Sludge is calcium bilirubinate associated with bile stasis

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.

Spontaneous rupture of the gall bladder: an unusual forensic diagnosis

Peritonitis secondary to spontaneous rupture/perforation of the gall bladder is a rare condition overall and is even less common in the forensic population. We report the case of a middle-aged man who died from generalized peritonitis from gall bladder perforation due to acute acalculous cholecystitis. This condition usually occurs in critical patients with systemic illness, and although the exact pathogenesis remains unclear, the development of acalculous cholecystitis appears to be multifactorial. Antemortem diagnosis is reliant upon clinical presentation, laboratory data, and radiologic studies. Surgery and appropriate antibiotics are mainstays of treatment; however, there is an emerging role for minimally invasive procedures. Histopathologic features show significant overlap with the calculous type. Although increasing numbers of acalculous cholecystitis have been diagnosed in the critically ill, the fatal presentation of a perforated gall bladder following an undiagnosed case of acute acalculous cholecystitis is unusual in a nonhospitalized and ambulatory man.

Endoscopic ultrasonography in patients with elevated carbohydrate antigen 19-9 of obscure origin

AIM: To evaluate the efficacy of endoscopic ultrasonography (EUS) in patients with elevated carbohydrate antigen (CA) 19-9 levels of obscure origin.

METHODS: Patients who had visited Pusan National University Hospital because of elevated serum CA 19-9 levels, between January 2007 and December 2009, were retrospectively enrolled. EUS had been performed on all subjects, in addition to routine blood tests, endoscopy, abdominal computed tomography (CT) and other clinical exams, which had not revealed any abnormal findings suggestive of the origin of the elevated CA 19-9 levels.

RESULTS: Of the 17 patients, gallbladder sludge was detected in 16 patients (94.1%) and common bile duct sludge was observed in 3 patients (17.6%). After the administration of ursodeoxycholic acid to 12 of the patients with gallbladder sludge, CA 19-9 levels normalized in 6 of the patients after a median of 4.5 mo.

CONCLUSION: EUS is a useful diagnostic method for patients with elevated CA 19-9 levels of obscure origin, even if the reason for abnormal levels of this serum marker cannot be determined through prior examinations, including abdominal CT.

Ultrasonographic Findings of Feline Cholangitis

Cholangitis is a common inflammatory disorder of the biliary system in cats. There are two major forms based on the predominate type of inflammatory cell infiltrates: lymphocytic or neutrophilic. Ultrasound is a common imaging modality used in these patients. This retrospective study evaluated the ultrasound examinations of 26 cats with a histologic diagnosis of cholangitis. Most cats with cholangitis had sonographically normal liver size, echogenicity, and normal biliary systems. Statistically significant sonographic changes for cats with cholangitis included hyperechoic liver parenchyma, hyperechoic gallbladder contents, and increased pancreatic size. No statistically significant changes were noted to distinguish lymphocytic and neutrophilic forms of cholangitis. Cats with the sonographic features of diffuse liver hyperechogenicity, gallbladder contents and enlarged pancreas may suggest cholangitis.

Choledocholithiasis in a 4-month-old infant

Cholelithiasis is increasingly being diagnosed in newborns and infants because of the more frequent use of abdominal ultrasound. However, common bile duct stones causing obstruction or symptoms in infancy are exceedingly rare and are not often reported in the literature. We report the successful treatment of symptomatic choledocholithiasis in a 4-month-old patient with endoscopic retrograde cholangiopancreatography and endoscopic sphincterotomy.

The clinical significance of bile duct sludge: is it different from bile duct stones?

BACKGROUND

Some patients with suspected common bile duct (CBD) stones are found to have sludge and no stones. Although sludge in the gallbladder is a precursor of gallbladder stones, the significance of bile duct sludge (BDS) is poorly defined. This study aimed to compare BDS with bile duct stones in terms of frequency, associated risk factors, and clinical outcome after endoscopic therapy.

METHODS

The study enrolled 228 patients who underwent therapeutic endoscopic retrograde cholangiopancreatography (ERCP) for suspected choledocholithiasis. The patients were divided into two groups: patients with BDS but no stones on ERCP and patients with CBD stones. The presence of risk factors for bile duct stones (age, periampullary diverticulum, ductal dilation or angulation, previous open cholecystectomy) were assessed at ERCP. Follow-up data (36 +/- 19 months) were obtained from medical records and by patient questioning.

RESULTS

Bile duct sludge occurred in 14% (31/228) of patients and was more common in females. After endoscopic clearance, CBD stones recurred in 17% (33/197) of the patients with CBD stones, and in 16% (5/31) of the patients with BDS (p = 0.99). Common bile duct dilation was less common in the sludge group. The other known risk factors for recurrent CBD stones (age, previous open cholecystectomy, bile duct angulation, and the presence of a peripampullary diverticulum) were not statistically different between the two groups.

CONCLUSIONS

The findings indicate that the clinical significance of symptomatic BDS is similar to that of CBD stones. Bile duct sludge seems to be an early stage of choledocholithiasis.

Gallstone disease: Microlithiasis and sludge

'Sludge' is the solid material which results from the slow settling of particles dispersed in a liquid medium. Biliary sludge in the gallbladder can be detected by transabdominal ultrasonography, and the typical echoes derive mainly from pigment precipitates mixed with cholesterol crystals. A portion of biliary sludge contains comparatively large particles (1-3 mm) called microliths, the formation of which is an obligatory intermediate step in the development of all types of gallstone. Microlithiasis and sludge in bile may cause colicky pain, cholecystitis, cholangitis, and acute pancreatitis, and are thus of clinical relevance. In these patients treatment follows the guidelines of symptomatic gallstone disease, and strategies include long-term application of ursodeoxycholic acid, endoscopic papillotomy, or preferably laparoscopic cholecystectomy.

