Ascending Cholangitis is typically seen in the setting of choledocholithiasis, usually caused by E coli infection and presenting with Charcot’s triad, elevated liver enzymes and dilated bile ducts.
Description
Ascending cholangitis, also known as acute cholangitis, is an infection and inflammation of the bile duct system, characterised by a rapid onset of symptoms. The condition is often caused by a bacterial infection, which results from a blockage in the bile duct that leads to bacterial overgrowth. It is considered a serious, potentially life-threatening condition that requires immediate treatment.
Pathogenesis
The underlying cause of ascending cholangitis is typically the obstruction of the biliary tree, which leads to increased pressure within the ducts and bacterial overgrowth due to stasis of bile. The most common causes of this obstruction include gallstones, strictures, or malignant obstructions. Bacteria then ascend from the duodenum into the bile ducts, leading to inflammation and infection.
The most commonly involved organisms are Gram-negative bacilli, such as Escherichia coli (50%) and Klebsiella (15%), but Gram-positive cocci, including Enterococcus and Streptococcus species, can also be implicated though less commonly.
Epidemiology, Risk Factors & Associations
Ascending cholangitis is relatively rare, with the incidence difficult to quantify due to the various underlying predisposing conditions (i.e., gallstones, malignancies). Key risk factors for ascending cholangitis include:
- Biliary obstruction: Most notably, choledocholithiasis (up to 70% of cases).
- Biliary strictures: Commonly due to iatrogenic injury, chronic pancreatitis, primary sclerosing cholangitis, malignancy (20%).
- Biliary tract manipulations: Including surgical procedures and endoscopic retrograde cholangiopancreatography (ERCP).
- Immunocompromised states: chronic diseases like diabetes mellitus, chronic renal failure, cirrhosis, HIV/AIDS.
Clinical Features
The classical clinical presentation of ascending cholangitis known as Charcot’s triad is seen in 50-70% of cases:
- Fever
- Right upper quadrant pain
- Jaundice.
In more severe cases, patients can exhibit Reynold’s pentad, which adds hypotension and altered mental status to the triad, indicating the onset of septic shock. Other potential symptoms include chills, nausea, and vomiting.
Complications
If left untreated, ascending cholangitis can lead to serious complications, including:
- Sepsis and septic shock: This is the most serious complication and can lead to multi-organ failure and death.
- Liver abscess formation
- Secondary biliary cirrhosis: A result of chronic, repeated episodes of cholangitis.
- Cholangiohepatitis: Inflammation and infection spreading to liver tissue.
- Biliary peritonitis
Subtypes
Ascending cholangitis is typically classified by its severity into mild (grade I), moderate (grade II), and severe (grade III), according to the Tokyo Guidelines.
- Grade I (mild): Systemic inflammation but no organ dysfunction.
- Grade II (moderate): Localised pus formation or organ dysfunction, such as decreased kidney function or altered mental status.
- Grade III (severe): Onset of sepsis or septic shock.
Pathological Features
Histopathology
- Gross: Intrahepatic and extrahepatic bile ducts may appear dilated and filled with pus.
- Histologically, neutrophilic infiltration of the bile ducts, cholangitis, and cholangiohepatitis can be seen. In severe cases, the bile ducts may be distended with pus, and periductal fibrosis may be observed in recurrent or chronic cases.
Radiological Features
Normal bile duct dimensions can vary but generally, the common bile duct (CBD) measures less than 6 mm in patients under the age of 60, and less than 8 mm in patients over the age of 60. The intrahepatic ducts are usually less than 2 mm in diameter.
US
- Dilation and thickening of the intrahepatic and/or extrahepatic bile ducts: A CBD diameter of more than 6-8 mm (depending on age) and intrahepatic ductal dilatation (ducts > 2mm) suggest biliary obstruction.
- Identification of the cause of obstruction: Gallstones appear as hyperechoic structures with posterior acoustic shadowing, while strictures and tumours may be more challenging to visualise.
CT
- Bile duct dilation
- Wall thickening of the bile ducts: Common feature of cholangitis and is not typically seen in simple obstruction.
- Potential causes of obstruction: Gallstones may appear as high-attenuating lesions within the bile ducts. Tumours can manifest as focal mass-like lesions and may cause biliary dilation upstream.
- Complications such as liver abscesses or cholangiohepatitis
MRCP
- Useful for visualising the biliary tree and identifying the location and cause of obstruction.
- Can also identify dilated ducts and any associated complications.
Grading and Staging
The severity of ascending cholangitis is often classified according to the Tokyo Guidelines into three grades (I – mild, II – moderate, III – severe) based on systemic signs of inflammation, organ dysfunction, and the onset of septic shock.
Differential Diagnosis
The differential diagnosis for ascending cholangitis includes other causes of right upper quadrant pain, jaundice, and fever. These might include:
- Acute cholecystitis: This condition may also present with right upper quadrant pain and fever, but the pain is often exacerbated by movement and is associated with a positive Murphy’s sign (pain on deep palpation of the right upper quadrant during inspiration).
- Acute hepatitis: Typically associated with hepatomegaly and elevated liver enzymes, but without evidence of biliary obstruction.
- Pancreatitis: This condition often presents with more diffuse abdominal pain, elevated lipase/amylase levels, and characteristic findings on imaging (e.g., pancreatic enlargement, peripancreatic fluid).
- Liver abscess: Patients with liver abscesses often have right upper quadrant pain and fever but may also have a palpable mass and show a well-circumscribed lesion filled with fluid on imaging.
Management
The management of ascending cholangitis involves the immediate initiation of broad-spectrum antibiotics to cover Gram-negative and anaerobic bacteria, as well as addressing the underlying cause of bile duct obstruction. In many cases, this involves endoscopic retrograde cholangiopancreatography (ERCP) for stone removal or stenting, or potentially surgery for tumours. Urgent consultation with a gastroenterologist for ERCP or a surgeon for possible cholecystectomy is often required.