Efficacy and safety of a combination of chenodeoxycholic acid and ursodeoxycholic acid for gallstone dissolution: a comparison with ursodeoxycholic acid alone

Protective effect of Glechoma hederacea extract against gallstone formation in rodent models

Background

Our current study aimed to evaluate the effect of an Glechoma hederacea extract (Hitrechol®) in normal rats and gallstone diseased mice to explore its underlying mechanisms. Normal rats and C57BL/6 mice with/without cholesterol gallstone were used in this study.

Methods

To monitor the effect of Hitrechol® on bile secretion, bile flow rates at 15 min interval until 2 h post-dosing in normal rats treated with vehicle and Hitrechol® were compared using multiple t-test with a p < 0.05 considered as statistically significant different. To further evaluate the effect of Hitrechol® against the development of gallstone in lithogenic diet treated mice, mice were treated with vehicle or Hitrechol® (QD-once daily or TID-three times daily) for 3 weeks followed by comparing the levels of bile composition among the treatment groups. In addition, the anti-oxidative biomarkers in liver and anti-inflammatory biomarkers in serum were detected and compared among all the treatment groups to evaluate the hepato-protective effect of Hitrechol®. The obtained levels of biomarkers and bile composition were compared among different treatment groups using one-way ANOVA tests followed by Tukey’s multiple comparisons with p < 0.05 considered as statistically significant.

Results

Despite no significant impact on the bile flow rate, Hitrechol® TID treatment dramatically decreased size and amount of gallstone crystals and total cholesterol level (p < 0.05), as well as total bile acid (p < 0.05) and several types of bile acid (p < 0.05) levels in gallstone disease model mice. Hitrechol® TID treatment could significantly decrease the frequencies of hepatocyte necrosis and lipid aggregation notably as well as increase the antioxidant enzyme level (p < 0.05) in the liver.

Conclusions

Our findings for the first time demonstrated the beneficial effect of Hitrechol® against gallstone via its litholytic, liver-protective and antioxidant activities.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12906-021-03368-1.

Incident Gallstones During Somatostatin Analog Treatment are Associated with Acute Biliary Complications Especially After Discontinuation

INTRODUCTION

Gallstones are a known adverse effect of somatostatin analogs, but the exact incidence and clinical implications are unknown.

OBJECTIVES

The aim of this study was to investigate the incidence of gallstones on imaging and related complications in unbiased trial data.

METHODS

Data from the DIPAK 1 trial, in which 305 polycystic kidney disease patients were randomized to standard of care (SoC) or lanreotide for 120 weeks, were used. Magnetic resonance imaging (MRI) was performed at baseline and end of treatment and was assessed for the presence, number, and size of gallstones. For all patients who had gallstones at the end of the trial, we obtained follow-up after the trial.

RESULTS

Of 249 patients with data available, 11 patients randomized to lanreotide and four randomized to SoC had gallstones at baseline. During the study, new gallstones were formed in 19/124 patients using lanreotide (15%) and 1/125 patients receiving SoC (1%). The odds ratio for gallstone formation with lanreotide use was 25.9 (95% confidence interval 3.37-198.8; p < 0.001). Gallstones during lanreotide treatment were multiple (> 20 stones in 69% of patients) and small (≤ 3 mm in 63% of patients). Of the 19 patients with incident gallstones during lanreotide treatment, 9 experienced gallstone-associated complications, 8 of whom experienced gallstone-associated complications after discontinuation of treatment (median time after discontinuation 2.5 years). In patients with gallstones at baseline and in patients receiving SoC, no complications occurred.

CONCLUSIONS

Treatment with a somatostatin analog leads to the formation of multiple, small gallstones that are associated with severe complications, especially after discontinuation of therapy.

CLINICAL TRIAL REGISTRY WEBSITE AND TRIAL NUMBER

ClinicalTrials.gov ( https://clinicaltrials.gov ); NCT01616927.

[Management of Gallstone]

Gallstones are one of the most common diseases worldwide. Recently, the incidence of gallstones has increased and the pattern of gallstones has changed in Korea. Laparoscopic cholecystectomy is the standard treatment for symptomatic gallstones. Expectant management is considered the most appropriate choice in patients with asymptomatic gallstones. The dissolution of cholesterol gallstones by oral bile acid, such as ursodeoxycholic acid, can be considered in selected patients with gallstones. Although the advent of laparoscopic cholecystectomy has moved interest away from the pharmacologic treatment of gallstones, several promising agents related to various mechanisms are under investigation.

Latest development in the synthesis of ursodeoxycholic acid (UDCA): a critical review

Ursodeoxycholic acid (UDCA) is a pharmaceutical ingredient widely used in clinics. As bile acid it solubilizes cholesterol gallstones and improves the liver function in case of cholestatic diseases. UDCA can be obtained from cholic acid (CA), which is the most abundant and least expensive bile acid available. The now available chemical routes for the obtainment of UDCA yield about 30% of final product. For these syntheses several protection and deprotection steps requiring toxic and dangerous reagents have to be performed, leading to the production of a series of waste products. In many cases the cholic acid itself first needs to be prepared from its taurinated and glycilated derivatives in the bile, thus adding to the complexity and multitude of steps involved of the synthetic process. For these reasons, several studies have been performed towards the development of microbial transformations or chemoenzymatic procedures for the synthesis of UDCA starting from CA or chenodeoxycholic acid (CDCA). This promising approach led several research groups to focus their attention on the development of biotransformations with non-pathogenic, easy-to-manage microorganisms, and their enzymes. In particular, the enzymatic reactions involved are selective hydrolysis, epimerization of the hydroxy functions (by oxidation and subsequent reduction) and the specific hydroxylation and dehydroxylation of suitable positions in the steroid rings. In this minireview, we critically analyze the state of the art of the production of UDCA by several chemical, chemoenzymatic and enzymatic routes reported, highlighting the bottlenecks of each production step. Particular attention is placed on the precursors availability as well as the substrate loading in the process. Potential new routes and recent developments are discussed, in particular on the employment of flow-reactors. The latter technology allows to develop processes with shorter reaction times and lower costs for the chemical and enzymatic reactions involved.