Sludge ball, pseudolithiasis, cholelithiasis and choledocholithiasis from intrauterine life to 2 years: a 13-year follow-up

OBJECTIVE

Evaluation and follow-up of infants with cholelithiasis and pseudolithiasis in a pediatric ward.

PATIENTS & METHODS

Prospective study from April 1990 to October 2003 identified hospitalized infants younger than 2 years with ultrasonographic findings of cholelithiasis, choledocholithiasis or pseudolithiasis. Associated abnormalities or contributory factors were recorded and patients were followed for from 6 months to 13 years (mean, 4 years).

RESULTS

Thirty-four patients were diagnosed between the age of 3 weeks and 24 months. Thirteen (38%) had been treated with third-generation cephalosporins. Other associated factors were dehydration in 10 (29%), urinary tract infection in two (6%) and one each for cholestatic liver disease, total parenteral nutrition, immunoglobulin A deficiency and prematurity. Six infants (17%) had no known risk factor. Six additional patients were diagnosed by antenatal ultrasound.

CONCLUSIONS

Cholelithiasis in infants hospitalized for a variety of common pediatric conditions is not rare. Dehydration and treatment with third-generation cephalosporins are important associated factors. The classic risk factors of hemolysis and previous gastrointestinal surgery, were not found in our group. The overall prognosis was good. Pseudolithiasis disappeared in all infants. Of the 21 infants with cholelithiasis, only two developed cholecystitis. In nine infants, spontaneous resolution occurred. In the absence of other clinical or imaging evidence of biliary tract disease, conservative management is advised.

Sincalide in Patients with Parenteral Nutrition—Associated Gallbladder Disease

OBJECTIVE

To review the role of sincalide in treating and preventing parenteral nutrition (PN)–associated gallbladder disease.

DATA SOURCES

A MEDLINE (1996–March 2004) search was performed using the key terms cholecystokinin, sincalide, parenteral nutrition, cholelithiasis, cholestasis, and sludge.

DATA SYNTHESIS

Five human studies investigated the safety and efficacy of sincalide in patients with PN-associated gallbladder disease. Sincalide at intravenous doses of 0.04 μg/kg 3 times daily increased bile flow and improved serum bilirubin levels. However, patients with advanced liver disease did not respond to sincalide therapy. Long-term follow-up data on sincalide effects on liver disease progression are not yet available.

CONCLUSIONS

Sincalide improved the signs of cholestasis. However, its long-term effects in preventing and treating PN-associated gallbladder disease remain unknown and its routine use for this indication cannot be recommended at this time.

Hepatobiliary ultrasound

The use of ultrasound technology in the emergency department(ED) is a recent and fast-growing phenomenon. Ultrasound is an extremely valuable tool for the evaluation of gallbladder (GB) dis-ease in the ED for several reasons: this disease is a common medical problem, cholecystitis can present in different ways clinically,the nature of the GB allows it to be well visualized by ultrasound,and ultrasound has many benefits and few complications associated with its use. This article reviews the focused examination of the GB, with specific attention to test characteristics (sensitivity,specificity, positive predictive value, and negative predictive value)when performed by emergency physicians in the ED.

Approach to idiopathic recurrent pancreatitis

Acute pancreatitis is caused by acute or chronic alcohol intake or choledocholithiasis in approximately 80% of cases. In the absence of alcohol abuse or gallstones, a variety of established and putative factors must be considered, any of which can cause a single or recurrent attacks of acute pancreatitis. When the underlying cause eludes detection following an initial thorough search and leads to a second attack, the term idiopathic acute recurrent pancreatitis (IARP) is applied. This article discusses IARP and its work-up.

Idiopathic acute pancreatitis

After routine investigations, including a thorough history, routine laboratory study, and noninvasive imaging with transcutaneous ultrasonogram, 10% to 25% of cases of acute pancreatitis have no readily identifiable cause and are termed idiopathic. But modern medicine has made notable advances in uncovering various causes of acute pancreatitis, and several new diagnostic tools that allow clinicians to less invasively approach the patient without sacrificing the diagnostic yield have been introduced. By being knowledgeable of these new changes and by their proper use in a proper circumstances, clinicians will be able to find the cause more accurately and earlier. This better management will not only improve the well-being of the patients but also reduce the number of "true" idiopathic acute pancreatitis to a minimum.

Unconjugated bilirubin in human bile: the nucleating factor in cholesterol cholelithiasis?

AIMS

To investigate the concentrations of bilirubin, bilirubin conjugates, phospholipid, and cholesterol in the gall bladder bile obtained at surgery from patients with and without cholesterol gallstones.

METHODS

Gall bladder bile was collected during surgery, by puncture, from 20 patients with gallstones undergoing routine cholecystectomy and from eight patients with normal liver blood tests. Concentrations of bilirubin, bilirubin conjugates, phospholipid, and cholesterol were measured using standard procedures.

RESULTS

The proportion of total bilirubin that was unconjugated was significantly higher in the bile from patients with stones than in bile from control patients, whether or not the bile from either group was saturated with cholesterol or not. Indeed, the mean concentration of cholesterol was significantly higher in control bile samples.

