What is the Liver and the Biliary Tree?
The liver is the largest solid organ in the body. It is located in the right upper part of the abdominal cavity, below the breathing muscle (diaphragm), and behind the rib cage. It is surrounded by multiple vital organs, the stomach lies on its left, the gallbladder sits just below the edge of the liver on the right, and the small and large intestines travel along its lower border. The liver is made of two parts, a bigger right lobe and a smaller left lobe. The liver is connected to the intestines through a conduit called the common bile duct. The gallbladder that has a function of storing bile is also connected to the common bile duct via the cystic duct.
The liver is responsible for a plethora of vital functions, including but not limited to detoxification of body wastes, production of essential nutrients for body function, it produces bile that helps with fat digestion, it has a very important role in immunity, and it produces clotting factors to prevent bleeding. Bile is produced by liver cells and get secreted into small channels that connect to larger ducts ultimately becoming the right and left hepatic ducts that merge to form the common hepatic duct. The common hepatic duct merges with the cystic duct to become the common bile duct.
External Anatomy of the Liver and Biliary Tree
Anatomy of the Biliary Tree
The liver get its blood supply though two sources: the hepatic artery and the portal vein. Blood after circulating through the substance of the liver and detoxified, drains into hepatic veins that direct blood back to the heart. These blood vessels and bile ducts divide into smaller branches that supply individual segments of the liver.
There are 8 segments in a human liver. Bile duct surgery aims to remove tumors, strictures or stones causing obstruction of the biliary tree. It is one of the most involving surgeries done in the abdomen and requires skilled specialists in order to be performed safely.
Common Symptoms of Biliary Diseases
Common symptoms depend on the nature of the problem but in general include:
- Abdominal pain: in different areas of the abdomen, most commonly in the right upper side.
- Jaundice: yellowing of the skin and mucous membranes happens when the biliary tree is obstructed and the bile backs up into the liver.
- Weight loss, poor appetite and aversion to food.
- Fatigue, depression.
Treating Biliary Diseases
Biliary diseases that are treated with surgery are usually divided into three categories:
- Gallstones: these are formed in the gallbladder and sometimes travel down the bile ducts and get stuck there. These are usually removed using a minimally invasive procedure called endoscopic retrograde cholangiopancreatography (ERCP). This is an endoscopic test done by your gastroenterologist, usually used to diagnose and sometimes treat blocked bile ducts by placing a stent inside of the duct in order to drain the liver and treat jaundice. Surgery is indicated when ERCP fails to remove stuck stones.
- Benign bile duct strictures: the bile ducts sometimes are scarred down because of surrounding inflammation or pancreatitis and will need surgical correction.
- Pre-cancerous lesions: choledochal cysts are benign cysts of the biliary tree that carry the risk of becoming cancers if left untreated. These are removed by surgery.
- Cancerous lesions: cancer of the bile ducts is called cholangiocarcinoma. Treatment is dictated by the stage of the disease and might involve surgery, transplantation, chemotherapy, or radiation therapy.
Surgery of Biliary Liver
The extent of surgery of the biliary tree is dictated by the location of the disease, and whether the lesion is benign, malignant or pre-malignant. Biliary surgery is one of the biggest and most involving surgeries in the abdomen, and that is due to the proximity of the bile ducts to vital organs, in addition to important blood vessels.
It is usual to have the gallbladder removed at the time of biliary surgery for many reasons that your surgeon will explain during the office visit.
Segmental Resection of Biliary Tree – Biliary Bypass
For some patients who happen to have the disease in the distal portion of the bile duct inside the pancreas, a Whipple procedure is indicated. The classic Whipple procedure is named after Allen Whipple, who was the first surgeon to perform the operation in 1935. The procedure is also known as pancreaticoduodenectomy, and it involves removal of the head of the pancreas, the first part of the small intestine (duodenum), in addition to a part of the bile duct, gallbladder, and a small part of the stomach. The pancreas, bile duct and the stomach are then reconnected to the intestines.