EDAP LT-01 Research Articles

Analysis of Stone Fragility in Vitro and in Vivo With Piezoelectric Shock Waves Using the Edap LT-01

A total of 100 whole stones was fragmented in vitro at 3-minute intervals with piezoelectric shock waves using the EDAP LT-01 device until all fragments were less than 2mm. Larger stones and stones with a high computerized tomography attenuation needed longer treatments for fragmentation. Smoothly bulging stones with an even structure according to plain x-ray films were also more resistant to the shock wave treatment. Calcium oxalate monohydrate stones were not more difficult to break than other types of calculi. Stone fragments from 100 patients after extracorporeal shock wave lithotripsy were also analyzed. The average size of the fragments collected was less than 1mm. Larger stones produced larger fragments and required more treatment sessions.

Perirenal hematomas caused by SWL with EDAP LT-01 lithotripter.

A total of 419 calculi in the upper urinary tract of 402 patients were treated by SWL with the EDAP LT-01 lithotripter from July 1988 to September 1989. Subcapsular hematomas resulted in 17 kidneys of 16 patients, an incidence of 4.1%. On CT scan, fractures with subcapsular hematomas were observed in nine kidneys, and a retroperitoneal hematoma was observed in one patient. There was no significant difference in stone location and size, grade of hydronephrosis, number of shock waves, applied energy, or post-treatment fever between the groups with and without hematomas. However, the hematoma group revealed significantly (P < 0.01) higher incidences of pretreatment hypertension (> 160/95 mm Hg) and use of antiplatelet agents. It is difficult to detect some disorders of blood coagulation in ordinary laboratory studies in patients receiving low dosages of antiplatelet agents; and many drugs including analgesic and anti-inflammatory agents, calcium antagonists, coronary vasodilators, antiplatelet agents, beta-blockers, and lipid-regulating agents have antiplatelet actions. Therefore, particular care should be taken in SWL when a patient is using those drugs.

Middle Ureteral Stones: Results of In Situ Extracorporeal Shock Wave Lithotripsy with EDAP LT-01 Lithotripters

It has been stated that because middle ureteral stones are difficult to detect ultrasonographically, they are not amenable to in situ treatment with EDAP LT-01 lithotripters. In our hands, 15 of 79 patients (mean age 45.1 years) with middle ureteral stones averaging 11.2 mm were successfully treated with an EDAP LT-01 lithotripter with the stones in situ. With an Aloka SSD-650 hand probe, the common iliac vessels were visualized; while the patient was kept prone and using the vessels as a landmark, these stones were detected along dilated ureters and focused on by machine's self-contained probe. In three patients, the stones were not relocated by the EDAP probe because of obesity or nondilated ureters. Of 16 patients whose stones could be focused on by the probe, 15 were treated successfully. Our method of using the common iliac vessels as a landmark for locating and focusing on middle ureteral stones allows us to expand the treatment possibilities of EDAP LT-01 lithotripters.

Lithotripter Technology: Present and Future

Lithotripters can be categorized "low-cost" (Direx Tripter XI, Storz Modulith SL5, Northgate SD3, Siemens Lithostar Ultra, Dornier Compact), "second-generation" (EDAP LT01, Wolf Piezolith 2300, Technomed Sonolith 3000, Siemens Lithostar, Dornier MPL 9000), and "third-generation" (Storz Modulith SL20, Siemens Lithostar Plus, Dornier MFL 5000-u and MPL 9000-x, Wolf Piezolith 2500, EDAP LT02). The main features of third-generation lithotripters are a combined localization system allowing interdisciplinary shock wave lithotripsy; a wide energy range of the shock wave source, resultingin an efficacy similar to that of the Dornier HM3; and integration of the shock wave source and fluoroscopy unit in an endoscopic treatment table for multifunctional use. The advantages and disadvantages of the various shock wave sources, coupling, methods, localization systems, and handling of various third-generation lithotripters are outlined. A comparison of the possibilities and limitations of the different machines is given. A modification of the Clayman-Preminger efficacy quotient is introduced. Finally, the main factors determining the specific choice of a lithotripter are described.

