posted 09-17-1999 09:03 PM
hi spencer,a little more info for you
What is the function of the Gallbladder?
The liver manufactures bile, which is used to help in the digestion of fatty foods. The bile is secreted from the liver cells into small bile ducts, which join together to form the common hepatic duct. The bile then goes into the gallbladder where it is stored and concentrated for later use. When you eat a fatty meal, a hormone called cholecystokinin (CCK) is secreted. It causes the gallbladder to contract and also causes relaxation of a small valve (the sphincter of Oddi) at the end of the common bile duct. This allows bile to flow into the duodenum and mix with food for digestion. After the CCK effect wears off, the valve closes, the gallbladder relaxes, and the cycle is repeated.
What happens if the gallbladder is removed?
If the gallbladder is removed, it would seem that there is no place for the bile to be stored. It turns out that the bile duct system is very compliant or "stretchy," and the bile can be stored within the biliary tree itself. In other words, even though the gallbladder does have a function, the body can "make do" without it, storing the bile within the liver for later use. In any event, if the gallbladder is full of stones or the cystic duct, which connects the gallbladder to the common bile duct, is blocked, the gallbladder is not doing its job anyway.
What Causes Gallstones?
Most gallstones are made of cholesterol, a normal component of bile which is manufactured by the liver as a building block for many important hormones and other compounds. Cholesterol is not soluble in water, so there are other compounds in the bile bile such as bile acids and lecithin which act as detergents to keep the cholesterol in solution. If there is an imbalance such as too much cholesterol or not enough bile acids, the cholesterol can become supersaturated, leading to formation of small crystals and eventually stones.
Estrogen is an important risk factor for gallstone formation; estrogen increases the concentration of cholesterol in the bile. This may explain the increased incidence of gallstones in women as compared to men, as well as in pregnancy, women using birth control pills, and obesity (circulating estrogen levels are increased in women with obesity).
What tests are available to check for gallstones?
The best test currently available is the ultrasound examination. This test uses high-frequency sound waves which are sent out of a special probe into the tissue being examined. The sound waves bounce back to the probe where they are detected, allowing an image to be calculated based on the time taken for the sound waves to go out and come back. This is very similar to sonar depth gauges and fish finders. Gallstones are easy to diagnose because they are so dense that they send a strong echo back to the ultrasound probe. In addition, because they are so dense, sound waves cannot pass through them, causing a a "shadow" to appear on the image behind the gallstones. The ultrasound test also allows examination of the bile duct for evidence of stones or dilation, as well as thickening of the gallbladder or fluid around the gallbladder itself.
Another test is the oral cholecystogram. This test involves taking a medication the day before the examination. The medication is absorbed by the body, excreted into the bile by the liver, and then stored in the gallbladder. The medication is visible on x-rays, so it can be used to outline any stones that may be present in the gallbladder. Plain x-ray films of the abdomen can sometimes show gallstones, but this test is not very sensitive, since only 20% of gallstones are visible on x-ray.
An additional test is the radionuclide scan, commonly called a HIDA scan. This test is usually done to look for evidence of acute cholecystitis. In this case, the cystic duct is blocked by a stone or inflammation. This prevents flow of bile in or out of the gallbladder. The test involves intravenous injection of a very small amount of a radioactive substance or radionuclide. The substance is then excreted by the liver into the bile. In normal circumstances the gallbladder will fill with the radionuclide. A gamma camera is used to visualize the gallbladder and bile ducts. If the gallbladder is visualized, the test is considered to be normal. If the gallbladder is not seen, a diagnosis of acute cholecystitis may be made. A variant of this test is also used in certain patients who have symptoms suggestive of gallbladder disease, but no evidence of gallstones. In this test, called a CCK-HIDA scan, the HIDA scan is done as described above. After the gallbladder is visualized, the hormone cholecystokinin (CCK) is given to cause the gallbladder to contract. By using a computer attached to the gamma camera, the amount of radionuclide ejected from the gallbladder after stimulation with CCK can be calculated and reported. If the "ejection fraction" is very small, one may predict that removal of the gallbladder will relieve the patient's symptoms.
