What Is A Metal Stent in The Biliary Duct?

A metal stent placed in the biliary duct is used to relieve a blockage or narrowing (stricture) of the duct. Some key points about biliary metal stents:

The biliary duct carries bile from the liver to the small intestine. It can become obstructed by stones, tumors, scarring, etc.

A metal stent is delivered via endoscopy into the site of narrowing/blockage in the bile duct. It is self-expanding so it pushes open the stricture.

Common materials used are stainless steel or nitinol (nickel-titanium alloy), giving rigidity to hold the duct open.

A biliary metal stent bypasses the obstruction to restore bile drainage from the liver to the intestine. This relieves jaundice and helps prevent infections.

For cancer-related blockages when longer patency is needed, metal is preferable to plastic stents which clog faster.

Stents may be placed temporarily to drain bile pre-surgery or on an ongoing basis if the blockage is permanent from advanced cancer.

Placement is usually done by gastroenterologists under imaging guidance like fluoroscopy or ultrasound.

So in summary, a biliary metal stent mechanically dilates a blocked bile duct to restore the flow of bile via an endoscopic procedure.