Endoscopic retrograde cholangiopancreatography


Endoscopic retrograde cholangiopancreatography is a technique that combines the use of endoscopy and fluoroscopy to diagnose and treat certain problems of the biliary or pancreatic ductal systems. It is primarily performed by highly skilled and specialty trained gastroenterologists. Through the endoscope, the physician can see the inside of the stomach and duodenum, and inject a contrast medium into the ducts in the biliary tree and pancreas so they can be seen on radiographs.
ERCP is used primarily to diagnose and treat conditions of the bile ducts and main pancreatic duct, including gallstones, inflammatory strictures, leaks, and cancer.
ERCP can be performed for diagnostic and therapeutic reasons, although the development of safer and relatively non-invasive investigations such as magnetic resonance cholangiopancreatography and endoscopic ultrasound has meant that ERCP is now rarely performed without therapeutic intent.

Medical uses

Diagnostic

The following represent indications for ERCP, particularly if or when less invasive options are not adequate or definitive:
stone seen at the time of ERCP. The stone is impacted in the distal common bile duct. A nasobiliary tube has been inserted.
ERCP may be indicated in the above diagnostic scenarios when any of the following are needed:
The patient is sedated or anaesthetized. Then a flexible camera is inserted through the mouth, down the esophagus, into the stomach, through the pylorus into the duodenum where the ampulla of Vater exists. The sphincter of Oddi is a muscular valve that controls the opening to the ampulla. The region can be directly visualized with the endoscopic camera while various procedures are performed. A plastic catheter or is inserted through the ampulla, and radiocontrast is injected into the bile ducts and/or pancreatic duct. Fluoroscopy is used to look for blockages, or other lesions such as stones.
When needed, the sphincters of the ampulla and bile ducts can be enlarged by a cut with an electrified wire called a sphincterotome for access into either so that gallstones may be removed or other therapy performed.
Other procedures associated with ERCP include the trawling of the common bile duct with a basket or balloon to remove gallstones and the insertion of a plastic stent to assist the drainage of bile. Also, the pancreatic duct can be cannulated and stents be inserted. The pancreatic duct requires visualisation in cases of pancreatitis.
In specific cases, other specialized or ancillary endoscopes may be used for ERCP. These include mother-daughter and SpyGlass cholangioscopes as well as balloon enteroscopes.

Risks

One of the most frequent and feared complications after endoscopic retrograde cholangiopancreatograhy is post-ERCP pancreatitis. In previous studies, the incidence of PEP has been estimated at 3.5 to 5%. According to Cotton et al., PEP is defined as a “clinical pancreatitis with amylase at least three times the upper limit of normal at more than 24 hours after the procedure requiring hospital admission or prolongation of planned admission”. Grading of severity of PEP is mainly based on the length of hospital stay.
Risk factors for developing PEP include technical matters related to the ERCP procedure and patient-specific ones. The technical include manipulation of and injection of contrast into the pancreatic duct, cannulation attempts lasting >5 minutes, and biliary balloon sphincter dilation; among patient-related factors are female gender, younger age, and Sphincter of Oddi dysfunction. A systematic review of clinical trials concluded that a previous history of PEP or pancreatitis significantly increases the risk for PEP to 17.8% and to 5.5% respectively.
Intestinal perforation is a risk of any gastroenterologic endoscopic procedure, and is an additional risk if a sphincterotomy is performed. As the second part of the duodenum is anatomically in a retroperitoneal location, perforations due to sphincterotomies are retroperitoneal. Sphincterotomy is also associated with a risk of bleeding.
There is also a risk associated with the contrast dye in patients who are allergic to compounds containing iodine.
Oversedation can result in dangerously low blood pressure, respiratory depression, nausea, and vomiting.
Other complications may include heart and lung problems, infection in the bile duct called cholangitis. Using antibiotics before the procedure shows some benefits to prevent cholangitis and septicaemia. In rare cases, ERCP can cause fatal complications.
Cases of hospital-acquired infections with carbapenem resistant enterobacteriaceae linked to incompletely disinfected duodenoscopes have occurred in the U.S. since at least 2009 per the FDA. Outbreaks were reported from Virginia Mason Hospital in Seattle in 2013, UCLA Health System Los Angeles in 2015, Chicago and Pittsburgh. The FDA issued a safety communication "Design of ERCP Duodenoscopes May Impede Effective Cleaning" in February 2015, which was updated in December 2015.