Education and Imaging. Gastroenterology: Histopathological investigation of distal esophageal spasm (DES) using per-oral endoscopic myotomy (POEM)

Peroral endoscopic myotomy: techniques and outcomes

Achalasia is progressive neurodegenerative disorder of the esophagus, resulting in uncoordinated esophageal motility and failure of lower esophageal sphincter relaxation, leading to impaired swallowing. Surgical myotomy of the lower esophageal sphincter, either open or minimally invasive, has been a standard of care for the past several decades. Recently, new procedure-peroral endoscopic myotomy (POEM) has been introduced into clinical practice. This procedure accomplishes the same objective of controlled myotomy only via endoscopic approach. In the current chapter authors review the present state, clinical applications, outcomes and future directions of the POEM procedure.

Neuronal Control of Esophageal Peristalsis and Its Role in Esophageal Disease

PURPOSE OF REVIEW

Esophageal peristalsis is a highly sophisticated function that involves the coordinated contraction and relaxation of striated and smooth muscles in a cephalocaudal fashion, under the control of central and peripheral neuronal mechanisms and a number of neurotransmitters. Esophageal peristalsis is determined by the balance of the intrinsic excitatory cholinergic, inhibitory nitrergic and post-inhibitory rebound excitatory output to the esophageal musculature.

RECENT FINDINGS

Dissociation of the longitudinal and circular muscle contractions characterizes different major esophageal disorders and leads to esophageal symptoms. Provocative testing during esophageal high-resolution manometry is commonly employed to assess esophageal body peristaltic reserve and underpin clinical diagnosis. Herein, we summarize the main factors that determine esophageal peristalsis and examine their role in major and minor esophageal motility disorders and eosinophilic esophagitis.

Endoscopic foregut surgery and interventions: The future is now. The state-of-the-art and my personal journey

In this paper, I reviewed the emerging field of endoscopic surgery and present data supporting the contention that endoscopy can now be used to treat many foregut diseases that have been traditionally treated surgically. Within each topic, the content will progress as follows: "lessons learned", "technical considerations" and "future opportunities". Lessons learned will provide a brief background and update on the most current literature. Technical considerations will include my personal experience, including tips and tricks that I have learned over the years. Finally, future opportunities will address current unmet needs and potential new areas of development. The foregut is defined as "the upper part of the embryonic alimentary canal from which the pharynx, esophagus, lung, stomach, liver, pancreas, and part of the duodenum develop". Foregut surgery is well established in treating conditions such as gastroesophageal reflux disease (GERD), achalasia, esophageal diverticula, Barrett's esophagus (BE) and esophageal cancer, stomach cancer, gastric-outlet obstruction, and obesity. Over the past decade, remarkable progress in interventional endoscopy has culminated in the conceptualization and practice of endoscopic foregut surgery for various clinical conditions summarized in this paper. Regarding GERD, there are now several technologies available to effectively treat it and potentially eliminate symptoms, and the need for long-term treatment with proton pump inhibitors. For the first time, fundoplication can be performed without the need for open or laparoscopic surgery. Long-term data going out 5-10 years are now emerging showing extended durability. In respect to achalasia, per-oral endoscopic myotomy (POEM) which was developed in Japan, has become an alternative to the traditional Heller's myotomy. Recent meta-analysis show that POEM may have better results than Heller, but the issue of post-POEM GERD still needs to be addressed. There is now a resurgence of endoscopic treatment of Zenker's diverticula with improved technique (Z-POEM) and equipment; thus, patients are choosing flexible endoscopic treatment as opposed to open or rigid endoscopy options. In regard to BE, endoscopic submucosal dissection (ESD) which is well established in Asia, is now becoming more mainstream in the West for the treatment of BE with high grade dysplasia, as well as early esophageal cancer. In combination with all the ablation technologies (radiofrequency ablation, cryotherapy, hybrid argon plasma coagulation), the entire spectrum of Barrett's and related dysplasia and early cancer can be managed predominantly by endoscopy. Importantly, in regard to early gastric cancer and submucosal tumors (SMTs) of the stomach, ESD and full thickness resection (FTR) can excise these lesions en-bloc and endoscopic suturing is now used to close large defects and perforations. For treatment of patients with malignant gastric outlet obstruction (GOO), endoscopic gastro-jejunostomy is now showing better results than enteral stenting. G-POEM is also emerging as a treatment option for patients with gastroparesis. Obesity has become an epidemic in many western countries and is becoming also prevalent in Asia. Endoscopic sleeve gastroplasty (ESG) is now becoming an established treatment option, especially for obese patients with body mass index between 30 and 35. Data show an average weight loss of 16 kg after ESG with long-term data confirming sustainability. Finally, in respect to endo-hepatology, there are many new endoscopic interventions that have been developed for patients with liver disease. Endoscopic ultrasound (EUS)-guided liver biopsy and EUS-guided portal pressure measurement are exciting new frontiers for the endo-hepatologists.

