Peroral Endoscopic Myotomy (POEM) For The Treatment Of Achalasia: A Retrospective And Prospective Multicenter Registry.

Our institution performs therapeutic Interventional Endoscopy in around 700-1000 patients a year. We come across several patients with esophageal disorders, including esophageal cancer and Achalasia.

Achalasia is an uncommon esophageal motility disorder caused by the inability of the lower esophageal sphincter (LES) to relax due to the degeneration of inhibitory neurons in the myenteric plexus. (1,2) Evidence of achalasia in patients includes the absence of relaxation in the LES, abnormal swallowing relaxation of the LES, or the absence of peristalsis in the esophageal body.

(2,3 ) Treatments for achalasia primarily focus on forcing the relaxation of the LES. Conventional treatments such as botolinum toxin (Botox) injections, balloon dilation, nitrate and calcium antagonists, and Heller myotomy, although effective, have many disadvantages. (4,5, 6) Balloon dilation, which is the least noninvasive out of the non-surgical processes, can still result in esophageal perforation and its long term investigations have reported unfavorable (2). Surgical myotomies, such as Heller myotomy and laproscopic esophagomytomy, are indicated when non-surgical therapies render ineffective.

However, gastroesophageal reflux disease occurs in 30% (7) of Heller Myotomy patients and it has a 10-15% failure rate (8). Per-oral endoscopic myotomy (POEM), derived from Advances in Natural Orifice Transluminal Endoscopic Surgery (NOTES) and advances in submucosal dissection (9,10,11), presents a novel, less invasive, and permanent treatment to lower esophageal sphincter pressure (12). POEM was first described by Parischa et al in porcine models in 2007 and its introduction into clinical care in 17 patients was made by Inoue et al in 2010. (12,13) POEM is performed entirely endoscopically, enabling much deeper incisions in the thoracic esophagus than surgery is able to create. (2 , 13) An incision is made in the mid- esophagus by creating a submucosal tunnel to access the muscle layer all the way down to the gastric cardia and conduct myotomy (partial muscle removal). Partial inner circular muscle layer is removed from the last part of the esophagus, lower esophageal sphincter and the upper part of the stomach. After the myotomy is completed, endoclips are used to seal the incision and the endoscope is withdrawn. (2) The effectiveness of POEM is indicated by patient studies based mostly in Europe and Asia. Recent studies report POEM has a 90% effectiveness rate compared to patients who have undergone Heller myotomy. (9 ,14,15) Based on study design and results of the recent studies done in Europe and Asia (retrospective only), we would like to evaluate and verify technical feasibility, clinical success and safety of clinically indicated POEM for Achalasia prospectively with a longer follow up duration (more than 6 months). Evaluation of these factors would help us compare them to conventional treatment modalities within our current facility; and consequently help us identify appropriate treatment techniques and improve clinical management of patients at WCMC-NYPH. The purpose of this retrospective and prospective registry is to assess long term data on efficacy, safety and clinical outcome of POEM. The registry will evaluate technical feasibility, clinical outcome, safety profile and overall clinical management through medical chart review.

The procedures we are evaluating are all clinically indicated and will not be prescribed to someone to participate in this registry study.