Definition and Overview
Biliary stricture, also known as bile duct stricture, is a condition wherein the common bile duct becomes abnormally narrow.
The common bile duct is part of the biliary system. It is a tube-like structure and its main function is to move bile from the liver to the small intestine where bile aids in digestion by helping break down fats into fatty acids.
When bile flow is obstructed due to this condition, bile builds up in the liver resulting in the increased amount of bilirubin in the blood. This leads to jaundice, infection, and fever.
Causes of Condition
Biliary strictures can be benign (non-cancerous) or malignant (cancerous). Most benign cases are a result of accidental injuries during certain surgical procedures that involve structures in close proximity to the common bile duct. These operations include:
Cholecystectomy - A surgical procedure that removes the gallbladder. It accounts for up to 80% of all benign biliary stricture cases.
Gastrectomy - A surgical procedure that removes part or the entire stomach.
Hepatic surgery - The surgical removal of part or the entire liver.
Surgical complications that lead to the development of strictures are usually caused by inexperienced surgeons, congenital anomalies, misplaced clips, excessive cauterisation, and excessive bile duct dissection.
Other biliary strictures causes (some of which are associated with malignant strictures) include:
Cancer of the liver or bile duct
Cancer of the pancreas – Pancreatic cancer is considered as the most common cause of malignant biliary strictures.
Scarring or organ damage caused by gallstone in the bile duct
Primary sclerosing cholangitis – A disease that causes strictures as well as other irregularities in the intra and extrahepatic bile ducts, commonly due to inflammatory bowel disease.
Liver transplantation – Up to 50% of biliary complications that occur after a liver transplant are due to biliary anastomotic strictures. Some form a few months after the procedure, while others after several years. The risk of stricture formation mostly depends on the reconstruction technique used such as duct-to-duct anastomosis, choledochojejunostomy, or T-tube.
Biliary strictures form when the above factors trigger an inflammatory response in the body. This causes collagen deposits to develop along the bile ducts resulting in the formation of strictures that eventually narrow the duct.
Depending on the severity of the narrowing of the common bile duct, patients may experience the following biliary strictures symptoms:
Fever, which can be caused by an infection brought about by the stricture
Obstructive jaundice – A type of jaundice wherein the intestine is blocked, causing the bile to remain in the bloodstream.
Patients who present with these symptoms should undergo a medical check-up that includes the following diagnostic tests:
Magnetic resonance imaging (MRI) scan
Percutaneous transhepatic cholangiogram (PTC) - The imaging of the bile duct using an x-ray technology
Alkaline phosphatase (ALP) test – Measures the amount of the enzyme ALP in the blood. A patient with a problem involving the biliary system will have higher than normal levels of alkaline phosphatase.
Bilirubin test – A patient with a biliary system issue will have heightened levels of bilirubin, a substance found in bile and produced when the liver breaks down old red cells.
Once diagnosed, strictures need to be treated or removed immediately. When left untreated, they can eventually cause serious health problems, such as liver damage or liver cirrhosis.
Due to the urgent nature of this condition, patients are usually admitted to the hospital upon diagnosis, especially if they are showing signs of an infection. In severe cases where the patient is showing symptoms of ascending cholangitis (the inflammation of the bile duct system usually due to a bacterial infection), intensive care may be required, especially if hypotension is also observed and if the patient’s mental state has already been affected.
Patients who suffer from malignant biliary strictures face a greater risk of life-threatening complications (such as tumour invasion, metastasis, and portal hypertension) than those who have benign strictures. In fact, records show that more patients succumb to such complications rather than to the stricture itself.
Who to See and Types of Treatments Available
Patients suffering from the symptoms of a biliary stricture should see their family physician or general practitioner for tests. If diagnosed with a biliary problem, they are referred to biliary and pancreatic disease specialists, surgeons (if surgical therapy is required), or interventional radiologists (who can now treat biliary strictures using radiology-based treatments).
The primary goal of biliary stricture treatment is to repair the narrowed part of the bile duct to restore normal bile flow. Depending on the severity of the condition, this can be done surgically or through medical therapy that mainly involves antibiotics. If the patient's condition does not respond well to antibiotics, the biliary tree may be drained and decompressed to achieve better results.
In cases where medical therapy is no longer promising, surgery becomes the only option. Fortunately, a biliary stricture can now be surgically treated in a minimally invasive manner in which the bile duct is dilated using an endoscope, a flexible tube with a light and camera attached to it.
If traditional open surgery is preferred, the surgeon will make an incision in the abdomen to remove the part of the bile duct where the stricture is found. The two loose ends are then reconnected to the small intestine. If the stricture is removed percutaneously, the surgeon will put a tiny mesh tube called a stent across the bile duct to keep it open and prevent obstruction.
Patients undergoing treatment for biliary strictures face certain risks, such as inflammation and infection. Despite this, most cases are successfully treated. However, the long-term prognosis of patients depends on the specific cause of the stricture. In some cases, the strictures may recur even after surgery.
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Shanbhogue AKP, Tirumani SH, Prasad SR, Fasih N, McInnes M. “Benign biliary strictures: A current comprehensive clinical and imaging review.” American Journal of Roentgenology. 2011; 197: (2)W295-W306. http://www.ajronline.org/doi/abs/10.2214/AJR.10.6002
Villa NA, Harrison ME. “Management of biliary strictures after liver transplantation.” Gastroenterol Hepatol (NY). 2015 May; 11(5): 316-328. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4962682/