Ten years experience with piezoelectric extracorporeal shockwave lithotripsy of gallbladder stones

BACKGROUND: A critical review of the experience with extracorporeal shockwave lithotripsy (ESWL) of gallbladder stones is needed to clarify whether this method should continue to be applied to patients. METHODS: Patients with symptomatic gallbladder stones were treated by piezoelectric ESWL according to a prospective protocol between 1988 and 1997. ESWL treatment was limited to a maximum of three (solitary stones <20 mm diameter) to five sessions (larger solitary or multiple stones) and 3000 pulses per session. Univariate and multivariate analyses of pretreatment and treatment variables were performed to investigate their impact on fragmentation efficacy and stone clearance. A tree-based analysis was used to identify prognostically homogenous subgroups of individuals with maximum benefit from ESWL. RESULTS: Four hundred and eight patients, 76% female and 24% male, with a mean age of 46 (SD, 13) years, were selected for evaluation. Cox regression analysis identified three pretreatment variables with significant prognostic impact: (1) number of gallstones >1 (relative risk, 2.6 (95% CI, 1.9-3.5)), (2) size of stones >17 mm (1.7 (1.4-2.2)), and (3) computed tomography (CT) density of stones >55 Hounsfield units (H) (1.4 (1.1-1.8)). According to tree-based analysis, the stone clearance rate after 1 year was 85% (95% CI, 75-91%) for solitary stones <16 mm, 79% (70-86%) for solitary stones > or =16 mm with a CT density <84 H, 45% (32-55%) for solitary stones > or =16 mm with a CT density > or =84 H, and 42% (30-51%) for multiple stones. Five years after stone clearance, recurrence occurred in 43% of patients (95% CI, 39-47%). CONCLUSIONS: ESWL treatment showed an acceptable stone clearance in the case of small solitary gallbladder stones (<16 mm) or larger solitary stones with a CT density <84 H, but a very low success rate in the case of multiple stones. The poor long-term success, however, is an important argument against the use of ESWL of gallbladder stones.     

Extracorporeal shock wave lithotripsy (ESWL) for common bile duct stones]

We treated twenty-three patients with common bile duct stones (12 female, 11 male, mean age: 67.1 years) by Extracorporeal Shock Wave Lithotripsy (ESWL). The stones were focused by ultrasonic or choledochographic localization. The twenty-three patients received 53 ESWL treatments consisting of mean 2357 shocks per treatment at mean 18 kV. We performed ESWL in five cases with endoscopically unextractable common bile duct stones after endoscopic sphincterotomy (EST). In these cases, ESWL permitted stone disintegration and successful endoscopic extraction of the fragments. We performed ESWL in eighteen cases with common bile duct stones without EST. In fifteen of the eighteen cases (83%), fragmentation was achieved. The stone fragments were spontaneously discharged in ten cases (56%) after a median of 4 days following ESWL. In five cases, adjutant endoscopic procedures were performed. The complete fragmentation and the clearance rate for stones of diameter of less than 10 mm were higher than that for stones of diameter of more than 11 mm. In the cases with the stones of diameter of more than 10 mm, there is a very strong possibility that complete clearance is achieved by ESWL alone. No correlation was obtained for the effective results according to pretreatment number of stones. In eight of thirteen cases (62%) with gall bladder stones, complete clearance was achieved without EST. ESWL without EST can be thought as a rational treatment for preserving the function of papilla of Vater in the case of cholecysto-choledocholithiasis.     

Gallstone disappearance after extracorporeal lithotripsy and oral bile acid dissolution

