S336 Significant Improvement in the Overall Sessile Serrated Adenoma Detection Rates With High Definition Colonoscopy Compared to Standard Definition Colonoscopy

Introduction: Sessile serrated adenomas (SSAs) are important premalignant lesions that are difficult to detect during colonoscopy due to poor definition, concealment by mucous caps, and flat appearance. High definition (HD) colonoscopy may uniquely aid in the detection of these inconspicuous lesions compared to standard definition (SD) colonoscopes. We performed a retrospective study to evaluate the benefit of HD colonoscopy on SSA detection rate (SSADR) in average-risk patients undergoing screening colonoscopy. Methods: Data from screening colonoscopies for patients aged 50-76 years within two years before and two years after the transition from SD colonoscopy to HD colonoscopy were compiled from our large, academic teaching center. Patients with symptoms of colorectal disease, positive occult blood test, history of colon polyps, cancer, polyposis syndrome, inflammatory bowel disease or family history of colon cancer or polyps were excluded. Patients whose endoscopists did not perform colonoscopies both before and after scope definition change were also excluded. Differences in individual endoscopist, average, and overall SSADRs with SD colonoscopy vs HD colonoscopy were also evaluated for significance. Results: A total of 3657 colonoscopies met eligibility criteria with 2012 colonoscopies from the SD colonoscopy period and 1645 colonoscopies from the HD colonoscopy period. Eleven endoscopists performed colonoscopies both before and after implementation of HD colonoscopy. Significant improvements of 2.30% in mean SSADR and 2.53% in overall SSADR were noted with HD colonoscopy (P = 0.00028 and P = 0.00849, respectively). On the individual level, three endoscopists saw significant benefit with HD colonoscopy (+5.74%, P = 0.0056; +4.50%, P = 0.0278; +4.84%, P = 0.03486). Conclusion: Our study suggests that high definition colonoscopy statistically significantly improves sessile serrated adenoma detection in the screening of average risk patients during screening colonoscopy. By improving the detection and removal of these lesions, adoption of high definition colonoscopy may reduce the significant premalignant burden of sessile serrated adenomas.Figure 1:: Endoscopist, overall, and average SSADRs during SD colonoscopy and HD colonoscopy. * denotes statistically significant difference (P <0.05)Table 1.: Endoscopist, overall, and average SSADRs with corresponding colonoscopy volumes during SD colonoscopy and HD colonoscopy.