LCD L38747: Peroral Endoscopic Myotomy (POEM)

Achalasia is a disorder of the esophagus that makes it difficult for food and liquid to pass into the stomach. Achalasia results from the degeneration of ganglion cells in the myenteric plexus in the wall of the esophagus. This degeneration leads to failure of relaxation of the lower esophageal sphincter (LES) together with loss of peristalsis in the distal esophagus. The most common symptoms in patients with achalasia are dysphagia for solids and liquids as well as regurgitation of undigested foods or saliva. Additional symptoms include chest pain, heartburn, and difficulty belching. Complications of achalasia may include progressive dilation of the esophagus (megaesophagus) possibly leading to esophagectomy. Patients with achalasia are also at increased risk of developing esophageal cancer. Achalasia can be treated with pneumatic dilatation (PD), botulinum toxin injection, and surgical myotomy. Laparoscopic Heller Myotomy (LHM) is the most common surgical myotomy procedure for treatment of achalasia.

Peroral Endoscopic Myotomy (POEM) is the endoscopic complement of surgical myotomy and is a newer, less invasive procedure for the management of achalasia. POEM is an endoscopic procedure, which creates a tunnel in the submucosal layer of the esophagus and proximal stomach. Through this submucosal tunnel, an esophageal and gastric myotomy are made using a flexible endoscope. 1 The POEM procedure is performed in 4 steps: 1) mucosal incision/entry into the submucosa, 2) creation of a submucosal tunnel, 3) myotomy, and 4) closure of the mucosal incision. 6,7,8,12,21,23,24,31

POEM is a form of natural orifice transluminal endoscopic surgery (NOTES). The procedure is performed perorally, without any incisions in the chest or abdomen. The advantage of this approach is to reduce procedure-related pain and return patients to regular activities sooner than surgeries requiring external incisions.

POEM may be considered medically necessary for treatment of symptomatic, monometrically proven primary idiopathic achalasia, types I, II, or III. Prior to performing a POEM procedure, it is crucial to confirm that patients have the correct diagnosis of achalasia and the following documentation must be included in the clinician’s preoperative evaluation:

• History and physical exam – in cluding a standardized, validated symptom assessment form completed by all patients (i.e., Eckardt score ≥3);

• High-resolution esophageal manometry (HRM) – achalasia is subclassified according to the Chicago Classification of esophageal motility disorders, which is based upon the result of a high-resolution esophageal manometry test;

• Contrast esophagram – findings on contrast esophagram that are suggestive of achalasia include a narrowed esophagogastric junction (EGJ) with a "bird-beak" appearance and esophageal aperistalsis. Late or end-stage achalasia may give the appearance that the esophagus is significantly dilated, angulated, and tortuous, giving it a sigmoid shape 35 ;

• E sophagogastroduodenoscopy (EGD) – EGD sometimes reveals a dilated esophagus that contains residual material with normal appearing esophageal mucosa.

Contraindications — if 1 of the following conditions is present, the patient should not undergo POEM:

• Severe erosive esophagitis

• Significant coagulation disorders

• Liver cirrhosis with portal hypertension

• Severe pulmonary disease

• Esophageal malignancy

• Prior therapy that may compromise the integrity of the esophageal mucosa or lead to submucosal fibrosis, including recent esophageal surgery, radiation, endoscopic mucosal resection, or radiofrequency ablation

Previous therapies for achalasia, such as PD, botulinum toxin injection, or LHM, are not contraindications to POEM.

Prior to treatment with POEM, patients should be educated on the risk of gastroesophageal reflux disease (GERD). Also, follow-up acid suppression treatment should be considered after POEM. Patients should be counseled that treatments exist with a lower incidence of post-procedure GERD, such as LHM and PD.

POEM is considered a safe but complex procedure. POEM will be considered medically reasonable and necessary only if it is performed by adequately trained, experienced physicians in high-volume centers. These centers must have the available staff to address any potential adverse events from POEM immediately, including but not limited to gastrointestinal or cardio-thoracic complications.

POEM appears to be highly beneficial in the short-term management of achalasia. According to a 2014 (Stavropoulos, et al.) Natural Orifice Surgery Consortium for Assessment and Research (NOSCAR) POEM White Paper Committee, clinical success, defined as a post-treatment Eckardt score of ≤3 and/or a >50% decrease in the LES pressure, was achieved in 82% to 100% of patients. 22

Additional studies documented similar patient improvements after POEM using either a timed barium esophagram or quality of life (QOL) assessment:

Sharata, et al. (2015) reported on a consecutive patient cohort with clinical and objective outcomes. 21 Comprehensive data was collected prospectively on all subjects undergoing POEM from October 2010 to November 2013 at a single institution. Subjects were classified based on HRM results. Operative data and immediate outcomes were reviewed. Symptom scores, HRM, and timed barium swallow (TBS) were performed prior to the procedure. Subjects were asked to undergo routine postoperative testing 6-12 months following surgery with the addition of standard 24-hour pH to the preoperative protocol. Morbidity was defined as requiring additional procedures or prolonged hospital stay >2 days. 100 POEM patients were included in the final analysis. The mean age was 58 years (18-83 years). Results demonstrated that the primary presenting symptoms included dysphagia 81, chest pain 10, and regurgitation 9. The mean follow-up was 16 months. HRM diagnoses were 75 achalasia (30 type I, 43 type II, 2 type III), 12 nutcracker esophagus, 5 diffuse esophageal spasm (DES), and 8 isolated hypertensive non-relaxing LES. The mean operative time was 128 minutes. The median hospital length of stay (LOS) was 1 day. The overall morbidity was 6%; all these patients were treated endoscopically or with conservative management without further sequelae. The average LES resting/residual pressure significantly decreased (44.3/22.2 to 19.6/11.7 in millimeters of mercury). Esophageal emptying improved from 40% to 90% on TBS with 93% patients demonstrating >90% emptying at 1 minute. Of the achalasia patients, 36% (17/47) showed some return of normal peristalsis (≥70% peristalsis) on post-op HRM. Abnormal acid exposure was present on postoperative testing in 38% of patients (26/68). Of these, 14 patients were asymptomatic. No reflux patient required any additional antireflux procedure. Eckardt scores decreased from 6 to 1. Dysphagia was improved or eliminated in 97% of patients with a complete resolution accomplished in 89%. Complete dysphagia relief was better for achalasia patients (46/47 patients; 97.8%) vs. non-achalasia patients (17/24; 70.8%). Of those with preoperative chest pain, 91.5% reported complete relief. 4 patients have refractory dysphagia. 2 non-achalasia patients underwent subsequent LHM and 2 are improved following serial endoscopic dilatations. Sharata, et al. were able to conclude that despite reflux in 1 out of 3 of patients, POEM provides excellent relief of dysphagia (97%) and chest pain (91.5%) for patients with esophageal spastic disorders with acceptable procedural morbidity.

Teitelbaum, et al. (2013) looked at the effect on anatomic and functional outcomes regarding the differences in POEM vs. LHM since an antireflux procedure is not performed in POEM with mobilization of the hiatus. 26 This study looked at patients who underwent LHM or POEM and had both a pre- and postoperative timed barium esophagogram (TBE). TBEs were performed with 200 mL of contrast, with radiographs taken at 1, 2, and 5 minutes. Results demonstrated that a total of 17 LHM and 12 POEM patients had undergone pre- and postoperative TBEs. Both groups had decreased column heights postoperatively at 1, 2, and 5 minutes (LHM: pre, 15.6, 12.7, 11.3 cm vs. post, 3.6, 2.5, 1.8 cm; P