Evidence-based clinical practice guidelines for cholelithiasis 2016

Cholelithiasis is one of the commonest diseases in gastroenterology. Remarkable improvements in therapeutic modalities for cholelithiasis and its complications are evident. The Japanese Society of Gastroenterology has revised the evidence-based clinical practice guidelines for cholelithiasis. Forty-three clinical questions, for four categories-epidemiology and pathogenesis, diagnosis, treatments, and prognosis and complications-were selected, and a literature search was performed for the clinical questions with use of the MEDLINE, Cochrane, and Igaku Chuo Zasshi databases for the period between 1983 and June 2012. The guidelines were developed with use of the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system. This article preferentially describes the clinical management of cholelithiasis and its complications. Following description of the diagnosis performed stepwise through imaging modalities, treatments of cholecystolithiasis, choledocholithiasis, and hepatolithiasis are introduced along with a flowchart. Since there have been remarkable improvements in endoscopic treatments and surgical techniques, the guidelines ensure flexibility in choices according to the actual clinical environment. The revised clinical practice guidelines are appropriate for use by clinicians in their daily practice.

Efficacy of Magnesium Trihydrate of Ursodeoxycholic Acid and Chenodeoxycholic Acid for Gallstone Dissolution: A Prospective Multicenter Trial

Background/Aims

Cholecystectomy is necessary for the treatment of symptomatic or complicated gallbladder (GB) stones, but oral litholysis with bile acids is an attractive alternative therapeutic option for asymptomatic or mildly symptomatic patients. This study was conducted to evaluate the efficacy of magnesium trihydrate of ursodeoxycholic acid (UDCA) and chenodeoxycholic acid (CDCA) on gallstone dissolution and to investigate improvements in gallstone-related symptoms.

Methods

A prospective, multicenter, phase 4 clinical study to determine the efficacy of orally administered magnesium trihydrate of UDCA and CDCA was performed from January 2011 to June 2013. The inclusion criteria were GB stone diameter ≤15 mm, GB ejection fraction ≥50%, radiolucency on plain X-ray, and asymptomatic/mildly symptomatic patients. The patients were prescribed one capsule of magnesium trihydrate of UDCA and CDCA at breakfast and two capsules at bedtime for 6 months. The dissolution rate, response rate, and change in symptom score were evaluated.

Results

A total of 237 subjects were enrolled, and 195 subjects completed the treatment. The dissolution rate was 45.1% and the response rate was 47.2% (92/195) after 6 months of administration of magnesium trihydrate of UDCA and CDCA. Only the stone diameter was significantly associated with the response rate. Both the symptom score and the number of patients with symptoms significantly decreased regardless of stone dissolution. Adverse events necessitating discontinuation of the drug, surgery, or endoscopic management occurred in 2.5% (6/237) of patients.

Conclusions

Magnesium trihydrate of UDCA and CDCA is a well-tolerated bile acid that showed similar efficacy for gallstone dissolution and improvement of gallstone-related symptoms as that shown in previous studies.

Comparison on Response and Dissolution Rates Between Ursodeoxycholic Acid Alone or in Combination With Chenodeoxycholic Acid for Gallstone Dissolution According to Stone Density on CT Scan: Strobe Compliant Observation Study

Medical dissolution of gallstone is usually performed on radiolucent gallstones in a functioning gallbladder. However, absence of visible gallstone on plain abdominal x-ray does not always preclude calcification. This study aims to compare the response and dissolution rates between ursodeoxycholic acid (UDCA) alone or in combination with chenodeoxycholic acid (CDCA) according to stone density on computed tomography (CT) scan. A total of 126 patients underwent dissolution therapy with either UDCA alone or combination of CDCA and UDCA (CNU) from December 2010 to March 2014 at Korea University Ansan Hospital. In the end, 81 patients (CNU group = 44, UDCA group = 37) completed dissolution therapy for 6 months. Dissolution rate (percentage reduction in the gallstone volume) and response to therapy (complete dissolution or partial dissolution defined as reduction in stone volume of >50%) were compared between the 2 groups. Dissolution and response rates of sludge was also compared between the 2 groups. The overall response rate was 50.6% (CNU group 43.2% vs UDCA group 59.5%, P = 0.14), and the overall dissolution rate was 48.34% (CNU group 41.5% vs UDCA group 56.5%, P = 0.13). When analyzed according to stone density, response rate was 33.3%, 87.1%, 30.0%, and 6.2% for hypodense, isodense, hyperdense, and calcified stones, respectively. Response rate (85.7% vs 88.2%, P = 0.83) and dissolution rate (81.01% vs 85.38%, P = 0.17) of isodense stones were similar between CNU and UDCA group. When only sludge was considered, the overall response rate was 87.5% (CNU group 71.4% vs UDCA group 94.1%, P = 0.19), and the overall dissolution rate was 85.42% (CNU group 67.9% vs UDCA group 92.7%, P = 0.23). Patients with isodense gallstones and sludge showed much better response to dissolution therapy with CNU and UDCA showing comparable efficacy. Therefore, CT scan should be performed before medication therapy if stone dissolution is intended.

Enzymatic routes for the synthesis of ursodeoxycholic acid

Ursodeoxycholic acid, a secondary bile acid, is used as a drug for the treatment of various liver diseases, the optimal dose comprises the range of 8-10mg/kg/day. For industrial syntheses, the structural complexity of this bile acid requires the use of an appropriate starting material as well as the application of regio- and enantio-selective enzymes for its derivatization. Most strategies for the synthesis start from cholic acid or chenodeoxycholic acid. The latter requires the conversion of the hydroxyl group at C-7 from α- into β-position in order to obtain ursodeoxycholic acid. Cholic acid on the other hand does not only require the same epimerization reaction at C-7 but the removal of the hydroxyl group at C-12 as well. There are several bacterial regio- and enantio-selective hydroxysteroid dehydrogenases (HSDHs) to carry out the desired reactions, for example 7α-HSDHs from strains of Clostridium, Bacteroides or Xanthomonas, 7β-HSDHs from Clostridium, Collinsella, or Ruminococcus, or 12α-HSDH from Clostridium or from Eggerthella. However, all these bioconversion reactions need additional steps for the regeneration of the coenzymes. Selected multi-step reaction systems for the synthesis of ursodeoxycholic acid are presented in this review.

