Colon Polyps
Conditions
Keywords
Large colon polyps, Polyp resection, Colon cancer screening, Colonoscopy, Endoscopic mucosal resection
Brief summary
The effectiveness of colonoscopy in reducing colorectal cancer mortality relies on the detection and removal of neoplastic polyps. Because the risk of prevalent cancer and of transition to cancer increases with polyp size, effective and safe resection of large polyps is particularly important. Large polyps ≥20mm are removed by so-called endoscopic mucosal resection (EMR) using electrocautery snares. Resection of these large polyps is associated with a risk of severe complications that may require hospitalization and additional interventions. The most common risk is delayed bleeding which is observed in approximately 2-9% of patients. A recent retrospective study suggests that closure of the large mucosal defect after resection may decrease the risk of delayed bleeding. However, significant uncertainty remains about the polypectomy techniques to optimizing resection and minimizing risk. Important aspects that may affect risk include clipping of the mucosal defect and electrocautery setting.
Detailed description
Aim 1. The primary aim of the study is to compare the rate of delayed bleeding complications in patients undergoing endoscopic resection of large polyps between: * A) Closing the mucosal defect after resection (Clip group) and * B) Not closing the mucosal defect after resection (No clip group). Aim 2. The secondary aim of the study is to compare the rate of overall complications in patients undergoing endoscopic resection of large polyps between two cautery settings: * A) Low power coagulation and * B) Endocut.
Interventions
PROCEDUREClip closure
Patients will be randomized to either closing the mucosal defect after polyp removal or not closing the mucosal defect using clips (main intervention and comparison). The resection margins will be approximated using clips. Complete closure is defined as approximated margins with less than 1cm gap between clips. All patients will further be randomized to two different settings of electrocautery (EndoCut or Coagulation) to standardize otherwise variable electrocautery practice, and for explorative analysis.
Sponsors
Dartmouth College
Boston Scientific Corporation
White River Junction Veterans Affairs Medical Center
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to 89 Years
Healthy volunteers
No
Inclusion criteria
* Any patient ≥18 and ≤89 who presents for a colonoscopy and who does not have criteria for exclusion * Patients with a ≥20mm non-pedunculated colon polyp
Exclusion criteria
* Patients with known (biopsy proven) invasive carcinoma in a potential study polyp * Pedunculated polyps (as defined by Paris Classification type Ip or Isp) * Patients with ulcerated depressed lesions (as defined by Paris Classification type III) * Patients with inflammatory bowel disease * Patients who are receiving an emergency colonoscopy * Poor general health (ASA class\>3) * Patients with coagulopathy with an elevated INR ≥1.5, or platelets \<50 * Poor bowel preparation * Pregnancy
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Number of Participants With Delayed Bleeding Complications | 30 days following a study polyp resection | A bleeding event that occurred within 30 days after completion of the colonoscopy with a study polyp resection and is associated with a decrease in hemoglobin by at least 2gm, hemodynamic instability, presentation to the ED, need for hospitalization, repeat colonoscopy, or other interventions. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| The Overall Number of Complications | 30 days | Overall complications are defined as an aggregate of all complications that occur at the time of the procedure (immediate complications) or during 30 days of follow-up. They include delayed bleeding complications, perforation, postpolypectomy syndrome, and clinical events that require an ED visit, admission to the hospital, additional testing or an intervention. |
| Complete Study Polyp Resection Rate | 6 months | Rate of complete study polyp resection at the initial colonoscopy and at first follow-up endoscopy |
| Polyp Recurrence Rate | 3 months to 5 years | Rate of recurrent polyp at the resection site after complete polyp resection. |
| The Number of Complications Associated With Clip Use | 30 days | Incidence of complications associated with application of clips. |
Other
| Measure | Time frame | Description |
|---|---|---|
| Measured Factors Associated With Resection Complications | 30 days | Factors that may be associated with complications, including electrocautery setting, polyp size, location of the polyp in the colon (right, left, rectum), histology, polyp morphology, time required for resection. |
| Measured Factors Associated With Incomplete Resection or Recurrence of Polyps | 5 years | Factors that may be associated with incomplete resection may include prior attempts of removal, use of adjunctive argon plasma coagulation for residual polyp removal, polyp size, location, histology. |
Countries
United States
Participant flow
Pre-assignment details
Some of the inclusion/exclusion criteria, e.g. polyp size, poor bowel preparation, could not be assessed until after the start of the colonoscopy. Therefore, informed consent was obtained and the patient enrolled in the study prior to the procedure. Only when it was determined that the patient was eligible for the study were they then randomized.
