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PWE-032 Advanced neoplasia yield in patients undergoing colonoscopy after screening flexible sigmoidoscopy: are the current referral criteria correct?
  1. R Rameshshanker1,
  2. F Purchiaroni,
  3. A Crudeli,
  4. A Wilson,
  5. S Thomas-Gibson,
  6. N Suzuki,
  7. A Humphries,
  8. A Haycock,
  9. BP Saunders
  1. Wolfson Unit for Endoscopy, St Mark’s Hospital, London, UK


Introduction Currently patients undergoing a “Bowel Scope” (BS)screening are referred for colonoscopy if the following criteria are met: polyps>1 cm, villous histology, high grade dysplasia 3 or more adenomas, >20 hyperplastic polyps and patient related factors causing an incomplete examination ( discomfort or poor access).

Objective To assess the proportion of patients who had a significant polyp (advanced adenoma=adenoma >1 cm, villous or high grade dysplasia on histology) in the proximal colon when referred for a screening colonoscopy after a Bowel Scope examination.

Method A retrospective cross sectional study of 9960 patients who underwent BS screening between July 2013 -July 2016 at our Bowel Cancer Screening Centre was performed. Epidemiology, procedural and polyp data were retrieved from the endoscopy data base.

Results520 (5.2%) patients had a screening colonoscopy as per the BCS protocol. Median age was 55 years with male: female 2:1. The clear majority of BS examinations reached as far as the descending colon (82%). 351/520 (68%) patients had at least one advanced adenoma (AA) in the distal colon. Overall prevalence of distal AA was 3.2% (351/9960).

Caecal intubation was achieved in 98% (510/520) of screening colonoscopies. At least one adenoma or a sessile serrated adenoma/polyp (SSA/P) was detected, proximal to the extent of BS examination in 45% (232/520) of patients, when they had a colonoscopy. Table 1 summarises the prevalence of synchronous proximal colonic pathology.

The majority (68%, 351/520) of the colonoscopies were performed due to the presence of AA in the distal colon. Of these 351 patients, 52 (14.8%) had a synchronous proximal colonic AA and 20 had a synchronous SSA/P (5.7%). Only 5 patients had an advanced SSA/P (polyp >1 cm or with dysplasia) in the proximal colon (1.4%). Presence of distal AA was significantly associated with proximal colonic AA (p=0.0006). However, there were no associations between distal AA and proximal SSA/P (p=0.47) or advanced SSA/P (p=NS)

Conclusion Distal colonic AA are a marker of synchronous proximal colonic adenomas and SSA/Ps. When colonoscopies were performed for other indications (non-adenomatous polyp >1 cm, multiple distal HP polyps) the yield in the proximal colon was significantly smaller. These “soft” indications for colonoscopy accounted for a significant additional workload that appears unjustified.

Disclosure of Interest None Declared

  • Advanced adenoma
  • proximal colon
  • sessile serrated polyps

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