Description

Acalculous cholecystitis, also known as acute alithiasic cholecystitis (AAC), is an acute necroinflammatory disease of the gallbladder occurring in the absence of cholelithiasis (1) with a multifactorial pathogenesis (2).

Epidemiology

• AAC accounts 10% of all cases of acute cholecystitis (1,2,3,4). AAC most frequently presents in critically ill patients (status—postsurgical intervention; extensive burn injuries) and the elderly.
• Diabetes mellitus, atherosclerosis, and connective tissue disease are also linked with AAC (2,3).
• Complications occur in about 40% of cases (gangrene, perforation, peritonitis, sepsis, shock).
• Mortality depends on underlying comorbidities reaching as high as 90% in critically ill patients (1).

Etiology and Pathophysiology

The pathogenesis of AAC is multifactorial. Bile stasis and ischemia both likely contribute. Bile stasis can be caused by fasting, obstruction, procedural irritation, and/or ileus. This can lead to bile inspissation that is directly toxic to the gallbladder epithelium. Ischemia may occur as a result of systemic inflammation, iatrogenesis, or shock. Trauma, total parenteral nutrition, viral (hepatotropic virus) or bacterial (mostly gram-negative or anaerobic) infections are also associated with AAC (1,2).

Risk Factors

• Critically ill hospitalized patients
• Recent surgery
• Elderly
• Connective tissue and autoimmune disease
• Extensive burns
• Shock and ischemia
• Trauma
• Parenteral nutrition