Pigment vs cholesterol cholelithiasis: clinical and epidemiological aspects

Gallstones Detection on Dual-Energy Computerized Tomography-Is It Ready for Real-World Use? A Retrospective Observational Study

AIMS

The aims of the study are to evaluate the performance of dual-energy computed tomography (DECT) imaging in the detection of noncalcified gallstones (GSs) and to assess its performance relative to transabdominal ultrasound (US) in identifying cholelithiasis.

METHOD

This study is a retrospective review of radiology records and images to find all patients who had both US and DECT scans within a 6-month period and were found to have GSs. Patients who did not have GSs on US served as the control group. The CT scans were reviewed by 4 radiologists who did not have access to the US results when assessing the presence or absence of GSs on the DECT scans. In case of any discrepancies among the radiologists, the majority opinion was considered. If there was a split opinion, a fifth reviewer was consulted. The data were analyzed to calculate sensitivity, specificity, positive and negative predictive values, as well as overall accuracy and to evaluate interreader variability. The absolute Hounsfield unit (HU) differences of the GSs and bile were compared between polychromatic (PC), virtual noncontrast (VNC), and virtual monochromatic (VMC) images.

RESULTS

Considering at least 3-reader agreement, sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were found to be 92%, 96%, 96%, 92%, and 94%, respectively. Individual reader sensitivity varied between 87% and 92%. There was good interobserver agreement with a Fleiss' kappa of 0.76. Quantification of the whole data set showed that no significant difference was observed in the HU values for the stones between the PC images and the VNC images. A significant increase was observed on the 50-keV VMC images compared with the PC and VNC images. In the study group, 17% stones were visualized only on the VNC or/and 50-keV VMC images, and not on the PC images. On quantitative analysis of these cases, there was a significant increase of HU in the VNC images as compared with PC images and a significant decrease of HU in the 50-keV VMC images as compared with PC images.

CONCLUSIONS

Low-keV images increase stone-bile contrast. Evaluation of cholelithiasis using VNC and 50-keV VMC images demonstrated a 14% increase in sensitivity relative to conventional CT.

Pearl-white gallstones: A report of a case and a chemical analysis by FTIR and XRD

Introduction

Gallstones' color is usually yellow, brown, black or more commonly a mixture of two or more of these colors in different proportions, depending on their composition, with yellow being the most commonly encountered color. Pearl-white gallstones are a very rare entity that has not been studied and reported sufficiently.

Case presentation

Our patient is a 44-year-old lady who was suffering from recurrent attacks of epigastric and right hypochondrial abdominal pain that was aggravated by consumption of fatty meals. Ultrasound Imaging revealed multiple gallbladder stones. After an elective cholecystectomy unusual pearl-white gallstones were found inside a distended gallbladder filled with transparent thick fluid.

Chemical analysis

To evaluate the chemical composition of these stones Fourier-transform infrared (FTIR) spectroscopy and X-Ray Diffraction (XRD) tests were performed and revealed that these stones are composed of cholesterol (99.6%) and calcium carbonate (0.4%).

Discussion

Gallstones are bile depositions of a solid consistency formed inside the gallbladder. Cholesterol, bilirubin, and other substances are involved in the composition of different kinds of gallstones. The presence of gallstones alone inside the gallbladder is usually presented as colicky abdominal pain. Cholecystectomy is a simple surgical removal of the gallbladder from it bed and is the definitive treatment of gallstone disease.

Conclusion

Pearl-white gallstones are rarely encountered and lack information about their pathogenesis, thus prompting further evaluation and studying.

•

Pearl-white coloration of gallstones in extremely rare.

•

FTIR and XRD are useful tools to analyze the chemical composition of gallstones.

•

Cholesterol is the major component of pearl-white gallstones.

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.

Is cholecystectomy necessary after endoscopic treatment of bile duct stones in patients older than 80 years of age?

BACKGROUND AND AIMS

Although patients with cholecystocholedocholithiasis are generally referred to cholecystectomy after endoscopic sphincterotomy (ES) and common bile duct clearance, we often have a conflict whether cholecystectomy is necessary in very elderly patients with comorbid diseases. The aim of this study is to assess whether cholecystectomy in very elderly patients is justified after ES.

PATIENTS AND METHODS

Patients with cholecystocholedocholithiasis who underwent ES and stone extraction and were followed-up for more than 10 years were retrospectively reviewed. We divided these patients into two groups: the elderly group (equal to or more than 80 years old) and young group (less than 80 years old) and compared late biliary complications and mortality.

RESULTS

The 10-year cumulative incidence of overall biliary complications was significantly lower in cholecystectomized patients than in patients with gallbladder in situ in the young group (7.5 vs. 21.7%, p = 0.0037), but not different in the elderly group (8.3 vs. 7.4%, p = 0.92). When each complication was evaluated separately, the rate of recurrent common bile duct stones (CBDS) was not different, but that of acute cholecystitis was significantly lower in the elderly group than in the young group (4.1 vs. 22.6%, p = 0.011).

CONCLUSIONS

In very elderly patients the incidence of acute cholecystitis is low even when the gallbladder is preserved after endoscopic treatment of CBDS, with a similar risk of CBDS recurrence. Thus, it may not be necessary to recommend cholecystectomy after ES for CBDS in very elderly patients.

The aetiology of symptomatic gallstones quantification of the effects of obesity, alcohol and serum lipids on risk. Epidemiological and biomarker data from a UK prospective cohort study (EPIC-Norfolk)

OBJECTIVE

The development of gallstones is influenced by obesity and alcohol. This study aimed to precisely quantify these risks and investigate whether the aetiological mechanism may involve serum lipids, for the first time using a European prospective cohort study.

METHODS

The European Prospective Investigation into Cancer-Norfolk, recruited 25 639 men and women, aged 40 to 74 years, between 1993 and 1997. At enrolment weight, height and alcohol intake were recorded and nonfasting blood samples taken to measure serum triglycerides, cholesterol, high-density lipoproteins and low-density lipoproteins. The cohort was monitored for 14 years for symptomatic gallstones. Cox regression estimated sex-specific hazard ratios (HRs) for symptomatic gallstones adjusted for covariates.

RESULTS

Symptomatic gallstones developed in 296 people (67.9% women). For each additional unit of BMI, the HR in men was 1.08 [95% confidence interval (CI)=1.02-1.14]; in women the HR was 1.08 (95% CI=1.06-1.11). Every unit of alcohol consumed per week decreased risk in men by 3% (HR=0.97, 95% CI=0.95-0.99) with no effect in women. Serum triglycerides increased risk in men (highest vs. lowest quarter HR=2.02, 95% CI=1.03-3.98) and women (HR=2.43, 95% CI=1.52-3.90). Increased high-density lipoprotein was associated with a decreased risk in men (highest vs. lowest quarter HR=0.22, 95% CI=0.09-0.52) and women (HR=0.55, 95% CI=0.36-0.85). No effects were found for serum cholesterol and low-density lipoprotein.

