Biliary System
Biliary system that transport bile (a substance that helps in digestion) from liver to intestine. It has two components , one is intrahepatic ( inside the liver)and another one is extra hepatic( outside the liver).It stores bile temporarily to gall bladder during its transport to duodenum . It is related to vital structures like portal vein, hepatic artery ( that carries blood to liver),pancreas & duodenum .
Common diseases of Biliary System :
Bileduct Stone (Choledocholithiasis)
Choledocholithiasis is the presence of gallstones in the common bile duct. This condition causes biliary obstruction leading to jaundice and liver cell damage. It may also cause gallstone pancreatitis and cholangitis (Inflammation of Biliary system).
About 15% of people, gallstones develop in the common bile duct. However, stone( s) may migrate from gall bladder or liver to the bile duct.
The common symptoms are recurrent episodes of abdominal pain, fever and fluctuating jaundice associated with itching. During the attack urine is high colored and stool is pale. Repeated attacks of cholangitis might cause septicemia and impaired kidney function (Hepato renal syndrom)
The diagnosis of choledocholithiasis is suggested when the liver function test shows an elevation in bilirubin and serum alkaline phosphatase. In prolonged cases the INR may change due to a decrease in vitamin K absorption. (It is the decreased bile flow which reduces fat breakdown and therefore absorption of fat soluble vitamins)
The diagnosis is initially made by abdominal ultrasound, which might show dilated bileduct with ehogenic shadow(s) at its lumen. Magnetic resonance cholangiopancreatography (MRCP) , a non- invasive procedure can delineate the whole biliary system and locate the site of stone. Endoscopic Retrograde Cholangio Pancreatography ( ERCP), an invasive procedure is done to diagnose the position of stone, which can also be removed at the same time. When there is associated cholelithiasis , then cholecystectomy ( laparoscopic/open) to be done to prevent a future occurrence of common bile duct stone or other complications
However, ERCP, has its own potential complications and limitations. Removal of stone by ERCP may not be possible if there is narrowing of the distal bileduct, large impacted stone, anomalous opening of ampulla or narrowing of duodenal channel causing difficulty in passing and manipulating the endoscope. At that time stone in the bile duct is removed by open surgery ( choledocholithotomy). Bile duct is opened, stone(s) removed, the distal and proximal biliary channel checked for complete clearance and free passage of distal bile duct is ensured. One tube ( T- tube) placed in the bile duct which is subsequently removed in the postoperative period.
When there is extreme narrowing of distal bile duct or grossly dilated bileduct, then biliary enteric anastomosis ( Roux-en Y hepatico Jejunostomy) , a form biliary reconstruction to be done to ensure the uninterrupted bile flow from liver to intestine.
Bile duct injury :
Bile duct injury is a severe and potentially life-threatening complication of laparoscopic and open cholecystectomy.
Multiple factors are involved in causation of injury. The common factors are developmental anomaly of biliary system, unclear anatomy of the region, severe inflammation and technical difficulties.
Biliary injury immediately may lead to bile leak, bile collection (biloma), peritonitis and septicaemia.
Accidental Clipping/ligation of bile duct may lead to biliary obstruction, heptic failure, coagulation disorder and renal failure .Delayed effect of biliary obstruction is the biliary stricture(narrowing) of bile duct. If this obstruction persists for longer period then causes cholestatic jaundice and finally secondary biliary cirrhosis.
Evaluation needs proper history , liver function, coagulation and renal functional profile, Imaging like abdominal ultrasound, ERCP and MRCP to definite the site and extend of injury. Special emphasis is given to evaluate injury of other structures like vascular and bowel.
Treatment is the restoration hepato enteric bile flow. Endoscopic procedure as ERCP is perfomed for evaluation and stenting the injured site. The surgical procedure depends on the grade of injury, the common practice is the biliary reconstruction (Roux en Y hepaticojejunostomy)
Conclusion
Early recognition and an adequate multidisciplinary approach are the cornerstones for the optimal final outcome. Suboptimal management of injuries often leads to more extensive damage to the biliary tree and its vasculature. Early referral to a tertiary care center with experienced hepatobiliary surgeons would appear to be necessary to assure optimal results.
Biliary stricture:
A biliary stricture is an abnormal narrowing of the common bile duct.