Extracorporeal shock-wave cholelithotripsy was carried out in 135 symptomatic patients with radiolucent gallstones, followed by oral bile acid dissolution to assess the resultant stone disappearance rates. Fragmentation was satisfactory (all fragments less than 5 mm in diameter) in 34 patients (25%) after a single session of lithotripsy, and in 65 (48%) after multiple sessions. The overall satisfactory fragmentation rate was significantly higher in patients with single stones less than or equal to 20 mm in diameter when compared with those with larger solitary stones (71% vs. 38%, p less than 0.05), as it also was in all subjects with solitary stones when compared with those with multiple stones (60% vs. 34%, p less than 0.05). After 6, 9, and 12 mo of oral bile acid treatment, the stone-free rates were significantly higher in patients with satisfactory than in those with partial fragmentation (55% vs. 0%, 80% vs. 29%, and 90% vs. 33%, respectively; p less than 0.05). Only 1 of the 7 patients who had previously undergone endoscopic sphincterotomy for concomitant choledocholithiasis was free of stones after 1 yr of dissolution. During dissolution therapy, of the 102 patients in whom fragmentation had occurred, 1 (1%) developed mild acute pancreatitis, 23 (23%) suffered attacks of biliary colic, and 6 (6%) required cholecystectomy. We conclude that the result of fragmentation appears to be a major determinant of the success and rapidity of subsequent oral bile acid dissolution, and that when satisfactory, it allows for complete stone disappearance in most patients within the following year. A comparison of the present results with those of previous original studies suggests that to achieve such satisfactory fragmentation, patients should be selected on the basis of their stone characteristics, which optimally should present as solitary gallbladder calculi less than 20 mm in diameter. Furthermore, real-time ultrasonographic monitoring should be used during lithotripsy with a transducer centered along the shock-wave axis. Despite the innocuousness of the shock waves, the incidence of fragment migration and its possible complications, in our experience, emphasizes the need to restrict at present this nonoperative approach to the treatment of symptomatic gallstone disease.     

Aggressive extracorporeal shock wave lithotripsy of gall bladder stones within wider treatment criteria: fragmentation rate and early results.

Two hundred and twenty patients with a total of 412 gall bladder stones of between 8 and 38 mm in size were treated with extracorporeal shock wave lithotripsy, using the overhead module Lithostrar Plus. Fifty six per cent of stones were solitary (mean (SD) diameter 23 (5) mm) and 9.5% of the patients had more than three stones. Stones were successfully disintegrated in 218 patients (fragmentation size less than 5 mm in 80%, less than 10 mm in 19%). Some 65% of patients required one treatment and the rest two or three. A mean (SD) of 4100 (1800) shock waves with a pressure of 700 bar were applied. Twenty four to 48 hours after lithotripsy a transient but significant increase in serum transaminase activities (31%) and in bilirubin (29%), urinary amylase (27%), and blood leukocyte (62%) values was observed. In 29% of patients there was a transient microhaematuria, in 2% transient macrohaematuria, and in 25% painless petechiae of the skin. Ultrasound showed temporary gall bladder wall oedema in 13%, temporary distension of the gall bladder in 11%, and transient common bile duct distension in 8% after treatment. After discharge from hospital, 31% of patients complained of recurrent colic that responded to simple analgesics. Four to eight weeks after therapy, four patients developed biliary pancreatitis and 11 biliary obstruction that was managed by endoscopy. To date, 105 patients have been followed for over 12 months. Sixty one of these had a solitary stone, 17 had two, and 27 had three or more stones. A total of 59 patients, including 44 with a primary solitary stone, eight with two stones, and seven with three or more stones are completely stone free.     

Effect of extracorporeal shock-wave lithotripsy on gallbladder emptying in patients with solitary and multiple gallbladder stones

