Colorectal cancer remains the third most common cause of death from cancer worldwide. Colonoscopy allows removal of adenomatous polyps is the best colorectal cancer screening, according to the adenoma-carcinoma sequence. Recent studies have reported approximately 30% of interval cancer may be incomplete polyp resection. Complete polyp resection may be particularly important when implementing new methods for surveillance colonoscopies. Cold snare polypectomy (CSP) is considered to be a safer procedure for removing subcentimeter lesions than conventional hot snare polypectomy (HSP). CSP removal of polyps sized ≤5 mm have recommended by the European Society of Gastrointestinal Endoscopy guideline as the preferred technique. Previous report said that the complete resection rate of CSP for adenomatous polyps 4-9 mm in size was comparable to that of HSP, and in the foreseeable future CSP can be one of the standard techniques for 4-9 mm colorectal polyps. However, data on complete resection of colorectal polyps 1.0-1.5 mm in size is sparse. Investigators are interested in comparison of the resection rate of cold snare polypectomy for large (10-15 mm) and small (5-9 mm) colorectal polyps using CSP.

Participantswho meet inclusion criteria will be asked to participate, investigators will include all patients with resectable polyps, but only adenomatous polyps will be included for analysis. See also inclusion and exclusion criteria.

Colonoscopy, after bowel preparation with polyethylene glycol solution was performed using standard colonoscopes (CF-HQ290I, CF-Q260AI) and polypectomy snares(13mm Captivator and 10mm Captivator II).

All procedures were performed by experienced endoscopists (each with over 1000 colonoscopies performed) including CSP. All polyps between 5 and 15mm will be removed with a polypectomy snare. Polyp size will be measured using the tip of the snare catheter (2.5mm). Difficulty of resection will be grade by polyp resection time. Following the resection, jet stream of water will be used to wash mucosal defect thoroughly. After endoscopist's attestation that polyp removal was complete by carefully observe the resection margins with near focus mode, for large lesions (10-15mm) 4 biopsies will be performed from all four quadrants of resection margins, for small lesions (5-9mm) biopsies were performed from two marginal sites located symmetrically on the left and right of the mucosal defects to confirm residual polyp tissue.

If polyp resection is complicated by bleeding (not self-sustained), no biopsies will be taken and any additional polyps that will be found during the remaining examination will be excluded from analysis. Severe bleeding that will complicate resection margins examination will be excluded from analysis, Endoscopic haemostasis will be performed when active haemorrhage continued for ≥30s.

A single research subject may have many eligible polyps. To avoid taking many biopsies, the investigators will not include more than 5 eligible polyps (the first 5 that are detected) per patient in the study.

Laboratory Analysis:

The polyps will be evaluated by experienced pathologists according to Vienna classification. Resection margins for each polyp will be recorded as: R0= adenomatous tissue free, R1=adenomatous tissue detection. Investigators will only include adenomatous polyps in the analysis. for financial requests of the resection margin biopsies. The pathological diagnosis of the biopsies will become part of the medical record. If biopsies contain adenomatous tissue the participants will be ask to return for a follow-up colonoscopy within six month.

Inclusion Criteria:

• Patient ≥40 and <85
• Provide written informed consent
• Patients are found to have colorectal polyps between 5 and 15mm in size

Exclusion Criteria:

• History of inflammatory bowel disease
• Polyposis of the alimentary tract
• Antiplatelet or anticoagulant therapy 5 days before the procedure
• Pregnancy
• Haemodialysis
• An American Society of Anaesthesiologists class III or higher
• Depressed lesions and lesions highly suspected to be cancerous based on endoscopic appearance

40 Years to 85 Years

individual participant data can be seen after article been published