Endoscopic Therapy of Colorectal Polyps Douglas K Rex Indiana - PowerPoint PPT Presentation

Endoscopic Therapy of Colorectal Polyps Douglas K Rex Indiana University Medical Center Indianapolis, IN

Topics listed in the brochure  Realistic miss rate of significant polyps during colonoscopy  Is withdrawal time a realistic quality indicator?  Is repeat colonoscopy ever justified for missed polyps?  Does the data showing the reduction of colon cancer by screening colonoscopy factor in missed polyps and flat lesions?  What to do with diminutive polyps?  Not covered: Endoscopic therapy of colorectal polyps (but we can discuss it in the Q and A)

Realistic miss rate for “significant polyps”  Rex tandem colonoscopy study: 6% (2/32) for adenomas ≥ 10 mm  CTC studies – Pickhardt: 12% – Van Gelder: 17%  In clinical practice you can’t measure the miss rate: you can only infer it from what is detected (the adenoma detection rate) – Barclay (Rockford) and Chen (Indiana): a group of endoscopists misses more than half of the large adenomas

Why don’t we measure large adenoma detection rates?  Harder to specify the expected range and acceptable thresholds  Subject to operator error in measuring polyp size  Have to examine 5-10 times as many records  In both the Rockford and Indiana studies large adenoma detection correlated with overall adenoma detection

Is withdrawal time a realistic quality indicator?  Primary measure of the quality of mucosal inspection is the ADR  Withdrawal time is a secondary indicator; it does not explain all variation in ADR – Consistent statistical correlation across studies – Increasing WT increased ADR in the Rockford study (not in a study from Boston)

Withdrawal time as a quality indicator  Easy to measure (record cecal intubation times – WT counted only if no polypectomy or biopsies performed)  Emerging as a standard of care issue despite warnings of USMSTF and ASGE/ACG  Should be measure in all patients  Should be first focus if the ADR is low

Does the reduction of colon cancer by screening colonoscopy factor in missed polyps and flat lesion?  Which data are you speaking of? – No RCT of screening colonoscopy – 1 cohort study of screening colonoscopy (Kahi et al CGH 2009) – Multiple adenoma cohorts: NPS, U.S. dietary trials, U.S. chemoprevention trials, Funen adenoma study – Case control studies: Brenner, Muller – Sonnenberg, Singh, Baxter

Does the reduction of colon cancer by colonoscopy factor in missed polyps and flat adenomas?  Of the various causes of interval cancers, quantitative assignment of the causes is not currently possible

Why do interval cancers occur?

What to do with diminutive polyps?  Current policy: resect all except ok to sample multiple diminutive rectosigmoid polyps that look hyperplastic  Future policies: – Leave diminutive HP polyps in the distal colon in place; use photo as documentation of histology – “Resect and discard” diminutive polyps

Accurate real time histology techniques  Narrow band imaging with and without HM  FICE  I Scan  Confocal laser microscopy  Endocytoscopy  Chromoendoscopy with high magnification