Cholangiograms are imaging techniques that allow a doctor to look specifically at the ducts that release bile into the digestive system. Some of these techniques require the insertion of a small tube into the ducts as part of the procedure. This tube is called a cholangiogram catheter.
Some medical conditions, such as gallstones and cancers, can cause blockages or other problems in the bile ducts. Instead of having to undergo exploratory surgery so the doctor can identify the presence and cause of duct issues, a patient now needs only to have a minimally invasive imaging technique performed. Two major types of imaging procedures on bile ducts necessitate the use of cholangiogram catheters.
A catheter is a specific form of tubing for medical purposes. It allows fluid to either drain out of the body or to enter the body. In the case of a cholangiogram catheter, the fluid needs to go into the body at a specific point. Usually, with cholangiograms, the catheters are narrow in diameter.
This fluid is a dye. The dye shows up on the final image from the imaging technology and helps to identify areas of concern. A blocked duct, for example, will not let dye through, and so the dye will only show up on one side. The dye can help the doctor to pinpoint blockages, leaks, or abnormally narrow ducts that could indicate disease.
Endoscopic retrograde cholangiopancreatography (ERCP) is one imaging technique that uses a cholangiogram catheter. For this procedure, a doctor inserts a camera on a long tube down the digestive system into the top of the small intestine. A thin cholangiogram catheter is then placed directly into the major bile duct. Then, dye is run through the catheter to highlight the area of interest.
Percutaneous transhepatic cholangiography (PTC) is a more invasive procedure that involves insertion of a needle into the abdomen and into the bile ducts. This needle is used as a guide wire for the catheter tube, which slides over it for exact placement. Then, the doctor infuses dye through the catheter into the ducts and highlights the areas of interest with the flow of the dye.
Both the ERCP and the PTC cholangiogram catheters are temporarily inserted as delivery systems for the dye. After the procedures, the catheters are removed. As well as the ERCP and PCT techniques, magnetic resonance imaging can also find duct problems, and this technique does not require any dye insertion or invasive tube insertion.