In a prospective study, we investigated the effect of extracorporeal shock-wave lithotripsy (ESWL) on gallbladder contractility and on fasting and residual gallbladder volume in patients with solitary and multiple gallbladder stones with stone densities<100 Hounsfield units (HU) and adequate gallbladder function. Twenty-five patients (seven males and 18 females, mean age 48.5±11.7 years) treated with ESWL were assigned to either group I, consisting of 13 patients with solitary stones<20 mm diameter, or group II, including patients with two to three stones and maximum stone diameter of 30 mm. ESWL was performed with the MPL 9000 lithotripter. Gallbladder ejection fraction was determined using the method of Dodds after a 12-hr fast and following application of a standard stimulative meal. Gallbladder volume was measured by ultrasound over 90 min at 10-min intervals before ESWL, then at 1, 30, 120, and 210 days after ESWL. At 24 hr after ESWL, residual gallbladder volume increased in group I from 7.4 ml to 13.9 ml (P=0.0567) and in group II from 6.5 ml to 20.2 ml (P=0.0076). Thereafter, residual volumes returned to pre-ESWL levels. In group II, post-ESWL fasting volumes were significantly increased over initial values at all time intervals. Correspondingly, only at 24 hr after ESWL, ejection fractions decreased from 73.1% to 64.9% in group I and from 76.5% to 62.7% in group II. No statistically significant differences in gallbladder contractility between the two groups were observed at any point of the follow-up period. ESWL exerts a no more than transient effect on gallbladder motility, regardless of stone count prior to ESWL. We postulate that changes in residual gallbladder volume and reductions in ejection fraction may be due to transitory disturbances in the gallbladder epithelium and resultant gallbladder wall edema.     

Fluoroscopically guided laser lithotripsy versus extracorporeal shock wave lithotripsy for retained bile duct stones: a prospective randomised study.

BACKGROUND AND AIMS: To compare extracorporeal shock wave lithotripsy (ESWL) and laser induced shock wave lithotripsy (LISL) of retained bile duct stones to stone free rate, number of therapeutic sessions, and costs. PATIENTS: Thirty four patients were randomly assigned to either ESWL or LISL therapy. The main reasons for failure of standard endoscopy were due to stone impaction (n = 12), biliary stricture (n = 8), or large stone diameter (n = 14). METHODS: An extracorporeal piezoelectic lithotripter with ultrasonic guidance and a rhodamine 6G laser with an integrated stone tissue detection system were used. LISL was performed exclusively under radiological control. RESULTS: Using the initial methods complete stone fragmentation was achieved in nine of 17 patients (52.4%) of the ESWL group and in 14 of 17 patients (82.4%) in the LISL group, or combined with additional fragmentation techniques 31 of the 34 patients (91.2%) were stone free at the end of treatment. In comparison LISL tended to be more efficient in clearing the bile ducts (p = 0.07, NS). Significantly less fragmentation sessions (1.29 v 2.82; p = 0.0001) and less additional endoscopic sessions (0.65 v 1.6; p = 0.002) were necessary in the LISL group. There were no major complications in either procedure. CONCLUSIONS: Compared with ESWL, fluoroscopically guided LISL achieves stone disintegration more rapidly and with significantly less treatment sessions, which leads to a significant reduction in cost.     

Extracorporeal shock wave lithotripsy: elimination of densely calcified gallstones and gallstones with calcified rims

OBJECTIVE: Until now, radiopaque gallstones have been excluded from extracorporeal shock wave lithotripsy (ESWL), because these stones in vivo are less sensitive to the forces that cause disintegration. In Japan there is a higher percentage of patients with radiopaque gallstones than in Western countries. Our purpose in working with patients in Japan was to warrant extensive indication of ESWL to radiopaque gallstones, especially densely calcified stones. DESIGN/METHODS: Retrospective analysis of clinical data. Patients were classified by computed tomography (CT) of stones. Group A consisted of 78 patients whose gallstones were densely calcified (CT attenuation values in Hounsfield units (HU), 473 +/- 323). Group B consisted of 22 patients whose stones had a calcified rim (CT attenuation values, 357 +/- 244). Ninety-eight patients received adjuvant dissolution therapy with ursodeoxycholic acid. Other recommendations, such as a glass of milk at night, were not given to the patients. SETTING: One university hospital and one general hospital. PATIENTS: One hundred consecutive Japanese patients with radiopaque stones in contractile gallbladder (CT attenuation values, > 150 HU, 447 +/- 310, mean +/- SD) were the subjects. With respect to the efficacy of ESWL, a degree of calcification for stones and its relationship with the rates of stone fragmentation and disappearance were assessed. Fragmentation to less than 3 mm in stone diameter was the aim, without limit of shock wave discharges and sessions. RESULTS: After ESWL sessions stones were fragmented successfully in 74 of the 100 patients (57 of the 78 patients in Group A, and 17 of the 22 patients in Group B). The mean number of discharges per patient was 10,435 +/- 8,726. The mean number of discharges for successful stone fragmentation of Group A (9,839 +/- 8,187) was not significantly different from that of Group B (11,376 +/- 6,344). One year after lithotripsy, 60 of the 100 patients were free of stones (45 in Group A, and 15 in Group B). CONCLUSION: It appears that patients with either densely calcified gallstones, or those in whom the stones have a calcified rim, are both suitable candidates for lithotripsy.     

