Piezo-ceramic lithotripsy of gallbladder stones: initial experience in 38 patients

Evaluation of hepatocyte function after extracorporeal shock wave lithotripsy with hepatobiliary scintigraphy

OBJECTIVE

Extra corporeal shock wave lithotripsy is a promising and effective therapy mode in the nonsurgical therapy of gallstones. This prospective study was conducted to investigate the effects of ESWL on hepatocellular function, using quantitative hepatobiliary scintigraphy, serum aminotransferase, alkaline phosphatase (ALP), amylase (AML), and direct and indirect bilirubin levels.

METHODS

The study consisted of 22 patients with ultrasonographically documented gallstones. Hepatobiliary scintigraphy was applied to all patients before ESWL and biochemical tests were performed. Scintigraphy and biochemical tests were repeated in 16 patients 24 h, in seven patients 72 h, and in six patients 1 wk after ESWL. The hepatic extraction fraction (HEF) was calculated using deconvolution analysis of scintigraphic data.

RESULTS

All patients' pre-ESWL biochemical tests and HEF values were within the normal range. The 24- and 72-h post-ESWL aminotransferase, ALP, and AML levels and HEF values were significantly different from pre-ESWL values (p < 0.05). After 1 wk this difference disappeared. Decreased HEF values were observed in 50% of patients 24 h, in 71.7% of patients 72 h, and in 16.6% of patients 1 wk after ESWL. A direct relationship was also observed between the number of shocks applied and the degree of impairment in HEF values.

CONCLUSION

Transient hepatocellular dysfunction, which usually occurs after ESWL, can be demonstrated and monitored using quantitative hepatobiliary scintigraphy.

Gallbladder stone recurrence after medical treatment. Do gallstones recur true to type?

Medical treatments that dissolve or remove gallbladder stones but leave the gallbladder in situ have the disadvantage of gallstone recurrence. Little is known about the composition of recurrent stones or whether they recur true to type. In 21 patients with recurrent stones detected 5-74 months (mean +/- SEM, 26 +/- 4 months) after being rendered stone-free with dissolution therapy (N = 15) or percutaneous cholecystolithotomy (N = 6), we compared pretreatment and postrecurrence gallstone number, maximum gallstone attenuation scores measured by computed tomography (CT) and, in 13, the dissolvability of the recurrent stones with oral bile acids +/- extracorporeal shock-wave lithotripsy. Before treatment, five patients had solitary and 16 had multiple stones but on recurrence, the gallstones differed in number from the primary stones in 10 of the 21 patients. As a result of patient selection, before dissolution, the primary stones were all radiolucent with maximum CT scores of < 100 Hounsfield units (HU) (mean 45, range 10-84 HU). On recurrence, the stones were again CT-lucent in 13 of the 15 patients but were CT-dense in the remaining two (118 and 176 HU). Initially, all six patients treated by percutaneous cholecystolithotomy had radio-opaque stones, with a mean CT score of 459 (range 100-969) HU. However, on recurrence, only one had calcified stones (HU 140); the remaining five had CT-lucent stones (16-98 HU, P < 0.05). Of the 13 patients whose recurrent, plain x-ray-lucent and CT-lucent stones were treated with oral bile acids +/- lithotripsy, 12 (92%) showed evidence of gallstone dissolution. We conclude that gallbladder stones do not recur true to type in up to two thirds of patients. However, irrespective of original gallstone composition, recurrent stones are usually radio- and CT-lucent, presumed cholesterol-rich, and therefore potentially dissolvable with oral bile acids.

Percutaneous cholecystolithotomy: risks, benefits, and long-term outcome

BACKGROUND

For symptomatic patients with gallbladder stones and a patent cystic duct who wish to retain their 'functioning' gallbladders, percutaneous cholecystolithotomy (PCCL) offers an alternative to open or laparoscopic cholecystectomy. However, there are few data on the risks and benefits of this approach or on the long-term outcome.