CONCLUSION

Obesity and alcohol influence gallstone formation, possibly in part through their effects on serum lipids. Reducing obesity may prevent gallstones in the population, as 38% of incident cases of gallstones were associated with a BMI of more than 25.

Infectious diseases and the gallbladder

Infections of the gastrointestinal tract can often involve the gallbladder. Infection probably plays a role in the formation of gallstones but is more commonly thought to contribute to acute illness in patients. Acute calculous cholecystitis caused by an impacted gallstone is often complicated by secondary bacterial infection and is a major cause of morbidity and even mortality in patients. A wide variety of organisms can be associated with acute acalculous cholecystitis, a less common but potentially more severe form of acute cholecystitis. This review focuses on infections and their role in the above-mentioned processes involving the gallbladder.

Physical activity reduces the risk of symptomatic gallstones: a prospective cohort study

BACKGROUND AND AIMS

Physical activity may prevent gallstones formation by reducing bile stasis and plasma triglycerides and elevating high-density lipoprotein cholesterol levels. This prospective study investigated the relationship of physical activity and symptomatic gallstones in both sexes, using a questionnaire validated against physiological measurements.

METHODS

A total of 25 639 volunteers, aged 40-74 years, were recruited into the European Prospective Investigation of Cancer, Norfolk and completed a questionnaire recording occupational and recreational physical activity. This questionnaire was validated earlier against measures of energy expenditure and cardio-respiratory fitness. Participants were ranked into four groups of physical activity. The cohort was monitored over 14 years for symptomatic gallstones. The primary outcome was hazard ratios (HR) of developing gallstones at 5 years, calculated using Cox regression modelling. HRs were adjusted for body mass index, alcohol, hormone replacement therapy and parity. Further analysis of a binary variable compared the highest level of physical activity against a combination of the lowest three levels.

RESULTS

After 5 years of follow-up, 135 participants (69.6% women) developed symptomatic gallstones. Comparing the highest level of physical activity against the lowest three levels, the multivariable analysis at 5 years was HR=0.30 (95% confidence interval=0.14-0.64, P=0.002). After 14 years the findings were attenuated (HR=0.70, 95% confidence interval=0.49-1.01, P=0.055).

CONCLUSION

The highest level of physical activity was associated with a 70% decreased risk of symptomatic gallstones after 5 years. This association may be causal as there are consistent experimental and epidemiological data for a protective effect. Physical activity should be accurately measured in studies investigating gallstones aetiology.

Calcium carbonate gallstones in children

BACKGROUND

In the United States, cholesterol stones account for 70% to 95% of adult gallstones and black pigment stones for most of the remainder. Calcium carbonate stones are exceptionally rare. A previous analysis of a small number of pediatric gallstones from the north of England showed a remarkably high prevalence of calcium carbonate stones. The aims of this study were to analyze a much larger series of pediatric gallstones from our region and to compare their chemical composition with a series of adult gallstones from the same geographic area.

METHODS

A consecutive series of gallbladder stones from 63 children and 50 adults from the north of England were analyzed in detail using Fourier transform infrared microspectroscopy. Demographic and clinical data were collected on all patients. The relative proportions of each major stone component were assessed: cholesterol, protein and calcium salts of bilirubin, fatty acids, calcium carbonate, and hydroxyapatite.

RESULTS

Thirty-nine (78%) adults had typical cholesterol stones, 7 (14%) had black pigment bilirubinate stones, and only 2 (4%) had calcium carbonate stones. In contrast, 30 (48%) children had black pigment stones, 13 (21%) had cholesterol stones, 15 (24%) had calcium carbonate stones, 3 (5%) had protein dominant stones, and 2 (3%) had brown pigment stones. In children, cholesterol stones were more likely in overweight adolescent girls with a family history of gallstones, whereas black pigment stones were equally common in boys and girls and associated with hemolysis, parenteral nutrition, and neonatal abdominal surgery. Calcium carbonate stones were more common in boys, and almost half had undergone neonatal abdominal surgery and/or required neonatal intensive care.

CONCLUSION

The composition of pediatric gallstones differs significantly from that found in adults. In particular, one quarter of the children in this series had calcium carbonate stones, previously considered rare. Geographic differences are not the major reason for the high prevalence of calcium carbonate gallstones in children.

HCV infection is a risk factor for gallstone disease in liver cirrhosis: an Italian epidemiological survey

We assessed the prevalence of gallbladder disease (i.e. gallstones plus cholecystectomy) among patients with liver disease and its association with the severity and aetiology of hepatic injury. Subjects, referred to 79 Italian hospitals, were enrolled in a 6-month period. The independent effect of the severity and aetiology of liver disease on gallstone disease prevalence was assessed by multiple logistic regression analysis. Overall, 4867 subjects tested anti-hepatitis C virus (HCV) positive alone, 839 were hepatitis B virus surface antigen (HBsAg) alone, and 652 had an excessive alcohol intake. The prevalence of gallstone disease was 23.3% in anti-HCV-positive patients, 12.4% in HBsAg positive and 24.2% in subjects reporting excessive alcohol intake, respectively. Gallstone disease prevalence increased by age in each aetiological category. The proportion of patients with gallstone disease who had a cholecystectomy was the highest in HCV+ subjects. After adjusting for the confounding effect of age and body mass index, compared with patients with less severe liver disease, subjects with HCV-related cirrhosis, but not those with alcohol-related cirrhosis, were more likely to have gallstone disease. Subjects with HCV-related cirrhosis (OR 2.13, 95% CI: 1.38-3.26) were more likely to have gallstone disease when compared with those with HBV-related cirrhosis. HCV infection is a risk factor for gallstone disease. In Italy, the high prevalence of HCV infection among cirrhotic patients has important implications, as cholecystectomy in these subjects is associated with high risk of morbidity and mortality.

Association between thyroid function and gallstone disease

AIM: To investigate those associations using data of the population-based Study of Health in Pomerania.

METHODS: A study population of 3 749 residents aged 20-79 years without previously diagnosed thyroid disease was available for analyses. Serum TSH was used to assess thyroid function. Cholelithiasis was defined by either a prior history of cholecystectomy or the presence of gallstones on ultrasound. Logistic regression was performed to analyze independent associations between thyroid function and cholelithiasis.

RESULTS: There were 385 persons (10.3%) with low (<0.3 mIU/L), 3 321 persons (88.6%) with normal and 43 persons (1.2%) with high serum TSH levels (>3 mIU/L). The proportion of cholelithiasis among males and females was 14.4% and 25.3%, respectively. Among males, there was an independent relation between high serum TSH and cholelithiasis (OR 3.77; 95%-CI 1.06-13.41; P<0.05). Also among males, there was a tendency towards an elevated risk of cholelithiasis in persons with low serum TSH (OR 1.40; 95%-CI 0.96-2.02; P = 0.07). In the female population, no such relation was identified.

