Peroral endoscopic myotomy, or POEM for short, is a minimally invasive, endoscopic procedure used to treat achalasia, a disorder of the esophagus that makes it difficult to swallow food and beverages. POEM is sometimes used to treat other swallowing disorders as well.

When you swallow food, it moves from your mouth into the esophagus, where muscles contract to push food down toward the stomach. At the end of the esophagus, where it meets the stomach, the food reaches the lower esophageal sphincter (LES), a ring of muscle, which relaxes—or opens—to allow food to pass into the stomach.

When people with achalasia swallow food, however, the esophagus muscles do not contract correctly, impairing the movement of food down toward the stomach. At the same time, the LES fails to relax properly, which means food cannot pass into the stomach. Instead, it remains in the esophagus—and only slowly works its way down into the stomach. This can result in chest pain, regurgitation of undigested food, and significant weight loss. 

There are several treatments for achalasia, but POEM, a recently developed procedure, is increasingly being used. POEM relieves symptoms in around 90% of achalasia cases, and serious complications are rare. What’s more, it’s less invasive than other surgical treatments—even other minimally invasive surgical procedures—and in the majority of cases, recovery is quick. 

“POEM is an exciting technique used to perform a myotomy of the LES for the treatment of achalasia,” says Yale Medicine gastroenterologist and endoscopy specialist Harry Aslanian, MD. “POEM is remarkably effective and safe, achieving similar results to a surgical approach, but without requiring any skin incisions.”  

Several therapies are available for treating achalasia, all of which are aimed at helping the LES to relax or open, so that food and liquid can more easily move into the stomach from the esophagus.

One treatment option, called pneumatic dilation, involves the inflation of a balloon inside the esophagus to stretch out the LES. Another option involves Botox injections into the LES to help the LES muscle relax. Medications like nitrates or calcium channel blockers, both of which allow the LES to relax, are sometimes used as well. These treatments can help, but their effect is usually temporary and often require repeated treatments.

One commonly used therapy that offers long-lasting results is a surgical procedure called a Heller myotomy. While this sometimes requires open surgery, this procedure can be done using minimally invasive techniques. This means the surgeon makes a few small incisions in the patient’s abdomen through which he or she inserts tools to access the LES. The surgeon makes some cuts in the LES and nearby muscles in the esophagus and stomach. After the procedure, food and liquid should more readily pass through the LES into the stomach.

POEM is similar to a Heller myotomy in that it involves cutting the LES and nearby muscles, but it is less invasive and does not require any skin incisions.

During POEM, with the patient under general anesthesia, a doctor inserts an endoscope—a thin, flexible tube equipped with a camera and surgical instruments—into the patient’s mouth and guides it down into the esophagus.

Once the endoscope is in place, the doctor uses instruments passed through the scope to make a small cut in the mucosa, the membrane that lines the esophagus. An electric scalpel at the tip of a small flexible catheter, also called an electrocautery knife, uses electric current to cut through tissue and also seal blood vessels. The doctor inserts the endoscope into this small incision, and can pass the endoscope via a temporary tunnel through a middle layer of esophageal tissue called the submucosa. He or she guides the endoscope through this tunnel until it reaches the lower esophagus. Once there, the doctor makes incisions in the LES, as well as in the muscle in the lower esophagus and upper stomach, so that it relaxes and allows food to pass into the stomach.

The doctor may check the adequacy of the myotomy by using a special pressure balloon (called an Endoflip) during the procedure. The doctor then withdraws the endoscope, inspecting the tunnel along the way to check for signs of tears and bleeding, then closes the initial incision with small clips or sutures passed through the scope.

A day or two before the procedure, you will be put on a liquid diet. If you are on blood thinners, you must stop using them prior to the procedure. Other medications may need to be adjusted as well. The day of the procedure, you will typically be given intravenous antibiotics to prevent infections.

You typically stay in the hospital overnight after the procedure and may be given medication for pain control. An esophagram—an X-ray of the esophagus—may be performed to check that the esophagus is emptying. In most cases, you can go home the next day.

To give the esophagus time to heal after POEM, you should follow a liquid diet for a week after the procedure, then progress to a soft food diet for another week before finally introducing other foods. You will also take antibiotics for a few days to prevent infection and be given a medication called a proton pump inhibitor (PPI) to reduce potential symptoms of acid reflux.  

Periodic follow-up appointments that involve X-ray imaging studies and an examination of the esophagus using an endoscope are necessary to make sure that the esophagus and LES are working well.

POEM can be used to treat esophageal motility disorders (EMDs) that make swallowing difficult, including:

• Achalasia (for which the procedure was developed)
• Distal esophageal spasm (DES)
• Jackhammer esophagus, also known as hypercontractible esophagus
• Nutcracker esophagus, also known as hypertensive esophageal peristalsis
• Esophagogastric (EG) junction outflow obstruction

POEM can be used in patients who have previously received other treatments for achalasia, including balloon dilation, Botox injections, or a Heller myotomy. It is safe for patients of all ages, including children and older adults.

But POEM is not recommended for use in certain patients. For instance, people who have severe liver disease, blood clotting disorders, severe bullous lung disease, or severe esophagitis (an inflammatory disorder of the esophagus) are not good candidates for the procedure. 

Similarly, POEM is not recommended for those who have had previous medical treatments that may have damaged tissues of the esophagus, such as radiation therapy or ablation procedures.

While POEM is a safe procedure, it does come with certain risks. Fortunately, complications from POEM are rare but may include tears in the tissue lining the esophagus (the mucosa), bleeding, collapsed lung, and pneumomediastinum (air in the mediastinum, the space between the lungs).

While the Heller myotomy procedure often includes fundoplication, a procedure to reduce acid reflux into the esophagus, this is not usually part of the POEM procedure. This means that after POEM, stomach acid may more easily flow back up into the esophagus. Because of this, people who undergo POEM may develop gastrointestinal reflux disease (GERD); however, this is typically managed with the use of acid-blocking medications, such as proton pump inhibitors, taken once a day.