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What Are
Gallstones?
Gallstones form when liquid stored in the gallbladder hardens into pieces
of stone-like material. The liquid, called bile, is used to help the body
digest fats. Bile is made in the liver, then stored in the gallbladder until
the body needs to digest fat. At that time, the gallbladder contracts and
pushes the bile into a tube-called a duct-that carries it to the small intestine,
where it helps with digestion.
Bile contains water, cholesterol, fats, bile salts, and bilirubin. Bile
salts break up fat, and bilirubin gives bile and stool a brownish color.
If the liquid bile contains too much cholesterol, bile salts, or bilirubin,
it can harden into stones.
The two types of gallstones are cholesterol stones and pigment stones. Cholesterol
stones are usually yellow-green and are made primarily of hardened cholesterol.
They account for about 80 percent of gallstones. Pigment stones are small,
dark stones made of bilirubin. Gallstones can be as small as a grain of
sand or as large as a golf ball. The gallbladder can develop just one large
stone, hundreds of tiny stones, or almost any combination.
The gallbladder and the ducts that carry bile and other digestive enzymes
from the liver, gallbladder, and pancreas to the small intestine are called
the biliary system.
Gallstones
can block the normal flow of bile if they lodge in any of the ducts that
carry bile from the liver to the small intestine. That includes the hepatic
ducts, which carry bile out of the liver; the cystic duct, which takes
bile to and from the gallbladder; and the common bile duct, which takes
bile from the cystic and hepatic ducts to the small intestine. Bile trapped
in these ducts can cause inflammation in the gallbladder, the ducts, or,
rarely, the liver. Other ducts open into the common bile duct, including
the pancreatic duct, which carries digestive enzymes out of the pancreas.
If a gallstone blocks the opening to that duct, digestive enzymes can
become trapped in the pancreas and cause an extremely painful inflammation
called pancreatitis.
If any of these ducts remain blocked for a significant period of time,
severe-possibly fatal-damage can occur, affecting the gallbladder, liver,
or pancreas. Warning signs of a serious problem are fever, jaundice, and
persistent pain.
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What causes gallstones?
Cholesterol Stones
Scientists believe cholesterol stones form when bile contains too much
cholesterol, too much bilirubin, or not enough bile salts, or when the
gallbladder does not empty as it should for some other reason.
Pigment Stones
The cause of pigment stones is uncertain. They tend to develop in people
who have cirrhosis, biliary tract infections, and hereditary blood disorders
such as sickle cell anemia.
Other Factors
It is believed that the mere presence of gallstones may cause more gallstones
to develop. However, other factors that contribute to gallstones have
been identified, especially for cholesterol stones.
Obesity. Obesity is a major risk factor for gallstones, especially in
women. A large clinical study showed that being even moderately overweight
increases one's risk for developing gallstones. The most likely reason
is that obesity tends to reduce the amount of bile salts in bile, resulting
in more cholesterol.
Obesity also decreases gallbladder emptying.
Estrogen
Excess estrogen from pregnancy, hormone replacement therapy, or birth
control pills appears to increase cholesterol levels in bile and decrease
gallbladder movement, both of which can lead to gallstones.
Ethnicity
Native Americans have a genetic predisposition to secrete high levels
of cholesterol in bile. In fact, they have the highest rates of gallstones
in the North America. A majority of Native American men have gallstones
by age 60. Among the Pima Indians of Arizona, 70 percent of women have
gallstones by age 30. Mexican-American men and women of all ages also
have high rates of gallstones.
Gender
Women between 20 and 60 years of age are twice as likely to develop gallstones
as men.
Age
People over age 60 are more likely to develop gallstones than younger
people.
Cholesterol-lowering drugs
Drugs that lower cholesterol levels in blood actually increase the amount
of cholesterol secreted in bile. This in turn can increase the risk of
gallstones.
Diabetes
People with diabetes generally have high levels of fatty acids called
triglycerides. These fatty acids increase the risk of gallstones.
Rapid weight loss
As the body metabolizes fat during rapid weight loss, it causes the liver
to secrete extra cholesterol into bile, which can cause gallstones.
Fasting
Fasting decreases gallbladder movement, causing the bile to become overconcentrated
with cholesterol, which can lead to gallstones.
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Who is at risk for gallstones?
- Women
- People over age 60
- Native Americans
- Mexican-Americans
- Overweight men and women
- People who fast or lose a lot of weight quickly
- Pregnant women, women on hormone therapy, and women who use
birth
control pills
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What are the symptoms?
Symptoms of gallstones are often called a gallstone "attack"
because they occur suddenly. A typical attack can cause
-Steady, severe pain in the upper abdomen that increases rapidly and lasts
from 30 minutes to several hours.
- Pain in the back between the shoulder blades
- Pain under the right shoulder
- Nausea or vomiting
Gallstone
attacks often follow fatty meals, and they may occur during the night.
Other gallstone symptoms include
- Abdominal bloating
- Recurring intolerance of fatty foods
- Colic
- Belching
- Gas
- Indigestion
People who also have the following symptoms should see a doctor right
away:
- Sweating
- Chills
- Low-grade fever
- Yellowish color of the skin or whites of the eyes
- Clay-colored stools
Many people with gallstones have no symptoms. These patients are said
to be asymptomatic, and these stones are called "silent stones."
They do not interfere in gallbladder, liver, or pancreas function and
do not need treatment.
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How are
gallstones diagnosed?
Many gallstones, especially silent stones, are discovered by accident
during tests for other problems. But when gallstones are suspected to
be the cause of symptoms, the doctor is likely to do an ultrasound exam.