CONCLUSION: There is an association between thyroid and gallstone disease with a gender-specific relation between hypothyroidism and cholelithiasis.

Prevalence and risk factors for gallstone disease

Gallstone disease is a main public health problem. The overall prevalence data range from 3.9% in the pre-echographic era to 13.7% when ultrasonography was used as a diagnostic tool. This study is aimed to determine the prevalence of gallstone disease in a medium income level population in Lima, as well as the relationship with some risk factors: age, sex, familiar history and obesity. A total of 534 adult men and women from a medium economic level underwent ultrasonographic examination of abdomen for detection of gallstone disease (July 2003). The echographic evaluation was performed by 10 general surgeons trained in ultrasonography. Likewise, 4 risk factors--age, gender, familial history, and obesity--were analyzed. Pearson chi2 test (2-sided) was used with a probability of <0.05 for statistical significance and logistic regression analyses for assessment of confounding factors. The prevalence founded was 15%. Eighty-one of 534 participants had lithiasis. Compared to the age group under 30, the odds ratio for the 31 to 50 years and >50 years of age group was 0.9 and 1.1, respectively. The female-male ratio was 1.07 and the odds ratio 0.8. The prevalence of gallstone disease in people reporting a first-degree relative with lithiasis was 21%, whereas in participants without such a condition, it was 13%. On the other hand, a familial history was present in 38% of the lithiasis group and in 25% of the nonlithiasis group. The odds ratio for familial history was 1.8 (P = 0.01, 95% confidence interval 1.1-2.9). The prevalence of the disease for body mass index <24, 25 to 29, and higher than 30 was 17%, 14% and 13%, respectively. Compared to the reference group (body mass index <24), the other 2 groups (body mass index 25-29 and >30) both had a similar odds ratio, 0.8. Logistic regression analyses showed an odds ratio of 1.9 for familiar history (95% confidence interval 1.1-3.2), whereas the odds ratio of the overweight (body mass index 25-29) and obese group (body mass index >30) when compared to the normal group, BMI <24, was 0.7 and 0.9, respectively. The prevalence data for gallstone disease remain slightly higher than those previously reported. Although the familiar history was the only characteristic with a statistically significant positive relationship with lithiasis, additional studies are needed because few biases could not be completely avoided and some confounding factors were not controlled.

Opisthorchiasis-associated biliary stones: Light and scanning electron microscopic study

AIM: Biliary stones are frequently encountered in areas endemic for opisthorchiasis in Thailand. The present study was to describe the prevalence and pathogenesis of these stones.

METHODS: Gallstones and/or common bile duct stones and bile specimens from 113 consecutive cholecystectomies were included. Bile samples, including sludge and/or microcalculi, were examined for Opisthorchisviverrini eggs, calcium and bilirubin. The stones were also processed for scanning electron microscopic (SEM) study.

RESULTS: Of the 113 cases, 82 had pigment stones, while one had cholesterol stones. The other 30 cases had no stones. Most of the stone cases (76%, 63/83) had multiple stones, while the remainder had a single stone. Stones were more frequently observed in females. Bile examination was positive for O.viverrini eggs in 50% of the cases studied. Aggregates of calcium bilirubinate precipitates were observed in all cases with sludge. Deposition of calcium bilirubinate on the eggshell was visualized by special staining. A SEM study demonstrated the presence of the parasite eggs in the stones. Numerous crystals, morphologically consistent with calcium derivatives and cholesterol precipitates, were seen.

CONCLUSION: Northeast Thailand has a high prevalence of pigment stones, as observed at the cholecystectomy, and liver fluke infestation seems involved in the pathogenesis of stone formation.

Gallstone composition: are children different?

During a 5-year period (1997-2002) 20 consecutive children (11 boys; median age, 8 years; range, 0.3-13.9 years) underwent cholecystectomy for cholelithiasis at a regional pediatric surgical center. Multiple stones were present in 16 patients (80%). All stones were collected prospectively. Composition studies were performed after grinding an aliquot of stone and examining a layer of crushed powder by Fourier transform infrared microspectroscopy. The relative proportions of each major stone component were assessed: cholesterol, protein and calcium salts of bilirubin, fatty acids, carbonate, and hydroxyapatite. Of the 20 children, 10 had black pigment stones, 2 had cholesterol stones, 1 had brown pigment stones, and 7 had calcium carbonate stones; the latter are exceptionally rare in adults. The composition of pediatric gallstones in this series differs from that found in adults.

Factors influencing the prevalence of gallstones in liver disease: the beneficial and harmful influences of alcohol

OBJECTIVE

The Patient Treatment File of the Department of Veterans Affairs comprises the computerized records of all inpatients treated in all Veterans Affairs hospitals distributed throughout the United States. This database was used to study the association between liver disease and clinically manifest cholelithiasis.

METHODS

The computerized medical records of 38,459 patients with various forms of liver disease and 69,336 controls without the diagnosis were extracted from the annual files between 1990 and 1993. In a multiple logistic regression analysis, the occurrence of cholelithiasis served as the outcome variable, whereas different forms of liver disease and demographic characteristics, such as age, gender, and ethnicity, served as predictor variables.

RESULTS

Among the control population, cholelithiasis was reported in 5.2% (3,571 of 69,336) of subjects. Cholelithiasis occurred in 7.5% (2,898 of 38,459) of patients with all liver disease, 9.5% (1,642 of 17,287) of patients with alcoholic liver cirrhosis, 13.7% (981 of 7,149) of patients with nonalcoholic liver cirrhosis, and 9.1% (66 of 728) of patients with alcoholic fatty liver (chi2 = 1059, df = 4, p < 0.001). In the logistic regression, the odds ratios (ORs) for cholelithiasis associated with various forms of liver disease were: in all liver diseases combined (OR = 1.31, 95% CI = 1.25-1.38), in alcoholic liver cirrhosis (OR = 1.62, 95% CI = 1.54-1.72), in nonalcoholic liver cirrhosis (OR = 2.07, 95% CI = 1.94-2.21), and in alcoholic fatty liver (OR = 1.40, 95% CI = 1.11-1.75). Other risk factors for cholelithiasis besides liver disease were: female gender (OR = 1.43, 95% CI = 1.25-1.63), older age (OR = 1.28 per age decade, 95% CI = 1.26-1.30), Native American (OR = 1.38, 95% CI = 1.12-1.72) or Hispanic ethnicity (OR = 1.25, 95% CI = 1.15-1.35), and presence of diabetes mellitus (OR = 1.43, 95% CI = 1.35-1.52). A history of alcoholism exerted a protective influence (OR = 0.92, 95% CI = 0.87-0.97).

CONCLUSION

Gallstone disease occurs frequently in hospitalized patients with chronic liver disease or liver cirrhosis and contributes to the burden of the disease.