Participants by arm
| Arm | Count |
|---|---|
| Clip Closure + EndoCut Clipping of the mucosal defect after resection of a ≥20mm non-pedunculated study polyp using clips. Resection is done using the EndoCut electrocautery mode.
Clip closure: Patients will be randomized to either closing the mucosal defect after polyp removal or not closing the mucosal defect using clips (main intervention and comparison). The resection margins will be approximated using clips. Complete closure is defined as approximated margins with less than 1cm gap between clips. All patients will further be randomized to two different settings of electrocautery (EndoCut or Coagulation) to standardize otherwise variable electrocautery practice, and for explorative analysis. | 227 |
| Clip Closure + Coagulation Clipping of the mucosal defect after resection of a ≥20mm non-pedunculated study polyp using clips. Resection is done using the Coagulation electrocautery mode.
Clip closure: Patients will be randomized to either closing the mucosal defect after polyp removal or not closing the mucosal defect using clips (main intervention and comparison). The resection margins will be approximated using clips. Complete closure is defined as approximated margins with less than 1cm gap between clips. All patients will further be randomized to two different settings of electrocautery (EndoCut or Coagulation) to standardize otherwise variable electrocautery practice, and for explorative analysis. | 231 |
| No Clip Closure + EndoCut No clipping of the mucosal defect after resection of a ≥20mm non-pedunculated study polyp. Resection is done using the EndoCut electrocautery mode. | 237 |
| No Clip Closure + Coagulation No clipping of the mucosal defect after resection of a ≥20mm non-pedunculated study polyp. Resection is done using the Coagulation electrocautery mode. | 233 |
| Total | 928 |
Withdrawals & dropouts
| Period | Reason | FG000 | FG001 | FG002 | FG003 |
|---|---|---|---|---|---|
| Overall Study | no 30-day follow-up data | 0 | 3 | 3 | 3 |
Baseline characteristics
| Characteristic | No Clip Closure + Coagulation | Total | Clip Closure + EndoCut | Clip Closure + Coagulation | No Clip Closure + EndoCut |
|---|---|---|---|---|---|
| Additional Polyps (any size) No | 129 Participants | 520 Participants | 129 Participants | 128 Participants | 134 Participants |
| Additional Polyps (any size) Yes | 104 Participants | 408 Participants | 98 Participants | 103 Participants | 103 Participants |
| Age, Continuous | 65.3 years STANDARD_DEVIATION 9.8 | 65.1 years STANDARD_DEVIATION 9.6 | 64.7 years STANDARD_DEVIATION 9.7 | 65.5 years STANDARD_DEVIATION 9.2 | 64.8 years STANDARD_DEVIATION 9.8 |
| ASA Class ASA III - patient with severe systemic disease | 92 Participants | 336 Participants | 79 Participants | 81 Participants | 84 Participants |
| ASA Class ASA II - patient with mild systemic disease | 121 Participants | 513 Participants | 125 Participants | 133 Participants | 134 Participants |
| ASA Class ASA I - normal healthy patient | 20 Participants | 79 Participants | 23 Participants | 17 Participants | 19 Participants |
| Body Mass Index (BMI) | 29.1 kg/m^2 STANDARD_DEVIATION 5.6 | 29.2 kg/m^2 STANDARD_DEVIATION 6 | 29.5 kg/m^2 STANDARD_DEVIATION 6.6 | 29.0 kg/m^2 STANDARD_DEVIATION 5.6 | 29.1 kg/m^2 STANDARD_DEVIATION 6.2 |
| Electrocautery EndoCut | 0 Participants | 461 Participants | 227 Participants | 0 Participants | 234 Participants |
| Electrocautery Forced Coagulation | 230 Participants | 458 Participants | 0 Participants | 228 Participants | 0 Participants |
| Electrocautery None - did not complete study | 3 Participants | 9 Participants | 0 Participants | 3 Participants | 3 Participants |
| More Than One Study Polyp No | 222 Participants | 867 Participants | 208 Participants | 221 Participants | 216 Participants |
| More Than One Study Polyp Yes | 11 Participants | 61 Participants | 19 Participants | 10 Participants | 21 Participants |
| Periprocedural Antithrombic Medications Anticoagulants | 16 Participants | 49 Participants | 5 Participants | 15 Participants | 13 Participants |
| Periprocedural Antithrombic Medications Antiplatelet agents | 70 Participants | 232 Participants | 54 Participants | 47 Participants | 61 Participants |
| Periprocedural Antithrombic Medications None | 147 Participants | 647 Participants | 168 Participants | 169 Participants | 163 Participants |
