Acalculous cholecystitis is an acute necroinflammatory disease of the gallbladder with a multifactorial pathogenesis. It accounts for approximately 10 percent of all cases of acute cholecystitis and is associated with high morbidity and mortality rates.
This topic will review the pathophysiology, diagnosis, and treatment of acalculous cholecystitis. Clinical issues related to acute calculous cholecystitis are discussed separately. (See "Acute cholecystitis: Pathogenesis, clinical features, and diagnosis" and "Treatment of acute cholecystitis".)
The conditions associated with acalculous cholecystitis (table 1) lead to gallbladder stasis and ischemia, which then result in a local inflammatory response in the gallbladder wall. In the majority of patients, multiple risk factors are present [1-7]. Pathologically, there is endothelial injury, gallbladder ischemia, and stasis, leading to concentration of bile salts, gallbladder distension, and eventually necrosis of the gallbladder tissue. Once acalculous cholecystitis is established, secondary infection with enteric pathogens, including Escherichia coli, Enterococcus faecalis, Klebsiella, Pseudomonas, Proteus species, and Bacteroides is common . Perforation occurs in severe cases [9,10].
While secondary infection of the gallbladder is common, in some cases, specific primary infections predispose to acalculous cholecystitis and should be managed appropriately (table 2). As an example, acalculous cholecystitis occurring in patients with acquired immunodeficiency syndrome (AIDS) and other immunosuppressed patients may be due to opportunistic infections such as microsporidia, Cryptosporidium, or cytomegalovirus . More often, however, these infections cause a cholangiopathy without cholecystitis. (See "AIDS cholangiopathy".)
Acalculous cholecystitis is typically seen in patients who are hospitalized and critically ill, though it may also be seen in the outpatient setting. Acalculous cholecystitis has been reported in 0.7 to 0.9 percent of patients following open abdominal aortic reconstruction, in 0.5 percent of patients following cardiac surgery, and in as many as 4 percent of patients who have undergone bone marrow transplantation [4,12-15]. There is a strong male predominance among patients with acute cholecystitis following surgery in the absence of trauma (80 percent) .