Pancreatic and biliary disorders in the elderly

Structural and functional changes in the biliary tract and pancreas associated with advanced age are well documented in the literature and must be taken into account in evaluating patients with possible biliary and pancreatic disorders. The relationship between normal, age-related physiologic changes and various pancreatico-biliary diseases is not well defined. Elderly patients may present with severe biliary and pancreatic disease that may pose difficult management problems because of coexisting medical illnesses. Despite these challenges, all but the most frail elderly patients can benefit from appropriate medical, endoscopic, and surgical therapy.

Association of diabetes, serum insulin, and C-peptide with gallbladder disease

An inconsistent association has been found between gallbladder disease and diabetes mellitus. We hypothesized that insulin resistance rather than diabetes status may be a primary factor involved in gallstone formation. A total of 5,653 adult participants in the third United States National Health and Nutrition Examination Survey without known diabetes underwent gallbladder ultrasonography and phlebotomy after an overnight fast for measurement of serum insulin, C-peptide, and glucose. Gallbladder disease was defined as ultrasound-documented gallstones or evidence of cholecystectomy. Subjects were characterized as having normal fasting glucose (<110 mg/dL), impaired fasting glucose (110 to <126 mg/dL), or undiagnosed diabetes (>/=126 mg/dL). After controlling for other known gallbladder disease risk factors, among women, undiagnosed diabetes was associated with increased risk of gallbladder disease (prevalence ratio [PR] = 1.91, 95% confidence interval [CI] = 1.29-2. 83); whereas impaired fasting glucose was unassociated. Gallbladder disease risk in women increased with levels of fasting insulin (PR = 1.63, 95% CI = 1.11-2.40) and C-peptide (PR = 2.07, 95% CI = 1.32-3. 25) comparing highest to lowest quintiles. However, the association of gallbladder disease with undiagnosed diabetes was not diminished when the model included fasting insulin (PR = 1.85, 95% CI = 1.24-2. 77). In men, there was a statistically nonsignificant association with undiagnosed diabetes (PR = 2.11, 95% CI = 0.76-5.85), but no association of gallbladder disease with insulin or C-peptide. Among women higher fasting serum insulin levels increased the risk of gallbladder disease, but did not account for the increased risk in persons with diabetes.

Recreational physical activity and the risk of cholecystectomy in women

BACKGROUND

Physical activity may be an important determinant of the risk of gallstone disease in women, both independently and as a result of its role in maintaining body weight.

METHODS

We prospectively studied recreational physical activity (such as jogging, running, and bicycling) and sedentary behavior (such as spending hours watching television) in relation to the risk of cholecystectomy, a surrogate for symptomatic cholelithiasis, in a cohort of 60,290 women who were 40 to 65 years of age in 1986 and had no history of gallstone disease. As part of the Nurses' Health Study, the women reported on questionnaires mailed to them every two years both their activity level and whether they had undergone cholecystectomy. During a 10-year follow-up period (1986 to 1996), 3257 cases of cholecystectomy were documented.

RESULTS

Recreational physical activity was inversely related to the risk of cholecystectomy. The multivariate relative risk for women in the highest as compared with the lowest quintile of physical activity was 0.69 (95 percent confidence interval, 0.61 to 0.78). In contrast, sedentary behavior was independently related to an increased risk of cholecystectomy. As compared with women who spent less than 6 hours per week sitting while at work or driving, women who spent 41 to 60 hours per week sitting had a multivariate relative risk of 1.42 (95 percent confidence interval, 1.06 to 1.89), and women who spent more than 60 hours per week sitting while at work or driving had a multivariate relative risk of 2.32 (95 percent confidence interval, 1.26 to 4.26). These associations persisted after we controlled for body weight and weight change.

CONCLUSIONS

In women, recreational physical activity is associated with a decreased risk of cholecystectomy. The association is independent of other risk factors for gallstone disease, such as obesity and recent weight loss.

Prevalence and ethnic differences in gallbladder disease in the United States

BACKGROUND & AIMS

Gallbladder disease is one of the most common conditions in the United States, but its true prevalence is unknown. A national population-based survey was performed to determine the age, sex, and ethnic distribution of gallbladder disease in the United States.

METHODS

The third National Health and Nutrition Examination Survey (NHANES III) conducted gallbladder ultrasonography among a representative U.S. sample of more than 14, 000 persons. The diagnosis of gallbladder disease by detection of gallstones or cholecystectomy was made with excellent reproducibility.

RESULTS

An estimated 6.3 million men and 14.2 million women aged 20-74 years had gallbladder disease. Age-standardized prevalence was similar for non-Hispanic white (8. 6%) and Mexican American (8.9%) men, and both were higher than non-Hispanic black men (5.3%). These relationships persisted with multivariate adjustment. Among women, age-adjusted prevalence was highest for Mexican Americans (26.7%) followed by non-Hispanic whites (16.6%) and non-Hispanic blacks (13.9%). Among women, multivariate adjustment reduced the risk of gallbladder disease for both Mexican Americans and non-Hispanic blacks compared with non-Hispanic whites.

CONCLUSIONS

More than 20 million persons have gallbladder disease in the United States. Ethnic differences in gallbladder disease prevalence differed according to sex and were only partly explained by known risk factors.

Prevalence of gallstones in sonographic surveys worldwide

The use of diagnostic sonography allows determination of the prevalence of gallstones in a representative sample of the general population. The objective of this article is to review the reports of sonographically based studies of gallstone prevalence in the world literature. All available published epidemiologic studies on the prevalence of cholecystolithiasis as determined by diagnostic sonography are summarized. The sonographically based studies published to date confirm that there are significant regional differences in the prevalence of gallstones. Certain risk factors, notably age and heredity, are present worldwide.

Serum ascorbic acid and other correlates of gallbladder disease among US adults

OBJECTIVES

This study examined the correlates of clinical gallbladder disease among US adults and whether serum ascorbic acid levels are associated with a decreased prevalence of gallbladder disease.

METHODS

Cross-sectional analyses of data from the Second National Health and Nutrition Examination Survey were conducted.

RESULTS

A total of 384 women (8%) and 107 men (3%) reported a history of gallstone disease, and 347 women (7%) and 81 men (2%) reported a history of cholecystectomy. An inverted U-shaped relation was found between serum ascorbic acid level and clinical gallbladder disease among women but not among men.

CONCLUSIONS

Ascorbic acid, which affects the catabolism of cholesterol to bile acids and, in turn, the development of gallbladder disease in experimental animals, may reduce the risk of clinical gallbladder disease in humans.