A clinical study of peroral endoscopic myotomy reveals that impaired lower esophageal sphincter relaxation in achalasia is not only defined by high-resolution manometry

Background and aim

Achalasia is an esophageal motility disorder characterized by impaired lower esophageal sphincter (LES) relaxation. On high-resolution manometry (HRM), impaired LES relaxation is defined by elevated integrated relaxation pressure (IRP). However, a new category of achalasia within the normal IRP range has been suggested.

Methods

HRM was performed using a Starlet device and an IRP threshold of 26 mmHg. Peroral endoscopic myotomy (POEM) was performed for cases of achalasia diagnosed using established methods. During POEM, the histology of the LES was assessed. Follow-up was performed 2 months post-operatively.

Results

Forty-one patients with achalasia (18 women, mean age 53 ± 18.6 years) were included. Among them, 27 were placed in the IRP > 26 mmHg subgroup (impaired LES relaxation on HRM) and 14 in the IRP ≤ 26 mmHg subgroup (normal LES relaxation on HRM). In the IRP ≤ 26 mmHg subgroup, patients were older, had longer symptom duration, and had more esophageal dilation. The IRP ≤ 26 mmHg subgroup had the same symptom severity as the higher IRP subgroup and POEM significantly improved symptoms and IRP, although four patients still had severe LES fibrosis.

Conclusions

The clinical presentation of achalasia has a gap between a HRM-defined impaired LES relaxation, with aging or disease progression considered reasons for a lowered LES pressure. POEM can be a feasible treatment option, even for cases of achalasia with a normal IRP. However, patients with severe LES fibrosis need more attention for the therapeutic indication.

Esophageal motility disorders: new perspectives from high-resolution manometry and histopathology

High-resolution manometry (HRM) and peroral endoscopic myotomy (POEM) have contributed significantly to the field of esophageal motility disorders in recent years. The development of HRM has categorized various esophageal motility disorders with a focus on a diverse range of manometric anomalies. Additionally, the Chicago classification criteria is widely used for manometric diagnosis. Moreover, POEM was introduced as a minimally invasive radical therapy for achalasia and shows promise for other spastic esophageal motility disorders as well. POEM has also enabled a transluminal endoscopic approach for determining the histology of the esophageal muscle layer, which is expected to assist in elucidating the etiology of disorders associated with esophageal motility. The purpose of this review is to update the diagnosis, pathology, and treatment of esophageal motility disorders, with a focus on the recent advances in this field.

Muscle layer histopathology and manometry pattern of primary esophageal motility disorders including achalasia

BACKGROUND

Histopathology of muscularis externa in primary esophageal motility disorders has been characterized previously. We aimed to correlate the results of high-resolution manometry with those of histopathology.

METHODS

During peroral endoscopic myotomy, peroral esophageal muscle biopsy was performed in patients with primary esophageal motility disorders. Immunohistochemical staining for c-kit was performed to assess the interstitial cells of Cajal (ICCs). Hematoxylin Eosin and Azan-Mallory staining were used to detect muscle atrophy, inflammation, and fibrosis, respectively.

KEY RESULTS

Slides from 30 patients with the following motility disorders were analyzed: achalasia (type I: 14, type II: 5, type III: 3), one diffuse esophageal spasm (DES), two outflow obstruction (OO), four jackhammer esophagus (JE), and one nutcracker esophagus (NE). ICCs were preserved in high numbers in type III achalasia (n=9.4±1.2 cells/high power field [HPF]), compared to types I (n=3.7±0.3 cells/HPF) and II (n=3.5±1.0 cells/HPF). Moreover, severe fibrosis was only observed in type I achalasia and not in other types of achalasia, OO, or DES. Four of five patients with JE and NE had severe inflammation with eosinophilic infiltration of the esophageal muscle layer (73.8±50.3 eosinophils/HPF) with no epithelial eosinophils. One patient with JE showed a visceral myopathy pattern.

CONCLUSIONS & INFERENCES

Compared to types I and II, type III achalasia showed preserved ICCs, with variable data regarding DES and OO. In disorders considered as primary esophageal motility disorders, a disease category exists, which shows eosinophilic infiltration in the esophageal muscle layer with no eosinophils in the epithelium.