Epidemiological study on Korean gallstone disease: a nationwide cooperative study

Increased risk of gallstones after appendectomy: A longitudinal follow-up study using a national sample cohort

To evaluate the association between appendectomy and the occurrence of gallstones using a national sample cohort from Korea.The Korean National Health Insurance Service-National Sample Cohort was collected from 2002 to 2013. We extracted data for patients who had undergone appendectomy (n = 14,955) and a 1:4 matched control group (n = 59,820) and then analyzed the occurrence of gallstones. The patients were matched according to age, sex, income, region of residence, hypertension, diabetes mellitus, and history of dyslipidemia. Appendectomies were identified using operation codes (Q2860-Q2863) for appendicitis alone (International Classification of Disease-10: K35). Gallstones were diagnosed if the corresponding International Classification of Disease-10 code (K80) was reported ≥2 times. Crude (simple) and adjusted hazard ratios (HRs) were analyzed using stratified Cox proportional hazard models, and 95% confidence intervals were calculated. Subgroup analyses were performed based on age, sex, and time period after appendectomy.The adjusted HR for gallstones was 1.78 (95% confidence interval = 1.51-2.09, P < .001) in the appendectomy group. Consistent HRs were found in the analyses of all the subgroups determined using age and sex, with the exception of men ≥60 years of age. The risk of gallstones was increased during the first year after appendectomy.The occurrence of gallstones was increased in the patients who had undergone appendectomy.

A novel approach with holmium laser ablation for endoscopic management of intrahepatic biliary stricture

Background

Hepatolithiasis, featuring high incidence, severe symptoms, and common recurrence, poses a heavy disease burden. Endoscopic management provides an opportunity to cure hepatolithiasis, but fails to properly resolve biliary stricture without additional interventional techniques. An innovative approach towards endoscopic management of biliary stricture is required.

Methods

Holmium laser ablation was applied to biliary strictures via endoscopic access. Patients’ demographic, operative, and follow-up data after receiving holmium laser ablation were retrospectively collected for analysis.

Results

A total of 15 patients (4 males and 11 females) underwent stricture ablation by holmium laser via cholangioscopy. All the patients successfully received holmium laser ablation, indicating a technical success rate of 100%. No postoperative mortality or no major perioperative complication was observed. During the follow-up period, the recurrence-free rate was 73% at 2 years and 67% at 5 years.

Conclusions

We successfully developed a novel technique of biliary stricture removal by cholangioscopic holmium laser ablation with satisfying clinical outcomes.

Association between cholelithiasis and sialolithiasis: Two longitudinal follow-up studies

This study aimed to evaluate the association between cholelithiasis and sialolithiasis using a national sample cohort in Korea.The Korean National Health Insurance Service-National Sample Cohort (patients ≥20 years old) was collected from 2002 to 2013. In study I, we extracted cholelithiasis patients (n = 21,170) and 1:4 matched control I subjects (n = 84,680) and analyzed the occurrence of sialolithiasis. In study II, we extracted sialolithiasis patients (n = 761) and 1:4 matched control II subjects (n = 3044) and analyzed the occurrence of cholelithiasis. Hazard ratios (HRs) were determined using the stratified Cox proportional hazard model.The HR for sialolithiasis was 1.49 (95% CI = 0.88-2.52) in the cholelithiasis group (P = .14), and the HR for cholelithiasis was 1.18 (95% CI = 0.53-2.59) in the sialolithiasis group (P = .69).We did not find an association between cholelithiasis and sialolithiasis.

