Acalculous cholecystitis is responsible for approximately 5–10 percent of all cases of acute cholecystitis, an inflammatory disease of the gallbladder. The majority of acute cholecystitis cases are caused by gallstone obstruction of the cystic duct. However, with acalculous cholecystitis, inflammation still occurs but without the presence of gallstone obstruction.
Acalculous cholecystitis is a severe illness and can be a complication of other medical or surgical conditions. It is associated with a more serious morbidity and higher mortality rates than those caused by gallstones. Acalculous cholecystitis is most commonly seen in very ill patients who are on mechanical ventilation, suffer from sepsis, or even after a severe burn or trauma. The condition affects all races equally at any age, but does have a slight predominance in males over females.
Acalculous cholecystitis types
Acute acalculous cholecystitis (AAC)
Characterized by a sudden development of symptoms in people without gallstones who are critically ill or have been critically injured. Additionally, patients with diabetes, malignant tumors, vasculitis, congestive heart failure, and shock or cardiac arrest may develop acute acalculous cholecystitis. The acute nature is often brought on by ischemia/reperfusion injury, however, bile stasis, opioid therapy, positive pressure ventilation, and total parenteral nutrition have also been found to play a role in development.
Chronic acalculous cholecystitis (CAC)
Having the disease over a long period of time that is also accompanied with biliary pain brought on by chronic gallbladder inflammation. It can be caused by other disorders affecting the biliary tract such as increased basal cystic duct resistance, cystic duct spasm, muscle hypertrophy, and chronic aseptic inflammation in the gallbladder wall.
What causes acalculous cholecystitis?
Occurring in people who are severely ill and debilitated, it is believed that an impairment of blood supply to the gallbladder causes ischemia, leading to inflammation and a diagnosis of acalculous cholecystitis. Another possible cause is that critically ill individuals are unable to eat food normally, which compromises the ability of the gallbladder to contract and release bile. Pregnant women may also develop the condition as well as those with liver dysfunction and chronic infection.
Several risk factors have been linked to the development of acalculous cholecystitis. They include:
- Infection of the bile duct
- Postoperatively, especially after surgery to the abdomen
- Prolonged labor
- Abdominal trauma
- Elderly people
- Extensive burns
- Heart failure
- HIV infection and AIDS
- Severe and prolonged infections with high fevers
Symptoms of acalculous cholecystitis
Acalculous cholecystitis symptoms are similar to those of calculous cholecystitis, which is caused by gallstones. The differentiating feature of acalculous cholecystitis is that sufferers tend to be those who are severely ill or have some other underlying medical condition that presents with its own unique symptoms.
Recognizing the symptoms of acalculous cholecystitis may be difficult for some physicians, as it is relatively rare and typically only presents with fever and a distended abdomen. The following are some of the most pertinent symptoms of acalculous cholecystitis:
- Fever of unknown etiology
- Abdominal distension
- Abdominal tenderness
- Pain in the abdomen and right upper quadrant
- Loss of appetite
- Weakness and lethargy
Diagnosing acalculous cholecystitis
When presented with acute cholecystitis-like symptoms, physicians will immediately assume gallstones are the cause. Also, patient history and a physical exam will also point to the diagnosis of acute cholecystitis, which will prompt testing. A finding of no gallstones supports the diagnosis of acalculous cholecystitis. These tests include:
- Abdominal ultrasound: The use of high-frequency sound waves that can bounce off structures within the abdomen and represented as an image on-screen. This test is non-invasive and can be done in the office. Ultrasound is an excellent test for the presence of gallstones.
- Computed tomography scan (CT): Provides a detailed image of soft tissue structures and will allow doctors to check the gallbladder for gallstones.
- HIDA scan (cholescintigraphy): A radioactive dye is injected into the person, which is then secreted into the bile by the body. At this point, a scan is done on the gallbladder to see if bile is moving as it should throughout the bile system.
How to treat acalculous cholecystitis?
Considering the often critical nature of patients suffering from acalculous cholecystitis, immediate intervention through surgery is indicated as there is a high risk of rapid deterioration and gallbladder perforation. However, those who are not ideal surgery candidates are often put on palliative treatment via endoscopic gallbladder stent placement. This involves placement of a stent between the gallbladder and the duodenum during endoscopic retrograde cholangiopancreatography (ERCP).
Medical management tends to focus on relieving symptoms with the use of pain medications to relieve pain and fever as well as antibiotics to reduce the risk of infection if surgery is to be done.
- Medical care: Immediate administration of intravenous fluids is started in acalculous cholecystitis patients. The use of pain medication and antibiotics will also help to stabilize the patient. Much of the initial management is prep the patient for surgery, as taking out the bladder is the first line form of treatment for the condition.
- Diet: Because the gallbladder plays a role in the digestive system, doctors will often restrict any form of nutrition consumed by mouth and instead rely on IV fluids to keep you hydrated. This is to prevent gallbladder contraction and worsening of symptoms. Once the attack has subsided, a low-fat diet is often implemented as fat is known for making the gallbladder work harder to excrete bile. This may include foods such as lean meats (chicken, turkey, and fish), low or fat-free dairy, and reduced amounts of butter, mayonnaise, and creamy salad dressings.
- Surgical care: The best way to achieve complete resolution of acalculous cholecystitis symptoms. This involves removal of the bladder (cholecystectomy) via laparoscopic surgery as it is minimally invasive and reduces recovery time. Surgery for acalculous cholecystitis has a 96 percent cure rate.
Acalculous cholecystitis vs calculous cholecystitis
|Symptom||Acute Calculous Cholecystitis||Acalculous Cholecystitis|
|Presence of stones||Yes||No|
Acalculous cholecystitis prognosis
Compared to its calculous counterpart, acalculous cholecystitis has a mortality range of 10–50 percent, as opposed to one percent if gallstones were present. Complications are also more likely to occur with acalculous cholecystitis such as perforation and gangrene of the bladder.