Comparison of Methods for Removing Large Benign Broad-based Epithelial Neoplasms of the Colon: ESD and EMR.

Summary

Benign epithelial neoplasms of the colon are a significant problem of colorectal surgery and health care not only because of their malignant potential, but also because of their prevalence among the working-age population. Adenomas are more often detected in men than in women (OR = 1.77; 95% CI = 1.66-1.89), increasing in men from 25% at 50-54 years to 39% in people over 70 years old and in women from 15% at 50-54 years to 26% at 70 years of age (p \< 0.001) \[1\]. Colonoscopy is the gold standard among all methods for diagnosing adenomas and adenocarcinomas of the colon. Endoscopic removal of colorectal polyps reduces the incidence and mortality from colorectal cancer (CRC) and is considered a necessary skill for all endoscopists performing colonoscopy \[2, 6\]. Endoscopic mucosal resection (EMR) was developed in 1984 by M. Tada et al. as a new technique for removing epithelial lesions of the gastrointestinal tract \[181\]. There are a number of aspects that cause additional complications during mucosectomy, such as convergence of folds, localization of large polyps between two folds, tumor spread beyond two folds, which are factors in tumor fragmentation and require additional study of their impact on long-term treatment outcomes. It is important to note that removal of colon tumors by fragmentation technique is associated with increased recurrence rate, however, in most cases these recurrent lesions are small in size and can be easily removed during dynamic colonoscopy. Predictably high recurrence rate during tumor fragmentation during removal indicates non-radical nature of the intervention performed and safety of this manipulation should be proven. Endoscopic submucosal dissection (ESD) is a relatively new method for removing superficial gastrointestinal neoplasms and was described at the end of the 20th century \[85\]. The development of the submucosal dissection technique was motivated by the difficulty of removing formations larger than 20 mm in a single block by endoscopic resection of the mucosa. Also, the association of tumor fragmentation during resection with a high risk of local recurrence and the difficulty of morphological evaluation of the removed specimen \[133, 136, 190\]. However, endoscopic submucosal dissection is a lengthy and energy-consuming procedure. According to Japanese authors, the average time for endoscopic submucosal dissection is 48.5-60 min. \[77, 89\], and, according to European scientists, the time for performing such interventions ranges from 142 to 176 minutes \[7, 78, 144, 187\]. According to Japanese clinical guidelines, the preferred method for removing large epithelial neoplasms of the colon with suspected intramucosal invasion is ESD, and European and American guidelines talk about the possible use of EMR, including in parts. In addition, unlike Japanese guidelines, where it is considered unsafe to remove a neoplasm in parts in assessing its radicality, Western guidelines allow the use of EMR in parts. Thus, endoscopic resection of the mucous membrane and endoscopic dissection in the submucosal layer are currently successfully used in the treatment of epithelial formations, but the advantages and disadvantages of each technique for a particular type of neoplasm, its histological nature and localization require systematization and clarification. The place of endoscopic mucosal resection and submucosal dissection in the removal of epithelial lesions of the colon has not been definitively established. Technical aspects, risk factors for complications, and long-term results of these types of endoscopic interventions require additional analysis.

Endoscopic interventions on the colon are accompanied by a certain percentage of complications. The most common complications of endoscopic removal of colon neoplasms are bleeding and perforation, the frequency of which varies from 0.08% to 10% depending on the analyzed method and patient sample \[93, 120\]. Given the wide variability of the available data, the influence of various factors on the frequency of complications requires additional study due to the need to identify correctable variables.

In June 2022, a group of authors proposed to the world community of specialists a new classification of complications in endoluminal endoscopy of the gastrointestinal tract for standardized assessment and analysis of the safety of endoscopic interventions \[1\] - "AGREE" (acronym for Adverse events GastRointEstinal Endoscopy) The authors of the classification also recommend recording any complications that arise, both at the stage of preparation for the planned endoscopic intervention (regardless of whether it was ultimately performed or not), and in those30 days after the intervention.\[1\]. It is these provisions of the AGREE classification that remain controversial and require more careful discussion \[3\]. In any case, in our opinion, at least a cause-and-effect relationship should be established between the action and the complication.

Conditions

• Benign Colon Tumors

Interventions

PROCEDURE

EMR

3-4 ml of high-osmolar solution or saline solution stained with indigo carmine are introduced into the submucosal layer under the formation. The formation and the surrounding mucous membrane (at least 5 mm from the edge of the formation) are removed using a standard diathermic polypectomy loop available to the operator. The formation is removed using electric current in the EndocatQ mode. After the formation is removed, the resection site is examined in white light, then virtual chromoscopy (NBI), and then examined with magnification. If residual tissue of the formation is detected, it is removed using the same technique. If the removal of residual tissue of the formation was performed by another method, indicate which one and why. The removed formation is extracted using a snare loop; if it is removed in parts, then all fragments, if possible, are extracted through the aspiration channel of the endoscope; for large fragments, a snare loop is used.

PROCEDURE

ESD

After assessing the boundaries of the formation, a mark is made at least 5 mm from the edge, then a circular or semicircular incision of the mucosa is made, after which the formation is removed by dissection of the submucosal layer using a scarecrow knife, a knife with a ceramic head at the end in EndocutQ mode, spray-coag swift-coag. The EDPS technique - a tunnel method, will also be used where feasible. The essence of the technique is a semilunar incision of the mucous membrane, retreating from the marks, and creating a tunnel under the formation to the proximal edge of the marks, with subsequent cutting off of the formation along the edges. The removed neoplasm is extracted and stretched on a plate. After removal, the edges and bottom of the wound are assessed, if necessary, prophylactic coagulation of visible vessels and clipping are performed.

Sponsors & Collaborators

• Pirogov Russian National Research Medical University

  lead OTHER

Principal Investigators

• Evgeny Gorbachev · Pirogov Russian National Research Medical University

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

NONE

Model

PARALLEL

Eligibility

Min Age

18 Years

Max Age

100 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2023-12-10

Primary Completion

2025-12-31

Completion

2026-12-31

Countries

• Russia

Study Locations