Extracorporeal Piezoelectric Lithotripsy Research Articles

Extracorporeal piezoelectric lithotripsy of intra- and extrahepatic bile duct stones

64 patients (27 men, 37 women; mean age 71 [27-90] years) with intra- or extrahepatic biliary stones, which could not be extracted endoscopically, underwent extracorporeal piezoelectric shock-wave lithotripsy (ESWL). The piezoelectric lithotripter which was used localizes the stones sonographically and the shock-waves are produced by a self-focusing sound generator consisting of 3,000 ceramic elements. The sonographic localization of the stones was successful in 57 patients (89%) and complete removal of stones was achieved in 49 (77%), after an average of 7,595 (1,000-30,800) shock-waves per patient. Spontaneous elimination of stone fragments occurred in 7 patients, while in 42 further endoscopic procedures (balloon catheter, Dormia basket, mechanical lithotripsy) were needed to remove stone fragments from the biliary tract. The only severe complication was cholangitis in two cases. It probably resulted from the associated lysis treatment. There was no case of pancreatitis and no death at 30 days. These data indicate that piezoelectric ESWL with sonographic stone localization is an effective method with few side effects for treating problematic biliary tract stones.

The piezoelectric lithotripsy of gallstones. The acute- and long-term results

Extracorporeal piezoelectric lithotripsy (PEL) with oral lysis (about 7.5 mg/kg urso- and chenodeoxycholic acid as single dose in the evening) was performed, according to a standardized treatment and follow-up protocol, in 219 patients (177 women, 42 men; aged 47 +/- 14 years) with symptoms of gallbladder stones. The average number of treatment sessions per patient was 2.0 +/- 0.8. Significantly fewer sessions with fewer shockwave charges were required in solitary gallstones of less than or equal to 20 mm diameter than in those of greater than 20 mm diameter and in multiple concrements (P less than 0.01). Fragmentation was successful in 99% of patients. Sedation and/or analgesia during PEL were required in only 2% of patients. There were no marked side effects during the treatment. The stone-free rate 12 months after the start of treatment was 76% in the group with solitary stones less than or equal to 20 mm, 75% with solitary stones greater than 20 mm and 64% for multiple stones. During the follow-up period 36% of patients had biliary colics and 3% had fragments impacted in the common bile duct. Biliary pancreatitis occurred in 1% of patients. PEL is an effective and sparing procedure in the treatment of selected patients with gallbladder stones.

Sectorial Technetium-99m-Dimercaptosuccinic Acid Scintigraphy for Monitoring the Effect of Extracorporeal Piezoelectric Lithotripsy for Calyceal Calculi on Regional Renal Function

Objective: To apply a semiquantitative method for analysis of technetium-99m-dimercaptosuccinic acid (^99mTc-DMSA) renal scintigraphy for monitoring the effect of extracorporeal piezoelectric lithotripsy (EPL) in patients with calyceal stones on regional kidney function and to check whether EPL had caused any deleterious effect on the target calyceal renal parenchymal function. Patients and Methods: Forty patients (mean age 35 years) suffering from calyceal stones documented by abdominal plain radiography, intravenous urogram or abdominal ultrasound were studied. All patients were treated by EPL. ^99mTc-DMSA scan was performed before and 4 weeks after EPL. Sector analysis involved calculation of the relative function of the target calyx to the function of the ipsilateral kidney and the relative function of the treated kidney to global renal function. Results: The stone sizes were 6–11 mm in diameter and 11 were located in the upper, 13 in the middle and 16 in the lower calyx. After EPL, the overall stone clearance rate was 85% (100% for calculi in the upper and middle calyces, 62% for lower calyces). The sector analysis did not show statistically significant change of the relative regional (calyceal) or whole kidney function between the pre- and post-EPL ^99mTc-DMSA scans. Using sector analysis, EPL appeared to be a safe modality and its usage was not associated with any untoward effect on calyceal or whole kidney function. Conclusion: Sector analysis of ^99mTc-DMSA renal scan is a simple semiquantitative method for monitoring regional changes of kidney function after EPL for treatment of calyceal stone.