When should the gallbladder be removed?
The presence of gallstones alone does not necessarily mean that the gallbladder should be removed. Some people are found to have gallstones during routine testing for other problems, but have no symptoms related to the gallbladder. These patients can be safely watched until symptoms develop. Many of them will never have a problem and not need to have surgery. On the other hand, once symptoms develop, the gallbladder should be removed. Typical symptoms include upper abdominal or right upper quadrant pain radiating to the back or shoulder. This pain often comes within one to two hours of eating a fatty meal. The pain may be severe, and accompanied by nausea and vomiting. The pain usually subsides within one to four hours. The pain is not relieved by antacids or acid blockers such as Tagamet™ or Pepcid™.
There are also other serious complications of gallstones such as acute cholecystitis, obstructive jaundice, and acute pancreatitis. In acute cholecystitis a stone blocks the outlet of the gallbladder, leading to complete blockage of flow in or out of the gallbladder. This may lead to inflammation of the gallbladder itself. Blockage of the blood flow to the gallbladder may also occur, leading to gangrene and rupture of the gallbladder.
Obstructive jaundice and pancreatitis are related to passage of a stone out of the gallbladder into the common bile duct. If a stone gets stuck at the end of the bile duct it can block the flow of bile, causing the bile to "back up" into the bloodstream. This causes a yellow discoloration of the skin and eyes. Stones can also block the pancreatic duct, which drains into the bowel at the same point as the common bile duct. In this case the pancreas can become inflamed, leading to other life-threatening complications.
Because of all these problems related to gallstones, we recommend surgery for patients who have developed symptoms related to their gallbladder.
Why do you take out the gallbladder instead of just the stones?
More than a hundred years ago, the initial treatment for gallstones was indeed removal of the gallstones and leaving the gallbladder intact. Unfortunately, this procedure does nothing to change the factors which caused the gallstones to form in the first place. It turns out that the gallstones will re-form in more than half the patients within a few years. These facts have been rediscovered in recent years with two nonsurgical treatments for gallstones. One is shock-wave lithotripsy, where the stones are broken down into small fragments with multiple shock waves. The other is Actigall™, the trade-name for ursodeoxycholic acid. This drug is actually a bile acid isolated from bears, which is taken orally and helps to dissolve gallstones. Unfortunately, both of these treatments are very expensive and their effects are only temporary, since the gallstones usually re-form within several years of the treatment.
How is the surgery done?
The traditional operation is called Cholecystectomy (Chole = bile or gall, cyst = bag or bladder, ectomy = removal). This involves an incision in the upper abdomen, from which the gallbladder is dissected out and removed. There are several parts to the operation. First, the cystic duct, which connects the gallbladder to the common bile duct, is identified. At this point the duct may be tied off and divided, or the surgeon may decide to do a test called an operative cholangiogram. This involves making a small opening in the cystic duct and threading a small catheter into the duct. After securing the duct in place, contrast material (dye) is injected into the duct. X-ray pictures are taken which allows the surgeon to check for stones in the main bile duct as well as make sure that the anatomy has been identified properly. After this step, the catheter is removed and the duct is cut and the ends tied off. Next the artery to the gallbladder is identified, clamped, cut, and tied off. Next, the gallbladder is detached from its connection to the liver. The surgeon then checks for evidence of bleeding or bile leakage, and then closes the incision. Recovery from this operation usually involves several days in the hospital, with four to six weeks of further recovery before complete return to normal activities.
Since 1988 a new procedure, called laparoscopic cholecytectomy has become popular. In this operation the exact same procedure is performed; the only difference is that a standard incision is not used. Instead, a narrow telescope with an attached video camera is inserted into the abdomen through a very small incision. The abdomen is inflated with CO2 to create a "room" to work in, and other instruments are inserted through additional small incisions. At the end, the gallbladder is extracted from one of the incisions.
Because no muscles are cut for the procedure, the postoperative pain is dramatically reduced to the point that most patients can return to their usual activities within a week of the surgery.
Mark A. Pleatman, MD, FACS. e-mail email@example.com