Dilation Flashcards
What are the two types of dilation?
- Fixed-Diameter / Rigid / Push Dilators / Non-Thru-The-Scope - The diameters of these dilators are too large to fit through the working channel of an endoscope
- Radial Expanding / Pull Dilators - These are balloons that are introduced thru-the-scope.
They use air or liquid pressure to expand to predetermined diameters.
Why do we dilate?
Dilation is a procedure that is used to open narrowed areas or strictures in the GI tract.
- Restore a patient’s ability to eat and drink normally.
- Allow access for additional procedures (stents).
What are examples of Radial Expanding Dilators?
Balloon dilators may be inflated with water (hydrostatic) or air (pneumatic):
Hydrostatic balloons: Used in any accessible region of the GI tract. Pressure-injected liquid (e.g., water, radiopaque contrast) expands the balloon to the specified diameter.
Pneumatic balloons: Used specifically for achalasia (a condition, caused by nerve damage, that makes it difficult for food and liquid to pass into the stomach). These balloons have a larger expanded diameter than hydrostatic balloons and are not delivered through the endoscope.
What are examples of Rigid dilators? (push dilators)
Bougienage (“Bougies”): Weighted mercury or tungsten-filled tapers that do not provide any method for visualization. These are typically used for esophageal strictures.
Savary-Gillard (“Savary”): Wire-guided tapered polyvinyl chloride dilators with a semi-flexible lumen for a guidewire.
What is the rule of 3?
The “rule of three” in dilation of esophageal strictures recommends that, in a single session, no more than three dilators of sequentially larger size should be passed once moderate or greater resistance is evident. Dilators passed with no or mild resistance do not count toward this total.
You can cause perforation if you dilate too much, too fast
Explain the difference between radial & axial force? Which do balloons use?
“Radial” force is force applied inside and out. It is equally and simultaneously delivered the full length of the stricture. Balloons use radial.
Axial force is applied to a dilator externally. You can visualize a stricture squeezing the dilator. Bougies use this type of force. With extreme external pressure, the dilator may bend or break.
What are potential dilation complications?
Perforation: Internal puncture or tearing may occur during the procedure. A typical site of perforation is proximal to a stricture. Perforation can often be managed using suction and antibiotics.
Minor Bleeding: Small amounts of bleeding may occur during dilation.
Hemorrhage: Uncontrolled bleeding may occur during or immediately following the procedure.
Aspiration: Aspiration of oral secretions or food matter may occur into the airway during a dilation procedure.
Infection: An infection may develop in or around the site after dilation. Bacteremia (or bacteria in the blood) presents a serious problem for immune-compromised patients or patients with prosthetic valves.
What are common areas where stricures form?
Esophagus, Pylorus, Colon
Can you dilate malignant stricures?
You can dilate both benign and malignant strictures.
Cases of esophageal cancer may also be treated with dilation. An adenocarcinoma or squamous cell carcinoma of the esophagus may be caused by Barrett’s esophagus, excessive smoking or use of alcohol, chronic inflammation of the esophagus, nutritional deficiency, and other reasons. There is a low overall survival rate and treatment is usually palliative.
What is Schatzki’s Ring?
An BENIGN esophageal stricture that results from scar tissue forming a concentric lower esophageal ring in the LES. It narrows the opening of the esophagus to the stomach.
The main symptom of Schatzki’s ring is episodic dysphagia.
The causes of Schatzki’s ring can be:
* Congenital defect
* Chronic injury due to GERD
* Ingestion of caustic material
What are Esophageal Webs?
**BENIGN **small, thin growths of tissue in the esophagus.
They tend to be located in the middle or upper esophagus. The tissue can partially block the esophagus causing intermittent dysphagia.
What is an Anastomotic Stricture?
These can occur anywhere in the GI Tract.
It is a BENIGN stricture that is the result of scarring following a surgical procedure.
Anastomotic strictures may result from surgical procedures for the treatment of:
* Barrett’s esophagus
* GERD
* Achalasia
* Perforation or penetration complications due to peptic or gastric ulcers
* Removal of gastric obstructions
* Morbid obesity
* IBD
* Diverticula disease
* Malignancy
What is Achalasia?
This BENIGN condition is characterized by the loss of the wave-like contractions of smooth muscles called peristalsis that forces food through the digest tract.
Patients with achalasia present with:
* Dysphagia to solids and fluids
* Vomiting
* Regurgitation
* Heartburn
* Weight loss
Why would we dilate in the stomach or pylorus?
Because of the following associated diseases or conditions:
* Ulcers
* Gastric outlet obstruction (GOO)
* Gastric cancer
* Pancreatic cancer
Why would we dilate in the colon?
Because of the following associated diseases or conditions:
* Inflammatory bowel disease (IBD)
* Colorectal cancer