METHODS AND RESULTS

In 21 patients with symptomatic calcified gallstones, PCCL was successful (gallstone clearance) in 17 (81%). Four to 62 (median, 35) months after clearance 9 of the 17 remained symptom-free and stone-free, whereas 4 developed biliary sludge at 7, 30, 32, and 35 months, 2 of whom subsequently developed gallstones. In four other patients gallstones recurred without evidence of preceding biliary sludge at 9, 16, 19, and 27 months, corresponding to an actuarial gallstone recurrence rate at 36 months of 53.4 +/- SEM 15.1%, and a combined stone/sludge recurrence rate of 63.4 +/- 13.5%.

CONCLUSIONS

PCCL is moderately effective but, because of the frequency of complications and sludge/stone recurrence, is likely to have only a limited residual role in the era of laparoscopic cholecystectomy.

Deciding to buy expensive technology. The case of biliary lithotripsy

Acquiring expensive, new medical technology requires an evaluation of the efficacy and effectiveness, safety, profitability, feasibility, and risk of a project in the context of the hospital's social responsibility and institutional strategy. A case study of the decision to bring biliary lithotripsy to Strong Memorial Hospital illustrates how these criteria offer managers a coherent approach to difficult and consequential decisions about acquiring medical technology.

The efficacy of extracorporeal shock wave lithotripsy on single dense calcified gallstones according to computed tomography

The efficacy and complications of extracorporeal shock wave lithotripsy (ESWL) for single gallstones were compared between 15 patients with a CT-lucent stone and 18 patients with a dense calcified stone. In all of five patients with a stone smaller than 10 mm in diameter, complete or sufficient clearance was observed, regardless of calcification. However, in 28 patients with a stone larger than 11 mm in diameter, the rates of complete or sufficient clearance were lower in those with a dense calcified stone (64%) than in those with a computed tomography (CT) lucent stone (93%). There was no difference in the rate of complications between patients with a CT-lucent stone and those with a dense calcified stone. These results thus suggest that extracorporeal shock wave lithotripsy may be safely employed for patients with a single calcified gallstone.

Gallstone lithotripsy

Extracorporeal shock-wave lithotripsy (ESWL) has been applied to patients with gallstones since the mid-1980s. Lithotriptors differ by their means of shock-wave generation, the mechanisms by which they are coupled to the patient, and their imaging systems. Entry in most treatment protocols is limited to symptomatic patients with one to three radiolucent stones having a diameter of 30 mm or less and a functioning gallbladder according to oral cholecystography. Treatments are given on an out-patient basis using intravenous analgesia and include adjuvant bile acid therapy. Deaths have not been reported, and the incidence of serious complications, related to the presence of fragments in the biliary system, is low. The studies show that ESWL is a safe and effective treatment for patients with a single gallstone less than or equal to 20 mm in diameter, but the efficacy for larger single stones and multiple stones is poor. To date, the Food and Drug Administration has not approved lithotriptors for the treatment of gallstones in the United States.

Computed tomography after ESWL of gallbladder calculi

Computed tomography (CT) was performed on 88 patients before and after extracorporeal shock wave lithotripsy (ESWL) of gallstones to find the effects of ESWL on the gallbladder and surrounding liver tissue. Post-ESWL scans demonstrated a thickening of the gallbladder wall in 25 (28.4%) cases. In one patient an intrahepatic bilioma beside the gallbladder was seen 3 days after ESWL treatment. Hematoma of the gallbladder wall or the adjacent liver tissue was not seen, and neither a hydrops nor biliary-induced pancreatitis was observed. The authors conclude that while some patients undergoing ESWL will show some posttreatment abnormality on CT scans, the procedure is associated with a low frequency of serious gallbladder and liver trauma.

