Endoscopic resection of gastrointestinal lesions: Preference and feasibility of en bloc resection techniques

Gastrointestinal (GI) malignancies, including esophageal, gastric, and colorectal cancers, constitute over a quarter of newly diagnosed cancers globally and contribute significantly to cancer-related deaths. Despite advancements in population-wide screening, early detection of these malignancies, particularly in asymptomatic individuals, remains challenging. Currently, the primary diagnostic modality relies on endoscopic evaluation, which necessitates the differentiation of lesions ranging from benign polyps to malignant masses. This differentiation is crucial since unnecessary surgeries for non-malignant lesions can lead to significant morbidity, mortality, and healthcare cost burdens.

Advancements in endoscopic resection techniques have evolved over the last two decades, enabling more precise and targeted resections. These techniques include simple polypectomy, endoscopic mucosal resection (EMR), endoscopic submucosal dissection (ESD), and endoscopic full thickness resection (EFTR). Among these, ESD has emerged as the preferred method for complex lesion resection due to its ability to achieve en bloc resection regardless of tumor size and fibrosis. However, the widespread implementation of ESD, particularly in North America, is hindered by its steep learning curve and limited availability of experts.

Methods and Techniques

EMR involves lifting the lesion submucosally and resecting it with a snare, often leading to piecemeal resection and increased recurrence rates. ESD, on the other hand, circumferentially marks the lesion, injects a lifting agent into the submucosa, and dissects the lesion using an electrosurgical knife, allowing for en bloc resection. EFTR involves full-thickness excision of GI tract lesions but is generally limited to lesions ≤2 cm due to technical constraints.

The choice of resection method depends on the lesion's morphology, size, and invasion depth. Endoscopic classifications such as the Paris Classification, the Japanese universal NBI magnifying endoscopic (JNET) classification, and the lateral spreading tumor (LST) subtypes provide valuable tools for assessing lesion architecture and risk of deep invasion.

Absolute Indications for ESD

The absolute indications for ESD vary based on the location of the GI lesion and endoscopy society guidelines. For esophageal lesions, ESD is indicated for high-grade dysplasia to moderately differentiated adenocarcinoma T1a (m1-m3) lesions >15 mm, as well as ESCCs with moderate to well-differentiated histology and limited circumferential involvement. In the stomach, ESD is recommended for mucosal adenocarcinomas, lesions with high-grade dysplasia, and larger lesions with certain characteristics. For colonic lesions, ESD is indicated for those with a high risk of submucosal invasion, such as LST-NG, lesions with a disorganized pit pattern, or protruding lesions suspicious for carcinoma.

Feasibility of EMR

Although ESD is the preferred method for certain lesions, EMR can be a viable alternative in select scenarios due to its wider availability and easier learning curve. EMR can be used for smaller lesions, such as those ≤10 mm in size, or when ESD expertise is not readily available. In these cases, careful ablation of clean margins during piecemeal resection can help reduce recurrence rates.

Conclusions

Endoscopic resection techniques have significantly advanced in recent years, enabling more precise and targeted resection of GI lesions. ESD, with its ability to achieve en bloc resection, is the preferred method for complex lesions; however, its widespread implementation in North America is limited. EMR, although associated with higher recurrence rates, can be a feasible alternative in select scenarios due to its wider availability and ease of learning. Careful assessment of lesion morphology, size, and invasion depth, along with the utilization of endoscopic classifications, can guide the selection of the most appropriate resection method, optimizing patient outcomes and reducing healthcare costs.

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https://www.xiahepublishing.com/2994-8754/JTG-2023-00001

The study was recently published in the Journal of Translational Gastroenterology.

Journal of Translational Gastroenterology (JTG) dedicates to improving clinical diagnosis and treatment, advancing understanding of the molecular mechanisms, and promoting translation from bench to bedside of gastrointestinal, hepatobiliary, and pancreatic diseases. The aim of JTG is to provide a forum for the exchange of ideas and concepts on basic, translational, and clinical aspects of gastroenterology, and promote cross-disciplinary research and collaboration.

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