Endoscopic mucosal resection with an over-the-counter hyaluronate preparation

Update on Difficult Polypectomy Techniques

Endoscopists often encounter colon polyps that are technically difficult to resect. These lesions traditionally were managed surgically, with significant potential morbidity and mortality. Recent advances in endoscopic techniques and instruments have allowed endoscopists to safely and effectively remove colorectal lesions with high technical and clinical success and potentially avoid invasive surgery. Endoscopic mucosal resection (EMR) has gained acceptance as the first-line therapy for large colorectal lesions. Endoscopic submucosal dissection (ESD) has been reported to be associated with higher rate of en bloc resection and less risk of short-time recurrence, but with an increased risk of adverse events. Therefore, the role of colorectal ESD should be restricted to lesions with high-risk morphologic features of submucosal invasion. In this article, we review the recent literature on the endoscopic management of difficult colorectal neoplasms.

Endoscopic resection of colorectal lesions: The narrowing divide between East and West

Colonic polypectomy is an effective way of reducing colon cancer mortality. Multiple techniques now exist for the resection of polyps, and the endoscopist must decide on the appropriate resection approach for individual patients and lesions. This decision should maximize efficacy, safety and cost-effectiveness and provide optimal oncological outcomes while minimizing unnecessary surgical treatment. Advances in endoscopic imaging technology are improving the accuracy of endoscopic diagnosis and allowing more precise risk assessment of colonic lesions. Resection technique can be tailored to the endoscopic findings. Diminutive (≤5 mm) and small polyps (≤9 mm) are best resected primarily by snare techniques. Cold snare polypectomy has proven safety, but efficacy and technique require further study. There is variation in techniques used for polyps 6-20 mm in size and incomplete resection rates for conventional polypectomy may be considerable. Endoscopic mucosal resection (EMR) is well established, safe and effective for lesions without submucosal invasion (SMI); however, recurrence is a key limitation. Endoscopic submucosal dissection (ESD) is well established in the East; however, it is resource intensive and its role in lesions with a low risk of SMI is questionable. ESD in the West remains incompletely defined and is associated with high adverse event rates, but it is becoming increasingly available and successful as experience grows. Emerging full-thickness resection technologies are still in their infancy and remain experimental as a result of the absence of reliable closure devices and techniques. Patient-focused outcomes should guide technique selection.

Improved Techniques for Endoscopic Mucosal Resection (EMR) in Colorectal Adenoma

Background

Endoscopic therapy of colorectal adenomas and early cancers is a standard method. Besides oncological criteria, the method is limited by polyp location, size, and texture.

Method

Based on the current literature, technical modifications and developments in endoscopic mucosal resection are described.

Results

Numerous approaches exist to improve the conditions of resection, including optimisation of mucosal elevation and modification of techniques, tools, and devices.

Conclusion

Endoscopic therapy of sessile and flat colorectal polyps remains a challenge. Some of the presented modifications can help to address this challenge.

Endoscopic mucosal resection

EMR has become an established therapeutic option for premalignant and early-stage GI malignancies, particularly in the esophagus and colon. EMR can also aid in the diagnosis and therapy of subepithelial lesions localized to the muscularis mucosa or submucosa. Several dedicated EMR devices are available to facilitate these procedures. Adverse event rates, particularly bleeding and perforation, are higher after EMR relative to other basic endoscopic interventions but lower than adverse event rates for ESD. Endoscopists performing EMR should be knowledgeable and skilled in managing potential adverse events resulting from EMR.

Endoscopic management of nonlifting colon polyps

Background and Study Aims. The nonlifting polyp sign of invasive colon cancer is considered highly sensitive and specific for cancer extending beyond the mid-submucosa. However, prior interventions can cause adenomas to become nonlifting due to fibrosis. It is unclear whether nonlifting adenomas can be successfully treated endoscopically. The aim of this study was to evaluate outcomes in a referral practice incorporating a standardized protocol of attempted endoscopic resection of nonlifting lesions previously treated by biopsy, polypectomy, surgery, or tattoo placement. Patients and Methods. Retrospective review of patients undergoing colonoscopy by one endoscopist at two hospitals found to have nonlifting lesions from prior interventions. Lesions with biopsy proven invasive cancer or definite endoscopic features of invasive cancer were excluded. Lesions ≥ 8 mm were routinely injected with saline prior to attempted endoscopic resection. Polypectomy was performed using a stiff snare, followed by argon plasma coagulation (APC) if necessary. Results. 26 patients each had a single nonlifting lesion with a history of prior intervention. Endoscopic resection was completed in 25 (96%). 22 required snare resection and APC. 1 patient had invasive cancer and was referred for surgery. The recurrence rate on follow-up colonoscopy was 26%. All of the recurrences were successfully treated endoscopically. There was 1 postprocedure bleed (4%), no perforations, and no other complications. Conclusions. The majority of adenomas that are nonlifting after prior interventions can be treated successfully and safely by a combination of piecemeal polypectomy and ablation. Although recurrence rates are high at 26%, these too can be successfully treated endoscopically.