What is Acalculous Cholecystitis?
Acalculous cholecystitis is a type of cholecystitis, or an inflammation of the gallbladder, that happens when there’s a problem with how the gallbladder empties itself. Most people hear about cholecystitis being caused by a blockage in the gallbladder’s outlet, called the cystic duct, usually because of a gallstone. Acalculous cholecystitis, which was first identified in 1844 by someone named Duncan, is a bit different.
While it can come on suddenly, it often develops slowly and is more commonly seen in patients who are very sick and staying in the Intensive Care Unit (ICU). What makes acalculous cholecystitis particularly dangerous is that it’s a life-threatening condition. This is because there’s a higher risk that the gallbladder could develop a hole, known as perforation, or start to die off, a process called necrosis, compared to the usual type of cholecystitis caused by gallstones.
What Causes Acalculous Cholecystitis?
Several factors can cause the gallbladder to not work properly. Going a long time without eating, receiving special types of food through an IV (Total Parenteral Nutrition or TPN), or losing a lot of weight suddenly can all increase the chance of acalculous cholecystitis – a type of gallbladder inflammation that occurs without the presence of gallstones. Often, this happens along with more severe health issues. For example, if you’re in intensive care, recovering from major surgeries or from serious conditions like a stroke, heart attack, severe infections, severe burns, and significant injuries, your risk of developing acalculous cholecystitis is higher.
If the gallbladder isn’t stimulated regularly, it can lead to hardened bile salts and a buildup of pressure within the organ. This can damage the tissue due to lack of blood flow (ischemia), pressure-related tissue death (necrosis), and eventually, a rupture in the gallbladder. This stagnation can also increase the growth of certain harmful bacteria such as Escherichia coli, Klebsiella, Bacteroides, Proteus, Pseudomonas, and Enterococcus faecalis.
It’s also possible for chronic acalculous cholecystitis to occur, which is long-term inflammation of the gallbladder without gallstones. This can lead to decreased function of gallbladder emptying or a condition called hypokinetic biliary dyskinesia. It can be caused by a number of reasons, including changes in hormones, inflammation of blood vessels (vasculitis), and decreased nerve signalling often seen in conditions like diabetes. However, the exact cause of chronic acalculous cholecystitis is often unknown.
Risk Factors and Frequency for Acalculous Cholecystitis
Acalculous cholecystitis is a condition that contributes to 10% of all acute cholecystitis cases, and between 5% and 10% of all cholecystitis cases. It affects males and females equally, but men are more at risk of developing this condition after surgery. If you have a weakened immune system, such as from having HIV, you are more likely to get this condition. This is because individuals with compromised immune systems are at a greater risk of certain infections like microsporidia, cytomegalovirus (CMV), and Cryptosporidium, which can thrive in bile within your gallbladder. Furthermore, people who carry bacteria like Giardia lamblia, Helicobacter pylori, and Salmonella typhi are also at an increased risk of developing cholecystitis.
Signs and Symptoms of Acalculous Cholecystitis
Mild acalculous cholecystitis, which is a type of gallbladder inflammation without gallstones, can manifest similar symptoms to calculous cholecystitis, which is gallbladder inflammation with gallstones. Symptoms typically include pain in the upper right side of the stomach, which intensifies with deep touch (known as Murphy’s sign). Patients may also experience nausea, inability to tolerate certain foods, bloating, and belching.
On the other hand, acute acalculous cholecystitis often appears suddenly with severe upper right abdomen pain. The gallbladder may feel enlarged when touched. These individuals often appear extremely sick and may have signs of body-wide infection (sepsis), typically seen in intensive care units. Although not always, their white blood cell count, an indicator of infection, might be high. These patients are usually already hospitalized due to other severe illnesses or they may be recovering from a major surgery.
