Endoscopic Therapy - Stents

Stents are special tubes which can be placed across narrowing’s in pipes within the body which either carry blood, food, bile or other fluids from one place to another. In gastroenterology they are commonly used to bypass narrowing’s in the oesophagus, stomach duodenum, colon or bile duct. Wherever a stent is a number of complications may arise, including blockage (due to debris or overgrowth), erosion of surrounding or adjacent tissues, and slippage of the stent from its original position.

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Oesophageal stents are commonly made of metal mesh (titanium is sometimes used), which may be covered in a layer of plastic (covered stents). The commonest indication for an oesophageal stent is an oesophageal cancer, however they are occasionally placed for more benign (non cancerous) strictures. Oesophageal Stents can vary in length depending on the length of the narrowing into which they are placed. They usually have a “shoulder at either end which secures them within the narrowing. Whilst they do relieve difficulty swallowing it is not recommended to eat entirely normally with a stent, since meat and bread may get stuck causing further dysphagia. For this reason soft diet is often advised. Once an oesophageal stent has been placed some stents will have a mechanism by which there position can be adjusted post deployment. However this does not amply to all stents, can be challenging and if attempted is usually easier within a few days of stent placement. Uncovered stents are less often if ever used in the oesophagus.

Chronic pancreatitis, gastric and duodenal stents work in a similar way and are often used to relieve outlet obstruction in the setting of gastric or duodenal cancer.

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Pancreatic stents may be inserted at ERCP in patients with pancreatic strictures and chronic pancreatitis. In the setting of necrotic pancreatitis and pancreatic pseudocysts large bore gastrocystostomy stents (such as axios) are used to place a drain from large pancreatic cysts into the stomach. This is a very specialist procedure only undertaken in a few centres.

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Biliary stents are used in a number of settings including benign bile duct strictures, in which case removable plastic stents are often used, bile duct stone disease (choledocholithiasis) where a stent known as a Pig-tail stent (because it has curly ends) is usually used