Ascorbic acid supplement use and the prevalence of gallbladder disease. Heart & Estrogen-Progestin Replacement Study (HERS) Research Group

To investigate the relation of ascorbic acid supplement use to gallbladder disease and cholecystectomy, we conducted a cross-sectional analysis of baseline from 2744 postmenopausal women, aged 44-79 years, enrolled in the Heart & Estrogen-progestin Replacement Study (HERS), a secondary coronary heart disease prevention trial. A total of 629 HERS participants (23%) reported a history of gallbladder disease. Of these, 508 (19%) also reported a history of cholecystectomy. In bivariate models, ascorbic acid supplement use was associated with a decreased prevalence of gallbladder disease [odds ratio (OR)=0.74; 95% confidence interval (CI), 0.57, 0.96] and a trend toward a decreased prevalence of cholecystectomy (OR=0.77; 95% CI, 0.58, 1.02). Because we detected significant interactions between ascorbic acid supplement use and alcohol consumption, multivariate analyses were performed stratified by drinking status. After adjustment for potential confounding variables, use of ascorbic acid supplements among drinkers was associated with a decreased prevalence of gallbladder disease (adjusted OR=0.50; 95% CI, 0.31, 0.81) and cholecystectomy (adjusted OR=0.38; 95% CI, 0.21, 0.67). Use of ascorbic acid supplements among non-drinkers was not significantly associated with either prevalence of gallbladder disease or cholecystectomy. Further study is necessary to confirm our findings and, specifically, to examine the combined effects of ascorbic acid and alcohol on cholesterol metabolism.

Cholelithiasis in Taiwan. Gallstone characteristics, surgical incidence, bile lipid composition, and role of beta-glucuronidase

The nature and occurrence of gallstones in Taiwan and their etiologic factors might not be the same as in Western countries and warranted a systematic investigation. Gallbladder biles and gallstones were obtained at surgery from 100 and 74 patients, respectively. Common duct bile and stones were either drained through an indwelling common duct T-tube or aspirated through a nasobiliary catheter in 108 patients. Gallstones were analyzed for bilirubin, cholesterol, bile acid, calcium, and residue, and biles for bile acid, cholesterol, phospholipid, bilirubin, and beta-glucuronidase. There were four major kinds of gallstones in Taiwan: cholesterol/mixed stones, high-residue black formed pigment stones, low-residue brown formed pigment stones, and muddy pigment stones. The surgical incidence of all types of stones increased steadily during the past four decades. During the past 15 years the relative frequencies for mixed, formed pigment, and muddy pigment stones had been roughly 40, 40, and 20%, respectively, with a further increase in the mixed stones and a decrease in the muddy pigment stones in recent years. Improvement of nutritional status and living standards might contribute to such changes. Cholesterol content in the common duct and gallbladder biles was higher in the mixed stone group than in other groups. Bacterial beta-glucuronidase activity was detected in 53% of patients with muddy pigment stones. Endogenous beta-glucuronidase activity and concentration were also highest in this group, intermediate in the formed pigment and mixed stone group, and lowest in the control. We concluded that hypercholesterobilia was responsible for increasing incidence of mixed stones during the past two decades, while both bacterial and human beta-glucuronidase might contribute to pigment cholelithiasis.

Effect of acute bile acid pool depletion on total and ionized calcium concentrations in human bile

Although calcium salts are important components of gallstones, there are few data on the total and ionized calcium content of human bile. Therefore, in 14 fasting T-tube patients studied 7-11 days after cholecystectomy, we measured bile flow, bile acid [BA], total [CaTOT] and free ionized [Ca++] calcium concentrations, in 20-30 min bile collections during acute BA pool depletion induced by 6-8 h of continuous bile drainage. During washout of the BA pool there were parallel falls in bile flow, BA output and total calcium output (correlation coefficients ranging from 0.59 to 0.99; P < 0.02-0.001). In 12 of the 14 patients, [CaTOT] also fell (from 1.84 +/- 0.29 to 1.32 +/- 0.34 mmol L-1) in parallel with [BA] (from 34.0 +/- 14.0 to 8.2 +/- 8.0 mmol L-1; r = 0.75-0.98; P < 0.005). In contrast, biliary [Ca++] remained virtually unchanged. These data suggest that the BAs are linked to the bound, rather than to the free, ionized, fraction of biliary calcium, which is consistent with in vivo calcium binding by BAs. A model is proposed in which BA-induced biliary calcium secretion results from (i) bile acid-induced water flow via solvent drag; and (ii) calcium binding in the bile canaliculus by bile acids, which induces paracellular diffusion of Ca++, thereby maintaining [Ca++] independent of [BA].

Black pigment gallstones with cholesterol gallstones in the same gallbladder. 13 cases in a surgical series of 1226 patients with gallbladder stones

We studied 1312 consecutive patients who underwent surgery for gallstones in the biliary tract at one university hospital in Siena, Italy, with a systematic classification of gallstones found within the gallbladder. Of these patients, 1226 were found to have gallbladder stones; 94 of these had black pigment gallstones. Of these, 13 patients were found to have black pigment gallstones and cholesterol gallstones within their gallbladder. They all had multiple black pigment gallstones, usually very small (all < 6 mm diameter), in association with larger cholesterol stones in the gallbladder lumen. The cholesterol gallstones were single in seven cases, double in two cases, and multiple in four cases. All 13 of these patients with black pigment stones in association with cholesterol stones had histologic evidence of either adenomyomatosis or Rokitansky-Aschoff sinuses in the gallbladder wall. In nine of the 13 patients, the black pigment stones were located both in the gallbladder lumen and in close association with the gallbladder wall (in areas of adenomyomatosis or in Rokitanski-Aschoff sinuses). In the other four patients, the stones were found in close association with the gallbladder wall alone and not freely mobile within the gallbladder lumen. It is concluded that cholesterol stones and black pigment stones may be found in the same gallbladder. This association is infrequent with an incidence of 13 of 1226 (1.06%) in our series. There appears to be some relationship between the formation of the black pigment stones and the presence of adenomyomatosis or Rokitanski-Aschoff sinuses.(ABSTRACT TRUNCATED AT 250 WORDS)

Gallstone characteristics in Mexican Americans and non-Hispanic whites

Mexican Americans have an elevated risk of gallstones. Their increased rates may be due to genetic admixture with Native Americans, who have extremely high prevalences of cholelithiasis. Native Americans are believed to have almost exclusively cholesterol stones, whereas only 73% of non-Hispanics are reported to have such stones. Hence we hypothesized that Mexican Americans would have a higher proportion of cholesterol stones than would non-Hispanic whites. We interviewed 398 Mexican Americans and 93 non-Hispanic whites undergoing cholecystectomy and analyzed the composition of their gallstones. Mexican Americans were younger than non-Hispanic whites (P < 0.05). However, the age-sex standardized proportion of cholesterol stones was 89.7% in Mexican Americans and 87.2% in non-Hispanic whites. We conclude that Mexican Americans and non-Hispanic whites have gallstones of similar composition. The higher stone prevalence of Mexican Americans may be due to factors that predispose to both cholesterol and pigment stones.

