Anatomy of a gallstone

The anatomy lesson

To understand gallstones, an anatomy lesson is helpful. The gallbladder is a small, pear-shaped organ that is part of the digestive tract. Located on the right side of the abdomen below your liver, the gallbladder stores and secretes bile (produced in the liver) into your small intestine when food arrives there from your stomach. Bile, a yellow-brownish fluid, helps digest fats in food.

Gallstones form when substances in the bile crystallize, or harden. There are two types of gallstones:

• Cholesterol gallstones - Made mostly of cholesterol, they comprise about 80% of gallstones.
• Pigment gallstones - Made mostly of bilirubin and calcium salts, they account for the remaining 20% of gallstones.

Generally white, yellow or brownish in color, gallstones can be as small as a grain of sand, or as large as a golf ball (though smaller gallstones are much more common). Some people will develop only one or a few larger gallstones, while others can develop hundreds of smaller ones.

What causes gallstones?

Though scientists do not yet understand exactly how gallstones occur, a number of factors are known to contribute to their formation:

• Body chemistry - specifically, when the bile contains too high a concentration of cholesterol and too low a concentration of bile salts.
• Efficiency - how efficient your gallbladder is at contracting and flushing bile.
• Proteins - an improper balance of different types of proteins in the liver or bile may make you more susceptible to gallstones.
• Obesity - being overweight may make you more susceptible to gallstones, probably because it exacerbates the factors listed above.
• Weight loss - the process of losing weight (especially losing weight rapidly) may also make you more susceptible to gallstones, again probably because it exacerbates the factors listed above. (Note: virtually all medical professionals agree that gradual weight loss is highly beneficial to your health, even if it may raise your susceptibility to gallstones.)
• Estrogen levels - In women, increased estrogen levels due to pregnancy, birth control pills or hormone therapy may increase the risk of gallstones.

What does it feel like to have gallstones?

As noted, people who develop gallstones generally don't experience any symptoms for years, and many never develop any symptoms. However, if you do experience a gallstone attack, the symptoms can be severe, and sometimes dangerous. Usually experienced as severe pain in the upper abdomen, upper back or right shoulder, gallstone attacks can last anywhere from 20 minutes to a number of hours, and are often accompanied by nausea and vomiting. Once they occur, attacks may recur very frequently (weeks or months apart) or infrequently (a year or years apart). If you do experience a gallbladder attack, you're likely to have another at some point.

Although very painful, gallstone attacks are usually not life threatening as long as the gallstones remain in the gallbladder. However, if the gallstones migrate out of the gallbladder, serious problems can develop:

• If gallstones migrate and block the duct draining the gallbladder into the small intestine, cholecystitis (inflammation of the gallbladder) can result.
• If gallstones migrate and block the main duct between the liver and the intestine, jaundice and/or pancreatitis (inflammation of the pancreas) can result.

If these complications do develop, and are left untreated, they can be fatal.

How are they diagnosed?

Since asymptomatic gallstones are seldom treated, physicians rarely test for gallstones. However, when symptoms do occur and gallstones are suspected, an ultrasound is generally performed. These devices send sound waves into the abdomen, and if gallstones are present, the waves will bounce back, showing the location of the stones.

Gallstone treatment varies

Once gallstones become symptomatic and are diagnosed, they can be treated in a number of ways.

Surgery

At present, the most common treatment for gallstones is a cholecystectomy surgery to remove the gallbladder. Until recently, this was done through open surgery; a large incision was made into the abdomen to remove the gallbladder. Today, however, the majority of cholecystectomies are performed via laparoscopic surgery. Small incisions are made in the abdomen, and a small camera and surgical tools are then passed through these incisions. Watching on a TV monitor, the surgeon removes the gallbladder, and sutures the internal and external incisions.

Like open surgery, a laparoscopic cholecystectomy is performed under general anesthesia. However, unlike open surgery, the laparoscopic method requires only small incisions, and no cutting of abdominal muscles. As a result, the laparoscopic method causes much less post-operative pain than open surgery, as well as less hospitalization time (overnight compared to several days) and less recuperation time (a few days compared to at least a week).

There are situations when an open cholecystectomy is preferred over the laparoscopic method. Dr. Elizabeth Pomfret, who specializes in hepatobiliary and transplant surgery at Boston's Beth Israel Deaconess Medical Center, explains: "Open cholecystectomies are preferred when the patient has had numerous previous abdominal surgeries, when the patient has a known gangrenous gallbladder, when a patient has cirrhosis, or for patients in whom the anatomy of the bile duct is unclear."

Non-surgical methods

Although much less common, there are non-surgical methods available to treat gallstones. They are only used for cholesterol gallstones.

In oral dissolution therapy you would be asked to ingest medications made from bile acids to dissolve gallstones. Generally lasting anywhere from a few months to a few years, this therapy is usually only prescribed for those patients with very small, cholesterol-type gallstones, since patients with large gallstones often suffer recurrence of symptoms after this therapy.

Contact dissolution therapy involves introducing and removing a gallstone-dissolving agent into the gallbladder through a catheter that is attached to a pump. Lasting hours or days, this type of gallstone treatment is generally limited to those patients for whom any type of surgery poses high risk.

Shock wave therapy, which is relatively new, destroys gallstones by administering a shock wave through the abdomen into the gallbladder. Like oral dissolution treatment, shock wave treatment is limited to patients with few and small gallstones since patients with multiple and/or large gallstones often experience recurrence after treatment.

Who should be tested for gallstones?

In the absence of symptoms, there's generally little purpose for the average person to be tested for gallstones since they are usually not treated unless they become symptomatic. However, if you do experience the type of pain common to gallstones described above, then you should be tested. In addition, if you show evidence of jaundice or any trouble with your pancreas, you should seek medical attention immediately, which should include testing for gallstones.

Are you likely to get gallstones? Anyone can develop them, however, those most susceptible are:

• Women, especially between the ages of 20 and 60, and women who are pregnant, use birth control pills, or receive estrogen hormone therapy (Women are twice as likely to develop gallstones as men.)
• Native Americans and Mexican Americans
• Men and women who are over age 60 or who are overweight
• People who diet, especially those who diet frequently and/or who lose weight quickly (either due to diet or other causes, such as illness or non-gallstone-related surgery)
• People who experienced rapid weight loss or fasting
• People with diabetes
• People who are taking cholesterol-lowering drugs

Life without a gallbladder

Can you live without your gallbladder? Absolutely. As Dr. Pomfret explains, the gallbladder simply functions as a storage area for bile, squirting bile into the small intestines when we eat to help digest the food. Without a gallbladder, bile simply drains directly into the small intestines from the liver at a steady rate all day. Indeed, Dr. Pomfret notes, "We don't really need a gallbladder at all." But two side effects of not having a gallbladder may include increased instances of diarrhea and higher levels of blood cholesterol.

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