Bidirectional association between gallstones and renal stones: Two longitudinal follow-up studies using a national sample cohort

The present study evaluated the associations between gallstones and renal stones using a national sample cohort of the Korean population. The Korean National Health Insurance Service-National Sample Cohort was collected from 2002 to 2013. We designed two different longitudinal follow-up studies. In study I, we extracted gallstone patients (n = 20,711) and 1:4-matched control I subjects (n = 82,844) and analyzed the occurrence of renal stones. In study II, we extracted renal stone patients (n = 23,615) and 1:4-matched control II subjects (n = 94,460) and analyzed the occurrence of gallstones. Matching was performed for age, sex, income, region of residence, and history of hypertension, diabetes mellitus, and dyslipidemia. Crude and adjusted hazard ratios (HRs) were calculated using a Cox proportional hazards model, and the 95% confidence intervals (CIs) were calculated. Subgroup analyses were performed according to age and sex. The adjusted HR of renal stones was 1.93 (95% CI = 1.75–2.14) in the gallstone group (P < 0.001). The adjusted HR of gallstones was 1.97 (95% CI = 1.81–2.15) in the renal stone group (P < 0.001). The results were consistent in all subgroup analyses. Gallstones increased the risk of renal stones, and renal stones increased the risk of gallstones.

[Management of Intrahepatic Duct Stone]

Intrahepatic duct (IHD) stone is the presence of calculi within the intrahepatic bile duct specifically located proximal to the confluence of the left and right hepatic ducts. This stone is characterized by its intractable nature and frequent recurrence, requiring multiple therapeutic interventions. Without proper treatment, biliary strictures and retained stones can lead to repeated episodes of cholangitis, liver abscesses, secondary biliary cirrhosis, portal hypertension, and death from sepsis or hepatic failure. The ultimate treatment goals for IHD stones are complete removal of the stone, the correction of the associated strictures, and the prevention of recurrent cholangitis. A surgical resection can satisfy the goal of treatment for hepatolithiasis, i.e., complete removal of the IHD stones, stricture, and the risk of cholangiocarcinogenesis. On the other hand, in some cases, such as bilateral IHD stones, surgery alone cannot achieve these goals. Therefore, the optimal treatments require a multidisciplinary approach, including endoscopic and radiologic interventional procedures before and/or after surgery. Percutaneous transhepatic cholangioscopic lithotomy (PTCS-L) is particularly suited for patients at poor surgical risk or who refuse surgery and those with previous biliary surgery or stones distributed in multiple segments. PTCS-L is relatively safe and effective for the treatment of IHD stones, and complete stone clearance is mandatory to reduce the sequelae of IHD stones. An IHD stricture is the main factor contributing to incomplete clearance and stone recurrence. Long-term follow-up is required because of the overall high recurrence rate of IHD stones and the association with cholangiocarcinoma.

Bidirectional Association between Nonalcoholic Fatty Liver Disease and Gallstone Disease: A Cohort Study

Nonalcoholic fatty liver disease (NAFLD) and gallstone disease (GD) are often found to coexist but the sequential relationship of NAFLD and GD to each other remains controversial. We prospectively evaluated the bidirectional relationship of NAFLD with GD. A cohort study was performed on Korean adults who underwent a health checkup and were followed annually or biennially for a mean of 6.0 years. Fatty liver and gallstones were diagnosed by ultrasound. NAFLD was defined as hepatic steatosis on ultrasonography in the absence of excessive alcohol use or other identifiable causes. The NAFLD severity was determined by non-invasive fibrosis markers. Among 283,446 participants without either gallstones or cholecystectomy at baseline, 6440 participants developed gallstones. Among 219,641 participants without NAFLD at baseline, 49,301 participants developed NAFLD. The multivariable-adjusted hazard ratio (95% confidence interval) for incident gallstone comparing the NAFLD group vs. the non-NAFLD group was 1.26 (1.17–1.35). Increased non-invasive fibrosis markers of NAFLD were positively associated with an increased incidence of gallstones in a graded and dose-responsive manner (p-trend < 0.01). The multivariable-adjusted hazard ratios (95% confidence intervals) for incident NAFLD comparing gallstone and cholecystectomy to no GD were 1.14 (1.07–1.22) and 1.17 (1.03–1.33), respectively. This large-scale cohort study of young and middle-aged individuals demonstrated a bidirectional association between NAFLD and GD. NAFLD and its severity were independently associated with an increased incidence of gallstones, while GD and cholecystectomy were also associated with incident NAFLD. Our findings indicate that the conditions may affect each other, requiring further studies to elucidate the potential mechanisms underlying this association.