Surgery in the elderly: observations on the pathophysiology and treatment of cholelithiasis

Biliary tract disease is particularly prevalent in older persons, and is the leading indication for acute abdominal surgery in the elderly. The complications of biliary stone disease are more insidious in the elderly, and the recognition of "symptomatic" disease is often delayed. The unreliable manifestations of biliary tract pathology result in a higher morbidity and mortality of the disease, and a large number of emergency operations. Recent studies suggest that the pathophysiology of cholelithiasis is specifically altered in the elderly. Pigmented gallstones, which are more common in the elderly, are thought to result from the action of bacterial enzymes that deconjugate bilirubin and form insoluble bile salts; bacterial contamination of the extrahepatic biliary system is more frequent in elderly patients. Gallbladder stasis may be due to age-related changes in the response of gallbladder musculature to the kinetic action of cholecystokin (CCK), possibly through a decrease in CCK receptor affinity or availability. Other hormonal factors which inhibit choleresis, such as pancreatic polypeptide, are increased with aging as well. Current efforts are being directed toward closer surveillance and discovery of cholelithiasis, and improved outcomes of therapy have been aided by the development of "minimally invasive" approaches to the treatment of cholelithiasis in the elderly.

Treatment of choledocholithiasis in patients with liver cirrhosis. Surgical treatment or endoscopic sphincterotomy?

OBJECTIVE

The clinical features of choledocholithiasis were analyzed in cirrhotic patients. The outcomes of surgical treatment and endoscopic sphincterotomy (EST) in this situation were compared and the risk factors predictive of an increased mortality rate were identified.

SUMMARY BACKGROUND DATA

In cirrhotic patients, high risk for gallbladder stones in cholecystectomy has been established. Common bile duct stones can often exacerbate liver dysfunction and might be more difficult to treat.

METHODS

Among 16 cirrhotic patients with choledocholithiasis, 9 underwent choledocholithotomy and T-tube placement (surgery group) and 7 underwent EST (EST group). Pretreatment clinical data were comparable between groups.

RESULTS

Among 16 patients, 15 had biliary tract symptoms and 7 had cholangitis. The surgery group had excessive intraoperative hemorrhage (1576 mL) and a high morbidity rate (66.7%). The mortality rate was 44.4%: 0% in Child A or B classification patients and 80% in Child C patients. The common causes of death were liver failure, postoperative hemorrhage, and sepsis. The EST group had no complications related to procedures, but there was one death (14.3%) due to preexisting liver failure. Hepatic dysfunction, coagulopathy, and cholangitis were factors predictive of an increased mortality rate.

CONCLUSIONS

Choledocholithiasis in cirrhotic patients should be treated by EST after liver function and general condition are improved by medical management, except in emergency cases.

Occult microlithiasis in 'idiopathic' acute pancreatitis: prevention of relapses by cholecystectomy or ursodeoxycholic acid therapy

Gallstone pancreatitis is usually related to small stones, which may not be detected by conventional cholecystographic techniques. In the current study, it was hypothesized that some patients with acute pancreatitis of unknown cause could harbor occult microstones in the gallbladder. Therefore, evidence was sought prospectively of missed gallstones by biliary drainage and microscopic examination of centrifuged duodenal bile in 51 patients recovering from an attack of acute pancreatitis, including 24 patients with relapsing episodes. Clusters of cholesterol monohydrate crystals, calcium bilirubinate granules, and/or CaCO3 microspheroliths were found in 67% of the patients. Biliary drainage showed no abnormal findings in 12 patients convalescing from a bout of known alcoholic pancreatitis. Examination of gallbladder bile at cholecystectomy and/or serial ultrasonography of the gallbladder for up to 12 months showed that 73% of the patients with unexplained pancreatitis had biliary sludge or microlithiasis; the prior finding of biliary crystal/solid markers predicted their existence with both a sensitivity and a specificity of 86% and a predictive value of 94%. The probability of harboring occult gallstones was also associated with age (P = 0.004), prior recurrent pancreatitis (P = 0.024), and altered liver function tests results during an index episode (P = 0.003). In 13 patients with cholesterol monohydrate crystals in bile, ursodeoxycholic acid (10 mg.kg-1.day-1) eliminated gallbladder microlithiasis within 3-6 months, and subsequent maintenance treatment with a daily dose of 300 mg prevented both gallstone recurrence and further attacks of pancreatitis over a mean follow-up period of 44 months. Cholecystectomy also prevented gallstone-associated relapses in 17 of 18 patients followed up for a mean postoperative period of 36 months. This study provides firm evidence showing that in most patients with idiopathic acute pancreatitis, the disease is related to microscopic gallstones, as evidenced by the follow-up development of macroscopic stones or sludge and by the prevention of relapses with either cholecystectomy or a cholelitholytic bile acid. Occult gallstones should be strongly suspected when acute pancreatitis of unknown cause occurs in a relapsing manner and in aged patients and when it is associated with altered liver function test results. Biliary microscopy and/or follow-up ultrasonography of the gallbladder provide a simple means of uncovering them to institute appropriate therapy and prevent further attacks.

Pathogenesis of gallstones

The many developments in nonoperative methods for the treatment of gallstone disease underscore the importance of understanding the pathogenesis of these stones. Elucidation of the factors responsible for nucleation of crystals and the mechanism by which it occurs would appear to be the challenge if we are to define the cascade of events that results in gallstone formation.

Gallstone dissolution

Many methods are available for gallstone dissolution, including oral bile salts; cholesterol solvents such as mono-octanoin or methyl tert-butyl either; and calcium or pigment solvents such as EDTA and polysorbate. Which of these approaches will be appropriate for an individual patient depends on the type of stones; whether they are in the gallbladder or the bile ducts; whether access to the biliary tree is available; the patient's age and general medical condition; and the availability of necessary expertise. In the US, both chenodeoxycholate and ursodeoxycholate are now available. Ursodeoxycholate is more expensive but appears to produce fewer side effects and may be more efficacious. These agents are most effective in thin women with small floating, radiolucent cholesterol stones in a functioning gallbladder. Only about half of the small subset of patients will experience partial or complete dissolution of stones within a year. Stone recurrence and the potential toxicity of long-term therapy are problems with this approach. Therefore, for most patients, cholecystectomy, either in the traditional fashion or using a laparoscopic approach (see article later in this issue by Gadacz et al), is the most cost-effective and perhaps the safest option. Intragallbladder instillation of methyl tert-butyl ether probably will be applicable only to a small subset of patients, and treatment is likely to be followed by a high recurrence rate. In patients with retained common duct cholesterol stones and access to the biliary tree, mono-octanoin therapy is advantageous in that it can be initiated as soon as cholangiography demonstrates no extravasation. In properly selected patients, a 90% success rate with this technique can be expected within 7 days.

Gallbladder stones classified by chemical analysis of cholesterol content. Frederiksberg, 1987-1988

Gallstones from 80 cholecystectomies and 81 autopsies were chemically analysed and showed a trend of decreasing cholesterol content with increasing age (p = 0.00009). The frequency of cholesterol stones (cholesterol content greater than 70%) was higher in operated women (81%) than in operated men (33%) (p = 0.0006) and in the total autopsy material (42%). The study supports the theory that the predominance of gallstone disease in women is an effect of the preponderance of cholesterol stones. The accuracy of estimates of cholesterol content of gallstones from the appearance of the cut surface was low. When the chemical analysis was used as a key, only one in three was correct. There was a tendency to underestimate cholesterol content.