Management of retained bile duct stones: a prospective open trial comparing extracorporeal and intracorporeal lithotripsy

Background: Endoscopic management of common bile duct stones has become the approach of choice, especially in patients with high surgical risk. Problems are encountered if there are large stones or a duct stenosis. For these difficult stones, shock wave technology serves as an alternative to surgical intervention. Methods: A total of 125 patients with common bile duct stones in whom conventional endoscopic treatment had failed were selected and treated either by extracorporeal piezoelectric lithotripsy (ESWL, n = 79) or intracorporeal electrohydraulic lithotripsy (EHL, n = 46). The average age of our patients was 70 years. Results: In the ESWL group visualization of the stones by ultrasound and ensuing treatment were possible in 71 out of 79 patients (90%); stones could be fragmented in 68 patients. The biliary tree could then be completely freed of calculi in 62 of 79 patients, a success rate of 78.5%. In the EHL group, stones were successfully fragmented in 38 of 46 patients; 34 patients (74%) eventually became stone free. Thirty-day mortality was zero in both groups. Combined treatment including ESWL, EHL, and intracorporeal laser lithotripsy was finally successful in 118 patients (94%). Conclusions: Endoscopic management in combination with the lithotripsy techniques described can be recommended as the method of choice for treating difficult common bile duct stones. A success rate of almost 100% and a mortality rate of 0% is now the established standard, even in elderly and unstable patients. (Gastrointest Endosc 1996;44:40-7.)

The effect of extracorporeal piezoelectric lithotripsy on the contractility of the human pelvicalyceal system

To assess the effect of extracorporeal piezoelectric lithotripsy (EPL) on the contractility of the human pelvicalyceal system. Contractions of the pelvicalyceal system were measured in 12 patients (mean age 55 years) before and after EPL. Pelvicalyceal pressure was measured via a Cope nephrostomy tube which had remained in situ following stone debulking procedures days or weeks earlier. All patients were treated using a Wolf Piezolith 2300 lithotripter. The pelvicalyceal systems of two patients were acontractile before and after treatment. Immediately after treatment, contractions were completely abolished in eight of the remaining 10 systems, and reduced in frequency in the other two. All 10 systems regained contractions 24 h after treatment. Piezoelectric lithotripsy temporarily abolishes upper urinary tract motility.

Clinical comparison of extracorporeal piezoelectric lithotripsy (EPL) and intracorporeal electrohydraulic lithotripsy (EHL) in difficult bile duct stones

Today, nearly 90% of common bile duct stones are extracted endoscopically. Problems are encountered if there are large stones or a duct stenosis. Extracorporeal piezoelectric lithotripsy (EPL) as well as intracorporeal electrohydraulic lithotripsy (EHL) serve as an alternative to surgical intervention for those few patients in whom endoscopic measures have failed. A total of 35 patients with common bile duct stones in whom conventional endoscopic treatment had failed were selected on the condition that stone visualization through ultrasound was possible and that the papilla was within easy reach of the endoscope. Patients fulfilling the inclusion criteria were randomly treated either by EPL or EHL. The average age of our patients was 73 years. The main reasons for failure of conventional endoscopy were due to the large size of the stones (13 patients), impacted stones (16), or the presence of a biliary stricture (6). In the EPL group, visualization of the stones by ultrasound and ensuing treatment were possible in 16 of 18 patients (89%); stones could be fragmented in 15 patients. In 13 patients, the biliary tree could then be completely freed of calculi; the success rate was 72% for all the patients (13 of 18). On average, the patients had 2.3 treatments on the lithotripter, and 3870 shock waves were applied per treatment. In the EHL group stones were successfully fragmented in 13 of 17 patients (76.5%). The average number of treatments was 1.4. Comparing both therapies, there was no difference in stone-free rates. In both groups, additional endoscopic interventions were necessary to clear the bile duct.(ABSTRACT TRUNCATED AT 250 WORDS)

Piezoelectric lithotripsy in the treatment of urolithiasis

The experience of the treatment of patients with urolithiasis by means of extracorporeal piezoelectric lithotripsy using the equipment of the Wolf firm the Piezolith-2300 and Piezolith-2500-10 apparatuses is generalized.