Biliary lithotripsy with a new electromagnetic shock wave source

During a two-year study period 170 consecutive patients with gallbladder stones, suitable for lithotripsy, were treated with a new electromagnetic lithotriptor (Modulith) and oral bile acids; 142 patients were treated as outpatients. Sufficient fragmentation were obtained in 94% when 2112±137 shocks in 211 sessions with an energy setting of 17.8±0.8 kV were administered. Only 4/170 patients needed transient analgesia. Overall, side effects were transient and mild, but three patients developed biliary pancreatitis, which was treated by endoscopic sphincterotomy in two of them. A total of 67/100 patients were free of stones after one year. Subgroup analysis showed that 80% of the patients (stone diameter 5–20 mm), 64% (20–30 mm) and 65% (multiple stones), respectively, can expected to be free of stones after 12 months. In addition, 25 patients with large, endoscopically not extractable common bile duct stones were treated by lithotripsy with the Modulith. After endoscopic placement of a nasobiliary tube, stone targeting was possible by ultrasonography in 14 patients and by fluoroscopy in another 11 cases. In 23 of the 25 patients (92%) stone clearance by endoscopy was achieved after application of 2516±565 shocks with an energy preset of 18 kV. One patient refused further endoscopic procedures after successful fragmentation and another required local stone dissolution therapy. Side effects occurred more frequently (P<0.05) after lithotripsy of bile duct stones than of gallbladder stones, but they were without major clinical relevance. The new lithotriptor Modulith thus enables safe and highly effective lithotripsy of gallbladder calculi on an outpatient basis. Moreover, the device also allows successful lithotripsy of bile duct stones.     

Does computed tomography improve patients selection for extracorporeal shock wave lithotripsy (ESWL) of radiolucent gallbladder stones?

In 97 patients with radiolucent solitary gallbladder stones, the density of the calculi was evaluated by computed tomography (CT) prior to extracorporeal shock wave lithotripsy (ESWL). Sixty-three percent of the stones were isodense to bile (mean 48 +/- SD 11 HU), and 37% could be identified on CT-sections (maximal density 105 +/- 46 HU, mean density at the largest cross-section 53 +/- 31 HU). There was a slight trend toward better stone fragmentation and higher clearance rate in patients with isodense stones. However, the probability of complete fragment clearance was not significantly different in stones with a high or low CT-density. From these data we conclude that stone selection for ESWL and adjuvant bile acid therapy in patients with radiolucent solitary stones as assessed by oral cholecystography is only marginally improved by computed tomography.     

Results of extracorporeal shock wave lithotripsy of gall bladder stones in 693 patients: a plea for restriction to solitary radiolucent stones.

During a period of 24 months 693 consecutive patients with symptomatic gall bladder stones (526 males, 167 females; mean age 51 years, range 18-89) were treated by extracorporeal shock wave lithotripsy with a Piezolith 2300. The procedure was carried out on an out-patient basis without analgesics or sedatives. Concomitant chemolitholytic treatment (ursodeoxycholic and chenodeoxycholic acid 7.5 mg/kg/day each) was administered until three months after total fragment clearance for a maximum therapy period of 1.5 years. In 601 patients with radiolucent stones complete clearance of all fragments was obtained after three, six, 12, and 18 months in respectively 20, 41, 64, and 78%. Actuarial analysis of the subgroups according to the stone mass (size and number) selected an ideal patient population with solitary stones less than 20 mm diameter (84% stone free after one year). The results are significantly less good when the greater the number of stones or their maximal diameter increases. Treatment was interrupted in 3.6% of the patients. In 90 sludge or fragments remain present. Twenty five patients were lost to follow up for non-biliary reasons. Stone recurrence was 5.7% at one year and was observed both in patients with solitary and multiple stones. A cost effectiveness analysis suggests that laparoscopic cholecystectomy is the most effective and economic solution, although extracorporeal shock wave lithotripsy for solitary radiolucent stones less than 2 cm is cheaper than conventional cholecystectomy. Extracorporeal shock wave lithotripsy for multiple stones is the most expensive and least effective option.     

