Gallstones and Bile Duct Stones
What are gallstones?
Gallstones, which are created in the gallbladder, form when substances in the bile create hard, crystal-like particles. Cholesterol stones, as the name implies, are made of cholesterol and appear light in color. Eighty percent of gallstones are formed this way.
Pigment stones are small, dark stones made of bilirubin and calcium salts that are found in bile. About twenty percent of gallstones are pigment stones. Risk factors for pigment stones include:
- cirrhosis of the liver
- biliary tract infections
- hereditary blood cell disorders (such as sickle cell anemia)
Gallstones can be as small as a grain of salt or as large as a golf ball. The gallbladder may develop many smaller stones, or a single, often large, one. It may even develop several thousand stones.
What are bile duct stones?
Gallstones that move out of the gallbladder can pass into your stomach. However, a stone may become lodged in your bile duct due to the size of the stone or the anatomy of the biliary tree. Bile duct stones are gallbladder stones that have become lodged in the bile duct. Stones that become stuck in the ducts that lead to the duodenum can be both agonizing and dangerous.
What causes gallstones?
Advancements have been made in better understanding the gallstone formation process. Gallstones may be caused by:
- inherited body chemistry
- body weight
- gallbladder movement (the gallbladder is a muscular sack that contracts)
- diet and lifestyle
When the bile contains too much cholesterol and not enough bile salts, cholesterol gallstones may develop. Aside from a high concentration of cholesterol, there are two other factors that seem to be of importance in causing gallstones.
Movement of the gallbladder is refered to as gallbladder motility. This small but muscular organ squeezes to force bile into the bile duct. If the gallbladder does not perform as it should, the bile may not be able to makes its way into the bile duct, instead becoming concentrated and forming small crystals.
Gallstones may also be created by proteins in the liver and bile. These proteins may either promote cholesterol crystallization into gallstones.
Other factors also seem to play a role in causing gallstones but how is not clear.
- Low calorie, and rapid weight-loss diets
- Prolonged fasting
- Increased levels estrogen as a result of pregnancy
- Hormone therapy
- Birth control pills
No clear relationship has been proven between gallstone formation and a particular diet.
Who is at risk for gallstones?
Gallstones affect approximately one million people every year, with women being twice as likely to become afflicted than men. They will join the estimated 20 million Americans —roughly 10 percent of the population— who already have gallstones.
Those who are most likely to develop gallstones are:
- Women, ages 20 – 60
- Men and women, ages 60+
- Men and women who are overweight
- Men and women who go on “crash” diets or who lose of lot of weight quickly
- Pregnant women, or women who have used birth control pills or estrogen replacement therapy
- Native Americans
What are the symptoms of gallstones?
A person with gallstones may have what are called “silent stones”. Studies show that most people with silent stones may not experience any symptoms at all for awhile, remaining symptom-free for years and requiring no treatment. Silent stones may go undiagnosed until they begin to cause discomfort.
For those that are not quite so lucky, the symptoms my include:
- Acute pain, possibly very severe, that occurs very suddenly. It may last a few minutes, or many hours
- Pain is usually located behind your breastbone, but may occur in the upper right abdominal area
- Pain between your shoulder-blades is another symptom of gallstones
- Chills and fever
- Jaundice (a condition in which the skin and eyes develop a yellow pallor)
- Nausea and vomiting
It is not uncommon for attacks to be separated by weeks, months, or even years.
What problems can occur?
A common complication cause by gallstones is blockage of the cystic duct. Sometimes gallstones may make their way out of the gallbladder and into the cystic duct, the channel through which bile travels from the gallbladder to the small intestine. An inflammation of the gallbladder (cholecystitis) can occur if the flow of bile in the cystic duct is severly impeded or blocked by any gallstones.
A less common but more serious problem occurs if the gallstones become lodged in the bile ducts between the liver and the intestine. This condition, called cholangitis, can block bile flow from the gallbladder and liver, causing pain, jaundice and fever.
Gallstones may also interfere with the flow of digestive fluids into the small intestine, leading to an inflammation of the pancreas, or pancreatitis. Prolonged blockage of any of these ducts can cause severe damage to the gallbladder, liver, or pancreas which can be fatal.
How are gallstones diagnosed?
Diagnostic methods for detecting gallstones may include:
- abdominal X-ray,
- computerized axial tomography (CT) scan, or
- abdominal ultrasound that has been taken for an unrelated problem or complaint.
When actually looking for gallstones, the most common diagnostic tool is ultrasound. An ultrasound examination, also known as ultrasonography, uses sound waves to create images of the various abdominal organs .. including the gallbladder. If stones are present, the sound waves will bounce off the stones, revealing their location.
Ultrasound has several advantages.
- It is a noninvasive technique - nothing is injected into or penetrates the body.
- It is painless - there are no known side effects
- It does not involve radiation.
