Endoscopic Resection of Large Colorectal Polyps: An Observational Cohort Study

Study Overview
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Brief Summary
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This protocol describes a prospective cohort study. It addresses an important challenge in the prevention of colorectal cancer: how to safely and effectively remove large polyps.

Detailed Description
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Over recent years, a number of studies have been published that have highlighted factors associated with improved efficacy and safety of large polyp resection. Almost all of these studies originate from one large Australian cohort. It is unclear, whether the results are generalizable to other populations. It is important to understand if these findings can be duplicated, to further build on the gained knowledge. At the same time the technology of endoscopic resection is evolving. Established in 2012, the Large Polyp Study group aims to prospectively examine outcomes related to endoscopic large polyp removal. Enrollment of an ongoing randomized trial of 920 patients has just been completed and a second trial is planned. The primary aim of both trials is to understand whether a specific intervention will reduce the risk of adverse events. The added observational study will complement the trials in different ways: It will enroll patients who might not have been eligible for the trials and allow the application of other resection techniques. The observational study will therefore better represent the average patient who undergoes resection of a large polyp. Furthermore, it will add sample size to examine secondary outcomes with greater power. This is a continuation of NCT01936948 (Safety of Endoscopic Resection of Large Colorectal Polyps: A Randomized Trial) as a observational cohort. The continuation was approved by the institutional IRB as part of the initial RCT. At this point the investigators document the observational arm as its own study in this registry.

Official Title
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Large Polyp Study (LPS) III - Endoscopic Resection of Large Colorectal Polyps: An Observational Cohort Study

Conditions
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Colonic Polyp, Colonoscopy, Complication, Recurrence

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Any patient ≥18 who presents for a colonoscopy and who does not have criteria for exclusion Patients with a ≥20mm colon polyp Exclusion Criteria: Patients who are receiving an emergency colonoscopy Patients with coagulopathy with an elevated INR ≥1.5, or platelets <50 Poor bowel preparation Pregnancy

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Incidence of severe complications | Aggregate of all severe adverse events that occur at the time of the procedure or during and up to 14 days of follow-up. Severe adverse events include bleeding, perforation, postpolypectomy syndrome, and clinical events that require an admission to the hospital. | Up to 14 days following the procedure. | 
| Completeness of polyp resection | Complete polyp removal is defined as removal of all visible polyp tissue at the end of the EMR, as assessed by the endoscopist. | During the procedure | 
| Polyp recurrence | Presence of biopsy proven neoplastic polyp tissue at the EMR resection site at surveillance colonoscopy following complete polyp resection. | Up to 5 years (at next scheduled surveillance colonoscopy). | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Severe bleeding complications | Severe bleeding is defined as the need for hospitalization, transfusion, a repeat colonoscopy or sigmoidoscopy, surgery, or interventional radiologyUp to 14 days following the procedure. | Up to 14 days following the procedure. | 
| Perforation | Defined as a complete hole, or full-thickness resection of the muscularis propria (Sydney Classification of Deep Mural Injury Type IV) | Up to 14 days following the procedure. | 
| Postpolypectomy syndrome | Defined as abdominal pain severe enough to warrant an ED visit or hospital admission and presence of leukocytosis and/or required treatment with antibiotics. | Following the procedure up to 14 days. | 
| Efficacy of submucosal injectate | Volume of solution per lesion size (mL/cm2), time of resection. | During the procedure. | 
| Intraprocedural bleeding | Immediate bleeding that requires endoscopic intervention to stop the bleeding (e.g. clip placement or snare tip soft coagulation or coagulation grasper). | During the procedure | 
| Need for colon resection | Patients who require surgery for polyp removal or as a result of complications related to the EMR or follow up procedures. | Up to 3 years following the procedure. | 
| Technical skill of the endoscopist | To perform video based assessment of endoscopic resection skills | During the procedure |