Quantitative Determination of Urinary Marker Proteins: A Model to Detect Intrarenal Bioeffects after Extracorporeal Lithotripsy

To detect the source of relevant acute intrarenal side effects after extracorporeal piezoelectric lithotripsy and its impact on repeat treatment, urinary excretion of highly specific marker proteins was determined before (day −1) and after (days 0, 1, 4, 7, 14 and 21) treatment. Marker proteins included high molecular weight α-2-macroglobulin, immunoglobulin G, albumin, α-1-microglobulin as well as the enzyme N-acetyl-β-ghicosaminidase. Of 50 patients who underwent 4,000 shock waves to caliceal stones (group 1) 15 were identically retreated after 5 (group 2) or 15 (group 3) days, respectively, to determine the shortest safe interval to repeat extracorporeal piezoelectric lithotripsy. The course of lithotripsy damage was also evaluated in 15 pre-damaged kidneys (group 4).The α-2-macroglobulin enhancement found in all groups on day 0 (p <0.005 to p <0.05) documented intrarenal bleeding from ruptured vessels. Ratios of α-2-macroglobulin/albumin greater than 2.00 on days 0 and 1 exclude a glomerular source of gross hematuria (groups 1 to 4). There was only slight acute tubular damage after extracorporeal piezoelectric lithotripsy (N-acetyl-β-glucosaminidase increase, p <0.05 for groups 1 to 4). Retreatment after 5 days did not enhance the amount of proteinuria compared to the same patients from group 1 (statistically significant at p <0.45 to p <0.10). Group 3 also showed a similar elevation of proteinuria as the identical patients pretreated 15 days previously. Thus, the data seem to suggest that early repeat sessions of extracorporeal piezoelectric lithotripsy are as safe as delayed retreatments. The course of proteinuria in group 4 did not suggest enhancement of extracorporeal piezoelectric lithotripsy damage in preinjured kidneys. The urinary marker α-2-macroglobulin detects intrarenal vessel ruptures, which are responsible for intrarenal hematomas, as evidenced by animal and human histology. A model is offered to understand and detect the most important parenchymal bioeffects to minimize the risk of injury.

Relation of Initial Radiographic Findings to Outcome and Treatment of Staghorn Calculi

In a 3-year period, 78 patients with staghorn calculi were treated by either percutaneous nephrolithotomy (PCNL) (N = 8), extracorporeal piezoelectric lithotripsy (EPL) (N = 18), or a combination of these modalities (N = 52). The latter group consisted of those who were originally selected for an attempt at monotherapy with EPL but required PCNL as part of their management (N = 22) -and those who had initial debulking of their calculi and subsequent EPL (N = 30). Overall, 46 (59%) of the patients were rendered stone free, and a further 11 (14%) had small (<4 mm) residual fragments. Of those selected for PCNL initially, 30 of 38 (79%) were stone free or had only small fragments, compared with 27 of 40 (67%) who began with EPL. The combination of initial PCNL and subsequent EPL as necessary provided the best results with the fewest complications. The radiographic density of the stone correlated well with rate of fragmentation on EPL, with the results suggesting that EPL monotherapy should be avoided for patients with calculi denser than the 12th rib. Total stone area provided little extra information in the initial assessment of large complex stones, but it was a more sensitive indicator of the bulk of residual fragments. Stones with detached caliceal segments were most successfully treated by EPL only after initial percutaneous debulking of the major pelvic component(s). We therefore believe that the selection of patients for EPL monotherapy is most satisfactory based on the density of the calculus and the anatomic drainage of that kidney rather than on stone bulk.

