Esophageal Dilation

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Esophageal stricture

involves abnormal narrowing of the distal portion of the esophagus. It is a relatively common phenomenon, affecting approximately two in 1,000 people. Symptoms of this disorder vary and may include difficulty swallowing (dysphagia), painful swallowing, regurgitation of food and weight loss. Further complications may also arise if the stricture is left untreated. Fortunately, esophageal dilation offers potential relief and healing for those suffering from esophageal stricture.

“The most common way that patients with strictures present clinically, is they get the sensation that something is stuck,” says Kristine Krueger, MD, medical director for the University of Louisville’s Digestive Health Center, and vice-chief of staff at the University of Louisville Hospital. This sensation may be felt anywhere along the length of the esophagus. “They may feel it at the sternal notch, even if the blockage is right behind the breastbone,” continues Krueger. She points out that patients usually do not experience symptoms of dysphagia until their stricture diameter is 13 mm or less. “The normal esophageal diameter should be two to three centimeters, so they can have quite a stricture before theyfre symptomatic.”

There are a number of distinct causes of esophageal stricture. The most common is thought to be reflux esophagitis, in which prolonged exposure to stomach acid and peptic juices injures the esophagus, causing inflammation and scarring. Given the prevalence of reflux esophagitis in the United States, this is a serious concern for those who do not receive treatment. The widespread use of proton pump inhibitors (PPIs) seems to have caused a gradual decrease in these peptic strictures over the last 10 years or so.1 PPIs may also offer a means of protection against recurrence of strictures after dilation has been performed.2

Benign fibrous tissue that forms in a ring on the distal esophagus for unknown reasons may also cause stricture; this is referred to as Schatzki’s Ring. Achalasia is a condition distinguished by spasm or inability of the esophageal sphincter muscles to relax, resulting in blockage. Strictures may also form when caustic agents are ingested or from a burn injury such as inhalation of high heat. A common cause of stricture in children is esophageal atresia, which is a congenital condition characterized by failure of the esophagus to develop properly.

“The other category is malignant strictures,” says Krueger. “Cancers can present as a mass that will give them the same symptoms of dysphagia, so on the differential diagnosis anybody who complains of dysphagia needs to be evaluated for those symptoms.” Krueger notes that weakness, anemia, significant weight loss and dehydration accompanying dysphagia may lead to suspicion of malignant stricture.

Patients experiencing dysphagia or other symptoms that may indicate a possible stricture are often given a contrast study. “Most strictures are seen on a contrast study,” says Ken Lee, MD, FAAP, pediatric gastroenterologist at Children’s Hospital of Wisconsin, and assistant professor of pediatrics and director of pediatric endoscopy for the division of pediatric gastroenterology, Medical College of Wisconsin. Occasionally we’ve had some surprises where a patient might have difficulty swallowing and the contrast study has looked normal and then we’ve gone in and realized there’s a stricture, but the vast majority of the time a contrast study picks it up.” EGD may also be used to establish or substantiate the diagnosis.

After a stricture has been confirmed, esophageal dilation is often considered as the primary treatment option. Balloon dilation is done directly through an endoscope. Balloons can be inflated to sizes from 6 to 30 mm.

“In the case of a known esophageal stricture, the endoscope is placed, we visualize the stricture through the endoscope and then we pass the balloon through the instrument channel while it’s still deflated,” says Lee. “We keep the stricture in the middle of the balloon and then we inflate it to a given diameter.”

The desired diameter is known to have been reached based on the pressure of the balloon. For example, Lee explains that if a balloon is specified to be 18 mm at three atmospheres, the nurse or technician would pump the balloon while using a pressure gauge to measure the pressure until the three atmosphere mark is reached.

Once the balloon has been inflated to the desired diameter, it is kept in place for a short time before deflating. “Some texts say 30 seconds, I actually use two minutes at a time and then deflate it,” says Lee. “We then take the balloon out and look through the endoscope to see what effect it’s had—did it dilate, how much bleeding is there and of course did we cause a perforation, which is always a risk.”

Lee explains that minimal bleeding is a positive sign. “Actually, to achieve a good result with dilation, you do want to see bleeding,” he says. “That means you’ve broken the tissue and stretched the stricture. Occasionally you can have a prolonged bleed, but usually you would know about that during the procedure, especially using endoscopy.”

“It’s a direct visualization, so you can see if you’re causing too much trauma,” says Krueger. “If you’re tearing too fast you can ask your assistant to reduce the pressure and deflate the balloon.” The ability to control and monitor the balloon makes it reliable procedure. “That is the most common type of dilation and it has a very low complication rate with a good success rate,” says Krueger.