Association between Hashimoto's thyroiditis and cholelithiasis: a retrospective cohort study in Taiwan

OBJECTIVE

To investigate the relation of Hashimoto's thyroiditis (HT) to cholelithiasis and cholecystectomy in a retrospective population-based study.

SETTING

Cohort study.

PARTICIPANTS

We identified 1268 patients aged ≥20 years with HT between 2000 and 2010 as the study cohort.

PRIMARY AND SECONDARY OUTCOME MEASURES

Patients without HT were randomly selected from a database and propensity-matched with the study cohort at a 1:4 ratio according to age, sex, comorbidities and year of the index date to measure the incidence of cholelithiasis and cholecystectomy.

RESULTS

The cumulative incidence of cholelithiasis was higher in the HT cohort than that in the non-HT cohort (log-rank test, p<0.001), with a 1.91-fold higher risk of choleithiasis (95% CI 1.58 to 2.33) after adjustment for comorbidities. The age-specific relative risk of cholelithiasis in the HT cohort was higher than that in the non-HT cohort for patients aged ≥50 years (adjusted HR (aHR)=2.59, 95% CI 1.33 to 5.03). The sex-specific relative risk of cholelithiasis in the HT cohort was higher than that in the non-HT cohort for women (aHR=1.99, 95% CI 1.63 to 2.44). Compared with those in the non-HT cohort, patients with HT without (aHR=1.95, 95% CI 1.53 to 2.49) and with (aHR=1.94, 95% CI 1.51 to 2.49) thyroxine treatment were associated with a higher risk of cholelithiasis. Compared with those in the non-HT cohort, patients with HT had a higher risk of cholecystectomy (aHR=1.28, 95% CI 1.02 to 1.61).

CONCLUSIONS

Inability to obtain information on several potential confounding factors and misclassification of important covariates are the major limitations of the study. Our study indicates HT per se was associated with the development of cholelithiasis, which has been validated by the association between cholecystectomy and HT. Surveys and health education on cholelithiasis in women aged ≥50 years with HT should be considered by clinicians, and further prospective research should be done on this topic.

Association between diet and gallstones of cholesterol and pigment among patients with cholecystectomy: a case-control study in Korea

BACKGROUND

The prevalence of cholesterol gallstones is high in Western populations, while pigment gallstones are common in Asian populations. Dietary factors are suggested to be associated with gallstone risk, but their relationship with gallstone type has not been evaluated. This study investigated the association between diet and risk of cholesterol gallstone or pigment gallstone in a Korean population whose dietary pattern and type of gallstone were changed during the last 30 years.

METHODS

Patients with cholesterol (n = 40) and pigment (n = 59) gallstones were recruited after laparoscopic cholecystectomy and were compared with those of age- and sex-matched controls without gallstones (n = 99). Dietary intakes were assessed by trained dietitians using a semi-quantitative food frequency questionnaire. Multinomial logistic regression analysis was performed to calculate odds ratios and 95% confidence intervals to examine the associations between diet and risk for type of gallstones adjusted by potential confounders.

RESULTS

Patients with cholesterol gallstone consumed more lipid, animal lipid, beef, pork, and fried food than those with pigment gallstones and control, while patients with pigment gallstone consumed more carbohydrate and noodles than patients with cholesterol gallstone and control. In multinomial logistic regression analysis using control as reference group, dietary pattern with high consumption of beef, pork, and fried food was associated with risk of cholesterol gallstones, while there was no association between the risk of pigment gallstone and dietary pattern. In addition, control consumed more alcohol than patients with cholesterol and pigment gallstones.

CONCLUSIONS

The present study suggested consumption of fat from meat and fried foods increased the risk of cholesterol gallstone, and intake of carbohydrate from noodles increased the risk of pigment gallstone.

