Pancreaticobiliary disorders A look at frequently encountered problems of the digestive system BY Arni Sekar, MD

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In order for digestion to occur, bile and pancreatic enzymes are secreted through the papilla of Vater (major duodenal papilla) and into the second or descending part of the duodenum. Both the biliary tree and the pancreatic duct share a common channel at Vater's ampulla (the hepatopancreatic ampulla). Consequently, it's not surprising that diseases of either system can affect the other, particularly when the main pancreatic duct and the common bile duct are involved. The following will discuss clinical scenarios involving the pancreaticobiliary system, such as common bile duct stones, strictures, and acute and chronic pancreatitis that physicians are likely to encounter in practice.

The cornerstone of managing these disorders is endoscopic retrograde cholangiopancreatography (ERCP), a procedure where at duodenoscopy, a special side-viewing video endoscope cannulates the Vater's ampulla so that a cholangiogram and pancreatogram can be obtained. The next step is the appropriate therapeutic procedure to deal with the specific problem at hand.

How do common bile duct stones present?
Common bile duct stones are perhaps one of the most frequently seen gastrointestinal (GI) problems. A stone in the common duct will produce biliary pain. The pain is typically felt in the upper abdomen/right quadrant and radiates to the back between the scapulae. At times, it may also present as severe chest pain and could be confused with cardiac pain. Symptoms often occur in patients with previously undiagnosed gallstone disease. However, the pain may arise even after a cholecystectomy, and it's not unusual for patients to say that it feels very much like a previous gallbladder attack, despite having had their gallbladder removed.

The crucial difference between a gallbladder attack and a common bile duct stone episode is that the stone in the common bile duct generates signs and symptoms of a common duct obstruction. On the other hand, acute cholecystitis, resulting from a stone obstructing the cystic duct, produces gallbladder tenderness, both clinically and via ultrasound, with features of gallbladder wall thickening, in addition to fluid collection around the gallbladder. Typically, there are no signs or symptoms of common bile duct obstruction in acute cholecystitis.

Pain may be associated with jaundice, though not always. In a patient who is not jaundiced, the liver enzymes — aspartate aminotransferase (AST), alanine aminotransferase (ALT) and alkaline phosphatase — are elevated. This obstruction can further be complicated by a biliary tract infection (i.e. acute cholangitis) or pancreatic inflammation (i.e. acute pancreatitis) because they share a common channel. In this situation, patients are often in severe pain and require opioid analgesics in the emergency department. Some patients with acute cholangitis, particularly the elderly, may have no pain at all and the major clinical presentation can be fever, septic shock, confusion or heart failure.

Where does an initial evaluation begin?
If common bile duct stones are suspected, order a complete blood count (CBC). If the white blood cell count (WBC) is elevated, consider a diagnosis of acute cholangitis. Other blood work should include liver enzymes — AST, ALT and alkaline phosphatase, which are invariably elevated. If the pancreatic enzyme, lipase/amylase, is elevated (typically in the 1,000s), consider a diagnosis of acute pancreatitis.

An ultrasound examination may demonstrate gallstones, a dilated biliary tree (because of a stone obstructing the duct) and a swollen pancreas in the case of pancreatitis. Keep in mind that in the majority of patients, the actual stone in the common bile duct doesn't show up on ultrasound. Consequently, it's important to rely on other indicators to make a diagnosis.

How are they managed?
Pain relief is the first, and foremost therapeutic step and usually requires opioid-type analgesics. For acute cholangitis, broad-spectrum antibiotics are invariably effective. A minority of cases don't respond to antibiotics and require urgent endoscopic intervention to drain the obstructed biliary tree — ERCP, sphincterotomy and removal of the stones with basket or balloon sweep extraction. Percutaneous biliary drainage is an option used infrequently — especially when endoscopic therapy isn't feasible.