What is the recommended approach for endoscopic mucosal resection (EMR) of a cecal polyp?

From the Guidelines

The recommended approach for endoscopic mucosal resection (EMR) of a cecal polyp is to employ the safest, most complete, and efficient resection techniques based on available evidence, with careful assessment of the polyp and consideration of its size, morphology, and surface patterns to determine resectability.

Key Steps in EMR of a Cecal Polyp

• Careful assessment of the polyp is essential, including evaluation of its size, morphology, and surface patterns to determine resectability 1.
• The procedure typically begins with submucosal injection using a solution such as normal saline mixed with epinephrine (1:100,000) and methylene blue or indigo carmine for better visualization.
• For the actual resection, a specialized snare is used to remove the polyp in one piece (en bloc) if smaller than 20mm, or in multiple pieces (piecemeal) for larger lesions.
• Carbon dioxide insufflation is preferred over air to reduce patient discomfort.
• Post-resection, the margins should be carefully inspected and any residual polyp tissue removed.
• Prophylactic closure of the defect with clips is often performed, particularly for larger lesions, to prevent delayed bleeding and perforation.
• The cecum's thin wall requires extra caution during EMR to avoid perforation.
• Complete retrieval of all polyp fragments is crucial for accurate histopathological assessment.
• Post-procedure, patients should be monitored for complications such as bleeding or perforation, with clear instructions provided regarding when to seek medical attention.

Considerations for Large Lesions

• For non-pedunculated lesions 20 mm or larger, EMR is recommended as the preferred treatment method, as it can provide complete resection and obviate the higher morbidity, mortality, and cost associated with alternative surgical treatment 1.
• An endoscopist experienced in advanced polypectomy should manage large non-pedunculated colorectal lesions.
• Snare resection of all grossly visible tissue of a lesion in a single colonoscopy session and in the safest minimum number of pieces is recommended, as prior failed attempts at resection are associated with higher risk for incomplete resection or recurrence.

Surveillance After EMR

• The need for ongoing colonoscopic surveillance should be determined by the colonoscopic findings at each surveillance procedure, using the same high-risk criteria to stratify risk 1.
• People with high-risk findings on a surveillance colonoscopy should undergo a further surveillance colonoscopy at an interval of 3 years.
• People with no high-risk findings on a surveillance colonoscopy should cease colonoscopic surveillance, but should participate in the national bowel screening programme when invited.

From the Research

Approach for EMR of Cecal Polyp

The recommended approach for endoscopic mucosal resection (EMR) of a cecal polyp depends on the size and characteristics of the polyp.

• For diminutive polyps (≤ 5 mm), cold snare polypectomy (CSP) is recommended due to its high rates of complete resection, adequate tissue sampling for histology, and low complication rates 2.
• For small polyps (6-9 mm), CSP is suggested because of its superior safety profile, although evidence comparing efficacy with hot snare polypectomy (HSP) is lacking 2.
• For nonpedunculated adenomatous polyps of 10-19 mm in size, hot snare polypectomy is recommended 3.
• For large (≥ 20 mm) nonpedunculated adenomatous polyps, conventional (diathermy-based) EMR is recommended 3.
• Underwater EMR can be considered an alternative to conventional hot EMR for the treatment of adenomatous polyps 3.
• Endoscopic submucosal dissection (ESD) may also be suggested as an alternative for removal of large polyps in selected cases and in high-volume centers 3.

Considerations for EMR

When performing EMR, it is essential to:

• Carefully assess the lesion prior to EMR to identify features suggestive of poor outcome, such as lesion size > 40 mm, ileocecal valve location, prior failed attempts at resection, and size, morphology, site, and access (SMSA) level 4 2.
• Achieve a completely snare-resected lesion in the safest minimum number of pieces, with adequate margins and without need for adjunctive ablative techniques 2.
• Treat the resection margins with thermal ablation using snare-tip soft coagulation to prevent adenoma recurrence after piecemeal EMR of large nonpedunculated adenomatous polyps 3.
• Consider prophylactic endoscopic clip closure of the mucosal defect after EMR of large nonpedunculated adenomatous polyps in the right colon to reduce the risk of delayed bleeding 3.