Low early gallstone recurrence rate after successful extracorporeal lithotripsy in patients with solitary stones

Piezoelectric lithotripsy with the EDAP LT-01 machine combined with adjuvant bile acid therapy results in complete clearance of radiolucent gallstones in selected patients. We assessed stone recurrence rate in 84 patients with complete clearance of stone fragments and followed up at least 12 months after cessation of bile acid therapy (mean 17 months, range 12-33). Fifty-four patients had a solitary stone and 30 multiple stones. Bile acid therapy was continued for 3 months after complete fragment stones clearance which was ascertained by two consecutive ultrasound examinations. Stone recurrence was assessed by ultrasonography at 6 and 12 months, and then at least once a year. Gallstone recurrence occurred in 5 patients (6%) between 9 and 12 months with no further recurrence up to 33 months. The rate of recurrence at one year was 3.7% in patients with a solitary stone and 10% in patients with multiple stones. Only one patient with stone recurrence had recurrent biliary pain. We concluded that early gallstone recurrence rate after successful lithotripsy seems to be low in patients with solitary stones.

Stones in Horseshoe Kidneys: Results of Treatment by Extracorporeal Shock Wave Lithotripsy and Endourology

We report the results of 7 patients with calculi in a horseshoe kidney treated by extracorporeal shock wave lithotripsy (ESWL,**Dornier Medical Systems, Inc., Marietta, Georgia. 9 renal units) and percutaneous nephrolithotripsy (3 renal units) during a 3-year period. In the ESWL only group complete stone clearance was achieved in only 3 patients (50%) after an average of 3 sessions of therapy. On the other hand, complete stone clearance was achieved by percutaneous nephrolithotripsy with minimal complications. The poorer results with ESWL were due to difficulty in ultrasonographic localization of stones as well as poor drainage in these abnormal kidneys. Our experience with the Edap LT01 and the Sonolith 2000 lithotriptors suggests that while reasonable results are possible, treatment probably will require multiple sessions and the eventual outcome is less predictable than in normal kidneys. In contrast, the treatment of complicated stones in a horseshoe kidney presents no additional difficulty.

Proliferative Glomerulopathy Following Extracorporeal Shock Wave Lithotripsy in the Pig

Histopathologic changes after extracorporeal shock wave lithotripsy (ESWL) were studied in kidneys from four groups of nine pigs treated with an EDAP LT-01 (five pigs/group) or Dornier HM3 (four pigs/group) lithotripter, and sacrificed at time zero, 48hours, one week and one month. Treatment dosages increased consistently within each group. Samples from primary treatment area and opposite control kidney were processed routinely for light, immunofluorescence, and electron microscopy. Tubulointerstitial changes included hemorrhages at zero and 48hours and scars at one week and one month with both lithotripters. Glomerular mesangial cell proliferation started by 48hours and increased over one month in treated and control samples. Electron microscopy showed mesangial deposits and phagolysosomes. Immunofluorescence showed trace IgG, zero IgM, and 1−2+ C3. The conclusions were: 1) Mesangial cell proliferation associated with deposits of C3 and phagocytosis of cellular debris starts by 48hours post ESWL and increases thereafter, with both Dornier and EDAP lithotripters. 2) The pathogenesis appears to involve phagocytosis of circulating cellular debris and red blood cell fragments presumed to derive from breakdown of the hematoma caused by the lithotripsy.

Comparative Studies of Extracorporeal Shock Wave Lithotripsy by Dornier HM3, EDAP LT 01 and Sonolith 2000 Devices

During a 2-year period extracorporeal shock wave lithotripsy (ESWL††Dornier Medical Systems, Inc., Marietta, Georgia.) was done at our institution in 70 patients with the Dornier HM3, 113 with the EDAP LT 01 and 104 with the Sonolith 2000 lithotriptors. The size and location of stones were comparable in all 3 series, and all treatments were done by the same team of urologists. Complete fragmentation occurred in 79% of the patients treated by the Dornier, 82% treated by the EDAP and 79% treated by the Sonolith devices, with 3-month stone-free rates of 66, 67 and 58%, respectively. Auxiliary procedures were needed in 12% of the patients in the Dornier, 13% in the EDAP and 9% in the Sonolith groups. Repeat treatment was necessary in 4% of the Dornier group, 42% of the EDAP group and 26% of the Sonolith group.Therefore, all 3 lithotriptors are effective in stone disintegration and produce satisfactory results when selection criteria for ESWL are observed. The most significant difference among the 3 lithotriptors is the number of repeat treatments, which reflects the power and energy output of the lithotriptors.In conclusion, the Dornier HM3 device has the advantage of low repeat treatment rate and easier stone localization. The EDAP LT 01 unit has the advantage of lower treatment costs and anesthesia-free treatment with no irradiation. The Sonolith 2000 device has features of the other 2 lithotriptors with a superior ultrasound image.

