable tool. It can be performed at any time without needing any further patient preparation. MATERIALS AND METHODS: A total of 165 patients underwent ESWL using the Lithostar Ultra device (Siemens, Erlangen, Germany). Only ureteral calculi within 5 cm. of the ureterovesical junction were included in this study. Patients were treated while supine and stones were localized by ultrasound through the filled bladder without x-ray exposure. Treatment was started without anesthesia or analgesia and analgesics were administered only at patient request during treatment. RESULTS: Of the patients 93% were treated without anesthesia or analgesia and 7% required a single intravenous dose of 25 mg. pethidine. Postoperatively renal colic developed in 40 patients (24%). In 4 cases (2.4%) renal drainage was required for analgesia resistant pain or obstructive pyelonephritis. On day 1 after ESWL 90% of the patients were stone-free or had fragments 2 mm. or less, while 10% had residual fragments 3 mm. or greater. Of all patients 7% were re-treated once. At 3 months postoperatively 129 of the 130 evaluable patients (99%) were stone-free. CONCLUSIONS: ESWL of stones located in the most distal ureter using the Lithostar Ultra device is effective, safe and radiation-free. It is done without anesthesia and in most cases without analgesics. This simple and noninvasive procedure is an excellent first line treatment modality for prevesical stones and it represents a valid alternative to conservative management or invasive endoscopy.     

Treatment of steinstrasse with repeat extracorporeal shock wave lithotripsy: experience with piezoelectric lithotriptor

Among 958 patients with renal stones who underwent extracorporeal shock wave lithotripsy (ESWL) monotherapy using an EDAP-LT01 piezoelectric lithotriptor steinstrasse developed in 55 (5.7%). Of these 55 cases stone fragments passed spontaneously in 35 (63.6%) and were treated successfully (no residual stone fragment in ureter) with repeat ESWL in 18 (32.8%). Only 2 patients (3.6%) required ureteroscopic management or open ureterolithotomy. Therefore, repeat ESWL is considered a good initial method to treat complicated steinstrasse.     

ESWL monotherapy for large-volume renal calculi: efficacy and morbidity

We assessed the efficacy and morbidity of extracorporeal shock-wave lithotripsy (ESWL) monotherapy in the treatment of 25 consecutive patients with large-volume renal calculi (surface area greater than or equal to 5.0 cm2). Eighteen of the calculi were infection (struvite) stones and 7 were sterile stones. In 21 cases internal ureteral stents were positioned before ESWL, but no patient underwent pretreatment percutaneous nephrostomy (PCN) or percutaneous nephrostolithotomy (PNL). An average of 2.1 procedures including ESWL, PCN, or ureteral interventions were required to achieve a stone-free renal collecting system and ureter, or residual stone particles less than 4 mm in diameter confined to the renal collecting system. Sixty percent of the patients required no ancillary procedures after ESWL. There were no differences in the mean duration of hospitalization, need for post-treatment ancillary procedures, time to clearance of ureteral fragments, and incidence of residual stone particles among patients with infection and sterile stones. Of 23 patients observed greater than three months (mean 10.9 mos) after ESWL, 43 percent had residual stone particles in the renal collecting system. Expansion of these particles or stone recurrence in the absence of residual particles has not been observed. We conclude that large volume renal calculi may be managed effectively and safely with ESWL monotherapy.     

Adjunct controlled inversion therapy following extracorporeal shock wave lithotripsy for lower pole caliceal stones

The lower calix is responsible for a significant number of kidneys with residual stone fragments after extracorporeal shock wave lithotripsy (ESWL*). To compare the effectiveness of controlled inversion therapy as an adjunctive method to the elimination of calculous fragments, 42 patients who had undergone treatment for lower caliceal stones with a Siemens Lithostar lithotriptor were reviewed. Of the patients 25 had no adjunctive therapy and 17 underwent controlled inversion therapy. The success rate, effectiveness quotient and complication rate were analyzed. Followup consisted of ultrasound and a nephrotomogram 1 day and 1 to 3 months postoperatively. Complete removal of all stone fragments was achieved in 84% of the patients without an adjunctive maneuver and in 64.7% of those treated with controlled inversion therapy. The effectiveness quotient was 72.4% and 35.5%, respectively. The group treated without adjunctive therapy had fewer retreatment sessions and a lower complication rate. There were no complications related to the controlled inversion therapy and patient acceptance was generally enthusiastic. We conclude that controlled inversion therapy did not improve the results of ESWL for lower pole caliceal calculi.     

Extracorporeal shock-wave lithotripsy of bile-duct stones. Initial Swedish experience

Fifteen patients with mean age 74 (range 34-94) years were treated with extracorporeal shock-wave lithotripsy (ESWL) for bile-duct stones (intrahepatic in 4 cases) following failure of surgical or endoscopic treatment. A Dornier HM3 lithotriptor was used, and in all cases the ESWL session was preceded by establishment of external biliary drainage (endoscopic nasobiliary in 9, percutaneous transhepatic in 2 and a surgical T-tube in 4 cases) for radiologic positioning of stone. Endoscopic (14 cases) or surgical (1 case) sphincterotomy was done to facilitate spontaneous passage or endoscopic removal of fragments after ESWL. General anesthesia was not needed during the average 50 (range 25-65) min required for performance of ESWL. The number of delivered discharges was 750 to 2,100 and the generator voltage varied from 14 to 17 kV. Disintegration of stone was good in 12 cases and partial in two. Ten patients remain stone-free, five after spontaneous passage, and five after endoscopic extraction of fragments. There were few complications. ESWL may be useful in high-risk patients with failed endoscopic treatment of bile-duct stones and for management of intrahepatic stones.     