Gallstones and the Risk of Gallbladder Cancer Mortality: A Cohort Study

OBJECTIVES

Despite epidemiologic data, definitive evidence for the role of gallstones as a cause for gallbladder cancer is lacking. The goal of this study was to evaluate the association between gallstones, determined by ultrasound, and the risk of gallbladder cancer mortality in a large study of Korean men and women. In addition, the association between gallstones and cholecystectomy, and risk of hepatobiliary cancer mortality was investigated.

METHODS

A cohort study was performed for 396,720 South Korean men and women who underwent a health checkup from 2002 to 2012. Hazard ratios for mortality outcomes were estimated using Cox-proportional hazards regression analysis. Vital status and cause of death assignment were based on linkage to the National Death Index of death certificate records.

RESULTS

From a total of 2,158,906.2 person-years of follow-up (median follow-up of 5.4 years), we identified 224 deaths from hepatobiliary cancer, comprising 174 cases of liver/intrahepatic bile ducts cancer, 20 cases of gallbladder cancer, and 30 cases of biliary tract cancer. Gallstones were significantly associated with increased risk of hepatobiliary cancer mortality, especially liver/intrahepatic biliary cancer, and gallbladder cancer mortality. The multivariable-adjusted hazard ratios (95% confidence intervals) for hepatobiliary cancer, liver/intrahepatic biliary cancer, and gallbladder cancer mortality comparing subjects having gallstones with those without gallstone disease were 2.74 (1.83-4.10), 2.34 (1.45-3.77), and 7.35 (2.60-20.8), respectively. Cholecystectomy was not significantly associated with hepatobiliary cancer mortality.

CONCLUSIONS

In this large cohort study, gallstones were associated with increased risk of hepatobiliary cancer mortality, especially liver/intrahepatic cancer, and gallbladder cancer mortality independent of potential confounders. Future studies with longer follow-up periods that include data on incident cancer cases should provide a more comprehensive view of the role of gallstones in cancer development.

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

Background/Aims

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

Methods

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

Results

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

Conclusions

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

A nested case-control study on dietary fat consumption and the risk for gallstone disease

BACKGROUND

Gallstone disease (GD) incidence and prevalence rates differ between populations. Diet and lifestyle may be involved in GD development. To our knowledge, no study to date has evaluated quantitative data on diet when studying the relationship between fat consumption levels and GD in an Argentinean population. The present study aimed to assess the association between dietary fat intake and GD.

METHODS

A nested case-control study design was applied. Data were taken from subjects who participated in a previous cross-sectional study carried out in a random sample of asymptomatic people in Rosario, Argentina. Participants underwent a personal interview, and current weight and height, ancestor's ethnicity, and socio-economic status were recorded. Applying a food-frequency questionnaire and a food photography atlas, quantitative dietary data were estimated by combining the intake frequency, portion size and food composition. Logistic regression analysis was used to compute odds ratios and 95% confidence intervals adjusted by age, sex, ancestor's ethnicity, body mass index and daily total energy intake as potential confounders.

RESULTS

In total, 114 patients were studied (49 cases and 65 controls), without any statistically significant differences for age, sex, socio-economic status, body mass index and ancestry. The mean energy intake was higher in cases than in controls, and significant differences were found for dietary fat consumption. Obese or overweight people have a higher GD risk than subjects with normal weight. Increased GD risks were associated with high intakes of energy, total fat, and saturated and monounsaturated fatty acids.

CONCLUSIONS

According to our results, total fat, saturated and monounsaturated fatty acids high intakes are associated with increased GD risk.

Has the prevalence of cholesterol gallstones increased in Korea? A preliminary single-center experience

OBJECTIVES

We aimed to determine the prevalence of cholesterol gallstones, the compositional changes of gallstones and its predisposing factors in Korea with this single-center study.

METHODS

Data of 365 patients who underwent cholecystectomy for cholecystolithiasis from July 2008 to September 2011 were reviewed. Based on the compositional analysis of the gallstones, patients were assigned to either cholesterol gallstone group or pigment gallstone group. The characteristics of the patients and the gallstones were summarized and compared.

