Enhancing Polyp Detection through Training: Session 1

1. EQUIPTraining session 1 Improving polyp/adenoma detection

2. Background • No prospective methods to increase ADR • Detection of flat lesions not reported

3. Hypothesis Intensive training (detection & classification) Increase in adenoma detection

4. Session I Objectives • Importance • Definition • Prevalence • Histopathology • Detection Methods • Subtle clues to flat polyps • Colonoscopy Techniques

5. Paris shape classification “Flat” polyps: Lesions with < 2.5mm elevation (width of snare catheter/bx cable)

6. Definitions • Flat • Less than 2.5mm of elevation • Depressed • Base lower than normal mucosa height • Well demarcated; round or star shaped

7. Flat and depressed lesions • 1819 VA patients • 9.3% prevalence • 15% of all neoplasms • 54% of superficial carcinomas • (OR 11.1; 95%CI, 4.98-24.8) • 1/3 of depressed lesions contained carcinoma Soetikno et al; JAMA 2008

8. Prevalence of Flat Polyps 27,400 colonoscopies Flat adenoma 5.3% Among all adenomas Polypoid 74% Flat 26% More likely in right colon (OR 2.92) Risk of advanced histology similar Unless depressed (OR 10.56) • Blanco et al. Endoscopy 2010;42:279

9. Polypoid (n= 2463) 1155 non-neoplastic 1262 tub. adenoma 33 villous adenoma 13 carcinoma Flat (n = 289) 80 non-neoplastic 195 tub. adenoma 5 villous 9 carcinoma Depressed, n = 18 12 tubular adenomas 6 carcinomas NO non-neoplastic Flat polyp pathology Soetikno et al; JAMA 2008

10. Detection methods Subtle clues to detection Bowel preparation Colonoscopy techniques Washing, working the folds Withdrawal Clear caps Optical enhancement ?

11. Subtle clues • Subtle color differences (red or pale) • Spontaneous hemorrhage/friability • Deformity of colon wall • Absence of vascular network ASGE Learning Library: Diagnosis of Flat and Depressed Colorectal Neoplasms; 2006

12. Subtle clues: Video ASGE Learning Library: Diagnosis of Flat and Depressed Colorectal Neoplasms; 2006

14. Detection methods • Colonoscopy technique • Withdrawal time ? • Washing • Bowel prep score • “Working” the folds • Clear Caps

15. Withdrawal Time Mandating longer WD time does NOT increase ADR ADR after Mandate Compliance w/ mandate Sawhaney Gastro 2008;135;1892

16. Colonoscopy technique • High detector vs. low detector • Percentage of mucosa visualized (estimate) • 90.8% vs. 63.3%; p <0.001 • Mean withdrawal time • 8 min 55 sec vs. 6 min 41 sec; p = 0.02 • More retroflex exams (9 vs. 6) • Re-examine prox. side rectal valves in all 9 (15 – 40 seconds) Rex D, GIE; 2000; Vol 51, No 1

17. Prep Quality • Missed CRC • Retrospective data review; 5055 colonoscopies • 17/286 cancers missed by colonoscopy • 6/17 (3.5%) incomplete due to “poor prep” • 4/17 (2.4%) identified but not recognized as malignant • Flat and depressed neoplasms • Detection lower with inadequate bowel prep • Small adenoma detection • Retrospective review; 93,000 • Adequate prep (76.9%) more likely detect • “Suspected neoplasia” • Lesions < 9mm • No difference in lesions >9 mm

18. Boston Bowel Preparation Score

20. Hidden flat lesions ASGE Learning Library: Diagnosis of Flat and Depressed Colorectal Neoplasms; 2006

21. “Working” the folds Same day virtual and optical colonoscopy (1233 patients; 210 adenomas > 6mm) • 21 adenomas > 6mm missed on OC • 7 = advanced lesions • 15 = non-rectal neoplasia (other 6 in rectum) • 14 located on folds (10 back, 4 front) • 1 located inner aspect of a flexure

22. Withdrawal technique

23. “Working” the folds

24. Clear caps Retractable clear cap vs. NBI for 2nd colonoscopy in patients with known polyps Interval increase in adenoma detection by size and shape Horiuchi et al. CGH 2010;8:379

25. Clear caps

26. Summary • Flat polyps exist • There are subtle clues to detect flat polyps • Color, friability, wall deformity, vessel changes • Good colonoscopy technique is needed • Washing • Clear caps • Working the folds