A second type of dilation involves the use of bougies, or savaries, which are rigid rubber tubes. Progressively larger bougies are passed through the mouth and down the esophagus using a wire in order to dilate the stricture. The lack of an endoscope during bougie dilation can be a disadvantage. “It is not done under any direct visualization, but it may be done under fluoroscopy, where you would see a shadow in the X-ray, but we don’t have an endoscope down there,” says Lee.

Bougies do have advantages in certain circumstances. “They’re often useful for long strictures,” Lee continues. “If an esophagus is strictured for, say, 10 cm, balloon dilation doesn’t work very well.”

Some literature recommends the so-called “rule of threes” in regard to bougie dilation. According to this rule, the first bougie used should be roughly equal in diameter to the stricture itself. Subsequently, no more than three progressively larger bougies should be passed into the esophagus after the first bougie that encounters moderate resistance. This rule was originally formulated to be used with mercury-filled bougies dilating to no more than 1.3 mm in a single session.3 This rule may be used as a guide, although extensive data verifying its effect on efficacy and safety of dilation does not exist.

In fact, risk of complication using bougies may be higher. “When you bougie somebody, you’re dilating their whole esophagus essentially, so you can tear anywhere along the esophagus because there are shearing forces the whole way,” says Krueger. However, she points out that circumstances and preference dictate which method will be used. “It’s really an individual choice; it depends on a lot of factors such as the length, tightness and cause of the stricture.”

Depending on the circumstances, esophageal dilation can be an inpatient or outpatient procedure. “It depends on the comfort of the endoscopist and the style of the endoscopist or radiologist,” says Lee. “In my experience, most of my cases where I’ve done the balloon dilation, I’ve felt comfortable sending them home.” Level and type of sedation may also factor into length of stay.

Potential complications resulting from esophageal dilation are relatively rare but can be severe. “The most serious complication is a perforation,” says Lee. “Occasionally in an immuno-compromised patient, because you’re putting such trauma on the tissue, there is a risk of septicemia.” Lee adds that this caution may apply to patients with abnormal or artificial heart valves as well. Prognosis can vary depending on the initial cause of the stricture, as Lee explains. “For example, if it’s reflux esophagitis, the standard practice is not only to dilate the stricture, but also to give antacid therapy to reduce the trauma and irritation to the area,” he says. “The prognosis in this case is pretty good.”

This antacid therapy is vital to achieve long-term relief in cases of reflux after dilation has been performed. Krueger points out that recurrence of stricture is probably less than 10 percent for patients who maintain proper medication. “That’s an important issue because if patients don’t take the PPI, they have the same physiology that made them reflux to begin with, and the recurrence rate of strictures from acid is actually high if they do not consider the source, which is acid, and then strongly acid-suppress,” says Krueger. “They do need to be seen in follow-up to see that their symptoms have abated and that they’re taking their medicine and it needs to be stressed that they need to stay on their medication.”


Works cited:

1. Guda NM, Vakil N. Proton Pump Inhibitors and the Time Trends for Esophageal Dilation. Am J Gastroenterol. 99(5):797-800, 2004.

2. Richter JE. Peptic Strictures of the Esophagus. Gastroenterol Clin North Am. 28(4):875-91, vi, 1999.

3. http://www.emedicine.com/MED/topic744.htm


Facts at a Glance

Methods of Esophageal Dilatation

After a diagnosis is made, the physician determines the best method of treatment. A variety of techniques is available; each has benefits and is appropriate in specific cases.

SIMPLE DILATORS (BOUGIES) —
A series of flexible dilators of increasing thickness, the bougie is the simplest and quickest method of opening the esophagus. One or more bougie is passed down through the esophagus at a time.

GUIDED WIRE BOUGIE —
Through endoscopy a flexible wire is placed across the stricture. The endoscope is removed and the wire left in place. A dilator with a hole through it from end to end is guided down the esophagus and across the stricture. One or more of these dilators are passed over the wire. At the end of the procedure, the wire is removed. This type of treatment may be performed in the x-ray department under fluoroscopy.

BALLOON DILATORS —
Deflated balloons are placed through the endoscope and across the stricture. When inflated, they become sausage-shaped, stretch, and break the stricture.

ACHALASIA DILATORS —
Achalasia is a special situation which requires a larger, balloon-type dilator. The procedure is frequently done under x-ray control. In this procedure, the spastic muscle fibers in the lower esophagus are stretched and broken, which in turn allows easier passage of food and liquid into the stomach.

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