Pulverisation of calcified and non-calcified gall bladder stones: extracorporeal shock wave lithotripsy used alone.

Using a modified electromagnetic lithotripter (Siemens), extracorporeal shock wave lithotripsy (ESWL) was performed in 260 patients with gall bladder stones. Exclusion criteria for treatment were a non-functioning gall bladder, subcostal gall bladder location, and multiple stones occupying more than three quarters of the gall bladder volume. Stone pulverisation was the end point of ESWL. The number of shock wave discharges and sessions was not limited. Pulverisation was achieved in 250 patients (96.1%) after a median of three ESWL sessions (range 1-21). The number of sessions required depended upon stone composition and burden. More than three sessions were required in 60.2% of patients with calcified stones compared with 35.9% of patients with non-calcified stones (p < 0.001). 65.8% of patients with stones measuring more than 30 mm in total diameter required more than three sessions compared with 42.9% of patients with a stone burden less than 30 mm (p < 0.01). At 18-24 (8-12) months follow up, stone clearance was achieved in 94.3% (80.4%) of patients with non-calcified stones, compared with 89.5% (76.8%) in patients with calcified stones and in 75% (71.4%) of patients with a total stone diameter more than 30 mm compared with 95.7% (80.4%) for patients with a total stone diameter less than 30 mm (p < 0.05). ESWL related complications (gross haematuria) occurred in three patients. Thirty six (13.8%) patients experienced biliary colic; four had cholecystectomy, and five endoscopic papillotomy because of common bile duct obstruction. Stone recurrence was seen in 5.3% of patients over a follow up period of up to two years (median 16.6 months).     

When is ESWL of small calyceal stones indicated?

PURPOSE: To evaluate the indications for and the outcomes of extracorporeal shock wave lithotripsy (ESWL) of calyceal stones <5 mm, we prospectively studied a series of 25 patients scheduled for treatment. MATERIALS AND METHODS: Between January 1994 and June 1995, 15 males and 10 females with a mean age of 44 years (median 43; range 4 to 70 years) underwent ESWL of calyceal stones <5 mm using an unmodified HM3 Dornier lithotriptor. RESULTS: Indications for ESWL included 17 patients (68%) suffering from back and flank pain, 3 patients (12%) with gross hematuria and 1 patient (4%) with recurrent episodes of pyelonephritis. Six patients (24%) were asymptomatic. Evaluation 3 months after ESWL revealed that of the 17 patients with flank pain, 13 (76%) had complete resolution of pain and 4 (24%) had partial resolution of pain and there had been no further episodes of gross hematuria or pyelonephritis in the previously affected patients. At 3-month follow-up, of the 31 kidneys treated, plain radiography were available in 29; 20 (69%) were clear and 9 (31%) had small residual fragments. CONCLUSIONS: Calyceal stones <5 mm in maximum diameter can cause significant symptoms such as pain, hematuria and infection and should not be dismissed as inconsequential. When no other obvious cause is apparent, these small stones should be treated with a high likelihood of resolution of symptoms and clearance. ESWL should not be withheld in patients with small asymptomatic calculi who request or require treatment for fear of unexpected colic or stone growth.     