Steroid degradation in Comamonas testosteroni

Steroid degradation by Comamonas testosteroni and Nocardia restrictus have been intensively studied for the purpose of obtaining materials for steroid drug synthesis. C. testosteroni degrades side chains and converts single/double bonds of certain steroid compounds to produce androsta-1,4-diene 3,17-dione or the derivative. Following 9α-hydroxylation leads to aromatization of the A-ring accompanied by cleavage of the B-ring, and aromatized A-ring is hydroxylated at C-4 position, cleaved at Δ4 by meta-cleavage, and divided into 2-hydroxyhexa-2,4-dienoic acid (A-ring) and 9,17-dioxo-1,2,3,4,10,19-hexanorandrostan-5-oic acid (B,C,D-ring) by hydrolysis. Reactions and the genes involved in the cleavage and the following degradation of the A-ring are similar to those for bacterial biphenyl degradation, and 9,17-dioxo-1,2,3,4,10,19-hexanorandrostan-5-oic acid degradation is suggested to be mainly β-oxidation. Genes involved in A-ring aromatization and degradation form a gene cluster, and the genes involved in β-oxidation of 9,17-dioxo-1,2,3,4,10,19-hexanorandrostan-5-oic acid also comprise a large cluster of more than 10 genes. The DNA region between these two main steroid degradation gene clusters contain 3α-hydroxysteroid dehydrogenase gene, Δ5,3-ketosteroid isomerase gene, genes for inversion of an α-oriented-hydroxyl group to a β-oriented-hydroxyl group at C-12 position of cholic acid, and genes possibly involved in the degradation of a side chain at C-17 position of cholic acid, indicating this DNA region of more than 100kb to be a steroid degradation gene hot spot of C. testosteroni. Article from a special issue on steroids and microorganisms.

New dental composites containing multimethacrylate derivatives of bile acids: a comparative study with commercial monomers

We have prepared multifunctional methacrylate derivatives of bile acids as cross-linkable monomers for use in dental composites. By modifying the chemical structure of the monomers, we were able to vary the viscosity, hydrophobicity, and reactivity and have studied the effect of these parameters on the conversion of the monomers, the shrinkage during polymerization, and the mechanical properties of the resulting polymers and composites. Materials containing these new monomers generally had physical, thermal, and mechanical properties comparable to those containing the commonly used dental monomers BisGMA or UDMA and had lower polymerization shrinkage. The multimethacrylate derivatives of cholic acid, which are known to be less cytotoxic than BisGMA and UDMA, are shown to be promising materials for dental applications.

Estimation of cholesterol solubilization by a mixed micelle binding model in aqueous tauroursodeoxycholate:lecithin:cholesterol solutions

In order to interpret the clinical efficacy of conjugated ursodeoxycholate (UDC) in cholesterol (Ch) gallstone patients, the Ch solubilization in mixed micelles in 40:40:32 mM tauroursodeoxycholate (TUDC):taurochenodeoxycholate (TCDC):lecithin (L) and 80:32 mM TUDC:L systems was estimated by using a model of Ch binding to mixed micelles. The Ch solubilization limit in mixed TUDC:L micelles was found to be higher than that in mixed TUDC:TCDC:L micelles. In the 80:32 mM TUDC:L system, the dissolution of the Ch pellet decreased after vesicles (liposomes) formed on the surface of the Ch pellet whereas the dissolution of microcrystalline Ch was rapid before and after vesicle formation in the solution, indicating that the total surface area of solid Ch exposed to the solution may be another important factor in inducing the dissolution of Ch gallstones. These phenomena suggest that although vesicles, occasionally formed in the bile of patients under the therapy of conjugated UDC, make a contribution to the solubilization of Ch gallstones, the model of Ch binding to mixed TUDC:L micelles can be used to estimate Ch solubility in TUDC:L system.

Megalin and cubilin expression in gallbladder epithelium and regulation by bile acids

Cholesterol crystal formation in the gallbladder is a key step in gallstone pathogenesis. Gallbladder epithelial cells might prevent luminal gallstone formation through a poorly understood cholesterol absorption process. Genetic studies in mice have highlighted potential gallstone susceptibility alleles, Lith genes, which include the gene for megalin. Megalin, in conjunction with the large peripheral membrane protein cubilin, mediates the endocytosis of numerous ligands, including HDL/apolipoprotein A-I (apoA-I). Although the bile contains apoA-I and several cholesterol-binding megalin ligands, the expression of megalin and cubilin in the gallbladder has not been investigated. Here, we show that both proteins are expressed by human and mouse gallbladder epithelia. In vitro studies using a megalin-expressing cell line showed that lithocholic acid strongly inhibits and cholic and chenodeoxycholic acids increase megalin expression. The effects of bile acids (BAs) were also demonstrated in vivo, analyzing gallbladder levels of megalin and cubilin from mice fed with different BAs. The BA effects could be mediated by the farnesoid X receptor, expressed in the gallbladder. Megalin protein was also strongly increased after feeding a lithogenic diet. These results indicate a physiological role for megalin and cubilin in the gallbladder and provide support for a role for megalin in gallstone pathogenesis.

[Biliary lithiasis in childhood: therapeutic approaches]

Until recently, biliary lithiasis was considered infrequent in childhood. According to their composition, gallstones can be classified into cholesterol stones and pigment stones. The latter are mainly composed of calcium salts of unconjugated bilirubin and are divided into hard black and soft brown stones. In children, up to 75 % of gallstones are pigment stones. Their etiology is often unknown. Biliary lithiasis in children differs from that in adults and there is very little scientific evidence on the most suitable therapeutic procedures. Symptom-free stones usually have a benign course and do not require medical or surgical treatment. Symptoms are often nonspecific and include dyspepsia and chronic abdominal pain. These symptoms are an indication for ultrasonographic scan to rule out the presence of gallstones. Cholecystectomy is the definitive treatment for gallstones but is not always indicated. Medical treatment with ursodeoxycholic acid is indicated in oligosymptomatic and asymptomatic lithiasis with transparent, soft, cholesterol-rich stones and a functional bladder and in patients with a high surgical risk.

Cholelithiasis in pediatric organ transplantation: detection and management

The real incidence and the underlying causes of cholelithiasis in pediatric solid organ recipients is probably not exactly known. In addition to well-established risk factors for cholelithiasis, children after heart, kidney, or liver transplantation may develop gallstones due to drug therapy, sepsis, parenteral nutrition, or surgical complications. For pediatric patients, data are very limited and heterogeneous. However, the incidence in pediatric heart recipients seems to be substantially higher compared with kidney or liver graft recipients. In this review article the present data are discussed focusing on incidence, detection, and management of cholelithiasis in pediatric organ transplantation. In general, surgery is the therapy of choice in symptomatic patients; however, the pharmacological profile of ursodeoxycholic acid and the first results on its clinical impact are promising. The value of prophylactic therapy with ursodeoxycholic acid must be determined in further studies.