Gallbladder stones: shockwave therapy

Within the past 7 years, gallbladder lithotripsy by shockwaves has been proven to be a safe and effective non-invasive therapy for selected patients with gallstone disease. While regulatory decisions prevent shockwave therapy from being used more frequently in the USA, the number of patients treated in Europe and Asia is increasing constantly. At our institution, a relatively constant number of about 250 new patients per year have been treated since 1988 (Figure 4). About 20% of patients with gallstones are suitable for shockwave therapy according to present criteria. The rate of evacuation of all fragments is determined by the initial stone number and stone size, the success at stone fragmentation, adjuvant bile acid dissolution therapy, and gallbladder contractility. In contrast to laparoscopic cholecystectomy (Dubois et al, 1989; Perissat et al, 1989; Southern Surgeons Club, 1991), shockwave therapy does not require general anaesthesia. And in contrast to direct contact dissolution therapy of gallbladder stones using MTBE (Thistle et al, 1989), lithotripsy is non-invasive. In the majority of patients, complete fragment disappearance takes several months. Preliminary analyses of the cost-effectiveness of lithotripsy have revealed that lithotripsy, including retreatments and bile acid medication for recurrent stones, costs about as much as open cholecystectomy (Rothschild et al, 1990; Bass et al, 1991). The ideal patient for gallbladder lithotripsy has a single radiolucent stone < or = 20-25 mm in diameter in a functioning gallbladder (Figure 1). In patients with such stones, nearly all studies have confirmed a favourable outcome with rapid clearance of all fragments and a relatively low rate of stone recurrence. For carefully selected patients, extracorporeal shockwave lithotripsy is therefore an attractive non-invasive therapy.

Gallstones during octreotide therapy

Gallbladder stones (GBS) are found in up to 50% of patients receiving octreotide, but the reported prevalence of cholecystolithiasis in patients treated with octreotide is variable and little is known about gallstone incidence, composition, pathogenetic mechanisms, dissolvability, and primary prevention. Octreotide treatment apart, in industrialised societies most GBS are mixed in composition, cholesterol-rich (arbitrarily greater than 70% cholesterol by weight), radiolucent (70%), and, given a patent cystic duct (70%), dissolvable in bile rendered unsaturated in cholesterol by oral ursodeoxycholic (UDCA) +/- chenodeoxycholic (CDCA) acid treatment. They form when (1) GB bile becomes supersaturated with cholesterol (as the molar ratio of cholesterol to phospholipids in biliary vesicles approaches 1:1, the vesicles become unstable); (2) there is an imbalance between pro- and anti-nucleating factors, which favors cholesterol crystal precipitation; and (3) there is stasis within the GB as a result of altered motor function and/or excess mucus that traps the crystals. These changes may be associated with altered (4) biliary bile acid composition (more DCA and less CDCA than normal), and/or (5) phospholipid fatty acid composition (arachidonyl-rich lecithin acting as a substrate for mucosal prostaglandin synthesis which, in turn, may influence both gallbladder motility, and mucus glycoprotein synthesis and secretion). During octreotide treatment, meal-stimulated cholecystokinin (CCK) release is impaired leading to GB hypomotility, but little is known about the effects of octreotide on biliary cholesterol saturation, crystal nucleation time, mucus glycoprotein concentration, bile acid or phospholipid fatty acid composition. Most, but not all, reports suggest that the prevalence of GBS in octreotide-treated patients is considerably greater than that in age-, sex-, and weight-matched controls, but proof (by pre-treatment and on-treatment ultrasound) that the GBS were absent before, but developed during, therapy is not always available. Furthermore, there are few data on analysis of GBS composition in patients developing stones during treatment, although initial reports suggest that octreotide-associated GBS are also radiolucent, cholesterol-rich, and dissolve with oral bile acid treatment. Maximum GBS attenuation values, measured in Hounsfield Units (HU) by localized computerized tomography scanning of the GB, predict stone composition and dissolvability: GBS with scores of less than 100 HU are cholesterol-rich and dissolve well with oral bile acid treatment. However, preliminary results in 11 acromegalic patients treated with 200 to 600 micrograms octreotide/d for 29 to 68 months show that the HU scores range from 23 to 490 (mean +/- SEM, 116 +/- 41), suggesting that at least four of these 11 patients have non-cholesterol stones.(ABSTRACT TRUNCATED AT 400 WORDS)

