Acalculous cholecystitis is a severe illness that is a complication of various other medical or surgical conditions. Duncan first recognized it in 1844 when a fatal case of acalculous cholecystitis complicating an incarcerated hernia was reported. The condition causes approximately 5-10% of all cases of acute cholecystitis and is usually associated with more serious morbidity and higher mortality rates than calculous cholecystitis. It is most commonly observed in the setting of very ill patients (eg, on mechanical ventilation, with sepsis or severe burn injuries, after severe trauma ). In addition, acalculous cholecystitis is associated with a higher incidence of gangrene and perforation compared to calculous disease.
The usual finding on imaging studies is a distended acalculous gallbladder with thickened walls (>3-4 mm) with or without pericholecystic fluid. Acalculous cholecystitis can be observed in patients with human immunodeficiency virus (HIV) infection, although it is a late manifestation of this disease. Acalculous cholecystitis can also be found in patients on total parenteral nutrition (TPN), typically those on TPN for more than 3 months.
The main cause of this illness is thought to be bile stasis and increased lithogenicity of bile. Critically ill patients are more predisposed because of increased bile viscosity due to fever and dehydration and because of prolonged absence of oral feeding resulting in a decrease or absence of cholecystokinin-induced gallbladder contraction. Gallbladder wall ischemia that occurs because of a low-flow state due to fever, dehydration, or heart failure may also play a role in the pathogenesis of acalculous cholecystitis.
Acalculous cholecystitis comprises approximately 5-10% of all cases of acute cholecystitis.
The mortality and morbidity rates associated with acalculous cholecystitis can be high; the illness is frequently observed in patients with sepsis or other serious conditions. The reported mortality range is 10-50% for acalculous cholecystitis as compared to 1% for calculous cholecystitis.
A study by Gu et al found a significantly higher frequency of cerebrovascular accidents in patients with acute acalculous cholecystitis (AAC) than those with acute calculous cholecystitis (ACC), the respective rates being 15.9% and 6.7%. The incidence of gangrenous cholecystitis was also greater in the AAC than in ACC (31.2% vs 5.6%, respectively).
It can occur in all races.
Acalculous cholecystitis has a slight male predominance, unlike calculous cholecystitis, which has a female predominance.
The condition can occur in persons of any age, although a higher frequency is reported in persons in their fourth and eighth decades of life.
History findings are of limited value. Often, many patients are very ill (possibly on mechanical ventilation) and cannot communicate a history or symptoms.
Physical examination may reveal fever and right upper quadrant tenderness.
The main cause of acalculous cholecystitis is gallbladder stasis with resulting stagnant bile. This is observed most commonly in patients with sepsis, patients in intensive care units, patients on long-term TPN, patients with diabetes (occasionally), or other patients with gallbladder dysmotility. The condition has also been reported during pregnancy, as a complication of hepatitis A. It has been rarely reported in children, also as a complication of hepatitis A, with a favorable course with conservative treatment.
When the diagnosis of acalculous cholecystitis is established, immediate intervention is indicated because of the high risk of rapid deterioration and gallbladder perforation.
In patients with acalculous cholecystitis who are high-risk surgical candidates (ie, end-stage liver disease), endoscopic gallbladder stent placement has been reported as an effective palliative treatment. This involves placement of a double pigtail stent between the gallbladder and the duodenum during endoscopic retrograde cholangiopancreatography (ERCP). However, the definitive treatment of acalculous cholecystitis is cholecystectomy for patients who are able to tolerate surgery.
The aforementioned study by Gu et al, however, indicated that in selected patients with acute acalculous cholecystitis (AAC), nonsurgical treatment (such as antibiotics or percutaneous cholecystostomy) may be an effective alternative to surgery. In the study, data from 69 patients with AAC was compared with those from 415 patients with acute calculous cholecystitis (ACC). The investigators found that among those patients who underwent nonsurgical therapy, the posttreatment recurrence rate was just 2.7% in the AAC group, compared with 23.2% in the ACC patients.
In surgical candidates, open or laparoscopic cholecystectomy is indicated. In patients who are not surgical candidates, percutaneous cholecystostomy may be performed in the radiology suite. Catheters are usually removed after approximately 3 weeks in critically ill patients with acalculous cholecystitis who have undergone percutaneous cholecystostomy. This allows for the development of a mature track from the skin to the gallbladder.
Patients in the acute stage of acalculous cholecystitis should receive nothing by mouth. Hydration with intravenous fluids should be provided.
Administer broad-spectrum antibiotics for enteric and biliary pathogen coverage. Definitive treatment is cholecystectomy in patients who are surgical candidates or cholecystostomy in patients who are not surgical candidates.