The therapeutic effects of ursodeoxycholic acid as an anti-apoptotic agent

The dihydroxy bile acid, ursodeoxycholic acid (UDCA), has been in widespread clinical use in the Western world since the mid 1980s, when it was initially used for gallstone dissolution [1,2] and subsequently for the treatment of chronic cholestatic liver diseases [3,4]. Many clinical trials of UDCA in a variety of cholestatic disorders established biochemical and clinical improvements, and most importantly showed a significant prolongation of transplant-free survival after four years of treatment with UDCA in patients with primary biliary cirrhosis [5]. Despite its clinical efficacy, the precise mechanism(s) by which UDCA improves liver function during cholestasis is still a matter of debate [6]. It was initially considered that the choleretic effect of UDCA, coupled with its ability to cause a marked shift in the composition of the bile acid pool towards hydrophilicity, accounted for its mechanism of action. In recent years, however, it has become evident that UDCA and its conjugated derivatives are capable of exerting direct effects at the cellular, subcellular, and molecular levels by stabilising cell membranes, affecting signal transduction pathways, and regulating immune responses. In addition, we have shown that UDCA plays a unique role in modulating the apoptotic threshold in both hepatic and non-hepatic cells [7-10]. The purpose of this article is to examine the mechanism(s) by which UDCA prevents apoptotic cell death associated with cholestasis. In addition, we will also review a potentially novel and, heretofore, unrecognised role of UDCA as a therapeutic agent in the treatment of non-liver diseases associated with increased levels of apoptosis as a pathogenesis of the disorder.

Ursodeoxycholic acid alone or with chenodeoxycholic acid for dissolution of cholesterol gallstones: a randomized multicentre trial. The British-Italian Gallstone Study group

BACKGROUND

Combination therapy using ursodeoxycholic acid plus chenodeoxycholic acid has been advocated for dissolution of cholesterol gallstones because the two bile acids have complementary effects on biliary lipid metabolism and cholesterol solubilization.

AIM

To compare the clinical efficacy of combination therapy with ursodeoxycholic acid monotherapy.

PATIENTS AND METHODS

A total of 154 symptomatic patients with radiolucent stones (< or = 15 mm) in functioning gallbladders were enrolled from six centres in England and Italy. They were randomized to either a combination of chenodeoxycholic acid plus ursodeoxycholic acid (5 mg.day/kg each) or to ursodeoxycholic acid alone (10 mg.day/kg). Dissolution was assessed by 6-monthly oral cholecystography and ultrasonography for up to 24 months.

RESULTS

Both regimens reduced the frequency of biliary pain and there was no significant difference between them in terms of side-effects or dropout rate. Complete gallstone dissolution on an intention-to-treat basis was similar at all time intervals. At 24 months this was 28% with ursodeoxycholic acid alone and 30% with combination therapy. The mean dissolution rates at 6 and 12 months were 47% and 59% with ursodeoxycholic acid, and 44% and 59% with combination therapy, respectively.

CONCLUSION

There is no substantial difference in the efficacy of combined ursodeoxycholic acid and chenodeoxycholic acid and that of ursodeoxycholic acid alone in terms of gallstone dissolution rate, complete gallstone dissolution, or relief of biliary pain.

Nonsurgical management of gallstone disease

Cholelithiasis is a common disease in the United States associated with significant morbidity. Surgical treatment with cholecystectomy has been increasing with a significant cost to the health care system. Surgical management is not without risk. Cholecystectomy has also been associated with a significant morbidity and mortality in elderly patients. Cholecystectomies are often performed unnecessarily in gallstone patients for nonspecific symptoms. Many patients with nonspecific pain, which may have a psychogenic component, continue to experience similar pain after cholecystectomy. There are problems in determining the symptom status of patients. Patients who believe surgery will relieve symptoms may maximize their symptoms, whereas patients who are reluctant to undergo surgery may minimize their symptoms. Although cholecystectomy is the mainstay of gallstone treatment, bile acid therapy and, if available, ESWL and topical dissolution are nonsurgical treatment alternatives in selected patients. In selected cases, in particular in the elderly and in other patients at increased risk from surgery, nonsurgical management offers lower morbidity and mortality than does operative treatment. The decision for surgical versus nonsurgical management should be based on both objective selection criteria and patient choice.

[Changes in and acceptance of surgical and noninvasive therapy procedures in cholecystolithiasis]

BACKGROUND

The treatment of cholecystolithiasis has changed fundamentally in recent years due to the development of non-surgical techniques (extracorporeal shockwave lithotripsy [ESWL], oral litholysis) and the implementation of laparoscopic cholecystectomy.

PATIENTS AND RESULTS

Retrospective analysis of 2270 patients (1649 women, 621 men; age: 47.2 +/- 14 years) presenting with gallstone disorders in a university medical outpatients department between 1988 and 1992 in order to be instructed as to the most suitable therapy method bear witness to the rapid change in therapeutic procedure. Laparoscopic removal of the gallbladder has virtually supplanted conventional cholecystectomy, and within 5 years the proportionate role of ESWL has declined from 21 to 12%. Over the years, the proportion of patients requiring no therapeutic intervention remained constant (at about 20%). The therapeutic recommendations of the "experts" were implemented in almost 80% of cases. The majority of patients were satisfied with the chosen therapeutic approach (surgery: 93.0%, ESWL: 77.6%), although 44% of ESWL-patients and 36% of surgically managed patients reported complaints which persisted even after completion of therapy. Despite unsuccessful ESWL (residual fragments or recurrent stones) 58/95 (61%) of interviewed patients would again give preference to this non-invasive modality in the event of a renewed therapeutic decision.

CONCLUSION

Only a few years after its introduction, laparoscopic cholecystectomy has asserted itself as the predominant treatment option. But as far as acceptance and preference by the patient are concerned extracorporeal shockwave lithotripsy--as a non-invasive treatment modality--also enjoys high popularity and can be recommended as an alternative to surgery in suitable patients chosen according to the currently established stringent selection criteria.

Dissolution of human cholesterol gallstones in bile salt/lecithin mixtures: effect of bile salt hydrophobicity and various pHs

BACKGROUND

Unconjugated bile salts currently available for gallstone dissolution are poorly effective. We evaluated in vitro the litholytic potency of taurine-amidated bile salts against human cholesterol gallstones.

METHODS

Seventy radiolucent gallstones with similar size and composition (cholesterol content, 70.1 +/- 0.9%) from a single patient were incubated in model biles composed of 100 mM of either taurochenodeoxycholate (TCDC), taurocholate (TC), taurohyodeoxycholate (THDC) or tauroursodeoxycholate (TUDC) and of 45 mM egg yolk lecithin in saline buffered with tris/HCl (at pHs 7 and 8) or phosphate (at pHs 4 and 6). Biles (total lipids, 10 g/dl; cholesterol saturation, 99%) were incubated at 37 degrees C for 40 days. Gallstones were periodically weighed and returned to the dissolution vials, and the biliary cholesterol concentration was monitored.

