Disorders of the Gallbladder
Several disorders affect the biliary system and interfere with nor-mal drainage of bile into the duodenum. These disorders include inflammation of the biliary system and carcinoma that obstructs the biliary tree. Gallbladder disease with gallstones is the most common disorder of the biliary system. Although not all occur-rences of gallbladder inflammation (cholecystitis) are related to gallstones (cholelithiasis), more than 90% of patients with acute cholecystitis have gallstones. Most of the 15 million Americans with gallstones have no pain, however, and are unaware of the presence of stones. For a guide to the terminology associated with biliary disorders and procedures, see Chart 40-1.
Acute inflammation (cholecystitis) of the gallbladder causes pain, tenderness, and rigidity of the upper right abdomen that may ra-diate to the midsternal area or right shoulder and is associated with nausea, vomiting, and the usual signs of an acute inflam-mation. An empyema of the gallbladder develops if the gallblad-der becomes filled with purulent fluid.
Calculous cholecystitis is the cause of more than 90% of cases of acute cholecystitis (Ahmed, Cheung & Keefe, 2000). In cal-culous cholecystitis, a gallbladder stone obstructs bile outflow.
Bile remaining in the gallbladder initiates a chemical reaction; autolysis and edema occur; and the blood vessels in the gallbladder are compressed, compromising its vascular supply. Gangrene of the gallbladder with perforation may result. Bacteria play a minor role in acute cholecystitis; however, secondary infection of bile with Escherichia coli, Klebsiella species, and other enteric organisms occurs in about 60% of patients (Schwartz, 1999).
Acalculous cholecystitis describes acute gallbladder inflamma-tion in the absence of obstruction by gallstones. Acalculous chole-cystitis occurs after major surgical procedures, severe trauma, or burns. Other factors associated with this type of cholecystitis include torsion, cystic duct obstruction, primary bacterial infec-tions of the gallbladder, and multiple blood transfusions. It is speculated that acalculous cholecystitis results from alterations in fluids and electrolytes and in regional blood flow in the visceral circulation. Bile stasis (lack of gallbladder contraction) and in-creased viscosity of the bile are also thought to play a role. The occurrence of acalculous cholecystitis with major surgical proce-dures or trauma makes its diagnosis difficult.