Ten years experience with piezoelectric extracorporeal shockwave lithotripsy of gallbladder stones

Management of Gallstone Disease

Gallstone disease has plagued humanity since antiquity. Its recognition and treatment has been refined through decades as surgical technique and imaging capabilities have advanced. With the rise of the obesity epidemic and metabolic syndrome, its prevalence is also increasing. This review provides an overview of the various manifestations of gallstone disease and treatment modalities appropriate for its resolution.

Predictive value of bile acids as metabolite biomarkers for gallstone disease: A systematic review and meta-analysis

BACKGROUND

The profiles of bile acids (BAs) in patients with gallstone disease (GSD) have been found to be altered markedly though in an inconsistent pattern. This study aims to characterize the variation of the BA profiles in GSD patients, thereby to discover the potential metabolite biomarkers for earlier detection of GSD.

METHODS

Literature search of eight electronic database in both English and Chinese was completed on May 11, 2023. The qualitative and quantitative reviews were performed to summarize the changes of BA profiles in GSD patients compared with healthy subjects. The concentrations of BAs were adopted as the primary outcomes and the weighted mean differences (WMDs) and 95% confidence interval (CI) were generated by random-effects meta-analysis models.

RESULTS

A total of 30 studies were enrolled which included 2313 participants and reported the 39 BAs or their ratios. Qualitative review demonstrated serum Taurocholic Acid (TCA), Glycochenodeoxycholic acid (GCDCA), Glycocholic acid (GCA), Taurochenodeoxycholic acid (TCDCA), Glycodeoxycholic acid (GDCA) and Deoxycholic acid (DCA) were significantly increased in GSD patients compared with healthy subjects. Meta analysis was performed in 16 studies and showed that serum Total BAs (TBA) (WMD = 1.36μmol/L, 95%CI = 0.33; 2.4) was elevated however bile TBA (WMD = -36.96mmol/L, 95%CI = -52.32; -21.6) was declined in GSD patients. GCA (WMD = 0.83μmol/L, 95%CI = 0.06; 1.6) and TCA (WMD = 0.51μmol/L; 95%CI = 0.18; 0.85) were both increased in serum sample; TCDCA (WMD = 2.64mmol/L, 95%CI = 0.16; 5.12) was rising, however GCDCA (WMD = -13.82mmol/L, 95%CI = -21.86; -5.78) was falling in bile sample of GSD patients. The level of serum DCA in the GSD patients was found to be increased by using chromatography, yet decreased by chromatography mass spectrometry.

CONCLUSION

The profiles of BAs demonstrated distinctive changes in GSD patients compared with healthy control subjects. Serum GCA, TCA and GCDCA, as the typically variant BAs, presented as a potential marker for earlier diagnosis of GSD, which could facilitate early prophylactic intervention. Yet, further validation of these biomarkers by longitudinal studies is still warranted in the future. PROSPERO registration number CRD42022339649.

Cholesterol cholelithiasis: part of a systemic metabolic disease, prone to primary prevention

Cholesterol gallstone disease have relationships with various conditions linked with insulin resistance, but also with heart disease, atherosclerosis, and cancer. These associations derive from mechanisms active at a local (i.e. gallbladder, bile) and a systemic level and are involved in inflammation, hormones, nuclear receptors, signaling molecules, epigenetic modulation of gene expression, and gut microbiota. Despite advanced knowledge of these pathways, the available therapeutic options for symptomatic gallstone patients remain limited. Therapy includes oral litholysis by the bile acid ursodeoxycholic acid (UDCA) in a small subgroup of patients at high risk of postdissolution recurrence, or laparoscopic cholecystectomy, which is the therapeutic radical gold standard treatment. Cholecystectomy, however, may not be a neutral event, and potentially generates health problems, including the metabolic syndrome. Areas covered: Several studies on risk factors and pathogenesis of cholesterol gallstone disease, acting at a systemic level have been reviewed through a PubMed search. Authors have focused on primary prevention and novel potential therapeutic strategies. Expert commentary: The ultimate goal appears to target the manageable systemic mechanisms responsible for gallstone occurrence, pointing to primary prevention measures. Changes must target lifestyles, as well as experimenting innovative pharmacological tools in subgroups of patients at high risk of developing gallstones.