RESULTS

After eight patients with mixed gallstones were excluded, 357 patients were enrolled in the study, including cholesterol gallstones in 175 (49.0%) and pigment gallstones in 182 (51.0%). The number of patients with cholecystolithiasis increased but the prevalence of cholesterol gallstone decreased with age. Compared with the pigment gallstone group, the cholesterol gallstone group was associated with young age (<50 years), female gender, obesity (body mass index ≥ 25 kg/m²) and the absence of chronic liver diseases.

CONCLUSION

The relative prevalence of cholesterol gallstones in Korea has been stationary so far, but may change in the future since cholesterol gallstones are increasingly prevalent in the young generation.

Long-term follow-up study of gallbladder in situ after endoscopic common duct stone removal in Korean patients

BACKGROUND

Although there has been much debate over the fate of the gallbladder (GB) after endoscopic common bile duct (CBD) stone removal, subsequent cholecystectomy is generally recommended in patients with GB stones to prevent further biliary complications. The aims of this study were to assess the natural course of the patients with GB in situ after endoscopic CBD stone removal and to evaluate the necessity of prophylactic cholecystectomy.

METHODS

Four hundred sixty-one patients who had undergone CBD stone removal at Yeungnam University Hospital between January 2000 and December 2004 were retrospectively analyzed, and 232 patients were ultimately enrolled in this study.

RESULTS

The mean duration of follow-up was 73 (range = 7-126) months in the cholecystectomy group and 66 (6-127) months in the GB in situ group (p = 0.168). Ten patients (14.7 %) in the cholecystectomy group and 31 patients (18.9 %) in the GB in situ group developed recurrent CBD stones (p = 0.295). The highest percentage of recurrent CBD stones in both groups was that for brown stones (80 and 80.6 %). In the GB in situ group, cumulative recurrence rates of CBD stones were not significantly different between patients with GB stones and without GB stones (15.9 vs. 20 %, p = 0.798). However, the incidence of acute cholecystitis was significantly higher in patients with GB stones compared to patients without GB stones (13.6 vs. 2.5 %, p = 0.003).

CONCLUSIONS

Prophylactic cholecystectomy seems to be unnecessary in patients without GB stones after endoscopic sphincterotomy. However, in patients with GB stones, elective cholecystectomy or close observation is recommended due to the higher risk of cholecystitis.

Insulin resistance as a risk factor for gallbladder stone formation in Korean postmenopausal women

BACKGROUND/AIMS

The objective of this study was to determine whether insulin resistance is associated with gallbladder stone formation in Korean women based on menopausal status.

METHODS

The study included 4,125 consecutive Korean subjects (30-79 years of age). Subjects who had a medical history of diabetes, hypertension, dyslipidemia, other cardiovascular disorders, or hormone replacement therapy were excluded. The women were subdivided into two groups according to their menopausal status.

RESULTS

Analysis of premenopausal women showed no significant differences in the homeostasis model of assessment-insulin resistance (HOMA-IR) index between the two groups in terms of gallstone disease. The associations between the occurrence of gallbladder stones and age, obesity, abdominal obesity, hyperinsulinemia, and high HOMA-IR index were statistically significant in the analysis with postmenopausal women. In a multiple logistic regression analysis, low high density lipoprotein-cholesterol was an independent predictor of gallbladder stone formation in premenopausal women. However, the multiple logistic regression analysis also showed that age and HOMA-IR were significantly associated with gallbladder stone formation in postmenopausal women. In an additional analysis stratified by obesity, insulin resistance was a significant risk factor for gallbladder stone formation only in the abdominally obese premenopausal group.

CONCLUSIONS

Insulin resistance may be associated with gallbladder stone formation in Korean postmenopausal women with abdominal obesity.

The prevalence and risk factors for gallstone disease

Gallstone disease is one of the most prevalent gastrointestinal disorders. In addition, the costs associated with the diagnosis and treatment of gallstone disease have been rapidly increasing. The etiology and pathogenesis of gallstone disease remains incompletely understood. Gallstone formation may result from a complex interaction of genetic and environmental factors. This article reviews the prevalence and risk factors associated with gallstone disease. Understanding the pathogenesis of gallstone disease could lead to the development of better therapeutic and preventive strategies for dealing with this disease.

