POEM (Peroral Endoscopic Myotomy) for Achalasia

POEM is a procedure that loosens the tight muscle ring at the lower end of the food pipe, so food and water can pass into the stomach again. It is done with an endoscope through the mouth, without any cuts on the skin.

The name explains the procedure. Peroral means through the mouth. Endoscopic means it uses an endoscope, a thin, flexible tube with a camera. Myotomy means cutting a muscle.

POEM is mainly used for achalasia. In achalasia, the muscle ring between the food pipe (oesophagus) and the stomach, called the lower oesophageal sphincter or LES, does not relax when you swallow. The food pipe also loses its normal squeezing movement. Food and liquid get held up in the chest. Read more about achalasia cardia: symptoms and causes.

Professor Haruhiro Inoue performed the first POEM in Japan in 2008 and published the first results in 2010.^1,6 The American College of Gastroenterology (ACG) guideline describes POEM, laparoscopic Heller myotomy and pneumatic balloon dilation as comparably effective treatments for type I and type II achalasia.²

Dr. Hitendra K Garg performs POEM at Indraprastha Apollo Hospitals, Sarita Vihar, New Delhi.

POEM is for people whose achalasia has been confirmed by tests. It can be the first treatment, or it can be used when balloon dilation or Heller surgery has stopped working. The right choice depends on your achalasia type, your age, your other health conditions and your own preference.

Manometry tests divide achalasia into three types (the Chicago Classification).⁸ The type matters because it changes which treatment is most likely to help.

Other conditions treated with modified POEM

• G-POEM (gastric POEM) for gastroparesis, a condition where the stomach empties too slowly. European guidelines advise it only for carefully selected patients, because long-term data are still limited.⁷
• Z-POEM for Zenker's diverticulum, a pouch that forms where the throat joins the food pipe and traps food. The muscle cut is made in the cricopharyngeal muscle (a cricopharyngeal myotomy).
• Spastic disorders such as jackhammer oesophagus and distal oesophageal spasm. European guidelines advise caution here, as the evidence is weaker than for achalasia.⁷

The main symptom of achalasia is difficulty swallowing both solids and liquids, often with regurgitation, chest pain and weight loss.² It usually starts slowly and gets worse over months or years.

• Food or water feels stuck in the chest
• Bringing back undigested food, often hours after eating or when lying down
• Chest pain or pressure, sometimes after meals
• Weight loss without trying
• Coughing or choking at night, from food coming back up
• Needing to drink water to push food down, or eating very slowly

Achalasia is sometimes mistaken for acidity or GERD, because both can cause chest discomfort and regurgitation. Acid-reducing medicines do not fix the tight muscle in achalasia. The ACG guideline advises testing for achalasia when suspected GERD does not respond to acid-suppressing treatment.² Read how acidity and GERD differ, and how to tell achalasia vs GERD apart.

See a gastroenterologist if swallowing has been difficult for more than a few weeks, if you are losing weight, or if food keeps coming back up. Difficulty swallowing always needs to be checked, because other conditions, including tumours, can cause it.

Three tests confirm achalasia and plan POEM: an upper GI endoscopy, high-resolution manometry and a timed barium swallow. Together they show the type of achalasia and rule out other causes of blocked swallowing.²

• Upper GI endoscopy: looks inside the food pipe and stomach. It checks for a tumour or narrowing that can look like achalasia (pseudoachalasia). Leftover food or saliva in the food pipe is a common clue. If a tumour is suspected, a CT scan or endoscopic ultrasound (EUS) may be added.
• High-resolution manometry (HRM): a thin tube through the nose measures the pressure of the food pipe and the LES as you swallow. This is the main test that confirms achalasia and its type.^2,8
• Timed barium swallow: X-ray pictures taken after drinking barium show how fast the food pipe empties. A widened food pipe with a narrow "bird's beak" at the bottom is typical.

The Eckardt score

Doctors measure how bad achalasia symptoms are with the Eckardt score.⁹ Four items are each scored 0 to 3, for a total of 0 to 12. A score of 3 or less after treatment is the usual definition of success in research studies.³

POEM is done under general anaesthesia, so you are asleep. It usually takes one to two hours. The procedure has five main steps.

1. Endoscope in: the endoscope is passed through the mouth into the food pipe. Carbon dioxide gas is used instead of air, because the body absorbs it quickly.
2. Small opening: a short cut, about 2 cm, is made in the inner lining of the food pipe, well above the stomach.
3. Tunnel: the endoscope makes a tunnel inside the wall of the food pipe, between the lining and the muscle, down to just below the stomach entry. In the first published series, the tunnel was about 12 cm long on average.¹
4. Muscle cut (myotomy): the inner circular muscle of the LES and the lower food pipe is cut. This is what loosens the blockage. In the first published series, the average muscle cut was about 8 cm long.¹
5. Closing: the opening in the lining is closed with small clips. The clips usually fall off on their own over the following weeks.

