What Happens during Normal Swallowing?

When we chew food, our mouth and tongue forms this into a lump shape, called a bolus. When we swallow, the bolus passes through the throat (pharynx) and travels down a tube called the esophagus, into the stomach (sometimes you can feel this when you swallow something too big or hard). The esophagus actually moves to help pass the bolus down. These movements are muscle contractions that coordinate like waves. They are known as esophageal or peristaltic contractions. Also, so that the food travels in the right direction, at the top and bottom of the esophagus there are valve-like parts, called sphincters. Since they are at the top and bottom, they are called upper and lower sphincters. When food passes the throat, it sets off nerve messages that open or close the sphincter “valves” for the food to pass down to the stomach.

What Are Esophageal Motility Disorders?

Esophageal motility disorders, or EMDs for short, are problems with the movement of food through the esophagus. Esophageal refers to the esophagus food tube and motility refers to movement.

EMDs fall into two categories:

1. Primary EMDs are caused by problems with the nerve messaging that controls the esophagus movements or esophagus sphincters. This is the type that the authors focused on.
2. Secondary EMDs are caused by, for example, cancer blocking the esophagus, and require other specialist diagnosis and treatment.

What Are the Symptoms of an EMD?

There are no specific symptoms that definitely say a person has EMD unless they also have some tests. Doctors need to know about a person’s other health concerns and recognize warning signs. These can be:

• difficulty swallowing,
• pain in the chest area,
• past stomach or bowel surgery,
• the use of some medications.

If you have chest pain, you should seek medical help in case it has a serious cause. Since there are many body parts in the chest area, it is difficult to pinpoint pain as it tends to be inexact. Chest pain can be caused by mild problems such as heartburn or a pulled muscle through to serious problems such as a heart attack.

What Screening Tests Are Used When an EMD Is Suspected?

First, screening tests should be carried out. These include testing for heart problems (that might be causing the chest pain) and also for problems such as acid reflux (heartburn). Screening tests are easily available in most countries, and can also help diagnose a different cause of a person’s symptoms.

Endoscopy is a screening test where a tiny camera is passed down the esophagus, to view inside and see what is going on. Small samples can also be taken, and then examined in a laboratory. The patient is given medications so that they are drowsy and comfortable throughout.

Barium swallow is a test where the patient swallows a thick drink with barium in it. Barium shows up on x-rays. A moving (film) x-ray or a still image x-ray will be taken, so that the esophagus and other body parts, and the food movement are viewed. However, a barium swallow cannot exactly show the movement problems that happen with EMD, so the test can only help by showing up other causes of the symptoms. The authors describe some possible variations to barium swallow that could help with better EMD diagnosis. These include swallowing a rice ball with barium (rather than a drink), taking timed x-rays to compare food movements, and researching results with different amounts and thickness of the barium drink.

What Specific Tests Are Used to Diagnose EMD?

High-resolution manometry (HRM) is a specific test for EMD where a thin tube (catheter) is passed down the esophagus through the nose and throat and the patient swallows a drink or something thick. The patient stays alert so that they can swallow, but receives some numbing medicine in the throat so that this is comfortable. This tube contains many pressure sensors, which measure the esophagus muscle contractions (strength, speed, location and so on) during swallowing. The measurements can be made during both lying down and sitting up, which gives even more information to help diagnosis and plan treatment.

How Is EMD Treated?

The tests will show what type of movement problem there is, such as the esophagus muscles being too strong or weak, or their coordination badly timed. Treatment can then be planned. For example, medicines can be given to help the esophagus muscle to contract better or move more smoothly. Or, a small operation can be done to either increase the size of the esophagus (pneumatic dilation (PD)) or create a new tube entrance in the stomach that “bypasses” muscles that contract too much (per-oral endoscopic myotomy (POEM) and laparoscopic Heller myotomy (LHM)).

Is Treatment Successful?

The authors describe some statistics for treatment success. For most types of EMD the surgery treatments were more successful than the medicine treatments, with roughly 3 out of 4 people experiencing improvement. However, for some types of EMD, the best treatment was to simply change the type of food or eating position.

Take-Home Message

The authors state that, since there is still a lot to learn about EMDs, diagnosis should be thorough and confident before any operations are carried out. Also, it is very important that any chest pain is properly checked to ensure it is not a heart problem.