Biliary stones are the commonest cause of cholangitis . Other causes include benign and malignant bile duct strictures, primary sclerosing cholangitis (PSC) , hepato-biliary infection by parasites, recurrent pyogenic cholangitis, acquired immune deficiency syndrome cholangiopathy, and also following ineffective biliary tract instrumentation.

Cholangitis can be characterized by Charcot’s triad , which is defined by fever (seen in about 90 % of patients with cholangitis), abdominal pain (70 %), and jaundice (60 %) [7]. The presence of all three features is considered diagnostic of acute cholangitis [6]. Very sick patients may have additional features of altered mentation (in 10–20 %) and hypotension (in 30 %) resulting in Reynolds’ pentad [8]. Laboratory abnormalities include leukocytosis, hyperbilirubinemia, mild-to-moderate elevations of transaminases and alkaline phosphatase. Severe liver dysfunction with coagulopathy can occur as a result of prolonged or severe cholangitis, often associated with high morbidity and mortality.

Some physicians base their diagnosis on clinical features, whereas others rely more on imaging studies or endoscopic confirmation of biliary obstruction and pus in the biliary tree. Diagnostic criteria for cholangitis called the Tokyo Guidelines were recently updated (Table 6.1) [5, 6]. These criteria combine clinical features, laboratory data, and imaging studies in an attempt to establish the diagnosis and severity of acute cholangitis with greater accuracy [6]. The sensitivity of the Tokyo guidelines is significantly higher than Charcot’s triad (92 versus 26 %) at the expense of decrease in specificity (78 versus 96 %) [6]. Table 6.2 summarizes the criteria for determining severity of cholangitis. Severe cholangitis requires organ dysfunction while moderate cholangitis necessitates a couple of clinical and laboratory findings. Assessing severity is important to determining appropriate timing of biliary drainage . The severity of acute cholangitis can vary from a mild, self-limiting form to life-threatening disease with hemodynamic instability and septic shock. Accurate diagnosis and early severity assessment are imperative to guide the type and timing of therapy.

Several imaging modalities can be considered in patients with acute cholangitis to determine the cause and site of biliary obstruction. These include transabdominal ultrasound (US), abdominal CT scan, magnetic resonance cholangiopancreatography (MRCP), endoscopic ultrasound (EUS) , endoscopic retrograde cholangiopancreatography (ERCP) , and percutaneous transhepatic cholangiography (PTC).

The selection of imaging modality depends on the ease of availability and clinical condition of the patient. Although ERCP is the most sensitive diagnostic test for cholangitis and also offers therapeutic option at the same session, the procedure itself and need for sedation carry significant risks in critically ill patients; therefore, non-invasive imaging studies (US, CT, MRCP) or lower-risk endoscopic tests (EUS) are often required. The choice of imaging modality and the order in which they are performed depends primarily on the clinical stability of the patient and the cause of obstruction.

Ultrasound is usually the initial imaging modality of choice. It is highly sensitive and specific for confirming the presence of gallstones and detecting biliary dilatation; however, its ability to detect bile duct stones is low, with a sensitivity ranging from 20 to 50 % [9]. A CT scan is useful when differential diagnoses include malignancy , chronic pancreatitis, or common bile duct (CBD) stone [10, 11]. MRCP is superior to US and CT for imaging the biliary tree and detecting bile duct stones [10, 11]. The sensitivities of EUS and MRCP for detecting bile duct stones are comparable [12, 13]. However, the accuracy of MRCP for small lesions and stones smaller than 6 mm is limited [14]. EUS is highly sensitive and specific for imaging the biliary tree and the pancreas to evaluate for obstructing lesions, with the additional option of fine-needle aspiration (FNA) in the same session. An EUS evaluation before ERCP is being accepted as a preferred management strategy for patients with low or intermediate probability for bile duct stones or tumor. EUS helps select patients for therapeutic ERCP, which can occur in the same session.

The non-invasive and less invasive tests (US, CT, MRCP, EUS) may be performed in a clinically stable patient with low or moderate likelihood of cholangitis ; however, in a severely ill patient with high probability of cholangitis, it is prudent to proceed directly to ERCP or EUS followed by ERCP. ERCP is the gold standard test for diagnosing biliary obstruction and also serves as a therapeutic modality by facilitating initial biliary drainage. Because it is the most invasive of modalities with highest potential morbidity, ERCP is preferred when a therapeutic intervention is planned and not as a purely diagnostic modality for evaluation of cholangitis [15, 23].

The typical organisms cultured in the blood and bile are the usual bacteria found in the gastrointestinal tract, namely, E. coli, Enterobacter, Enterococcus, and Klebsiella. However, instrumentation may allow Pseudomonas, skin, and oral flora to be introduced into the biliary system [16]. Escherichia and Klebsiella are the most common microorganisms identified in the biliary system with the rate of extended spectrum beta lactamase (ESBL) producers being greater than 20 % [17]. This high rate of ESBL producers in these organisms implies the necessity for broad-spectrum antibiotic coverage when traditional antibiotics are insufficient to control infection [18].

Initial management includes intravenous fluids, broad-spectrum antibiotics, and correction of any underlying coagulopathy. The choice of antibiotic should be based on severity of the illness, setting of infection (community acquired or hospital acquired), presence of underlying hepato-biliary disease, history of biliary instrumentation or surgery such as bilio-enteric anastomosis, age and immune status of the patient, and local susceptibility patterns [4, 6, 19]. For mild-to-moderate cholangitis, 2–3 days of a first or second-generation cephalosporin such as cefoxitin, a penicillin with a β-lactamase inhibitor such as ampicillin and sulbactam, or a fluoroquinolone is recommended. Severe cholangitis can be treated with piperacillin and tazobactam, a third- or fourth-generation cephalosporin such as ceftriaxone with or without metronidazole for 5–7 days. The final antibiotic choice should be tailored to the final blood and bile culture results.