RESULTS

Model biles remained optically clear during the initial 48 h of incubation. Then, biles containing THDC and TUDC, but not those with TC and TCDC, became progressively turbid until, after several days, a white precipitate surrounded the residual stone. Abundant liquid crytalline droplets were observed at polarizing microscopy in biles containing TUDC and THDC. Gallstone dissolution was closely related to cholesterol solubilization and decreased in the order TCDC > THDC > or = TC > TUDC, being highest at pH 8. At the physiologic pH of 7 THDC was more litholythic than TC.

CONCLUSIONS

In vitro, the litholytic potency of bile salts on cholesterol gallstones primarily depends on their hydrophobicity. THDC is a new potential gallstone-dissolving agent, deserving in vivo studies.

Cost effectiveness of adjuvant bile salt treatment in extracorporeal shock wave lithotripsy for the treatment of gall bladder stones

The relative cost effectiveness of adjuvant urso and chenodeoxycholic acid treatment in extracorporeal shockwave lithotripsy (ESWL) has been assessed as part of a pragmatic randomised controlled trial of ESWL as a treatment of gall bladder stones. Of the first patients with gall stone volume < 4 cm3 randomised to ESWL in the main trial, 24 were randomised to have ESWL alone and 26 to have adjuvant bile acid treatment, one of whom died before the end of the 12 month follow up period. At 12 months after treatment, differences in gall stone clearance between ESWL alone (3/24 (13%) clear, 5 (21%) referred for surgery) and ESWL and bile acids (6/25 (24%) clear, 2 (8%) referred for surgery) were not significant (p = 0.36, log rank test). Patients in both groups had substantial and significant health gains (according to biliary pain frequency and severity, Nottingham Health Profile scores, visual analogue scale symptom scores, and complications) but there were no significant differences between the groups. Improvements in both groups usually occurred within a few weeks of treatment and were unrelated to gall stone clearance. Costs were greater in the bile salt group (95% confidence intervals for estimated cost difference: 90 pounds to 630 pounds). If the purpose of treatment is symptom relief rather than gall stone clearance then adjuvant bile salt treatment seems to be unnecessary.

Natural history and treatment with ursodiol of gallstones formed during rapid loss of weight in man

Cholesterol gallstones form frequently among obese patients during rapid loss of weight. The aims of the present study were to determine the short-term natural history of these gallstones and the efficacy of ursodiol for their dissolution. Twenty-two patients whose gallstones had formed during rapid loss of weight were randomized in double-masked fashion to either ursodiol, 1200 mg/day, or placebo for nine months. Ultrasonography of the gallbladder was performed after three and nine months of treatment. All patients without disappearance of their gallstones after nine months received open-label ursodiol for an additional nine months with ultrasonography after three and nine months. Among the patients completing three months of masked treatment, disappearance of gallstones was seen in five of 11 patients who received placebo and four of seven patients who received ursodiol. Only one additional patient of six continuing placebo for nine months experienced disappearance. Neither of two patients continuing ursodiol for nine months had disappearance of gallstones. None of the five patients treated with open-label ursodiol for nine months had disappearance of gallstones. Thus, half of the gallstones that form during rapid loss of weight disappear rapidly once loss of weight ceases; ursodiol may not increase the frequency or rapidity of their disappearance.

Comparative studies of metabolism of simultaneously administered chenodeoxycholic acid and ursodeoxycholic acid in hamsters

We present the comparative studies of metabolism of chenodeoxycholic acid and ursodeoxycholic acid and their taurine conjugates in the liver and fecal culture from hamsters. When [24-14C]chenodeoxycholic acid and [11,12-3H]ursodeoxycholic acid were simultaneously instilled into the jujunal loop of bile fistula hamsters, both bile acids administered were recovered mainly as their conjugates with taurine and glycine in the fistula bile. The recovery of chenodeoxycholic acid was slightly but significantly higher than that of ursodeoxycholic acid. Chenodeoxycholic acid was more efficiently conjugated with glycine than ursodeoxycholic acid. The glycine/taurine ratio in the biliary chenodeoxycholic acid was 1.9, and that in ursodeoxycholic acid was 1.6. In addition, as much as 6.2% of ursodeoxycholic acid was excreted as the unconjugated form; on the other hand only 2.4% of unconjugated chenodeoxycholic acid was excreted. When [24-14C]chenodeoxycholyltaurine and [11,12-3H]ursodeoxycholyltaurine were simultaneously administered into the ileum loop of bile fistula hamsters, both bile salts were absorbed and secreted efficiently into the bile at the same rate. These results indicate that slightly lower recovery of ursodeoxycholic acid in the bile could be due to the less effective conjugation of ursodeoxycholic acid than chenodeoxycholic acid in the liver. Deconjugation by fecal culture from a hamster proceeded more rapidly in chenodeoxycholyltaurine than ursodeoxycholyltaurine. 7-Dehyroxylation to form lithocholic acid by fecal culture was also faster in chenodeoxycholic acid than ursodeoxycholic acid. The formation of 7-oxolithocholic acid from ursodeoxycholic acid was lesser than from chenodeoxycholic acid. In summary, bacterial deconjugation followed by 7-dehydroxylation to form lithocholic acid seems to be achieved more efficiently with chenodeoxycholic acid than ursodeoxycholic acid.

Current options in gallstone management

Preview Should surgery to remove gallstones be deferred until symptoms occur? When should therapy with oral bile acids, lithotripsy, or methyl tert-butyl ether be considered? How should nonspecific dyspeptic symptoms in a patient with cholelithiasis be managed? Dr Marshall discusses these and other questions and controversies.

Pharmacological treatment of gallstones. Practical guidelines

Laparoscopic cholecystectomy is the treatment of choice for symptomatic cholelithiasis. Medical treatment is indicated for patients who are not fit or are afraid of surgery. For any form of medical treatment to be effective gallstones must be cholesterol rich, thus radiolucent, and the cystic duct must be patent, as indicated by gallbladder opacification on oral cholecystography. Three forms of medical treatment are currently available for clinical use--oral bile acids, bile acids as adjuncts to lithotripsy and contact dissolution using methyltertbutylether. The choice of treatment depends mainly on gallstone size. Gallstones < 6 mm in diameter are best treated with oral bile acids, chenodeoxycholic acid 15 mg/kg/day or ursodeoxycholic acid 10 mg/kg/day given alone or in combination (5 mg/kg/day each). Careful patient selection and bedtime administration of the whole daily bile acid dose enhance treatment, and may achieve up to 75% complete dissolution annually. Single stones < 30 mm in diameter or multiple stones (n < 3) are best treated with lithotripsy combined with oral bile acid for dissolution of fragments. Annual dissolution rates are about 80 and 40% for single and multiple stones, respectively. Stones of any size and number can be dissolved by direct contact dissolution using methyltertbutylether. Dissolution has been reported to be complete in almost 100% of stones, but debris is frequently left behind in the gallbladder. Following dissolution using any form of treatment, gallstones recur in about 50% of patients, and cannot be reliably prevented by low dose bile acid or dietary manipulations. Failing prevention, early detection and retreatment of recurrent stones is the best alternative option as a long term strategy.

