The common bile duct (CBD) is the tubethat connects gall bladder to the upper part of the small intestine (the duodenum). The function of CBD is to carry bile from the gallbladder and empty it into the duodenum. CBD is the distal continuation of the common hepatic duct, the tube that carries bile from the liver to the gall bladder.
Gall bladder along with its duct (cystic duct), common hepatic duct, and CBD comprises of the ‘biliary system’.
Presence of stones in CBD is known as CBD stones or choledocholithiasis. There are two mechanisms of CBD stones:
Symptoms of choledocholithiasis include pain in the upper abdomen, jaundice, and occasionally fever. The presence of fever indicates the presence of infection in the bile ducts known as cholangitis, which is life threatening. Rarely the CBD stone may also obstruct the opening of the pancreatic ductbecause these ducts are usually connected.This may cause acute pancreatitis, which is another serious disease manifesting as severe pain, vomiting, fever, and distension.
CBD stoneshave to be physically removed and there is no medicine or drugs that can remove or dissolve these stones. The physical removal of CBD stones may be accomplished either by endoscopic method (with or without lithotripsy) or by surgical method (traditional or laparoscopic).
The most widely used method for treating CBD stones is their endoscopic removal by ‘endoscopic retrograde cholangiopancreatography (ERCP)’. A special type of endoscope known as side-viewing endoscope is introduced through the mouth and its tip is positioned in the first part of small intestine (duodenum) near the opening of CBD. From the tip of endoscope a catheter is introduced into the CBD through which a dye is injected. This dye opacifies the entire CBD as seen by fluoroscopically, and the stone becomes visible as filling defect in the CBD. Subsequently a wire basket is introduced in the CBD which catches the stones and brings it out of CBD into the duodenum from where it can be taken out. To aid the extraction of stone from the CBD a small cut is made at the opening of CBD to enlarge it so that stone can be extracted easily. To completely clear the CBD a special balloon is sweeped in the CBD to remove any stone particles.
Lithotripsy physical breaking of stone.The term is derived from the Greek words meaning "breaking (or pulverizing) stones". If the CBD stone is large it cannot be extracted from CBD in one piece and has to be broken into pieces using lithotripsy so that these pieces can be extracted easily by ERCP. There are many types of lithotripsy procedures as given below, and depending on the need and availability any one of them can be used for removal of large stones:
When CBD stones cannot be removed endoscopically, they have to be removed surgically. The advantage of surgical treatment is that both CBD stones and gall bladder stones can be taken care of in one stage. Most commonly laparoscopic approach is applied.