CONCLUSION

The presence of stones was more closely related to the proportion of unconjugated bilirubin than to the degree of saturation of bile with cholesterol. Bilirubin and its metabolites probably play an important part in the formation of cholesterol gallstones.

Biliary sludge: the sluggish gallbladder

Biliary sludge is a mixture of particulate matter which has precipitated from bile. It generally consists of cholesterol monohydrate crystals, calcium bilirubinate or other calcium salts. In a clinical setting, biliary sludge is almost always an ultrasonographic diagnosis. Although it is less clinically applicable, direct microscopic examination of gallbladder bile is far more sensitive than ultrasonography into sludge detection, and has to be regarded as the diagnostic gold standard. The overall prevalence of sludge in the general population is relatively low. However, several clinical conditions are associated with a particularly high prevalence of biliary sludge, including pregnancy, rapid weight loss, total parenteral nutrition, octreotide therapy, bone marrow or solid organ transplantation. The clinical course of biliary sludge varies, and complete resolution, a waxing and waning course, and progression to gallstones are all possible outcomes. It may cause complications usually associated with gallstones, such as biliary colic, acute cholecystitis, and acute pancreatitis. The main pathogenic mechanism involved in sludge formation is probably gallbladder dismotility, and in selected patients measures aimed to maintain adequate gallbladder contractions has been shown to effectively prevent sludge development.

Gastrointestinal disorders of the critically ill. Biliary sludge and cholecystitis

Biliary sludge develops commonly in critically ill patients and may be associated with biliary colic, acute pancreatitis or acute cholecystitis. Sludge often resolves upon resolution of the underlying pathogenetic factor. It is generally diagnosed on sonography. Treatment of sludge itself is unnecessary unless further complications develop. Acute acalculous cholecystitis also develops frequently in critically ill patients. It may be difficult to diagnose in these patients, manifesting only as unexplained fever, leukocytosis or sepsis. Sonography and hepatobiliary scintigraphy are the most useful diagnostic tests. Management decisions should take into account the underlying co-morbid conditions. For many patients, percutaneous cholecystostomy may be the best management option. Cholecystostomy may also provide definitive drainage as patients recover and underlying critical illness resolves.

Second harmonic imaging improves trans-abdominal ultrasound detection of biliary sludge in 'idiopathic' pancreatitis

BACKGROUND

Recently, biliary sludge has been strongly correlated with 'idiopathic pancreatitis'. It is often diagnosed by trans-abdominal ultrasonography, despite the low sensitivity of this investigation. New scanners, using second harmonic imaging, may improve the quality of the echographic picture.

AIM

To verify the impact of this methodology on the detection of biliary sludge in patients with 'idiopathic' pancreatitis.

METHODS

Fifty patients with 'idiopathic' pancreatitis observed over a 18-month period entered the study. Exclusion criteria were gall-bladder stones, polyps, clinical conditions related to biliary sludge development and haemolytic disorders. Patients were assessed blind by two operators using either conventional ultrasonography or second harmonic imaging. The parameters of diagnostic quality of both examinations were evaluated using, as the gold standard, microscopic examination of the gall-bladder content collected at endoscopy after cholecystokinin infusion.

RESULTS

An improvement in sensitivity, specificity, efficiency and negative predictive value was obtained by second harmonic imaging compared with conventional ultrasonography.

CONCLUSIONS

Second harmonic imaging, in our experience, is a reliable non-invasive tool for the diagnosis and follow-up of biliary sludge in the course of 'idiopathic' pancreatitis.

Pathways of cholesterol crystallization in model bile and native bile

Hypersecretion of hepatic cholesterol, chronic supersaturation of bile with cholesterol and rapid precipitation of cholesterol crystals in the gallbladder from cholesterol-enriched vesicles represent the primum movens in cholesterol gallstone formation. Physical-chemical factors and pathways leading to cholesterol crystallization can be investigated in artificial model biles and ex vivo in fresh human bile. Depending on modulatory factors (i.e., lipid concentration, bile salt or phospholipid species, humidity, mucins, etc.), cholesterol can precipitate in several forms (i.e., monohydrate, anhydrous) and habits (i.e., plate-like, needle-like, intermediate arcs, filaments, tubules, spirals). Careful analysis of biliary cholesterol crystals includes biochemical analysis of precipitated crystals, polarizing quantitative light microscopy, and turbidimetric methods. In this paper, recent concepts on cholesterol crystallization in artificial model biles as well as in human bile will be reviewed.

The frequency of bile duct crystals in patients with presumed biliary pancreatitis

BACKGROUND

Previous studies of biliary microlithiasis in acute pancreatitis of uncertain etiology were conducted a few weeks to months after the acute episode. Bile obtained during urgent ERCP (less than 24 hours after admission) was studied for the presence of microlithiasis during the acute phase of acute pancreatitis of suspected biliary origin.

METHODS

Fifteen consecutive patients with acute pancreatitis of suspected biliary origin were recruited from a population of 309 patients with acute pancreatitis (5%) treated during the last 4 years. Patients with gallstones on US and/or ERCP and those in whom the etiology of acute pancreatitis was certain were excluded.

RESULTS

Microlithiasis (mostly calcium bilirubinate granules) was found in 12 (80%) cases. Despite endoscopic sphincterotomy 3 patients died within 2 weeks because of multisystemic organ failure. Among the 12 remaining patients, 2 (16%) developed gallbladder stones and 1 underwent cholecystectomy for cholecystitis (8%) during follow-up. The average length of follow-up was 30 months. No episodes of acute pancreatitis were noted during follow-up.

