OPTIMAL SURVEILLANCE COLONOSCOPY AFTER ENDOSCOPIC RESECTION FOR COLORECTAL ADENOMA

Abstract

We studied 1,731 patients who underwent endoscopic resection for colorectal adenoma and subsequent surveillance colonoscopy at least two times. A polyp was defined as an index lesion (IL) if it was larger than 10mm, has high-grade dysplasia or invasive cancer. The status where no neoplastic lesion more than 5mm in size was detected by surveillance colonoscopy was considered to be semi-clean colon. The cumulative hazard rate of IL before semi-clean colon exceeded 3% in 13 months after initial polypectomies. A risk factor of IL before the semi-clean colon status was achieved was the initial diagnosis of high grade dysplasia. The cumulative hazard rate of IL after the achievement of semi-clean colon exceeded 3% in 36 months after colonoscopies establishing semi-clean colon. Risk factors of IL after semi-clean colon were older patient age and the number of adenomas equal to or more than 3. We conclude that surveillance colonoscopy should be conducted annually until achieving the semi-clean colon status, and once every three years after establishing the semi-clean colon status.