Chenodeoxycholate: the bile acid. The drug. a review

Chenodeoxycholate (3 alpha, 7 alpha-dihydroxy-5 beta-cholanic acid) is a primary bile acid directly synthesized from cholesterol. It is an amphipathic molecule, possessing both a hydrophobic side and a polar hydrophilic side, giving it the ability to solubilize lipids in a water environment. Bile acids are necessary for the absorption of fats and fat soluble vitamins. Chenodeoxycholate inhibits the rate-limiting step of cholesterol synthesis, the formation of hydroxymethyl-glutaryl-coenzyme A. It was first reported to be useful in the dissolution of cholesterol gallstones in 1972. Today, chenodeoxycholate has other medicinal uses and is used for the management of cerebrotendinous xanthomatosis, hypertriglyceremia, congenital liver diseases, rheumatoid arthritis, and constipation. This article details some finer points of chenodeoxycholate biochemistry and physiology and discusses in some detail the current and past clinical uses of chenodeoxycholate. This is not an exhaustive discussion on gallstone dissolution therapies, but an overview of some of the lesser-known uses for this drug.

Ursodeoxycholic acid treatment of cholesterol gallstone disease

Bile acid dissolution therapy alone or in combination with extracorporeal shock-wave lithotripsy continues to be a safe and effective non-surgical treatment for highly selected patients with cholesterol gallstone disease. Its disadvantages are the duration of drug treatment and potential stone recurrence. Its advantages, however, are non-invasiveness, low rate of morbidity, and lack of mortality. Considering the variety of options in modern gallstone therapy, the careful selection of treatment should be tailored to the individual patient's clinical and personal situation. This will involve the patient in the decision-making process.

Duodenal bile examination in identifying potential non-responders to bile salt treatment and its comparison with gall bladder bile examination

The results of bile salt treatment in patients with radiolucent stones and a functioning gall bladder have been poor. In 42 of these patients awaiting cholecystectomy we determined the value of duodenal bile examination in predicting gall stone composition, and thus identifying those less likely to respond to bile salt therapy. Based on chemical analysis and scanning electron microscopy, 28 of 42 (67%) gall stones retrieved at surgery were potentially insoluble. Microscopic examination of duodenal bile correctly identified 21 (75%) of them: it predicted all four (100%) pigment stones, three of six (50%) calcium carbonate containing cholesterol stones, and 14 of 18 (78%) cholesterol stones with pigment shells. It was nearly as reliable as microscopic examination of bile aspirated directly from the gall bladder during surgery (21 (75%) v 23 (82%); p = NS). Furthermore, the presence of cholesterol crystals in duodenal bile was a more sensitive indicator than chemical detection of supersaturation (34 of 38 (89%) v 25 of 35 (71%); p < 0.05) for prediction of cholesterol gall stones. Microscopic examination of duodenal bile, if used as a screening test, could help to exclude potential non-responders and thereby improve considerably the results of oral bile salt treatment for gall stone dissolution.

Gallstone recurrence after shock-wave therapy

BACKGROUND/AIMS

The long-term outcome of nonoperative gallstone therapy depends on both absence of stones and absence of biliary pain. The aim of the present study was to determine the rate of stone recurrence and the rate of symptoms within 5 years after successful shock wave lithotripsy combined with bile acid therapy.

METHODS

One hundred consecutive patients (single stones, n = 89; 2 or 3 stones, n = 11) were followed up for a median of 4.3 years after stone disappearance and discontinuation of bile acids.

RESULTS

Twenty-three of the 100 patients developed recurrent stones. Calculated by actuarial analysis, the recurrence rate was 7% +/- 3%, 11% +/- 3%, 13% +/- 4%, 20% +/- 5%, and 31% +/- 7% (mean +/- SD) at 1, 2, 3, 4, and 5 years, respectively. The recurrent stones were small (6 +/- 5 mm) and were associated with recurrent biliary pain in 14 (61%) of the 23 patients. Repeated shock wave lithotripsy and/or bile acid medication resulted in stone disappearance in only 10 of 20 patients with recurrence.

CONCLUSIONS

The long-term rate of stone recurrence after lithotripsy of primarily solitary gallbladder calculi is lower than expected from post-bile acid dissolution trials. Recurrence of stones frequently is associated with recurrence of biliary pain.

Transhepatic topical dissolution of gallbladder stones with MTBE and EDTA. Results, side effects, and correlation with CT imaging

Forty-two patients with symptomatic gallstones (28 women, 14 men, mean age 49.8 +/- 13.2 years) were recruited for contact dissolution therapy. Pretreatment CT scans of the gallbladder were obtained in every patient under standard conditions. For contact dissolution treatment of heterogeneous gallstones or gallstones with attenuation values of more than 50 Hounsfield units, methyl tert-butyl ether and bile acid ethylene diaminetetraacetic acid were used in alternating administration at time intervals and durations adapted to the individual tolerance of the patients. In the case of gallstones with mean attenuation values under 50 Hounsfield units, the dissolution therapy was performed with methyl tert-butyl ether alone. In 12 (28.6%) patients a complete dissolution of gallbladder stones could be achieved; 11 patients (26.2%) revealed gallbladder sludge but no radiologically or sonographically visualized residual stone debris. The remaining 19 (45.2%) patients had residual gallstone debris. Shell fragments in three of five rimmed gallstones, seven of eight laminated gallstones, and all densely calcified stones were refractory to contact dissolution therapy. Dissolution rates correlated well with mean attenuation values, whereas no significant correlation was found between stone number and dissolution rates or between stone diameter and dissolution rates respectively. The mean instillation time required for stones with a mean density of more than 50 HU was 17.7 +/- 11.5 hr of bile acid ethylene diaminetetraacetic acid and 5.8 +/- 3.2 hr of methyl tert-butyl ether. In the case of isodense stones, the average instillation time of methyl tert-butyl ether was 12.3 +/- 4.7 hr.(ABSTRACT TRUNCATED AT 250 WORDS)