CONCLUSIONS

In the acute phase of acute pancreatitis of suspected biliary origin, biliary microlithiasis was found in most cases. Endoscopic sphincterotomy appears to protect patients from further episodes of acute pancreatitis.

Complications of long-term home total parenteral nutrition: their identification, prevention and treatment

The purpose of this review is to describe the most common complications of home total parenteral nutrition, their identification, treatment and prevention. Data sources were manuscripts and abstracts published in the English literature since 1968. Studies were selected for summarization in this review on the basis of clinical relevance to the practicing clinician. Home total parenteral nutrition is a relatively safe, life-saving method for nutrient delivery in patients with compromised gastrointestinal function. However, numerous complications, with associated morbidity and mortality, involving the delivery system and the gastrointestinal, renal, and skeletal systems may develop. Catheter-related complications are often preventable and treatable when they occur, although renal and bone abnormalities have elusive etiologies.

Gallbladder sludge: what is its clinical significance?

Biliary sludge is a mixture of particulate solids that have precipitated from bile. Such sediment consists of cholesterol crystals, calcium bilirubinate pigment, and other calcium salts. Sludge is usually detected on transabdominal ultrasonography. Microscopy of aspirated bile and endoscopic ultrasonography are far more sensitive. Biliary sludge is associated with pregnancy; with rapid weight loss, particularly in the obese; with critical illness involving low or absent oral intake and the use of total parenteral nutrition (TPN); and following gastric surgery. It is also associated with biliary stones with common bile duct obstruction; with certain drugs, such as ceftriaxone and octreotide; and with bone marrow or solid organ transplantation. The clinical course of biliary sludge varies. It often vanishes, particularly if the causative event disappears; other cases wax and wane, and some go on to gallstones. Complications caused by biliary sludge include biliary colic, acute cholangitis, and acute pancreatitis. Asymptomatic patients with sludge or microlithiasis require no therapy. When patients are symptomatic or if complications arise, cholecystectomy is indicated. For the elderly or those at risk from the surgery, endoscopic sphincterotomy can prevent recurrent episodes of pancreatitis. Medical therapy is limited, although some approaches may show promise in the future.

Gallstone formation. Local factors

Bile supersaturation is necessary for cholesterol gallstones to form. Not all people with supersaturated bile form gallstones, however, and additional factors must be present. The role of pronucleating substances has been extensively studied. Of these, proteins, especially mucin, are best understood. Mucin is secreted by the gallbladder epithelium and may act as a nidus for crystal nucleation. Other proteins that may act as pronucleators include alpha 1-acid glycoprotein, alpha 1-antichymotrypsin, phospholipase C, and a small calcium binding protein. The role of antinucleating factors is less well understood. Certain drugs, including octreotide and ceftriaxone, may also predispose to stone formation. Another local factor is gallbladder stasis, a well-known risk factor for pigment stone formation. More recent research has focused on the role of bacterial infection, which has long been believed to be a factor in pigment gallstone formation. Newer data also support a role for infection in cholesterol gallstone pathogenesis. Additionally, genetic factors that may predispose a patient to cholesterol gallstones have been identified in mice and in humans.

Biliary sludge formation during enteral nutrition: prevalence and natural history

BACKGROUND

Total parenteral nutrition is an etiologic factor in the formation of biliary sludge. We studied whether enteral nutrition is also a risk factor for sludge.

METHODS

Fifty patients with a needle catheter jejunostomy (NCJ) placed during a major abdominal operation underwent preoperative and weekly postoperative ultrasonography until NCJ feedings were discontinued (1 to 6 weeks).

RESULTS

All patients were men. The mean age was 63.2 +/- 1.6 years. Fourteen asymptomatic patients (28.0%) had biliary sludge within 2 weeks of beginning enteral feedings through a NCJ. Complete ultrasonographic resolution of sludge was observed in 13 of the 14 positive patients within 1 to 2 weeks of resuming an oral diet. One patient was lost to follow-up after 14 week; a positive sonogram had persisted but the patient remained asymptomatic. During the period of observation, no other patient had signs of biliary tract disease.

CONCLUSIONS

(1) Biliary sludge may form in some patients during enteral feeding with NCJ. (2) Sludge is cleared by the gallbladder once an oral diet is resumed. (3) There appears to be little risk of complications during postoperative enteral feeding.

Prevalence of gallbladder sludge in dogs as assessed by ultrasonography

Ultrasonography of the gallbladder was performed in 3 groups of dogs: 30 clinically healthy dogs, 50 dogs with hepatobiliary disease, and 50 dogs with diseases other than hepatobiliary disease. The gallbladder was evaluated for the presence of sludge (echogenic material without acoustic shadowing). Maximal gallbladder length, width, height, and area were measured as well as the gallbladder wall thickness. The relative sludge area was calculated as the ratio of sludge area over gallbladder area on longitudinal images. No significant difference was found in the prevalence of gallbladder sludge among healthy dogs (53%), dogs with hepatobiliary diseases (62%), and dogs with other diseases (48%). The mean age of dogs with sludge was higher than the mean age of dogs without sludge in dogs with hepatobiliary disease and dogs with other diseases (p < 0.05). The mean relative sludge area did not differ significantly among the 3 groups. A trend to larger gallbladder dimensions in dogs with sludge compared to dogs without sludge was detected within the 3 groups. The gallbladder wall thickness was not different between dogs with and without sludge within the 3 groups. However, the gallbladder wall was more frequently isoechoic than hyperechoic to the liver in dogs with sludge than in dogs without sludge. The results of this study indicate that gallbladder sludge, in dogs, is not particularly associated with hepatobiliary disease and should be considered an incidental finding.

