Stents are devices that create space when a duct or vessel has become obstructed. An enteral stent is a type of stent that is inserted in the digestive tract if you have a growth creating an obstruction in the esophagus, stomach, small intestine or colon. Your doctor may suggest an enteral stent for two reasons:
—Enteral stents are often used to treat malignant obstructions. In advanced colorectal disease or esophageal cancer, doctors may recommend a stent when surgery, chemotherapy and radiation are no longer the best option. In patients with esophageal cancer, stenting provides relief of dysphagia (difficulty swallowing) in 95 percent of patients. For patients with colorectal cancer, enteral stents create space in an obstructed bowel so that stool can pass. The goals of stents in palliative care are management of symptoms and improved quality of life.
—Enteral stents can also be used as a temporary treatment to alleviate a blockage in the colon. Often, an obstruction in the colon would require immediate surgery, but a stent could convert an emergency procedure into an elective procedure and could prevent the need for a colostomy. If you are at increased risk for complications as a result of emergency surgery, an enteral stent could be the preferred method of treatment for you. Studies have shown that colonic stent insertion followed by elective surgery is more effective and less costly than emergency surgery.
The use of enteral stents has expanded to the treatment of benign digestive conditions as well, such as strictures, bleeding varices and fistulas in the gastrointestinal tract.
Types of stents
Rigid plastic stents were the only type of stents available until the 1990s, and complication rates were significant. Now, there are self-expandable metal stents (SEMS), self-expandable plastic stents (SEPS), and biodegradable stents.
The enteral stent is a self-expandable metal stent. SEMSs are made of woven, knitted or laser cut metal mesh cylinders that exert self-expansive forces until they reach their maximum diameter. Both ends of the SEMSs are flared to prevent movement after they have been placed. They are packaged in a compressed form and are contained in a delivery device. Some SEMSs are covered or partially covered by plastic or silicone to prevent the tumor from growing into the mesh, but enteral stents are currently manufactured uncovered.
Before the Procedure
Your doctor will assess the length of your stricture and the degree of obstruction by endoscopy, computerized tomography (CT), barium enema, radiography or fluoroscopy. The stricture will be marked from end to end and measured. It is important to have a stent that is longer than the stricture so there is less risk of stent movement (migration).
If you have a complete colon obstruction, you may need to take prophylactic antibiotics before your enteral stent procedure because the introduction of air during the procedure could cause infection and microperforation. If you have a partial obstruction, you may need to prepare your bowel with one or two enemas or a full colonoscopy prep.
You will need to provide your doctor with a list of all your current medications, and you will be notified if there are any medications you should stop taking before your procedure.
On the day of the procedure
You should plan to have someone drive you to and from your procedure because you will be sedated and your faculties will be impaired. When you arrive at the surgery center, you will be given mediation through an IV to relax you.
During the Procedure
The operating room will be equipped with fluoroscopy (continuous x-ray image on a monitor) which will allow your doctor to view the obstruction on a screen.
Your doctor will place your enteral stent by endoscope or colonoscope with a specialized working channel using a method called TTS Placement (Through The Scope Placement). Your doctor will use the scope to identify your obstruction and will insert a guidewire through the obstruction. Once the guidewire is in position, the stent is passed over the guidewire and placed at the site of the obstruction. Once the stent is positioned across the stricture, radial forces anchor it in place.
Your doctor will use the fluoroscope to carefully inspect the stent to make sure that the ends of the stent are flared and fully expanded to make a “waist.” If the stent is too short, another stent may overlap the first stent to fully open the stricture.
The duration of the procedure will vary according to how difficult it is to access the obstruction. Stent insertion usually takes at least one hour.
After the Procedure
You will be taken into a recovery area for monitoring as your sedative wears off. For several hours after your procedure, you should only consume clear liquids. If you have a stent inserted for an esophageal obstruction, you will need to alter your diet. The texture of your food needs to be moist and soft to go down your esophagus easily. Some good examples of soft foods would be scrambled eggs, applesauce or cream of wheat. It is important that you chew all food thoroughly, take small bites, and remain in an upright position at least 30 to 60 minutes after eating.
Successful stent placement should bring immediate results. If you have an esophageal obstruction, you should be able to swallow with ease. For a colon obstruction, you should be able to pass stool and gas shortly following the procedure.
Risk Factors of Enteral Stent
Initial risk factors of enteral stents may include:
- Tracheal compression
Later complications may include:
- Stent migration
- Tumor ingrowth
Enteral stents are a successful solution for palliative care in cancer patients and preoperative decompression for individuals who would otherwise need emergency surgery. Stenting has been proven to be safe and successful for all age ranges and has expanded into the realm of benign strictures. It is certain to expand further as biodegradable stents and drug-eluting stents are studied and developed.