Parasites and Biliary stones

Gallbladder stones ٦٣
Gallbladder stones (cholelithiasis)
Gallstones (cholelithiasis) are formed within the gallbladder, an
organ that stores bile excreted from the liver. Bile is made up of bilirubin,
water, salts, lecithin, cholesterol, and other substances. If the
concentration of these components changes, gallstones may form.
Gallstones may be as small as a grain of sand, or they may become as
large as an inch in diameter, depending on how long they have been
forming (Houchen, 2005).
Gallstone disease remains one of the most common medical
problems leading to surgical intervention. During the reproductive years,
the female-to-male ratio is about 4:1, with the sex discrepancy narrowing
in the older population to near equality. The risk factors predisposing to
gallstone formation include obesity, diabetes mellitus, estrogen and
pregnancy, hemolytic diseases, and cirrhosis (Schirmer et al, 2005).
Pathophysiology of gallstone formation:
There are two types of gallstones: cholesterol and pigment stones.
The pathogenesis is divided into three phases: supersaturation, nucleation
and stone growth. Hypersecretion of biliary cholesterol, crystallization
promoting and inhibiting factors, gallbladder hypomotility, arachidonyl
lecithin, prostaglandins, mucin and calcium play an important role in the
formation of gallstones. For the formation of pigment stones a decreased
secretion of biliary acids, an increased secretion of unconjugated bilirubin
into the bile and an infection of the biliary tract are the most important
causative factors (Wermke and Borges, 1993). Crystallization results in
suspension of cholesterol crystals or bilirubinate salts in gallbladder
mucin gel and is known as "biliary sludge". It is believed today that this