What to Expect During an Esophageal Manometry Test

Human food pipe, illustration
SCIEPRO/SCIENCE PHOTO LIBRARY / Getty Images

Esophageal manometry is a commonly used test to help determine esophageal motor dysfunction. This test helps your physician evaluate pressures within your esophagus, peristalsis (involuntary contraction and relaxation in your esophagus), and the movement of food through your esophagus. The most common reasons your physician may recommend an esophageal manometry test include:

  • difficulty swallowing (dysphagia)
  • chest pain that is not cardiac (heart) related
  • acid reflux
  • before anti-reflux surgery

You may also likely be recommended for this test to help assess for the following disorders:

Your Esophagus

The esophagus is a long muscular tube that extends from your throat to your stomach and is sometimes referred to as your "gullet." There is a sphincter, or a muscular ring that opens and closes, at the top and the bottom of your esophagus. These are respectively referred to as the upper esophageal sphincter and the lower esophageal sphincter. These sphincters open and close naturally while swallowing food or drink.

Your upper esophageal sphincter (UES) serves 2 main purposes:

  1. closes during inspiration to avoid filling your stomach up with air
  1. closes to prevent acid-reflux from entering your lungs

Your lower esophageal sphincter's (LES) main purpose is to prevent stomach acid from entering into your esophagus. To prevent this, your lower esophageal sphincter typically remains closed until swallowing food at which point it briefly relaxes to allow the passage of food from your esophagus into your stomach.

There is also a brief relaxation of the lower esophageal sphincter when you belch.

Preparing for an Esophageal Manometry Test

Preparation for an esophageal manometry test includes safety measures to prevent aspiration (inhalation of stomach contents) and optimization of test results. In order to ensure that your stomach is empty, your doctor will likely recommend that you fast for at least six hours before your procedure. If you eat before this time, your doctor may cancel or delay your testing.

Many medications can affect your esophagus and therefore your doctor may ask you to temporarily stop taking certain medications. Some medications may not be able to be stopped and therefore you should discuss your medications with your physician before the procedure. Any medications that are taken only "as needed" should not be taken prior to the procedure.

Common types of medications that may affect the results of an esophageal manometry test include:

  • nitrates - nitroglycerin, isosorbide, Viagra, Cialis
  • calcium-channel blockers - Norvasc, Cardizem
  • anticholinergics - Cogentin, Spiriva, Atrovent, Ditropan
  • promotility agents - Reglan, Zelnorm
  • sedatives - Versed, Ativan, Fentanyl

It is important to discuss medications with your physician before stopping anything that you take regularly.

What to Expect During an Esophageal Manometry Test

Most of the time sedation will not be used while inserting the esophageal motility catheter. While mild sedatives like low doses of Versed may be used to enhance comfort, sedatives can affect esophageal testing, so they are avoided when possible.

In order to enhance your comfort, you will likely be given the choice of which nostril you would like the doctor to insert the catheter into. The nasal route is preferred as it tends to cause less gagging and is less bothersome once in place as opposed to going through your mouth. Your doctor is highly trained in performing this procedure, so trust them and try to relax.

If you feel severe discomfort, communicate that to them.

Before starting, you should remove glasses and anything in your mouth that can be easily removed. You should remove these items because gagging is normal during the insertion of the catheter.

Here's what will happen throughout the procedure:

  1. Before inserting the esophageal motility catheter, the tip of the catheter will be lubricated with a topical anesthetic. If the insertion is too uncomfortable, they can also have you sniff a small amount or lubricate your nostril with a swab coated with a topical anesthetic.