Extracorporeal Piezoelectric Lithotripsy in Unanesthetized Children

Extracorporeal piezoelectric lithotripsy is an effective method for treating renal pelvic stones in children. Treatment with the Wolf lithotriptor is essentially painless and can be performed without anesthesia on an outpatient basis. Real-time ultrasound is used to localize stones. In a 1-year period at the University of Utah, extracorporeal piezoelectric lithotripsy was administered to eight children with nine renal units. Of the eight children, aged 5 to 17 1/2 years, only two required sedation and only one received retreatment. No stents were placed. At 1 month posttreatment, all children were stone-free, and no significant complications occurred.

Extracorporeal piezoelectric shock-wave lithotripsy of salivary gland stones.

Piezoelectric lithotripsy was undertaken on 19 patients with salivary stones, with none of these patients requiring anesthesia, analgetics, or sedatives. All salivary stones were totally fragmented during first lithotripsy. Four months after treatment with extracorporeal shock waves, all patients were free of symptoms and, in 11 of the patients, no calculi could be found sonographically. The piezoelectric lithotripsy of salivary stones caused no serious side effects which could be proven by clinical, biochemical, sonographic, and magnetic resonance imaging (MRI) examinations. Extracorporeal piezoelectric lithotripsy is a new and promising nonsurgical therapy for selected cases of sialolithiasis of the parotid and submandibular glands.

Extracorporeal piezoelectric lithotripsy for retained bile duct stones.

Extracorporeal piezoelectric shock wave lithotripsy (EPL) was performed in 35 patients with endoscopically non-extractable stones. With this lithotripter, stones are visualized by ultrasound and shock waves are produced by a piezoelectric acoustic generator. The stones could be localized in 32 out of 35 patients. Fragmentation was achieved in 91.4% and complete stone removal in 77.1%. These results show that piezoelectric lithotripsy is also a useful method for the treatment of complicated bile duct stones, as already demonstrated for the electrohydraulically and electromagnetically generated shock waves systems. The piezoelectric system is especially useful in elderly and frail patients because no general anesthesia is needed and only 14% of cases require analgesia or sedation.

First Clinical Experience in Extracorporeal Piezoelectric Lithotripsy of Salivary Stones

A noninvasive and painless technique is now available for the treatment of salivary stones and is recommended as the first line of therapy by Heinrich Iro, MD, Gerhard Waitz, and Nikolaus Nitsche. These authors presented their findings of the first clinical experience in extracorporeal piezoelectric lithotripsy of salivary stones at the September 1991 annual meeting of the American Academy of Otolaryngology—Head and Neck Surgery in Kansas City, Mo. Until the advent of lithotripsy, the treatment options for salivary stones were to leave the stones in place, to excise them through an intraoral approach, or to excise the affected gland. First-generation lithotripters did not have the capability of having a focal volume small enough to allow for use in the head and neck region. With the advent of new-generation lithotripters, it is possible to have focal volume rate and strength compatible with use in the head and neck region. The authors

PCNL debulking: Our experience

Percutaneous debulking and subsequent ESWL treatment has proved a successful approach to complex stones. Out of 232 patients treated with PCNL from March 1984 to March 1992, 102 (45%) were managed by PCNL debulking and ESWL or EPL (Extracorporeal piezoelectric lithotripsy). Recently (Zingonia period 1988–1992) only 21 patients with bulky or staghorn stones were treated by combination therapy. In our series, there were 1.3 sessions of PCNL and 1.8 sessions of ESWL for each patient. We report a high frequency of retained stone fragments (45% at 3 months follow-up). Out of 21, 3 patients underwent further ESWL procedures because the fragments were conglobed. No complications occurred in present series. In the one case we observed a rise in serum creatinine. In our opinion debulking PCNL and ESWL is the treatment of choice in the following cases: burden pyelitic stones, staghorn stones larger than 3 cm. and smaller than 5 cm., partial staghorn filling renal pelvis and 1 calyx; short length of calyces; pyelitic portion exceeding caliceal mass; infected stones in working kidney, stone in solitary kidney larger than 2 cm and hard; previous surgery.

Effect of extracorporeal piezoelectric lithotripsy shock waves on renal function measured by Tc-99m-DMSA using SPECT.