Optimized extracorporeal shockwave lithotripsy of gallbladder calculi: a prospective randomized therapy comparison

Is "pulverization" or "fragmentation" the best endpoint of extracorporeal shock wave application in ESWL of gallbladder stones? Has gallbladder motility a potential for the prevention of stone recurrence? METHODS: Prospective, monocentric study with randomization between the conventional treatment strategy (endpoint of shock wave application: fragments < or = 4 mm, concomitant oral chemolitholysis) and an intensified treatment strategy (endpoint of shock wave application: Pulverization, no chemolitholysis). Prevention of stone recurrence: At least once per month for one hour after a meal standardized position (back position, lowered chest). RESULTS: 34 patients, age 46 +/- 14 years (27 women, seven men) were included (F-ESWL: n = 18; P-ESWL: n = 16). Gallbladder motility, number, size and CT-measured calcifications of stones were comparable for both groups. P-ESWL patients received more shock wave pulses than F-ESWL patients and more treatment sessions. P-ESWL resulted in a better fragmentation and pulverization of stones was reached significantly more often (p < 0.05). The time period for stone clearance was significantly depending on the fragmentation result (pulverization: 0.7 months vs. fragments < or = 4 mm: 6.6 months vs. fragments > or = 4 mm: 8.0 months; p < 0.01). The stone free rate after twelve months was 87.5% for P-ESWL and 72.2% for F-ESWL (n.s.) and correlated significantly with the fragmentation result (p < 0.01). Pain sensations during stone clearance were significantly reduced by P-ESWL. Stonefree patients were followed up for 30 +/- 13 months, the total recurrence rate was 7.1%. CONCLUSIONS: Aiming for pulverization of gallbladder stones by means of intensified extracorporeal shock wave application is at least equal or in tendency superior compared to disintegration to fragements < or = 4 mm. Gallbladder motility might be useful to prevent gallstone recurrence after successful ESWL.     

Extracorporeal shock-wave lithotripsy and methyl tert-butyl ether for partially calcified gallstones

To explore the possibility that gallbladder stone fragments might be able to be safely dissolved using methyl tert-butyl ether immediately after extracorporeal shock-wave lithotripsy (ESWL), a feasibility study in 8 patients with one to four partially calcified gallbladder stones was performed. The gallstones averaged 2.2 cm in diameter (range 1.3-3 cm) and contained layered or diffuse calcium detectable by computed tomography scan only (7 patients) or plain film (1 patient). After a 5F (1.7 mm) pigtail catheter was placed percutaneously into the gallbladder, ESWL fragmentation was performed using a renal stone lithotriptor. The patients were under general anesthesia and in the prone position on a support gantry designed for gallbladder stone ESWL. Following ESWL, methyl tert-butyl ether was infused and aspirated via the gallbladder catheter until no further stone material was radiologically detectable or could be dissolved. After 8-26 h (mean = 13 h) of methyl tert-butyl ether therapy, no radiologically detectable gallstones remained in 6 of 8 patients. Shell fragments of three peripherally calcified stones in 1 patient and the densely calcified, predominantly pigment stone in a second patient were refractory to combined therapy. Both ESWL and treatment with methyl tert-butyl ether were well tolerated in all patients, although bile leakage after catheter removal occurred in 3 patients, one of whom was treated by cholecystectomy. Additional measures to prevent bile leakage may be advisable if these two modalities are to be used in tandem. We found no evidence, however, that predissolution stone fragmentation with ESWL predisposed the gallbladder to either mucosal damage by methyl tert-butyl ether or increased absorption of it.     

Long-term evaluation of extracorporeal shock-wave lithotripsy for cholesterol gallstones

BACKGROUND: Extracorporeal shock-wave lithotripsy (ESWL) is a treatment that preserves the gallbladder. Problems after ESWL treatment include stone recurrence and the development of biliary symptoms. METHODS: Two hundred and sixty-two patients with cholesterol-type gallstones, the best indication for ESWL treatment, and 42 control patients with cholesterol-type gallstones who received no treatment entered this study. We evaluated the factors associated with recurrence of gallstones after stone clearance and the development of biliary symptoms after ESWL treatment. RESULTS: The 3-, 5- and 7-year cumulative probabilities of gallstone recurrence were 20.6, 27.1 and 33.1%, respectively, with the recurrence probability significantly lower in patients with good gallbladder contractility. In patients with recurrence, ursodeoxycholic acid (UDCA) treatment was effective. In 69 patients with residual gallstones, the 3-, 5- and 7-year cumulative risks of biliary symptoms were 17.3, 24.9 and 30.5%, respectively. With residual gallstones, the risk of biliary symptoms developing was significantly lower in patients with a < or = 3 mm fragment size at the end of ESWL treatment and in those treated consistently with UDCA for 6 months or more after treatment with ESWL. The risk of biliary symptoms was significantly lower in ESWL-treated patients with residual stones who had a < or = 3 mm fragment size after treatment compared to those of control patients. CONCLUSIONS: Ursodeoxycholic acid was effective in clearing stones in patients with gallstone recurrence. In patients with residual stones, the fragmentation of stones to < or = 3 mm and UDCA administration effectively reduced the risk of subsequent biliary symptoms.     