Ultrasound uses sound waves to create images of organs. Sound waves are
sent toward the gallbladder through a handheld device that a technician
glides over the abdomen. The sound waves bounce off the gallbladder, liver,
and other organs, and their echoes make electrical impulses that create
a picture of the organ on a video monitor. If stones are present, the
sound waves will bounce off them, too, showing their location.
Other tests used in diagnosis include;
Cholecystogram or cholescintigraphy
The patient is injected with a special iodine dye, and x-rays are taken
of the gallbladder over a period of time. (Some people swallow iodine
pills the night before the x-ray.) The test shows the movement of the
gallbladder and any obstruction of the cystic duct.
Endoscopic retrograde cholangiopancreatography (ERCP)
The patient swallows an endoscope-a long, flexible, lighted tube connected
to a computer and TV monitor. The doctor guides the endoscope through
the stomach and into the small intestine. The doctor then injects a special
dye that temporarily stains the ducts in the biliary system. ERCP
is used to locate stones in the ducts.
Blood tests
Blood tests may be used to look for signs of infection, obstruction, pancreatitis,
or jaundice.
Gallstone symptoms are similar to those of heart attack, appendicitis,
ulcers, irritable bowel syndrome, hiatal hernia, pancreatitis, and hepatitis.
So accurate diagnosis is important.
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What
is the treatment?
Surgery
Surgery to remove the gallbladder is the most common way to treat symptomatic
gallstones. (Asymptomatic gallstones usually do not need treatment.) Each
year more than 500,000 Americans have gallbladder surgery. The surgery
is called cholecystectomy.
The standard surgery is called laparoscopic cholecystectomy. For this
operation, the surgeon makes several tiny incisions in the abdomen and
inserts surgical instruments and a miniature video camera into the abdomen.
The camera sends a magnified image from inside the body to a video monitor,
giving the surgeon a closeup view of the organs and tissues. While watching
the monitor, the surgeon uses the instruments to carefully separate the
gallbladder from the liver, ducts, and other structures. Then the cystic
duct is cut and the gallbladder removed through one of the small incisions.
Because the abdominal muscles are not cut during laparoscopic surgery,
patients have less pain and fewer complications than they would have had
after surgery using a large incision across the abdomen. Recovery usually
involves only one night in the hospital, followed by several days of restricted
activity at home.
If the surgeon discovers any obstacles to the laparoscopic procedure,
such as infection or scarring from other operations, the operating team
may have to switch to open surgery. In some cases the obstacles are known
before surgery, and an open surgery is planned. It is called "open"
surgery because the surgeon has to make a 5- to 8-inch incision in the
abdomen to remove the gallbladder. This is a major surgery and may require
about a 2- to 7-day stay in the hospital and several more weeks at home
to recover. Open surgery is required in about 5 percent of gallbladder
operations.
The most common complication in gallbladder surgery is injury to the bile
ducts. An injured common bile duct can leak bile and cause a painful and
potentially dangerous infection. Mild injuries can sometimes be treated
nonsurgically. Major injury, however, is more serious and requires additional
surgery.
If gallstones are in the bile ducts, the surgeon may use ERCP in removing
them before or during the gallbladder surgery. Once the endoscope is in
the small intestine, the surgeon locates the affected bile duct. An instrument
on the endoscope is used to cut the duct, and the stone is captured in
a tiny basket and removed with the endoscope. This two-step procedure
is called ERCP with endoscopic sphincterotomy.
Occasionally, a person who has had a cholecystectomy is diagnosed with
a gallstone in the bile ducts weeks, months, or even years after the surgery.
The two-step ERCP procedure is usually successful in removing the stone.
Nonsurgical Treatment
Nonsurgical approaches are used only in special situations-such as when
a patient's condition prevents using an anesthetic-and only for cholesterol
stones. Stones recur after nonsurgical treatment about half the time.
Oral dissolution therapy
Drugs made from bile acid are used to dissolve the stones. The drugs,
ursodiol (Actigall) and chenodiol (Chenix), work best for small cholesterol
stones. Months or years of treatment may be necessary before all the stones
dissolve. Both drugs cause mild diarrhea, and chenodiol may temporarily
raise levels of blood cholesterol and the liver enzyme transaminase.
Contact dissolution therapy
This experimental procedure involves injecting a drug directly into the
gallbladder to dissolve stones. The drug-methyl tert butyl-can dissolve
some stones in 1 to 3 days, but it must be used very carefully because
it is a flammable anesthetic that can be toxic. The procedure is being
tested in patients with symptomatic, noncalcified cholesterol stones.
Extracorporeal shockwave lithotripsy (ESWL)
This treatment uses shock waves to break up stones into tiny pieces that
can pass through the bile ducts without causing blockages. Attacks of
biliary colic (intense pain) are common after treatment, and ESWL's success
rate is not very high. Remaining stones can sometimes be dissolved with
medication.
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Don't people need their gallbladders?
Fortunately, the gallbladder is an organ that people can live without.
Losing it won't even require a change in diet. Once the gallbladder is
removed, bile flows out of the liver through the hepatic ducts into the
common bile duct and goes directly into the small intestine, instead of
being stored in the gallbladder. However, because the bile isn't stored
in the gallbladder, it flows into the small intestine more frequently,
causing diarrhea in some people. Also, some studies suggest that removing
the gallbladder may cause higher blood cholesterol levels, so occasional
cholesterol tests may be necessary.
Points
to remember
- Gallstones form when substances in the bile harden.
- Gallstones are common among women, Native Americans, Mexican-Americans,
and people who are overweight.
- Gallstone attacks often occur after eating a fatty meal.
- Symptoms can mimic those of other problems, including heart attack,
so accurate diagnosis is important.
- Gallstones can cause serious problems if they become trapped in the
bile ducts.
- Laparoscopic surgery to remove the gallbladder is the most common treatment.
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