Biliary lipid composition in monozygotic and dizygotic pairs of twins

The relative contribution of genetic factors to biliary and serum lipid composition was studied in 17 monozygotic and 18 dizygotic middle aged male pairs of twins. Cholesterol precursors, squalene and Methylated sterols which reflect the activity of cholesterol synthesis were also measured. Pairwise intraclass correlations were determined for monozygotic and dizygotic twin pairs and heritability estimates were calculated. Molar % of biliary cholesterol and percentage distribution of biliary cholic acid and particularly deoxycholic acid showed significant pairwise correlations within the monozygotic but not the dizygotic pairs. Similar correlations were found for total biliary methylsterols and of the methylsterol subfractions for the two methostenols but not for squalene, lanosterol and dimethylsterols. In serum, the precursor sterols, but not squalene, showed even higher pairwise correlations in the monozygotic twins than the corresponding precursors in bile. Molar per cent of bile acids and phospholipids and cholesterol saturation index were not correlated significantly in either twin pairs, but the pairwise correlations tended to be higher in the monozygotic than in the dizygotic pairs. Gall stones were found in seven monozygotic and three dizygotic subjects. Two monozygotic twin pairs were concordant for gall stones; all the dizygotic pairs were discordant. Overall, these data suggest that molar percentage of biliary cholesterol, bile acid composition, cholesterol synthesis, bile cholesterol saturation, and gall stone formation may be under a significant genetic control.

Dissolution of bile duct stones

Mono-octanoin can be used either alone or as an adjunct to other techniques to dissolve cholesterol bile duct stones. This solvent can be administered through an existing T tube, through the nasobiliary route, or percutaneously through the liver. Unlike basket extraction, which requires a mature T-tube sinus tract, mono-octanoin can be used immediately postoperatively or for home dissolution therapy. The endoscopic extraction of bile duct stones has a 1 percent mortality rate and a 5 to 7 percent complication rate. Special mixtures of mono-octanoin, bile acids, and ethylene diaminetetraacetic acid (EDTA) are being evaluated to dissolve pigment stones. The use of methyl tert-butyl ether is still experimental but very effective. To be most successful, mono-octanoin treatment must be used in properly selected patients.

Weight, diet, and the risk of symptomatic gallstones in middle-aged women

To assess the risk factors for symptomatic gallstones, 88,837 women in the Nurses' Health Study cohort (age range, 34 to 59 years) were followed for four years after completing a detailed questionnaire about food and alcohol intake in 1980. A total of 433 cholecystectomies and 179 cases of newly symptomatic, unremoved gallstones, diagnosed by ultrasonographic examination or x-ray films, were reported during the four-year follow-up. The age-adjusted relative risk for very obese women, who had a Quetelet index of relative weight (weight in kilograms divided by the square of the height in meters) of more than 32 kg per square meter, was 6.0 (95 percent confidence interval, 4.0 to 9.0), as compared with women whose relative weight was less than 20 kg per square meter. For slightly overweight women (relative weight, 24 to 24.9 kg per square meter), the relative risk was 1.7 (95 percent confidence interval, 1.1 to 2.7). Overall, we observed a roughly linear relation between relative weight and the risk of gallstones. Among the 59,306 women whose relative weight was less than 25 kg per square meter, a high energy intake (greater than 8200 J per day), as compared with a low energy intake (less than 4730 J per day), was associated with an increased incidence of symptomatic gallstones (relative risk, 2.1; 95 percent confidence interval, 1.4 to 3.3), and an alcohol intake of at least 5 g per day was associated with a decreased incidence as compared with abstention (relative risk, 0.6; 95 percent confidence interval, 0.4 to 0.8). Parity did not appear to be an important risk factor after an adjustment was made for relative weight. These data support a strong association between obesity and symptomatic gallstones and suggest that even moderate overweight may increase the risk.

The prevalence and incidence of cholecystolithiasis in patients with chronic liver diseases: a prospective study

To investigate the prevalence and incidence of cholecystolithiasis in hepatitis B surface antigen-positive chronic liver diseases, a prospective study using hepatobiliary ultrasonography was conducted in 933 "healthy" persons and four groups of HBsAg-positive patients: 226 asymptomatic carriers, 73 patients with chronic active hepatitis, 77 patients with early liver cirrhosis and 124 patients with advanced liver cirrhosis. Patients with hepatocellular carcinoma or alcoholism were excluded. The prevalences of cholecystolithiasis increased along with the increasing duration and severity of chronic liver diseases, with a significant linear trend (p less than 0.001). The prevalences of cholecystolithiasis in patients with liver cirrhosis (18.5% in males, 31.2% in females) were 4 to 5.5 times higher than that of the healthy population (p less than 0.005). In addition, the linear trend of increasing prevalence with increasing age in the healthy population was not observed in patients with chronic liver diseases. On the other hand, five of the 69 patients with early liver cirrhosis were found to develop cholecystolithiasis during a mean follow-up period of 32 months. The calculated annual incidence of cholecystolithiasis was 2.6%. The results suggest that chronic liver disease, particularly liver cirrhosis, is a risk factor for cholecystolithiasis.

Beta-glucuronidase activity in the bile of gallstone patients both with and without duodenal diverticula

Patients with juxtapapillary duodenal diverticula have an increased occurrence of calcium bilirubinate gallstones. One possible hypothesis to explain this observation is enzymatic deconjugation of bilirubin conjugates in the bile. Beta-glucuronidase of human or bacterial origin may lead to deconjugation of the bilirubin glucuronides in bile. This, in turn, may increase the amounts of unconjugated, water-insoluble bilirubin which can precipitate as calcium bilirubinate, the main component of brown pigment stones. In this study we compared gallstone patients with and without duodenal diverticula treated with endoscopic papillotomy. Increased occurrence of bacteria producing beta-glucuronidase (p less than 0.01) and increased activity of bacterial beta-glucuronidase (pH 7.0) in the bile itself (p less than 0.01) were found in patients with duodenal diverticula. When the activity of the enzyme at pH 4.5, the optimum of the human enzyme, was measured, no such difference was found. The results support the hypothesis of bacterial glucuronidase as an etiologic factor in pigment gallstone disease in patients with duodenal diverticula. The high activity of bacterial enzyme found in the bile in some patients without diverticula suggests bacteria as an etiologic factor, independent of the presence of diverticula.

Does low entry of cystic duct predispose to stones in the common bile duct?

