The gallbladder is not a vital organ. It is located on the right side of the abdomen underneath the liver. The gallbladder's function is to store bile, concentrate it, and release it during digestion. Bile is supposed to retain all of its chemicals in solution, but commonly one of them crystallizes and forms sandy or gravel-like particles, and finally gallstones. The formation of gallstones causes gallbladder disease (cholelithiasis).
Chemicals in bile will form crystals as the gallbladder draws water out of the bile. The solubility of these chemicals is based on the concentration of three chemicals: bile acids, phospholipids, and cholesterol. If the chemicals are out of balance, one or the other will not remain in solution. Dietary fat and cholesterol are also implicated in crystal formation.
As the bile crystals aggregate to form stones, they move about, eventually occluding the outlet and preventing the gallbladder from emptying. This blockage results in irritation, inflammation, and sometimes infection (cholecystitis) of the gallbladder. The pattern is usually one of intermittent obstruction due to stones moving in and out of the way. Meanwhile, the gallbladder becomes more and more scarred. Sometimes infection fills the gallbladder with pus, which is a serious complication.
Occasionally, a gallstone will travel down the cystic duct into the common bile duct and get stuck there. This blockage will back bile up into the liver as well as the gallbladder. If the stone sticks at the ampulla of Vater (a narrowing in the duct leading to the pancreas), the pancreas will also be blocked and will develop pancreatitis.
Gallstones will cause a sudden onset of pain in the upper abdomen. Pain will last for 30 minutes to several hours. Pain may move to the right shoulder blade. Nausea with or without vomiting may accompany the pain.
Demographics
Gallstones are approximately two times more common in females than in males. Overweight women in their middle years constitute the vast majority of patients with gallstones in every racial or ethnic group. An estimated 10% of the general population has gallstones. The prevalence for women between ages 20 and 55 varies from 5–20%, and is higher after age 50 (25–30%). The prevalence for males is approximately half that for women in a given age group. Certain people, in particular the Pima tribe of Native Americans in Arizona, have a genetic predisposition to forming gallstones. Scandinavians also have a higher than average incidence of this disease.
There seems to be a strong genetic correlation with gallstone disease, since stones are more than four times as likely to occur among first-degree relatives. Since gallstones rarely dissolve spontaneously, the prevalence increases with age. Obesity is a well-known risk factor since overweight causes chemical abnormalities that lead to increased levels of cholesterol. Gallstones are also associated with rapid weight loss secondary to dieting. Pregnancy is a risk factor since increased estrogen levels result in an increased cholesterol secretion and abnormal changes in bile. However, while an increase in dietary cholesterol is not a risk factor, an increase in triglycerides is positively associated with a higher incidence of gallstones. Diabetes mellitus is also believed to be a risk factor for gallstone development.
Description
Surgery to remove the entire gallbladder with all its stones is usually the best treatment, provided the patient is able to tolerate the procedure. A relatively new technique of removing the gallbladder using a laparoscope has resulted in quicker recovery and much smaller surgical incisions than the 6-in (15-cm) gash under the right ribs that had previously been the standard procedure; however, not everyone is a candidate for this approach. If the procedure is not expected to have complications, laparoscopic cholecystectomy is performed. Laparoscopic surgery requires a space in the surgical area for visualization and instrument manipulation. The laparoscope with attached video camera is inserted. Several other instruments are inserted through the abdomen (into the surgical field) to assist the surgeon to maneuver around the nearby organs during surgery. The surgeon must take precautions not to accidentally harm anatomical structures in the liver. Once the cystic artery has been divided and the gallbladder dissected from the liver, the gallbladder can be removed.
If the gallbladder is extremely diseased (inflamed, infected, or has large gallstones), the abdominal approach (open cholecystectomy) is recommended. This surgery is usually performed with an incision in the upper midline of the abdomen or on the right side of the abdomen below the rib (right subcostal incision).
If a stone is lodged in the bile ducts, additional surgery must be done to remove it. After surgery, the surgeon will ordinarily insert a drain to collect bile until the system is healed. The drain can also be used to inject contrast material and take x rays during or after surgery.