Extracorporeal shock-wave lithotripsy has altered the therapeutic approach to urinary stone disease. Recently, a method was developed in which shock-wave generation is obtained piezoelectrically. To evaluate the effect of extracorporeal piezoelectric lithotripsy (EPL) on renal function, 20 patients were studied prior to and after EPL of renal calculi. Renal cortical function was evaluated by using a previously described and validated quantitative single photon emission computerized tomography (SPECT) method to measure individual absolute uptake of technetium-99m dimercaptosuccinic acid (Tc-99m-DMSA). Twenty kidneys were treated, and the 19 contralateral kidneys were without stone disease (1 patient had a single kidney). The absolute kidney uptake of Tc-DMSA in the normal kidneys was 21.4% +/- 6.2% before and 22.2% +/- 6.4% after EPL. For the treated kidneys the absolute update was 16.8% +/- 5.3% and 16.8% +/- 4.7% before and after, respectively. There was no statistical significant difference between pre- and post-treatment values. The absolute kidney uptake was significantly lower (p less than 0.01) in the treated than in the normal kidneys. This study indicates that the EPL procedure did not cause any damage to cortical function detectable by the DMSA uptake.

Piezoelectric Lithotripsy in the Treatment of Symptomatic Gallstone Patients A 12-Month Follow-up

Between January and May 1989, 65 patients with symptomatic gallbladder stones were treated with extracorporeal piezoelectric lithotripsy (EPL) and supplementary dissolution therapy with oral bile acids. In 98% of the patients, fragmentation of stones was achieved. On average, each patient received 3.18 treatments. In addition to attacks of colic and asymptomatic changes in laboratory parameters, one hematoma of the gallbladder and one of the liver were observed, together with pancreatitis and cholecystitis in two patients each. During the follow-up period, three patients developed symptomatic bile duct stones. An endoscopic retrograde cholangiopancreatography (ERCP) with papillotomy was performed on four occasions, while one female patient had to undergo urgent cholecystectomy for inflammation of the gallbladder and empyema. Six months after the initial treatment, 36 (55%) patients were free of stones, while the stone-free rate after 12 months was 64.5% (41 of 65). Ninety percent of the patients with a solitary stone less than or equal to 2 cm in diameter became stonefree within a year. Extracorporeal piezoelectric lithotripsy is clearly a feasible procedure for the treatment of certain gallstone patients.

Incidental Renal Carcinoma Discovered during Ultrasound Localisation of Renal Calculi for Extracorporeal Piezoelectric Lithotripsy

Extracorporeal shock wave lithotripsy is now widely used for the treatment of urinary calculi. Some lithotriptors, such as the Wolf 2300 Piezolith in this centre, use ultrasound imaging to localise and focus on to the stone prior to treatment. We have discovered 2 unsuspected renal carcinomas during this process, both of which were not revealed by the intravenous urogram sent with the referral. Prompt surgical intervention showed that both tumours were confined to the pathological specimen.

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.

Silent Obstruction after Extracorporeal Piezoelectric Lithotripsy

Extracorporeal piezoelectric lithotripsy (EPL) is frequently used to treat renal calculi. We are presenting a case that developed silent ureteric obstruction following three sessions of EPL of 4,000 shocks each. The obstruction was silent and asymptomatic, and was detected 6 weeks later on a routine follow-up renogram. The obstruction was due to an impacted stone fragment in the lower ureter. After release of the obstruction, the kidney function did not return to pre-therapy levels due to irreversible damage. This case demonstrates the importance of doing renograms before and within a few days after shock therapy for renal stones.

Pathologic-Anatomic Alterations in Human Kidneys after Extracorporeal Piezoelectric Shock Wave Lithotripsy

Pathologic-anatomic examinations of the kidneys from four patients—three adults and one child—were done after treatment with extracorporeal piezoelectric lithotripsy (EPL). Examination revealed alterations dependent on the number of shock waves administered. The pattern of renal lesions corresponded to the results known from animal studies. The renal alterations; i.e., hemorrhages and hematomas, were preferentially located at the corticomedullary junction. In comparison with the findings in laboratory animal studies, the lesions in human kidneys were decidedly minor after administration of the same number of shock waves.