Because the muscle is reached from inside the food pipe, there are no stitches or scars on the skin.

Preparation for POEM focuses on emptying the food pipe and making anaesthesia safe. Your team will give you exact instructions, and these are the usual steps.

• Liquid diet: often clear liquids for one to two days before POEM, because food can stay in the food pipe for a long time in achalasia.
• Fasting: nothing to eat or drink for several hours before the procedure.
• Medicines: tell the team about every medicine you take, especially blood thinners, diabetes medicines and blood pressure tablets. Don't stop your prescribed medicines on your own. Your doctor will tell you which ones to pause, and when.
• Reports: bring your endoscopy, manometry and barium swallow reports, and any earlier treatment records.
• Support: plan for a family member to stay with you and take you home.

Most people stay in hospital for one to three days after POEM. They start on liquids, move to soft food over about two weeks, and then return to a normal diet. Many people notice easier swallowing within the first few days.

Most people return to desk work in about a week. Your follow-up plan will include a check for reflux, often with an endoscopy, because reflux after POEM can occur without heartburn.

Go back to the hospital straight away if you have fever, chest pain that gets worse, breathlessness, vomiting blood or black stools, or if you cannot swallow liquids.

Randomised trials show that POEM gives good symptom control for most people with achalasia at two years: about as well as Heller surgery, and better than balloon dilation.

• POEM vs Heller surgery: in a European trial of 221 patients (New England Journal of Medicine, 2019), 83.0% had good symptom control two years after POEM, compared with 81.7% after laparoscopic Heller myotomy. Serious adverse events occurred in 2.7% after POEM and 7.3% after Heller surgery.³
• POEM vs balloon dilation: in a trial of 133 newly diagnosed patients (JAMA, 2019), treatment was successful at two years in 92% after POEM and 54% after pneumatic dilation (two planned dilations, with 30 mm and 35 mm balloons).⁴
• Larger experience: in a series of 500 patients from the team that developed POEM, the procedure was completed in every patient, adverse events occurred in 3.2%, and symptom improvement lasted to three years.⁶

These are averages from research centres. Results vary from person to person. POEM relieves the blockage, but it does not repair the nerve damage behind achalasia. Lifelong follow-up is still needed, and some people need further treatment later.

The three main treatments for achalasia give similar early relief in many people. They differ in how they are done, in how often reflux follows, and in how often treatment needs to be repeated.

Botulinum toxin (Botox) injection into the LES is a fourth option. It is usually kept for people who are not fit for the other treatments, because its effect wears off over months.²

For more detail on which option suits whom, read Heller myotomy vs POEM vs balloon dilation.

POEM is a safe procedure for most people, but like any procedure it has risks. In a large randomised trial, serious adverse events occurred in 2.7% of patients after POEM.³ Reflux is the most common long-term side effect.

• Reflux (GERD): acid comes up from the stomach because the LES is looser. See the next section.
• Gas in the chest or abdomen: carbon dioxide can collect outside the food pipe during the procedure. It is usually managed during POEM and settles quickly.
• Bleeding: usually small and controlled during the procedure. Rarely, bleeding happens later.
• Injury to the lining or a leak: rare, and usually treated with clips or endoscopic treatment.
• Chest pain or a sore throat for a few days after POEM.
• Chest infection (aspiration pneumonia), especially if food was left in the food pipe.
• Risks of general anaesthesia, which your anaesthetist will discuss.
• Symptoms not improving or coming back, which may need a second treatment.

Reflux is more common after POEM than after Heller surgery with a wrap or balloon dilation, because POEM does not add an anti-reflux wrap.² In a review of 17 POEM studies (1,542 patients), 19% had reflux symptoms, 39% had raised acid on pH testing and 29% had reflux inflammation on endoscopy.⁵

After Heller surgery with a wrap, the same review found 8.8%, 16.8% and 7.6%.⁵

Reflux after POEM is usually controlled with acid-reducing medicines such as proton pump inhibitors. It can be silent, without heartburn, so a follow-up endoscopy and sometimes a pH test are advised.⁵ For symptoms, tests, medicines and long-term follow-up, read the full guide to reflux after POEM. Learn more about GERD symptoms and treatment.

The cost of POEM depends on the hospital, the room category and how long you stay. A written estimate is given once the tests are done and the plan is clear. These are the main factors:

• Tests before POEM, if not already done (endoscopy, manometry, barium swallow)
• Room category and number of days in hospital
• Anaesthesia, and the endoscopic equipment and clips used
• Medicines, and any extra care needed if there is a complication
• Follow-up visits and endoscopy

If you have health insurance, ask your insurer or the hospital's insurance (TPA) desk about cover and pre-authorisation before the procedure.