Extracorporeal shockwave lithotripsy and litholytic therapy in cholelithiasis

Extracorporeal shockwave lithotripsy (ESWL) and litholytic therapy were used in 100 patients over a period of 16 months. ESWL was carried out with a Lithostar Plus and chenodeoxycholic acid was used as the lytic agent, given until 3 months after complete disappearance of stones. Within a period of 8-12 months, stones disappeared completely in 82 per cent of the patients who had a single stone less than or equal to 20 mm in diameter and in 50 per cent of those with a single stone greater than 20 mm in size or with multiple stones. Complications requiring surgery developed in five patients: three had acute cholecystitis and two developed acute pancreatitis. Of the patients in whom complete stone clearance was achieved, two of 11 followed up developed recurrence of stones 4 months after cessation of lytic therapy.

Treatment of symptomatic cholelithiasis in France. A decision analysis comparing cholecystectomy and biliary lithotripsy

To determine the potential role of extracorporeal shock wave lithotripsy (ESWL) in the treatment of symptomatic gallstone patients in France, a simulation model evaluated the health and economic effects of three different treatment strategies. Decision analysis of conventional cholecystectomy alone and either of two strategies using a combination of biliary lithotripsy and conventional cholecystectomy reveals that a strategy employing biliary ESWL results in a significant number of successfully treated patients, thus avoiding the risks and costs of abdominal surgery. Moreover, cost analysis shows that expanding the use of lithotripsy to all patients for whom the procedure is indicated increases the average cost per successfully treated patient, but, more importantly, decreases the overall costs incurred by the cohort. From a societal viewpoint, a policy using biliary ESWL in appropriate patients is superior to one of cholecystectomy alone, from both clinical and economic perspectives.

Gallbladder stones--dissolve, blast, or extract? Laparoscopic cholecystectomy versus 'the rest'

This article reviews selected aspects of the non-surgical/minimally invasive treatments of gallbladder stones (GBS) and discusses briefly the residual role of these treatments in the era of laparoscopic cholecystectomy. In patients with specific, gallstone-related symptoms who wish to retain their 'functioning' gallbladders, there are at least six different management options. They range from rapid but invasive to slow but safe: i) the rotary lithotrite; ii) percutaneous cholecystolithotomy; iii) percutaneous transhepatic or iv) endoscopic retrograde cannulation of the gallbladder followed by instillation (manual or pump-assisted) of contact solvents; v) extracorporeal shock-wave lithotripsy + adjuvant bile acids and; vi) oral bile acids alone. The recommended investigation sequence is i) ultrasound (to diagnose the presence of GBS), followed by ii) oral cholecystography (to assess cystic duct patency, gallbladder anatomy and GBS size, number, lucency, buoyancy, and contour), and iii) regional computed tomography scanning of the gallbladder (to predict stone composition and dissolvability and to plan routes of access to the gallbladder). The decision-making steps are i) choice of some form of active treatment versus no treatment (other than observation); ii) in those with specific symptoms and a patent cystic duct who opt for active treatment, to choose between removing versus retaining the gallbladder; and iii) in those who wish to retain their 'functioning' gallbladder, to offer and select the most appropriate of the alternative options. In conclusion, despite the excellence of laparoscopic cholecystectomy, there remains a place for the non-surgical/minimally invasive approaches in a carefully selected minority of symptomatic GBS patients. Although GBS may recur in approximately 50% of patients, the recurrent stones are often asymptomatic, can be detected 'early' by follow-up ultrasound, and are easily treated. Ultimately, the aim of gallstone research must be to prevent not only recurrent but also primary GBS formation, which would obviate the need for both medical and surgical treatment.

