Submucosal endoscopy: the present and future

A review of techniques of third space endoscopy for gastrointestinal tumors

Purpose of review

This review explores the evolving landscape of third-space endoscopy (TSE) techniques for the management of gastrointestinal (GI) tumors. With rapid technological advances and accumulating evidence, there is a pressing need to synthesize current knowledge and clarify the comparative utility of approaches like submucosal tunneling endoscopic resection (STER) and tunneling endoscopic submucosal dissection (ESD).

Recent findings

STER is safe and effective for resection of subepithelial lesions, offering mucosal preservation, high en bloc resection rates, and reduced recovery time compared to ESE, ESD, and endoscopic full-thickness resection. Piecemeal STER is a potential alternative to surgery in managing large esophageal sub-epithelial lesions without compromising outcomes. For early epithelial neoplasms, pocket-creation and tunneling variants of ESD improve dissection speed and reduce adverse events, especially in large lesions. Comparative studies across esophagus, stomach, and colon confirm these benefits. Additionally, risk scoring systems and resection algorithms may guide personalized technique selection.

Summary

STER and tunneling ESD represent significant advances in minimally invasive management of GI tumors. Incorporating these techniques into practice can enhance safety and efficacy, especially when guided by risk stratification tools. Ongoing innovation, including artificial intelligence and robotics, is likely to further refine third-space interventions in near future.

Therapeutic endoscopy: Recent updates and future directions

The landscape of therapeutic endoscopy has undergone a remarkable evolution over the past few decades, carving out a niche that merges innovative technology with advanced clinical practice. As we venture further into the 21st century, the horizon of this field continues to expand, driven by rapid advancements in technology and a deeper understanding of gastrointestinal pathology. This review article aims to shed light on the recent advances and future trajectories of therapeutic endoscopy, focusing on pivotal areas such as third space endoscopy, endoscopic resection techniques, artificial endoscopy, endoscopic ultrasound (EUS), the integration of artificial intelligence (AI), and endoscopic anti-reflux therapies.

Emerging indications for third space endoscopy

This chapter will explore the recent advancements and innovations in the field of third space endoscopy. The traditional principles of per-oral endoscopic myotomy and endoscopic submucosal dissection have been applied to offer solutions to traditionally difficult to manage problems including esophageal diverticula, post-fundoplication dysphagia, post-sleeve gastrectomy stricture, bariatric procedure and Hirschsprung disease. Typically, these problems were managed surgically with potentially high rates of morbidity and mortality; however, the principles of third space endoscopy offer a safer and less invasive option for management. All of these applications of third space endoscopy are less than a decade old with some emerging in the last 1-2 years. In this chapter, we will explore the pathophysiology of these diseases and how third space endoscopy can offer a solution. We will also review the relevant literature along with the safety and effectiveness of the proposed innovations.

Endoscopic full thickness resection: techniques, applications, outcomes

INTRODUCTION

Endoscopic full-thickness resection (EFTR) represents a pivotal advancement in the minimally invasive treatment of gastrointestinal lesions, offering a novel approach for the management of lesions previously deemed challenging or unreachable through conventional endoscopic techniques.

AREAS COVERED

This review discusses the development, methodologies, applications, and clinical outcomes associated with EFTR, including exposed and device-assisted EFTR, the integration of endoscopic mucosal resection with EFTR in hybrid techniques, and the collaborative approach between laparoscopic and endoscopic surgery (LECS). It encapsulates a comprehensive analysis of the various EFTR techniques tailored to specific lesion characteristics and anatomical locations, underscoring the significance of technique selection based on the lesion's nature and situational context.

EXPERT OPINION/COMMENTARY

The review underscores EFTR's transformative role in expanding therapeutic horizons for gastrointestinal tumors, emphasizing the importance of technique selection tailored to the unique attributes of each lesion. It highlights EFTR's capacity to facilitate organ-preserving interventions, thereby significantly enhancing patient outcomes and reducing procedural complications. EFTR is a cornerstone in the evolution of gastrointestinal surgery, marking a significant leap forward in the pursuit of precision, safety, and efficacy in tumor management.

