Endoscopic retrograde cholangiopancreatography.

Endoscopic retrograde cholangiopancreatography (ERCP) involves cannulation of the papilla of Vater followed by contrast radiology of the biliary and pancreatic ducts. With experience, X-ray films of the desired duct(s) can be obtained in 90% of patients, with minimal patient discomfort and a low frequency of complications. Retrograde cholangiography accurately assesses the site and cause of biliary tract obstruction. Retrograde pancreatography reveals ductal abnormalities in most patients with chronic pancreatitis and pancreatic cancer, and the nature of the abnormality usually permits differentiation of the two diseases. The diagnostic accuracy of ERCP is enhanced by cytological evaluation of pure pancreatic juice, while endoscopic sphincterotomy is a therapeutic option in selected patients with choledocholithiasis and papillary stenosis. Current developments include endoscopic aspiration biopsy of the pancreas and endoscopy of pancreatic and biliary ducts, using a miniature endoscope passed down a channel in the parent instrument.