Introduction:
Gallbladder sludge is a collection of cholesterol, calcium, bilirubin, and other compounds. These compounds form a buildup in the gallbladder when bile remains in it for a longer period of time; hence it is also called biliary sludge. Bile is a greenish-yellow fluid produced in the liver and stored in the gallbladder, which helps with the digestion of fats. When small particles from the bile stay in the gallbladder for extended periods, they accumulate and form sludge. Gallbladder sludge is a collective buildup of substances in the gallbladder. It cannot be considered a medical condition on its own, but it has the potential to cause gallstones and pancreatitis. It is also known to resolve on its own. Biliary sludge consists of biological elements like mucin, calcium bilirubin, and cholesterol crystals. The association of biliary sludge is commonly observed with prolonged fasting, complete parenteral nutrition, pregnancy, and sickle-cell disease. The history of this condition varies, and it may resolve spontaneously or progress to form gallstones. Persistent occurrence of sludge may give rise to biliary complications.
What Is a Gallbladder Sludge?
The gallbladder is a small pear-shaped organ responsible for storing and releasing bile. It is located in the upper right quadrant of the abdomen, just below the liver. The gallbladder is an integral part of the digestive system, primarily functioning to store bile. Bile is a greenish-yellow body fluid produced and secreted by the liver, and it passes through the bile duct to the gallbladder. The gallbladder stores bile, consisting mainly of 97 % water and components such as bile salts, bilirubin, other bile pigments, fats, and inorganic salts. Bile salts aid in the digestion of fats. The human body produces an average of 400 to 800 milliliters of bile per day in adults. When bile stays in the gallbladder for an extended time, sludge is produced; hence it is also known as gallbladder sludge or biliary sludge. Sludge is defined as a mixture of cholesterol, calcium, bilirubin, and other compounds. Bile plays an important role in digesting fats, but sludge forms if bile particles remain in the gallbladder for too long. Sludge is generally detected through transabdominal ultrasonography, while the microscopy of aspirated bile and endoscopic ultrasonography is more sensitive. Biliary sludge is associated with pregnancy, rapid weight loss (especially in obese individuals), patients with critical illness on low or absent oral intake using total parenteral nutrition (TPN), as well as common bile duct obstruction caused by biliary stones, specific drug usage (e.g., ceftriaxone and octreotide), and bone marrow or solid organ transplantation. The course of biliary sludge varies in different conditions, and it may disappear spontaneously or upon removal of the causative agent. Certain complications caused by the biliary sludge are given below:
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Biliary colic
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Acute cholangitis
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Acute pancreatitis
Some patients with gallbladder sludge or micro-lithiasis remain asymptomatic and do not require therapy. However, in case of complications, cholecystectomy or endoscopic sphincterotomy may be performed. Although there are limited medical therapies available, some show promising effects.
What Is Fetal Gallbladder Sludge?
Fetal sludge is considered an uncommon sonographic finding, and there are few reported incidents in the literature. The actual prevalence is lower than estimated. The etiology of fetal sludge formation is not known and requires further investigation. In many cases, fetal gallbladder sludge resolves spontaneously within a few days or weeks after birth. The presence of gallbladder sludge in the fetus does not hinder fetal prognosis or obstetrical management. When an echogenic mass is observed in the abdominal region of the fetal gallbladder, the diagnosis of gallbladder sludge or stone should be considered, especially in the third trimester of pregnancy.
What Is Infant Gallbladder Sludge?
Gallbladder sludge in infants is uncommon, but increased cases have been observed due to the increased use of ultrasonography (USG). It is often asymptomatic in infants but can sometimes present with conditions such as cholestatic jaundice, transient alcoholic stools, sepsis, and abdominal pain. It is generally a benign condition. Biliary sludge occurring in infants and neonates is usually a benign condition with unclear clinical significance. As mentioned earlier in the article, some cases of gallbladder sludge can be diagnosed prenatally via ultrasonography. In most cases of gallbladder sludge, the condition resolves within 5 to 12 weeks, and almost all patients are asymptomatic. Gallbladder sludge is usually associated with multiple drugs and diseases, such as its presence in neonates and infants treated with ceftriaxone, total parenteral nutrition, and patients with Down syndrome, sickle cell anemia, or congenital hypothyroidism. However, some cases do not show any of the mentioned diseases or disorders. The presence of biliary sludge and gallbladder wall thickening is unclear. In pediatric patients, isolated biliary sludge is not associated with the thickening of the gallbladder wall or acute cholecystitis. Some patients remain asymptomatic, and their gallbladder sludge resolves within a few weeks on its own.
What Are the Management and Observation of Gallbladder Sludge in Infants?
As in many cases, gallbladder sludge resolves spontaneously in up to 50 to 60 percent of neonates or infants. Only a few studies and research have been carried out for such cases, and further investigations are needed. In some cases, physicians may choose to observe pediatric patients until the gallbladder sludge resolves on its own, avoiding surgical intervention. In other cases, suitable medications may be prescribed to promote sludge resolution or prevent it from progressing. Various other types of treatment are performed depending on the severity of the case and other factors such as age.
Conclusion:
Gallbladder sludge is rarely seen in infants and children, with most cases resolving on their own. Ultrasonography aids in the diagnosis of sludge presence. If diagnosed prenatally, it can be managed, and if diagnosed postnatally, it can be treated. Gallbladder sludge is not a life-threatening condition and is not considered a disease, but it has the potential to cause various diseases and disorders. Gallbladder sludge can be effectively managed and treated at any age with a favorable prognosis.