Ground squirrel model for cholelithiasis: role of epithelial glycoproteins

The cholesterol-fed Richardson's ground squirrel (Spermophilus richardsonii) has proven to be an effective animal model in which to study factors that influence cholesterol gallstone formation and associated alterations in the gallbladder epithelium. Ground squirrels of either sex, fed a 2% cholesterol-enriched diet, exhibit cholesterol monohydrate crystal precipitation within 24 hours and macroscopically visible cholesterol stones by 3 weeks. Data on bile chemistry, biliary cholesterol precipitation, and various mucosal alterations occurring prior to, during, and after stone formation were collected using sampling intervals from 6 hours to 20 weeks on the diet. The results indicate that mucin hypersecretion appears to be more closely related to the initiation of nucleation than does either bile calcium of pH. Mucus hypersecretion begins within 18 hours of diet initiation and continues throughout the 20 week experimental period. Apical excrescences became more common and were larger in size during the early stages of cholelithiasis. Administration of aspirin during the experimental period demonstrated an inhibition of mucin synthesis and release. Gallstones were not formed in these aspirin-treated animals. A lectin-binding panel for 10 epithelial glycoprotein-related sugars indicated the mucin secreted by the gallbladder epithelium of 7 day experimental animals differed from that of controls. The most obvious difference was the abolition of WGA binding in the experimental animals, suggesting an absence of sialic acid expression in the mucin during the lithogenic process. Ultrastructural histochemistry indicated that both sulphomucin and sialomucin were present in the secretory granules and within the surface mucus layer of both experimental and control animals. Experimental animals, however, exhibited a significant predominance for sulphomucin. This pattern varies from that typically seen in other regions of the gastrointestinal tract where sialomucins predominate during pathologic processes.

Cirrhosis: a new, but expected cause of biliary sludge

BACKGROUND/AIMS

Biliary sludge is increasingly recognized as a natural stage in gallstone formation. Logically, cirrhosis, a well-documented cause of black pigment cholelithiasis, should be another condition predisposing to the development of sludge. The aim of this study was to assess the prevalence of biliary sludge in an unselected population and to test the hypothesis that cirrhosis could be one of the causes of sludge.

METHODS

We reviewed the clinical findings and ultrasonograms of 2138 patients, hospitalized or not, consecutively seen in our department between January 1993 and December 1994. Sonograms showing biliary sludge mixed with stones were excluded. Three hundred and eighty-eight of the 2138 were cirrhotic patients.

RESULTS

The overall prevalence of biliary sludge was 4%. Sludge was found in 44 of 388 (11%) of the cirrhotic patients (alcoholism, n = 39; chronic viral B hepatitis, n = 3; hemochromatosis, n = 1; and cryptogenic, n = 1), compared with 42 of 1750 (2%) noncirrhotic patients (p < 0.000001). Thirteen cirrhotic patients received intravenous alimentation for 2 to 17 days, 8 were given somatostatin for variceal bleeding, and 7 have previously had 1 to 5 sessions of endoscopic sclerotherapy of esophageal varices with polidocanol.

CONCLUSIONS

This study convincingly demonstrates that cirrhosis must be added to the growing list of conditions associated with biliary sludge.

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.

Cholesterol gallstone formation in man and potential treatments of the gallbladder motility defect

Cholelithiasis affects 10-15% of the adult population in Western society, and about 75% of gallstones are of cholesterol type. Hepatic hypersecretion of cholesterol with the formation of instable cholesterol-rich vesicles in bile, an imbalance between nucleation-inhibiting and nucleation-promoting proteins with further aggregation of cholesterol crystals in a gallbladder with a motility defect (stasis), all play a role in the pathogenesis of cholesterol gallstones. Experimental animal models suggest that gallstone formation can be prevented by improving gallbladder emptying. Thus, a better understanding of the causes underlying the impaired gallbladder motor function in patients with gallstones might lead to the selection of therapeutic approaches for those individuals who are at increased risk for the formation or recurrence of gallstones. The present article focuses on current concepts and theories on the pathogenesis of cholesterol gallstones with emphasis on the gallbladder motility defect. Several treatment strategies for the correction of gallbladder hypomotility are also discussed.

Tumefactive biliary sludge: a sonographic pseudotumour appearance in the common bile duct

Two patients with obstructive biliary symptoms were shown to have dilated bile ducts on ultrasound. Within the lumen of both distal common ducts (CBD) large low echogenicity polypoid masses without acoustic shadowing were seen. MRI in one patient showed a polypoid filling defect in the lower CBD corresponding to the ultrasound appearance. Instrumentation at the lower end of both CBDs caused disintegration of the polypoid configuration resulting in the more typical layered appearance of biliary sludge. Sludge in the gall-bladder as seen on ultrasound is rarely known to cause a pseudotumour appearance. It has not previously been reported as occurring in the CBD and awareness of the tumefactive appearance of biliary sludge in the common duct is important and should help avoid possible misinterpretation.

Choledocho-ureteral anastomosis in the rat. A new experimental model of long-term, total, internal bile diversion

Choledocho-ureteral anastomosis is a new experimental model of total bile diversion in the rat. The anastomosis is carried out using a polyethylene tutor drain and requires neither an external drain nor restraint of the animal. After 14 days of diversion, bile flow fell by 53% and there were no biological signs of cholestasis. The rats survived for up to 2 months. Choledocho-ureteral anastomosis is a reliable and simple experimental model which can be used to study the effects of prolonged interruption of enterohepatic bile-acid circulation.