Overview of therapeutic modalities for the treatment of gallstone diseases

The management of gallstone diseases has been revolutionized in less than 2 years by the advent of laparoscopic cholecystectomy (LC). However, the rapid adoption of LC has occurred without comparative randomized trials with other available therapies. Thus, the evaluation of LC versus other therapies can only be based on case series. The criteria used for this evaluation are clinical effectiveness, cost-effectiveness, and the patient's level of acceptance and satisfaction with the procedure. The techniques of both LC and open cholecystectomy (OC) have the advantage over other approaches, such as extracorporeal shock-wave lithotripsy or bile acid therapy, of eliminating not only the gallstones but also the gallbladder, thereby preventing recurrence of the disease. Additionally, medical therapies are effective in only a subgroup of patients. Since the complications of surgery are more frequent and more severe in older patients and, due to life expectancy, the risk of recurrence is lower in this population, cost-effectiveness analyses have shown that medical therapies may be preferable in older patients in the subgroup eligible for the respective medical therapies. Compared with OC, LC results in a reduction in hospital stay and time to return to work, in lower cost, and in higher patient satisfaction with the procedure. However, a major concern with the laparoscopic approach has been an increase in the incidence of bile duct injury, particularly during the learning phase of the procedure. Clearly, this problem must be solved. The development of training courses in laparoscopy and the adoption of rigorous criteria for ductal identification are critical in preventing such injuries. Bile duct injury can probably be reduced at least to the level of OC (about 1 in 1,000). Acute cholecystitis may also be treated by LC, but the safety and timing of surgery should be conclusively evaluated. Patients with gallbladder stones and choledocholithiasis are usually treated by endoscopic sphincterotomy either before or soon after laparoscopic surgery. Laparoscopic techniques of common bile duct exploration that will obviate the need for endoscopic sphincterotomy are in the developmental stages. When such a technique is available, comparative trials with endoscopic sphincterotomy will be necessary to assess the best approach.

Oral and contact dissolution of gallstones

The appropriate selection of patients for treatment with oral ursodeoxycholic acid (UDCA)--a drug that has virtually no side effects--results in about 50% of patients experiencing safe dissolution of gallstones within 2 years. Eligible patients have small (less than 20 mm in diameter) radiolucent gallstones in a gallbladder visualized by oral cholecystography (OCG); ideal candidates are thin women who have gallstones that are less than 15 mm in diameter, floating when observed by OCG, or of low density on computed tomographic (CT) scanning. Contact dissolution with methyl tert-butyl ether (MTBE) is rapid, effective more often than UDCA, and safe but requires the expertise of an interventional radiologist. Any size and number of cholesterol gallstones that are not CT-dense will be dissolved by MTBE, leaving at most only insoluble debris that is clinically innocuous. Although gallstones recur after dissolution by UDCA or MTBE in 50% of patients within 5 years, recurrent gallstones are usually asymptomatic and/or can probably be dissolved. We conclude that oral or contact dissolution provides an alternative treatment to cholecystectomy for about 30% of patients with symptomatic gallstones.

Efficacy of bile acid therapy for gallstone dissolution: a meta-analysis of randomized trials

To define better the efficacy of bile acid therapy for dissolution of radiolucent gallstones, we performed a meta-analysis of published trials from January 1966 to September 1992. Studies were identified using a MEDLINE computer search followed by an extensive manual search. The inclusion criteria used were: randomized trial, radiolucent gallstones in a visualizing gallbladder on oral cholecystography, and complete stone dissolution confirmed by oral cholecystography or ultrasound. Study results were pooled into 6 groups: placebo: high- and low-dose chenodeoxycholic acid (CDCA) (> or = 10 mg.kg/day and < 10 mg.kg/day); high- and low-dose ursodeoxycholic acid (UDCA) (> or = 7 mg.kg/day and < 7 mg.kg/day) and combined CDCA plus UDCA. Homogeneity calculations were performed and the percentage of complete stone dissolution calculated for each group with 95% confidence intervals. Of 66 trials identified, 23 comprising 1949 patients met the inclusion criteria. A total of 1062 patients were treated with CDCA, 819 with UDCA and 78 combination therapy. In studies > 6 months' duration, high-dose UDCA completely dissolved stones in 37.3% of patients (95% C.I. 33-42%), low-dose UDCA in 20.6%) and high-dose CDCA 18.2% (95% C.I. 15-21%). Based on only two studies, combination therapy achieved dissolution in 62.8% (95% C.I. 51-74%) of patients. Stones less than 10 mm dissolved significantly more frequently than stones larger than 10 mm. This analysis shows that UDCA in doses greater than 7 mg.kg/day taken for greater than 6 months will dissolve radiolucent gallstones in 38% of patients. The combination of UDCA and CDCA may be more efficacious but this observation is based upon only 78 patients and requires confirmation in further randomized trials.

Clinical, ultrasonographic, and roentgenographic study in 134 asymptomatic gallstone carriers. Is oral ursodeoxycholic acid treatment worthwhile?

We investigated retrospectively the ultrasonographic and roentgenographic characteristics of the gallstones and the gallbladder in 134 symptom-free carriers and evaluated prospectively the outcome and side effects of 6 to 24 months' ursodeoxycholic acid (UDCA) therapy in 36 individuals with silent stones. Two-thirds of the 134 subjects had multiple stones, and 71-75% had stones less than 15 mm in diameter. Gallstone calcification was detected in 13%. A non-functioning gallbladder was observed in 19%, whereas gallbladder contraction was normal in 64 of 76 gallstone carriers. With regard to oral bile acid treatment, complete and partial dissolutions were achieved in 7 and 9 of 33 subjects, respectively (48.5%). Development of a non-functioning gallbladder occurred in 9%, and acquired gallstone calcification was seen in another 15%. We conclude that: i) the characteristics of the gallstones and the gallbladder are similar to those observed in symptomatic patients, and ii) UDCA therapy may be given in selected symptom-free carriers for no more than 6-12 months. Thereafter, it does not appear to be cost-effective.

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.

Extracorporeal shock wave lithotripsy combined with litholytic therapy in the treatment of patients with symptomatic gallstones--the Melbourne experience

OBJECTIVE

To investigate the role of extracorporeal shock wave lithotripsy using the Dornier MPL9000 lithotripter and adjuvant litholytic therapy in the treatment of symptomatic gallbladder stones.