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.     

Shock wave lithotripsy is effective and safe for distal ureteral calculi in children

We evaluated the effectiveness of the Siemens Lithostar Modularis lithotriptor for the management of distal ureteric calculi in children. Between 2004 and 2006, 29 children with distal ureteric calculi were treated in our stone center with the Siemens Lithostar Modularis (Siemens Medical Solutions, Inc.) Effectiveness of lithotripsy, retreatment and efficacy quotient rates, and complications were assessed. The series consisted of 18 (62%) boys and 11 (38%) girls with an age range of 1-13 years (average age 7.0 +/- 3.5). Under fluoroscopic guidance, children were treated with a maximum 3,000 shocks at an average of 2.2 +/- 0.3 kV. Mean stone size was 8.2 +/- 3.2 mm (range 4-18). Success was defined as the lack of any visible stone fragments on posttreatment radiological evaluation. The mean number of sessions required was 1.5 +/- 0.8/patient (range 1-4). Complete clearance rate at 3 months was 86.2%. Re-treatment and efficacy quotient rates for distal ureteral stones were 41.4 and 55.6%, respectively. Complications such as urinary tract infection or steinstrasse occurred in 2 (6.9%) patients. Minor complications included petechial skin hemorrhage at the site of entry of shock waves in all patients. Our results show that shock wave lithotripsy for distal ureteral calculi with the Siemens Lithostar Modularis lithotriptor has a high success rate (86.2%) and efficacy quotient (55.6%) with negligible complications in children.     

Mobile versus fixed site lithotripsy.

The efficacy of a mobile Dornier HM4 lithotriptor, was compared with that of a fixed site Siemens Lithostar. A total of 115 calculi in 98 patients were treated, 55 on the mobile Dornier and 60 on the Lithostar. The groups were similar except for stone size, the mean of the Lithostar group being 11 mm compared with 7.7 mm in the Dornier group. Fragmentation rates were not significantly different, 88% and 75% on the mobile and fixed site machines, respectively and, at 3 months follow-up 66% and 46% were stone free or with fragments of less than 2 mm. There were no serious complications, and the incidence of mild complications was similar in the two groups. We conclude that the mobile Dornier HM4 is an effective lithotriptor and can offer several advantages over fixed site machines.     

Clinical Implications of Clinically Insignificant Stone Fragments After Extracorporeal Shock Wave Lithotripsy

Purpose

We determined the natural history and clinical significance of small, asymptomatic, noninfection related stone fragments after extracorporeal shock wave lithotripsy (ESWL*).

Materials and Methods

We prospectively followed 160 patients with 4 mm. or less asymptomatic calcium oxalate/phosphate stone fragments after ESWL for 1.6 to 88.8 months (mean 23) to stone-free status, censorship or intervention. Kaplan-Meier estimates of probability to anatomical stone-free, decreased or stable status were determined as well as the probability of symptomatic episodes or required urological intervention.

Results

Stone-free status or a decreased, stable or increased amount of residual stone occurred in 38 (23.8 percent), 26 (16.3 percent), 67 (41.9 percent) and 29 (18.1 percent) of the 160 patients, respectively. At 5 years after ESWL the probability of a stone-free, stone-free or decreased status, or stone-free, decreased or stable status was 0.36, 0.53, and 0.80, respectively. A total of 91 patients (56.9 percent) remained asymptomatic while 69 (43.1 percent) had a symptomatic episode or required intervention 1.6 to 85.4 months (mean 26) after ESWL (probability estimated at 0.71 at 5 years).

Conclusions

While patients with small noninfection related stone fragments after ESWL may be followed expectantly, a significant number will require intervention or have symptomatic episodes within 2 years. The term clinically insignificant applied to any residual stone after ESWL is likely a misnomer.     

Extracorporeal shock wave lithotripsy monotherapy in the treatment of staghorn calculi

From October, 1987 to September, 1989, 53 staghorn calculi of 51 patients underwent extracorporeal shock wave lithotripsy (ESWL) monotherapy by using Dornier HM3 lithotriptor. All patients were treated with double J stenting preoperatively. Mean number of shock waves was 6092 and mean number of sessions was 2.1. In 52 out of 53 kidneys (98%), the stones were disintegrated completely. Complete removal of the stone were observed in 29 kidneys (55%) 3 months after the last ESWL treatment. Complications consisted of fever attack (more than 38 degrees C) (26 patients), ileus (2), subcapsular hematoma (2) and gastrointestinal hemorrhage (1). They could be conservatively treated except one case with percutaneous nephrostomy. Supplementary procedures for the stone street were necessary in 23 patients. They consisted of ESWL (16 patients) and transuretheral lithotripsy (7). The indication of this procedure for the treatment of staghorn calculi was also discussed.