Lithotripsy versus cholecystectomy for management of gallstones. A decision analysis by Markov process

Extracorporeal shock-wave lithotripsy is a new treatment method that effectively distintegrates radiolucent gallstones and is associated with a low complication rate. Using the model of a Markov process for decision analysis, survival and costs under four possible strategies to treat gallstones were compared: expectant management with cholecystectomy (EC) or lithotripsy (EL) reserved for symptomatic gallstones; prophylactic cholecystectomy (PC) or lithotripsy (PL) for all gallstones. Life expectancy for the different strategies varies by few days. Only if high annual rates of pain and complication occurred in subjects with silent gallstones would both prophylactic procedures marginally increase life expectancy. Prophylactic cholecystectomy then would be more cost-effective than prophylactic lithotripsy. Expectant strategies remain much cheaper than prophylactic management over a broad range of probability values and procedural costs. Expectant use of lithotripsy costs less than cholecystectomy. A low success rate of lithotripsy would raise the direct costs of lithotripsy above those of cholecystectomy but leave total costs of both strategies in the same order of magnitude. Lithotripsy appears to be a feasible alternative to treat symptomatic but not asymptomatic gallstones.

Human gallbladder morphology after gallstone dissolution with methyl tert-butyl ether

The effects of methyl tert-butyl ether exposure on the human gallbladder in five patients who were treated for gallstones by contact dissolution is described. Two patients underwent cholecystectomy within 1 week of methyl tert-butyl ether treatment, one patient 2 weeks after, another 10 weeks after, and one 12 weeks after. Indications for cholecystectomy were bilirubinate stones (resistant to methyl tert-butyl ether), catheter dislodgement, bile leakage, and gallstone recurrence (2 patients). Gallstones were dissolved completely in three patients, there was approximately 50% stone reduction in one patient, and no dissolution occurred in the fifth patient. Each gallbladder was examined grossly and histologically. Electron microscopic evaluation was performed in one cases. Typical inflammatory findings of chronic cholecystitis were observed in each gallbladder and were most conspicuous in the submucosa; the mucosal and serosal surfaces were intact. Mild acute inflammatory changes were noted in the submucosa in the two patients with the shortest interval between methyl tert-butyl ether administration and cholecystectomy. There were no ulcerations in the mucosa and no unusual wall thickening or fibrosis in any patient. These observations support the safety of methyl tert-butyl ether perfusion in the human gallbladder; the mild acute changes may be a transient and reversible phenomenon.

The economic burden of gallstone lithotripsy. Will cost determine its fate?

Gallstone lithotripsy (LITHO) was performed on 52 patients who underwent 107 procedures. Two hundred sixty-seven gallstone patients were screened and 215 (81%) were excluded. Excessive stone burden and nonvisualization by oral cholecystogram (OCG) were the most common reasons for exclusion. The hospital course of 100 excluded patients who later underwent elective cholecystectomy was evaluated for length of hospital stay (2.3 days) and total cost of treatment ($3685.00). Successful fragmentation to less than 5 mm was achieved in 43 LITHO patients (83%). Five LITHO patients (10%) required conversion to operative management. Complications of LITHO included acute cholecystitis (1 of 52 patients) and biliary colic (17 of 52 patients, or 33%). Multiple procedures in one patient were common. Costs for LITHO were calculated in two ways: first the individual cost for each of the 52 candidates; second the cost for successful LITHO was calculated by excluding five patients who required operation as well as five patients (10%) who are predicted failures of LITHO. Including the preoperative evaluation, treatment, recovery room, and follow-up, the individual LITHO cost for 52 patients was $8275.00. If the same total expenditure is calculated after excluding patients who required operation and those predicted to fail, the cost per 'successful' LITHO procedure was $10,245. The cost of 1 year of bile acid therapy is $1949.00 or $2413.00 per 'successful' procedure. Follow-up costs were $1232.00 per patient or $1525.00 per 'successful' procedure. The added LITHO cost incurred by screening eventual noncandidates was $904.00 per successful procedure. The sum of these individual costs was $15,087.00 per success, as compared to $3685.00 for cholecystectomy. No allowance was made for cost of stone recurrence. Lithotripsy costs appear to be sufficiently high to render the procedure unlikely to emerge as the treatment of choice.

