Su1233 Increased Efficiency in Adenoma Detection With Screening and Surveillance Colonoscopies Over the Course of Scheduled Block

Abstract

Background: The prevalence of sessile serrated adenomas/polyps (SSA/Ps) is uncertain. Objective: Determine the prevalence of SSA/P and SSA/P with cytological dysplasia (SSA/PCD) using a known high level detector and an experienced pathologist. Design: Crosssectional screening colonoscopy study. Settings: Academic endoscopy unit. Patients and Interventions: There were 1910 average risk asymptomatic patients ≥ 50 years old who underwent screening colonoscopy between August 2005 and April 2012 by a single colonoscopist with a proven high detection rate. Slides of all lesions in the serrated class proximal to the sigmoid, and all rectal and sigmoid serrated lesions > 5mm in size were reviewed by an experienced GI pathologist. Main outcome measurements: Prevalence of SSA/P. Results: There were 1910 patients with 656 lesions in the serrated class (as defined above) removed from 389 patients. Review by the experienced GI pathologist determined a prevalence of SSA/P of 7.2%, and SSA/P-CD of 0.9% (total SSA/P prevalence 8.1%). SSA/P and SSA/PCD comprised 5.9% and 0.5% of all resected polyps. The mean size of SSA/P was 7.13mm (SD 4.66) and 51/77 (66.2%) of polyps ≥ 10mm in the serrated class were SSA/Ps. Limitation: Retrospective design. Conclusion: Using a proven high detecting colonoscopist and an experienced pathologist, we identified a high prevalence (8.1%) of SSA/P in a screening population. SSA/Ps are more common than previously believed. Polyp distribution according to size ranges per initial pathology review