A biliary stricture is often caused by surgical injury to the bile ducts. For example, it may occur after surgery to remove the gallbladder (Cholecystectomy).Other causes of this condition include: damage and scarring due to a gallstone in the bile duct, Pancreatitis, Primary sclerosing cholangitis. Finally it may be due to Cancer of the bile duct.
Narrowing of the biliary duct causes infection above the narrowed area. Long-standing strictures can lead to fibrosis of liver called secondary liver cirrhosis
The common Symptoms are abdominal pain on the upper right side,chills,fever, Itching, Jaundice,nausea ,vomiting , pale or clay-colored stools and high coloured urine.
The following tests can help diagnose this condition: Abdominal ultrasound , Endoscopic retrograde cholangiopancreatography (ERCP), Magnetic resonance cholangiopancreatography (MRCP)
The following blood tests can indicate biliary obstruction: Bilirubin level and Alkaline phosphatase (ALP) are higher than normal. Increased prothrombin time (PT) is suggestive of coagulopathy.
Treatment
The goal of treatment is to correct the narrowing so that bile flow normally from the liver into the intestine. In some cases, a stent (a tiny metal or plastic mesh tube) is placed across the bile duct stricture to keep it open.
The definitive treatment is to remove the stricture part of bile duct followed by joining of bile duct with intestine ( Roux -Y- hepatico jejunostomy) .
Choledochal cyst :
Choledochal cysts represent congenital disproportionate cystic dilatations of the biliary tree. Choledochal cysts are rare, with an incidence of 1 : 100000 – 150000. Although they may be discovered at any age, 60% are diagnosed before the age of 10 years . There is a strong female predilection with a M : F ratio of 4 : 1. There is a greater prevalence in East Asia.
Classically presentation includes the triad of : abdominal pain, jaundice, abdominal mass.This triad is however only present in 19 – 60% of cases
Their aetiology is uncertain but a close association with anomalous formation of the pancreaticobiliary ductal junction is reported.
Imaging of the biliary tree can be achieved with ultrasound, CT direct contrast studies , MRCP or ERCP.
Key to the diagnosis is a dilated cystic lesion which communicates with the bile duct.The two most frequent complications of choledochal cysts are stone formation and malignancy. Stone formation ( most common),malignancy (cholangiocarcinoma) – life time incidence 10 – 15%, cyst may rupture leading to bile peritonitis and may also cause pancreatitis
Treatment is complete surgical excision of choledochal cyst with reconstruction with Roux-en-Y hepaticojejunostomy .
Bileduct cancer :
Bile duct cancer (cholangicarcinoma) is a serious condition . It can happen in the part of the bile duct that is outside or inside the liver. Cancer of the bile duct outside of the liver is much more common. Risk factors include inflammation of the bile duct, older age, some liver diseases, and exposure to certain chemicals.
Cancerous tumors of the bile ducts are usually slow-growing and do not spread (metastasize) quickly. However, many of these tumors are already advanced by the time they are diagnosed. It occurs in approximately 2 out of 100,000 people. Risks for this condition include: Bile duct (choledochal) cysts, anomalous pancreatobiliary junction, Chronic biliary inflammation (cholangitis), infection with the parasitic worm, liver flukes, Primary sclerosing cholangitis and Ulcerative colitis
Symptoms include: Jaundice, Itchy skin, fever, abdominal pain and weight loss
Bile duct cancer is diagnosed by initial investigation as abdominal ultrasonogram,Serum bilirubin,Serum Alkaline Phosphatase, tumour marker like CA 19-9. Imaging like MRCP & CT scan will evaluate the extent of disease. ERCP is made done for diagnostic( site & extent) and therapeutic intent for placement of endoprosthesis to relieve jaundice. Endoscopic brush cytology is helpful for sampling the cancerous lesion of the bile duct.
Possible Complications are Infection (cholangitis),Septicaemia, Liver failure Spread (metastasis) of tumor to other organs
Treatment is mainly surgery in the form of radical resection .Which may include resection of not only bile duct but also part of liver. It follows the anastmosis of bile duct with intestine( biliary reconstruction) .
If not possible then palliative by pass procedure is needed . However endoscopic procedure as temporary or permanent stenting may be done to relieve the obstruction of bile . Radiation therapy and chemotherapy have limited role.