Extracorporeal Shockwave Lithotripsy or Extracorporeal Piezoelectric Lithotripsy? Comparison of Costs and Results

One thousand patients with renal stones up to 3 cm in diameter were divided equally into 2 groups matched for age, sex and stone size. One group was treated on the Dornier HM3 lithotriptor and the other on the EDAP LT01. The results showed that for stones less than 1 cm both lithotriptors were equally effective, with a stone-free rate of 87.5% for the Dornier and 90.4% for the EDAP at 3 months. The success rate fell more steeply for the EDAP machine, however, to become 77.2 and 42.5% respectively as the stone size increased to 3 cm. Treatment time was longer on the EDAP lithotriptor and more sessions were required but patients preferred it to the Dornier. Running costs per patient were higher on the EDAP.

Treatment of gallstones with piezoelectric lithotripsy and oral bile acids

The efficacy of the combination of piezoelectric lithotripsy and oral bile acids in the treatment of gallbladder stones was assessed. Three hundred and sixty-three patients with symptomatic radiolucent gallstones in functioning gallbladder were treated in five medical centers using the same protocol with the EDAP LT 01 lithotripter. No anesthesia, analgesia or sedation was used. After one session of lithotripsy, fragmentation was observed in 89% of the patients, and satisfactory fragmentation (fragments less than or equal to 5 mm) in 29%. The satisfactory fragmentation rate was higher in patients with solitary stones less than or equal to 20 mm than in patients with solitary stones 21-35 mm or multiple stones (p less than 0.001). After multiple sessions (mean 1.6 session/patient, range 1-5) the overall rate of satisfactory fragmentation was 50%. After 12 months on oral bile acid therapy, complete clearance of the gallbladder was observed in 69% of patients with solitary stones less than or equal to 20 mm, 25% of patients with solitary stones 21-35 mm and 37% of patients with multiple stones. No complication was observed during the lithotripsy. During follow-up under bile acid therapy, there were five complications (1.4%): four patients had acute cholecystitis and one had mild, self-limited pancreatitis. We conclude that piezoelectric lithotripsy with the EDAP lithotripter is a safe and effective treatment which can be performed in outpatients. Satisfactory fragmentation and rapid disappearance of stones are obtained mainly in patients with solitary stones less than or equal to 20 mm.

Outpatient—Based Extracorporeal Shock Wave Lithotripsy using EDAP LT — 01

Between March 1988 and March 1990, 751 patients were treated with shock wave lithotripsy using EDAP LT — 01. Six hundred and eight patients had renal stones while 143 patients had stones located in the ureter. Because of difficulties in locating ureteric stones with ultrasound 92 % of them were pushed back to the kidney before treatment. The mean stone size was 10 mm, range 4 — 30 mm. Patients with stones bigger than 15 mm had a double J-stent placed before treatment. The mean number of treatments per patient was 1.7 (range 1 — 8). Sixtysix per cent of the patients with renal stones were completely stone-free after ESWL monotherapy. Another 5% became stone-free after auxiliary procedures in the ureter, because of retained fragments. Fragments equal to or less than 4 mm were retained in 14% of the patients with the renal stones. Of the patients with ureteric stones mobilised back to the kidney 95% were rendered stone-free after ESWL, Most patients experienced no or very little discomfort during the treatment and only 29% of them received analgesics. General or epidural anaesthesia was given to 1% of the patients. Because of the low demand for analgesia or anaesthesia, 99% of the patients with renal stones were treated on an outpatient basis. During the second year, 74% of the patients with ureteric stones were treated on an outpatient basis.

On the mechanism of kidney stone disintegration by acoustic shock waves

In the present study we have, by theoretical and experimental investigations, especially concentrated on the importance of acoustic streaming, transient cavitation and microstreaming in the fluid close to the stone. Artificial stones, round stones 20 mm in diameter made of Plaster of Paris or rectangular flat stones, 25 × 25 × 15 mm, were suspended in a water bath at the focus of an EDAP LT01 lithotripter. “Unprotected” stones were disintegrated while stones surrounded by a layer of silicone showed no or very small disintegration. For successful destruction of the calculus, it seems to be essential that the stones are surrounded by a liquid, i.e., water.

Initial EDAP LT-01 Lithotripsy Group Experience in the United States

The initial United States cooperative experience with the EDAP LT-01 second generation piezoelectric extracorporeal shock wave lithotriptor using ultrasonic guidance is presented. Particular to the machine are lack of radiation exposure, no need for anesthesia, a purely outpatient procedure, no electrocardiographic problems, a high degree of safety and a paucity of complications. The equipment is described briefly. The same machine currently is being used to destroy renal and biliary stones.The results are encouraging and highly comparable to the initial experience with the earlier machines. Fragmentation rates are approximately 86%, with destruction rates of 63.4% over-all. Ultrasound localization and monitoring proved surprisingly easy to learn and were increasingly less of a problem as experience was gained. No serious complications were observed, and there were no renal losses and no deaths. Only 3 cases of steinstrasse were noted among 461 with 633 stones targeted during 595 treatments.