Occassionaly, other tests needed to detect small stones, or verify their non-existance, may be required.
- MRCP uses a magnetic imaging technique. It is painless.
- Endoscopic Ultrasound is a minimally invasive procedure that can visualize tissue near the esophagus and stomach
- ERCP is particularly relevant for diagnosis and management of stones in the bile duct.
Other gallbladder diseases
Pain and inflammation of the gallbladder can occur in the absence of gallstones.
Acalculus cholecystitis, or inflammation of the gallbladder without stones, may occur in conjunction with other severe illnesses. This condition occurs when the gallbladder fluids become infected as a result of being stagnant during a long illness.
Biliary dyskinesia, or disordered function of the gallbladder, describes a condition in which the gallbladder cannot empty properly due to inflammation or spasm of its drainage system (the cystic duct). When you eat a meal, the gallbladder is prompted to contract, and in doing so, bile is forced into the duodenum. If the gallbladder cannot contract, the pressure exerted on the gallbladder causes pain.
A scanning technique, known as an HIDA scan, uses radioactive isotopes to help diagnose both of these conditions. This shows whether the gallbladder is blocked, or cannot drain completely. These conditions are treated in the same way as gallbladder stones.
Cancer, which can develop in the gallbladder wall, appears to be more common in patients with gallstones. Unfortunately, it often does not cause symptoms until the cancer has spread to the liver or adjacent bile duct. If technically possible, surgical removal is the recommended course of action.
Each year more than 500,000 Americans have gallbladder surgery. This surgery, called cholecystectomy, is the most common method for treating gallstones despite the development of some nonsurgical techniques. There are two types of cholecystectomy: the standard “open” cholecystectomy; and, a less invasive procedure called laparoscopic cholecystectomy.
The standard cholecystectomy is a major abdominal surgery in which the surgeon removes the gallbladder through a 5-to-8 inch incision. The person will remain in the hospital for about a week, and convalesce at home for several weeks after.
Laparoscopic cholecystectomy is a more minimally invasive method of gallbladder removal that accounts for approximately 95% of all cholecystectomies performed. Laparoscopic cholecystectomy requires several small incisions in the abdomen to allow the insertion of surgical instruments and a small video camera. The surgeon is provided with a close-up view from inside the body sent by the camera to a video monitor. He is then able to perform the procedure by manipulating his surgical instruments all while watching the monitor.
Laparoscopic cholecystectomy does not require the abdominal muscles to be cut, and thus results in less pain, quicker healing, improved cosmetic results, and fewer complications such as infection. Recovery usually requires only a night in the hospital, and several days recuperation at home.
Several methods are available, but are used only in special circumstances.
Patients with acute inflammation of the gallbladder (and acalculus cholecystitis) may sometimes be treated first with “percutaneous drainage.” This involves inserting a tube and needle (also known as a catheter) straight into the gallbladder to siphon the harmful fluids. Cholecystectomy is performed after the acute situation has settled.
Special medicines can dissolve gallstones which are composed of cholesterol. However, this method works only when there is no blockage, and is usually more practical with smaller stones. However, treatment usually requires many months or years (and stones may return when the treatment is stopped). Thus, it is used only rarely in certain individuals who cannot tolerate surgery.
Extracorporeal shockwave lithotripsy (ESWL) is an excellent method for treating stones in the kidneys. However, ESWL often requires several treatments, and has other drawbacks, including the possibility of stone recurrence. As a result, this treatment method is rarely used.
ESWL can also be used to break up stones in the gallbladder. Resulting stone fragments usually then pass through into the small bowel.
Treatment of bile duct stones
Approximately 10% of patients with stones in the gallbladder also have stones in the bile duct. These can cause acute blockage to the bile duct with “cholangitis” (with infection and jaundice), or acute pancreatitis. When blockage can cause life threatening illness, emergency treatment is best applied with ERCP (endoscopic retrograde cholangiopancreatography). The gastroenterologist passes an endoscope down to the bile duct opening, and then releases the stone into the duodenum with a small cutting incision (sphincterotomy).
There are many options for treating stones in the bile duct which are not causing severe symptoms. Gallstones may be removed during open cholecystectomy. Whilst some experts can remove bile duct stones during the newer less invasive “laparoscopic” cholecystectomy, this technique of laparoscopic common bile duct exploration is available only in a few specialist centers. Laparoscopic cholecystectomy for the gallbladder stones and ERCP for the stones in the bile duct may provide a successful approach for stones in the bile duct. ERCP is used beforehand when it is obvious from the clinical presentation and tests that a stone is present. ERCP can be performed after laparoscopic cholecystectomy when the bile duct stone is found during the operation (by doing an “operative cholangiogram” X-ray).
The above information is adapted from the publication "Gallstones" distributed by the National Digestive Diseases Information Clearinghouse (2 Information Way, Bethesda, MD 20892).