Images

Role of duodenal bile crystal analysis in the investigation of 'idiopathic' pancreatitis

Duodenal bile crystal analysis for the detection of gallstones was assessed in 26 patients with acute pancreatitis of known aetiology (11 attributable to gallstones and 15 to alcohol) and in 37 patients without a history of acute pancreatitis (21 with gallstones and 16 without). The sensitivity was 64-67 per cent and the specificity was 94-100 per cent in these groups. Analysis of duodenal bile from 14 patients with 'idiopathic' pancreatitis revealed calcium bilirubinate crystals (but not cholesterol crystals) in 5 patients (36 per cent). Gallstones were confirmed at cholecystectomy in three of these patients and also in one other patient who had a gallstone on a 'late' ultrasound examination but was negative for crystals. Thus 29 per cent of the original 'idiopathic' group had gallstones confirmed. Gallstone analysis showed that pigment stones were present in 7 of 31 (23 per cent) non-pancreatitis controls compared with 9 of 13 (69 per cent) pancreatitis patients (P = 0.0048). These results suggest that duodenal bile crystal analysis (involving both calcium bilirubinate and cholesterol crystals) may be a useful technique for the investigation of patients with 'idiopathic' pancreatitis.

Sludge and stones in gallbladder after pregnancy. Prevalence and risk factors

The prevalence of sludge and stones in the gallbladder of 298 women in the immediate post-partum period was ultrasonographically assessed. We have investigated some risk factors for the development of sludge or stones in these patients and followed up most of these patients by ultrasonography to detect the presence of sludge and/or stones in the year following their discovery. We found sludge in 80 (26.2%) and gallstones in 16 (5.2%) of these patients. Age, obesity and months of oral contraceptive use were risk factors only for the presence of gallstones. After 1 year of follow-up only 2 out of 45 patients with sludge but 13 out of 15 patients with gallstones still had abnormal ultrasonographic findings.

Agents for gallstone dissolution

Numerous methods are presently available for gallstone dissolution, including oral bile salts; cholesterol solvents such as mono-octanoin and methyl tert-butyl ether; calcium or pigment solvents such as EDTA and polysorbate; mechanical extraction techniques through a T-tube tract or after endoscopic sphincterotomy; or fragmentation methods such as ultrasonography or electrohydraulic lithotripsy, lasers, and extracorporeal shock waves. Which, if any, of these methods will be appropriate for an individual patient depends on the type of stones, whether they are in the gallbladder or bile ducts, whether access to the biliary tree is available, the patient's age and general medical condition, and the availability of expert radiologists, endoscopists, and newer equipment. In the United States, the only available oral bile salt for cholesterol gallstone dissolution is chenodeoxycholate. Ursodeoxycholate, which is more rapid and less toxic, has not been approved by the Federal Drug Administration. These agents are most effective in thin women with small, floating, radiolucent cholesterol gallstones in a functioning gallbladder. Only about half of this small subset of patients, however, will experience partial or complete dissolution of stones in 6 to 12 months. Moreover, recurrence is very likely, and the potential toxicity of long-term therapy is unknown. Thus, for most patients, cholecystectomy remains the most cost-effective and, perhaps, safest option. Intragallbladder instillation of methyl tert-butyl ether and extracorporeal shock wave therapy are also likely to be applicable to only small subsets of patients and to be associated with high recurrence rates. In patients with retained ductal cholesterol stones and access to the biliary tree, mono-octanoin therapy is advantageous in that it can be begun as soon as cholangiography demonstrates no extravasation. In properly selected patients, a 90 percent success rate with mono-octanoin infusion can be expected within a week. Radiologic or endoscopic extraction techniques require maturation of a relatively straight T-tube tract but are not dependent on the type of stone. In the hands of experts, these techniques are highly successful. In postcholecystectomy patients without access to the biliary tree, endoscopic sphincterotomy has become the preferred method of management and can be expected to succeed in more than 90 percent of patients. At this point, the exact role for ultrasonic or electrohydraulic lithotripsy and lasers is unknown. However, these techniques may be applicable in the future in patients with retained bile duct stones in whom extraction and infusion techniques have failed.

An animal model of pigment cholelithiasis

Pigment stones of high calcium content were induced in male hamsters of the Harlan Sprague-Dawley strain fed a nutritionally adequate semipurified diet for a period of 14 weeks. The diet contained moderate amounts of cholesterol (0.30 percent) and ethinyl estradiol (15 micrograms/day per animal). At sacrifice, the incidence of pigment stones was 50 percent. When stones were present, they were in the form of numerous black amorphous rods about 0.1 to 0.4 mm in length. Infrared analysis of the dried stones indicated the following composition: calcium phosphate 26.7 percent, calcium bilirubinate 12.8 percent, cholesterol 15.1 percent, and protein 45.4 percent. Pigment stones were associated with an elevated biliary total calcium level (probably induced by the dietary cholesterol) and a paradoxic decrease in the biliary total bilirubin level. The lithogenic diet produced marked elevations in liver and plasma cholesterol levels and cholesterol saturation of bile, but no cholesterol crystals or stones were observed. The accumulation of elevated levels of cholesterol in the livers of the experimental animals produced mild to moderate hepatotoxicity. The precise mechanism of the dietary induction of pigment stones in this hamster model remains to be elucidated.

Human biliary beta-glucuronidase: correlation of its activity with deconjugation of bilirubin in the bile

Total and conjugated bilirubin contents of gall-bladder and hepatic biles before and after 24-h incubation at 37 degrees C and beta-glucuronidase activity of hepatic biles were determined in forty-eight patients divided equally into four groups: no stones or control (C), cholesterol stones (CS), black pigment stones (black PS), and brown pigment stones (brown PS). The percent conjugation of bilirubin is lower in gall-bladder biles and hepatic biles after incubation, particularly in black PS and brown PS, when compared with hepatic biles before incubation. Mean endogenous beta-glucuronidase activities at pH 5.2 were 12.0, 15.5, 44.5 and 147.7 nmol min-1 ml-1 for C, CS, black PS, and Brown PS, respectively, which correlated well with the degree of deconjugation of bilirubin in gall-bladder and hepatic biles and with the rate of deconjugation of hepatic bile incubated at 37 degrees C. Only four biles in brown PS exhibited bacterial enzyme activity. We concluded that though bacterial beta-glucuronidase might be responsible for deconjugation of bilirubin in some patients in brown PS, endogenous biliary beta-glucuronidase could play a key role in the pathogenesis of pigment cholelithiasis.

Cholesterol and pigment gallstones in northern India. A prospective analysis

Two hundred one consecutive patients with gallstone disease who had undergone cholecystectomy were analyzed to determine the relative frequency of occurrence of cholesterol and pigment gallstones and to identify distinguishing features of the two stone types. Cholesterol stones (CS) formed the majority (94%) of gallstones. There were no distinctive clinical, biochemical, or radiological features of CS or pigment stones (PS). However, CS were found significantly more often than PS (P less than 0.05) in multiparous women leading a sedentary life-style. Although multiplicity of gallstones was somewhat commoner with CS (P less than 0.05) and radiopacity with PS (P less than 0.05) as compared with the other stone type, these differences were certainly not discriminatory between CS and PS.