New trends in gallstone management

Many new therapies for the management of gallstone disease have been pioneered in the past decade. The object of this review is to equip the surgeon with the answers to all of the questions a patient will ask about gallstone therapy; the review is therefore didactic as well as comprehensive.

Gallstone clearance: a randomized study of extracorporeal shock wave lithotripsy and chemical dissolution

Following extracorporeal shock wave lithotripsy it is not known whether gallstone fragments are cleared from the gallbladder without the use of oral dissolution therapy. To assess the efficacy of lithotripsy and dissolution therapy, alone or in combination, 35 patients were randomized to one of three treatment groups: lithotripsy alone, dissolution therapy alone or combined lithotripsy and dissolution therapy. All patients had symptomatic gallstones, functioning gallbladders and comparable stone profiles. Lithotripsy was administered using a piezoelectric lithotripter. Dissolution therapy consisted of combined bile acid and terpene. Clearance was assessed at 6 months using ultrasound and oral cholecystography. Patients with less than 50 per cent stone clearance at the end of 6 months were considered failures. The number of patients with total or partial clearance in the combined group (7/10) was significantly greater than those in the lithotripsy alone group (0/10, P less than 0.002). Gallstone clearance following lithotripsy appears to be dependent upon dissolution therapy.

The effect of ursodiol on the efficacy and safety of extracorporeal shock-wave lithotripsy of gallstones. The Dornier National Biliary Lithotripsy Study

BACKGROUND

In the treatment of gallstones with extracorporeal shock-wave lithotripsy, the bile acid ursodiol is administered to dissolve the gallstone fragments. We designed our study to determine the value of administering this agent.

METHODS

At 10 centers, 600 symptomatic patients with three or fewer radiolucent gallstones 5 to 30 mm in diameter, as visualized by oral cholecystography, were randomly assigned to receive ursodiol or placebo for six months, starting one week before lithotripsy.

RESULTS

The stones were fragmented in 97 percent of all patients, and the fragments were less than or equal to 5 mm in diameter in 46.8 percent. On the basis of an intention-to-treat analysis of all 600 patients, 21 percent receiving ursodiol and 9 percent receiving placebo (P less than 0.0001) had gallbladders that were free of stones after six months. Among those with completely radiolucent solitary stones less than 20 mm in diameter, 35 percent of the patients receiving ursodiol and 18 percent of those receiving placebo (P less than 0.001) were free of stones after six months. Biliary pain, usually mild, occurred in 73 percent of all patients but in only 13 percent of those who were free of stones after three and six months (P less than 0.01). There were few adverse events. Only diarrhea occurred with a significantly different frequency in the two groups: 32.6 percent were affected in the ursodiol group, as compared with 24.7 percent in the placebo group (P less than 0.04). Severe biliary pain occurred in 1.5 percent of all patients, acute cholecystitis in 1.0 percent, and acute pancreatitis in 1.5 percent; endoscopic sphincterotomy was performed in 0.5 percent, and cholecystectomy in 2.5 percent.

CONCLUSIONS

Extracorporeal shock-wave lithotripsy with ursodiol was more effective than lithotripsy alone for the treatment of symptomatic gallstones, and equally safe. Treatment was more effective for solitary than multiple stones, radiolucent than slightly calcified stones, and smaller than larger stones.

