Underwater Resection of Non-pedunculated Colorectal Lesions

Underwater resection of eligible lesions will be performed with air exclusion (air will be suctioned and completely removed) without submucosal injection in a partially collapsed colon lumen filled with water. Water will be infused with the foot pedal to facilitate visualization during UR and there will be no limit to the amount of water infused. Hot and cold resection techniques will be utilized.

Conventional polypectomy of eligible lesions will be performed in a gas distended colon. Hot and cold resection techniques will be utilized. Submucosal fluid injection with a solution containing hydroxyethyl starch, dilute epinephrine and a contrast agent may be used with conventional techniques for large (≥1cm) and/or flat lesions. There will be no limit to the amount of submucosal injection used.

Standard polypectomy will be performed for diminutive (\<6mm), pedunculated and semi-pedunculated lesions that do not fall under the inclusion criteria for the study. These lesions will be removed in a gas distended colon with a 9mm firm, thin wire cold snare or snare electrocautery for large (≥1cm) lesions.