ERCP and Related Technologies: A Clinical Update

David L. Carr-Locke, MD, FRCP, FACG, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts.

Disclosures

May 22, 2000

In This Article

Cholangitis

This session discussed several topical issues, including severe acute cholangitis and recurrent pyogenic cholangitis.

Dr. Lo[65] began with a description of the original report of cholangitis by Charcot in 1877 and the subsequent addition of hypotension and mental confusion to the original symptom triad by Reynolds and Dargon in 1959, which created the current pentad. He discussed 3 principal factors in the pathogenesis of cholangitis, namely: bacteria in the bile, impedance of bile flow, and local proliferation of bacteria. This combination can overcome the natural defense mechanisms in the biliary tree and allow cholangitis and septicemia to develop. While bile cultures are invariably positive, blood cultures are positive in only a minority of cases. The involved organisms are usually aerobes derived from gut flora, principally Escherichia coli, Klebsiella spp, Enterococcus spp, Proteus spp, and Pseudomonas spp, with anaerobes such as Bacteroides spp and Clostridium spp representing only 4% of the cases. In the Western world, the most common etiologies are choledocholithiasis (approximately 80%), biliary neoplasms, benign biliary strictures, parasites, iatrogenic factors, some congenital factors, and hemobilia, in descending order of frequency.

Once cholangitis is established, certain complications predispose to a high mortality, such as acute renal failure, liver abscess, associated malignant stricture, cirrhosis, and age over 50 years. Disseminated intravascular coagulopathy and respiratory failure may develop in severe cases, and other local complications, such as portal vein thrombosis, may also develop. These phenomena lead to the well-known clinical manifestations of the disease; these manifestations require urgent treatment in more severe forms.

While imaging studies are not required to make the diagnosis, they are important in establishing the cause and in directing therapy. Standard ultrasound and computed tomography (CT), while often used initially, may not be sufficiently sensitive to identify choledocholithiasis or other obstructing pathologies. Magnetic resonance cholangiopancreatography (MRCP) or CT cholangiography may be more accurate, and endoscopic ultrasound (EUS) may be considered, but inevitably, direct cholangiography is the diagnostic gold standard in cholangitis. This can be achieved by ERCP, percutaneous transhepatic cholangiography (PTC), or intraoperatively, depending on available expertise.

In his discussion of medical management, Dr. Lo stated that 80% of patients responded to medical supportive therapy, without the need for urgent intervention. He also discussed various combinations of empiric antibiotic regimens for cholangitis, such as ampicillin + an aminoglycoside, a second-generation cephalosporin + an aminoglycoside, and ciprofloxacin + ampicillin, with or without metronidazole. As Dr. Lo reported, emergency intervention was indicated when the initial presentation was severe or when there was failure to control the condition within 24 hours. ERCP is now firmly established as the treatment of choice for cholangitis after failed medical therapy, and should include bile collection for microbiology, an avoidance of overfilling the biliary tree with contrasts, and adequate bile drainage, irrespective of the etiology. The latter can be achieved by nasobiliary drainage or internal stent placement, and such techniques can occasionally be performed in the ICU setting when fluoroscopy may not be available. Such intervention should be carried out by an appropriately trained endoscopist, and transferring patients to another facility for such treatment must be the decision of the attending physician. Percutaneous drainage is equally successful in draining the biliary tree, particularly when the duct is obstructed. However, there are major complications when compared with ERCP, and a coexistent coagulopathy or ascites may preclude its use.

The traditional approach of surgical intervention with drainage and/or definitive therapy for the causative problem carries a considerable risk, and should only be advocated when nonsurgical methods have failed.

Dr. Chung introduced this topic by attributing the common occurrence of this pathology in East Asia to the formation of calcium bilirubinate stones within the biliary tree. The presence of these stones subsequently leads to obstruction and cholangitis. Although best described by Digby[66] in 1930, there have since been many other descriptions.[67,68,69,70,71] However, the term recurrent pyogenic cholangitis, coined by Cook in 1954,[71] is now commonly used. It is endemic in China, Hong Kong, Japan, Malaysia, and Taiwan, and has been increasingly reported among Asian immigrants to Western countries.[72,73]

The disease is characterized by the presence of sludge and pigment stones in the intrahepatic and extrahepatic ducts, with the left intrahepatic duct being more commonly affected than the right. Stones in the extrahepatic duct are typically large, brown, and soft, whereas intrahepatic stones, frequently associated with strictures, appear darker and harder in consistency. The precise pathogenesis is not known, but its occurrence seems to be associated with lower socioeconomic groups. In addition, bilirubin glucuronide deconjugation is an early phenomenon in the process that allows for the formation of calcium bilirubinate stones. A low-protein diet seems to predispose to this disease as well, by "allowing" a deficiency in natural inhibitors of this process. Once intrabiliary pressure exceeds 20 cm of H2O, cholangio-venous reflux can occur, with resultant septicemia.[74] The clinical features of cholangitis described in the West are equally applicable in the East,[75] and the recent use of MRI has permitted reliable demonstration of these soft ductal calculi.[76]

The aim of treatment is to abort the acute attack and prevent recurrences. Endoscopic drainage is the least invasive method, and definitive endoscopic treatment may be delayed until the patient's condition is more stable.[77,78] Surgical drainage carries a very high risk. The only randomized controlled trial to date has reported a mortality of 32% for surgery and 10% for endoscopic treatment.[79] In recurrent cases, the creation of a hepaticojejunostomy with a cutaneous stoma can allow for further endoscopic interventions without the need for repeated surgery.

Dr. Lehman[80] gave a balanced review of the current standing of MRCP in the diagnostic arena and agreed that, although an efficacious procedure, it does have limitations that must be recognized.

Spatial resolution is still less than that achieved with direct contrast ductography, and sampling of abnormal areas is not possible. Large tumors, stones, and obvious strictures can be confidently diagnosed with MRCP, but more subtle changes, as seen in sclerosing cholangitis, chronic pancreatitis, and small stones less than 3 mm, are often missed. The nature of filling defects may also be difficult to interpret. In centers with advanced endoscopic skills, a diagnostic ERCP is rarely performed without there being the ability to treat any condition encountered. But in smaller centers where this is not the case, a diagnostic MRCP may be more desirable than addressing the risk that would be involved in performing a diagnostic ERCP with limited therapeutic skills. MRI is still a costly undertaking, and Dr. Lehman quoted a price of $1400 for a secretin-stimulated MRCP at his institution. Whether MRCP should become the noninvasive imaging test of choice (vs CT or ultrasound) prior to implementation of invasive studies remains an open question, because no direct comparative studies have been made with particular reference to cost. The appeal of MRCP to diagnose SOD has not yet been realized in terms of accuracy because there seems to be little correlation with abnormal SO manometry.

Dr. Lehman concluded by reaffirming the importance of a team approach to managing pancreatic biliary disease and emphasized that it should also involve using appropriate randomized studies to clarify the position of MRCP as the technology evolves.

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