Electromagnetic Shock Wave Lithotripsy of Gallbladder Stones: A Wide Range of Inclusion Criteria

From April 1988 until November 1990, 83 patients with symptomatic gallbladder stones were treated in the University Hospital "Dijkzigt" Rotterdam with extracorporeal shock wave lithotripsy (ESWL) followed by oral administration of bile acids (urso- and chenodeoxycholic acid). According to our inclusion criteria, patients with up to 10 stones without any limit to the size of the stone(s) were accepted for treatment. On average, these patients underwent two sessions of ESWL with an electromagnetic lithotriptor (Lithostar and Lithostar Plus, Siemens AG, Erlangen, Germany). Fragmentation of stones was achieved in 70/83 (84% patients). The best results were achieved in patients with a solitary gallstone (50% of these patients were stone-free 12 months after ESWL). Four percent of the patients with two to three stones, and 12% of the patients with four to 10 stones were free of stones 12 months after ESWL. Twenty-eight (34%) patients suffered from biliary colics after ESWL, and three patients (3.5%) developed pancreatitis. The administration of oral bile acids was complicated by transient diarrhoea in 15 (18%) patients. ESWL followed by oral bile acid therapy is a relatively effective and safe therapy for a highly select population of patients with gallbladder stones, which can be performed on an outpatient basis. Although the results for multiple stones were poor, the usage of wide inclusion criteria (up to 10 stones of any size) did not affect the success rate of ESWL for multiple stones.     

Extracorporeal biliary lithotripsy. Review of experimental studies and a clinical update

PURPOSE: To identify the technical and physical principles of extracorporeal biliary lithotripsy that are clinically relevant, and to review the patient series published to date. DATA IDENTIFICATION: Studies published since 1983 identified through a computerized search of MEDLINE and extensive hand searching of bibliographies in identified articles. STUDY SELECTION: Twenty-nine studies done in vitro or in animals and 21 studies in humans assessing biliary lithotripsy. DATA EXTRACTION: Based on an understanding of experimental determinants of fragmentation, we assess and explain the differences in the results from the clinical studies. The conclusions concerning overall clinical efficacy and safety are emphasized. RESULTS OF DATA ANALYSIS: Extracorporeal shock waves will safely fragment the gallstones of 80% to 100% of selected patients. However, the rate of satisfactory fragmentation (defined as the persistence of fragments only 3 to 5 mm in diameter or less) varies widely among the studies (22% to 78%); this discrepancy depends partly on differing characteristics of stone populations. For patients presenting with solitary stones of 20 mm in diameter or less, 90% will be stone-free within 6 to 9 months after lithotripsy; moreover, the success of lithotripsy determines the rapidity and extent of fragment dissolution. Bile-duct-stone lithotripsy is reserved for patients in whom endoscopic stone extraction and intracorporeal lithotripsy, with or without direct contact dissolution, have failed. Lithotripsy achieves ductal clearance in 55% to 85% of patients. CONCLUSIONS: Extracorporeal lithotripsy is safe and effective in selected patients, and has a definite role to play in managing patients with biliary stone disease. Its role in the coming years will depend on technical improvements in the generators, a tailored approach to complementary dissolution or extraction, and effective prophylactic therapy for preventing gallstone recurrence.     