Cholelithiasis in infancy: a study of 40 cases

During a 17-year period, 40 infants less than 1 year of age were investigated for cholelithiasis; 32 infants were seen within the past 10 years. Seventeen of them had no recognizable predisposing factors. In 6 infants, gallbladder lithiasis was a fortuitous finding on a plain radiograph or sonogram with no signs of common bile duct obstruction; under conservative management, no complications of lithiasis were observed on follow-up of 3 infants and spontaneous resolution occurred in 2 others. In the remaining 34 infants with lithiasis of the common duct or cystic duct or both, the initial symptoms were cholestatic jaundice in 21, acholic stools in 8, sepsis in 4, and abdominal pain in 1. Ultrasonography, performed in 33 of them, showed dilation of the biliary tract in 28, and stones in the gallbladder in 13 and in the bile ducts in 10. Percutaneous transhepatic cholangiography or operative cholangiography in 26 infants showed stones in the bile ducts in 23. In 3 infants, no lithiasis was visible, suggesting the spontaneous elimination of stones. Treatment was initially surgical in 9 infants, but starting in 1981 interventional radiologic procedures were attempted in 15 infants and were successful in 12. Spontaneous resolution of cholelithiasis occurred in 10 other infants with cholestasis. Recurrence of biliary stones was observed in 3 infants only after a follow-up of 7 months to 10 years. These results suggest that common bile duct lithiasis should be considered among the causes of cholestatic jaundice in infancy, and that some of the gallbladder calculi found in older children may have resulted from a lithogenic process that occurred during fetal life or shortly after birth. Percutaneous cholangiography with biliary drainage appears to be an effective means of treatment of infants with common bile duct obstruction; surgery can then be restricted to a limited number of cases, especially those with associated strictures of the bile ducts.

Inositol trisphosphate restores impaired human gallbladder motility associated with cholesterol stones

BACKGROUND

Gallbladder motility is impaired in specimens with cholesterol stones but normal with pigment stones.

METHODS

Muscle cells obtained from 19 human gallbladders with cholesterol stones and 11 with pigment stones were enzymatically digested and contracted with cholecystokinin octapeptide (CCK-8), acetylcholine, and KCl.

RESULTS

Muscle cells from pigment stones had a greater contraction than cells from cholesterol stones. CCK-8-induced contraction was unaffected by calcium-free media but was blocked by strontium. Potassium-evoked contraction was blocked by a calcium-free media and unaffected by strontium. Inositol triphosphate (IP-3)-induced contraction was similar to the contraction caused by CCK-8 in permeable cells from pigment stones but was greater than the response to CCK-8 in cells from cholesterol stones.

CONCLUSIONS

Muscle cells from gallbladders with cholesterol stones contract less than cells from gallbladders with pigment stones; CCK-8-induced contraction only uses stored calcium; and IP-3 causes contractions of equal magnitude in cells from gallbladders with cholesterol and pigment stones. These abnormalities could result from an impaired receptor activation of the mechanism for IP-3 generation and release of stored calcium.

Cholelithiasis in newborns and infants

Cholelithiasis in infants is rare, and has usually been associated with hemolysis, ileal disease, congenital anomalies of the biliary tree, hyperalimentation, and prolonged fasting. With the increased use of abdominal ultrasonography (US), more cases of cholelithiasis are being discovered. We report our experience with 13 infants diagnosed on abdominal US to have gallstones. There were 9 boys and 4 girls with an average age at diagnosis of 2.6 months (range, 0 to 9 months). Predisposing factors could be identified in only 6 of the 13 patients. Two patients with obstructive jaundice underwent cholecystectomy and common bile duct exploration. One patient with choledocolithiasis and common bile duct dilatation was observed. His stone passed spontaneously, with resolution of symptoms. Ten patients without cholestasis remained asymptomatic, with disappearance of lithiasis in five of them. Neonatal cholelithiasis is more common than previously suspected; it seems to affect males more often than females and is usually not associated with known predisposing factors. It appears to be a temporary, self-limiting phenomenon, and an aggressive approach is not warranted in the asymptomatic infant. Surgical or radiological intervention should be reserved for the symptomatic patients or those with underlying lithogenic disorders.

Paradoxical response to cerulein on sphincter of Oddi in the patient with gastrectomy

Sphincter of Oddi motility was measured in 55 gallstone patients either through the sinus tract of percutaneous transhepatic biliary drainage or through the T tube. The influence of cholecystectomy and gastrectomy on the sphincter of Oddi was analyzed by comparing responses in patients with or without surgery to the administration of cerulein and the ingestion of dry egg yolk. When comparing cholecystectomized patients to nonsurgical subjects, cholecystectomy revealed no influence on the response to cerulein and feeding. Both groups showed relaxation of contraction waves after provocations. On the other hand, two thirds of the postgastrectomy patients showed an acceleration in the contractions of the sphincter of Oddi after provocations (one third showed no change), while all of the nongastrectomy group saw the disappearance of the wave after cerulein administration and 83% revealed complete suppression of the wave after feeding. It is suspected that this paradoxical response to CCK on the sphincter of Oddi is a lithogenic factor after gastrectomy.