| Procedure Sedation Moderate Sedation | 25 Participants | 116 Participants | 32 Participants | 26 Participants | 33 Participants |
| Procedure Sedation Monitored Anesthesia | 207 Participants | 806 Participants | 194 Participants | 201 Participants | 204 Participants |
| Procedure Sedation No Sedation | 1 Participants | 6 Participants | 1 Participants | 4 Participants | 0 Participants |
| Quality of Bowel Preparation Excellent | 68 Participants | 249 Participants | 62 Participants | 64 Participants | 55 Participants |
| Quality of Bowel Preparation Fair | 38 Participants | 150 Participants | 42 Participants | 34 Participants | 36 Participants |
| Quality of Bowel Preparation Good | 127 Participants | 529 Participants | 123 Participants | 133 Participants | 146 Participants |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Asian | 2 Participants | 7 Participants | 2 Participants | 2 Participants | 1 Participants |
| Race (NIH/OMB) Black or African American | 17 Participants | 62 Participants | 16 Participants | 18 Participants | 11 Participants |
| Race (NIH/OMB) More than one race | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 9 Participants | 38 Participants | 9 Participants | 9 Participants | 11 Participants |
| Race (NIH/OMB) White | 205 Participants | 821 Participants | 200 Participants | 202 Participants | 214 Participants |
| Sex: Female, Male Female | 90 Participants | 376 Participants | 92 Participants | 98 Participants | 96 Participants |
| Sex: Female, Male Male | 143 Participants | 552 Participants | 135 Participants | 133 Participants | 141 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk | EG002 affected / at risk | EG003 affected / at risk |
|---|---|---|---|---|
| deaths Total, all-cause mortality | 0 / 227 | 0 / 228 | 2 / 234 | 0 / 230 |
| other Total, other adverse events | 34 / 227 | 20 / 228 | 33 / 234 | 21 / 230 |
| serious Total, serious adverse events | 11 / 227 | 11 / 228 | 21 / 234 | 23 / 230 |
Outcome results
Primary
Number of Participants With Delayed Bleeding Complications
A bleeding event that occurred within 30 days after completion of the colonoscopy with a study polyp resection and is associated with a decrease in hemoglobin by at least 2gm, hemodynamic instability, presentation to the ED, need for hospitalization, repeat colonoscopy, or other interventions.
Time frame: 30 days following a study polyp resection
Population: As per study protocol, the primary analysis was done using clip/no clip closure as the study groups. Data for 9 patients was not available.
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| Clip Closure | Number of Participants With Delayed Bleeding Complications | 16 Participants |
| No Clip Closure | Number of Participants With Delayed Bleeding Complications | 33 Participants |
Secondary
Complete Study Polyp Resection Rate
Rate of complete study polyp resection at the initial colonoscopy and at first follow-up endoscopy
Time frame: 6 months
Secondary
Polyp Recurrence Rate
Rate of recurrent polyp at the resection site after complete polyp resection.
Time frame: 3 months to 5 years
Secondary
The Number of Complications Associated With Clip Use
Incidence of complications associated with application of clips.
Time frame: 30 days
Secondary
The Overall Number of Complications
Overall complications are defined as an aggregate of all complications that occur at the time of the procedure (immediate complications) or during 30 days of follow-up. They include delayed bleeding complications, perforation, postpolypectomy syndrome, and clinical events that require an ED visit, admission to the hospital, additional testing or an intervention.
Time frame: 30 days
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| Clip Closure | The Overall Number of Complications | 22 Participants |
| No Clip Closure | The Overall Number of Complications | 44 Participants |
Other Pre-specified
Measured Factors Associated With Incomplete Resection or Recurrence of Polyps
Factors that may be associated with incomplete resection may include prior attempts of removal, use of adjunctive argon plasma coagulation for residual polyp removal, polyp size, location, histology.
Time frame: 5 years
Other Pre-specified
Measured Factors Associated With Resection Complications
Factors that may be associated with complications, including electrocautery setting, polyp size, location of the polyp in the colon (right, left, rectum), histology, polyp morphology, time required for resection.
Time frame: 30 days