Retrograde Cricopharyngeus Dysfunction (R-CPD)

Inability to belch or “burp” (Also known as Retrograde Cricopharyngeus Dysfunction, or R-CPD for short) occurs when the upper esophageal sphincter (cricopharyngeus muscle) loses its ability to relax in order to release the “bubble” of air. The sphincter is a muscular valve that encircles the upper end of the esophagus just below the lower end of the throat passage. If looking from the front at a person’s neck, it is just below the “Adam’s / Eve’s apple” and more specifically, directly behind the cricoid cartilage.

If you care to see this on a model, look at the photo below. That sphincter muscle relaxes for about a second every time we swallow saliva, food, or drink. All of the rest of the time it is contracted. Whenever a person belches, the same sphincter needs to let go for a split second in order for the excess air to escape upwards. In other words, just as it is necessary that the sphincter “let go” to admit food and drink downwards in the normal act swallowing, it is also necessary that the sphincter be able to “let go” to release air upwards for belching.

People who cannot release air upwards are miserable. They can feel the “bubble” sitting at the mid to low neck with nowhere to go. Or they experience gurgling when air comes up the esophagus and is blocked by a non-relaxing sphincter. It is as though the muscle of the esophagus continually churns and squeezes without success. The person so wants and needs to burp, but can’t. Sometimes this can even be painful. Such people often experience abdominal bloating as the air must make its way through the intestines before finally being released as flatus.

For people who experience this problem to the point of discomfort and reduced quality of life, here is one approach: First, a videofluoroscopic swallow study, perhaps with effervescent granules. This establishes that the sphincter works normally in a forward (antegrade) swallowing direction, but not in a reverse (retrograde) burping or regurgitating fashion. Along with the symptoms described above, this establishes the diagnosis of retrograde-only cricopharyngeus dysfunction (non-relaxation).

Second, a treatment trial involving placement of Botox into the malfunctioning sphincter muscle. The desired effect of Botox in muscle is to weaken it for at least several months. The person thus has many weeks to verify that the problem is solved or at least minimized. The Botox injection could potentially be done in an office setting, but we recommend the first time (at least) placing it during a very brief general anesthetic in an outpatient operating room. That’s because the first time, it is important to answer the question definitively, that is, that the sphincter’s inability to relax when presented with a bubble of air from below, is the problem.

For a few months at least, patients should experience dramatic relief of their symptoms. And, early experience suggests that It may be that this single Botox injection allows the system to “reset” and the person may never lose his or her ability to belch. Of course, if the problem returns, the individual could elect to pursue additional Botox treatments, or in a truly severe case, might even elect to undergo endoscopic laser cricopharyngeus myotomy.


Photos of the cricopharyngeus muscle:

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Location of the cricopharyngeus muscle

Cricopharyngeus Muscle (1 of 3)

The highlighted oval represents the location of the cricopharyngeus muscle.
Retrograde Cricopharyngeus Dysfunction (R-CPD)

Cricopharyngeus Muscle (2 of 3)

The cricopharyngeus muscles in the open position.
Contracted Cricopharyngeus Muscle

Contracted Cricopharyngeus Muscle (3 of 3)

The cricopharyngeus muscle in the contracted position.

R-CPD and esophageal dilation: Series of 3 photos

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between posterior pharyngeal wall and arytenoid eminences

(1 of 3)

Here, in the panoramic view of the "bottom of the throat," between posterior pharyngeal wall (marked PPW) and arytenoid eminences (A). The airway is indicated by the short arrow, and the dotted line shows the waiting "entrance" to the upper esophagus just above the CPM. The "entrance" opens for a second to permit passage of food or liquid through the sphincter and into the upper esophagus. The * is for reference with photo 2.
entrance to the esophagus

(2 of 3)

At the entrance to the esophagus, at closer range. Notice that the mucosa is redundant, a common but not universal finding in R-CPD.
upper esophagus

(3 of 3)

Now the view is within the upper esophagus. It almost appears that the lumen is dilated, especially in a lateral direction (arrows). Purely speculatively, one wonders if constant forcing of air upwards again a barrier ( the non-relaxing cricopharynxgeus muscle, aka upper esophageal sphincter), dilates the esophagus over time. Certainly, many with R-CPD experience not only gurgling, but also chest pressure and even pain that may be from "stretching" of the esophagus.

Esophageal Findings: Series of 3 photos

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A view of the mid-esophagus

Esophageal Findings (1 of 3)

A view of the mid-esophagus in a young person (early 30’s). The esophagus is kept open by the patient’s un-burped air. Note the “aortic shelf” at A, delineated by dotted lines.
A bony spur in the spine

Esophageal Findings (2 of 3)

A moment later, additional air is pushed upwards from the stomach to dilate the mid-esophagus even more. A bony “spur” in the spine is thrown into high relief by the stretched esophagus.
dilation of the upper esophagus

Esophageal Findings (3 of 3)

A view of the upper esophagus (from just below the cricopharyngeus muscle sphincter) shows what appears to be remarkable lateral dilation (arrows) caused over time by the patient’s unburpable air. Dilation can only occur laterally due to confinement of the esophagus by trachea (anteriorly) and spine (posteriorly), as marked.

Abdominal Distention of R-CPD: Series of 3 photos

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x-ray of Gastric Air Bubble

Gastric Air Bubble (1 of 3)

This abdominal xray of an individual with R-CPD shows a remarkably large gastric air bubble (dotted line), and also excessive air in transverse (T) and descending (D) colon. All of this extra air can cause abdominal distention that increases as the day progresses.

Bloated Abdomen (2 of 3)

Flatulence in the evening and even into the night returns the abdomen to normal, but the cycle repeats the next day. To ask patients their degree of abdominal distention, we use pregnancy as an analogy in both men and women. Not everyone describes this problem. Most, however, say that late in the day they appear to be “at least 3 months pregnant.” Some say “6 months” or even “full term.” In a different patient with untreated R-CPD, here is what her abdomen looked like late in every day. Her abdomen bulges due to all of the air in her GI tract, just as shown in Photo 1.

Non-bloated Abdomen (3 of 3)

The same patient, a few weeks after Botox injection. She is now able to burp. Bloating and flatulence are remarkably diminished, and her abdomen no longer balloons towards the end of every day.

What the Esophagus Can Look Like “Below A Burp”: Series of 3 photos

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Mid-esophagus of a person with R-CPD

Baseline (1 of 3)

Mid-esophagus of a person with R-CPD who is now burping well after Botox injection into the cricopharyngeus muscle many months earlier. The esophagus remains somewhat open likely due to esophageal stretching from the years of being unable to burp and also a “coming burp.”
esophagus dilates abruptly

Pre-burp (2 of 3)

A split-second before a successful burp the esophagus dilates abruptly from baseline (photo 1) as the excess air briefly enlarges the esophagus. An audible burp occurs at this point.
burp in the esophagus

Post-burp (3 of 3)

The burp having just happened, the esophagus collapses to partially closed as the air that was “inflating it” has been released.