Endoscopic Resection of Large Colorectal Polyps: An Observational Cohort Study


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.

Full Title of Study: “Large Polyp Study (LPS) III – Endoscopic Resection of Large Colorectal Polyps: An Observational Cohort Study”

Study Type

  • Study Type: Observational [Patient Registry]
  • Study Design
    • Time Perspective: Prospective
  • Study Primary Completion Date: May 2025

Detailed Description

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.

Clinical Trial Outcome Measures

Primary Measures

  • Incidence of severe complications
    • Time Frame: Up to 14 days following the procedure.
    • 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.
  • Completeness of polyp resection
    • Time Frame: During the procedure
    • Complete polyp removal is defined as removal of all visible polyp tissue at the end of the EMR, as assessed by the endoscopist.
  • Polyp recurrence
    • Time Frame: Up to 5 years (at next scheduled surveillance colonoscopy).
    • Presence of biopsy proven neoplastic polyp tissue at the EMR resection site at surveillance colonoscopy following complete polyp resection.

Secondary Measures

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

Participating in This Clinical Trial

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

Gender Eligibility: All

Minimum Age: 18 Years

Maximum Age: N/A

Are Healthy Volunteers Accepted: Accepts Healthy Volunteers

Investigator Details

  • Lead Sponsor
    • White River Junction Veterans Affairs Medical Center
  • Provider of Information About this Clinical Study
    • Principal Investigator: Dr. Heiko Pohl, Associate Professor of Medicine – White River Junction Veterans Affairs Medical Center
  • Overall Official(s)
    • Heiko Pohl, MD, Principal Investigator, White River Junction Veterans Affairs Medical Center
  • Overall Contact(s)
    • Heiko Pohl, MD, 8022959363, heiko.pohl@va.gov

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