Absence of apolipoprotein E4 genotype, good gallbladder motility and presence of solitary stones delay rather than prevent gallstone recurrence after extracorporeal shock wave lithotripsy

BACKGROUND/AIMS: Extracorporeal shock wave lithotripsy (ESWL) with adjuvant bile salt dissolution therapy may be successful in selected gallstone patients, but the considerable risk of recurrence is a major drawback. Apolipoprotein E4 genotype and impaired gallbladder motility have been identified as major risk factors for recurrence during short-term follow up. We have now examined their relevance during long-term follow up. METHODS: Eighty-four cholesterol gallstone patients (55 solitary and 29 multiple (two to ten) stones) were followed prospectively up to 10 years after complete stone disappearance. Various potential risk factors for recurrence were evaluated. RESULTS: Gallstone recurrence was found in up to 80% of patients at 10 years follow-up. Absence of the apolipoprotein epsilon4 allele, initial solitary stones, good gallbladder emptying (i.e. minimal postprandial volume < or = 6 ml) and 2-year postdissolution ursodeoxycholic acid prophylaxis (in ten patients) all delayed but did not prevent recurrence. In contrast, regular use of non-steroidal anti-inflammatory drugs (NSAIDs) was identified as an independent protective factor, with greatly decreased recurrence (at 10 years: 58 vs 93% in non-NSAID users, P = 0.03). CONCLUSIONS: Non-apolipoprotein E4 genotype, presence of solitary stones and good gallbladder emptying delay rather than prevent recurrence after initially successful ESWL. Regular use of NSAIDs may prevent recurrence.     

Extracorporeal shock wave lithotripsy of large difficult common bile duct stones: Efficacy and analysis of factors that favor stone fragmentation

Background and Aim:  Difficult common bile duct stones (CBD) are those not amenable to extraction by the standard technique of sphincterotomy followed by use of a Dormia basket or balloon. The role of extracorporeal shock wave lithotripsy (ESWL) in stone fragmentation and clearance of difficult CBD stones and the factors which favor fragmentation were prospectively evaluated in the present study.
Methods:  A total of 283 patients with large CBD stones were subjected to ESWL. A maximum of 5000 shocks was delivered per session until CBD stones were fragmented to less than 5 mm diameter. CBD was cleared by biliary endotherapy using a basket or balloon. Outcome was assessed by CBD clearance.
Results:  Total CBD clearance was achieved in 239 patients (84.4%) and partial CBD clearance in 35 patients (12.3%). Three or fewer sessions of ESWL were required in 74.6% of patients. Minor complications were seen in 45 patients (15.9%). There was no procedure-related mortality. Epidural anesthesia, shock frequency of 90/min, radiolucent calculi and presence of fluid around the calculus helped in better fragmentation.
Conclusion:  A high success rate, negligible complications and non-invasive nature of the procedure make ESWL a useful tool for removing large CBD stones.     

Combination therapy of gallbladder stones using extracorporeal shock waves and bile acids: results in relation to stone diameter and stone number]

420 patients were referred to our center for gallstone lithotripsy. 97 patients (23%) with radiolucent gallbladder stones (total diameter less than or equal to 3 cm) and intact gallbladder function were found suitable for extracorporal shock-wave lithotripsy. Disintegration of gallbladder stones was achieved in 92 of the 97 patients (95%). Chenodeoxycholic acid and ursodeoxycholic acid were used as adjuvant litholytic therapy. The therapeutic results were evaluated cumulatively in 90 patients after a follow-up of 10 months. 80% of patients with solitary stones (less than or equal to 20 mm in diameter (n = 46) had a stone-free gallbladder, whereas patients with solitary stones greater than 2 cm, less than or equal to 3 cm in diameter (n = 20) and multiple stones (n = 22) became stone-free in only 28% (p less than 0.01). During the observation period 21 patients (23%) experienced biliary colics, 2 (2%) mild pancreatitis, 2 (2%) showed fragment impaction in the common bile duct, and 17 (19%) displayed transient microscopic hematuria. Our results confirm previous studies showing that solitary stones sized up to 2 cm in diameter represent the best suited subgroup for extracorporeal shock-wave lithotripsy.