PATIENTS AND METHODS

Between August 1989 and March 1991, 399 patients had their one to three gallbladder stones fragmented by the Dornier MPL9000 lithotripter. Chenodeoxycholic acid alone was used as adjuvant litholytic therapy in the majority. A minority received a combination of chenodeoxycholic acid and ursodeoxycholic acid or ursodeoxycholic acid alone. Patients who died, had cholecystectomies or failed to complete the treatment program were excluded from analysis, leaving a cohort of 287 patients with a follow-up of at least 12 months. This cohort comprised 173 patients with single small stones (20 mm or less in diameter), 32 patients with single large stones (21 mm to 30 mm in diameter) and 82 patients with two to three stones.

OUTCOME MEASURES

Patients were followed up by repeated ultrasound examination to monitor the disappearance of fragments from the gallbladder. Stone-free rates, recurrences and complications of treatment were determined.

RESULTS

The stone-free rate 12 months after treatment was 37.6% for patients with a single small stone, 3.1% for patients with a single large stone and 18.3% for patients with two to three stones. Of 70 patients with a single small stone who had become stone free at some time during the 12 months after treatment, five (7.1%) experienced recurrence, as did one of the 16 patients (6.9%) with two to three stones. Some 179 patients (44.9%) experienced biliary colic after lithotripsy. Most attacks were mild. Eleven patients (2.8%) developed cholecystitis and nine (2.3%) became jaundiced. Five patients (1.3%) suffered from pancreatitis, of whom one died from severe necrotising pancreatitis. Treatment mortality was 0.25%. Cholecystectomy was needed in 44 patients (11.9%).

CONCLUSIONS

Only about 15%-20% of all patients with symptomatic gallbladder stones are suitable for lithotripsy. In this study, only about 28% were stone free after 12 months. As the gallbladder is not removed, stones may re-form. Laparoscopic cholecystectomy and open cholecystectomy by comparison will produce a "stone-free state" in 100% of patients, no matter how many stones are present in the gallbladder, their size, or whether the gallbladder is non-functioning. Consequently, lithotripsy and litholytic therapy are now reserved for those few patients who are unable to tolerate general anaesthesia and cholecystectomy and those who refuse surgery. Even in centres showing the most favourable results, lithotripsy and litholytic therapy will have at best a minor role to play in the overall management of symptomatic gallbladder stones.

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.

Management of recurrent gallstones

The risk of gallstone recurrence following non-surgical treatment has been overestimated in the past for two reasons: (1) diagnosis of primary gallstone dissolution was based on oral cholecystography; and (2) gallstone recurrence was expressed as a cumulative recurrence rate. Results based on better methodologies for diagnosis of gallstones (ultrasonography) and for calculation of results (life-table analysis) have indicated that gallstones recur in about 50% of patients, and that the risk of recurrence is confined mainly to the first 5 years after dissolution. Pretreatment gallstone characteristics, but not patient characteristics, are important risk factors for gallstone recurrence. Multiple stones are more likely to recur than solitary stones, a phenomenon attributable to the presence of a potent pronucleating factor in the bile of patients with multiple stones. This observation, and the finding that NSAID administration may reduce gallstone recurrence via inhibition of mucin secretion, suggests that the nucleation defect might be a key factor in the pathogenesis of recurrent gallstones. Prophylaxis with low-dose CDCA or UDCA has proven ineffective for preventing gallstone recurrence, although it may reduce it. Since the majority of recurrent gallstones are small when first seen because of regular ultrasonographic follow-up, multiple, radiolucent and in functioning gallbladders, they are amenable to bile acid retreatment, and intermittent bile acid therapy is probably a viable strategy for long-term management of cholesterol cholelithiasis.

Bile acid dissolution therapy of gallbladder stones

Oral cholelitholytic bile acid therapy has become established treatment for selected patients with cholesterol gallstones. The treatment finds its clinical application both alone and in combination with ESWL. UDCA alone or, less commonly, a combination of this bile acid with CDCA is used. Optimal results can be expected only in carefully selected patients. Bile acid dissolution therapy is most successful in patients with radiolucent gallstones which are < or = 0.5 cm in diameter or are shown by OCG to be floating. Dissolution is seldom seen when the stones are > 1 cm in size. Cholelitholytic treatment in combination with ESWL yields optimal results in single radiolucent gallstones which are not greater than 2 cm. ESWL thus makes it possible to use medical treatment effectively in single 1-2 cm gallstones when bile acids alone would not be successful. Bile acid treatment is extremely safe, especially if UDCA is given without the addition of CDCA.

Gallstone disease. Pathophysiology, epidemiology, natural history, and treatment options

In 1991, only symptomatic gallstones should be treated. The treatment of choice for all gallstones continues to be surgical removal. Except for stones in the common bile duct, which are amenable to removal by endoscopic papillotomy, nonsurgical treatment of gallstones should be investigated further before it can have widespread applicability. The major challenge in the future may be medical prevention of gallstone formation in susceptible individuals. Laparoscopic cholecystectomy seems to have moved to the forefront of surgical therapy in patients who are candidates for the procedure.

Extracorporeal shock-wave lithotripsy and ursodiol versus ursodiol alone in the treatment of gallstones

The efficacy and occurrence of adverse effects after two forms of treatment were compared in 111 patients with biliary colic and radiolucent gallstones in this prospective, nonrandomized study. Fifty-four patients received extracorporeal shock-wave lithotripsy (ESL) plus ursodiol, and 57 patients received ursodiol alone. Among patients with a single stone (5-20 mm in size), no patient treated with ursodiol alone had a stone-free gallbladder at 6 or 12 months after treatment; of those treated with ESL plus ursodiol, 15 of 24 patients (63%) had a stone-free gallbladder at 6 months and 17 of 20 patients (85%) at 12 months. For patients with multiple stones (with an aggregate diameter of less than or equal to 30 mm), the incidence of a stone-free gallbladder was 2 of 43 patients (5%) at 6 months and 8 of 35 patients (23%) at 12 months in the ursodiol treatment group. In the ESL plus ursodiol group, the incidence of a stone-free gallbladder was 7 of 22 patients (32%) at 6 months and 9 of 20 patients (45%) at 12 months. Two patients in the ESL plus ursodiol group (4%) and 13 patients in the ursodiol group (24%) underwent cholecystectomy. Both patients in the ESL plus ursodiol therapy and 4 patients in the ursodiol group had emergency cholecystectomies because of acute cholecystitis. The remaining 9 patients in the ursodiol group had elective cholecystectomies. In this nonrandomized, prospective study, ESL plus ursodiol treatment produced stone-free gallbladders at a faster rate than ursodiol alone in patients with either single or multiple gallstones.