The role of cap-assisted endoscopy and its future implications

Cap-assisted endoscopy refers to a procedure in which a short tube made of a polymer (mostly transparent) is attached to the distal tip of the endoscope to enhance its diagnostic and therapeutic capabilities. It is reported to be particularly useful in: (1) minimizing blind spots during screening colonoscopy, (2) providing a constant distance from a lesion for clear visualization during magnifying endoscopy, (3) accurately assessing the size of various gastrointestinal lesions, (4) preventing mucosal injury during foreign body removal, (5) securing adequate workspace in the submucosal space during endoscopic submucosal dissection or third space endoscopy, (6) providing an optimal approach angle to a target, and (7) suctioning mucosal and submucosal tissue with negative pressure for resection or approximation. Here, we review various applications of attachable caps in diagnostic and therapeutic endoscopy and their future implications.

Prevalence, natural progression, and clinical practices of upper gastrointestinal subepithelial lesions in Korea: a multicenter study

BACKGROUND/AIMS

This study aimed to evaluate the prevalence and natural progression of subepithelial lesions (SELs) in the upper gastrointestinal (UGI) tract.

METHODS

The medical records of patients with UGI SELs who underwent endoscopic screening at eight university hospitals between January and December 2010 were retrospectively investigated. The follow-up evaluations were performed until December 2016.

RESULTS

UGI SELs were found in 1,044 of the 65,233 participants screened (endoscopic prevalence, 1.60%; the total number of lesions, 1,062; mean age, 55.1±11.2 years; men, 53.6%). The median follow-up period was 48 (range, 8-74) months. SELs were most frequently found in the stomach (63.8%) and had a mean size of 9.9±6.1 mm. Endoscopic ultrasonography (EUS) was performed in 293 patients (28.1%). The most common lesions were leiomyomas, followed by gastrointestinal stromal tumors (GISTs), and ectopic pancreas. The proportions of SELs with malignant potential according to size were 3% (<1 cm), 22% (1-2 cm), 27% (2-3 cm), and 38% (≥3 cm). In gastric SELs larger than 1 cm, resections were performed in 20 patients because of an increase in size, of which 12 were found to be GISTs.

CONCLUSION

The prevalence of UGI SELs was 1.60%. Further, 23% of gastric SELs ≥1 cm were precancerous lesions, most followed by EUS and clinical decisions without initial pathological confirmation.

Precision Endoscopy in Peroral Myotomies for Motility Disorders of the Upper Gastrointestinal Tract: Current Insights and Prospective Avenues-A Comprehensive Review

Our review delves into the realm of peroral endoscopic myotomies (POEMs) in the upper gastrointestinal tract (UGT). In recent years, POEMs have brought about a revolution in the treatment of UGT motility disorders. Esophageal POEM, the first to be introduced, has now been validated as the primary treatment for achalasia. Subsequently developed, G-POEM displays promising results in addressing refractory gastroparesis. Over time, multiple endoscopic myotomy techniques have emerged for the treatment of Zenker's diverticulum, including Z-POEM, POES, and hybrid approaches. Despite the well-established efficacy outcomes, new challenges arise in the realm of POEMs in the UGT. For esophageal POEM, the future scenario lies in customizing the myotomy extent to the minimum necessary, while for G-POEM, it involves identifying patients who can optimally benefit from the treatment. For ZD, it is crucial to validate an algorithm that considers various myotomy options according to the diverticulum's size and in relation to individual patients. These challenges align with the concept of precision endoscopy, personalizing the technique for each subject. Within our text, we comprehensively examine each myotomy technique, analyzing indications, outcomes, and adverse events. Additionally, we explore the emerging challenges posed by myotomies within the context of the evolving field of precision endoscopy.