Cholelithiasis (gallstones) is the deposition of gallstones in the gallbladder which is an organ located under the liver. These gall stones are composed of cholesterol and calcium salts.
Content:
- Quick facts
- Classification of gallstones
- Risk factors or causes of Cholelithiasis
- Complications associated with gallstones
- Clinical manifestations (symptoms)
Quick Facts:
- Cholelithiasis is diagnosed in 10 – 20% of adult populations in high income countries, which makes it one of the common disorders.
- Approximately 20 million people in United States have gallstones.
- For the same reason 7,00,000 cholecystectomies (removal of gall bladder) are performed annually.
Classification of Gallstones:
Generally gallstones are classified on the basis of amount of cholesterol within the stones.
There are two types:
- Cholesterol stones (prevalent in United States and western Europe)
- Pigment stones (predominant in non-western population)
Cholesterol Gallstones: These are composed of more than 50% of crystalline cholesterol monohydrate crystals. Other constituents are calcium bilirubinate and calcium carbonate.
- These stones occur predominantly in the gall bladder.
- They are single, pale yellow and round to ovoid.
- They have finely granular, hard external surface and their cut surface is glistening and shows a radiating crystalline palisade.
- Large in size around 2-4 cm in diameter.
Pigment Gallstones: These are composed of calcium bilirubinate, calcium carbonate and less than 20% of cholesterol. Increased unconjugated bilirubin results in formation of these stones.
Pigment stones are subdivided into black and brown pigment stones.
Black pigment stones: common in India(40%)
- Common in older individuals, cirrhosis (liver damage) conditions.
- Contains 10-90% of calcium bilirubinate, calcium phosphate, calcium carbonate and mucin glycoprotein.
Brown pigment stones: more common in Asia
- Rarely found in the gallbladder. They are formed in the bile duct and cause obstruction in the bile flow leading to infection in the gallbladder and biliary tree.
- Calcium phosphate and calcium carbonate are not usually present in these stones.
Risk factors leading to Gallstones:
Cholesterol stones:
- Age: Prevalence of gall stones increases with age. As age advances increase in gallstones is related to obesity and metabolic syndrome.
- Female Sex hormone: Females are more prone to developing gallstones than males and higher prevalence is observed in premenopausal women. This is due to the effect of estrogen.
- Pregnancy: In the last trimester (a period of three months in pregnancy) of pregnancy, the gall bladder empties more slowly and causes stoppage and increases the coagulation of cholesterol crystals.
- Oral contraceptives increases both uptake and synthesis of cholesterol.
- Drugs like Clofibrate, Octreotide and Ceftriaxone also predisposed to gallstones.
- Obesity enhances cholesterol absorption, synthesis and secretion.
- Diet high in calories and cholesterol.
- Familial predisposition: Gallstones are twice as common in first-degree relatives of patients with Gallstones.
- Metabolic abnormalities like diabetes, hyperlipoproteinemias and PBC (primary biliary cholangitis).
Pigment stones:
- More common in Asians and rural region than in urban.
- Alcoholic cirrhosis.
- Pernicious anemia (caused due to vitamin B12 deficiency).
- Advancing age
- Gastrointestinal diseases
- Chronic hemolytic (destruction of red blood cells)
Complications associated with gallstones:
- Carcinoma: gallstones can increase the risk of cancer of gallbladder.
- Perforation (small hole or row of holes) in the gallbladder.
- Gallbladder empyema: Here the gallbladder gets distended (swells up) with pus.
- Mucocele: Gallbladder gets swollen by cloudy, mucoid material.
- Hydrops of the gallbladder: Distension of gallbladder with watery fluid.
- Cholecystitis: a redness and inflammation of the gallbladder.
- Biliary obstruction: Stones in the bile duct causes obstruction to the flow of bile (a digestive juice).
- Acute pancreatitis: Inflammation of pancreas.
- Biliary fistulas: A fistula is an abnormal connection between two body parts, such as an organ and a blood vessel or another organ. These results from injury or surgery. These are also caused as a result of infection and inflammation. Biliary fistulas may develop between gallbladder and bowel (intestine) or between gallbladder and skin.
- Gallstone ileus: Rarely, a large Stone may erode directly in the adjacent loop of intestine and cause intestinal obstruction.
Clinical features or symptoms of gallstones:
Gallstones may go unnoticed for decades before symptoms develop and 70-80% of patients remain asymptomatic throughout their lives.
Symptomatic patients with biliary colic (presence of stones in the common bile duct of biliary tree) experience intense pain.
Pain is experienced usually after a fatty meal that induces gallbladder contraction, which presses a stone against the gallbladder outlet, leading to increased pressure followed by pain.
The pain is localized in the right upper quadrant of the abdomen or the epigastrium and may radiate to the right shoulder or the back.