Recent trends in the distribution of common bile duct stones in urban South Koreans

This retrospective, observational study was designed to analyse recent trends in the age distribution of westernized persons in South Korea with common bile duct stones (cholesterol, brown and black stones). Data on 253 patients who had received endoscopic surgery at a tertiary referral hospital in Daegu, the third largest South Korean city, were used to investigate the relationship between the numbers of patients with different types of common bile duct stones and age. There were strong correlations between age and the frequency of the three different types of common bile duct stones. The frequency of cholesterol stones decreased exponentially with increasing patient age, whereas the frequency of brown stones increased exponentially. Patients with black stones showed a Gaussian-like age distribution. Thus, the age-dependency of the frequency of these three common types of bile duct stones differed from one another within this patient population.

Nationwide epidemiological study of severe gallstone disease in Taiwan

Background

Our study aimed to assess the nationwide trends in the incidence of severe gallstone disease in Taiwan among adults aged ≥20.

Methods

A retrospective longitudinal study was conducted using Taiwan National Health Insurance Research Database collected during 1997–2005. Patients with incident severe gallstone disease (acute cholecystitis, biliary pancreatitis, acute cholangitis) and gallstone-related procedures (elective and non-elective cholecystectomy, endoscopic retrograde cholangiopancreatography [ERCP]) that led to hospital admission were identified using ICD-9-CM diagnostic and procedure codes. Annual incidence rates of gallstone-related complications and procedures were calculated and their 95% confidence intervals (CI) were estimated assuming a Poisson distribution.

Results

The hospital admission rate for severe gallstone disease increased with advancing age and the age-standardized rate (95% CI) per 1000 population was 0.60 (0.59–0.60) for men and 0.59 (0.59–0.60) for women. Men had a higher rate of acute cholecystitis, probably due to the substantially lower rate of elective cholecystectomy among men than women. For those aged 20–39, hospital admissions for all gallstone-related complications and procedures increased significantly. For those aged ≥60, incidences of biliary pancreatitis, acute cholangitis, and hospital admission for gallstone receiving ERCP increased significantly without substantial change in the incidence of acute cholecystitis and despite a decreased rate of elective cholecystectomy.

Conclusion

This population-based study found a substantial increase in the rate of admission for severe gallstone disease among those aged 20–39. Concurrently, the incidences of biliary pancreatitis and acute cholangitis have risen among those aged ≥60.

Insulin resistance is associated with gallstones even in non-obese, non-diabetic Korean men

It remains unclear as to whether insulin resistance alone or in the presence of wellknown risk factors, such as diabetes or obesity, is associated with gallstones in men. The aim of this study was to determine whether insulin resistance is associated independently with gallstone disease in non-diabetic men, regardless of obesity. Study subjects were 19,503 Korean men, aged 30-69 yr, with fasting blood glucose level <126 mg/dL and without a documented history of diabetes. Gallbladder status was assessed via abdominal ultrasonography after overnight fast. Body mass index and waist circumference were measured. Insulin resistance was estimated by the Homeostasis Model Assessment of insulin resistance (HOMA-IR). The prevalence of obesity, abdominal obesity, and metabolic syndrome in the subjects with gallstones were higher than in those without. The prevalence of elevated HOMA (>75 percentile) in subjects with gallstones was significantly higher than in those without, and this association remained even after the obesity stratification was applied. In multiple logistic regression analyses, only age and HOMA proved to be independent predictors of gallstones. Insulin resistance was positively associated with gallstones in non-diabetic Korean men, and this occurred regardless of obesity. Gallstones appear to be a marker for insulin resistance, even in non-diabetic, nonobese men.

