Peroral endoscopic myotomy (POEM) for Achalasia
At a Glance:
What is peroral endoscopic myotomy (POEM)?
POEM is an endoscopic procedure that is performed for the treatment of certain disorders of swallowing. It is performed using a high-definition upper endoscope in the endoscopy unit of a hospital.
An endoscope is a flexible tubular instrument that can be passed through the mouth or rectum to visualize and treat medical conditions of the inner surfaces of the structures like the food pipe i.e esophagus, stomach, intestine, and colon.
What are the indications of POEM?
POEM is generally indicated for treating the following disease:
Achalasia: It is a medical condition that affects the muscles of the esophagus. The lower esophageal sphincter (LES), a muscularvalve present between the esophagus and the stomach fails to relax during swallowing in this condition. Consequently, the food doesn’t move forward into the stomach from the esophagus. The common symptoms of achalasia are:
- chest pain
- vomiting of undigested food
- weight loss
Achalasia can be corrected by cutting the muscles of the esophageal sphincter surgically and the procedure is known as myotomy. Peroral endoscopic myotomy (POEM) is a newer technique for the surgical management of achalasia with an endoscopic approach.
Diffuse esophageal spasm: Esophageal disorders of muscle spasm that are unresponsive to medical therapies
Nutcracker esophagus also known as hypertensive peristalsis is a muscle spasm disorder which needs surgical correction.
Can every person with achalasia undergo POEM, what are the contraindications?
Even though POEM is a safe and effective procedure, it may not be a suitable option in certain cases. Persons with any of the following conditions are generally not recommended to undergo POEM for achalasia:
- Disorders of coagulation
- History of any kind of therapy that is likely to compromise the integrity of the mucosa of the esophagus or lead to fibrosis of the submucosa for e.g. radiation for cancer treatment, endoscopic mucosal resection, or radiofrequency ablation
- Liver cirrhosis with portal hypertension
- Severe erosive esophagitis
How long does POEM surgery take?
POEM is a minimally invasive procedure that can be done in two to three hours approximately. A person may be expected to stay in the hospital for a period of two to three days during which he/she is monitored by the treating gastroenterologist and administered intravenous medications like antibiotics.
What to expect before POEM?
To ensure optimized patient outcomes, accurate diagnosis of achalasia or a spastic esophageal disorder is essential. Perioperative evaluation of the person is done by the doctors on the basis of the following investigation and information:
Clinical history and physical examination: A standardized, validated symptom assessment methodology called the Eckardt score or grading system is followed by doctors to diagnose and determine the severity of achalasia. The final score of the person is the sum of the individual ratings for each symptom/sign.
The Eckardt Score for Achalasia Severity:
|Signs/Symptoms||Score for each symptom/sign|
|Recent Weight loss(kg)||None||< 5||5 – 10||> 10|
|Chest pain||None||Occasional||Daily||Several times per day|
Tests: Some of the undermentioned tests may be advised by the treating gastroenterologist to confirm the diagnosis of achalasia before the procedure is undertaken.
Esophageal manometry: A high-resolution esophageal manometry test is done on an outpatient basis for the detection of problems pertaining to movement and pressure within the esophagus. Such problems may be the underlying cause of symptoms. The strength and muscle coordination of the esophagus during swallowing is measured by manometry.
Contrast esophagram: It is a diagnostic radiology examination for the upper gastrointestinal (GI) tract that includes parts like the esophagus, throat, and back of the mouth. This test is done using X-rays or an X-ray video (fluoroscopy). Also known as barium swallow, a contrast esophagram helps the doctors in diagnosing structural or functional issues of the upper GI tract like achalasia, ulcers, dysphagia, hiatal hernia, tumors or cancers, etc.
In some persons, barium may cause constipation. Hence it is recommended to drink plenty of fluids and high fiber food to facilitate the movement of the barium through the gastrointestinal tract. It is usually advised to not eat or drink anything after midnight of the night before the exam.
Esophagogastroduodenoscopy (EGD): In this diagnostic procedure a small flexible tube fitted with a camera, known as the endoscope, is introduced through the mouth or the nose and advanced to the esophagus and duodenum through the upper GI tract. Depending on the condition of the person, the procedure may be performed under moderate sedation or with topical anesthesia. General anesthesia is generally reserved for persons who are unlikely to tolerate the procedure while awake. This procedure helps in ruling out other conditions like cancer of the esophagus.
pH studies: Prolonged esophageal pH monitoring is not done in every case. However, in certain cases, it may be advised to rule out other problems like gastroesophageal reflux disease.