A procedure called endoscopic retrograde cholangiopancreatoscopy (ERCP) allows the removal of some bile duct stones through the mouth, throat, esophagus, stomach, duodenum, and biliary system without the need for surgical incisions. ERCP can also be used to inject contrast agents into the biliary system, providing finely detailed pictures.
Patients with symptomatic cholelithiasis can be treated with certain medications called oral bile acid litholysis or oral dissolution therapy. This technique is especially effective for dissolving small cholesterol-composed gallstones. Current research indicates that the success rate for oral dissolution treatment is 70–80% with floating stones (those predominantly composed of cholesterol). Approximately 10–20% of patients who receive medication-induced litholysis can have a recurrence within the first two or three years after treatment completion.
Extracorporeal shock wave lithotripsy is a treatment in which shock waves are generated in water by lithotripters (devices that produce the waves). There are several types of lithotripters available for gallbladder removal. One specific lithotripter involves the use of piezoelectric crystals, which allow the shock waves to be accurately focused on a small area to disrupt a stone. This procedure does not generally require analgesia (or anesthesia). Damage to the gallbladder and associated structures (such as the cystic duct) must be present for stone removal after the shock waves break up the stone. Typically, repeated shock wave treatments are necessary to completely remove gallstones. The success rate of the fragmentation of the gallstone and urinary clearance is inversely proportional to stone size and number: patients with a small solitary stone have the best outcome, with high rates of stone clearance (95% are cleared within 12–18 months), while patients with multiple stones are at risk for poor clearance rates. Complications of shock wave lithotripsy include inflammation of the pancreas (pancreatitis) and acute cholecystitis.
A method called contact dissolution of gallstone removal involves direct entry (via a percutaneous transhepatic catheter) of a chemical solvent (such as methyl tertiary-butyl ether, MTBE). MTBE is rapidly removed unchanged from the body via the respiratory system (exhaled air). Side effects in persons receiving contact dissolution therapy include foul-smelling breath, dyspnea (difficulty breathing), vomiting, and drowsiness. Treatment with MTBE can be successful in treating cholesterol gallstones regardless of the number and size of stones. Studies indicate that the success rate for dissolution is well over 95% in persons who receive direct chemical infusions that can last five to 12 hours.
Diagnosis/Preparation
Diagnostically, gallstone disease, which can lead to gallbladder removal, is divided into four diseases: biliary colic, acute cholecystitis, choledocholithiasis, and cholangitis. Biliary colic is usually caused by intermittent cystic duct obstruction by a stone (without any inflammation), causing a severe, poorly localized, and intensifying pain on the upper right side of the abdomen. These painful attacks can persist from days to months in patients with biliary colic.
Persons affected with acute cholecystitis caused by an impacted stone in the cystic duct also suffer from gallbladder infection in approximately 50% of cases. These people have moderately severe pain in the upper right portion of the abdomen that lasts longer than six hours. Pain with acute cholecystitis can also extend to the shoulder or back. Since there may be infection inside the gallbladder, the patient may also have fever. On the right side of the abdomen below the last rib, there is usually tenderness with inspiratory (breathing in) arrest (Murphy's sign). In about 33% of cases of acute cholecystitis, the gallbladder may be felt with palpation (clinician feeling abdomen for tenderness). Mild jaundice can be present in about 20% of cases.
Persons with choledocholithiasis, or intermittent obstruction of the common bile duct, often do not have symptoms; but if present, they are indistinguishable from the symptoms of biliary colic.
A more severe form of gallstone disease is cholangitis, which causes stone impaction in the common bile duct. In about 70% of cases, these patients present with Charcot's triad (pain, jaundice, and fever). Patients with cholangitis may have chills, mild pain, lethargy, and delirium, which indicate that infection has spread to the bloodstream (bacteremia). The majority of patients with cholangitis will have fever (95%), tenderness in the upper right side of the abdomen, and jaundice (80%).
