cholecystitis

Cholecystitis


The gallbladder, a pear-shaped, hollow, saclike organ, 7.5 to 10 cm (3 to 4 in) long, lies in a shallow depression on the inferior surface of the liver, to which it is attache by loose connective tissue. The capacity of the gallbladder is 30 to 50 mL of bile. Its wall is composed largely of smooth muscle. The gallbladder is connecting to the common bile duct by the cystic duct.
Cholelithiasis is the presence of stones in the gallbladder. Cholecystitis is inflammation of the gallbladder (may be acute or chronic). Choledocholithiasis is the presence of stones in the common bile duct.

Pathophysiology/Etiology
A. Cholelithiasis
1. Stones occur when cholesterol supersaturates the bile in the gallbladder and precipitates out of the bile. The cholesterol-saturated bile predisposes to the formation of gallstones and acts as an irritant, producing inflammatory changes in the gallbladder.
a. Cholesterol stones are the most common type of gallstones found in the United States.
b. Four times more women than men develop cholesterol stones.
c. Women are usually older than 40 years of age, multiparous, and obese.
d. Stone formation increases in users of contraceptives, estrogens, and cholesterol-lowering drugs, which are known to increase biliary cholesterol saturation.
e. Bile acid malabsorption, genetic predisposition, and rapid weight loss are also risk factors for cholesterol gallstones.
2. Pigment stones occur when free bilirubin combines with calcium.
a. Found in patients with cirrhosis, hemolysis, and infections in the biliary tree.
b. These stones cannot be dissolved.
3. An estimated 25 million people in the United States have gallstones, with 1 million new cases discovered each year.
a. Incidence of stone formation increases with age due to increased hepatic secretion of cholesterol and decreased bile acid synthesis.
b. Increased risk in patients with malabsorption of bile salts with GI disease, bile fistula, gallstone ileus, carcinoma of the gallbladder, or in those who have had ileal resection or bypass.
B. Cholecystitis
1. Acute cholecystitis is an acute infection of the gallbladder.
a. If the gallbladder is filled with pus, there is empyema of the gallbladder.
2. Most cases are caused by gallstone obstruction of the cystic duct, causing edema, inflammation, and bacterial invasion. This is called calculous cholecystitis.
3. Acalculous cholecystitis is acute gallbladder inflammation in the absence of obstruction by gallstones.
a. Occurs after major surgical procedures, severe trauma, or burns.
4. Chronic cholecystitis occurs when the gallbladder becomes thickened, rigid, and fibrotic and functions poorly.
a. Results from repeated attacks of cholecystitis, presence of calculi, or chronic irritation.
Clinical Manifestations
1. Gallstones that remain in the gallbladder are usually asymptomatic.
2. Biliary colic can be caused by the presence of gallstones.
a. Steady, severe aching pain or sensation of pressure in the epigastrium or right upper quadrant, which may radiate to the right scapular area or right shoulder.
b. Begins suddenly and persists for 1 to 3 hours until the stone falls back into the gallbladder or is passed through the cystic duct.




3. Acute cholecystitis causes biliary colic pain that persists more than 4 hours and increases with movement, including respirations.
a. Also causes nausea and vomiting, low-grade fever, and jaundice (with stones or inflammation in the common bile duct).
b. Right upper quadrant guarding and Murphy’s sign (inability to take a deep inspiration when examiner’s fingers are press below the hepatic margin) are present.
4. Chronic cholecystitis causes heartburn, flatulence, and indigestion.
a. Repeated attacks of symptoms may occur resembling acute cholecystitis.
5. Rebound tenderness
Diagnostic Evaluation
1. Oral cholecystography, ultrasonography, and hepatobiliary (HIDA) scan may visualize stones or inflammation.
2. ERCP and PTC to visualize location of stones and obstruction.
3. Elevated conjugated bilirubin due to obstruction.
Management
1. Supportive management includes rest, IV fluids, nasogastric suction, pain management, and antibiotics (in the presence of a positive culture).
2. Surgical management.
a. Cholecystectomy, open or laparoscopic.
b. Intraoperative cholangiography and choledochoscopy for common bile duct exploration.
c. Placement of a T-tube in the common bile duct to decompress the biliary tree and allow access into the biliary tree postoperatively.
3. Oral therapy with chenodeoxycholic acid (CDCA), ursodeoxycholic acid (Actigall), or a combination of both to decrease the size of existing cholesterol stones or dissolve small ones.
a. Indicated for patients at high risk for surgery because of age or systemic disease.
b. Major adverse effects include diarrhea, abnormal liver function tests, and increases in serum cholesterol.
4. Direct contact therapy where a local cholelitholytic agent is infused directly into the gallbladder through a percutaneous transhepatic catheter.
a. Indicated for symptomatic, high-risk patients whose gallbladder can be visualized on oral cholecystography.
b. Side effects include pain from the catheter, nausea, transient elevations of liver function tests and white blood count.
5. Intracorporeal lithotripsy is used to fragment stones in the gallbladder or common bile duct by ultrasound, pulsed laser, or hydraulic lithotripsy applied through an endoscope directly to the stones. The stone fragments are removed by irrigation and aspiration. A cholecystectomy may then be performed.