The physical presence of gallstone modulates ex vivo cholesterol crystallization pathways of human bile

BACKGROUND

Cholesterol crystallization is an essential step toward gallstone formation. Although model bile studies showed that competition occurs between the gallstone surface and the surrounding aqueous phase for cholesterol molecules available for crystallization, this has not been investigated in human bile.

METHODS

Fresh gallbladder bile was obtained during laparoscopic cholecystectomy from 13 patients with cholesterol (n = 10) or pigment (n = 3) stones. Small cholesterol gallstones were collected from another two patients. Both native and ultrafiltered bile with or without added gallstones was analysed by polarized light microscopy for the presence of arc-like and needle-like anhydrous cholesterol crystals and classic cholesterol monohydrate crystals. Weight of the added stones was evaluated before and after 21 days of bile incubation.

RESULTS

In unfiltered bile, the presence of stones was associated with a trend towards less anhydrous cholesterol crystals, but significantly more aggregated cholesterol monohydrate crystals. In ultrafiltered bile, the presence of stones tended to inhibit the formation of arc-like or needle-like crystals and was associated with significantly greater amounts of both plate-like and aggregated cholesterol monohydrate crystals. After 21 days of the incubation, stone weight was decreased in both unfiltered (-4.5 ± 1.6%, P = 0.046) and ultrafiltered bile (-6.5 ± 1.5%, P = 0.002). Bile from pigment-stone patients was clear in the absence of stones, but showed early appearance of plate-like and aggregated cholesterol monohydrate crystals in all samples to which cholesterol gallstones were added.

CONCLUSIONS

The physical presence of cholesterol gallstones in both native and filtered bile greatly influences cholesterol crystallization pathways. Whereas cholesterol monohydrate crystals increase, anhydrous cholesterol crystals tend to be inhibited. Detachment of solid cholesterol crystals from the gallstone surface may explain these findings.

[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.

Recent advances in understanding and managing cholesterol gallstones

The high prevalence of cholesterol gallstones, the availability of new information about pathogenesis, and the relevant health costs due to the management of cholelithiasis in both children and adults contribute to a growing interest in this disease. From an epidemiologic point of view, the risk of gallstones has been associated with higher risk of incident ischemic heart disease, total mortality, and disease-specific mortality (including cancer) independently from the presence of traditional risk factors such as body weight, lifestyle, diabetes, and dyslipidemia. This evidence points to the existence of complex pathogenic pathways linking the occurrence of gallstones to altered systemic homeostasis involving multiple organs and dynamics. In fact, the formation of gallstones is secondary to local factors strictly dependent on the gallbladder (that is, impaired smooth muscle function, wall inflammation, and intraluminal mucin accumulation) and bile (that is, supersaturation in cholesterol and precipitation of solid crystals) but also to "extra-gallbladder" features such as gene polymorphism, epigenetic factors, expression and activity of nuclear receptors, hormonal factors (in particular, insulin resistance), multi-level alterations in cholesterol metabolism, altered intestinal motility, and variations in gut microbiota. Of note, the majority of these factors are potentially manageable. Thus, cholelithiasis appears as the expression of systemic unbalances that, besides the classic therapeutic approaches to patients with clinical evidence of symptomatic disease or complications (surgery and, in a small subgroup of subjects, oral litholysis with bile acids), could be managed with tools oriented to primary prevention (changes in diet and lifestyle and pharmacologic prevention in subgroups at high risk), and there could be relevant implications in reducing both prevalence and health costs.

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.

Lessons learnt from a case of extracorporeal shockwave lithotripsy for a residual gallbladder stone

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ECSWL failed to treat a residual gallbladder stone after failed cholecystectomy.

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Even if a stone is fractured, it may not be expelled by a diseased gallbladder.

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ECSWL should be followed by endoscopic retrieval to complete treatment.

Introduction

Extracorporeal shockwave lithotripsy (ECSWL) for gallstones is rarely used due to high recurrence rates, but has been reported to be effective in some circumstances.

