P1.006. Improving Cellular Yield During Endoscopic Brush Sampling in Patients With Barrett Esophagus by Not Resheathing - a Simple Modification

Abstract

Abstract Topic Benign Disease: Barrett’s Esophagus: Pathology and Pathophysiology; Non-invasive Neoplasia Background Brush cytology allows sampling of broad mucosal areas. It has various gastrointestinal indications such as malignancy, Barrett’s esophagus and Helicobacter pylori infection. During endoscopy, the brush bristles exit a protective sheath. After sampling, the bristles retract back into the sheath. While few studies have explored the role of the plastic sheath on cellularity, loss of cellularity during sheath retraction is observed in the literature. As diagnostic accuracy depends on cellularity yield, this study investigated whether not retracting the bristles into the sheath is feasible and results in better cellular yield and diagnostic accuracy. Methods Patients with Barrett esophagus undergoing endoscopy were included. Brush samples were taken with either brush retraction (=control) or no retraction (=intervention). The modified technique has been filmed for standardisation purposes. Samples were stored in Cytolyt cell medium and directly transported to the department of Pathology for cytological evaluation and formalin-fixation for cellblock. Cellularity results were defined as ‘insufficient’, ‘low’, ‘moderate’ and ‘high’. Cellularity results were bundled in two groups ‘insufficient-to-low’ and ‘moderate-to-high’ in order to facilitate statistical analysis using Fisher’s exact test at 95% confidence interval. Diagnostic accuracy was evaluated whether the brush cytology could confirm diagnosis of Barrett esophagus. Results A total of 17 patients with Barrett esophagus were included during a one-year period for a total of 32 brush samples. When brush retraction was performed, cellularity was insufficient-to-low in 47.4% (9 brushes) and moderate-to-high in 52.6% (10 brushes). When the unsheathed technique was used, cellularity was moderate-to-high in 100% (13 brushes). There were no brushes that yielded insufficient-to-low cellularity. When comparing the two techniques, there is more cellular yield when not retracting (p = 0.0042). Diagnostic accuracy was 52.6% when brush retraction was performed, while diagnostic accuracy increased to 61.5% with the unsheathed technique. This result was not statistically significant (p-value 0.72). Conclusion This small-scale study points towards better cellular yield by not retracting the brush into the sheath during endoscopic brush sampling. A larger sample size is needed to confirm the benefit in diagnostic accuracy and whether these findings can be applied for other indications of brush cytology.