A survey of the acoustic output of commercial extracorporeal shock wave lithotripters

A survey of the pressures and intensities generated by different commercial extracorporeal shock wave (ESWL) lithotripters is reported. The lithotripters included in the survey are the Dornier HM3, Wolf Piezolith 2200 and 2300, Siemens Lithostar, Technomed Sonolith 2000 and 3000, and EDAP LT-01. Measurements were made using a polyvinylidene difluoride (PVdF) membrane hydrophone in water. The zero crossing frequency of one complete cycle of the focused pulse from ESWL equipment is in the range 0.1 to 1 MHz. Spatial-peak temporal-peak positive and negative pressures up to 114 MPa and 10 MPa, respectively, have been measured and the rise times of the positive pressure half cycle at maximum output settings are 30 ns or less. The mean spatial-peak temporal-average intensity of the lithotripters is 5.0 × 10 2 W m −2 when operated at a pulse repetition frequency of 1 Hz. The spatial-peak pulse-average intensity ranges from 6.6 × 10 7 to 1.24 × 10 9 W m −2. The estimated acoustic energy in a single pulse (at the focus) at the maximum output setting of the lithotripters varies from 2.0 × 10 −3 J to about 9.0 × 10 −2 J. The beam area in the focal plane varies by a factor of 100 on different lithotripters and the temporal-peak pressure at the position of the skin at the entry point of the beam by a factor of 30. Measurement problems associated with hydrophone damage and the uncertainties in the hydrophone calibration at high pressures are discussed and an estimate of the total uncertainty in the absolute measurements of the spatial-peak temporal-peak positive pressure is given as ±36%.

A Foundamental Study of Lithotripsy with the Piezo Electric Wave

An extracorporeal shock wave type of lithotriptor using piezo-electric (EDAP LT-01), has variable output of shock-wave and frequency of ejection different from that of existing hydroelectric type. In the present study, we investigated the freqency of ejection and efficiency using a stone model in order to determine the effective freqency of ejection. Subjects and methods : Concrete moulded in a dish for an ice-making machine was usued as a stone model. The shock wave-were ejected int he frequency of 8 grades from 1.25 Hz/sec. to 160 Hz/sec. The effeciency of the lithotripsy was determined in terms of the time to complete destruction. Results : The time of destructionw as shortened linearly up to the frequency of 10 Hz/sec., but the efficiency of the destruction was not so increased even int he frequenct of more than 20 Hz/sec. Summary : It was concluded that the ejection of shock-wave through EDAP LT-01 was suitable in the frequency of less than 10 Hz/sec., because no anesthesia is required clinically in ejecting the shock-wave in the ferquency ranga. Efficiency of stone destraction was determined not only number of shock wave but also frequency of ejection.

Piezoelectric Extracorporeal Lithotripsy by Ultrashort Waves with the Edap LT 01 Device

A total of 433 extracorporeal lithotripsy procedures was performed for renal, ureteral and bladder stones by means of a system of ultrasonographic detection and piezoelectric destruction in 386 patients. The stones were detected easily in 87 per cent of the patients, difficult to detect in 10 per cent and impossible to detect in 3 per cent. Mean duration of treatment was 35 minutes. Mean number of piezoelectric waves was 2,700 at 1.25 per second. With a frequency of 1.25 to 5 per second, extracorporeal lithotripsy was performed without any local, regional or general anesthesia, and without premedication in 210 patients.Of the 217 patients with a renal stone reviewed at 3 months 161 (74 per cent) had successful results and 56 (26 per cent) failed therapy. Thirty patients (14 per cent) underwent 2 or 3 sessions. The morbidity was low: 2 per cent of the patients suffered ureteral obstruction, 1.5 per cent had subcapsular hematoma and 4 per cent had fever. No significant modifications of laboratory tests were necessary and no patient suffered renal failure.Of the stones 31 in the lumbar ureter, 15 in the pelvic ureter and 8 in the bladder were treated, with success rates of 87, 46 and 50 per cent, respectively. A total of 103 patients was treated on an outpatient basis. This outpatient treatment, together with the low cost and minimal maintenance of the apparatus, and the absence of anesthesia constitute a new progress in the treatment of renal stones.