Table 18.1 Nomenclature of bone tumors

Cholecystitis

BASIC INFORMATION
DEFINITION
Cholecystitis is an acute or chronic inflammation of the gallbladder generally secondary to gallstones. The initial event in acute cholecystitis is obstruction to gallbladder emptying. In 93% of cases a gallbladder stone can be identified as the cause. Such obstruction results in an increase of gall bladder glandular secretion leading to progressive distension which in turn may compromise the vascular supply to the gall bladder.
There is also an inflammatory response secondary to retained bile within the gallbladder. Infection is a secondary phenomenon following the vascular and inflammatory events described above.
The initial clinical features of an episode of cholecystitis are similar to those of biliary colic described above. However, over a number of hours there is progression with severe localized right upper quadrant abdominal pain corresponding to parietal peritoneal involvement in the inflammatory process. The pain is associated with tenderness and muscle guarding or rigidity. Occasionally the gallbladder can become distended by pus (an empyema) and rarely an acute gangrenous cholecystitis develops which can perforate, with generalized peritonitis.
SYNONYMS
Gallbladder attack

Acute cholecystitis with
A. Covered gall bladder perforation
B. Liver abscess formation in a 70-year-old woman. The arrows indicate multiple gall bladder stones.

EPIDEMIOLOGY & DEMOGRAPHICS
• Acute cholecystitis occurs most commonly in females during the fifth and sixth decades.
• The incidence of gallstones is 0.9% in the general population and much higher in certain ethnic groups (>77% of Native Americans by age 60 years).
PHYSICAL FINDINGS & CLINICAL PRESENTATION
• Pain and tenderness in the right hypochondrium or epigastrium; pain possibly radiating to the infrascapular region
• Palpation of the RUQ eliciting marked tenderness and stoppage of inspired breath (Murphy’s sign)
• Guarding
• Fever (35%)
• Jaundice (25% to 55% of patients)
• Palpable gallbladder (23% of cases)
• Nausea and vomiting (> 72% of patients)
• Fever and chills (> 23% of patients)
• Medical history often revealing ingestion of large, fatty meals before onset of pain in the epigastrium and RUQ

• Intestinal: retrocecal appendicitis, intestinal obstruction, high fecal impaction
• Cardiac: myocardial ischemia (particularly involving the inferior wall), pericarditis
• Cutaneous: herpes zoster
• Trauma
• Fitz-Hugh Curtis syndrome (perihepatitis)
• Subphrenic abscess
• Dissecting aneurysm
• Nerve root irritation caused by osteoarthritis of the spine
WORKUP
Laboratory evaluation and imaging studies
LABORATORY TESTS
• Leukocytosis (12,000 to 20,000) is present in > 73% of patients.
• Elevated alkaline phosphatase, ALT, AST, bilirubin; bilirubin elevation >4 mg/dl is unusual and suggests presence of choledocholithiasis.
• Elevated amylase may be present (consider pancreatitis if serum amylase elevation exceeds 500 U).
IMAGING STUDIES
• Nuclear imaging (HIDA scan) is useful for diagnosis of cholecystitis: sensitivity and specificity exceed 90% for acute cholecystis. This test is only reliable when bilirubin is <5 mg/dl. A positive test will demonstrate obstruction of the cystic or common hepatic duct; the test will not demonstrate the presence of stones.
• Ultrasound of the gallbladder is the preferred initial test; it will demonstrate the presence of stones and also dilated gallbladder with thickened wall and surrounding edema in patients with acute cholecystitis.
• CT scan of abdomen is useful in cases of suspected abscess, neoplasm, or pancreatitis.
• Plain film of the abdomen generally is not useful, because <25% of stones are radiopaque.
TREATMENT
NONPHARMACOLOGIC THERAPY
Provide IV hydration; withhold oral feedings.
ACUTE GENERAL Rx
• Cholecystectomy (laparoscopic is preferred, open cholecystectomy is acceptable); conservative management with IV fluids and antibiotics may be justified in some high-risk patients in order to convert an emergency procedure into an elective one with a lower mortality.
• ERCP with sphincterectomy and stone extraction can be performed in conjunction with laparoscopic cholecystectomy for patients with choledochal lithiasis; approximately 10% to 15% of patients with cholelithiasis also have stones in the common bile duct.
• IV fluids, broad-spectrum antibiotics, pain management (meperidine prn) should be used.
DISPOSITION
• Prognosis is good; elective laparoscopic cholecystectomy can be performed as outpatient procedure.
• Hospital stay (when necessary) varies from overnight with laparoscopic cholecystectomy to 4 to 7 days with open cholecystectomy.
• Complication rate is approximately 1% (hemorrhage and bile leak) for laparoscopic cholecystectomy and <0.5% (infection) with open cholecystectomy.