    The largest point of resistance occurs when the catheter reaches the back of your nares and enters into your throat because of the bend that it has to make. During this part of the procedure, you will be asked to tilt your head down, placing your chin towards your chest to help make the turn with the catheter.
  2. In order to help move the catheter past your upper esophageal sphincter, you will be asked to sip some water through a straw. If you begin to cough repeatedly and have difficulty speaking, it may mean that the tube went into your trachea instead of your esophagus. This occasionally happens and the clinician performing the procedure will withdraw the catheter a little and try again after you have had a chance to relax and catch your breath.
  3. Once the catheter is past your upper esophageal sphincter, the catheter can be advanced quickly down your esophagus. The esophageal motility catheter will then be taped to your nose once the proper depth has been attained. You will then be asked to lie down while the catheter is properly calibrated for testing. During calibration, you should refrain from swallowing to allow for optimal calibration.
  4. Testing begins with the two last sensors being in the stomach. You will be asked to take a deep breath to help confirm proper placement within your stomach. Once established, the esophageal motility catheter pressure measurement is set to zero. While the actual pressure is not really zero, the stomach is marked as zero to act as a baseline for measuring the pressure at your lower esophageal sphincter.
  5. After stomach baseline measurements are established, the esophageal motility catheter is withdrawn to the lower esophageal sphincter. Once properly positioned, you will be given several sips of room temperature water (about 5 mL or a little more than one teaspoon). They will be measuring the pressure that exists at rest (sphincter in a closed position) and when the sphincter relaxes during the swallowing of the water.

    When the sphincter relaxes, it should normally come close to the pressure level of the stomach that was set to zero earlier in the test. During the test, you will be asked to breathe quietly at a normal depth to allow for proper measurement.
  6. With the last sensors in the high-pressure zone of your lower esophageal sphincter, they will also take measurements during swallowing of water of how your esophagus reacts to swallowing. Your esophagus should show increased pressure starting at the highest part of your esophagus and they should observe pressure increase down the esophageal motility catheter as the water travels down toward your stomach.

    This wave of pressure increase is because of peristalsis, or the involuntary contraction of the esophageal muscle to move contents toward your stomach. As in the previous step, when the water is at the level of your upper esophageal sphincter, the pressure level should approach zero.
  7. When testing your upper esophageal sphincter, you will be asked to sit up. The esophageal motility catheter will be moved slowly and positioned where they can identify the high-pressure zone of your upper esophageal sphincter. The pressure at the sphincter will be compared to an established baseline pressure in the main part of your esophagus. Once pressure is at rest, or in a closed position, the pressure during swallowing will be measured. At this point, with proper positioning, the test can also detect coordination between your throat and your upper esophageal sphincter.

Possible Complications

Know that complications related to esophageal manometry testing are rare. However, any of the following complications may occur:

  • irregular heartbeats
  • aspiration (acid or stomach contents flowing up the esophagus and into your lungs)
  • perforation (tearing) of your esophagus
  • tube placed into lung instead of in the esophagus - easily corrected during insertion

Many of these are avoidable by following instructions provided by your physician before the procedure.

Alternatives to Esophageal Manometry Testing

Esophageal manometry is the best method for assessing any dysfunction with esophageal motility. However, a barium swallow study may be used to evaluate the function of your esophageal sphincter function.

There is also a newer more robust version of esophageal manometry called high-resolution manometry. Instead of using eight sensors in the esophageal motility catheter, the high-resolution catheter uses 36 sensors. The technique used to measure is the same. However, once the catheter is properly placed, no withdrawal of the catheter is required. It also allows for a 3-dimensional pressure map called esophageal pressure topography that may be useful in determining some disorders with asymmetrical sphincter dysfunction.

A Word From Verywell

If you're feeling nervous or overwhelmed when your doctor recommends an esophageal manometry test, know that the procedure is simple and rarely causes complications, especially when you follow instructions. Knowing what to expect can help relieve some fear, and if you're still nervous about a specific step in the procedure, let your doctor know. He or she may have helpful recommendations.

Sources:

High resolution manometry. UpToDate website. https://www.uptodate.com (Subscription Required). Updated Jul 10, 2017.

Overview of gastrointestinal motility testing. UpToDate website. https://www.uptodate.com (Subscription Required). Updated Sep 12, 2016.

Richter, JE & Castell, DO. (2012). The Esophagus. 5th ed. Wiley-Blackwell. pp 163-181.

Understanding Esophageal Manometry. American Society for Gastrointestinal Endoscopy website. https://www.asge.org/home/for-patients/patient-information/understanding-esophageal-manometry.