After initial clinical stabilization, biliary decompression should be performed to resolve cholangitis. Non-surgical methods are the procedures of choice, with ERCP preferred over percutaneous drainage. In special circumstances, EUS may be used to assist in drainage either in a rendezvous procedure or in antegrade stent placement.

While patients with mild cholangitis may be treated with antibiotics and elective ERCP, patients with moderate cholangitis should undergo biliary drainage within 24–48 h, and severe cholangitis requires urgent biliary drainage within 24 h. ERCP should not be delayed longer than 72 h as this is associated with worse outcome including death, persistent organ failure, and/or intensive care unit stay and increased length of hospital stay [20].

During ERCP in a patient with cholangitis after wire-guided cannulation, bile and/or pus should be aspirated first to decompress the biliary system and sent for culture. In addition, it may be better to perform a sphincterotomy and allow the infected bile and pus to drain out before injecting contrast to delineate the anatomy. Excessive injection of contrast in the obstructed biliary system should be avoided to prevent systemic spread via cholangio-venous reflux. Contrast should be injected gently and less than the amount of bile aspirated. Even if no definite stones are identified during ERCP, performing biliary sphincterotomy for drainage is reasonable in patients with clinical suspicion of acute cholangitis from choledocholithiasis . In a very sick patient, it is advisable to rapidly establish drainage of the obstructed biliary system by placing a stent or nasobiliary drainage catheter, and later perform an elective ERCP for bile duct clearance. One should remember that patients with obstructed bile ducts are at highest risk of developing septic complications following ERCP, especially when biliary drainage is incomplete [19, 21]. Therefore, if ERCP is unsuccessful especially with retained contrast, urgent biliary drainage percutaneously or with another endoscopist should be performed.

Ascaris lumbricoides or round worm is an actively motile parasite which resides in the proximal small bowel of an infected person. It can invade the papilla and migrate inside the bile duct causing biliary obstruction, cholecystitis, or cholangitis [22]. This migration is enhanced by prior biliary sphincterotomy or bilio-enteric anastomosis [23]. Ascariasis-related biliary disease is common in areas where the rate of Ascaris infection is high. In India, the Kashmir valley is a highly endemic region for ascariasis, exceeding gallstones as a cause of biliary tract disease (37 versus 35 %) [24]. Similarly, in Ecuador, which is also endemic for ascariasis, more than 11 % of patients with gallbladder or biliary tract complications have ascaris worms in their biliary tract [25]. Biliary ascariasis has been reported to account for 10–19 % of ascaris related hospital admissions [24]. Although hepato-biliary ascariasis is common in endemic areas, due to increased and widespread travel and population migration, ascariasis is now a worldwide problem with biliary ascariasis also being reported from non-endemic areas [26, 27].

Diagnosis of biliary ascaris is confirmed by abdominal US or ERCP. Ultrasonographic features suggestive of biliary ascariasis include the presence of long, linear, parallel echogenic structures without acoustic shadowing and the “four lines sign” of non-shadowing echogenic strips with a central anechoic tube representing the digestive tract of the parasite [28].

During endoscopy , the worm can be seen in the duodenum or protruding from the papilla (Fig. 6.5). At ERCP, cholangiographic features of Ascaris worm include the presence of long, smooth, linear filling defects with tapering ends (Fig. 6.6a); smooth, parallel filling defects; curves and loops crossing the hepatic ducts transversely; and dilatation of the CBD [29]. With cholangioscopy, the worm can be visualized directly within the bile duct (Fig. 6.6b).

The “domestic strain” of Echinococcus granulosus or dog tapeworm is the main cause of human hydatid disease . Infections are found worldwide and remain endemic in sheep raising areas. The life cycle involves two hosts: the adult tapeworm is usually found in dogs (definitive host) while the sheep (intermediate host) are the usual host for larval stages. Human exposure is via oral fecal route. Contaminated food or water having embryonated eggs from the feces of dogs, when accidentally ingested by humans, lead to the infection [35]. The embryonated eggs hatch in the small intestine of humans and liberate oncospheres that migrate through the portal circulation to distant sites. The right lobe of the liver is the most common site for hydatid cyst formation. After infection, the vast majority of humans are usually asymptomatic for a long period of time, since cyst growth in the liver is usually slow with growth rate ranging from 1 to 5 mm in diameter per year [36]. In suspected patients, abdominal imaging with ultrasound or CECT combined with serologic studies usually establishes the diagnosis.

In about 25 % of hepatic hydatid patients, the cyst ruptures into the biliary tree causing obstructive jaundice [37, 38]. Contents of the cyst (scolices and daughter cysts) which rupture into biliary tract may cause partial or complete obstruction of bile duct resulting in obstructive jaundice, cholangitis, and sometimes cholangiolytic abscesses. Rarely, acute pancreatitis complicates intra-biliary rupture of hydatid cyst [39].

Cysto-biliary communication is reported in 10–42 % of patients [40, 41]. Cysto-biliary communications are often recognized at surgery when cysts are stained with bile. Unrecognized cysto-biliary communications may present in the post-operative period as a persistent biliary fistula leading to prolonged hospitalization and increased morbidity.