998 Improving Accuracy of Tumour Site Identification During Colonoscopy; a Retrospective Analysis

Abstract

Abstract Aim Colonoscopy is essential for accurate pre-operative colorectal tumour localisation. Due to variable colonic length and lack of internal landmarks, tumour site identification can be difficult, posing risks of inappropriate operations being offered. To avoid this, we must correctly identify the tumour site on endoscopy in >95% of patients as per BSG guidelines. In 2019, accuracy levels compared to radiology and histology fell significantly short of this standard. We therefore made improvements to our endoscopy database and displayed relevant guidelines in endoscopy rooms. Here, we evaluate improvement in accuracy of endoscopic tumour localisation after implementation of these initiatives. Method Retrospective study of results of all colonoscopies (214) showing suspicious lesions at our trust in 2020, compared to results of counterpart radiology and histology tests, and audited against the BSG standard of >95% accurate identification of tumour position by colonic segment. Results Accuracy of endoscopic tumour localisation was 92.2% and 92.3% compared to histology and radiology respectively. Although this does not meet the national standard of >95%, it is a significant improvement from the year prior - 80.2% and 78.8% compared to histology and radiology respectively. The greatest degree of error appears in the rectum, often being confused with recto-sigmoid and sigmoid. Conclusions Guideline reminders and database improvements were crucial to increased accuracy. However, clearer definition of colonic territories is required to avoid confusion when attributing localisation. We recommend following the American guidelines in which the term ‘recto-sigmoid’ is abolished in favour of a boundary 15cm from the anal verge that represents the division between rectum and sigmoid.