Percutaneous endoscopic treatment of cholelithiasis

Surgical management of gallstones was first performed successfully in 1878. Over the past decade, several new treatment alternatives have evolved that challenge the supremacy of traditional surgical cholecystectomy. Two endoscopic alternatives, e.g., percutaneous cholecystolithotomy (PCCL) and laparoscopic cholecystectomy (LC) are the latest additions to the growing armamentarium. Our initial experience with PCCL and LC as compared with our traditional cholecystectomy experience shows a 57% reduction in hospital days, a 58% reduction in postoperative analgesic dose, and 50% or more reduction in disabling convalescence in favor of the endoscopic alternatives. A review of the efficacy and morbidity of traditional surgery, peroral drug chemolysis (PDC), shockwave lithotripsy plus PDC, and percutaneous transhepatic lavage with methyl terbutyl ether suggests that the endoscopic alternatives are less morbid than traditional surgery and more efficacious and perhaps less morbid than other non-invasive or minimally invasive alternatives. Both original data and a literature review are presented.

Nonsurgical treatment of cholelithiasis. An analysis of clinical opportunity

This article examines the potential impact of recently developed nonsurgical treatments for gallstones on patient care and resource utilization. Using epidemiological and efficacy data from the literature and current patient selection criteria, the authors evaluate UDCA, extracorporeal shock-wave lithotripsy, and direct instillation of methyltertbutyl ether in terms of short-term clinical results, health policy, and economic implications.

Biliary extracorporeal shockwave lithotripsy

Biliary extracorporeal lithotripsy has been considered one of the alternatives to surgery for the treatment of gallstones in the bile ducts and in the gallbladder. Although this technique can fragment almost all gallstones, the clinical effectiveness of this new treatment modality must be measured by successful elimination of all fragments. Some physical principles, stone targeting, patient protocol, complications, and clinical results are presented.

Review article: bile acid therapy

Over the past 3 years there has been a renewed interest in bile acid therapy not only because of the promising results obtained by combining this therapy with extracorporeal shock-wave lithotripsy for rapid gallstone dissolution, but also because of its novel use as a treatment for primary biliary cirrhosis. This article reviews the use of bile acids for both these indications.

Non-operative management of gallstones--a preliminary review

We describe our initial experience with extracorporeal shock-wave lithotripsy, direct solvent dissolution with methyl tert-butyl ether and mechanical extraction, in 17 symptomatic patients without significant gall-bladder wall disease using existing criteria for selection. Extracorporeal shock-wave lithotripsy and mechanical extraction are promising techniques. Methyl tert-butyl ether therapy has been fraught with difficulty.

Extracorporeal shockwave lithotripsy of gallstones. Possibilities and limitations

Recently extracorporeal shockwave lithotripsy (ESWL) has been introduced as a nonoperative treatment for gallstone disease. Except for lung damage, no significant adverse effects of ESWL of gallbladder stones have been observed in animals. In clinical use ESWL of gallbladder stones is now confined to 15% to 30% of symptomatic patients. To achieve complete stone clearance, ESWL of gallbladder stones must be supplemented by an adjuvant therapy. ESWL of bile duct stones is highly effective and can be considered in patients in whom primary endoscopic or surgical stone removal fails. Second generation lithotriptors allow anesthesia-free (outpatient) treatments, but the clinical experience with most of these ESWL devices is still limited. The likelihood of gallbladder stone recurrence is a major disadvantage of ESWL treatment, which raises the issue of cost-effectiveness. ESWL for cholelithiasis is a promising treatment modality with good short-term and unknown long-term results.

Principles of biliary extracorporeal lithotripsy. Technical considerations and clinical implications

After recent reports of the successful use of extracorporeal shock-wave lithotripsy for the treatment of gallstone disease, at least 10 different manufacturers have developed lithotripsy systems and initiated clinical trials in the United States. The three major types of lithotripters, classified by the method used to generate shock waves, are the spark-gap, piezoelectric, and electromagnetic systems. Although each type of system generates shock waves by different methods, all currently available systems appear to be able to fragment gallstones. However, there does not appear to be any system that has demonstrated clear clinical superiority in terms of either efficacy or safety. Additional information, both clinical and experimental, is needed before it can be determined if the type of shock-wave generator has a significant effect on outcome. Clearly more than the physical principles of shock-wave lithotripters must be evaluated.