Presentation of case

We describe a case of a failed attempt at laparoscopic cholecystectomy due to gallbladder contraction and complete obliteration of Calot’s triangle. Cholecystotomy was performed to remove all visible stones, and completed by a subtotal cholecystectomy and closure of the gallbladder remnant. The patient remained symptomatic due to a residual stone in the Hartmann’s pouch. ECSWL was attempted to fragment the stone; however, follow-up imaging showed persistence of the calculus.

Discussion

Literature review shows that ECSWL for multiple gallbladder stones has a low success rate. Even if a stone is successfully fragmented, a diseased gallbladder remnant seems incapable of expelling the fragments. Without completion endoscopic clearance, therefore, the treatment is considered incomplete.

Conclusion

Our case suggests that ECSWL is ineffective in management of residual gallbladder stones after failed cholecystectomy.

Risk factors for gallbladder contractility after cholecystolithotomy in elderly high-risk surgical patients

Objective

Cholecystolithiasis is a common disease in the elderly patient. The routine therapy is open or laparoscopic cholecystectomy. In the previous study, we designed a minimally invasive cholecystolithotomy based on percutaneous cholecystostomy combined with a choledochoscope (PCCLC) under local anesthesia.

Methods

To investigate the effect of PCCLC on the gallbladder contractility function, PCCLC and laparoscope combined with a choledochoscope were compared in this study.

Results

The preoperational age and American Society of Anesthesiologists (ASA) scores, as well as postoperational lithotrity rate and common biliary duct stone rate in the PCCLC group, were significantly higher than the choledochoscope group. However, the pre- and postoperational gallbladder ejection fraction was not significantly different. Univariable and multivariable logistic regression analyses indicated that the preoperational thickness of gallbladder wall (odds ratio [OR]: 0.540; 95% confidence interval [CI]: 0.317–0.920; P=0.023) and lithotrity (OR: 0.150; 95% CI: 0.023–0.965; P=0.046) were risk factors for postoperational gallbladder ejection fraction. The area under receiver operating characteristics curve was 0.714 (P=0.016; 95% CI: 0.553–0.854).

Conclusion

PCCLC strategy should be carried out cautiously. First, restricted by the diameter of the drainage tube, the PCCLC should be used only for small gallstones in high-risk surgical patients. Second, the usage of lithotrity should be strictly limited to avoid undermining the gallbladder contractility and increasing the risk of secondary common bile duct stones.

Preventing a Mass Disease: The Case of Gallstones Disease: Role and Competence for Family Physicians

Gallstone formation is the result of a complex interaction between genetic and nongenetic factors. We searched and reviewed the available literature to define how the primary prevention of gallstones (cholesterol gallstones in particular) could be applied in general practice. Electronic bibliographical databases were searched. Prospective and retrospective cohort studies and case-controlled studies were analyzed and graded for evidence quality. The epidemiological data confirmed that genetic factors are estimated to account for only approximately 25% of the overall risk of gallstones, while metabolic/environmental factors are at least partially modifiable in stone-free risk groups, and are thus modifiable by primary prevention measures related to diet, lifestyle, and environmental factors (i.e., rapid weight loss, bariatric surgery, somatostatin or analogues therapy, transient gallbladder stasis, and hormone therapy). There is no specific recommendation for the secondary prevention of recurrent gallstones. Family physicians can contribute to preventing gallstones due to their capability to identify and effectively manage several risk factors discussed in this study. Although further studies are needed to better elucidate the involvement of epigenetic factors that may regulate the effect of environment and lifestyle on gene expression in the primary prevention of gallstone formation, preventive interventions are feasible and advisable in the general practice setting.

