Stenting

Definition

Stenting is a procedure in which a cylindrical structure (stent) is placed into a hollow tubular organ to provide artificial support and maintain the patency of the opening. Although it is most often used for cardiovascular functioning, it is also utilized to manage obstructions in cancer patients.

Purpose

Stents are used in cancer patients to relieve obstructions due to:

  • direct blockages within the tube (or lumen) due to cancer growth
  • narrowing of the lumen from tumor growth outside pressing on the tube and narrowing the lumen
  • occasionally from the build up of scar tissue (fibrosis) from radiation therapy

Tumors most likely to cause obstruction requiring stent placement include esophageal cancer, bronchogenic carcinoma, pancreatic cancer, cancers of the bile duct, and occasionally colorectal carcinomas.

Precautions

Every patient should be viewed individually with special consideration given to the patient's present status. Generally, surgical procedures are for the correction of a problem; but in many cancer cases, relief of symptoms is the only therapeutic option. Since it is extremely difficult to remove or reposition these stents after they are placed, the degree of relief to be offered by its insertion should be significant. The physician and the patient should discuss all alternatives and come to a mutual decision.

Description

Endoscopic retrograde cholangiopancreatography (ERCP) is the name of the procedure utilized to place most stents for pancreatic and biliary tumors. The ERCP is a flexible endoscope, which can be directed and moved around the many bends in the upper gastrointestinal tract. The newer video endoscopes have a tiny, optically sensitive computer chip at the end which transmits electronic signals up the scope to a computer that displays an image on a large video screen. The scope has an open channel that permits other instruments to be passed through it to perform biopsies, inject solutions, or place stents. Since ERCP uses x-ray films, the procedure takes place in an x-ray area. Initially the throat is anesthetized with a spray solution and the patient is also usually mildly sedated. The endoscope is inserted into the upper esophagus and a thin tube is inserted through it to the main bile duct entering the intestinal area. Dye is injected into the bile duct and/or the pancreatic duct and x-ray films are taken. The patient usually lies on the left side and then turns onto the stomach to allow complete visualization of the ducts. The patient is able to breathe easily throughout the exam and rarely gags. Any gallstones found may be removed or if the duct has become narrowed, an incision can be made using electrocautery (electrical heat) to relieve the blockage. It is also possible to widen narrowed ducts by placing stents in these areas to keep them open. The patient is taken to recovery following the procedure, which takes 20-40 minutes.

Other endoscopes are used to place stents elsewhere in the body. For example, an esophagoscope is used to place stents in cases of esophageal cancer, a broncho-scope is used for procedures involving endobronchial obstructions, and a colonoscope is used in cases of colorectal obstructions.


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