In a previous outing on the lesions of the gall bladder, we had attempted to differentiate inflammation of the gall bladder known as Cholecystitis from gall stones or Cholelithiasis. We had briefly mentioned Cholangitis, which is the inflammation/infection of the bile ducts.
Having reviewed the situation, we came to the conclusion that Cholangitis deserves a treatise of its own because of its potentially lethal nature.
For a recap, the biliary ductile system includes the right and left hepatic ducts from the right and left lobes of the liver. The two join to form the common hepatic duct. The cystic duct from the gallbladder now joins the hepatic duct to form the common bile duct. This is finally joined by the pancreatic duct as the access the duodenum, which is the beginning of the small intestine. Bile is produced by liver cells and part of it is stored in the gall bladder because of the back pressure exerted by a muscular valvular ring at the entrance of the duct into the lumen of the duodenum known as the sphincter of Odi. Here it becomes concentrated following the absorption of water and salts dissolved in it.
The main function of bile is to eliminate cholesterol and bilirubin from the body as well as emulsification of fats to make them more water soluble during digestion. It must be noted that all bile reach the duodenum through the common bile duct and ampulla of Vater and the flow is controlled by the sphincter of Odi together with pancreatic secretions. An important surgical reminder here is that the basic positioning of the gall bladder and the ductile system can vary from one individual to another. General surgeons know this too well.
Cholangitis is the inflammation of any portion of the bile duct. This inflammation is produced by bacteria infection and sometimes by other conditions like adverse auto immunes response in the body. Bile produced by the liver is sterile. This is due to its antibacterial action as a result of antibodies secreted into the bile and the action of bile acids that inhibit the growth of bacteria and mucus. The small numbers of bacteria that may be present in the ducts and gall bladder usually get there by moving backwards from the duodenum. The backflow could lead to a significant bacteria population but this is usually neutralised by the normal flow of bile out of the ducts into the lumen of the bowel.
However bacteria can reach the ducts from the blood stream and lymphatic vessels. When there is blockade of bile flow as its common in the presence of gall stones, stasis of bile would lead to increased multiplication of with compromised immune system and impairs the capability of the body to fight infection. This it does by impairing the functions of white blood cells and immune hormones or cytokines. This type of inflammation is often referred to as ascending Cholangitis.
Apart from gall stones, other factors that can lead to ascending Cholangitis include narrowing of the lumen of the bile ducts from scarring, gall bladder cancer, cancer of the duodenum, pancreas, ampulla of Vater and certain bacteria that can thrive in oxygen depleted environment known as anaerobes like Clostridium and Bacteriodes. Intestinal worms like Ascaris lumbricoides; liver flukes etc. are also known culprits.
Clinically, a person with Cholangitis may complain of right sided upper abdominal pains. There may be yellowish discolouration of the white portion of the eyes known as the sclera. This is also known as jaundice. The combination of these three symptoms is known as the Charcot’s triad. When added to these three symptoms the presence of septic shock and mental confusion, it becomes Reynolds’s pentad. This portends a grave clinical trend and a medical emergency.
The Diagnosis of Cholangitis will involve blood tests, imaging and endoscopy for obvious reasons. In practice an experienced caregiver can make a reasonably accurate clinical impression based on history and clinical signs as is so commonly practiced in our environment. However routine hematological and liver function tests may be necessary to have a holistic picture and severity of the condition. Blood and bile cultures may be done to ascertain the offending organism(s). The most common bacteria linked to ascending Cholangitis are gram-negative Escherichia coli, Klebsiella and Enterobacter. This is why endotoxic or septic shock is common in acute infection that could be life threatening. Gram-positive Enterococcus also has a relatively high prevalence in Cholangitis.
Medical imaging is used to identify the site and nature of obstruction. For convenience Ultrasound is usually the first to be employed due to its easy availability. It can help to distinguish between Cholangitis and Cholecystitis but is relatively poor at identifying stones farther down the bile ducts. The gold standard test for biliary obstruction is the Endoscopic Retrograde Cholangiopancreatography (ERCP). This basically involves the passing of a tube through the mouth to the duodenum and X-rays taken after a radio opaque contrast medium has been injected. This procedure is also used to commonly unblock the duct. This may involve making a cut in the sphincter of Odi to ease flow of bile or the common bile duct opening dilated with a balloon. Stones can be removed by sucking or pushed into the duodenum.
When available, Magnetic Resonance Imaging (MRI) can be used. The procedure, Magnetic Resonance Cholangiopancreatography (MRCP) has comparable sensitivity to ERCP. The main drawback is that small stones can be missed.
In the presence of other lesions, like cancer, computed tomography (CT) scan and endoscopic ultrasound may be required to give additional information that would aid in the final diagnosis. Lately, endoscopic ultrasound is being employed in the removal of gall stones.
Ascending Cholangitis must be regarded as acute emergency that requires hospitalization.
Intravenous fluids with crystalloids if available must be administered especially in situations of low blood pressure with rapid radial pulse. Broad spectrum antibiotics with combinations of penicillin/Cephalosporins, amino glycosides and Metronidazole should be the caregiver’s first thought. If need be, Vassopressors may be added to this regimen and there should be no hesitation in the use of glucocorticoids. Stabilising the patient should be the ultimate aim.
When this is achieved, other diagnostic and interventionist measures can be commenced. There are so many diagnostic imaging and curative procedures now available that are gradually reducing surgical interventions. The reality now is that the management of Cholangitis is gradually becoming the prerogative of physicians with surgeons being given the distance most advanced climes. This obviously calls for training in the handling of the equipment. But unfortunately in our environment due to resource constraints and limited equipment some surgeons still end up doing cholecystectomy.