Per-oral endoscopic myotomy (POEM)

What is POEM?

POEM stands for per-oral endoscopic myotomy. This resource will provide some information about the procedure and what to expect.

POEM is a treatment for a condition called achalasia, pronounced ‘a-ka-lay-si-a’.

Achalasia affects the muscles of the oesophagus (food pipe). It often causes:

• difficulty swallowing
• food sticking in the food pipe
• chest pain
• throwing up
• weight loss

What is achalasia?

Achalasia happens when the muscles in the food pipe contract in an uncoordinated way.

It makes it difficult for swallowed food to move down the food pipe, and into the stomach.

The muscles at the end of the food pipe (called the lower oesophageal sphincter), does not relax, which stops the food from going into the stomach.

This means that the food pipe is blocked, and food can build up.

Why do I have achalasia?

Achalasia is caused due to damage to the nerve in the oesophagus (food pipe) where the sphincter (the muscle at the end of the pipe where it opens to the stomach). Either it does not contract or relax as needed, or there is a mechanical cause of progressive obstruction.

The exact cause of this condition is not known, but the following factors may play a role:

• autoimmunity
• family history
• parasitic infection is known as Chagas disease (which is uncommon in the UK)
• cancer of the oesophagus (which is rare in children)

Unfortunately, there is no cure. However, there are treatment options available to relieve symptoms.

What are the complications of achalasia?

How does POEM work?

During the procedure, we will use an endoscopy, which is a long flexible camera, to look down the food pipe. This is called an upper gastrointestinal endoscopy.

There are 3 layers of muscle in the food pipe. Using instruments through the endoscope, we make a small cut in the wall of the food pipe, between the layers of muscle. We then gently create a tunnel between these layers with some gas.

This allows us to insert the endoscope into the tunnel, down to the end of the food pipe, where the muscles to the stomach are (the lower oesophageal sphincter).

Here, we cut the inner muscular layer, which makes the sphincter relax. This will allow food from the food pipe into the stomach.

We will then take out the endoscope and use clips to repair the first cut that created the tunnel.

Petrov, Roman & Fajardo at al. (2021). Peroral endoscopic myotomy: Techniques and outcomes. Shanghai Chest. 2021:5.14-14

Why POEM?

This procedure is safe, and minimally invasive, which means there is no major surgery or scars.

It also lets us cut the muscles from much further up the food pipe if needed, and we can be more selective.

POEM can give the best results possible, to relieve symptoms of achalasia.

What are the alternatives?

We understand that you may not want to have a procedure, or want to think about other options.

Medication

Calcium channel blockers such as nifedipine can be used to treat achalasia by relaxing the lower oesophageal sphincter. However, we know that this does not adequately resolve symptoms and can cause side effects.

Botox

Botox can be injected in to the lower oesphageal sphincter and make it relax. However, Botox is temporary and wears off, so the procedure would have to be repeated regularly.

Pneumatic balloon dilatation

Pneumatic balloon dilation procedure uses a balloon to physically stretch the muscles of the lower oesophageal sphincter, which makes them relax. However, this needs to be repeated and is associated with around a 2 to 8 percent risk of the food pipe tearing, and a risk of bleeding.

Heller’s myotomy and laparoscopic fundoplication

This is ‘keyhole’ surgery, where the lower oesophageal sphincter is cut and then part of the stomach is wrapped around the spincter, which reduces reflux. The benefit of this operation is that it can reduce post-operative reflux.

What are the side effects or complications of POEM?

POEM is a safe procedure. Like most procedures, some people experience mild pain afterwards

Acid reflux can occur due to the relaxed sphincter. This can be treated with anti-reflux medication. The risk of reflux is somewhere between 20 and 40 percent.

Mediastinitis is an infection in the chest wall cavity. It can come about a few days after the procedure, and can cause chest pain and a high temperature. This is treated in hospital with IV antibiotics.

When we create the tunnel for the endoscope, we use a bit of gas to inflate the tunnel. Sometimes this gas can escape into other areas such as the skin, causing a ‘bubble pop’ sensation. This is called surgical emphysema.

If the clips we use to repair the entry point of the tunnel fall, there may be a risk of food leaking into the tunnel. This could cause pain and infection.

Bleeding can happen immediately after the procedure or up to 2 weeks after. Usually this is small and will stop on its own. If there is further bleeding, you should contact the team for assessment.

There is a risk of causing a hole or rip in the food pipe. This is a rare complication, which can be managed during the procedure with clips. Sometimes, it becomes apparent after being discharge. Rarely, this may need further intervention, including surgery.

There is also a risk of ‘mediastinitis’ which is an inflammation of the tissues in the mid-chest area. The risk of this happening is less than 1 percent.

What happens before POEM?

Your child will be admitted to theatre admission unit (TAU) which is at the top of the green lifts in Sheffield Children’s Hospital.

You will meet your surgical team and anaesthetic team. The nursing staff will admit you to the ward and check your observations such as heart rate and blood pressure. If you have any worries, concerns or questions, we will be there to listen.

How should we prepare?

All POEM procedures must be done on an empty stomach.

5 days before the procedure

Your child must stop eating all solid foods and have a liquid-only diet.

A liquid diet means:

• normal clear drinks

• food that is the consistency of nutritional supplement drinks

• blended soups

It is very important that you follow this, otherwise it might affect your child’s operation.

The day of the procedure

Your child cannot drink anything for 4 hours before their procedure.

Eating and drinking before the procedure makes it dangerous with general anaesthetic, and the procedure will most likely be cancelled.

What should we bring on the day?

Please bring pyjamas, toiletries, phone chargers. Your child will be staying in overnight on one of the medical wards.

Will my child be asleep for the procedure?

Yes, this procedure is done under general anaesthetic.

You will see your child in the anaesthetic room in theatres. In the anaesthetic room, a small cannula (plastic straw) will be inserted into their hand, and an oxygen mask will be placed over their face.

What happens after the procedure?

The procedure takes about an hour.

Your child will be woken up in recovery part of theatres and where you can come see them.

Most children have mild discomfort or chest pain after the procedure which is treated with pain relief medication.

After a POEM procedure, your child will usually stay in hospital for 1 night. Although the length of their hsopital stay will depend on how well they are recovering.

The day after the procedure, your child may be asked to have a swallow test X-ray. This is to make sure there are no leaks from the food pipe after the procedure.

Your child will be discharged home the day after their procedure, if they are well enough.

Your child will be prescribed a 3 month course of an acid suppression medication called PPI (lansoprazole or omeprazole).

What can my child eat and drink after a POEM?

The diet after a POEM procedure is important to let the food pipe to heal. Not sticking to the diet can result in the cut opening up and causing an infection.

First 24 hours

For the first 24 hours, your child will be on IV fluids and only small sips of fluid will be allowed.

Day 1 to day 7

If you have been asked to wait for a swallow test, please remain on sips of water until the results have been reviewed.

After this, your child can start on a liquid diet. A liquid diet means only clear liquids, food that is the consistency of nutritional supplement drinks and blended soups. This is the same same as before the procedure.

Day 8 to day 14

After the first week, your child can have a pureed diet.

After 2 weeks

Unless they are still struggling to swallow, your child can go back to a normal diet after 2 weeks.

What happens next?

Afterwards, an appointment will be made for a follow up with your lead consultant to assess your child’s symptoms after the procedure.

What should I do if my child becomes unwell?

Bleeding or perforations (rips or tears) can occasionally happen several days after the procedure.

Your should go to your nearest Emergency Department if your child experiences:

• severe pain in their tummy

• feeling sick or being sick

• being sick with blood

• having bloody or black poos