Gallstone analysis using Fourier transform infrared spectroscopy (FT-IR)

BACKGROUND

Gallstone analysis is important in determining the possible etiology of stone formation and the pathophysiology of cholelithiasis. Physical analysis using Fourier transform infrared spectroscopy (FT-IR), compared to chemical analysis, requires minimal sample volume, shows uniform sensitivity and specificity for all components and provides quantitative results with greater reproducibility. We studied the characteristics and distribution of gallstones using FT-IR in addition to the risk factors for gallstone formation in Korean patients. A better understanding of the mechanism underlying stone formation may help prevent gallstone development.

METHODS

Physical analysis of gallstones in 490 patients who underwent cholecystectomy was carried out using the FT-IR system 2000 (Perkin-Elmer Co.) and Spectrum software (Perkin-Elmer Co.). Visual inspection of the size, color, consistency and surface of the stones was compared with the physical characteristics. Clinical, demographic and laboratory findings were evaluated and compared with the gallstone components.

RESULTS

The FT-IR evaluation showed that most gallstones were composed of a single component (84.1%); cholesterol was the most commonly observed element among the major components (50%, 245/490). Morphological classification according to color, consistency and surface was different from the FT-IR composition analysis. There were significant differences in the components based on age, obesity, education level and the presence of diabetes mellitus.

CONCLUSIONS

The results of this study show that physical analysis of gallstones with FT-IR provides important information on stone composition, distribution and risk factors. These study results will help improve our understanding of the pathophysiology of gallstone disease in the Korean population, where there is a high frequency of hepatobiliary disorders.

Determination of chemical composition of gall bladder stones: Basis for treatment strategies in patients from Yaounde, Cameroon

AIM: Gallstone disease is increasing in sub-saharan Africa (SSA). In the west, the majority of stones can be dissolved with bile salts, since the major component is cholesterol. This medical therapy is expensive and not readily accessible to poor populations of SSA. It was therefore necessary to analyze the chemical composition of biliary stones in a group of patients, so as to make the case for introducing bile salt therapy in SSA.

METHODS: All patients with symptomatic gallstones were recruited in the study. All stones removed during cholecystectomy were sent to Houston for x-ray diffraction analysis. Data on age, sex, serum cholesterol, and the percentage by weight of cholesterol, calcium carbonate, and amorphous material in each stone was entered into a pre-established proforma. Frequencies of the major components of the stones were determined.

RESULTS: Sixteen women and ten men aged between 27 and 73 (mean 44.9) years provided stones for the study. The majority of patients (65.38%) had stones with less than 25% of cholesterol. Amorphous material made up more than 50% and 100% of stones from 16 (61.53%) and 9 (34.61%) patients respectively.

CONCLUSION: Cholesterol is present in small amounts in a minority of gallstones in Yaounde. Dissolution of gallstones with bile salts is unlikely to be successful.

Structural analysis of gallstones with thin-section petrographic microscopy: a study of 100 gallstones from Taiwanese patients

Cholecystolithiasis is a common disease, making cholecystectomy a commonly performed surgical procedure. The gross appearance of gallstones differs from case to case. To classify gallstones on the basis of their structure, we randomly collected gallstones from 100 (64 of them women) of 3,289 patients who underwent cholecystectomy at our hospital. The stones were grossly classified into five major types: pure-cholesterol stones, combination stones, mixed stones, black stones, and calcium bilirubinate stones. We then used thin-section petrographic microscopic study (TSPMS) to inspect each stone under a polarizing microscope. Final classification of the stone depended on TSPMS findings. Of the 100 patients, 35 had pure-cholesterol stones, 12 had combination stones, 17 had mixed stones, 25 had black stones, and 8 had calcium bilirubinate stones; the stones from 3 patients could not be classified on TSPMS. Accurate structural classification of gallstones could be made by gross inspection with confirmation by TSPMS, a useful method of classifying gallstones.

Characterization of primary pure cholesterol hepatolithiasis: cholangioscopic and selective cholangiographic findings

BACKGROUND

Primary pure cholesterol hepatolithiasis has been described recently. The aim of this study was to analyze its clinical and radiologic features, focusing on the cholangioscopic and selective cholangiographic findings.