How is the POEM procedure done?
Before the procedure is undertaken, the doctor would advise specific preparatory instructions depending on the person’s medical status. Some of the commonly advised preparatory instructions are as follows:
- A liquid diet for a day or two days prior to the procedure.
- To clear the esophagus of food products, it is recommended not to eat or drink for 12 hours prior to the procedure.
- The doctor’s instructions regarding any prescription medication that a person may be on should be adhered to. For example, if a person is on an anticoagulant or antiplatelet medication, he/she may be advised to stop it prior to the procedure.
- The person may be placed on antibiotics prior to the procedure.
- Any allergies should be disclosed to the treating doctor during the medical history.
During POEM procedure:
- An IV line is usually inserted into the vein for the administration of fluids and antibiotics if required. Similarly, an arterial line too may be inserted to monitor the pressure during the procedure.
- Once the person is ready, an endoscope is passed through the mouth and into the esophagus till the site of the defect. The images are observed on a nearby monitor.
- No incisions or cuts are made outside the gastrointestinal tract.
- Operative technique: The POEM procedure is carried out in four consecutive steps namely:
- Mucosal incision and entry into the submucosa
- Creation of a submucosal tunnel
- Closure of the mucosal incision
- An initial incision is made in the internal lining of the esophagus to allow the entry of the endoscope inside the wall of the esophagus to expose the muscle.
- Once the muscle is reached, its inner layer near the lower esophageal sphincter is cut, termed as “myotomy”.
- The esophageal incision is closed with endoscopic clips after the myotomy.
Recovery after POEM
In case anesthesia is administered, some time is required to allow for recovery in the endoscopy unit. The person may be admitted to the hospital for monitoring and administration of any prescribed intravenous medications like antibiotics for a day or two. The doctor may advise a person to be nil by mouth i.e. not to eat anything on the night of the procedure.
A barium swallow is usually advised the next day morning. Depending on the outcome of the test, the person may be allowed to drink liquids and then advance to a soft diet the following day.
We obtain an esophagram on the day after the procedure to exclude an esophageal leak, after which a soft diet is allowed. Patients are advised to remain on a soft diet for 10 to 14 days before starting a regular diet.
Once discharged from the hospital, a person may be placed on prescription medications like antibiotics or antacids for a few days.
It is highly recommended to follow up with the gastroenterologist in the OPD as advised at the time of discharge. Another barium swallow study after a few months may be advised to ascertain that the esophagus empties well.
Is POEM safe, are there any risks?
When performed by an experienced gastroenterologist, POEM is a safe procedure. It is usually associated with a low rate of postoperative adverse events. As per the available scientific literature, the incidence of procedure-related adverse events in POEM is extremely low which is approximately 8%. Most of the complications that occur after POEM are relatively mild and easy to be managed expectantly, medically, or endoscopically. However, as with any surgery, there may be general and specific individual risks. Some of the commonly encountered risks are:
Side effects of anesthesia that may include:
- Heart attack or stroke in extremely rare cases
- Sore throat, due to the breathing tube if used during surgery
Specific risks associated with the procedure include:
- Subcutaneous emphysema
- Gastroesophageal reflux
What is the success rate of POEM?
Studies have shown that POEM is a safe and effective procedure. The response of the procedure in individuals with achalasia cardia is durable. The outcomes of POEM are not influenced by a history of any prior treatment. Available literature shows that patients in the range of 4 to 77 years with a mean age of 40 have undergone the procedure with a 97% completion rate. Clinical success rates at 1, 2 and 3 years are 94 %, 91 %, and 90 %, respectively.
G-POEM for gastroparesis
Endoscopic pyloromyotomy (G-POEM): This procedure is usually advised for the treatment of gastroparesis. In this procedure, instead of the lower esophageal sphincter in POEM, myotomy of the pylorus is done. The surgical procedure for G-POEM is similar to that of POEM.
Gastroparesis is a syndrome that results in delayed gastric emptying i.e. the inability of the stomach to empty itself of food normally. The hallmark of this condition is the absence of mechanical obstruction. Some of the symptoms which the condition usually presents are:
- Early satiety
- Upper abdominal pain
In most of the cases of gastroparesis the etiology or the causative factors may be unknown (or idiopathic), diabetes, or postsurgical.