Therapeutic approaches to the problem of biliary sludge and gallstone formation during total parenteral nutrition

Prolonged total parenteral nutrition is associated with the development of biliary sludge, which consists of super-saturated bile containing cholesterol crystals, bilirubin granules and a very high concentration of mucin glycoprotein. Reduced gallbladder contractility in TPN patients appears to be essential for the pathogenesis of sludge, which represents an important stage in the formation of gallstones, a common and well recognised complication of TPN. Possible approaches to the prevention of these biliary complications of TPN include: 1) inhibition of prostaglandin mediated mucin hypersecretion with aspirin, NSAIDs or possibly by n-3 essential fatty acids; 2) stimulation of gallbladder contractility by early oral feeding or the use of CCK; and 3) reduction of cholesterol saturation and mucin secretion by ursodeoxycholic acid.

Gallbladder sludge and stone formation in relation to contractile function after gastrectomy. A prospective study

In a prospective trial to determine whether gastric surgery induces gallbladder sludge and stone formation, 48 patients with gastric cancer were ultrasonographically examined with simultaneous observation on changes in gallbladder contractile function before and serially for 5 years after gastrectomy. Gallbladder sludge formation was induced with a high frequency of 42% 1 month after gastrectomy, with corresponding significant lowering of gallbladder contractile function. Most of gallbladder sludges, however, disappeared within 12 months in relation to the gradual recovery of gallbladder contractile function. Conversely, gallstone developed in nine patients (18.8%), mostly more than 6 months after gastrectomy. Interestingly, gallstone formation was induced in seven patients who were sludge negative. An evolvement of gallbladder sludge into stone was observed in only two patients, who were, however, treated with intravenous hyperalimentation. This study first provides evidence for the relationship between gastrectomy and a considerably high frequency of incidence of gallbladder sludge and stone in relation to changes in gallbladder kinetics after gastrectomy.

Biliary sludge and microcalculi in intrahepatic bile ducts. Morphologic and X-ray microanalytical observations in 18 among 1,179 consecutively autopsied livers

To clarify the morphology and pathogenesis of intrahepatic calculi in the incipient stage, we examined biliary sludge and microcalculi in intrahepatic bile ducts by morphologic and X-ray microanalytical methods in 18 (1.5%) among 1,179 autopsied livers. The hepatobiliary conditions of these 18 livers were intra- and extrahepatic biliary obstruction in 14 cases, hepatic fibrosis in three cases, and cirrhosis with hepatocellular carcinoma in the remaining one. Grossly, brown-pigmented microcalculi were observed floating in biliary sludge. Microscopically, the biliary sludge was composed of mucin, fibrinous materials, desquamated epithelial cells and a few bilirubin granules. The microcalculi were embedded in the sludge and consisted of mucin and precipitates of bilirubin with a granular, lamellar or amorphous appearance. Bacterial colonies were recognized in both the sludge and microcalculi in all but three cases. Intrahepatic bile ducts harboring sludge and microcalculi showed a minimal to moderate degree of glandular proliferation with mucin production. X-ray microanalysis disclosed that the sludge contained little calcium ion, whereas microcalculi were calcium-rich. These findings suggest that biliary obstruction, bacterial infection and mucin hypersecretion play an important role in the formation of intrahepatic biliary sludge and microcalculi, and that sludge is causally related to the formation of intrahepatic microcalculi. Intrahepatic microcalculi and biliary sludge may represent a pathogenetic sequence in the early stage of calcium bilirubinate hepatolithiasis.

Non-mucin proteins in the matrix of human cholesterol gallstones

Human cholesterol gallstones contain a pigmented organic matrix that may originate from biliary sludge. The cholesterol gallstone matrix contains mucin, bile pigments, and calcium salts. The goal of this study was to examine whether non-mucin proteins are present in the matrix of cholesterol gallstones. Matrix was prepared from cholesterol gallstones from 18 patients. Proteins were identified by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and by molecular sieve high-performance liquid chromatography (HPLC). Two proteins were present in each gallstone and migrated with or just adjacent to standards of bovine serum albumin on SDS-PAGE. Several additional lower molecular weight proteins were identified, but not in every gallstone. Protein fractions contained visible pigment after chloroform extraction, and pigment co-eluted with proteins on HPLC, suggesting binding of pigments to proteins in the matrix. We conclude that low molecular weight proteins are present in the cholesterol gallstone matrix. The major protein appears to be serum albumin, although definitive identification has not been established. The origin of these matrix proteins and their possible significance in the pathogenesis of cholesterol cholelithiasis is unknown.

Short-term fasting increases biliary calcium and bilirubin

Fasting has been associated clinically with the development of gallbladder sludge and pigment gallstones, both of which are composed primarily of calcium bilirubinate. Although fasting has been demonstrated to increase the cholesterol saturation of bile, its effect on biliary calcium and bilirubin has not been investigated. We, therefore, tested the hypothesis that short-term fasting would increase gallbladder bile calcium and bilirubin levels. Fifteen prairie dogs were studied. Seven animals were not fasted, whereas eight were fasted for 16 hr prior to acute experiments. Gallbladder and hepatic bile samples were obtained and analyzed for calcium, bilirubin, pH, and biliary lipids. Gallbladder bile ionized calcium levels were significantly increased in fasted animals (1.7 +/- 0.2 mM) compared to those in nonfasted animals (1.1 +/- 0.1 mM). Similarly, total calcium (4.3 +/- 0.5 mM vs 2.3 +/- 0.3 mM), total bilirubin (63 +/- 12 microM vs 29 +/- 8 microM), and bilirubin monoglucuronide (58 +/- 10 microM vs 22 +/- 8 microM) were significantly increased in the fasted group. Fasted animals were also noted to have an increased biliary cholesterol saturation index (0.57 +/- 0.04 vs 0.36 +/- 0.03) and decreased biliary pH (6.9 +/- 0.1 vs 7.6 +/- 0.1). These data indicate that in the prairie dog short-term fasting results in significant alterations in gallbladder bile composition. The increased concentrations of gallbladder calcium and bilirubin observed in these experiments may account, in part, for the formation of pigment gallstones and gallbladder sludge seen clinically with prolonged fasting.

