WASP Classification in Diagnosis of Diminutive Colorectal Polyps

Study Overview
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Brief Summary
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Adenomas, serrated adenomas and hyperplastic polyps are polypoid lesion in the colorectum. At the present moment, all polyps should be resected endoscopically, although only adenomas and serrated adenomas, but not hyperplastic polyps have the potential to develop colorectal cancer. Some studies have investigated the value of the narrow-band imaging (NBI) on histological prediction of the polyp. This method is conducted in real time during colonoscopy, which leads to simplification of diagnostic procedures. For instance, it would be conceivable to resect diminutive polyps and discard them without further assessment by a pathologist. One problem in this context is a correct differentiation between hyperplastic polyps and serrated adenomas. These two polyp entities are known to show similar optical features. However, while serrated adenomas are premalignant lesions hyperplastic polyps have benign histology and never develop into cancer. It is therefore important to sufficiently distinguish hyperplastic polyps from serrated lesions. In this study the investigators want to investigate whether the use of NBI would be capable to get accuracy of optical polyp predictions by more than 90% using the WASP (Workgroup serrAted polypS and Polyposis) classification. NBI is a light filter tool which can be activated by pressing a button at the endoscope. The use of NBI leads to an endoscopic picture which appears blue and enables endoscopists to better assess surface structures and vascular patterns. All polyps will be resected and send to pathology for further microscopic assessment. After completing the trial the investigators aim to compare accuracy of the optical diagnosis.

Official Title
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Efficacy of WASP Classification in the Histological Evaluation of Diminutive Colorectal Polyps

Conditions
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Diminutive Colorectal Polyps

Intervention / Treatment
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* Device: NBI


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients aged more than 18 years old Patients with at least one diminutive colorectal polyp Exclusion Criteria: Patients with poor bowel preparation Paitents with history of colorectal surgery, familial adenomatous polyposis or inflammatory bowel disease Patients with advanced colorectal cancer Patients with missed histology information of resected polyps or missed resected specimen Patients with emergency operation during colonoscopy Patients with unfinished colonoscopy due to any reason

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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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Diagnostic
Intervention Model: Single Group Assignment
Interventional Model Description: Colonoscopy with NBI using the WASP classification
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: NBI assessment using the WASP classification<br> | Device: NBI<br>* optical assessment of diminutive colorectal polyps by NBI mode using the WASP assessment<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Accuracy of Surveillance time prediction of patients with at least one diminutive polyps under high confidence of diagnosis |  | Within two weeks after polypectomy | 
| Negative predictive value of diminutive polyps located in rectum and sigmoid colon under high confidence of diagnosis |  | Within two weeks after polypectomy | 
| Accuracy of WASP classification in histological prediction of diminutive polyps under high confidence of diagnosis |  | Within two weeks after polypectomy | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Learning curve of accuracy of endoscopists using NBI in assessment of diminutive polyps |  | Within two weeks after polypectomy | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Narrow band imaging, WASP classification, Diminutive colorectal polyps