Determinants of Detection of Stones and Calcifications in the Hepatobiliary System on Virtual Nonenhanced Dual-energy CT

Objective To retrospectively determine the features of stones and calcifications in hepatobiliary system on virtual nonenhanced (VNE) dual-energy computed tomography (CT), and to evaluate the possibility of VNE images in diagnosis for those lesions.Methods A total of 128 gall stones and calcifications of the liver found in 110 patients were examined with triple phase abdominal CT scan from July 2007 to December 2011, in which true nonenhanced (TNE) phase and arterial phase were performed with single-energy CT (120 kVp) and portal venous phase was performed with dual-energy CT (100 kVp and 140 kVp). VNE images were generated from the portal venous phase dual-energy CT data sets by using commercially VNC software. The mean CT values for the stone, liver, bile and paraspinal muscle, mean lesion density and size in area dimension, contrast-to-noise ratio (CNR) of lesion to the liver or bile, and image noise were assessed and compared between VNE and TNE images. The effective dose and size-specific dose estimate (SSDE) were also calculated.Results The mean CT values of the lesions measured on VNE images declined significantly compared with those measured on TNE images (164.51±102.13 vs. 290.72±197.80 HU, P<0.001), so did the lesion-to-liver CNR (10.80±11.82 vs.18.81±17.06, P<0.001) and the lesion-to-bile CNR (17.24±14.41 vs. 21.32±17.31, P<0.001). There was no significant difference in size of lesions area between VNE and TNE images (0.69±0.88 vs. 0.72±0.85 cm², P=0.062). Compared to the 128 lesions found in TNE images, VNE images showed the same density in 30 (23.4%) lesions, lighter density in 88 (68.8%) lesions, while failed to show 10 (7.8%) lesions, and showed the same size in 61 (47.7%) lesions and smaller size in 57 (44.5%) lesions. The CT cutoff values of lesion and size were 229.21 HU and 0.15 cm², respectively. The total effective dose for triple phase scan protocol with TNE images was 19.51±7.03 mSv, and the SSDE was 39.84±11.10 mGy. The effective dose for dual phase scan protocol with VNE images instead of TNE images was 13.29±4.89 mSv, and the SSDE was 27.83±9.99 mGy. Compared with TNE images, the effective dose and SSDE of VNE images were down by 32.05%±3.69 % and 30.63%±2.34 %, respectively.Conclusions Although the CT values and CNR of the lesions decreased in VNE images, the lesions of which attenuation greater than 229.21 HU and size larger than 0.15 cm² could be detected with good reliability and obvious dose reduction. There was good consistency in the size of stones and calcifications in hepatobiliary system between VNE images and TNE images, which ensured the possibility of the clinical application of VNE images.

Gallstones

Gallstones grow inside the gallbladder or biliary tract. These stones can be asymptomatic or symptomatic; only gallstones with symptoms or complications are defined as gallstone disease. Based on their composition, gallstones are classified into cholesterol gallstones, which represent the predominant entity, and bilirubin ('pigment') stones. Black pigment stones can be caused by chronic haemolysis; brown pigment stones typically develop in obstructed and infected bile ducts. For treatment, localization of the gallstones in the biliary tract is more relevant than composition. Overall, up to 20% of adults develop gallstones and >20% of those develop symptoms or complications. Risk factors for gallstones are female sex, age, pregnancy, physical inactivity, obesity and overnutrition. Factors involved in metabolic syndrome increase the risk of developing gallstones and form the basis of primary prevention by lifestyle changes. Common mutations in the hepatic cholesterol transporter ABCG8 confer most of the genetic risk of developing gallstones, which accounts for ∼25% of the total risk. Diagnosis is mainly based on clinical symptoms, abdominal ultrasonography and liver biochemistry tests. Symptoms often precede the onset of the three common and potentially life-threatening complications of gallstones (acute cholecystitis, acute cholangitis and biliary pancreatitis). Although our knowledge on the genetics and pathophysiology of gallstones has expanded recently, current treatment algorithms remain predominantly invasive and are based on surgery. Hence, our future efforts should focus on novel preventive strategies to overcome the onset of gallstones in at-risk patients in particular, but also in the population in general.

Management of gallstones and its related complications

The majority of gallstone patients remain asymptomatic; however, interest toward the gallstone disease is continuing because of the high worldwide prevalence and management costs and the development of gallstone symptoms and complications. For cholesterol gallstone disease, moreover, a strong link exists between this disease and highly prevalent metabolic disorders such as obesity, dyslipidemia, type 2 diabetes, hyperinsulinemia, hypertriglyceridemia and the metabolic syndrome. Information on the natural history as well as the diagnostic, surgical (mainly laparoscopic cholecystectomy) and medical tools available to facilitate adequate management of cholelithiasis and its complications are, therefore, crucial to prevent the negative outcomes of gallstone disease. Moreover, some risk factors for gallstone disease are modifiable and some preventive strategies have become necessary to reduce the onset and the severity of complications.

