One of the normal functions of the liver is to produce bile which is important for digestion. The bile drains from the liver to the bowel through a series of small tubes or ducts. If the bile duct becomes blocked, then bile cannot drain normally and jaundice (yellowing of the skin) develops.
To treat the jaundice, the bile needs to be drained from the liver. This can be done by either inserting a drain to externally drain out the bile or placing a stent through the blockage to open it up. The PTC is the process of taking pictures of the bile ducts to see where the blockage might be.