Per Oral Endoscopic Myotomy (POEM)
is a safe and novel endoscopic treatment modality available for achalasia.
Since its birth in 2008, more than 3000 procedures have been done in over 50 centers worldwide; POEM is regarded as a first line management for all types of achalasia.
Achalasia is a rare condition affecting the esophagus (the food pipe). There is a muscular sphincter that acts as a gateway for food entering the stomach from the esophagus. The timely opening of this ‘lower esophagus sphincter’ (LES) gets affected in patients suffering achalasia. The LES fails to open, and peristalsis (the peristaltic wave is what drives the food down through our digestive tracts) is affected. Achalasia is thought to arise out of autoimmune causes, though no definitive cause has been proven till date. People with achalasia present with clinical features like difficulty with swallowing foods, regurgitation of swallowed food, chest pain, weight loss and heart burn.
Multiple treatment strategies have been tried to control achalasia. It started with pharmacologic approaches using drugs belonging to classes known as nitrates and calcium channel blockers; botulinum injection
was also tried. None of these yielded long-term benefits. A surgical technique known as Laparoscopic Heller Myotomy (LHM) was introduced in 1991. LHM had been the only effective solution available for achalasia till the entry of POEM in 2008. LHM produces excellent symptom resolution and is still considered as a gold standard therapy, but it involves an invasive surgery with risks. POEM is the safest and equally efficient alternative to LHM.How does POEM treat achalasia? How is it performed?
The esophagus has two layers of muscles, inner circular (or circumferential) and outer longitudinal muscles. In POEM, an instrument known as the endoscope is passed through the mouth. Under direct visualization, a special knife is used to make cuts in the inner circular muscles of the lower esophagus (cuts also extend to the upper parts of the stomach). This releases the tone of the LES (previously described) and thus facilitates normal passage of food. The upper part of the incision is then closed using endoscopic clips. Is POEM painful?
POEM is performed under general anesthesia, hence there won’t be any pain during the procedure.How long is the procedure?
Depending upon the complexity that varies with patients, POEM can take between 1 and 4 hours. Multiple factors including the experience of the operator will influence the time taken to perform POEM. Patients who have previously underwent other treatments for achalasia may require longer times.Will previous modalities of treatment for achalasia make me unfit for POEM?
No. It may be technically a little more difficult for the endoscopist to perform POEM on you; the previous procedure might have distorted the anatomy. Apart from this and the probable longer duration required, there are no issues.What are the indications for POEM?
POEM can be done in all cases of achalasia, other motility disorders of the esophagus like ‘diffuse esophageal spasm’ and in those who had previously underwent multiple endoscopic treatments. Elderly people and children are also eligible candidates for POEM.Are there contraindications for POEM?
People who have had radiation therapy to the esophagus and those who have had treatments that affect the protective mucosal cover of the esophagus cannot undergo POEM. People with severe disease of the lung or the liver (cirrhosis) and those with disorders affecting blood coagulation are poor candidates for POEM.How do I prepare for POEM?
You will be advised to take clear liquid diet or a low residue diet for two days prior to POEM. Some doctors also recommend sips of carbonated drinks during this period. You may be asked to abstain from oral feeds for about 12 hours prior to POEM. These advices may vary with the center where POEM is performed. What tests will I go through prior to POEM?
Apart from the routine screening blood investigations you may be subjected to esophagography, endoscopy and esophageal motility study so as to confirm the diagnosis of achalasia. Will there be any incisions on my body? Will POEM leave behind any scars on my body?
No external incisions are made during POEM and hence it does not leave behind scars. POEM is entirely done endoscopically. Incision is made in the inner lining of the esophagus under direct vision using an endoscope. Who performs POEM? Which doctor should I consult? Is it done in an operation theater?
POEM is usually performed by an expert Medical Gastroenterologist. It can be done at an endoscopy suite. At some centers, it is performed in an operation theater.When will I be discharged after POEM?
This varies with the center where you undergo the procedure. Most of the centers discharge their patients by day 4 post procedure. When will I be able to restart taking oral feeds?
You may be initiated on liquids on day 2 and solid foods on day 3.What are the complications of POEM?
POEM is a relatively safe procedure. No case of mortality has been reported from any part of the world till date. Minor injuries to the mucosa, i.e. the protective inner lining of the esophagus, entry of air or carbon dioxide into body cavity (events called surgical emphysema, pneumoperitoneum etc.) and minor bleeding are some of the common adverse events and most of these can be corrected without intervention. There are rare chances of severe complications like perforation of the esophagus, damage to nearby organs such as lungs, blood vessels etc. But in the hands of an expert endoscopist and vigilant anesthesiologist, you are usually safe during POEM.