The formation of gallstones in the gallbladder is the most common disease of the bile ducts.
Gallstones are of three types:
- Stones that contain mainly calcium bilirubin (pigment stones).
- Calculations that have 25 percent or more cholesterol (cholesterol calculations).
- Rocks are composed of variable mixtures of bilirubin and cholesterol (mixed biliary rocks).
Pigments are more common in certain parts of Asia than in the western world. They usually occur in people who have forms of anemia caused by the rapid destruction of red blood cells ( hemolysis ).
Hemolytic disease results from hereditary or acquired abnormal forms of hemoglobin or red blood cell membrane abnormalities in disorders such as sickle cell anemia, thalassemia, or developed hemolytic anemia.
The increased destruction of red blood cells produces abnormally large amounts of bilirubin, the hemoglobin derivative, in the liver, and the consequent secretion in the biliary tract of more significant parts of the water-soluble conjugate, bilirubin diglucuronide, a pigment that is usually secret in the urine.
In the biliary tract, particularly in the gallbladder, part of this bilirubin diglucuronide is broken down by enzymes into insoluble bilirubin in water, forming stones.
Black stones form mainly in the gallbladder and occur in sterile bile. In contrast, brownstones may appear anywhere in the biliary tract in patients with chronic biliary infections and stasis (blood stagnation).
The reasons for the higher incidence of pigmentary stones among people with liver cirrhosis and the elderly are unclear. However, the increased destruction of red blood cells may have a role.
The appearance of pigmentary stones is slightly more common in women. Cholesterol and mixed stones occur when the proportion of cholesterol in the bile exceeds the capacity of the bile acids, and the lecithin phospholipid contains the total amount of cholesterol in the micellar colloidal solution.
When this critical micelle concentration is exceeded and the solution becomes saturated, crystalline cholesterol particles are formed. The resulting gallstones contain large amounts of crystalline cholesterol and smaller amounts of calcium bilirubin.
Gallstones of pure cholesterol are rare. Gallstones of cholesterol occur approximately twice more frequently in women than in men and at younger ages.
Those most at risk for cholesterol gallstones include people who are obese, have diets high in calories or cholesterol, are diabetics, or take female sex hormones.
Each of these factors favors the increase of cholesterol concentrations in the bile. In addition, some people can not, for genetic reasons, convert sufficient amounts of cholesterol into bile acids, which favors the more excellent formation of stones.
Some diseases, such as Crohn’s disease, reduce the ability of the lower small intestine to reabsorb bile acids, which leads to bile acid deficiency that can not be overcome with hepatic synthesis alone.
During pregnancy, the ratio of chenodeoxycholic acid to colic acid in the hepatic bile is reduced, making bile more prone to produce stones.
Decreased bile flow in the gallbladder, a condition that occurs late in pregnancy, in people with low-fat diets and among people with diabetes, also seems to favor the formation of cholesterol stones.
Occasionally, some people produce lithogenic bile, resulting from reduced phospholipids concentrations. The symptoms are likely absent in about half of all gallstone patients.
When they appear, the symptoms are caused by the obstruction of a portion of the bile ducts, most commonly the cystic duct, where it emerges from the gallbladder. This obstruction causes painful contraction of the gallbladder, inflammation of the wall, and acute inflammation ( cholecystitis ).
During a cholecystitis attack, patients often have a fever, acute pain in the upper abdomen (which can also be felt in the right shoulder region), sensitivity in the gallbladder region, and elevations in the white blood cell count.
Symptoms of Cholelithiasis
In some people, gallstones can cause more severe problems if they block bile flow for more extended periods or move to other organs (such as the pancreas or small intestine).
- Temperature greater than 38C (100.4F).
- Fast beats
- Yellowish skin and eyes.
- Chills or tremors.
- Skin itch.
- Little appetite
- More persistent pain
Gallstones are easy to diagnose because the canals, and small channels, in the gallbladder can be easily detected by ultrasonography.
This method can also detect the enlargement of the gallbladder and bile ducts (resulting from the obstruction).
If gallstones are discovered on routine examination or during abdominal surgery for other reasons, and if the patient has no history of gallstone symptoms, nothing needs to be done.
However, the situation is different in symptomatic people who suffer from acute complications, such as cholecystitis or abscesses.
Causes of Cholelithiasis
It is still unclear precisely what leads to this imbalance, but gallstones can form if:
- There are unusually high cholesterol levels inside the gallbladder (approximately four out of every five gallstones are made up of cholesterol).
- There are unusually high levels of a bilirubin product inside the gallbladder (about one in every five gallstones is composed of bilirubin).
The traditional treatment in these cases is the surgical removal of the diseased gallbladder and exploration of the bile ducts by X-rays at the time of stone surgery.
Once the gallbladder and ductal stones are removed, it is unlikely that black pigment or cholesterol stones will be repeated. However, brown pigmented stones may sometimes appear in the bile ducts after cholecystectomy.
Cholesterol gallstones can be dissolved without surgery as long as the gallbladder has retained its ability to concentrate bile and the cystic duct is not obstructed. This is achieved by regular oral administration of drugs made from bile acids called ursodiol and chenodiol.
The ingestion of these drugs increases the number of bile acids in the hepatic bile. It increases the proportion of bile acids concerning cholesterol, which changes the bitterness from lithogenic to non-lithogenic.
This medication should be continued for more than a year. The gallstones of cholesterol dissolve completely and then continue permanently in small doses to avoid the reappearance of stones.