Cholesterol cholelithiasis in pregnant women: pathogenesis, prevention and treatment

Epidemiological and clinical studies have found that gallstone prevalence is twice as high in women as in men at all ages in every population studied. Hormonal changes occurring during pregnancy put women at higher risk. The incidence rates of biliary sludge (a precursor to gallstones) and gallstones are up to 30 and 12%, respectively, during pregnancy and postpartum, and 1-3% of pregnant women undergo cholecystectomy due to clinical symptoms or complications within the first year postpartum. Increased estrogen levels during pregnancy induce significant metabolic changes in the hepatobiliary system, including the formation of cholesterol-supersaturated bile and sluggish gallbladder motility, two factors enhancing cholelithogenesis. The therapeutic approaches are conservative during pregnancy because of the controversial frequency of biliary disorders. In the majority of pregnant women, biliary sludge and gallstones tend to dissolve spontaneously after parturition. In some situations, however, the conditions persist and require costly therapeutic interventions. When necessary, invasive procedures such as laparoscopic cholecystectomy are relatively well tolerated, preferably during the second trimester of pregnancy or postpartum. Although laparoscopic operation is recommended for its safety, the use of drugs such as ursodeoxycholic acid (UDCA) and the novel lipid-lowering compound, ezetimibe would also be considered. In this paper, we systematically review the incidence and natural history of pregnancy-related biliary sludge and gallstone formation and carefully discuss the molecular mechanisms underlying the lithogenic effect of estrogen on gallstone formation during pregnancy. We also summarize recent progress in the necessary strategies recommended for the prevention and the treatment of gallstones in pregnant women.

Gallstone disease in children

Gallstone disease in children is evolving, and for the previous 3 decades, the frequency for surgery has increased greatly. This is in part because of improved diagnostic modalities, but also changing pathology, an increased awareness of emerging comorbidities, such as childhood obesity, and other associated risk factors. This article outlines the pathophysiology, genetics, and predisposing factors for developing gallstones and includes a review of the literature on the current and more novel medical and surgical techniques to treat this interesting disease.

Therapy of gallstone disease: What it was, what it is, what it will be

Cholesterol gallstone disease is a common clinical condition influenced by genetic factors, increasing age, female gender, and metabolic factors. Although laparoscopic cholecystectomy is currently considered the gold standard in treating patients with symptomatic gallstones, new perspectives regarding medical therapy of cholelithiasis are currently under discussion, also taking into account the pathogenesis of gallstones, the natural history of the disease and the analysis of the overall costs of therapy. A careful selection of patients may lead to successful non-surgical therapy in symptomatic subjects with a functioning gallbladder harboring small radiolucent stones. The classical oral litholysis by ursodeoxycholic acid has been recently paralleled by new experimental observations, suggesting that cholesterol-lowering agents which inhibit cholesterol synthesis (statins) or intestinal cholesterol absorption (ezetimibe), or drugs acting on specific nuclear receptors involved in cholesterol and bile acid homeostasis, might be proposed as additional approaches for treating cholesterol gallstones. In this review we discuss old, recent and future perspectives on medical treatment of cholesterol cholelithiasis.