What are the benefits of POEM?
For a person undergoing the procedure, one of the main advantages of POEM for the treatment of swallowing disorders is that there is no requirement of incisions in the chest or abdomen. Another advantage is minimal or sometimes no hospital stay after the procedure. Endoscopic procedures usually result in negligible complications and faster recovery.
Some of the advantages of POEM experienced by doctors include:
- Better control over the length and orientation of the myotomy
- Reduced risk of extraesophageal injury to the surrounding structures like nerves. For example, vagal nerve
- Repeat POEM and salvage laparoscopic myotomy are feasible in case of an unsuccessful initial POEM.
- Treatment of certain other conditions like a diffuse esophageal spasm that is not amenable to laparoscopic surgery is also an option.
How should one choose a facility for POEM?
The choice of facility for availing treatment of conditions like achalasia eventually depends on the person and his/her family and medical needs. However, an informed decision must be taken after considering the availability of the required expertise and infrastructure in the preferred facility.
Advanced procedures like POEM should be performed in high-volume centers of excellence with a one-stop availability of advanced diagnostic techniques like high-resolution manometry, fully equipped endoscopic suite, technique trained and experienced gastroenterologists and support staff.
Persons with swallowing disorders often have special nutritional and lifestyle needs. Nutrition plays a large role in the management of the symptoms of an esophagus or swallowing disorder. Led by gastroenterologists trained and experienced in procedures like POEM, the Center for Gastroenterology at Yashoda hospital, Hyderabad offers comprehensive services comprising of specialized teams for nutrition therapy, intestinal rehabilitation, and nutrition support for persons suffering from swallowing disorders.
Surgical myotomy considered to be the treatment of choice for persons with achalasia and certain disorders of swallowing. However, with advancements in surgical techniques, there are lesser invasive options now available for individuals to consider. Procedures like balloon dilatation or injection of Botox provide sustainable relief in certain cases but they also have a disadvantage of short-term results and the need for repeat interventions. Scar tissue formed due to these interventions can complicate a future laparoscopic repair as the chances of perforation increase. This makes complete myotomy difficult.
Peroral endoscopic myotomy (POEM), a newer option that can overcome these constraints is now available in specialized centers. POEM utilizes the advanced endoscopic technique of submucosal tunneling and is a totally endoscopic procedure.
Advantages of the endoscopic myotomy are shorter recovery time, a lower rate of complications and better treatment outcomes.
- US National Library of Medicine. Swanstrom LL, Kurian A, Dunst CM, Sharata A, Bhayani N, Rieder E. Long-term outcomes of an endoscopic myotomy for achalasia: the POEM procedure. Ann Surg. 2012 Oct;256(4):659-67. Available at: https://www.ncbi.nlm.nih.gov/pubmed/22982946. Accessed on November 22, 2019
- US National Library of Medicine.Per-oral endoscopic myotomy for achalasia cardia: outcomes in over 400 consecutive patients; Zaheer Nabi, Mohan Ramchandani, Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5419844/pdf/10-1055-s-0043-105517.pdf. Accessed on November 22, 2019
- Mayo Clinic. Evaluating the role of peroral endoscopic myotomy in the treatment of achalasia. Available at: https://www.mayoclinic.org/medical-professionals/digestive-diseases/news/evaluating-the-role-of-peroral-endoscopic-myotomy-in-the-treatment-of-achalasia/mac-20442373. Accessed on November 22, 2019
- Cleveland Clinic. POEM (Peroral Endoscopic Myotomy): A Systematic Review and Meta-analysis. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6009090/. Accessed on October 19,2019
- GISurgery Info.Evaluating the role of peroral endoscopic myotomy in the treatment of achalasia.Available at:http://gisurgery.info/classiinfo/37/32.%20The%20Eckardt%20Score.pdf.Accessed on October 19,2019
- US National Library of Medicine.Predictors of outcome in patients with achalasia treated by pneumatic dilation. Eckardt VF1, Aignherr C, Bernhard G.
About Author –
Specialized in general, laparoscopic and minimal access surgeries and procedures for problems of gastroenterology such as cancers, piles, fistula, hernia, gallstones, liver and pancreatic problems.