In addition to a physical examination, preparation for laboratory (blood) and special tests is essential to gallstone diagnosis. Patients with biliary colic may have elevated bilirubin and should have an ultrasound study to visualize the gallbladder and associated structures. An increase in the white blood cell count (leukocytosis) can be expected for both acute cholecystitis and cholangitis (seen in 80% of cases). Ultrasound testing is recommended for acute cholecystitis patients, whereas ERCP is the test usually indicated to assist in a definitive diagnosis for both choledocholithiasis and cholangitis. Patients with either biliary colic or choledocholithiasis are treated with elective laparoscopic cholecystectomy. Open cholecystectomy is recommended for acute cholecystitis. For cholangitis, emergency ERCP is indicated for stone removal. ERCP therapy can remove stones produced by gallbladder disease.
Aftercare
Without a gallbladder, stones rarely recur. Patients who have continued symptoms after their gallbladder is removed may need an ERCP to detect residual stones or damage to the bile ducts caused by the original stones. Occasionally, the ampulla of Vater is too tight for bile to flow through and causes symptoms until it is opened up.
Risks
The most common medical treatment for gallstones is the surgical removal of the gallbladder (cholecsytectomy). Risks associated with gallbladder removal are low, but include damage to the bile ducts, residual gallstones in the bile ducts, or injury to the surrounding organs. With laparoscopic cholecystectomy, the bile duct damage rate is approximately 0.5%.
Normal results
Most patients undergoing laparoscopic cholecystectomy may go home the same day of surgery, and may immediately return to normal activities and a normal diet, while most patients who undergo open cholecystectomy must remain in the hospital for five to seven days. After one week, they may resume a normal diet, and in four to six weeks they can expect to return to normal activities.
Morbidity and mortality rates
Cholecystectomy is generally a safe procedure, with an overall mortality rate of 0.1–0.3%. The operative mortality rates for open cholecystectomy in males is 0.11% for males aged 30, and 13.84% for males aged 81–90 years. Women seem to tolerate the procedure better than males since mortality rates in females are approximately half those in men for all age groups. The improved technique of laparoscopic cholecystectomy accounts for 90% of all cholecystectomies performed in the United States; the improved technique reduces time missed away from work, patient hospitalization, and postoperative pain.
Alternatives
There are no other acceptable alternatives for gallstone removal besides surgery, shock wave fragmentation, or chemical dissolution.
Bennett, J. Claude, and Fred Plum, eds. Cecil Textbook of Medicine. Philadelphia: W. B. Saunders Co., 1996.
Bilhartz, Lyman E., and Jay D. Horton. "Gallstone Disease and Its Complications." In Sleisenger & Fordtran's Gastrointestinal and Liver Disease, edited by Mark Feldman, et al. Philadelphia: W. B. Saunders Co., 1998.
Fauci, Anthony S., et al., editors. Harrison's Principles of Internal Medicine. New York: McGraw-Hill, 1997.
Feldman, Mark, editor. Sleisenger & Fordtran's Gastrointestinal and Liver Disease, 7th Edition. St. Louis: Elsevier Science, 2002.
Hoffmann, Alan F. "Bile Secretion and the Enterohepatic Circulation of Bile Acids." In Sleisenger & Fordtran's Gastrointestinal and Liver Disease, edited by Mark Feldman, et al. Philadelphia: W. B. Saunders Co., 1998.
Mulvihill, Sean J. "Surgical Management of Gallstone Disease and Postoperative Complications." In Sleisenger & Fordtran's Gastrointestinal and Liver Disease, edited by Mark Feldman, et al. Philadelphia: W. B. Saunders Co., 1997.
Noble, John. Textbook of Primary Care Medicine, 3rd Edition. St. Louis. Mosby, Inc., 2001.
Paumgartner, Gustav. "Non-Surgical Management of Gallstone Disease." In Sleisenger & Fordtran's Gastrointestinal and Liver Disease, edited by Mark Feldman, et al. Philadelphia: W. B. Saunders Co., 1998.
Sabiston Textbook of Surgery, 16th Edition. Philadelphia: W. B. Saunders Co., 2001.
WHO PERFORMS THE PROCEDURE AND WHERE IS IT PERFORMED?
The procedure is performed in a hospital by a physician who specializes in general surgery and has extensive experience in the surgical techniques required.