METHODS

Primary pure cholesterol hepatolithiasis was identified in 3% (6 of 172) of patients who were treated with cholangioscopic stone removal for primary hepatolithiasis during the study period from 1995 to 1999. These 6 consecutive patients (M/F 5:1, mean age 40 years) were enrolled in the study. They underwent abdominal US, CT, endoscopic retrograde cholangiography (ERC), and percutaneous transhepatic cholangioscopy (PTCS). After confirming that the stones were of the cholesterol type, cholangioscopic stone removal via the percutaneous transhepatic route was performed. For the prevention of recurrence, ursodeoxycholic acid (10 mg/kg/day) was prescribed during follow-up.

RESULTS

US demonstrated high echogenicity with strong shadowing in dilated peripheral ducts, whereas CT failed to demonstrate any intraductal abnormal density or calcification except localized duct dilatation. PTCS demonstrated multiple, white to yellowish stones that were morphologically readily distinguishable from brown pigment intrahepatic stones. In all patients, selective cholangiography disclosed the ductal abnormalities, which could not be delineated by ERC in 4 patients. Complete stone removal by PTCS was achieved in 5 of 6 patients. During follow-up (12 to 49 months, mean 22 months), they were asymptomatic and stone recurrence was not detected by US.

CONCLUSIONS

Primary pure cholesterol hepatolithiasis is distinguishable from the more common brown pigment hepatolithiasis by its cholangioscopic and selective cholangiographic characteristics.

Percutaneous transhepatic cholangioscopic treatment for hepatolithiasis: an evaluation of long-term results and risk factors for recurrence

BACKGROUND

Percutaneous transhepatic cholangioscopy (PTCS) has a major role in the treatment of hepatolithiasis. The aims of this study were to evaluate immediate and long-term results of PTCS treatment and to elucidate the risk factors for recurrence of stones or cholangitis.

METHODS

A retrospective study was conducted of patients with hepatolithiasis who underwent PTCS treatment. A total of 92 patients underwent PTCS treatment and 68 were followed for 24 to 60 months (median 42 months).

RESULTS

Complete clearance of stones was achieved in 74 (80%) patients. The rate of complete clearance was significantly lower in patients with severe intrahepatic strictures compared with that for those with no strictures (14 of 24, 58% vs. 16 of 16, 100%, p < 0.01) and those with mild to moderate strictures (14 of 24, 58% vs. 44 of 52, 85%, p < 0.05). Patients with severe intrahepatic strictures had a higher recurrence rate than those with no or mild strictures (100% vs. 28%, p < 0.01). In addition the recurrence rate in patients with advanced biliary cirrhosis (Child's class B or C) was higher than in those with no or mild (Child's class A) cirrhosis (89% vs. 29%, p < 0.01). In patients with type I and II hepatolithiasis (Tsunoda classification), stones recurred in 2 (12%) patients at 28 and 32 months after successful stone removal, without further recurrence afterwards. The recurrence rate in patients with type III and IV hepatolithiasis increased gradually up to 50% at 60 months of follow-up.

CONCLUSIONS

Severe intrahepatic stricture was the only factor that affected the immediate success rate of PTCS in the treatment of hepatolithiasis. Several risk factors including severe biliary stricture, advanced biliary cirrhosis and Tsunoda type III and IV affected the long-term results.

Gallstones

At the turn of the millennium, significant advances continue to be made into the epidemiology and pathophysiology of gallstone disease. The NHANES III study, the largest American population-based study of gallstone disease, estimated that more than 20 million Americans have undergone gallbladder surgery or currently have gallstones. Insulin resistance may be an independent risk factor for gallstone disease.Cholecystokinin receptors may be responsible for the altered motility of the gallbladder smooth muscle, and mucin may play an underestimated role as a pronucleating factor. For the first time, researchers have been able to directly observe cholesterol crystallization in human bile. Improved understanding of the multiple factors involved in the pathogenesis of gallstone disease should lead to new therapeutic and preventive strategies.