Soft-tissue effects of biliary extracorporeal shockwave lithotripsy in swine

This study investigates the soft-tissue effects of biliary extracorporeal shockwave lithotripsy (BESWL) using a recently developed lithotripter, which consists of an electromagnetic shockwave generator and an integrated ultrasonic targeting system. Sixteen swine, evenly divided into four groups, underwent BESWL. One group had one BESWL session targeted on the gallbladder and another group had two BESWL sessions targeted on the gallbladder. The third group had one BESWL session targeted on implanted gallbladder stones and the fourth group had one BESWL session targeted on the region of the common bile duct (CBD). Half of each group were sacrificed on the day of lithotripsy and half 1 week later. Post-mortem examinations were performed. Each implanted gallstone had fragmented. There were no findings attributable to BESWL in 11 animals. Three animals had pulmonary haemorrhagic spots (the largest was 10 mm in diameter) and one had a submucosal CBD petechia; these findings were attributable to BESWL. In two animals, microscopic haemorrhage associated with bronchopneumonia (usually present in our pig population) was more prominent than usual. This was possibly attributable to BESWL. The swine's deep posterior costophrenic sulcus makes it difficult to avoid the lung base during BESWL in swine. We conclude that this BESWL device can fragment gallstones without causing clinically significant soft-tissue damage.

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.

Short-term effects of extracorporeal shock wave lithotripsy on the human gallbladder

Extracorporeal shock wave lithotripsy (ESWL), whereby shock wave energy is focused upon gallstones causing their disintegration into fragments sufficiently small to be passed via the biliary system, offers a promising non-invasive alternative to surgery for gallstone disease. The tissue effects in humans of ESWL are poorly characterized and no systematic study of the tissue effects of ESWL by piezoelectrically generated shock waves has been published. Sixteen patients for elective cholecystectomy were therefore subjected to ESWL before surgery and detailed histology of the gall-bladders (including scanning electron microscopy of the mucosa) was compared with that from 20 age/sex-matched control cases. The gall-bladders treated by ESWL, in addition to showing the histological changes associated with chronic cholecystitis, showed serosal vasodilatation, mural oedema, and serosal and mucosal petechial haemorrhages focally over the entire surface. Between 10 and 90 per cent epithelial denudation was observed, but all cases showed surviving columnar epithelial cells in the crypts. No case showed vascular thrombosis, tissue necrosis, or acute inflammation. These tissue effects are likely to be reversible and unlikely to present a risk of perforation, although the long-term clinicopathological effects await investigation.

Review article: dissolution of gallstones in the biliary tree

There are a variety of methods for dissolving gallstones in the biliary tree, which include oral therapy and direct contact dissolution. Cholesterol gallstones are most amenable to dissolution. Developments in non-operative physical methods to remove gallstones (particularly endoscopic papillotomy and extracorporeal shock-wave lithotripsy have diminished the use of chemical dissolution. However, in selected patients, there remains a place for chemical dissolution, but often in conjunction with the physical techniques.

Electromagnetically generated extracorporeal shock waves for gallstone lithotripsy: in vitro experiments and clinical relevance

First generation shock wave sources have been proved to disintegrate gallstones effectively, but they require the immersion of the patient's body in a tank of water. A recently developed second generation shock wave source (Siemens-Lithostar, Erlangen, FRG) generates shock waves electromagnetically. It presents several novel features. In particular the waterbath can be omitted and due to lower shock wave pressure general anaesthesia is not required. In vitro studies showed that 36 out of 38 gallstones (11-30 mm in diameter) could be disintegrated. Two concrements resisting lithotripsy were pure white cholesterol stones. Independent of shape, size, and composition (cholesterol or pigment) the maximum diameter of remaining fragments after lithotripsy was between 1 and 8 mm. For sufficient disintegration precise focusing (+/- 1 cm) of the stones and maximum power of the shock wave generator were required.