Concept of the pathogenesis and treatment of cholelithiasis

Gallstone disease (GD) is a chronic recurrent hepatobiliary disease, the basis for which is the impaired metabolism of cholesterol, bilirubin and bile acids, which is characterized by the formation of gallstones in the hepatic bile duct, common bile duct, or gallbladder. GD is one of the most prevalent gastrointestinal diseases with a substantial burden to health care systems. GD can result in serious outcomes, such as acute gallstone pancreatitis and gallbladder cancer. The epidemiology, pathogenesis and treatment of GD are discussed in this review. The prevalence of GD varies widely by region. The prevalence of gallstone disease has increased in recent years. This is connected with a change in lifestyle: reduction of motor activity, reduction of the physical load and changes to diets. One of the important benefits of early screening for gallstone disease is that ultrasonography can detect asymptomatic cases, which results in early treatment and the prevention of serious outcomes. The pathogenesis of GD is suggested to be multifactorial and probably develops from complex interactions between many genetic and environmental factors. It suggests that corticosteroids and oral contraceptives, which contain hormones related to steroid hormones, may be regarded as a model system of cholelithiasis development in man. The achievement in the study of the physiology of bile formation and the pathogenesis of GD has allowed expanding indications for therapeutic treatment of GD.

Targets for current pharmacologic therapy in cholesterol gallstone disease

Gallstone disease is a frequent condition throughout the world and, cholesterol stones are the most frequent form in Western countries. The standard treatment of symptomatic gallstone subjects is laparoscopic cholecystectomy. The selection of patients amenable for nonsurgical, medical therapy is of key importance; a careful analysis should consider the natural history of the disease and the overall costs of therapy. Only patients with mild symptoms and small, uncalcified cholesterol gallstones in a functioning gallbladder with a patent cystic duct are considered for oral litholysis by hydrophilic ursodeoxycholic acid, in the hope of achieving cholesterol desaturation of bile and progressive stone dissolution. Recent studies have raised the possibility that cholesterol-lowering agents that inhibit hepatic cholesterol synthesis (statins) or intestinal cholesterol absorption (ezetimibe), or drugs acting on specific nuclear receptors involved in cholesterol and bile acid homeostasis, may offer, alone or in combination, additional medical therapeutic tools for treating cholesterol gallstones. Recent perspectives on medical treatment of cholesterol gallstone disease are discussed in this article.

Gallstone disease: from genes to evidence-based therapy

The number of gallstone patients is increasing in ageing populations with a high prevalence of metabolic syndrome and obesity. Recently variants of hepatic ATP binding cassette transporters have been identified as genetic susceptibility factors for gallstone disease, pointing to novel means for risk assessment and prevention. Although laparoscopic cholecystectomy is the mainstay of therapy for symptomatic gallbladder stones, the clinical management of gallstone disease is changing rapidly, with an increase in day case surgery and the advent of transluminal endoscopic surgery. Here, we summarize the molecular and genetic mechanisms of gallstone formation as well as the current evidence-based algorithms for diagnosis and therapy of gallbladder and bile duct stones.

A ten-year prospective study on gallbladder stone recurrence after successful extracorporeal shock-wave lithotripsy

OBJECTIVE

The risk of recurrence has limited the acceptability of conservative therapies of gallbladder stones. The aim of the present study was to determine the long-term rate of stone recurrence and its risk factors after successful extracorporeal shock-wave lithotripsy (ESWL).

MATERIAL AND METHODS

The study comprised a prospective ultrasound follow-up at yearly intervals or whenever biliary pain was reported. A total of 192 consecutive patients (primary single stones, n=159; primary 2 or 3 stones, n=33) were followed for up to 11.2 years after becoming stone-free and after termination of adjuvant treatment with ursodeoxycholic acid (UDCA).

RESULTS

Eighty-four patients developed recurrent stones after a median of 2.6 years (maximum?=?8.8 years). The 108 patients without recurrence were followed for a median of 6.7 years (maximum=11.2 years). By actuarial analysis, the cumulative recurrence rates for these 192 stone-free patients were 27%+/-3%, 41%+/-4% and 54%+/-4% (observed +/-SE) at 3, 5 and 10 years, respectively. Cox's regression analysis was used to identify the presence of slight calcification in the primary stone(s) as a protective feature against recurrence (p=0.03).

CONCLUSIONS

1) The risk of recurrence continues to increase over time, and although it rises less steeply after 5 years, it does not reach a plateau until at least 10 years. 2) Having had slightly calcified stone(s) seems to be associated with a reduced risk of recurrence and might signal a "burnt out" lithogenic process. 3) The long-term results are unsatisfactory and ESWL of gallbladder stones should be offered only in special cases.