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.

Spontaneous formation of pigmentary precipitates in bile salt-depleted rat bile and its prevention by micelle-forming bile salts

During studies on the effect of bile salt-pool depletion in the bile-fistula rat (adult male Sprague-Dawley), the spontaneous formation of an orange-brown precipitate was noted. The nature of this phenomenon and its relationship to BS and calcium concentration was investigated in depth. Bile from 18 animals was collected in the dark into transparent tubes containing sodium azide, ascorbic acid, and glucaro-1,4-lactone. The tubes were flushed with nitrogen, sealed, and incubated at 37 degrees C. The pigmentary precipitate formed in all the bile salt-depleted (less than 3-5 mM) bile samples (i.e., those collected after 5-7 h of external biliary drainage), but not in bile salt-rich biles. It appeared within 30-240 min after collection, both in bile samples collected at room temperature and at 37 degrees C, initially as a pale flocculation and then slowly sedimenting to form, after centrifugation, a solid, dark-orange pellet. There were no pH changes during incubation, and bile cultures were negative. Under polarizing microscopy, the precipitate appeared amorphous, and there was no evidence of birefringence. High-performance liquid chromatography showed that unconjugated bilirubin was the prevalent pigmentary component, but significant amounts of monoconjugated bilirubin also coprecipitated. Lipid chemistry showed the presence of lecithin (80.1% of total lipids), which was rich in palmitoyl and linoleoyl fatty acids, and of fatty acids (predominantly palmitic and oleic). Infrared spectroscopy and x-ray diffraction showed the presence of calcium bilirubinate and palmitate. In-vivo replenishment of the bile salt pool by intravenous infusion of either taurocholate or taurochenodeoxycholate (1 mumol/min) completely prevented the pigmentary precipitation. In vitro experiments showed inhibition of the precipitate formation by the addition of individual bile salt in concentrations approximating their critical micellar concentration. Precipitate formation was hastened by the addition of calcium chloride (4-12 mM), but only in bile salt-depleted biles. As the composition of the precipitate closely resembles that of human brown-pigment stones and sludge, these findings may provide new insights into an understanding of the pathogenesis of pigment gallstone disease.

Addition of N-acetylcysteine to aqueous model bile systems accelerates dissolution of cholesterol gallstones

The organic matrix of cholesterol gallstones contains a macromolecular complex of mucin and bilirubin that may inhibit stone dissolution by limiting contact of desaturated bile with crystalline cholesterol. The goal of this study was to determine if the mucolytic agent N-acetylcysteine could accelerate gallstone dissolution in vitro. Paired gallstones were dissolved in either pure taurocholate (140 mM) or ursodeoxycholate (100 mM), or in bovine bile supplemented with either taurocholate or ursodeoxycholate to achieve the same respective bile-salt concentrations. N-acetylcysteine was added to 1 stone from each pair at a concentration of 500 mM in pure bile salts and 100 mM in supplemented bile. Gallstones dissolved significantly faster in bovine bile supplemented with taurocholate or ursodeoxycholate than in pure solutions of the respective bile salts (n = 30, p less than 0.001). N-acetylcysteine significantly accelerated gallstone dissolution in pure solutions of bile acids (n = 30, p less than 0.001 for each) and in supplemented bovine biles (n = 30, p less than 0.001). N-acetylcysteine also significantly increased the frequency of complete gallstone dissolution in taurocholate-supplemented (66.6% vs. 40.0%) and ursodeoxycholate-supplemented (76.6% vs. 50.0%) bile. These results indicate that the mucolytic agent N-acetylcysteine significantly accelerates in vitro gallstone dissolution. We speculate that adjuvant therapy with an appropriate mucolytic agent may potentially increase the efficacy of clinical gallstone dissolution.

Lincomycin treatment of guinea pigs causes formation of pigmented phosphate containing gallbladder sludge and stones

We studied the mechanism of gallbladder sludge formation in guinea pigs (n = 30) treated with lincomycin (80 mg/kg/day) for 7 consecutive days. At sacrifice (day 8) gallbladders of treated animals contained turbid bile, sludge and in one animal a single gallstone. The precipitates were amorphous on X-ray diffraction. Infra-red spectroscopy revealed calcium phosphate as the major component. Compared to saline-treated controls (n = 15) concentrations of total protein, total phosphate and total bilirubin in gallbladder bile were significantly increased (P less than 0.05). The increase in total phosphate was due to the inorganic component, since phospholipid phosphorus was unchanged. The relative amounts of unconjugated bilirubin and of bilirubin mono- and diconjugates in gallbladder bile were unaffected by treatment as was beta-glucuronidase activity. However, sludge was enriched in unconjugated bilirubin compared to gallbladder bile. This was most probably caused by alkaline hydrolysis of bilirubin monoconjugates. To some extent, disproportionation of bilirubin monoconjugates in bile or sludge, either in vivo or during sample preparation, might also have led to increased unconjugated pigment.