PTH-003 Does size matter: how accurate are our polyp-sizing methods?

Introduction Correct sizing of a colonic polyp at the time of lower gastrointestinal (LGI) endoscopy is key in dictating polypectomy method, use of tattoo, and future surveillance in colorectal cancer prevention (CRC). There are no accepted standards for how to size a polyp and therefore it is endoscopist-dependent and subject to inter-observer variation. Visual estimation (VE), or the use of open forceps (OF) to are the two most widely-used methods. There are limited studies on polyp-sizing at LGI endoscopy but they would suggest that the use of a measurement guide such as OF would improve size estimation. Our aim was to ascertain which polyp-sizing technique method is preferred. A secondary aim was to see if those using OF knew the size of the forceps being used. Methods A 6 question survey was completed by endoscopists and nursing staff from Endoscopy Departments in 3 hospitals in West Kent using an online survey tool. Questions included asking for the respondent to identify how to position the scope and forceps based on photographs, and to identify the correct size of the OF when fully open. The size of the open forceps of the Boston Scientific© Standard 2.8 mm Radial JawTM4 single-use biopsy forceps was measured against a standard UK ruler. Results There were a total of 27 respondents: 81% were endoscopists and 19% nurse observers. 6 trainee endoscopists completed the survey. 67% used visual estimation to size polyps and 30% used the open forceps technique. There was a discrepancy in how respondents would position the scope and forceps to size the polyp with no statistical significance. 22% admitted they would not know which forceps were used in their department. Only 22% correctly identified the size of the OF (range 2 mm–8 mm). Of those endoscopists who perform >500 LGI endoscopies/year, 50% used OF and 50% VE. This group were more likely to correctly size OF. Trainee endoscopists performing only 50–100 LGI endoscopies mostly used VE which raises the question of whether they correctly size polyps given their limited experience. Conclusion This small observational survey shows that the majority of endoscopists are likely to be incorrectly sizing polyps at LGI endoscopy. The majority of our respondents use VE which has been previously shown to be inferior to the OF technique. However, as demonstrated in this survey, our endoscopy staff do not know the correct size of the OF. Incorrect polyp sizing at LGI endoscopy could have far-reaching consequences on CRC prevention. Further work should be considered to develop a standardized technique for polyp sizing at the time of LGI endoscopy and to determine if training should focus more on this important skill.