Testing for Acalculous Cholecystitis
In simpler terms, a test named cholescintigraphy nuclear scan or HIDA is often used to diagnose chronic acalculous cholecystitis, a condition where the gallbladder is inflamed but no gallstones are found. This test uses a substance called cholecystokinin (CCK) which helps our gallbladder squeeze out the bile. By detecting how much bile the gallbladder can squeeze out (also known as the ejection fraction), any dysfunction can be identified. Specifically, ejection fractions of 35% or less might suggest that the gallbladder isn’t working properly.
Another helpful tool is an ultrasound. If the wall of your gallbladder appears to be thicker than 3.5 mm on the ultrasound, this could be a sign of cholecystitis, which is inflammation of the gallbladder.
Though not directly diagnosing the condition, blood tests also play a significant role. They reveal if you have a higher than normal white blood cell (WBC) count and abnormal liver function, which often suggest that there is an inflammation or infection in your body.
When it comes to acute acalculous cholecystitis where the inflammation of the gallbladder occurs suddenly and without any gallstones, an abdominal ultrasound is usually the first step. This test can reveal a significantly thickened gallbladder wall with swelling and possibly excess fluid around the gallbladder. CT scans also help in making the diagnosis. If the diagnosis is still uncertain, doctors can use a HIDA scan. If acute cholecystitis is present, the gallbladder won’t fill with the special nuclear dye used in HIDA scan.
Treatment Options for Acalculous Cholecystitis
Patients with acalculous cholecystitis, a condition where the gallbladder is inflamed without any gallstones present, are often seriously unwell and need careful treatment. They must be stabilized before anything can be done. If a patient isn’t stable, doctors may think about placing a drainage tube in the gallbladder. This is typically done by a radiologist, a type of doctor who specializes in imaging procedures. Another option could be placing a stent – a small, flexible tube – via a procedure called ERCP (Endoscopic Retrograde Cholangiopancreatography) to help relieve pressure in the gallbladder.
When it comes to treating chronic acalculous cholecystitis, which is a long-term inflammation of the gallbladder without gallstones, it is dealt with the same way as cholecystitis with stones. The best treatment is laparoscopic cholecystectomy, a type of surgery in which the doctor uses small incisions and a camera to remove the gallbladder. An open cholecystectomy, a surgery where a larger cut is made to remove the gallbladder, can also be done if for any reason the laparoscopic method isn’t suitable.
Acute cholecystitis- a sudden inflammation of the gallbladder, needs to be treated quickly. Rapid progression and worsening of the condition can happen if not treated. The best way to treat this is through surgery – either laparoscopic or open- to remove the gallbladder (cholecystectomy). If the patient is too unwell to undergo a major surgery, then doctors might need to drain the gallbladder using a percutaneous method. During this procedure, the doctor uses imaging guidance to insert a thin needle through the skin and into the gallbladder to drain fluid. A more definitive operation to remove the gallbladder might be performed at a later time.
The medical team normally gives antibiotics to manage infections. However, this isn’t always as effective as we would like since the antibiotics don’t always reach the pressurized gallbladder effectively. However, they’re still helpful as they can manage any bloodstream infection.
What else can Acalculous Cholecystitis be?
Some conditions that share similar symptoms include:
- Cholangitis (inflammation of the bile duct)
- Acute cholecystitis (inflammation of the gallbladder)
- Pancreatitis (inflammation of the pancreas)
- Hepatitis (inflammation of the liver)
What to expect with Acalculous Cholecystitis
Acalculous cholecystitis is a serious health condition that carries a high risk of severe illness and death. Reports suggest that the death rate for this disease can range from 30% to 50%, largely depending on the patient’s age. Even for those who survive, recovery from this condition is often a lengthy process that can span several months.
Possible Complications When Diagnosed with Acalculous Cholecystitis
- Rupture of the gallbladder
- Decaying tissue (gangrene) in the gallbladder
- Blood infection (sepsis)
Recovery from Acalculous Cholecystitis
Typically, patients are advised to avoid eating or drinking until their health shows noticeable improvement.
During this time, they need to be given fluids through an intravenous (IV) tube to keep them hydrated.